DE2927633A1 - METHOD FOR THE PRODUCTION OF HOT-WELDABLE AND NON-FIBROUS POLYOLEFIN FILMS - Google Patents

Description

DR. STEPHAN G. BESZfDES PATENT ADVOCATE

APPROVED REPRESENTATIVE "- ALSO AT THE EUROPEAN PATENT OFFICE

PROFESSIONAL REPRESENTATIVE ALSO BEFORE THE EUROPEAN PATENT OFFICE DACHAU NEAR MUNICH

^PO8TFA 2 $ 27633

MDNCHENER STRASSE 8OA

Federal Republic of Germany

B "e" scream TELEPHONE: DACHAU 4371

- Post check account Munich (BLZ 700 100 80}

Comq no. 1 SGb 7f

_Bank account no. 805370 at the KrUs- ond Sitdtspartasse Dachau-Indersdorf (BLZ 7Ü0 51540)

(VlA Bayerische Lanrfesbank

Girozentrale, Munich)

P 1 226

for patent application

MOPLEFAK S.p.A

Kilano, Italy

concerning

Process for the production of heat-sealable and non-fiber-forming polyolefin filaments

The invention relates to a new method for the production of heat-weldable. and non-fiber-forming polyolefin films from a single type of olefin polymers or copolymers or mixtures thereof '

909885/07 (10

by a combination of a plurality of consecutive Stran ^ press type, side aisles and suitable stretching work

It is well known that those intended for packaging are nuts Kateria] ien a combo nation of properties both mechanical as well as aesthetic and in particular gas and air impermeability, arm weldability, transparency, gloss and many other properties, which are difficult to achieve simultaneously with films obtained from a single type of bollard. Hence the use of composite foils, Laminate and lacquered films, which through Combination of polymers of different types obtained are taken to help.

There are also laminate films and composite films, what polyolefin films and films of other thermoplastic Polymers or metal foils, in particular aluminum foils, are known.

Sprinklers are made of unstretched polyolefin filaments and For then other thermoplastic materials to be stretched Composite films obtained from polymers as well as by extrusion molding of olefin polymers Films obtained from other thermoplastic polymers Films known.

The invention is based on the object of a better

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^ ORiGiNAL

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Process for the production of well heat-weldable and non-fiber-forming polyolefin films with superior mechanical and aesthetic properties, which also include superior resistance to sticking, respectively Adhere to the welding rods of the processing machines for them to create show.

It has now surprisingly been found that such heat-sealable and non-fiber-forming polyolefin films can be obtained in such a way that on a polyolefin base A polyolefin which is the same as that of the polyolefin base film is extruded and therewith suitable stretching operations can be combined. So it is the use of the same polymer for both the production of the base film as well as for its coating.

The invention therefore relates to a method for production of heat sealable and non-fiber forming polyolefin films by a combination of sequential ones "Stra.ngpreß- and stretching operations in the longitudinal and Transverse direction including the extrusion of olefin polymers or copolymers or respectively Mixtures thereof on films, which is characterized in that

a) a mono-oriented base film by extrusion of. crystalline polymers or copolymers of o (-01ef ines or mixtures thereof, by cooling the film to temperatures of 10 to 70 ⁰ C and then

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ORIGINAL

2327633

Stretching the same in the longitudinal direction at 110 to 150 ⁰ C with stretching ratios of 1: 4 to 1: 7 is produced,

b) the same polymer or copolymer or the same mixture thereof, which or which was used in the production of the base film on one or both surfaces of the base film to one

1

Coating layer with a thickness of -r- to _T L of the thickness of the base film is extruded and

c) the coated film at a temperature of 120 to 160 ° C using stretch ratios is stretched from 1: 6 to 1:10 in the transverse direction.

The films produced according to the invention are suitable for Manufacture of containers, sachets, covers, pouches or sachets, vessels and general objects for the packaging industry.

According to the invention, as polymers or Copolymers or their mixtures, both for the formation of the base film and for its outer layer zv / corner such crystalline polymers respectively Coprlymers of c <-olefins, which with stereospecific Catalysts prepared can be used.

