CA2116389C - Method for producing thermoplastic resin sheet or film - Google Patents
Method for producing thermoplastic resin sheet or filmInfo
- Publication number
- CA2116389C CA2116389C CA002116389A CA2116389A CA2116389C CA 2116389 C CA2116389 C CA 2116389C CA 002116389 A CA002116389 A CA 002116389A CA 2116389 A CA2116389 A CA 2116389A CA 2116389 C CA2116389 C CA 2116389C
- Authority
- CA
- Canada
- Prior art keywords
- film
- sheet
- metal belt
- endless metal
- cooling roll
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 229920005992 thermoplastic resin Polymers 0.000 title claims abstract description 47
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 11
- 238000001816 cooling Methods 0.000 claims abstract description 174
- 229920005989 resin Polymers 0.000 claims abstract description 125
- 239000011347 resin Substances 0.000 claims abstract description 125
- 229910052751 metal Inorganic materials 0.000 claims abstract description 124
- 239000002184 metal Substances 0.000 claims abstract description 124
- 239000000463 material Substances 0.000 claims abstract description 28
- 238000002844 melting Methods 0.000 claims abstract description 21
- 230000008018 melting Effects 0.000 claims abstract description 21
- 239000002667 nucleating agent Substances 0.000 claims abstract description 21
- 150000001451 organic peroxides Chemical class 0.000 claims abstract description 19
- 229920001577 copolymer Polymers 0.000 claims abstract description 16
- 239000000654 additive Substances 0.000 claims abstract description 15
- 239000003208 petroleum Substances 0.000 claims abstract description 15
- 229920000642 polymer Polymers 0.000 claims abstract description 14
- 239000000843 powder Substances 0.000 claims abstract description 13
- 150000003505 terpenes Chemical class 0.000 claims abstract description 13
- 235000007586 terpenes Nutrition 0.000 claims abstract description 13
- 239000003814 drug Substances 0.000 claims abstract description 5
- 235000013305 food Nutrition 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 81
- -1 polyethylene Polymers 0.000 claims description 19
- 229920001155 polypropylene Polymers 0.000 claims description 14
- 239000004743 Polypropylene Substances 0.000 claims description 12
- 230000000996 additive effect Effects 0.000 claims description 6
- 229920001384 propylene homopolymer Polymers 0.000 claims description 6
- 150000003839 salts Chemical class 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 4
- 150000001735 carboxylic acids Chemical class 0.000 claims description 3
- 229920000139 polyethylene terephthalate Polymers 0.000 claims description 3
- 239000005020 polyethylene terephthalate Substances 0.000 claims description 3
- 239000000454 talc Substances 0.000 claims description 3
- 229910052623 talc Inorganic materials 0.000 claims description 3
- 239000004698 Polyethylene Substances 0.000 claims description 2
- 229920000573 polyethylene Polymers 0.000 claims description 2
- 238000003825 pressing Methods 0.000 claims 7
- NWXADGGHXYSLSP-IYWMVGAKSA-N (3s,4s,5s,6r)-1,8-diphenylocta-1,7-diene-2,3,4,5,6,7-hexol Chemical class OC([C@H](O)[C@@H](O)[C@H](O)[C@H](O)C(O)=CC=1C=CC=CC=1)=CC1=CC=CC=C1 NWXADGGHXYSLSP-IYWMVGAKSA-N 0.000 claims 4
- 125000000229 (C1-C4)alkoxy group Chemical group 0.000 claims 2
- 125000004209 (C1-C8) alkyl group Chemical group 0.000 claims 2
- 239000002253 acid Substances 0.000 claims 2
- 150000007513 acids Chemical class 0.000 claims 2
- 229910052736 halogen Inorganic materials 0.000 claims 2
- 150000002367 halogens Chemical group 0.000 claims 2
- 229920001519 homopolymer Polymers 0.000 claims 1
- 229940079593 drug Drugs 0.000 abstract description 3
- 239000000203 mixture Substances 0.000 description 13
- 239000000047 product Substances 0.000 description 13
- 239000003795 chemical substances by application Substances 0.000 description 10
- 230000003746 surface roughness Effects 0.000 description 9
- 239000010935 stainless steel Substances 0.000 description 8
- 229910001220 stainless steel Inorganic materials 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 6
- 239000005977 Ethylene Substances 0.000 description 6
- 229920001400 block copolymer Polymers 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 229920005604 random copolymer Polymers 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 239000013078 crystal Substances 0.000 description 4
- 238000002425 crystallisation Methods 0.000 description 4
- 230000008025 crystallization Effects 0.000 description 4
- 229920005674 ethylene-propylene random copolymer Polymers 0.000 description 4
- 239000000155 melt Substances 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 229910000975 Carbon steel Inorganic materials 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 229910001069 Ti alloy Inorganic materials 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 238000010420 art technique Methods 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 239000010962 carbon steel Substances 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 229920006038 crystalline resin Polymers 0.000 description 2
- 229940087101 dibenzylidene sorbitol Drugs 0.000 description 2
- 229920005676 ethylene-propylene block copolymer Polymers 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 239000004417 polycarbonate Substances 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 238000007493 shaping process Methods 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 229920006352 transparent thermoplastic Polymers 0.000 description 2
- FMZUHGYZWYNSOA-VVBFYGJXSA-N (1r)-1-[(4r,4ar,8as)-2,6-diphenyl-4,4a,8,8a-tetrahydro-[1,3]dioxino[5,4-d][1,3]dioxin-4-yl]ethane-1,2-diol Chemical class C([C@@H]1OC(O[C@@H]([C@@H]1O1)[C@H](O)CO)C=2C=CC=CC=2)OC1C1=CC=CC=C1 FMZUHGYZWYNSOA-VVBFYGJXSA-N 0.000 description 1
- KDGNCLDCOVTOCS-UHFFFAOYSA-N (2-methylpropan-2-yl)oxy propan-2-yl carbonate Chemical compound CC(C)OC(=O)OOC(C)(C)C KDGNCLDCOVTOCS-UHFFFAOYSA-N 0.000 description 1
- NALFRYPTRXKZPN-UHFFFAOYSA-N 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane Chemical compound CC1CC(C)(C)CC(OOC(C)(C)C)(OOC(C)(C)C)C1 NALFRYPTRXKZPN-UHFFFAOYSA-N 0.000 description 1
- DMWVYCCGCQPJEA-UHFFFAOYSA-N 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane Chemical compound CC(C)(C)OOC(C)(C)CCC(C)(C)OOC(C)(C)C DMWVYCCGCQPJEA-UHFFFAOYSA-N 0.000 description 1
- VEBFFMASUFIZKN-UHFFFAOYSA-N 2-tert-butylperoxy-3,3,5-trimethylhexanoic acid Chemical compound CC(C)CC(C)(C)C(C(O)=O)OOC(C)(C)C VEBFFMASUFIZKN-UHFFFAOYSA-N 0.000 description 1
- 241000251468 Actinopterygii Species 0.000 description 1
- 241000251730 Chondrichthyes Species 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 229920006127 amorphous resin Polymers 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 125000005843 halogen group Chemical group 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 235000011007 phosphoric acid Nutrition 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000011342 resin composition Substances 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
- B29C43/22—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of indefinite length
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
- B29C48/07—Flat, e.g. panels
- B29C48/08—Flat, e.g. panels flexible, e.g. films
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
- B29C48/911—Cooling
- B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
- B29C48/9145—Endless cooling belts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
- B29C48/911—Cooling
- B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
- B29C48/915—Cooling of flat articles, e.g. using specially adapted supporting means with means for improving the adhesion to the supporting means
- B29C48/9155—Pressure rollers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
- B29C59/02—Surface shaping of articles, e.g. embossing; Apparatus therefor by mechanical means, e.g. pressing
- B29C59/04—Surface shaping of articles, e.g. embossing; Apparatus therefor by mechanical means, e.g. pressing using rollers or endless belts
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
- C08K5/0083—Nucleating agents promoting the crystallisation of the polymer matrix
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/14—Peroxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
- B29C48/911—Cooling
- B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
- B29C48/914—Cooling of flat articles, e.g. using specially adapted supporting means cooling drums
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
- B29C48/911—Cooling
- B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
- B29C48/915—Cooling of flat articles, e.g. using specially adapted supporting means with means for improving the adhesion to the supporting means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
- B29K2023/10—Polymers of propylene
- B29K2023/12—PP, i.e. polypropylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0018—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular optical properties, e.g. fluorescent or phosphorescent
- B29K2995/0022—Bright, glossy or shiny surface
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0018—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular optical properties, e.g. fluorescent or phosphorescent
- B29K2995/0026—Transparent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0037—Other properties
- B29K2995/0072—Roughness, e.g. anti-slip
- B29K2995/0073—Roughness, e.g. anti-slip smooth
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2457/00—Characterised by the use of unspecified polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C08J2457/02—Copolymers of mineral oil hydrocarbons
Abstract
Disclosed is a method for producing a thermoplastic resin sheet or film, wherein a raw resin material to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin and an organic peroxide is melted under heat to form a resin sheet or film, the resulting resin sheet or film is brought into contact with and adhered to the outer surface of a cooling roll having a mirror-finished surface or the outer surface of an endless metal belt having a mirror-finished surface and then moved along with the roll or the belt, and thereafter it is inserted, pressed and cooled between the outer surface of said cooling roll and the outer surface of said endless metal belt.
Also disclosed is a method for producing a thermoplastic resin sheet or film, wherein a raw resin material to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline polypropylenic copolymer is melted under heat to form a resin sheet or film, the resulting resin sheet or film is inserted between a cooling roll having a mirror-finished surface and an endless metal belt having a mirror-finished surface, then it is moved and cooled while being kept in contact with the outer surface of said cooling roll between said cooling roll and said endless metal belt, and thereafter it is pressed from the inside of said endless metal belt, then it is released from the contact with said cooling roll, and it is further moved while being kept adhered to said endless metal belt and then peeled from the belt. The non-oriented sheet or film thus produced, having a high surface gloss, a high surface smoothness and a high transparency, is suitable for wrapping foods, medicines. etc.
Also disclosed is a method for producing a thermoplastic resin sheet or film, wherein a raw resin material to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline polypropylenic copolymer is melted under heat to form a resin sheet or film, the resulting resin sheet or film is inserted between a cooling roll having a mirror-finished surface and an endless metal belt having a mirror-finished surface, then it is moved and cooled while being kept in contact with the outer surface of said cooling roll between said cooling roll and said endless metal belt, and thereafter it is pressed from the inside of said endless metal belt, then it is released from the contact with said cooling roll, and it is further moved while being kept adhered to said endless metal belt and then peeled from the belt. The non-oriented sheet or film thus produced, having a high surface gloss, a high surface smoothness and a high transparency, is suitable for wrapping foods, medicines. etc.
Description
METHOD FOR PRODUCING THERMOPLASTIC RESIN SHEET OR FILM
FIELD OF THE INVENTiON
The present invention relates to a method for efficiently producing a non-stretched, super-transparent sheet or film of a thermoplastic resin, which is favorable to wrapping materials for foods and medicines, etc.
PRIOR ART AND BACKGROUND OF THE INVENTION
Sheets or films made of crystalline thermoplastic resins, especially polypropylene resins, have different physical properties such as transparency, depending on the crystalline morphology thereof. Heretofore, the use of polypropylene resins has been limited though the resins have excellent physical properties such as heat resistance, moisture-proofness and oil resistance and they are lightweight and are cause no environmental pollution. This is because when the resins are shaped into sheets or further into containers from the shaped sheets, the sheets and the containers have poor transparency.
In order to make polypropylene resin sheets transparent, it is necessary to make the both surfaces of the sheet glossy and additionally to make the inside of the sheet transparent. To make the both surfaces of the sheet glossy,for example, there are known a method of transferring a roll mirror face to them, a method of transferring a metal mirror face to them using an endless belt having the face, a method of increasing the surface gloss of a melt web extruded from a die, etc. On the other hand, in order to make the inside of the sheet transparent, for example, there are known (a) a method of inhibiting crystallization of the sheet or letting the sheet have fine crystals (having a particle size smaller than the minimum wavelength of visible rays) by modifying the raw materials, (b) a method of inhibiting crystallization of the sheet by rapidly cooling it, (c) a method of breaking the crystals in the sheet by stretching or orientation, etc.
Accordingly, various methods comprised of these means as combined have heretofore been proposed. For instance, there has been proposed a method of transferring a roll mirror face to the surfaces of a resin sheet while a nucleating agent is added to the raw resin, whereby the both surfaces of the resin sheet are made glossy while the inside of the sheet is made transparent.
According to the method, however, it is difficult to form a thin sheet and the transparency of the sheet formed is not complete.
Apart from the above, another method has also been proposed, in which a roll mirror face is transferred to the both surfaces of a resin sheet while the sheet is rolled under pressure. According to the method, however, since the sheet is stretched and oriented by rolling under pressure, there occur various problems that the physical properties of the sheet in the MD direction and the TD direction become unbalanced and the thermal shapability of the sheet becomes poor.
In addition, transferring methods using a mirror face-having endless metal belt have been disclosed in, for example, JP-B 61-24977, 61-32572, JP-A
62-284719. (The terms "JP-A" and "JP-B" as used herein means an "unexamined published Japanese patent application" and an "examined Japanese patent publication", respectively. ) However, the transparency of the sheets to be produced by such methods is still unsatisfactory.
On the other hand, the present applicant has heretofore proposed various techniques for controlling crystallization of polypropylene resin sheets or films by rapidly cooling them, as the means of improving their transparency without stretching the sheets or films (for example, JP-B 62-41457, 62-10816, JP-A 62-42822, 60-236719) and has already put them into practical use.
Recently, further improvement in the quality of sheet products and also in the productivity of them has been desired. Given the situation, however, theconventional methods have various problems. For example, if the production speed is elevated more, the shear stress at the extrusion die increases to form a so-called shark skin on the surface of the sheet formed whereby the surface gloss of the sheet is lowered or, that is, the transparency thereof is lowered.
In addition, if the thickness of the sheet to be formed is 0.6 mm or more, the transparency thereof is rapidly lowered due to the limit of the thermal conductivity in the direction of the thickness of the sheet. Accordingly, in view of the obiect of improving the productivity, a method of producing resin sheets at a higher speed is desired. In addition, also desired is a method of producing thick and highly-transparent resin sheets.
For these, the present applicant has already proposed a method for improving the transparency of a resin sheet, using an endless metal belt that was mirror-finished to have a surface roughness of 1.5 ~ m or less for treating a resin sheet, in which a particular resin material composition is used so as to inhibit the crystallization of the sheet to be formed therefrom while the both surfaces of the sheet formed are made glossy with the belt, as the method for further improving the prior art techniques (Japanese Patent Application No.
4-27485).
