CA2226549C - Coating composition - Google Patents
Coating composition Download PDFInfo
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- CA2226549C CA2226549C CA002226549A CA2226549A CA2226549C CA 2226549 C CA2226549 C CA 2226549C CA 002226549 A CA002226549 A CA 002226549A CA 2226549 A CA2226549 A CA 2226549A CA 2226549 C CA2226549 C CA 2226549C
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- blend
- ethylene polymer
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- molecular weight
- ethylene
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
- H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
- H01B3/44—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- C08F210/16—Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/04—Homopolymers or copolymers of ethene
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/04—Homopolymers or copolymers of ethene
- C08L23/08—Copolymers of ethene
- C08L23/0807—Copolymers of ethene with unsaturated hydrocarbons only containing more than three carbon atoms
- C08L23/0815—Copolymers of ethene with aliphatic 1-olefins
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
- G02B6/4401—Optical cables
- G02B6/4429—Means specially adapted for strengthening or protecting the cables
- G02B6/443—Protective covering
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
- Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
- Y10T428/1355—Elemental metal containing [e.g., substrate, foil, film, coating, etc.]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
- Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
- Y10T428/1355—Elemental metal containing [e.g., substrate, foil, film, coating, etc.]
- Y10T428/1359—Three or more layers [continuous layer]
Abstract
Conventional coating compositions have the disadvantage of being insufficiently coatable and having an unsatisfactory environmental stress cracking resistance. Now a coating composition has been found which h as both good coating processability and environmental stress cracking resistance. It comprises a multimodal ethylene polymer, which contains from 80 to 100 % by weight of ethylene repeating units and from 0 to 20 % by weight of C3-C10 .alpha.-olefin repeating units, has a density of between 0.915 g/cm3 and 0.955 g/cm3, and is a blend of at least a first ethylene polymer having a first average molecular weight and a first molecular weight distribution and a second ethylene polymer having a second average molecular weight, which is higher than said first average molecular weight, and a second molecular weight distribution, said blend having a third average molecular weight and a third molecular weight distribution.
Description
Coating composition The invention relates to a coating composition and its use for coating a solid substrate. Coatings are applied to su.rfaces of all types to provide protection and decoration. Protection may be required against corrosion, oxidative ageing, weathering, or against mechanical damage.
When coating without solvent, the coating material should have good processing properties, i.e. the material should be easily melt coatable within a wide temperature interval, low shrinking, high mechanical strength, high surface fmish and high environmental stress cracking resistance (ESCR). Since all these requirements have been difficult to fullfill, prior known coating materials have meant compromises whereby good properties in one sense have been achieved at the expense of good properties in another sense.
It would mean considerable advantages if the above mentioned compromise regarding the properties of a coating composition could be avoided. It would be particularly desirable to improve the coatability such as the melt flow properties when coating and the shrinkability of the coating material as well as the environmental stress cracking resistance of a product made from the coating material.
The purpose of the invention is to provide a coating material having good melt coating processability, low shrinking, high service temperature range and good environmental stress cracking resistance. The invention also strives for efficient coating speed expressed as high winding speed of the extruded material.
These purposes of the invention have now been achieved by means of a coating composition, which is substantially characterized in that it comprises a multimodal ethylene polymer, which contains from 80 to 100% by weight of ethylene repeating units and from 0 to 20% by weight of C3-C 10 a-olefm repeating units, has a density of between 0.915 g/cm3 and 0.955 g/cm3, and is a blend of at least a first ethylene polymer having a first average molecular weight and a first molecular weight distribution and a second ethylene polymer having a second molecular weight, which is higher than said first molecular weight, and a second molecular weight distribution, said blend having a third molecular weight and a third molecular weight distribution.
WO 97/03139 PCT/Fi96/00405 By a multimodal ethylene polymer is in connection with the present invention meant an ethylene polymer having broad molecular weight distribution produced by blending two or more ethylene polymer components with different molecular weights or by polymerizing ethylene to different molecular weights in a process with two or more reactors in series. By contrast, a unimodal ethylene polymer is obtained from only one ethylene polymer component produced in only one step.