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2327633

Preferably, both for the production of the Basic film as well as isotactic for its coating "or: predominantly isotactic macromolecules comprising polypropylene or crystalline copolymers of propylene and ethylene with a predominant Propylene unit content either of the block copolymer type or of the copolymer type with a random arrangement of their units or mixtures of polyethylene and crystalline polypropylene, polyethylene and crystalline copolymers of propylene and ethylene or of polypropylene and crystalline copolymers of propylene and ethylene, in particular with a melt index of __0.1 to JO, used.

If appropriate, these polymers and polyamide mixtures can be used Additions of matting agents, stabilizers, lubricants, fillers and / or organic xmd / or inorganic pigments contain. "-.-.

The polyolefin films obtained by the process of the present invention show good variable weldability properties and good mechanical and aesthetic properties, they are non-fibrous and show good resistance _ against sticking or sticking to the welding rods for the manufacture of containers, Sacks, envelopes, pouches or sachets, vessels and general objects for the packaging industry used automatic or semi-automatic Machines, ■ _ "-

The figure is a schematic representation of a for

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8AD ORIGINAL

Implementation of the method according to the invention can be used Contraption.

In this are an extruder 1 for extruding the base film, then a cooling unit 2, then a preheating unit 3 »dc near eh. A longitudinal stretching unit 4, then extrusion units 5, 5 ¹ for extrusion of the olefin polymer onto one or both surfaces of the base film and finally a transverse stretching unit 6.

The licensing of the cock of the crf irdunfjscerch'ß hurried over

Films to the weld were made by cr. Cc en of cr .-, ft each

Unit of area (in g / cin) used for detaching or separating a connected to an Instron dynamometer and welding under conditions similar to those normally used in packaging machines (part doors from 130 to 150 C, pressure 2.8 kg / cm and a time of 1 second) is necessary from the welding elements with the dyrifimometer.

The Fn so j-formation;: - tendency was assessed by observation with an optical microscope according to the Dc-hr-iDig i / it the mentioned.

The seal strength vmrde rated kg / cm welded Froben at 135-150 ⁰ C with said dynamometer atifeinajjdergelegten and with a welding device of the type under Sentinel knurled or ribbed bars for 1 second under a pressure of 2.80.

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- '. · ■ -. ■' .-. ■■: ■ * ■■ '■■■

The invention is illustrated by the following examples explained in more detail.

example 1

A heat-weldable and non-fiber-forming polypropylene film was produced by film extrusion of a crystalline polypropylene predominantly with isotactic macromolecules, with a melt index of 1, with a residue of 97j2 Cew. ™% in the heptane extraction and with an ash content of 0.01 % by weight, which has been prepared by stereospecific polymerization of propylene, using the apparatus shown in the figure. . ■

The film production was carried out with the help of the following carried out in successive operations:

A) Production of the unstretched film Extrusion of the polypropylene.

B) Cooling on rollers to 40 ° C.

C) Stretching in the longitudinal direction at 140 ° C with "." . a stretching ratio of 1: 5

; D) extruding a polypropylene with the same Data such as that of the polypropylene of the base film on the nrono-oriented stretched

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BATH

Film using a ratio of the Basic filifies to the coating film of 8: 1.

E) Stretching in the transverse direction at 155 ° C with a draw ratio of 1: 8.

F) Winding up.

The coated film thus obtained had the following Characteristics:

Coating 3 thickness & thickness

Breaking load

in the transverse direction 2,600 kg / cm ² in the longitudinal direction 1 JOO kg / cm

strain

■ in the transverse direction

c in he longitudinal direction of 180%

Adhesion (self-adhesive tape attempt) $ 100

Unwanted sticking relational 3 °

Bake at '+ 3 ° C (ASTM D-H ^ G / ^) 200

Transparency (ASTM D-1OO3 / i? 9T) 2

Slidability (coefficient of

static friction TMI). 0.5

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I? AD 0R! Gii4AL

-r-

Weld strength

at
at

70 g / cm 250 g / em

Fa serbildungsneigung

Adhering or sticking to welding rods no

at 13O ⁰ C 0 at 140 ⁰ G 0 at 150 ^° C 0

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909885/0700

Example 2

It became heat-weldable and non-fiber-forming Polypropylene film by film extrusion of a crystalline polypropylene predominantly with isotactic Macromolecules, with a melt index of 2, with a residue of 97 »2% by weight in the heptane extraction and with an ash content of 0.01 wt .-%, which by stereospecific Polymerization of propylene has been produced using the apparatus shown in the figure manufactured.