However, the method still had various problems. When the temperatures of the roll and the belt used in the method are low, the sheet formed is often banked so that the outward appearance of the sheet becomes bad. rapid cooling ofthe sheet formed is impossible~ and much time is needed for producing a thin sheet.
SU~ ARY OF T~E IM ~ TION
The present invention is to overcome the above-mentioned problems in the prior art techniques and to provide a method for efficiently producing a thermoplastic resin sheet or film having a high surface gloss, a high surface smoothness and a high transparencY.
0 Firstly,the present invention provides a method for producing a thermoplastic resin sheet or film. wherein a raw resin material to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin and an organic peroxide is melted under heat to form a resin sheet or film, the resulting resin sheet or film is brought into contact with and adhered to the outer surface of a cooling roll having a mirror-finishedsurface or the outer surface of an endless 0etal belt having a mirror-finished surface and then moved along with the roll or the belt. and thereafter it is inserted, pressed and cooled between the outer surface of the cooling roll and 2n the outer surface of the endless metal belt.
Secondly, the present invention provides a method for producing a thermoplastic resin sheet or film, wherein a raw resin material to which have been added one or more additives selected from the group consisting of a nucleatinq agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline polypropylenic copolymer is melted under heat to form a resin sheet or film, the resulting resin sheet or film is inserted into the intermediate between a cooling roll having a mirror-finished surface and an endless metal belt having a mirror-finished surface, then it is moved and cooled while being kept in contact with the outer surface of said cooling roll between said cooling roll and said endless metal belt, and thereafter it is pressed from the inside of said endlessmetal belt, then it is released from the contact with said cooling roll, and it is further moved while being kept adhered to said endless metal belt and then peeled from the belt.
BRIEF EXPLANATION OF THE DRAWINGS
Fig. 1 is an explanatory view showing the first embodiment of the device to be used in carrying out the first method of the present invention.
Fig. 2 is an explanatory view showing the second embodiment of the device to be used in carrying out the first method of the present invention.
Fig. 3 is an explanatory view showing the third embodiment of the device to be used in carrying out the first method of the present invention.
Fig. 4 is an explanatory view showing the fourth embodiment of the device to be used in carrying out the first method of the present invention.
Fig. 5 is an explanatory view showing the device used in Comparative Examples 3 and 4.
In these drawings, 1 is an extruder, 2 is a T-die, 3 is a sheet or film, 4 is an outer cooling roll, 5 is an endless metal belt, 6 is a pressure roll, 7 is a first inner cooling roll, 8 is an auxiliary inner cooling roll, 9 is a second inner cooling roll, 10 is an auxiliary outer cooling roll, 11 is an inner pressure device, 12 is a planet roll, 21 is an extruder, 22 is a T-die, 23is a sheet or film, 24 is an endless metal belt, 25A and 25B are cooling rolls, 26 is an auxiliary roll.
Fig. 6 is an exPlanatory view showing the first embodiment of the device to be used in carrying out the second method of the present invention.
Fig. 7 is an explanatory view showing the second embodiment of the device to be used in carrying out the second method of the present invention.
Fig. 8 is an exPlanatory view showing the third embodiment of the device to be used in carrying out the second method of the present invention.
Fig. 9 is an exPlanatory view showing the device used in Comparative Examples 7 and 8.
In these drawings, 31 is an extruder, 32 is a T-die, 33 is a sheet or film, 34 is an outer cooling roll, 35 is an endless metal belt, 36 is an inner cooling roll, 37 is a inner cooling pressure roll, 38 is an auxiliary inner cooling roll, 39 is an auxiliary outer cooling roll, 40 is a hydraulic pressure device, 41 is a planet roll, 42 is an extruder, 43 is a T-die, 44 is a sheet or film, 45 is an endless metal belt, 46A and 46B are cooling rolls, and 47 is an auxiliary roll.
DETAILED DESCRIPTION OF THE INVENTION
The thermoplastic resin to be used in the present invention as the essential raw material for the sheet or film is not specifically defined but may be not only a crystalline resin such as polypropylene, polyethylene, polyethylene terephthalate and so on but also a non-crystalline (amorphous) resin such as polystyrene, polycarbonate, polyvinyl chloride, polymethyl methacrylate and so on. Of these, however, preferred are crYstalline resins, especially polypropylenic resins (including propylene homopolymer, crystalline propylenic copolYmers comprising one or more comonomers, and their mixtures).
The sheet or film of the present invention includes not only a single-layered sheet or film but also a multi-layered (laminate) sheet or film.
In particular, in the first method of the present invention, the polypropylene resin preferably used as the essential raw material for the sheet or film is not specifically defined, including, for example, propylene homopolymer, polypropylenic random copolymers, polypropylenic block copolymers, etc. Such may be used singly or as a mixture of two or more of them.
According to the first method of the present invention, a raw material resin comprising a thermoplastic resin such as that mentioned above, to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin and an organic peroxide, is filmed through a T-die or the like.
According to the second method of the present invention, a raw material resin comprising a thermoplastic resin such as that mentioned above. to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline polypropylenic copolymer is filmed through a T-die or the like.
The nucleating agent to be employed in the present invention comprises one or more chosen from among talc, organic carboxylic acids and their metal salts, metal salts of organic phosphoric acids, polyvinylcycloalkanes, and dibenzylidene sorbitol derivatives of the qeneral for~ula (1):
(R)n ~$ ( I ) OH
HO~
wherein R represents one of an alkyl group having from l to 8 carbon atoms, a halogen atom and an alkoxY group having from t to 4 carbon atoms, and plural R's in the formula, if any, may be the same or different ones, and m and n each represent an integer of from O to 3.
According to the present invention, the nucleating agent may be added to the thermoplastic resin in an amount of from 0.5 to 10000 ppm by weight, preferably from lOO to 4000 ppm by weight, relative to the resin. If the 0 proportion of the nucleating agent is less than 0.5 ppm by wei~ht, the transparency of the resin sheet or film to be produced by the invention will be unsatisfactory. However, if it is more than lOOOO ppm by weight, the agent will bleed out to the surface of the resin sheet or film. Such are unfavorable.
As the high melting point polymer for use in the present invention, mentioned are, for example, high melting point polymers having a melting point of 200~ C or higher, such as polycarbonates, nylons, etc. The present invention employs fine powder (having a particle size of l ~ m or less) of such f ~ 8 a high melting point polymer.
According to the present invention, the fine powder of such a high melting point polymer may be added to the thermoplastic resin in an amount of from 0.5 to 10000 ppm by weight, preferably from 100 to 4000 ppm by weight, relative to the resin. If the proportion of the fine powder is less than 0.5 ppm by weight, the transparency of the resin sheet or film to be produced by the invention will be unsatisfactory. However, if it is more than 10000 ppm byweight, the sheet or film will be cloudy to lower its transparency. Such are unfavorable.
As the petroleum resin, for example, employable in the present invention is an aliphatic petroleum resin having a molecular weight of from 500 to 5000 and a softening point of from 50 to 170~ C. In place of the petroleum resin, also usable is a terpene resin.
According to the present invention, the petroleum resin or terpene resin may be added to the thermoplastic resin in an amount of from 3 to 30 % by weight, preferably from 5 to 15 % by weight, relative to the resin. If the proportion of the petroleum resin or terpene resin is less than 3 % by weight, its effect for improving the transParency of the resin sheet or film to be produced by the present invention will be unsatisfactory. However, if it is more than 30 % by weight, the sheet or film will be brittle. Such are unfavorable.
The present invention may also employ an organic peroxide as the additive. In this case, the thermoplastic resin such as that mentioned above is decomposed under heat in the presence of the organic peroxide and the thus-obtained, decomposed thermoplastic resin is used as the raw resin material.
The organic peroxide employable in the present invention is not specifically defined but it must be handled with ease in industrial operation and must be effective. For instance, preferred are organic peroxides having a half-life period of 0.5 minutes or longer at 150 ~ C.
As specific examples of such organic peroxides, mentioned are, for example, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane,t-butylperoxy-isopropyl carbonate, t-butylperoxy-3,3,5-trimethylhexanoate, 1,3-bis(2-t-butylperoxyisopropyl)benzene, etc.
The amount of the organic peroxide to be added to the raw resin material may be determined suitably, considering the melt indices (Ml) of the starting raw material and the intended resin composition, the decomposition temperature and time of the organic peroxide, etc. The thermal decomposition of the thermoplastic resin, using the organic peroxide such as that mentioned above, may be carried out by any known method. For instance, a mixture prepared by mixing the thermoplastic resin and the organic peroxide may be heated, using a Bumbury's mixer, a roll, an extruder, etc. Above all, a continuous extruder is preferably used for this purpose.
In the second method of the present invention, also usable as the additive is a crystalline polypropylenic copolymer.
The crystalline polypropylenic coPolymer may be anyone of random copolymers, block copolymers and grafted copolymers. In view of the economical aspect, preferred are random copolymers and block copolymers.
As random copolymers, preferred are ~ -olefin-propylene random copolymers. Of these, especially preferred are ethylene-propylene random copolymers having Ml of 10 9/10 min or less and containing ethylene in an amount of from 1 to 20 X by weight.
If the ethylene content in these ethylene-propylene random copolymers is less than 1 % by weight, their effect of improving the transparency of the shaped products will be in vain, but if it is more than 20 X by weight, the crystallinity of the resulting copolymers will be insufficient so that their effect of improving the transParency of the shaped products will be lowered.
Such are unfavorable.
As block copolymers, preferred are ~ -olefin-propylene block copolymers. Of these, especially preferred are ethylene-propylene block copolymers having Ml of 10 9/10 min or less and containing ethylene in an amount of from 1 to 40 X by weight.
If the ethylene content in these ethylene-propylene random copolymers is less than 1 % by weight, their effect of improving the transparency of the shaped products will be in vain, but if it is more than 40 X by weight, the whiteness of the shaped products will be remarkable. Such are unfavorable.
It is sufficient that one of the above-mentioned crystalline polypropylenic copolymers is added to the raw resin material of the present invention, but two or more of them may also be added thereto. In particular. a combination of the random copolymer and the block coPolymer is preferred, as it improves all the more the surface gloss and the transparency of the shaped products. Especially preferred is a combination of the ethylene-propylene random copolymer having Ml of 10 9/10 min or less and an ethylene content of from 1 to 20 X by weight and the ethylene-propylene block copolymer having Ml of10 9/10 min or less and an ethylene content of from 1 to 40 X by weight.
The crystalline polypropylenic copolymer may be added to the thermoplastic resin in an amount of from 0.2 to 40 parts by weight, preferably from 1.0 to 30 parts by weight, relative to 100 parts by weight of the resin.
If the proportion of the crystalline polypropylenic copolymer is less than 0.2 parts by weight, its effect of reducing the size of spherical crystalsformed in the sheet or film produced bY the present invention will be lowered sothat its effect of improving the transParenCY of the shaped products will be in vain. On the other hand, if it is more than 40 parts by weight, the shaped products will become gradually more whitish or will become uneven due to the uneven kneading of the raw resin material composition. Such are unfavorable.
In particular, if the proportion of the crystalline polypropylenic copolymer isfrom 1.0 to 30 parts by weight, its effect of improving the transparency of theshaped products is favorably great.
According to the present invention, the raw resin material composition comprising a thermoplastic resin to which have been added one or more of the above-mentioned additives is melted under heat to form a resin sheet or film.
The formation of the resin sheet or film may be carried out by any known method. In general, a T-die method, a calender roll method and the like are employed. Of these, a T-die method is preferred in view of the easiness of its operation. More concretely, for examPle, using a T-die extruder, the above-mentioned raw resin material comPosition is melted and kneaded under heat at temperatures of from 200 to 280~ C, and the resulting resin melt is extruded through the T-die to form a resin sheet or film.
According to the present invention, even a thick sheet or film having a thickness of more than 0.6 mm and having a relatively high transparency may be obtained. However, the thickness of the sheet or film to be obtained bY the -present invention is preferably 1 mm or less. If the thickness of the sheet orfilm is more than 1 mm, its internal haze will be increased due to its thickness so that its transParencY will be lowered unfavorably, though its surface gloss is still goo~. me thich~ess is preferably 0.1 mn or ~re.
In the sheet or film thus obtained in the manner mentioned above, the scattering of light in its inside is relatively small or, that is, its internalhaze is relatively small due to the intrinsic properties of the raw resin material, and therefore the transparency of the sheet or film is high.
According to the present invention, however, the sheet or film is cooled and lo subiected to treatment for increasing its surface gloss in the manner mentioned below, to thereby improve more its transparency.
Now, the first method of the present invention will be explained hereunder, with reference to the drawings. Fig. 1 is an explanatory view showing the first embodiment of the device to be used in carrying out the first method of the present invention. Fig. 2 is an explanatory view showing the second embodiment of the device to be used in carrying out the first method of the present invention. Fig. 3 is an explanatory view showing the third embodiment of the device to be used in carrying out the first method of the present invention. Fig. 4 is an exPlanatory view showing the fourth embodiment of the device to be used in carrying out the first method of the present invention.
Precisely, a raw resin material composition such as that mentioned above is put in an extruder 1, and the resulting resin melt is extruded while hot through a T-die 2 and filmed to obtain a sheet or film 3 (a sheet or film from the resin melt).
Next, the sheet or film 3 is directly brought into contact with and adhered to the outer surface of a cooling roli 4 having a mirror-finished surface, as shown in Fig. 1, or to the outer surface of an endless metal belt 5 having a mirror-finished surface, as shown in Fig. 2, optionally via a pressure roll 6 having a non-sticking surface.
When the sheet or film 3 is applied to the cooling roll 4 or the endless metal belt 5, if the adhesiveness of the former to the latter is not good (for example, if air exists between them), the sheet or film 3 will be unevenly glazed. In order to evade the problem, it is recommended to use the pressure roll 6 as mentioned above or to press the sheet or film 3 to the roll 4 or the belt 5 by pneumatic pressure in order to ensure the adhesion between them.
After the sheet or film 3 has been kept in contact with and adhered to the outer surface of the cooling roll 4 having a mirror-finished surface or the outer surface of the endless metal belt 5 having a mirror-finished surface, the former is inserted between the cooling roll 4 and the endless metal belt 5, moved under pressure and cooled while being kept in contact with the cooling roll 4 between the roll 4 and the belt 5.
In this process, in general, an endless metal belt made of a stainless steel, carbon steel or titanium alloy, preferably made of a stainless steel, isused as the belt 5.
The endless metal belt 5 to be used generally has a thickness of approximately from 0.4 to 1.0 mm. The endless metal belt 5 of this type is generally run at a relatively high speed of from 18 to 36 m/min.
The endless metal belt 5 shall have a mirror-finished surface having a surface roughness of 3.0 ~ m or less, preferably 1.0 ~ m or less, more preferably 0.5 ~ m or less.