The average molecular weights and the molecular weight distributions can be measured and expressed by any conventional method applied to ethylene polymer products. In this connection, it is convenient that the average molecular weights are measured and expressed as melt flow rates MFRIm, where i refers to said first, second and third average molecular weights and m refers to the load of the piston used for measuring the MFRs, which load in the following examples generally is 5.0 kg (m=5, see ISO 1133). The molecular weight distributions are conveniently expressed as flow rate ratios, FRRiml/m2, i.e. the ratios between high load MFRIs and low load MFRIs, where i refers to said first, second and third molecular weight distributions, and m I and m2 refer to the high load, generally 21.6 kg (m=21), and low load, generally 5.0 kg (m=5) or 2.16 kg (m=2), respectively.
By Melt Flow Rate (MFR) is meant the weight of a polymer pressed through a standard cylindrical die at a standard temperature in a laboratory rheometer canying a standard piston and load. Thus MFR is a measure of the melt viscosity of a polymer and hence also of its average molecular weight. The smaller the MFR, the larger is the average molecular weight. It is frequently used for characterizing a polyolefm, especially polyethylene, when the standard conditions MFRm are:
temperature 190 C; die dimensions 9.00 cm in length and 2.095 cm in diameter;
load of the piston, 2.16 kg (m=2), 5.0 kg (m=5), 10.0 kg (m=10), 21.6 kg (m=21).
See Alger, M.S.M., Polymer Science Dictionary, Elsevier 1990, p. 257.
By Flow Rate Ratio (FRRml/m2) is meant the ratio between the melt flow rate (MFRm 1) measured at a standard temperature and with standard die dimensions using a heavy load (m 1) and the melt flow rate (MFRm2) measured at the same =
temperature with the same die dimensions using a light load (m2). Usually, for ethylene polymers, the heavy load m I is 21.6 kg (m 1=21) and the light load m2 is 5.0 kg (m2=5) or 2.16 kg (m2=2) (ISO 1133). The larger the value of the FRRml/m2, the broader is the molecular weight distribution.
When coating without solvent, the coating material should have good processing properties, i.e. the material should be easily melt coatable within a wide temperature interval, low shrinking, high mechanical strength, high surface fmish and high environmental stress cracking resistance (ESCR). Since all these requirements have been difficult to fullfill, prior known coating materials have meant compromises whereby good properties in one sense have been achieved at the expense of good properties in another sense.
It would mean considerable advantages if the above mentioned compromise regarding the properties of a coating composition could be avoided. It would be particularly desirable to improve the coatability such as the melt flow properties when coating and the shrinkability of the coating material as well as the environmental stress cracking resistance of a product made from the coating material.
The purpose of the invention is to provide a coating material having good melt coating processability, low shrinking, high service temperature range and good environmental stress cracking resistance. The invention also strives for efficient coating speed expressed as high winding speed of the extruded material.
These purposes of the invention have now been achieved by means of a coating composition, which is substantially characterized in that it comprises a multimodal ethylene polymer, which contains from 80 to 100% by weight of ethylene repeating units and from 0 to 20% by weight of C3-C 10 a-olefm repeating units, has a density of between 0.915 g/cm3 and 0.955 g/cm3, and is a blend of at least a first ethylene polymer having a first average molecular weight and a first molecular weight distribution and a second ethylene polymer having a second molecular weight, which is higher than said first molecular weight, and a second molecular weight distribution, said blend having a third molecular weight and a third molecular weight distribution.
WO 97/03139 PCT/Fi96/00405 By a multimodal ethylene polymer is in connection with the present invention meant an ethylene polymer having broad molecular weight distribution produced by blending two or more ethylene polymer components with different molecular weights or by polymerizing ethylene to different molecular weights in a process with two or more reactors in series. By contrast, a unimodal ethylene polymer is obtained from only one ethylene polymer component produced in only one step.