Filin production was carried out with the help of the following sequential Operations carried out:

A) Production of the unstretched film by extrusion molding of the polypropylene.

B) cooling to VTalzen 40 ⁰ C.

C) Longitudinal stretching at 140 ° C with a stretch ratio of 1: 5-

D) Extrusion of a polypropylene with the same data as that of the polypropylene of the Base film to the mono-oriented "film using a ratio of the base film to the coating film of 8: 1.

E) Stretching in the transverse direction at 155 ° C with a stretch ratio of 1: 8.

F) Winding up. '#

The coated film thus obtained had the following properties:

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'QRiGH:' AL fN-0:> - C7cD

• / 13.

Thickness of the coating J μ

Breaking load

"in the transverse direction 2,800 kg / cm in the longitudinal direction 1,300 kg / cm ^

strain

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BATH ORIGINAL

• in the Queirrichtujjg in the longitudinal direction

Adhesion (self-adhesive tape test) - 100% Unwanted sticking, respectively

Bake at $ 4 ° C (ASTM D-11 ^ 6/53) 200

By security (ASTM Ώ - 1ΟΟ3 / ^ 9ΐ) 2

Guidance (coefficient of

static friction 'J ¹ MI) x 0.5

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• 4k

2327633

Weld strength _t

at

at 150 ° C

70 g / cm 25Ο g / cm

Tendency to develop no

Adhesion respectively
Sticking to welding rods

at 130 ⁰ C 0 at 14-0 ⁰ C 0 at 150 ⁰ C 0

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-AS-

Example 3

A heat-weldable and non-fiber-forming polypropylene film was produced by film extrusion of a crystalline polypropylene predominantly with isotactic macromolecules, with a melt index of 10, with a residue of 95% by weight in the heptane extraction and with an ash content of 0.01% by weight, which has been made by the stereospecific polymerization of propylene "" - is made using the apparatus shown in the figure. - - -

The film was made with the help of the following successive Operations carried out:

A) Production of the unstretched film by extrusion of the PolypxOpylerre.

B) cooling on rollers to 40 ^° C.

C) Stretching in the longitudinal direction at 14-0 ⁰ C with a stretching ratio of 1: 5 *

D) extruding a polypropylene with the same Data such as that of the polypropylene of the base film on the mono-oriented stretched Film using a ratio of base film to coating film of 8: 1.

E) Stretching in the transverse direction at 155 ° C with a draw ratio of 1: 8.

F) Winding up.

The coated film thus obtained had the following Characteristics:

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■ M> -

Thickness of the coating

Breaking load

in the transverse direction in the longitudinal direction 600 kg / cnT 200 kg / cm ²

strain

in the transverse direction in the longitudinal direction 50% 190%

Adhesion (self-adhesive tape test) 100%

Unwanted sticking or baking at 4 ° C (ASTM D-1146/53) 200

Transparency (ASTN D-1OO3 / 59T)

Slidability (coefficient of static friction TMI) 0.5

Welding resistance

Tendency to fiber formation

at 14o ° C at 145 ° C at 150 ° C 50 g / cm 100 g / cm

25O g / cm none

909885/0700 - 15 -

BATH ORIGINAL

Adhere or
Sticking to welding rods

at 13O ⁰ C 0 at 140 ° c O at 15O ⁰ G 0

Example 4 -

It became a waria-weldable and non-fiber-forming one Folypropylene film by film extrusion of a crystalline Polypropylenes predominate «· with isotactic macromolecules, with a melting index of 20, with a residue of 90% by weight in the case of the heptis extraction and with an ash content of 0.01 wt .-%, which by!., kereO-specific polymerization of propylene using the apparatus shown in the figure.

The film was made using the following on- ■ -. successive operations carried ^out:. _ ".

A) Manufacture of the unstretched polypi ^ opylenfilmes by extrusion of the polypropylene.

B) Kü) 1 en on rollers on AO ⁰ C.

G) stretching in the longitudinal direction at 140 ^° C. with a stretching ratio of 1: 5.

D) Extrusion of a polypropylene with the same data as that of the polypropylene of the Base film on the mono-oriented stretched

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BADORtGINAL

Film using a ratio of base film to coating film of 8: 1,

E) Stretching in the transverse direction at 155 ° C with a stretch ratio of 1: 8.

F) Winding up.