The endless metal belt 5 is cooled with a first inner coolins roll 7 and a second inner cooling roll 9 or with these rolls and an auxiliary inner cooling roll 8 which is optionally provided in the device. The embodiments illustrated by Fig. 1 and Fig. 2 have the auxiliary inner cooling roll 8 along with the first inner cooling roll 7 and the second inner cooling-roll 9 all in the inside area of the endless metal belt 5.
On the other hand, the cooling roll 4 also shall have a mirror-finished surface, like the above-mentioned endless metal belt 5. It is desired that the cooling roll 4 has a large diameter, but in practical use, it is preferred thatthe diameter is approximately from 100 to 1000 mm.
The temperatures of the endless metal belt 5 and the cooling roll 4 generally fall within the range of from 10 to 90~ C. The lower the temperaturesof the endless metal belt 5 and the cooling roll 4, the higher the transparency of the shaped products (or the lower the internal haze thereof). However, if the temperatures are lower than 10~ C, the roll 4 or the belt 5 will be wet with due or banks will be formed to give bank marks to the surface of the shapedsheet or film 3 due to the rapid cooling. On the contrary, if the temperaturesare too high, the sheet or film 3 could not be cooled to solidification so that the transparency of the shaped products will be lowered.
Therefore, in the present invention, the temperatures of the endless metal belt 5 and the cooling roll 4 are generally within the range of from 10 to 90~ C, preferably from their dew points to 40~ C.
Regarding the temperatures of the cooling roll 4 and the endless metal belt 5, it is desired that the temperature of the endless metal belt 5 is made higher than that of the cooling roll 4, in order that the sheet or film 3 may be moved along with the belt 5 while being adhered thereto. In particular, it isrecommended that the temperature of the endless metal belt 5 is made higher thanthat of the cooling roll 4 by 5~ C or more, preferably 10~ C or more.
After the sheet or film 3 has been kept in contact with and adhered to the outer surface of the cooling roll 4 having a mirror-finished surface or to the outer surface of the endless metal belt 5, as mentioned above. it is inserted between the endless metal belt 5 and the cooling roll 4 (outer cooling roll) located outside the belt loop and moved therebetween under pressure while being kept in contact with the outer surface of the cooling roll 4, whereby the sheet or film 3 is cooled to a pre-determined temperature.
Afterwards, the sheet or film 3 is released from the contact with the cooling roll 4, then it is moved further while being kept adhered to the endlessmetal belt 5, and optionally after further cooled with a second auxiliarY inner cooling roll 9 or the like, it is peeled from the belt 5.
As mentioned above, the sheet or film 3 is sandwiched under pressure and cooled between the cooling roll 4 and the endless metal belt 5 for a pre-determined period of time (or in a pre-determined area).
The contact area where the sheet or film 3 is kept sandwiched under pressure between the roll and the belt is difficult to indiscriminately determine, since it varies, depending on the take-up speed and the thickness of the sheet or film 3, the temperatures of the belt and the roll and other conditions. In terms of time, in general, it may be for about one second. It is necessary that the sheet or film 3 is cooled to such a temperature that no sPherical crystals are formed in the sheet or film 3, at the end point of the contact area or at the outlet from the cooling roll 4.
The pressure to be imparted to the sheet or film 3 between the cooling roll 4 and the endless metal belt 5 is from 1 to 20 kg/cm2, preferably from 1 to 10 kg/cm2, in terms of a plane pressure. If the pressure is too small, a sheet or film having good transparency and surface gloss cannot be obtained. Onthe contrary, if it is too large, the sheet or film will be unfavorably oriented or wrinkled.
As the means for imparting the pressure to the sheet or film 3, an inner hydraulic pressure device 11 may be employed as shown in Fig. 3, or planet rolls 12 may be employed as shown in Fig. 4. It is desired that these are alsocooled. The embodiments illustrated by Fig. 3 and Fig. 4 are such that the inner pressure device 11 or the planet rolls 12 is/are applied to the sheet or film 3 that has been kept in contact with and adhered to the outer surface of the cooling roll 4 having a mirror-finished roll 4, like in Fig. 1, but these are not limitative. Apart from these, the device 11 or rolls 12 may be applied to the sheet or film 3 that has been kept in contact with and adhered to the outer surface of the endless metal belt 5 having a mirror-finished surface. Iike in Fig. 2.
After the sheet or film 3 has been cooled in the manner mentioned above, it is wound up around a take-up roll (not shown) to be a final product.
Next, the second method of the present invention will be explained, with reference to the drawings. Fig. 6 is an explanatory view showing the first embodiment of the device to be used in carrying out the second method of the present invention. Fig. 7 is an explanatory view showing the second embodiment of the device to be used in carrying out the second method of the present invention. Fig. 8 is an explanatory view showing the third embodiment of the device to be used in carrying out the second method of the present invention.
Precisely, a raw resin material composition such as that mentioned above is put in an extruder 31, and the resulting resin melt is extruded while hot through a T-die 32 and filmed to obtain a sheet or film 33 (a sheet of film fromthe resin melt).
Next, the sheet or film 33 is directly introduced between the outer surface of a cooling roll 34 having a mirror-finished surface and the outer surface of an endless metal belt 35 having a mirror-finished surface.
According to the second method of the present invention, the sheet or film 33 is introduced between the outer surface of the cooling roll 34 having a mirror-finished surface and the outer surface of the endless metal belt 35 having a mirror-finished surface. as mentioned above, and the thus-introduced sheet or film 33 is moved and cooled whiie being kept in contact with the outer surface of the cooling roll 34 between the cooling roll 34 and the endless metal belt 35 (or while being sandwiched therebetween).
More concretely, the sheet or film 33 is introduced into the intermediate between the endless metal belt 35 and the cooling roll 34 located outside the belt loop, then it is moved along the outer surface of the cooling roll 34 between the cooling roll 34 and the endless metal belt 35. In addition, while being moved, it is cooled.
For the introduction of the sheet or film 33, if it is first brought into contact with either of the cooling roll 34 and the endless metal belt 35, the sheet or film 33 will be frequently wrinkled. For the reason, it is desired that the sheet or film 33 is introduced into the intermediate part (almost the center part) of the area in which the cooling roll and the endless metal belt are kept in contact with each other.
In this process, in general, an endless metal belt made of a stainless steel, carbon steel or titanium alloY, preferably made of a stainless steel, isused as the belt 35.
The endless metal belt 35 to be used generally has a thickness of approximately from 0.4 to 1.0 mm. The endless metal belt 35 of this type is generally run at a relatively high speed of from 18 to 36 m/min.
The endless metal belt 35 shall have a mirror-finished surface having a surface roughness of 1.5 ~ m or less, preferably 0.2 ~ m or less, more preferably 0.05 ~ m or less.
The endless metal belt 35 is cooled with an inner cooling roll 36 or with the inner cooling roll 36 and an inner cooling pressure roll 37 (if desired, these rolls may have an additional function for driving the belt 35).
An auxiliary inner cooling roll 38 is located in the inside of the endless metalbelt 35. as will be mentioned hereinafter.
The cooling roll 34 shall have a mirror-finished surface, like the endless metal belt 35. The cooling roll 34 is desired to have a large diameter, but in practical use, it is preferred that its diameter is approximately from 100 to 1000 mm.
The temperatures of the endless metal belt 35 and the cooling roll 34 senerally fall within the range of from 10 to 50~ C. The lower the temperaturesof the endless metal belt 35 and the cooling roll 34, the higher the transparency of the shaped products (or the lower the internal haze thereof).
However, if the temperatures are lower than 10~ C, the roll 34 or the belt 35 will be wet with due or banks will be formed to give bank marks to the surface of the shaped sheet or film 33 due to the rapid cooling. On the contrary, if the temperatures are too high, the sheet or film 33 could not be cooled to solidification so that the transparency of the shaped products will be lowered.
Therefore, in the present invention, the temperatures of the endless metal belt 35 and the cooling roll 34 are generally within the range of from 10 to 50~ C, preferably from their dew points to 40~ C.
Regarding the temperatures of the cooling roll 34 and the endless metal belt 35, it is desired that the temperature of the endless metal belt 35 is made higher than that of the cooling roll 34, in order that the sheet or film 33 maybe moved along with the belt 35 while being adhered thereto. In particular, itis recommended that the temperature of the endless metal belt 35 is made higher than that of the cooling roll 34 by 5~ C or more, preferably 10~ C or more.
As mentioned above, the sheet or film 33 is introduced into the intermediate between the endless metal belt 35 and the cooling roll 34 (inner cooling roll) located outside the belt loop, and then it is moved along the outer surface of the cooling roll 34 between the cooling roll 34 and the endlessmetal belt 35. During the movement, the sheet or film 33 is cooled to a pre-determined temperature.
Next, the sheet or film 33 is pressed from the inside of the endless metal belt 35, using an inner cooling pressure roll 37, then it is released from the contact with the cooling roll 34 and moved while being adhered to the endless metal belt 35, and optionallY after further cooled with an auxiliary inner cooling roll 38 or the like, it is peeled from the belt 35.
According to the present invention, it is necessary that the pressure is imparted to the sheet or film 33 by the inner cooling pressure roll 37, after the sheet or film 33 has been introduced into the intermediate between the endless metal belt 35 and the cooling roll 34 located outside the belt loop and then moved along the outer surface of the cooling roll 34 between the cooling roll 34 and the endless metal belt 35. In other words, it is necessary that the inner cooling pressure roll 37 is located in the downstream after the cooling roll 34.
If the inner cooling pressure roll 37 is not located in the downstream after the cooling roll 34 or, for example, if the inner cooling pressure roll 37 is located almost at the same position as the cooling roll 34 to face to the latter via the endless metal belt 35 in the inside of the belt loop, the sheet or film 33 is to be pressed by the pressure roll 37 almost at the same time whenit is introduced between the roll 34 and the belt 35 so that the sheet or film 33 is inevitably wrinkled. Such is unfavorable. In order to prevent the sheetor film 33 from being wrinkled, the tension of the sheet or film 33 may be increased. In the case, however, the sheet or film 33 will be oriented.
It is again to be noted that, according to the second method of the present invention, the point at which the endless metal belt 35 is pushed by theinner cooling pressure roll 37 must indispensably be positioned later than the point at which the cooling roll 34 is first brought into contact with the endless metal belt 35. The point at which the endless metal belt 35 is pushed by the inner cooling pressure roll 37 cannot be determined indiscriminately, as varying depending on the speed and the temperature of the sheet or film 33 being treated.
As mentioned above, the sheet or film 33 is pressed by the inner cooling pressure roll 37, after it has been sandwiched under pressure and cooled between the cooling roll 34 and the endless metal belt 35 for a pre-determined period of time (or in a pre-determined area) and, as a result, the both surfaces of the sheet or film 33 are compressed by the cooling roll 34 and the endless metal belt 35 pushed by the inner pressure roll 37.
The contact area where the sheet or film 33 is kept sandwiched under pressure between the roll and the belt is difficult to indiscriminately determine, since it varies, depending on the take-up speed and the thickness of the sheet or film 33, the temperatures of the belt and the roll and other conditions. In general terms, it may be approximately from 10 to 300 mm. Itis necessary that the sheet or film 33 is cooled to such a temperature that no spherical crystals are formed in the sheet or film 33, at the end point of the contact area or at the outlet from the cooling roll 34.
The endless metal belt 35 is pushed to the cooling roll 34 by the inner cooling pressure roll 37 located inside the belt loop, so that the sheet or film33 that has been introduced between them is pressed by the cooling roll 34 and the endless metal belt 35.
The pressure to be yielded by the inner cooling pressure roll 37 may be from 5 to 50 kgtcm, preferably from 20 to 40 kg/cm in terms of a line pressure, or may be from 5 to 30 kg/cm2, preferably from 10 to 20 kg/cm2 in terms of a plane pressure. If the pressure is too small, a sheet or film having good transparency and surface gloss cannot be obtained. On the contrary, if it is too large, the sheet or film will be oriented or a large-scale device will be needed for the process. Such are unfavorable.
As mentioned above, the inner cooling pressure roll 37 pushes the endless metal belt 35 from its inside whereby the sheet or film 33 is pressed between the cooling roll 34 and the endless metal belt 35. Next, the thus-pressed sheet or film 33 is released from the contact with the cooling roll 34 and then moved along with the endless metal belt 35 while being adhered thereto.and thereafter it is generally cooled with an auxiliary inner cooling rol-l 38 and an auxiliary outer cooling roll 39. After thus cooled, the sheet or film 33 is released from the endless metal belt 35. If not cooled with the rolls 38and 39, the surface of the sheet or film 33 will be roughened by its peeling from the belt 35.
As the auxiliary cooling rolls, in general, used are the auxiliary inner cooling roll 38 and the auxiliary outer cooling roll 39. If desired, however, any one of these may be omitted. Anyhow, in this case, endless metal belt 35 shall be cooled to have a temperature falling within the range of from 10 to 50 ~ C with cooling roll(s).
In this process, the sheet or film 33 is released from the contact with the cooling roll 34, after having been treated under pressure, it is desired that the direction of the released sheet or film 33 is towards the belt (or towards the endless metal belt 35). Namely, the sheet or film 33 shall be cooled to its softening temperature or lower while it is flat. If not, a flat sheet or film could not be obtained due to the uneven cooling. If the treated sheet or film adheres to the cooling roll 34, it is impossible to uniformly coolthesheetor film.
After cooled, the sheet or film 33 is wound up around a take-up roll (not shown) to be a final product. Before the winding, the sheet or film 33 may be annealed, using a heating roll or the like. By such annealing, curling of the treated sheet or film 33 may be prevented effectively. In this case, the annealing temperature may be generally from 80 to 130~ C, preferably from 110 to 130~ C, though varying dePendins on the material of the sheet or fiim.
The embodiment illustrated above employs the inner cooling pressure roll 37.
Alternatively, an inner hydraulic pressure device 40 may be employed, as shown in Fig. 7, or planet rolls 41 may also be employed, as shown in Fig. 8.
It is desired that these are also cooled.
The present invention will be explained in more detail by means of the following examples, which, however, are not intended to restrict the scope of the present invention.
EXAMPLES 1 TO 4:
Using the device as shown in Fig. 1, an super-transparent thermoplastic resin sheet was produced.
First, a raw resin material composition prepared by adding 2000 ppm of DBS (1, 3-, 2, 4-dibenzylidene-sorbitol) (trade name: Gelall MD, produced by Shin-Nippon Rikagaku KK) as the nucleating agent to 100 parts by weight of propylene homopolymer (having a density of 0.91 g/cm3, a melt index of 2.0 9/10 min) (Idemitsu Polypro F-205S) was heated, melted and plasticized in the T-die extruder 1 (diameter of the extruder = 90 mm; L/D = 32; width of the die = 500 mm; distance between the die lips = 1 mm) at resin temperature of 280 ~ C, and then extruded through the T-die 2.