The average molecular weights and the molecular weight distributions can be measured and expressed by any conventional method applied to ethylene polymer products. In this connection, it is convenient that the average molecular weights are measured and expressed as melt flow rates MFRIm, where i refers to said first, second and third average molecular weights and m refers to the load of the piston used for measuring the MFRs, which load in the following examples generally is 5.0 kg (m=5, see ISO 1133). The molecular weight distributions are conveniently expressed as flow rate ratios, FRRiml/m2, i.e. the ratios between high load MFRIs and low load MFRIs, where i refers to said first, second and third molecular weight distributions, and m I and m2 refer to the high load, generally 21.6 kg (m=21), and low load, generally 5.0 kg (m=5) or 2.16 kg (m=2), respectively.
By Melt Flow Rate (MFR) is meant the weight of a polymer pressed through a standard cylindrical die at a standard temperature in a laboratory rheometer canying a standard piston and load. Thus MFR is a measure of the melt viscosity of a polymer and hence also of its average molecular weight. The smaller the MFR, the larger is the average molecular weight. It is frequently used for characterizing a polyolefm, especially polyethylene, when the standard conditions MFRm are:
temperature 190 C; die dimensions 9.00 cm in length and 2.095 cm in diameter;
load of the piston, 2.16 kg (m=2), 5.0 kg (m=5), 10.0 kg (m=10), 21.6 kg (m=21).
See Alger, M.S.M., Polymer Science Dictionary, Elsevier 1990, p. 257.
By Flow Rate Ratio (FRRml/m2) is meant the ratio between the melt flow rate (MFRm 1) measured at a standard temperature and with standard die dimensions using a heavy load (m 1) and the melt flow rate (MFRm2) measured at the same =
temperature with the same die dimensions using a light load (m2). Usually, for ethylene polymers, the heavy load m I is 21.6 kg (m 1=21) and the light load m2 is 5.0 kg (m2=5) or 2.16 kg (m2=2) (ISO 1133). The larger the value of the FRRml/m2, the broader is the molecular weight distribution.
The present invention is based on the finding, that multimodal ethylene polymer has excellent coating application properties such as good processability and low shrinkage as well as superior environmental stress cracking resistance.
The coating composition according to the present invention is a multimodal ethylene polymer. The multimodal ethylene polymer is by definition a blend of at least two ethylene polymers having different molecular weights. According to an important embodiment of the present invention, said blend is the product. of a polymerization process comprising at least two steps. In the process, said first ethylene polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a first step and said second polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a second step. Said steps can be performed in any order, whereby the ethylene polymer of each step is present in the following step or steps.
However, it is preferential that said blend is the product of said polymerization process, wherein said first step is performed before said second step. This means, that first, an ethylene polymer having a lower average molecular weight is produced and then, in the presence of the lower molecular weight ethylene polymer, an ethylene polymer having a higher average molecular weight is produced.
The idea of the present invention can be realized with any kind of ethylene poly-merization catalyst, such as a chromium catalyst, a Ziegler-Natta catalyst or a group 4 transition metallocene catalyst. According to one embodiment of the present invention, said blend forming the multimodal ethylene polymer is the product of a polymerization process in which said first step and/or said second step is performed in the presence of a catalyst system comprising a procatalyst based on a tetravalent titanium compound, such as a TiClq,/MgC12/optional inert carrier/optional internal electron donor procatalyst, and a cocatalyst based on an organoaluminum compound, preferentially a R3AIUoptional external electron donor procatalyst wherein R is a C1-C10 alkyl. Typical catalyst systems are e.g. prepared according to W091/12182 and W095135323. A preferential single site polymerization catalyst system is that based on a group 4(IL'PAC 1990) metal metallocene and alurnoxane.
When performing said polvmerization process comprising at least two steps, one or more catalyst systems, which may be the same or different, can be used. It is preferential, if said blend is the product of said polymerization process, in which said catalyst system is added to said first step and the same catalyst system is used at least in said second step.