The coated film thus obtained had the following properties:

Thickness of the coating

3/1

Breaking load

in the transverse direction in the longitudinal direction

2,600 kg / cnT 1,200 kg / cm ²

strain

in the transverse direction in the longitudinal direction

50% 190%

Adhesion (self-adhesive tape test)

100%

Unwanted sticking or baking at 43 ° C (ASTM D-1146/53)

200

Transparency (ASTM D-1OO3 / 59T)

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Slidability (coefficient of

static friction TMI) 0.5

Weld strength

at 140 ° C 50 g / cm at .14-5 ⁰ C 250 g / cm

at 150 ^° C. 300 g / cm

No tendency to fiber formation

Stick respectively
Gluing to welding rods

at 130 ° C 0 at 140 ⁰ C 0 at 150 ⁰ G 0

Example

It became a heat sealable. and non-fiber-forming polyolefin film by film extrusion of a randomly arranged crystalline copolymer of propylene and ethylene containing 2.7% by weight of ethylene units, having a melt index of 8 and having an ash content of 0.0078% by weight, which has been prepared by copolymerization of propylene with ethylene by means of stereospecific catalysts, using the apparatus shown in the figure.

909885/0700

The pilm production was carried out with the help of the following successive Operations carried out:

A) Production of the unstretched film by extrusion molding of the copolymer.

B) cooling on rollers to 40 ^° C.

C) Stretching in the longitudinal direction at 125 ° C with a stretching ratio of 1: 5

D) Extrusion of a copolymer with the same data as that of the polypropylene of the base film on the mono-oriented stretched film using a ratio of the base film to the coating film of 8: 1.

E) Stretching in the transverse direction at 14-5 ° C with a draw ratio of 1: 8.

F) Winding up.

The coated FiDm thus obtained had the following Characteristics:

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BATH ORIGINAL

3ή

Thickness of the coating breaking load

in the transverse direction in the longitudinal direction

strain

in the transverse direction in the longitudinal direction

Adhesion (self-adhesive tape test)

Unwanted sticking or baking at 43 ⁰ C (ASTM D-1146/53) "

Transparency (ASTM D-1OO3 / 59T-)

Slidability ("coefficient of -." ■ static friction "T ¹ MX)

Welding strength

300 kg / cm ^{2,000 kg} / cm ²

50% 210%

100%

0.5

at 135 ^w c 200 g / cm at 140 ° C 300 g / cm at 145 ° C 300 g / cm at 150 ^° C 300 g / cm

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ORIGINAL.INSPECTED

. as.

χ *
No tendency to fiber formation

Be liable respectively at I ₅ O ⁰ C 0 Adhere on welding rods at 140 ⁰ C 0

Parental entitlements

809885/0700

Claims (2)

Claims Process for the production of wariA-weldable and non-fiber-forming polyolefin films by a combination of sequential ones Extrusion and stretching operations in the longitudinal and transverse directions, including extrusion of olefin polymers or copolymers or mixtures thereof on films, characterized in that: a) a mono-oriented basic film Extrusion of crystalline polymers .'_ or copolymers of '' olefins or mixtures thereof, by cooling the film to temperatures of 10 to 0 ° C and then stretching the same in the longitudinal direction at 110 to 15O ⁰ C and Streckverhaitnxssen by:? "_ 1: 4 to 1: 7 manufactures, b) the same polymer or copolymer beziehungsv / else di eselbe mixture thereof, which bt ^ .iehungsv; else which was used in the preparation of the ⁿ base film, on one or both surfaces of a coating layer to Gruridfilmes 1 1 with a thickness of 4 to ~ the thickness of the base film strangpreßt wad c) Deii coated film at a temperature - "22- 909885/0700 8AI> ORIGINAL 2327633 from 120 to 160 ⁰ C, using stretching ratios from 1: 6 "to 1: 10 stretched in the transverse direction. 2.) The method according to claim 1, characterized in that one is used both for the production of the Basic film as well as for its "coating isotactic or predominantly isotactic ■ Polypropylene containing macromolecules or crystalline copolymers of propylene and ethylene with a predominant content of propylene units either of the block copolymer type or of the copolymer type with random arrangement their units or mixtures of polyethylene and crystalline polypropylene, of Polyethylene and crystalline copolymers of propylene and ethylene or of polypropylene and crystalline copolymers of propylene and ethylene, especially with a melt index of 0.1 to 30 is used. 509585/0700