The thus-extruded sheet or film 3 (sheet or film from the resin melt) was brought into contact with and adhered to the cooling roll 4 (having a mirror-finished, hard chromium surface with a surface roughness of 0.2 ~ m), using the pressure roll 6, then directly introduced into the intermediate between the endless metal belt 5 (mirror-finished, endless stainless steel belt having a thickness of 0.4 mm and a surface roughness of 0.2 ~ m) and the coolingroll 4, moved, while kept in contact with the outer surface of the cooling roll 4 between the cooling roll 4 and the endless stainless belt 5. and pressed against the roll 4, while cooling the cooling roll 4 at the temperature indicated in Table 1 below. (The temperature of the inner cooling roll 7 was shown in Table 1 as the temperature of the endless metal belt 5.) The pressure imparted to the sheet or film 3 was calculated to be 1.5 kg/cm2, on the basis ofthe tension of the endless metal belt 5.
Afterwards, the thus-pressed sheet or film 3 was released from the contact with the cooling roll 4 (whereupon the direction of the released sheet or film was towards the belt), further moved while adhered to the endless metal belt 5, and then cooled with the second auxiliary inner cooling roll 9 and the auxiliary outer cooling roll 10 (both having a temperature of 30 ~ C) to obtain a polypropylene resin sheet having a thickness of 0.3 mm. The conditions for the operation and the results obtained are shown in Table 1. The filming speed was 20 m/min.
COMPARATIVE EXAMPLES 1 AND 2:
The same process as in ExamPles 1 to 4 was repeated under the conditions shown in Table 1, except that the nucleating agent was not used. The conditions for the operation and the results obtained are shown in Table 1.
COMPARATIVE EXAMPLES 3 AND 4:
The same process as in Examples 1 to 4 was repeated under the conditions shown in Table 1, except that the device of Fig. 5 (this is the same device as that described in Japanese Patent Application No. 4-27485) was employed.
More precisely, using the T-die extruder 21 (diameter of the extruder =
90 mm; L/D = 32; width of the die = 500 mm; distance between the die lips = 1 mm), the pre-determined, raw resin material composition was extruded through theT-die 22. The thus-extruded sheet or film 23 (sheet or film from the resin melt) was directly introduced between the facing two cooling rolls 25A and 25B
(both having a mirror-finished surface) between which stretched was the endless metal belt 24 (mirror-finished, endless stainless steel belt having a thickness of 0.6 mm and a surface roughness of 0.2 ~ m), while carried by the endless metal belt 24, to obtain a polypropylene resin sheet having a thickness of 0.3 mm. The conditions for the operation and the results obtained are shown in Table 1. In Fig. 5, 26 is an auxiliary roll.
~ - - 211 6389 Table 1 Device Additive Tempera- Tempera- Generation Treated Sheet Used ture of ture of of Belt Cooling Bank Marks (~C ) Roll Total Inside (~C ) Haze Haze Ex.1 Fig.1 Nucleating 25 20 No 3.8 2.8 Agent Ex. 2 Fig.1 Nucleating 30 25 No 4. 2 3.1 Agent Ex.3 Fig.1 Nucleating 35 30 No 5.6 3.5 Agent Ex.4 Fig.1 Nucleating 40 35 No 5.8 3.8 Agent Co. Fig.1 Not Used 20 10 No 10.8 9.5 Ex.1 Co. Fig.1 Not Used 25 17 No 12.4 11.2 Ex.2 Co. Fig.5 Not Used 20 20 No 12.1 11.5 Ex.3 Co. Fig. 5 Nucleating 25 20 Yes -- --Ex. 4 Agent EXAMPLES 5 TO 8:
Using the device of Fig. 6, a super-transparent thermoplastic resin sheet was produced.
First, a raw resin material composition prepared by adding 2000 ppm of DBS(1,3-2,4-dibenzylidene-sorbitol) (trade name: Gelall MD, produced by Shin-Nippon Rikagaku KK) as the nucleating agent to 100 parts by weight of propylene homopolymer (having a density of 0.91 g/cm3, a melt index of 2.0 9/10 min) (Idemitsu Polypro F-205S) was heated, melted and plasticized in the T-die extruder 31 (diameter of the extruder = 90 mm; L/D = 32; width of the die = 500 mm; distance between the die lips = 1 mm) at resin temperature of 280 ~ C, and then extruded through the T-die 32.
The thus-extruded sheet or film 33 (sheet or film from the resin melt) was directly introduced into the intermediate between the endless metal belt 35 (mirror-finished, endless stainless steel belt having a thickness of 0.4 mm and a surface roughness of 0.2 ~ m) and the cooling roll 34 (having a mirror-finished, hard chromium surface with a surface roughness of 0.2 ~ m), and then moved, while kept in contact with the outer surface of the cooling roll 34 between the cooling roll 34 and the endless stainless belt 35 and while cooling the cooling roll 34 at the temperature indicated in Table 2 below. (The temperature of the inner cooling roll 36 and the inner cooling pressure roll 37 was shown in Table 1 as the temperature of the endless metal belt 35.) Afterwards, the sheet or film 33 was pressed against the roll 34 under the pressure shown in Table 2, from the inside of the endless metal belt 35.
Next, the thus-pressed sheet or film 33 was released from the contact with the cooling roll 34 (whereupon the direction of the released sheet or film was towards the belt), further moved while adhered to the endless metal belt 35.and then cooled with the auxiliary inner cooling roll 38 and the auxiliary outer cooling roll 39 (both having a temperature of 30~ C) to obtain a polypropylene resin sheet having a thickness of 0.7 mm. The conditions for the operation and the results obtained are shown in Table 1. The filming speed was 15 m/min.
COMPARATIVE EXAMPLES 5 AND 6:
The same process as in ExamPles 5 to 8 was repeated under the conditions shown in Table 2, except that the nucleating agent was not used. The conditions for the operation and the results obtained are shown in Table 2.
COMPARATIVE EXAMPLES 7 AND 8:
The same process as in Examples 5 to 8 was repeated under the conditions shown in Table 2, except that the device of Fig. 6 (this is the same device as that described in Japanese Patent Application No. 4-27485) was employed.
More precisely, using the T-die extruder 42 (diameter of the extruder =
90 mm; L/D = 32; width of the die = 500 mm; distance between the die lips = 1 mm), the pre-determined, raw resin material composition was extruded through theT-die 43. The thus-extruded sheet or film 44 (sheet or film from the resin melt) was directly introduced between the facing two cooling rolls 46A and 46B
(both having a mirror-finished surface) between which stretched was the endless metal belt 45 (mirror-finished, endless stainless steel belt having a thickness of 0.4 mm and a surface roughness of 0.2 ~ m), while carried by the endless metal belt 45, to obtain a polypropylene resin sheet having a thickness of 0.7 mm. The conditions for the operation and the results obtained are shown in Table 2. In Fig. 9, 47 is an auxiliary roll.
Table 2 Device Additive Press- Tempera- Tempera- Generat- Treated Used ure ture of ture of ion of Sheet Impar- Belt Cooling Bank ed ( ~C ) Roll Marks Total Inside ~ ( ~C ) Haze Haze Ex.5 Fig.6 Nuclea- 25 25 8 No 15.6 11.6 ting Agent Ex.6 Fig.6 Nuclea- 25 30 14 No 15.9 11.7 ting Agent Ex.7 Fig.6 Nuclea- 25 35 22 No 18.1 12.9 ting Agent Ex.8 Fig.6 Nuclea- 25 40 28 No 19.8 14.3 ting Agent Co. Fig.6 Not Used 25 20 10 No 56.8 50.1 Ex.5 Co. Fig.6 Not Used 25 25 17 No 60.1 54.8 Ex.6 Co. Fig.9 Not Used 25 20 20 No 56.4 51.3 Ex.7 Co. Fig.9 Nuclea- 50 25 8 Yes - -Ex.8 ting Agent $ : kg/cm (as line pressure) According to the methods of the present invention that have been explained in detail hereinabove, a non-oriented thermoplastic resin sheet or film having high transparency and good surface gloss may be obtained efficiently, since the cooling temperature is low and the cooling speed is high.
The thermoPlastic resin sheet or film to be obtained by the present invention has high transparency and good surface gloss, even though being thick.Additionally, a high-transparent, thermoplastic resin sheet or film may be produced by the methods of the present invention, even though the filing speed is high.
Further, the methods of the present invention can be carried out, using simple and inexpensive devices.
Moreover, the thermoplastic resin sheet or film obtained by the methods of the present invention do not have any remarkable gels or fish eyes on its surface, and the thermoformability of the sheet or film is good.
Accordingly, the thermoplastic resin sheet or film obtained by the methods of the present invention is suitable for wrapping foods, medicines.
etc. In addition, it may also be applied to pneumatic shaping or thermal shaping.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
FIELD OF THE INVENTiON
The present invention relates to a method for efficiently producing a non-stretched, super-transparent sheet or film of a thermoplastic resin, which is favorable to wrapping materials for foods and medicines, etc.
PRIOR ART AND BACKGROUND OF THE INVENTION
Sheets or films made of crystalline thermoplastic resins, especially polypropylene resins, have different physical properties such as transparency, depending on the crystalline morphology thereof. Heretofore, the use of polypropylene resins has been limited though the resins have excellent physical properties such as heat resistance, moisture-proofness and oil resistance and they are lightweight and are cause no environmental pollution. This is because when the resins are shaped into sheets or further into containers from the shaped sheets, the sheets and the containers have poor transparency.
In order to make polypropylene resin sheets transparent, it is necessary to make the both surfaces of the sheet glossy and additionally to make the inside of the sheet transparent. To make the both surfaces of the sheet glossy,for example, there are known a method of transferring a roll mirror face to them, a method of transferring a metal mirror face to them using an endless belt having the face, a method of increasing the surface gloss of a melt web extruded from a die, etc. On the other hand, in order to make the inside of the sheet transparent, for example, there are known (a) a method of inhibiting crystallization of the sheet or letting the sheet have fine crystals (having a particle size smaller than the minimum wavelength of visible rays) by modifying the raw materials, (b) a method of inhibiting crystallization of the sheet by rapidly cooling it, (c) a method of breaking the crystals in the sheet by stretching or orientation, etc.
Accordingly, various methods comprised of these means as combined have heretofore been proposed. For instance, there has been proposed a method of transferring a roll mirror face to the surfaces of a resin sheet while a nucleating agent is added to the raw resin, whereby the both surfaces of the resin sheet are made glossy while the inside of the sheet is made transparent.
According to the method, however, it is difficult to form a thin sheet and the transparency of the sheet formed is not complete.
Apart from the above, another method has also been proposed, in which a roll mirror face is transferred to the both surfaces of a resin sheet while the sheet is rolled under pressure. According to the method, however, since the sheet is stretched and oriented by rolling under pressure, there occur various problems that the physical properties of the sheet in the MD direction and the TD direction become unbalanced and the thermal shapability of the sheet becomes poor.
In addition, transferring methods using a mirror face-having endless metal belt have been disclosed in, for example, JP-B 61-24977, 61-32572, JP-A
62-284719. (The terms "JP-A" and "JP-B" as used herein means an "unexamined published Japanese patent application" and an "examined Japanese patent publication", respectively. ) However, the transparency of the sheets to be produced by such methods is still unsatisfactory.
On the other hand, the present applicant has heretofore proposed various techniques for controlling crystallization of polypropylene resin sheets or films by rapidly cooling them, as the means of improving their transparency without stretching the sheets or films (for example, JP-B 62-41457, 62-10816, JP-A 62-42822, 60-236719) and has already put them into practical use.
Recently, further improvement in the quality of sheet products and also in the productivity of them has been desired. Given the situation, however, theconventional methods have various problems. For example, if the production speed is elevated more, the shear stress at the extrusion die increases to form a so-called shark skin on the surface of the sheet formed whereby the surface gloss of the sheet is lowered or, that is, the transparency thereof is lowered.
In addition, if the thickness of the sheet to be formed is 0.6 mm or more, the transparency thereof is rapidly lowered due to the limit of the thermal conductivity in the direction of the thickness of the sheet. Accordingly, in view of the obiect of improving the productivity, a method of producing resin sheets at a higher speed is desired. In addition, also desired is a method of producing thick and highly-transparent resin sheets.
For these, the present applicant has already proposed a method for improving the transparency of a resin sheet, using an endless metal belt that was mirror-finished to have a surface roughness of 1.5 ~ m or less for treating a resin sheet, in which a particular resin material composition is used so as to inhibit the crystallization of the sheet to be formed therefrom while the both surfaces of the sheet formed are made glossy with the belt, as the method for further improving the prior art techniques (Japanese Patent Application No.
4-27485).
However, the method still had various problems. When the temperatures of the roll and the belt used in the method are low, the sheet formed is often banked so that the outward appearance of the sheet becomes bad. rapid cooling ofthe sheet formed is impossible~ and much time is needed for producing a thin sheet.
SU~ ARY OF T~E IM ~ TION
The present invention is to overcome the above-mentioned problems in the prior art techniques and to provide a method for efficiently producing a thermoplastic resin sheet or film having a high surface gloss, a high surface smoothness and a high transparencY.
0 Firstly,the present invention provides a method for producing a thermoplastic resin sheet or film. wherein a raw resin material to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin and an organic peroxide is melted under heat to form a resin sheet or film, the resulting resin sheet or film is brought into contact with and adhered to the outer surface of a cooling roll having a mirror-finishedsurface or the outer surface of an endless 0etal belt having a mirror-finished surface and then moved along with the roll or the belt. and thereafter it is inserted, pressed and cooled between the outer surface of the cooling roll and 2n the outer surface of the endless metal belt.
Secondly, the present invention provides a method for producing a thermoplastic resin sheet or film, wherein a raw resin material to which have been added one or more additives selected from the group consisting of a nucleatinq agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline polypropylenic copolymer is melted under heat to form a resin sheet or film, the resulting resin sheet or film is inserted into the intermediate between a cooling roll having a mirror-finished surface and an endless metal belt having a mirror-finished surface, then it is moved and cooled while being kept in contact with the outer surface of said cooling roll between said cooling roll and said endless metal belt, and thereafter it is pressed from the inside of said endlessmetal belt, then it is released from the contact with said cooling roll, and it is further moved while being kept adhered to said endless metal belt and then peeled from the belt.
BRIEF EXPLANATION OF THE DRAWINGS
Fig. 1 is an explanatory view showing the first embodiment of the device to be used in carrying out the first method of the present invention.
Fig. 2 is an explanatory view showing the second embodiment of the device to be used in carrying out the first method of the present invention.
Fig. 3 is an explanatory view showing the third embodiment of the device to be used in carrying out the first method of the present invention.