The most convenient way to regulate the molecular weight during the multistep polymerization of the present invention is to use hydrogen, which acts as a chain-transfer agent by intervening in the insertion step of the polymerization mechanism.
Hydrogen may be added in suitable amounts to any step of the multistep poly-merization. However, it is preferential that in said first step a hydrogen amount is used, leading to a melt flow rate MFR12 of said first ethylene polymer of from g/10 nmin. to 2000 g/min., most preferentially from 100 g/ 10 min. to 1000 g/
10 min., provided that said first step is performed before said second step.
It is prior known to prepare multimodal and especially bimodal olefin polymers in two or more polymerization reactors in series. Such processes are exemplified by EP
040992, EP 04179.fi, EP 022376 and W092/12182 which concern the preparation of the multimodal ethylene polymers for the claimed coating material. According to these references each of said polymerization steps can be performed in liquid phase, slurry or gas phase.
According to the present invention, it is preferential to perform said polymerization steps as a combination of slurry polymerization and gas phase polymerization.
Preferentially said first step is a slurry polymerization and said second step a gas phase polymerization.
The slurry polymerization is preferentially performed in a so called loop reactor.
The gas phase polymerization is performed in a gas phase reactor. The poly-merization steps can optionally be preceded by a prepolymerization, whereby up to 20% by weight and preferentially 1-10% by weight of the total ethylene polymer amount is formed.
Above, the use of hydrogen to regulate the molecular weight of the ethylene poly-mers is mentioned. The properties of the ethylcne polymers can also be modified by adding a small amount of a-olefin to any of said polyrnerizatio.n steps.
According to one embodiment of the present invention, said first ethylene polymer has a C3-a-olefin repeating unit content of from 0 to 10% by weight of said first ethylene polymer. Preferentially, in said second ethylene polymer, the C3-ClO a-olefin, such as 1-butene or 1-hexene, repeating unit content is from 1 to 25% by weight, most preferentially 2 to 15% by weight, of said second ethylene polymer.
When using only two steps in said polyznerization process, the ratio between the first produced ethylene polymer having the MFR12 defined above, and the second produced ethylene polymer, having a lower MFR, is between 20:80 and 80:20, preferentially between 20:80 and 60:40.
The above mentioned polymerization conditions of the different steps can be coordinated 5 so that the blend produced is most suitable for the coating of a solid substrate. Thus, the following preferential properties of said multimodal ethylene polymer blend can be achieved.
In one aspect, there is provided a use of a polymer composition for melt coating of a rigid pipe, pipe fitting or profile, characterized in that the composition has an environmental stress cracking resistance (ESCR, F20, ASTM 1693) of at least 100 h and comprises a multimodal ethylene polymer, which contains from 80 to 100% by weight of ethylene repeating units and from 0 to 20% by weight of C3-C10 a-olefin repeating units, has a density of between 0.915 g/cm3 and 0.955 g/cm3, and is a blend of at least a first ethylene polymer having a first average molecular weight corresponding to a melt flow rate MFR12 of from 50 g/10 min. to 2000 g/10 min. and a first molecular weight distribution and a second ethylene polymer having a second average molecular weight, which is higher than the first average molecular weight, and a second molecular weight distribution, the ratio between the first and second ethylene polymer being from 80:20 to 20:80, the blend having a third average molecular weight corresponding to a melt flow rate MFR32 of from 0.1 g/10 min. to 20 g/10 min. and a third molecular weight distribution. The pipe, pipe fitting or profile may be a rigid iron pipe, iron pipe fitting, iron profile, a rigid steel pipe, steel pipe fitting or steel profile.
In another aspect, there is provided a use of a composition characterized in that the blend is the product of a polymerization process comprising at least two steps in which the first ethylene polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a first step and the second ethylene polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a second step, the steps being performed in any order, the ethylene polymer of each step being present in the following step or steps.