Fig. 4 is an explanatory view showing the fourth embodiment of the device to be used in carrying out the first method of the present invention.
Fig. 5 is an explanatory view showing the device used in Comparative Examples 3 and 4.
In these drawings, 1 is an extruder, 2 is a T-die, 3 is a sheet or film, 4 is an outer cooling roll, 5 is an endless metal belt, 6 is a pressure roll, 7 is a first inner cooling roll, 8 is an auxiliary inner cooling roll, 9 is a second inner cooling roll, 10 is an auxiliary outer cooling roll, 11 is an inner pressure device, 12 is a planet roll, 21 is an extruder, 22 is a T-die, 23is a sheet or film, 24 is an endless metal belt, 25A and 25B are cooling rolls, 26 is an auxiliary roll.
Fig. 6 is an exPlanatory view showing the first embodiment of the device to be used in carrying out the second method of the present invention.
Fig. 7 is an explanatory view showing the second embodiment of the device to be used in carrying out the second method of the present invention.
Fig. 8 is an exPlanatory view showing the third embodiment of the device to be used in carrying out the second method of the present invention.
Fig. 9 is an exPlanatory view showing the device used in Comparative Examples 7 and 8.
In these drawings, 31 is an extruder, 32 is a T-die, 33 is a sheet or film, 34 is an outer cooling roll, 35 is an endless metal belt, 36 is an inner cooling roll, 37 is a inner cooling pressure roll, 38 is an auxiliary inner cooling roll, 39 is an auxiliary outer cooling roll, 40 is a hydraulic pressure device, 41 is a planet roll, 42 is an extruder, 43 is a T-die, 44 is a sheet or film, 45 is an endless metal belt, 46A and 46B are cooling rolls, and 47 is an auxiliary roll.
DETAILED DESCRIPTION OF THE INVENTION
The thermoplastic resin to be used in the present invention as the essential raw material for the sheet or film is not specifically defined but may be not only a crystalline resin such as polypropylene, polyethylene, polyethylene terephthalate and so on but also a non-crystalline (amorphous) resin such as polystyrene, polycarbonate, polyvinyl chloride, polymethyl methacrylate and so on. Of these, however, preferred are crYstalline resins, especially polypropylenic resins (including propylene homopolymer, crystalline propylenic copolYmers comprising one or more comonomers, and their mixtures).
The sheet or film of the present invention includes not only a single-layered sheet or film but also a multi-layered (laminate) sheet or film.
In particular, in the first method of the present invention, the polypropylene resin preferably used as the essential raw material for the sheet or film is not specifically defined, including, for example, propylene homopolymer, polypropylenic random copolymers, polypropylenic block copolymers, etc. Such may be used singly or as a mixture of two or more of them.
According to the first method of the present invention, a raw material resin comprising a thermoplastic resin such as that mentioned above, to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin and an organic peroxide, is filmed through a T-die or the like.
According to the second method of the present invention, a raw material resin comprising a thermoplastic resin such as that mentioned above. to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline polypropylenic copolymer is filmed through a T-die or the like.
The nucleating agent to be employed in the present invention comprises one or more chosen from among talc, organic carboxylic acids and their metal salts, metal salts of organic phosphoric acids, polyvinylcycloalkanes, and dibenzylidene sorbitol derivatives of the qeneral for~ula (1):
(R)n ~$ ( I ) OH
HO~
wherein R represents one of an alkyl group having from l to 8 carbon atoms, a halogen atom and an alkoxY group having from t to 4 carbon atoms, and plural R's in the formula, if any, may be the same or different ones, and m and n each represent an integer of from O to 3.
According to the present invention, the nucleating agent may be added to the thermoplastic resin in an amount of from 0.5 to 10000 ppm by weight, preferably from lOO to 4000 ppm by weight, relative to the resin. If the 0 proportion of the nucleating agent is less than 0.5 ppm by wei~ht, the transparency of the resin sheet or film to be produced by the invention will be unsatisfactory. However, if it is more than lOOOO ppm by weight, the agent will bleed out to the surface of the resin sheet or film. Such are unfavorable.
As the high melting point polymer for use in the present invention, mentioned are, for example, high melting point polymers having a melting point of 200~ C or higher, such as polycarbonates, nylons, etc. The present invention employs fine powder (having a particle size of l ~ m or less) of such f ~ 8 a high melting point polymer.
According to the present invention, the fine powder of such a high melting point polymer may be added to the thermoplastic resin in an amount of from 0.5 to 10000 ppm by weight, preferably from 100 to 4000 ppm by weight, relative to the resin. If the proportion of the fine powder is less than 0.5 ppm by weight, the transparency of the resin sheet or film to be produced by the invention will be unsatisfactory. However, if it is more than 10000 ppm byweight, the sheet or film will be cloudy to lower its transparency. Such are unfavorable.
As the petroleum resin, for example, employable in the present invention is an aliphatic petroleum resin having a molecular weight of from 500 to 5000 and a softening point of from 50 to 170~ C. In place of the petroleum resin, also usable is a terpene resin.
According to the present invention, the petroleum resin or terpene resin may be added to the thermoplastic resin in an amount of from 3 to 30 % by weight, preferably from 5 to 15 % by weight, relative to the resin. If the proportion of the petroleum resin or terpene resin is less than 3 % by weight, its effect for improving the transParency of the resin sheet or film to be produced by the present invention will be unsatisfactory. However, if it is more than 30 % by weight, the sheet or film will be brittle. Such are unfavorable.
The present invention may also employ an organic peroxide as the additive. In this case, the thermoplastic resin such as that mentioned above is decomposed under heat in the presence of the organic peroxide and the thus-obtained, decomposed thermoplastic resin is used as the raw resin material.
The organic peroxide employable in the present invention is not specifically defined but it must be handled with ease in industrial operation and must be effective. For instance, preferred are organic peroxides having a half-life period of 0.5 minutes or longer at 150 ~ C.
As specific examples of such organic peroxides, mentioned are, for example, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane,t-butylperoxy-isopropyl carbonate, t-butylperoxy-3,3,5-trimethylhexanoate, 1,3-bis(2-t-butylperoxyisopropyl)benzene, etc.
The amount of the organic peroxide to be added to the raw resin material may be determined suitably, considering the melt indices (Ml) of the starting raw material and the intended resin composition, the decomposition temperature and time of the organic peroxide, etc. The thermal decomposition of the thermoplastic resin, using the organic peroxide such as that mentioned above, may be carried out by any known method. For instance, a mixture prepared by mixing the thermoplastic resin and the organic peroxide may be heated, using a Bumbury's mixer, a roll, an extruder, etc. Above all, a continuous extruder is preferably used for this purpose.
In the second method of the present invention, also usable as the additive is a crystalline polypropylenic copolymer.
The crystalline polypropylenic coPolymer may be anyone of random copolymers, block copolymers and grafted copolymers. In view of the economical aspect, preferred are random copolymers and block copolymers.
As random copolymers, preferred are ~ -olefin-propylene random copolymers. Of these, especially preferred are ethylene-propylene random copolymers having Ml of 10 9/10 min or less and containing ethylene in an amount of from 1 to 20 X by weight.
If the ethylene content in these ethylene-propylene random copolymers is less than 1 % by weight, their effect of improving the transparency of the shaped products will be in vain, but if it is more than 20 X by weight, the crystallinity of the resulting copolymers will be insufficient so that their effect of improving the transParency of the shaped products will be lowered.
Such are unfavorable.
As block copolymers, preferred are ~ -olefin-propylene block copolymers. Of these, especially preferred are ethylene-propylene block copolymers having Ml of 10 9/10 min or less and containing ethylene in an amount of from 1 to 40 X by weight.
If the ethylene content in these ethylene-propylene random copolymers is less than 1 % by weight, their effect of improving the transparency of the shaped products will be in vain, but if it is more than 40 X by weight, the whiteness of the shaped products will be remarkable. Such are unfavorable.
It is sufficient that one of the above-mentioned crystalline polypropylenic copolymers is added to the raw resin material of the present invention, but two or more of them may also be added thereto. In particular. a combination of the random copolymer and the block coPolymer is preferred, as it improves all the more the surface gloss and the transparency of the shaped products. Especially preferred is a combination of the ethylene-propylene random copolymer having Ml of 10 9/10 min or less and an ethylene content of from 1 to 20 X by weight and the ethylene-propylene block copolymer having Ml of10 9/10 min or less and an ethylene content of from 1 to 40 X by weight.
The crystalline polypropylenic copolymer may be added to the thermoplastic resin in an amount of from 0.2 to 40 parts by weight, preferably from 1.0 to 30 parts by weight, relative to 100 parts by weight of the resin.
If the proportion of the crystalline polypropylenic copolymer is less than 0.2 parts by weight, its effect of reducing the size of spherical crystalsformed in the sheet or film produced bY the present invention will be lowered sothat its effect of improving the transParenCY of the shaped products will be in vain. On the other hand, if it is more than 40 parts by weight, the shaped products will become gradually more whitish or will become uneven due to the uneven kneading of the raw resin material composition. Such are unfavorable.
In particular, if the proportion of the crystalline polypropylenic copolymer isfrom 1.0 to 30 parts by weight, its effect of improving the transparency of theshaped products is favorably great.
According to the present invention, the raw resin material composition comprising a thermoplastic resin to which have been added one or more of the above-mentioned additives is melted under heat to form a resin sheet or film.
The formation of the resin sheet or film may be carried out by any known method. In general, a T-die method, a calender roll method and the like are employed. Of these, a T-die method is preferred in view of the easiness of its operation. More concretely, for examPle, using a T-die extruder, the above-mentioned raw resin material comPosition is melted and kneaded under heat at temperatures of from 200 to 280~ C, and the resulting resin melt is extruded through the T-die to form a resin sheet or film.
According to the present invention, even a thick sheet or film having a thickness of more than 0.6 mm and having a relatively high transparency may be obtained. However, the thickness of the sheet or film to be obtained bY the -present invention is preferably 1 mm or less. If the thickness of the sheet orfilm is more than 1 mm, its internal haze will be increased due to its thickness so that its transParencY will be lowered unfavorably, though its surface gloss is still goo~. me thich~ess is preferably 0.1 mn or ~re.
In the sheet or film thus obtained in the manner mentioned above, the scattering of light in its inside is relatively small or, that is, its internalhaze is relatively small due to the intrinsic properties of the raw resin material, and therefore the transparency of the sheet or film is high.
According to the present invention, however, the sheet or film is cooled and lo subiected to treatment for increasing its surface gloss in the manner mentioned below, to thereby improve more its transparency.
Now, the first method of the present invention will be explained hereunder, with reference to the drawings. Fig. 1 is an explanatory view showing the first embodiment of the device to be used in carrying out the first method of the present invention. Fig. 2 is an explanatory view showing the second embodiment of the device to be used in carrying out the first method of the present invention. Fig. 3 is an explanatory view showing the third embodiment of the device to be used in carrying out the first method of the present invention. Fig. 4 is an exPlanatory view showing the fourth embodiment of the device to be used in carrying out the first method of the present invention.
Precisely, a raw resin material composition such as that mentioned above is put in an extruder 1, and the resulting resin melt is extruded while hot through a T-die 2 and filmed to obtain a sheet or film 3 (a sheet or film from the resin melt).
Next, the sheet or film 3 is directly brought into contact with and adhered to the outer surface of a cooling roli 4 having a mirror-finished surface, as shown in Fig. 1, or to the outer surface of an endless metal belt 5 having a mirror-finished surface, as shown in Fig. 2, optionally via a pressure roll 6 having a non-sticking surface.
When the sheet or film 3 is applied to the cooling roll 4 or the endless metal belt 5, if the adhesiveness of the former to the latter is not good (for example, if air exists between them), the sheet or film 3 will be unevenly glazed. In order to evade the problem, it is recommended to use the pressure roll 6 as mentioned above or to press the sheet or film 3 to the roll 4 or the belt 5 by pneumatic pressure in order to ensure the adhesion between them.
After the sheet or film 3 has been kept in contact with and adhered to the outer surface of the cooling roll 4 having a mirror-finished surface or the outer surface of the endless metal belt 5 having a mirror-finished surface, the former is inserted between the cooling roll 4 and the endless metal belt 5, moved under pressure and cooled while being kept in contact with the cooling roll 4 between the roll 4 and the belt 5.
In this process, in general, an endless metal belt made of a stainless steel, carbon steel or titanium alloy, preferably made of a stainless steel, isused as the belt 5.
The endless metal belt 5 to be used generally has a thickness of approximately from 0.4 to 1.0 mm. The endless metal belt 5 of this type is generally run at a relatively high speed of from 18 to 36 m/min.
The endless metal belt 5 shall have a mirror-finished surface having a surface roughness of 3.0 ~ m or less, preferably 1.0 ~ m or less, more preferably 0.5 ~ m or less.
The endless metal belt 5 is cooled with a first inner coolins roll 7 and a second inner cooling roll 9 or with these rolls and an auxiliary inner cooling roll 8 which is optionally provided in the device. The embodiments illustrated by Fig. 1 and Fig. 2 have the auxiliary inner cooling roll 8 along with the first inner cooling roll 7 and the second inner cooling-roll 9 all in the inside area of the endless metal belt 5.
On the other hand, the cooling roll 4 also shall have a mirror-finished surface, like the above-mentioned endless metal belt 5. It is desired that the cooling roll 4 has a large diameter, but in practical use, it is preferred thatthe diameter is approximately from 100 to 1000 mm.
The temperatures of the endless metal belt 5 and the cooling roll 4 generally fall within the range of from 10 to 90~ C. The lower the temperaturesof the endless metal belt 5 and the cooling roll 4, the higher the transparency of the shaped products (or the lower the internal haze thereof). However, if the temperatures are lower than 10~ C, the roll 4 or the belt 5 will be wet with due or banks will be formed to give bank marks to the surface of the shapedsheet or film 3 due to the rapid cooling. On the contrary, if the temperaturesare too high, the sheet or film 3 could not be cooled to solidification so that the transparency of the shaped products will be lowered.
Therefore, in the present invention, the temperatures of the endless metal belt 5 and the cooling roll 4 are generally within the range of from 10 to 90~ C, preferably from their dew points to 40~ C.
Regarding the temperatures of the cooling roll 4 and the endless metal belt 5, it is desired that the temperature of the endless metal belt 5 is made higher than that of the cooling roll 4, in order that the sheet or film 3 may be moved along with the belt 5 while being adhered thereto. In particular, it isrecommended that the temperature of the endless metal belt 5 is made higher thanthat of the cooling roll 4 by 5~ C or more, preferably 10~ C or more.
After the sheet or film 3 has been kept in contact with and adhered to the outer surface of the cooling roll 4 having a mirror-finished surface or to the outer surface of the endless metal belt 5, as mentioned above. it is inserted between the endless metal belt 5 and the cooling roll 4 (outer cooling roll) located outside the belt loop and moved therebetween under pressure while being kept in contact with the outer surface of the cooling roll 4, whereby the sheet or film 3 is cooled to a pre-determined temperature.