In another aspect, there is provided a use of a composition characterized in that the blend 5a is the product of the polymerization process in which the first step and/or the second step is performed in the presence of a catalyst system comprising a procatalyst based on the tetravalent titanium compound procatalyst TiC14/1VIgC12/optional inert carrier/optional internal electron donor, and a cocatalyst based on a R3Al/optional external electron donor wherein R is a C1-Clo alkyl.
In another aspect, there is provided a use of a composition characterized in that the blend is the product of the polymerization process, in which the catalyst system is added to the first step and the same catalyst system is used at least in the second step.
In another aspect, there is provided a use of a composition characterized in that the blend is the product of the polymerization process, in the first step of which an amount of the chain transfer agent hydrogen, is used, which gives a melt flow rate MFR12 for the first ethylene polymer of from 100 g/10 min. to 1000 g/10 min., provided that step 1 is performed first.
In another aspect, there is provided use of a composition characterized in that the blend is the product of the polymerization process, in which the first step and the second step are performed as a slurry polymerization, gas phase polymerization or a combination thereof.
In another aspect, there is provided a use of a composition characterized in that in the blend is the product of the polymerization process, in which the first step is performed as a slurry polymerization, and the second step is performed as a gas phase polymerization.
In another aspect, there is provided a use of a composition characterized in that in the first ethylene polymer, the C3-Clo a-olefin repeating unit content is from 0 to 10%
by weight of the first ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that in the second ethylene polymer, the C3-Clo a-olefin repeating unit content is from 1 to 25% by weight and from 2 to 15% by weight, of the second ethylene polymer.
5b In another aspect, there is provided a use of a composition characterized in that in the second ethylene polymer, the C3-Clo a-olefin repeating unit content is from 2 to 15% by weight, of the second ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that in the blend, the ratio between the first ethylene polymer and the second ethylene polymer is between 20:80 and 60:40.
In another aspect, there is provided a use of a composition characterized in that the C3-Clo cc-olefin repeating unit content of the blend is from 0.2 to 20% by weight.
In another aspect, there is provided a use of a composition characterized in that the C3-Clo oc-olefin content is from 0.5 to 15% by weight, of the blend.
In another aspect, there is provided a use of a composition characterized in that the flow rate ratio FRR321i5 of the blend is between 10 and 50, the molecular weight distribution curve showing several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material.
In another aspect, there is provided a use of a characterized in that the blend is a mechanical mixture of at least the first ethylene polymer and the second ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that the blend is a mechanical melt mixture of the first ethylene polymer and the second ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that the ratio between the first ethylene polymer and the second ethylene polymer is between 20:80 and 60:40.
In another aspect, there is provided a use of a composition characterized in that the melt flow ratio MFRIZ of the first ethylene polymer is from 100 to 1000 g/10 min.
5c In another aspect, there is provided a use of a composition characterized in that the melt flow ratio MFR221 of the second ethylene polymer is from 0.05 to 50 g/10 min.
In another aspect, there is provided a use of a composition characterized in that the first ethylene polymer has a C3-Clo a-olefin repeating unit content of from 0 to 10%
by weight of the first ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that the second ethylene polymer has a C3-Clo a-olefin repeating unit content of from 1 to 25%
by weight of the second ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that the melt flow ratio MFR32 of the blend is between 0.1 and 50 g/10 min., preferentially between 0.1 and 20 g/10 min.
In another aspect, there is provided a use of a composition characterized in that the C3-Clo a-olefin repeating unit content of the blend is from 0.2 to 20% by weight.
In another aspect, there is provided a use of a composition characterized in that the flow rate ratio FRR321i5 of the blend is between 10 and 50, the molecular weight distribution curve showing several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material.
In another aspect, there is provided a use of a composition, characterized in that the blend is a blend which has been treated in a tailoring step comprising heating, melt processing and subjecting to controlled free radical reactions to give a molecular weight, which is at least as high as the molecular weight of the untreated blend, and a molecular weight distribution, which is broader than the molecular weight distribution of the untreated blend.
In another aspect, there is provided a use of a composition characterized in that the blend is a blend which has been treated in the tailoring step so that during the tailoring step, the 5d relative decrease in the ratio, -( MFR3' 5 - MFR35):MFR35, is from 10 to 80%, wherein MFRY 5 is the melt index of the blend after the tailoring step.