Afterwards, the sheet or film 3 is released from the contact with the cooling roll 4, then it is moved further while being kept adhered to the endlessmetal belt 5, and optionally after further cooled with a second auxiliarY inner cooling roll 9 or the like, it is peeled from the belt 5.
As mentioned above, the sheet or film 3 is sandwiched under pressure and cooled between the cooling roll 4 and the endless metal belt 5 for a pre-determined period of time (or in a pre-determined area).
The contact area where the sheet or film 3 is kept sandwiched under pressure between the roll and the belt is difficult to indiscriminately determine, since it varies, depending on the take-up speed and the thickness of the sheet or film 3, the temperatures of the belt and the roll and other conditions. In terms of time, in general, it may be for about one second. It is necessary that the sheet or film 3 is cooled to such a temperature that no sPherical crystals are formed in the sheet or film 3, at the end point of the contact area or at the outlet from the cooling roll 4.
The pressure to be imparted to the sheet or film 3 between the cooling roll 4 and the endless metal belt 5 is from 1 to 20 kg/cm2, preferably from 1 to 10 kg/cm2, in terms of a plane pressure. If the pressure is too small, a sheet or film having good transparency and surface gloss cannot be obtained. Onthe contrary, if it is too large, the sheet or film will be unfavorably oriented or wrinkled.
As the means for imparting the pressure to the sheet or film 3, an inner hydraulic pressure device 11 may be employed as shown in Fig. 3, or planet rolls 12 may be employed as shown in Fig. 4. It is desired that these are alsocooled. The embodiments illustrated by Fig. 3 and Fig. 4 are such that the inner pressure device 11 or the planet rolls 12 is/are applied to the sheet or film 3 that has been kept in contact with and adhered to the outer surface of the cooling roll 4 having a mirror-finished roll 4, like in Fig. 1, but these are not limitative. Apart from these, the device 11 or rolls 12 may be applied to the sheet or film 3 that has been kept in contact with and adhered to the outer surface of the endless metal belt 5 having a mirror-finished surface. Iike in Fig. 2.
After the sheet or film 3 has been cooled in the manner mentioned above, it is wound up around a take-up roll (not shown) to be a final product.
Next, the second method of the present invention will be explained, with reference to the drawings. Fig. 6 is an explanatory view showing the first embodiment of the device to be used in carrying out the second method of the present invention. Fig. 7 is an explanatory view showing the second embodiment of the device to be used in carrying out the second method of the present invention. Fig. 8 is an explanatory view showing the third embodiment of the device to be used in carrying out the second method of the present invention.
Precisely, a raw resin material composition such as that mentioned above is put in an extruder 31, and the resulting resin melt is extruded while hot through a T-die 32 and filmed to obtain a sheet or film 33 (a sheet of film fromthe resin melt).
Next, the sheet or film 33 is directly introduced between the outer surface of a cooling roll 34 having a mirror-finished surface and the outer surface of an endless metal belt 35 having a mirror-finished surface.
According to the second method of the present invention, the sheet or film 33 is introduced between the outer surface of the cooling roll 34 having a mirror-finished surface and the outer surface of the endless metal belt 35 having a mirror-finished surface. as mentioned above, and the thus-introduced sheet or film 33 is moved and cooled whiie being kept in contact with the outer surface of the cooling roll 34 between the cooling roll 34 and the endless metal belt 35 (or while being sandwiched therebetween).
More concretely, the sheet or film 33 is introduced into the intermediate between the endless metal belt 35 and the cooling roll 34 located outside the belt loop, then it is moved along the outer surface of the cooling roll 34 between the cooling roll 34 and the endless metal belt 35. In addition, while being moved, it is cooled.
For the introduction of the sheet or film 33, if it is first brought into contact with either of the cooling roll 34 and the endless metal belt 35, the sheet or film 33 will be frequently wrinkled. For the reason, it is desired that the sheet or film 33 is introduced into the intermediate part (almost the center part) of the area in which the cooling roll and the endless metal belt are kept in contact with each other.
In this process, in general, an endless metal belt made of a stainless steel, carbon steel or titanium alloY, preferably made of a stainless steel, isused as the belt 35.
The endless metal belt 35 to be used generally has a thickness of approximately from 0.4 to 1.0 mm. The endless metal belt 35 of this type is generally run at a relatively high speed of from 18 to 36 m/min.
The endless metal belt 35 shall have a mirror-finished surface having a surface roughness of 1.5 ~ m or less, preferably 0.2 ~ m or less, more preferably 0.05 ~ m or less.
The endless metal belt 35 is cooled with an inner cooling roll 36 or with the inner cooling roll 36 and an inner cooling pressure roll 37 (if desired, these rolls may have an additional function for driving the belt 35).
An auxiliary inner cooling roll 38 is located in the inside of the endless metalbelt 35. as will be mentioned hereinafter.
The cooling roll 34 shall have a mirror-finished surface, like the endless metal belt 35. The cooling roll 34 is desired to have a large diameter, but in practical use, it is preferred that its diameter is approximately from 100 to 1000 mm.
The temperatures of the endless metal belt 35 and the cooling roll 34 senerally fall within the range of from 10 to 50~ C. The lower the temperaturesof the endless metal belt 35 and the cooling roll 34, the higher the transparency of the shaped products (or the lower the internal haze thereof).
However, if the temperatures are lower than 10~ C, the roll 34 or the belt 35 will be wet with due or banks will be formed to give bank marks to the surface of the shaped sheet or film 33 due to the rapid cooling. On the contrary, if the temperatures are too high, the sheet or film 33 could not be cooled to solidification so that the transparency of the shaped products will be lowered.
Therefore, in the present invention, the temperatures of the endless metal belt 35 and the cooling roll 34 are generally within the range of from 10 to 50~ C, preferably from their dew points to 40~ C.
Regarding the temperatures of the cooling roll 34 and the endless metal belt 35, it is desired that the temperature of the endless metal belt 35 is made higher than that of the cooling roll 34, in order that the sheet or film 33 maybe moved along with the belt 35 while being adhered thereto. In particular, itis recommended that the temperature of the endless metal belt 35 is made higher than that of the cooling roll 34 by 5~ C or more, preferably 10~ C or more.
As mentioned above, the sheet or film 33 is introduced into the intermediate between the endless metal belt 35 and the cooling roll 34 (inner cooling roll) located outside the belt loop, and then it is moved along the outer surface of the cooling roll 34 between the cooling roll 34 and the endlessmetal belt 35. During the movement, the sheet or film 33 is cooled to a pre-determined temperature.
Next, the sheet or film 33 is pressed from the inside of the endless metal belt 35, using an inner cooling pressure roll 37, then it is released from the contact with the cooling roll 34 and moved while being adhered to the endless metal belt 35, and optionallY after further cooled with an auxiliary inner cooling roll 38 or the like, it is peeled from the belt 35.
According to the present invention, it is necessary that the pressure is imparted to the sheet or film 33 by the inner cooling pressure roll 37, after the sheet or film 33 has been introduced into the intermediate between the endless metal belt 35 and the cooling roll 34 located outside the belt loop and then moved along the outer surface of the cooling roll 34 between the cooling roll 34 and the endless metal belt 35. In other words, it is necessary that the inner cooling pressure roll 37 is located in the downstream after the cooling roll 34.
If the inner cooling pressure roll 37 is not located in the downstream after the cooling roll 34 or, for example, if the inner cooling pressure roll 37 is located almost at the same position as the cooling roll 34 to face to the latter via the endless metal belt 35 in the inside of the belt loop, the sheet or film 33 is to be pressed by the pressure roll 37 almost at the same time whenit is introduced between the roll 34 and the belt 35 so that the sheet or film 33 is inevitably wrinkled. Such is unfavorable. In order to prevent the sheetor film 33 from being wrinkled, the tension of the sheet or film 33 may be increased. In the case, however, the sheet or film 33 will be oriented.
It is again to be noted that, according to the second method of the present invention, the point at which the endless metal belt 35 is pushed by theinner cooling pressure roll 37 must indispensably be positioned later than the point at which the cooling roll 34 is first brought into contact with the endless metal belt 35. The point at which the endless metal belt 35 is pushed by the inner cooling pressure roll 37 cannot be determined indiscriminately, as varying depending on the speed and the temperature of the sheet or film 33 being treated.
As mentioned above, the sheet or film 33 is pressed by the inner cooling pressure roll 37, after it has been sandwiched under pressure and cooled between the cooling roll 34 and the endless metal belt 35 for a pre-determined period of time (or in a pre-determined area) and, as a result, the both surfaces of the sheet or film 33 are compressed by the cooling roll 34 and the endless metal belt 35 pushed by the inner pressure roll 37.
The contact area where the sheet or film 33 is kept sandwiched under pressure between the roll and the belt is difficult to indiscriminately determine, since it varies, depending on the take-up speed and the thickness of the sheet or film 33, the temperatures of the belt and the roll and other conditions. In general terms, it may be approximately from 10 to 300 mm. Itis necessary that the sheet or film 33 is cooled to such a temperature that no spherical crystals are formed in the sheet or film 33, at the end point of the contact area or at the outlet from the cooling roll 34.
The endless metal belt 35 is pushed to the cooling roll 34 by the inner cooling pressure roll 37 located inside the belt loop, so that the sheet or film33 that has been introduced between them is pressed by the cooling roll 34 and the endless metal belt 35.
The pressure to be yielded by the inner cooling pressure roll 37 may be from 5 to 50 kgtcm, preferably from 20 to 40 kg/cm in terms of a line pressure, or may be from 5 to 30 kg/cm2, preferably from 10 to 20 kg/cm2 in terms of a plane pressure. If the pressure is too small, a sheet or film having good transparency and surface gloss cannot be obtained. On the contrary, if it is too large, the sheet or film will be oriented or a large-scale device will be needed for the process. Such are unfavorable.
As mentioned above, the inner cooling pressure roll 37 pushes the endless metal belt 35 from its inside whereby the sheet or film 33 is pressed between the cooling roll 34 and the endless metal belt 35. Next, the thus-pressed sheet or film 33 is released from the contact with the cooling roll 34 and then moved along with the endless metal belt 35 while being adhered thereto.and thereafter it is generally cooled with an auxiliary inner cooling rol-l 38 and an auxiliary outer cooling roll 39. After thus cooled, the sheet or film 33 is released from the endless metal belt 35. If not cooled with the rolls 38and 39, the surface of the sheet or film 33 will be roughened by its peeling from the belt 35.
As the auxiliary cooling rolls, in general, used are the auxiliary inner cooling roll 38 and the auxiliary outer cooling roll 39. If desired, however, any one of these may be omitted. Anyhow, in this case, endless metal belt 35 shall be cooled to have a temperature falling within the range of from 10 to 50 ~ C with cooling roll(s).
In this process, the sheet or film 33 is released from the contact with the cooling roll 34, after having been treated under pressure, it is desired that the direction of the released sheet or film 33 is towards the belt (or towards the endless metal belt 35). Namely, the sheet or film 33 shall be cooled to its softening temperature or lower while it is flat. If not, a flat sheet or film could not be obtained due to the uneven cooling. If the treated sheet or film adheres to the cooling roll 34, it is impossible to uniformly coolthesheetor film.
After cooled, the sheet or film 33 is wound up around a take-up roll (not shown) to be a final product. Before the winding, the sheet or film 33 may be annealed, using a heating roll or the like. By such annealing, curling of the treated sheet or film 33 may be prevented effectively. In this case, the annealing temperature may be generally from 80 to 130~ C, preferably from 110 to 130~ C, though varying dePendins on the material of the sheet or fiim.
The embodiment illustrated above employs the inner cooling pressure roll 37.
Alternatively, an inner hydraulic pressure device 40 may be employed, as shown in Fig. 7, or planet rolls 41 may also be employed, as shown in Fig. 8.
It is desired that these are also cooled.
The present invention will be explained in more detail by means of the following examples, which, however, are not intended to restrict the scope of the present invention.
EXAMPLES 1 TO 4:
Using the device as shown in Fig. 1, an super-transparent thermoplastic resin sheet was produced.
First, a raw resin material composition prepared by adding 2000 ppm of DBS (1, 3-, 2, 4-dibenzylidene-sorbitol) (trade name: Gelall MD, produced by Shin-Nippon Rikagaku KK) as the nucleating agent to 100 parts by weight of propylene homopolymer (having a density of 0.91 g/cm3, a melt index of 2.0 9/10 min) (Idemitsu Polypro F-205S) was heated, melted and plasticized in the T-die extruder 1 (diameter of the extruder = 90 mm; L/D = 32; width of the die = 500 mm; distance between the die lips = 1 mm) at resin temperature of 280 ~ C, and then extruded through the T-die 2.
The thus-extruded sheet or film 3 (sheet or film from the resin melt) was brought into contact with and adhered to the cooling roll 4 (having a mirror-finished, hard chromium surface with a surface roughness of 0.2 ~ m), using the pressure roll 6, then directly introduced into the intermediate between the endless metal belt 5 (mirror-finished, endless stainless steel belt having a thickness of 0.4 mm and a surface roughness of 0.2 ~ m) and the coolingroll 4, moved, while kept in contact with the outer surface of the cooling roll 4 between the cooling roll 4 and the endless stainless belt 5. and pressed against the roll 4, while cooling the cooling roll 4 at the temperature indicated in Table 1 below. (The temperature of the inner cooling roll 7 was shown in Table 1 as the temperature of the endless metal belt 5.) The pressure imparted to the sheet or film 3 was calculated to be 1.5 kg/cm2, on the basis ofthe tension of the endless metal belt 5.
Afterwards, the thus-pressed sheet or film 3 was released from the contact with the cooling roll 4 (whereupon the direction of the released sheet or film was towards the belt), further moved while adhered to the endless metal belt 5, and then cooled with the second auxiliary inner cooling roll 9 and the auxiliary outer cooling roll 10 (both having a temperature of 30 ~ C) to obtain a polypropylene resin sheet having a thickness of 0.3 mm. The conditions for the operation and the results obtained are shown in Table 1. The filming speed was 20 m/min.
COMPARATIVE EXAMPLES 1 AND 2:
The same process as in ExamPles 1 to 4 was repeated under the conditions shown in Table 1, except that the nucleating agent was not used. The conditions for the operation and the results obtained are shown in Table 1.
COMPARATIVE EXAMPLES 3 AND 4:
The same process as in Examples 1 to 4 was repeated under the conditions shown in Table 1, except that the device of Fig. 5 (this is the same device as that described in Japanese Patent Application No. 4-27485) was employed.