In another aspect, there is provided a use of a composition characterized in that the blend is a blend which has been treated in the tailoring step so that during the tailoring step, the relative broadening of the molecular weight distribution expressed as +( FRR3'21i5 +FRR321i5): FRR321i5 is from 10 to 80%, wherein FRR3' 21i5 is the flow rate ratio of the blend after the tailoring step.
In another aspect, there is provided a use of a composition characterized in that it has an environmental stress cracking resistance (ESCR, F20) of at least 500 h. In another aspect, there is provided a use of a composition characterized in that it has an environmental stress cracking resistance of at least 1000 h.
In another aspect, there is provided a use of a composition characterized in that the composition is used for coating of a substrate comprising an iron or a steel pipe, a primer, covering the iron or steel pipe, and a coupling agent, covering the primer, wherein the primer may be an epoxy lacquer and the coupling agent may be carboxy modified polyethylene.
According to a preferred embodiment of the present invention, the melt flow rate MFR32 of said blend is between 0.1 and 50 g/10 min., more preferably between 0.1 and 20 g/10 min. According to a preferred embodiment, the C3-lo a-olefin repeating unit content of said blend is from 0.2 to 20% by weight, more preferably from 0.5 to 15% by weight, of said blend. According to a preferred embodiment, the flow rate ratio FRR321i5 of said blend is between 10 and 50, more preferentially between 15 and 40. Thereby, it is advantageous if the molecular weight distribution corresponding to said flow rate ratio shows several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material.
As was described above, the multimodal ethylene polymer according to the invention can be produced in a polymerizing process having at least two steps leading to different 5e average molecular weights. According to another important embodiment of the invention, the multimodal ethylene polymer can be produced by mixing at least two ethylene polymers having different average molecular weights. In the latter case, said blend is a mechanical mixture of at least said first ethylene polymer and said second ethylene polymer, preferentially a mechanical mixture of said first ethylene polymer and said second ethylene polymer.
When mixing two ethylene polymers of different average molecular weight, the mixing is generally a melt mixing in a melt processing apparatus like a compounder and an extruder.
The product is then a mechanical melt mixture of at least said first ethylene polymer and said second ethylene polymer. Preferentially there are only two ethylene polymers so that the mechanical melt mixture is a mixture of said first ethylene polymer and said second ethylene polymer. The preferable ratio between said first ethylene polymer and said second ethylene polymer is between 20:80 and 80:20, most preferably between 20:80 and 60:40.
When feeding the first ethylene polymer to the mixing step, the melt flow ratio MFR12 of the first ethylene polymer is preferentially from 50 to 2000 g/10 min., .
most preferentially from 100 to 1000 g/ 10 min. When feeding at least said second ethylene polymer to the mixing step, its or their melt flow ratio MFR2, etc=Z1 is preferentially from 0.05 to 50 g/10 min., most preferentially from 0.10 to 20 g/IO
=
min.
In its most wide scope, the present invention relates to a coating composition comprising any multimodal ethylene polymer. This means, that the different ethylene polymers which can be used can have the monomer composition of a homopolymer or a copolymer. Preferentially said first ethylene polymer has a C I 0 a-olefin repeating unit content of 0.0 to 10% by weight, calculated from the weight of said ethylene polymer.
Usually at least one ethylene polymer component of said blend is an ethylene copolymer containing a small amount of another a-olefm. Preferentially, said second ethylene polymer has a C;-CIO a-olefm, preferentially 1-butene or 1-hexene, repeating unit content of from 1.0 to 25% by weight and most preferentially from 2.0 to 15% by weight. Typical other comonomers are 4-methyl-l-pentene and 1-octene. When a blend of more than two ethylene polymer components is used, the further ethylene polymer components can be either homopolymers or copolymers.