More precisely, using the T-die extruder 21 (diameter of the extruder =
90 mm; L/D = 32; width of the die = 500 mm; distance between the die lips = 1 mm), the pre-determined, raw resin material composition was extruded through theT-die 22. The thus-extruded sheet or film 23 (sheet or film from the resin melt) was directly introduced between the facing two cooling rolls 25A and 25B
(both having a mirror-finished surface) between which stretched was the endless metal belt 24 (mirror-finished, endless stainless steel belt having a thickness of 0.6 mm and a surface roughness of 0.2 ~ m), while carried by the endless metal belt 24, to obtain a polypropylene resin sheet having a thickness of 0.3 mm. The conditions for the operation and the results obtained are shown in Table 1. In Fig. 5, 26 is an auxiliary roll.
~ - - 211 6389 Table 1 Device Additive Tempera- Tempera- Generation Treated Sheet Used ture of ture of of Belt Cooling Bank Marks (~C ) Roll Total Inside (~C ) Haze Haze Ex.1 Fig.1 Nucleating 25 20 No 3.8 2.8 Agent Ex. 2 Fig.1 Nucleating 30 25 No 4. 2 3.1 Agent Ex.3 Fig.1 Nucleating 35 30 No 5.6 3.5 Agent Ex.4 Fig.1 Nucleating 40 35 No 5.8 3.8 Agent Co. Fig.1 Not Used 20 10 No 10.8 9.5 Ex.1 Co. Fig.1 Not Used 25 17 No 12.4 11.2 Ex.2 Co. Fig.5 Not Used 20 20 No 12.1 11.5 Ex.3 Co. Fig. 5 Nucleating 25 20 Yes -- --Ex. 4 Agent EXAMPLES 5 TO 8:
Using the device of Fig. 6, a super-transparent thermoplastic resin sheet was produced.
First, a raw resin material composition prepared by adding 2000 ppm of DBS(1,3-2,4-dibenzylidene-sorbitol) (trade name: Gelall MD, produced by Shin-Nippon Rikagaku KK) as the nucleating agent to 100 parts by weight of propylene homopolymer (having a density of 0.91 g/cm3, a melt index of 2.0 9/10 min) (Idemitsu Polypro F-205S) was heated, melted and plasticized in the T-die extruder 31 (diameter of the extruder = 90 mm; L/D = 32; width of the die = 500 mm; distance between the die lips = 1 mm) at resin temperature of 280 ~ C, and then extruded through the T-die 32.
The thus-extruded sheet or film 33 (sheet or film from the resin melt) was directly introduced into the intermediate between the endless metal belt 35 (mirror-finished, endless stainless steel belt having a thickness of 0.4 mm and a surface roughness of 0.2 ~ m) and the cooling roll 34 (having a mirror-finished, hard chromium surface with a surface roughness of 0.2 ~ m), and then moved, while kept in contact with the outer surface of the cooling roll 34 between the cooling roll 34 and the endless stainless belt 35 and while cooling the cooling roll 34 at the temperature indicated in Table 2 below. (The temperature of the inner cooling roll 36 and the inner cooling pressure roll 37 was shown in Table 1 as the temperature of the endless metal belt 35.) Afterwards, the sheet or film 33 was pressed against the roll 34 under the pressure shown in Table 2, from the inside of the endless metal belt 35.
Next, the thus-pressed sheet or film 33 was released from the contact with the cooling roll 34 (whereupon the direction of the released sheet or film was towards the belt), further moved while adhered to the endless metal belt 35.and then cooled with the auxiliary inner cooling roll 38 and the auxiliary outer cooling roll 39 (both having a temperature of 30~ C) to obtain a polypropylene resin sheet having a thickness of 0.7 mm. The conditions for the operation and the results obtained are shown in Table 1. The filming speed was 15 m/min.
COMPARATIVE EXAMPLES 5 AND 6:
The same process as in ExamPles 5 to 8 was repeated under the conditions shown in Table 2, except that the nucleating agent was not used. The conditions for the operation and the results obtained are shown in Table 2.
COMPARATIVE EXAMPLES 7 AND 8:
The same process as in Examples 5 to 8 was repeated under the conditions shown in Table 2, except that the device of Fig. 6 (this is the same device as that described in Japanese Patent Application No. 4-27485) was employed.
More precisely, using the T-die extruder 42 (diameter of the extruder =
90 mm; L/D = 32; width of the die = 500 mm; distance between the die lips = 1 mm), the pre-determined, raw resin material composition was extruded through theT-die 43. The thus-extruded sheet or film 44 (sheet or film from the resin melt) was directly introduced between the facing two cooling rolls 46A and 46B
(both having a mirror-finished surface) between which stretched was the endless metal belt 45 (mirror-finished, endless stainless steel belt having a thickness of 0.4 mm and a surface roughness of 0.2 ~ m), while carried by the endless metal belt 45, to obtain a polypropylene resin sheet having a thickness of 0.7 mm. The conditions for the operation and the results obtained are shown in Table 2. In Fig. 9, 47 is an auxiliary roll.
Table 2 Device Additive Press- Tempera- Tempera- Generat- Treated Used ure ture of ture of ion of Sheet Impar- Belt Cooling Bank ed ( ~C ) Roll Marks Total Inside ~ ( ~C ) Haze Haze Ex.5 Fig.6 Nuclea- 25 25 8 No 15.6 11.6 ting Agent Ex.6 Fig.6 Nuclea- 25 30 14 No 15.9 11.7 ting Agent Ex.7 Fig.6 Nuclea- 25 35 22 No 18.1 12.9 ting Agent Ex.8 Fig.6 Nuclea- 25 40 28 No 19.8 14.3 ting Agent Co. Fig.6 Not Used 25 20 10 No 56.8 50.1 Ex.5 Co. Fig.6 Not Used 25 25 17 No 60.1 54.8 Ex.6 Co. Fig.9 Not Used 25 20 20 No 56.4 51.3 Ex.7 Co. Fig.9 Nuclea- 50 25 8 Yes - -Ex.8 ting Agent $ : kg/cm (as line pressure) According to the methods of the present invention that have been explained in detail hereinabove, a non-oriented thermoplastic resin sheet or film having high transparency and good surface gloss may be obtained efficiently, since the cooling temperature is low and the cooling speed is high.
The thermoPlastic resin sheet or film to be obtained by the present invention has high transparency and good surface gloss, even though being thick.Additionally, a high-transparent, thermoplastic resin sheet or film may be produced by the methods of the present invention, even though the filing speed is high.
Further, the methods of the present invention can be carried out, using simple and inexpensive devices.
Moreover, the thermoplastic resin sheet or film obtained by the methods of the present invention do not have any remarkable gels or fish eyes on its surface, and the thermoformability of the sheet or film is good.
Accordingly, the thermoplastic resin sheet or film obtained by the methods of the present invention is suitable for wrapping foods, medicines.
etc. In addition, it may also be applied to pneumatic shaping or thermal shaping.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
Claims (19)
1. A method for producing a thermoplastic resin sheet or film, which comprises:
(a) melting under heat a raw resin material to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin and an organic peroxide to form a resin sheet or film, (b) bringing the resulting resin sheet or film into contact with and adhering it to a mirror-finished outer surface of a cooling roll or a mirror-finished outer surface of an endless metal belt and then moving the sheet or film along with the cooling roll or the endless metal belt, and (c) thereafter inserting, pressing and cooling the sheet or film between the outer surface of the cooling roll and the outer surface of the endless metal belt.
(a) melting under heat a raw resin material to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin and an organic peroxide to form a resin sheet or film, (b) bringing the resulting resin sheet or film into contact with and adhering it to a mirror-finished outer surface of a cooling roll or a mirror-finished outer surface of an endless metal belt and then moving the sheet or film along with the cooling roll or the endless metal belt, and (c) thereafter inserting, pressing and cooling the sheet or film between the outer surface of the cooling roll and the outer surface of the endless metal belt.
2. The method as claimed in claim 1, in which the thermoplastic resin sheet or film is pressed under a pressure of 1 kg/cm2 or more between the outer surface of the cooling roll and the outer surface of the endless metal belt.
3. A method for producing a thermoplastic resin sheet or film, which comprises:
(a) melting under heat a raw thermoplastic resin material other than crystalline polypropylenic copolymer, to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline polypropylenic copolymer to form a resin sheet or film, (b) inserting the resulting resin sheet or film between a mirror-finished outer surface of a cooling roll and a mirror-finished surface of an endless metal belt, (c) moving and cooling the resin sheet or film while being kept in contact with the outer surface of the cooling roll between the cooling roll and the endless metal belt, (d) pressing the resin sheet or film from inside of the endless metal belt, (e) releasing the resin sheet or film from contact with the cooling roll, (f) further moving the resin sheet or film while being kept adhered to the endless metal belt, and (g) then peeling the resin sheet or film from the endless metal belt.
(a) melting under heat a raw thermoplastic resin material other than crystalline polypropylenic copolymer, to which have been added one or more additives selected from the group consisting of a nucleating agent, fine powder of a high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline polypropylenic copolymer to form a resin sheet or film, (b) inserting the resulting resin sheet or film between a mirror-finished outer surface of a cooling roll and a mirror-finished surface of an endless metal belt, (c) moving and cooling the resin sheet or film while being kept in contact with the outer surface of the cooling roll between the cooling roll and the endless metal belt, (d) pressing the resin sheet or film from inside of the endless metal belt, (e) releasing the resin sheet or film from contact with the cooling roll, (f) further moving the resin sheet or film while being kept adhered to the endless metal belt, and (g) then peeling the resin sheet or film from the endless metal belt.
4. A method for producing a non-stretched transparent sheet or film of a thermoplastic resin, the sheet or film having glossy surfaces and being adapted for a wrapping material for food or medicine, which process employs a device including a cooling roll and an endless metal belt and which process comprises:
(a) melting and forming a raw crystalline thermoplastic resin material which is selected from the group consisting of polyethylene, polypropylene and polyethylene terephthalate and to which has been added at least one additive selected from the group consisting of:
(i) 0.5 to 10,000 ppm by weight of a nucleating agent selected from the group consisting of talc, organic carboxylic acids or their metal salts, metal salts of organic phosphinic acids, polyvinylcycloalkanes and dibenzylidene-sorbitol derivatives, (ii) 0.5 to 10,000 ppm by weight of fine powder of a high melting point polymer having a melting point of 200°C or higher and a particle size of 1 µm or less, (iii) 3 to 30% by weight based on the thermoplastic resin of a terpene resin or a petroleum resin having a molecular weight of from 500 to 5,000 and softening point of from 50 to 170°C, and (iv) an organic peroxide having a half-life period of 0.5 minute or longer at 150°C in an amount effective to decompose the raw thermoplastic resin, into a resin sheet or film;
(b) bringing the resulting still hot sheet or film into contact with and adhering it to a mirror-finished outer surface of the cooling roll or a mirror-finished outer surface of the endless metal belt and then moving the sheet or film along with the cooling roll or the endless metal belt, and (c) thereafter inserting, pressing and cooling the sheet or film between the outer surface of the cooling roll and the outer surface of the endless metal belt.
(a) melting and forming a raw crystalline thermoplastic resin material which is selected from the group consisting of polyethylene, polypropylene and polyethylene terephthalate and to which has been added at least one additive selected from the group consisting of:
(i) 0.5 to 10,000 ppm by weight of a nucleating agent selected from the group consisting of talc, organic carboxylic acids or their metal salts, metal salts of organic phosphinic acids, polyvinylcycloalkanes and dibenzylidene-sorbitol derivatives, (ii) 0.5 to 10,000 ppm by weight of fine powder of a high melting point polymer having a melting point of 200°C or higher and a particle size of 1 µm or less, (iii) 3 to 30% by weight based on the thermoplastic resin of a terpene resin or a petroleum resin having a molecular weight of from 500 to 5,000 and softening point of from 50 to 170°C, and (iv) an organic peroxide having a half-life period of 0.5 minute or longer at 150°C in an amount effective to decompose the raw thermoplastic resin, into a resin sheet or film;
(b) bringing the resulting still hot sheet or film into contact with and adhering it to a mirror-finished outer surface of the cooling roll or a mirror-finished outer surface of the endless metal belt and then moving the sheet or film along with the cooling roll or the endless metal belt, and (c) thereafter inserting, pressing and cooling the sheet or film between the outer surface of the cooling roll and the outer surface of the endless metal belt.
5. The method according to claim 4, wherein the raw crystalline thermoplastic resin is polypropylene.
6. The method according to claim 5, wherein the endless metal belt and the cooling roll are kept at a temperature of from 10 to 90°C; and the resin sheet is pressed between the outer surface of the cooling roll and the outer surface of the endless metal belt at a pressure of 1 to 20 kg/cm2.
7. The method according to claim 6, wherein the raw crystalline thermoplastic resin is propylene homopolymer.
8. The method according to claim 6, wherein to the raw crystalline thermoplastic resin, the nucleating agent (i) has been added.
9. The method according to claim 8, wherein the nucleating agent is a dibenzylidene-sorbitol derivative of the general formula, (I) (wherein R represents C1-8alkyl, halogen or C1-4alkoxy, and m represents an integer of from 0 to 3), and is contained in an amount of from 100 to 10,000 ppm by weight relative to the raw crystalline thermoplastic resin.
10. The method according to any one of claims 4 through 9, wherein a pressure roll having a non-sticking surface is used to press the sheet or film against the mirror-finished surface of the cooling roll or of the endless metal belt in step (b).
11. A method for producing a non-stretched transparent sheet or film of a thermoplastic resin, the sheet or film having glossy surfaces and being adapted for a wrapping material for food or medicine, which process employs a device including a cooling roll and an endless metal belt and which process comprises:
(a) melting and forming a raw crystalline thermoplastic resin material which is selected from the group consisting of polyethylene, propylene homopolymer and polyethylene terephthalate and to which has been added at least one additive selected from the group consisting of:
(i) 0.5 to 10,000 ppm by weight of a nucleating agent selected from the group consisting of talc, organic carboxylic acids or their metal salts, metal salts of organic phosphinic acids, polyvinylcycloalkanes and dibenzylidene-sorbitol derivatives, (ii) 0.5 to 10,000 ppm by weight of fine powder of a high melting point polymer having a melting point of 200°C or higher and a particle size of 1 µm or less, (iii) 3 to 30% by weight based on the thermoplastic resin of a terpene resin or a petroleum resin having a molecular weight of from 500 to 5,000 and softening point of from 50 to 170°C, (iv) an organic peroxide having a half-life period of 0.5 minute or longer at 150°C in an amount effective to decompose the raw thermoplastic resin, and (v) a crystalline polypropylenic copolymer in an amount of 0.2 to 40 parts by weight relative to 100 parts by weight of the raw thermoplastic resin, into a resin sheet or film;
(b) inserting the resulting still hot resin sheet or film between a mirror-finished outer surface of the cooling roll and a mirror-finished outer surface of the endless metal belt;
(c) moving and cooling the resin sheet or film while being kept in contact with the outer surface of the cooling roll between the cooling roll and the endless metal belt;
(d) pressing the resin sheet or film from inside of the endless metal belt against the cooling roll;
(e) releasing the resin sheet or film from contact with the cooling roll;
(f) further moving the resin sheet or film along with the endless metal belt while being kept adhered to the endless metal belt; and (g) peeling the resin or sheet off the endless metal belt.
(a) melting and forming a raw crystalline thermoplastic resin material which is selected from the group consisting of polyethylene, propylene homopolymer and polyethylene terephthalate and to which has been added at least one additive selected from the group consisting of:
(i) 0.5 to 10,000 ppm by weight of a nucleating agent selected from the group consisting of talc, organic carboxylic acids or their metal salts, metal salts of organic phosphinic acids, polyvinylcycloalkanes and dibenzylidene-sorbitol derivatives, (ii) 0.5 to 10,000 ppm by weight of fine powder of a high melting point polymer having a melting point of 200°C or higher and a particle size of 1 µm or less, (iii) 3 to 30% by weight based on the thermoplastic resin of a terpene resin or a petroleum resin having a molecular weight of from 500 to 5,000 and softening point of from 50 to 170°C, (iv) an organic peroxide having a half-life period of 0.5 minute or longer at 150°C in an amount effective to decompose the raw thermoplastic resin, and (v) a crystalline polypropylenic copolymer in an amount of 0.2 to 40 parts by weight relative to 100 parts by weight of the raw thermoplastic resin, into a resin sheet or film;
(b) inserting the resulting still hot resin sheet or film between a mirror-finished outer surface of the cooling roll and a mirror-finished outer surface of the endless metal belt;
(c) moving and cooling the resin sheet or film while being kept in contact with the outer surface of the cooling roll between the cooling roll and the endless metal belt;
(d) pressing the resin sheet or film from inside of the endless metal belt against the cooling roll;
(e) releasing the resin sheet or film from contact with the cooling roll;
(f) further moving the resin sheet or film along with the endless metal belt while being kept adhered to the endless metal belt; and (g) peeling the resin or sheet off the endless metal belt.
12. The method according to claim 11, wherein the raw crystalline thermoplastic resin material is propylene homopolymer.
13. The method according to claim 12, wherein the cooling roll and the endless metal belt are kept to a temperature of from 10 to 50°C.
14. The method according to claim 13, wherein the raw crystalline thermoplastic resin material contains the crystalline polypropylenic copolymer (v).
15. The method according to claim 13, wherein to the raw crystalline thermoplastic resin, the nucleating agent (i) has been added.
16. The method according to claim 15, wherein the nucleating agent is a dibenzylidene-sorbitol derivative of the general formula:
(I) (wherein R represents C1-8alkyl, halogen or C1-4alkoxy, and m represents an integer of from 0 to 3), and is contained in an amount of from 100 to 10,000 ppm by weight relative to the raw crystalline thermoplastic resin.
(I) (wherein R represents C1-8alkyl, halogen or C1-4alkoxy, and m represents an integer of from 0 to 3), and is contained in an amount of from 100 to 10,000 ppm by weight relative to the raw crystalline thermoplastic resin.
17. The method according to any one of claims 11 through 16, wherein an inner cooling pressure roll is employed for pressing the resin sheet or film from inside of the endless metal belt against the cooling roll in the step (d) at a pressure of 5 to 50 kg/cm2 in terms of a line pressure or 5 to 30 kg/cm2 in terms of a plane pressure, the inner cooling pressure roll being located inside a loop of the endless metal belt and downstream of the cooling roll against which the resin sheet or film is pressed so that the still hot resin sheet or film is brought into contact with the endless metal belt before the resin sheet or film is pressed by the inner cooling pressure roll.
18. The method according to any one of claims 11 through 16, wherein an inner hydraulic pressure device is employed for pressing the resin sheet or film from inside of the endless metal belt against the cooling roll in step (d).
19. The method according to any one of claims 11 through 16, wherein planet rolls are employed for pressing the resin sheet or film from inside of the endless metal belt against the cooling roll in step (d).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP67389/1993 | 1993-03-04 | ||
| JP06738993A JP3337261B2 (en) | 1993-03-04 | 1993-03-04 | Method for producing polypropylene resin sheet or film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2116389A1 CA2116389A1 (en) | 1994-09-05 |
| CA2116389C true CA2116389C (en) | 1997-04-29 |
Family
ID=13343585
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002116389A Expired - Fee Related CA2116389C (en) | 1993-03-04 | 1994-02-24 | Method for producing thermoplastic resin sheet or film |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US5658514A (en) |
| EP (1) | EP0614748B1 (en) |
| JP (1) | JP3337261B2 (en) |
| KR (1) | KR0131055B1 (en) |
| AU (1) | AU667607B2 (en) |
| CA (1) | CA2116389C (en) |
| DE (1) | DE69411609T2 (en) |
| ES (1) | ES2121102T3 (en) |
| TW (1) | TW302381B (en) |
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| JP4237275B2 (en) * | 1995-11-14 | 2009-03-11 | 出光興産株式会社 | Polypropylene resin sheet or film manufacturing method and manufacturing apparatus thereof |
| US6306327B1 (en) | 1995-11-14 | 2001-10-23 | Idemitsu Petrochemical Co., Ltd. | Producing method of a thermoplastic resin sheet and producing apparatus therefor |
| DE19605951C2 (en) * | 1996-02-17 | 1998-07-02 | Adolf Dipl Ing Seide | Smoothing unit for the production of sheets and foils made of thermoplastic plastic smoothed on both sides |
| USRE38495E1 (en) * | 1996-03-06 | 2004-04-13 | Idemitsu Petrochemical Co., Ltd. | Method for manufacturing thermoplastic sheets bearing embossed patterns thereon and an apparatus therefor |
| CA2198971A1 (en) * | 1996-03-06 | 1997-09-06 | Idemitsu Petrochemical Company Limited | A method for manufacturing thermo-plastic sheets bearing embossed patterns thereon and an apparatus therefor |
| US6372324B1 (en) * | 1997-02-28 | 2002-04-16 | Idemitsu Petrochemical Co., Ltd. | Soft transparent polyethylene resin sheet and process for producing the same |
| US5837177A (en) * | 1997-06-23 | 1998-11-17 | Aristech Chemical Corporation | Controlled nucleation of polypropylene in biaxially oriented films |
| US6129877A (en) * | 1998-09-04 | 2000-10-10 | Kuc, Sr.; John | Method and system for fabricating elastomeric articles |
| DE60042819D1 (en) * | 1999-02-16 | 2009-10-08 | Sumitomo Bakelite Co | METHOD OF MANUFACTURING THERMOPLASTIC PLASTIC FLAT FILM |
| JP4486202B2 (en) * | 2000-02-01 | 2010-06-23 | 出光興産株式会社 | Low crystalline polypropylene sheet and method for producing low crystalline polypropylene sheet |
| AU2001295332A1 (en) * | 2000-10-12 | 2002-04-22 | Decoma Exterior Trim Inc. | Adhesive backing on end formed trim pieces |
| DE60133133T2 (en) * | 2001-04-06 | 2009-06-25 | Idemitsu Kosan Co. Ltd. | POLYPROPYLENE FOIL WITH LOW CRYSTALLINITY |
| JP4441803B2 (en) * | 2002-12-12 | 2010-03-31 | 株式会社シーティーイー | Method and apparatus for producing thermoplastic synthetic resin sheet or film |
| US20050275132A1 (en) * | 2004-06-15 | 2005-12-15 | Eastman Kodak Company | Belt over compliant roller used with molding roller |
| US7465163B2 (en) * | 2004-06-15 | 2008-12-16 | Rohm And Haas Denmark Finance A/S | Smooth compliant belt for use with molding roller |
| JP4870522B2 (en) * | 2005-11-22 | 2012-02-08 | 富士フイルム株式会社 | Method for producing thermoplastic resin film |
| TWI387526B (en) * | 2006-06-06 | 2013-03-01 | Fujifilm Corp | Thermoplastic film and method of producing the same, polarizing plate, optical compensation film, antireflection film and crystal display device |
| US20100030180A1 (en) * | 2006-10-18 | 2010-02-04 | Tekni-Plex Europe, Naamloze Vennootschap | Method for manufacturing a multi-layered film and film manufactured by said method |
| US8221109B2 (en) | 2006-12-05 | 2012-07-17 | Gold Tip, Llc | Material layering device |
| JP5390078B2 (en) * | 2007-07-06 | 2014-01-15 | 出光ユニテック株式会社 | Polypropylene molded product, sheet-like polypropylene molded product, and method for producing polypropylene thermoformed product |
| JP5388263B2 (en) | 2007-09-04 | 2014-01-15 | 株式会社Ａｄｅｋａ | Master batch for polyolefin resin nucleating agent |
| JP5173476B2 (en) * | 2007-12-05 | 2013-04-03 | 富士フイルム株式会社 | Thermoplastic resin film production equipment |
| DE102009020624A1 (en) * | 2009-05-09 | 2010-11-11 | Nordenia Deutschland Gronau Gmbh | Process for producing a surface protection film |
| JP5742113B2 (en) * | 2010-05-12 | 2015-07-01 | 住友化学株式会社 | Polypropylene unstretched film |
| JP5763337B2 (en) * | 2010-12-28 | 2015-08-12 | 出光ユニテック株式会社 | Transparent multilayer sheet and molded article thereof |
| JP2012215856A (en) * | 2011-03-31 | 2012-11-08 | Sumitomo Chemical Co Ltd | Polarizing plate |
| WO2016017748A1 (en) * | 2014-07-31 | 2016-02-04 | 三菱瓦斯化学株式会社 | Optical film, multilayer optical film including same, and method for producing optical film |
| WO2017094083A1 (en) * | 2015-11-30 | 2017-06-08 | 日立化成株式会社 | Food packaging film |
| JP7337834B2 (en) | 2018-10-29 | 2023-09-04 | 株式会社瑞光 | Method and apparatus for producing thermoplastic film |
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| US4049589A (en) * | 1973-03-19 | 1977-09-20 | Sumitomo Electric Industries, Ltd. | Porous films of polytetrafluoroethylene and process for producing said films |
| JPS6032572B2 (en) * | 1979-10-26 | 1985-07-29 | 新神戸電機株式会社 | Manufacturing method of thermoplastic resin sheet |
| US4548778A (en) * | 1983-09-26 | 1985-10-22 | Idemitsu Petrochemical Co., Ltd. | Method of producing thermoplastic resin sheet or film |
| JPS60236719A (en) * | 1984-05-11 | 1985-11-25 | Idemitsu Petrochem Co Ltd | Cooler for thermoplastic resin |
| JPS6124977A (en) * | 1984-07-13 | 1986-02-03 | 井関農機株式会社 | Detector for flow-down of cereal grain in cereal grain drier |
| JPH0231507B2 (en) * | 1984-07-25 | 1990-07-13 | Kogyo Gijutsuin | HANDOTAISOCHI |
| JPS6210816A (en) * | 1985-07-08 | 1987-01-19 | 三菱電機株式会社 | Transparent electrode plate |
| JPS6241457A (en) * | 1985-08-15 | 1987-02-23 | Nissan Motor Co Ltd | Speed change control device for automatic speed change gear |
| JPS62284719A (en) * | 1986-06-03 | 1987-12-10 | Toppan Printing Co Ltd | Method for forming plastic film or sheet |
| JPS6242822A (en) * | 1986-08-01 | 1987-02-24 | Idemitsu Petrochem Co Ltd | Manufacture of thermoplastic resin sheet or film |
| JPS6360726A (en) * | 1986-09-01 | 1988-03-16 | Toppan Printing Co Ltd | Manufacture of highly transparent plastic film or sheet |
| JP2510654B2 (en) * | 1988-02-10 | 1996-06-26 | 株式会社細川洋行 | Method for producing non-oriented polypropylene film |
| JPH0689191B2 (en) * | 1988-05-26 | 1994-11-09 | 出光石油化学株式会社 | Method for producing sheets made of polypropylene resin composition |
| IT1226292B (en) * | 1988-07-22 | 1990-12-27 | Steel Belt System S R L | CONVEYOR BELT CONVEYOR WITH HEAT EXCHANGE, PARTICULARLY FOR LAMINAR AND SIMILAR PRODUCTS |
| JPH0637572B2 (en) * | 1990-02-20 | 1994-05-18 | チッソ株式会社 | Stretched molding having pearly luster and method for producing the same |
| JPH0649324B2 (en) * | 1990-05-11 | 1994-06-29 | ソマール株式会社 | Resin sheet having fine uneven surface and method for producing the same |
| JPH0764008B2 (en) * | 1990-10-23 | 1995-07-12 | 出光石油化学株式会社 | Method for producing polypropylene resin sheet or film |
| US5204037A (en) * | 1991-01-25 | 1993-04-20 | Idemitsu Petrochemical Co., Ltd. | Process for production of polypropylene sheets or films |
-
1993
- 1993-03-04 JP JP06738993A patent/JP3337261B2/en not_active Expired - Lifetime
-
1994
- 1994-02-22 TW TW083101506A patent/TW302381B/zh active
- 1994-02-23 ES ES94102679T patent/ES2121102T3/en not_active Expired - Lifetime
- 1994-02-23 AU AU55296/94A patent/AU667607B2/en not_active Ceased
- 1994-02-23 EP EP94102679A patent/EP0614748B1/en not_active Expired - Lifetime
- 1994-02-23 DE DE69411609T patent/DE69411609T2/en not_active Expired - Fee Related
- 1994-02-24 CA CA002116389A patent/CA2116389C/en not_active Expired - Fee Related
- 1994-02-28 KR KR1019940003750A patent/KR0131055B1/en not_active IP Right Cessation
-
1995
- 1995-02-01 US US08/384,478 patent/US5658514A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE69411609D1 (en) | 1998-08-20 |
| AU5529694A (en) | 1994-09-15 |
| EP0614748B1 (en) | 1998-07-15 |
| DE69411609T2 (en) | 1998-11-26 |
| US5658514A (en) | 1997-08-19 |
| JP3337261B2 (en) | 2002-10-21 |
| KR940021627A (en) | 1994-10-19 |
| TW302381B (en) | 1997-04-11 |
| KR0131055B1 (en) | 1998-04-13 |
| EP0614748A1 (en) | 1994-09-14 |
| JPH06254946A (en) | 1994-09-13 |
| CA2116389A1 (en) | 1994-09-05 |
| AU667607B2 (en) | 1996-03-28 |
| ES2121102T3 (en) | 1998-11-16 |
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Legal Events
| Date | Code | Title | Description |
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| EEER | Examination request | ||
| MKLA | Lapsed |