Conclusively, in the embodiment where the coating composition multimodal ethylene polymer is prepared by mixing at least a first ethylene polymer and a second ethylene polymer, the proportion of the first ethylene polymer and the second, etc., ethylene polymer, the MFR I, MFR2, etc. of said ethylene polymers and C3-C10 a-olefm repeating unit content of said ethylene polymers are preferentially such that the MFR32 of the blend obtained is between 0.1 and 50 g/10 min., preferentially between 0.1 and 20 g/l0 min. Correspondingly, but independently, the C3-CIO a-olefm repeating unit content of the said blend is from 0.2 to 20% by weight, preferentially from 0.5 to 15% by weight. The flow rate ratio FRR321/5 of said blend is between 10 and 50, preferentially between 15 and 40.
The molecular weight distribution curve shows either several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material. It was found, that, although the melt flow ratios, the comonomer repeating unit content and the flow rate ratio were essentially the same as in known mono-modal products, the mere fact that the ethylene polymer was multimodal, i.e.
was the blend of different molecular weight fractions, rendered it totally superior e.g.
The coating composition according to the present invention is a multimodal ethylene polymer. The multimodal ethylene polymer is by definition a blend of at least two ethylene polymers having different molecular weights. According to an important embodiment of the present invention, said blend is the product. of a polymerization process comprising at least two steps. In the process, said first ethylene polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a first step and said second polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a second step. Said steps can be performed in any order, whereby the ethylene polymer of each step is present in the following step or steps.
However, it is preferential that said blend is the product of said polymerization process, wherein said first step is performed before said second step. This means, that first, an ethylene polymer having a lower average molecular weight is produced and then, in the presence of the lower molecular weight ethylene polymer, an ethylene polymer having a higher average molecular weight is produced.
The idea of the present invention can be realized with any kind of ethylene poly-merization catalyst, such as a chromium catalyst, a Ziegler-Natta catalyst or a group 4 transition metallocene catalyst. According to one embodiment of the present invention, said blend forming the multimodal ethylene polymer is the product of a polymerization process in which said first step and/or said second step is performed in the presence of a catalyst system comprising a procatalyst based on a tetravalent titanium compound, such as a TiClq,/MgC12/optional inert carrier/optional internal electron donor procatalyst, and a cocatalyst based on an organoaluminum compound, preferentially a R3AIUoptional external electron donor procatalyst wherein R is a C1-C10 alkyl. Typical catalyst systems are e.g. prepared according to W091/12182 and W095135323. A preferential single site polymerization catalyst system is that based on a group 4(IL'PAC 1990) metal metallocene and alurnoxane.
When performing said polvmerization process comprising at least two steps, one or more catalyst systems, which may be the same or different, can be used. It is preferential, if said blend is the product of said polymerization process, in which said catalyst system is added to said first step and the same catalyst system is used at least in said second step.
The most convenient way to regulate the molecular weight during the multistep polymerization of the present invention is to use hydrogen, which acts as a chain-transfer agent by intervening in the insertion step of the polymerization mechanism.
Hydrogen may be added in suitable amounts to any step of the multistep poly-merization. However, it is preferential that in said first step a hydrogen amount is used, leading to a melt flow rate MFR12 of said first ethylene polymer of from g/10 nmin. to 2000 g/min., most preferentially from 100 g/ 10 min. to 1000 g/
10 min., provided that said first step is performed before said second step.
It is prior known to prepare multimodal and especially bimodal olefin polymers in two or more polymerization reactors in series. Such processes are exemplified by EP
040992, EP 04179.fi, EP 022376 and W092/12182 which concern the preparation of the multimodal ethylene polymers for the claimed coating material. According to these references each of said polymerization steps can be performed in liquid phase, slurry or gas phase.
According to the present invention, it is preferential to perform said polymerization steps as a combination of slurry polymerization and gas phase polymerization.
Preferentially said first step is a slurry polymerization and said second step a gas phase polymerization.
The slurry polymerization is preferentially performed in a so called loop reactor.
The gas phase polymerization is performed in a gas phase reactor. The poly-merization steps can optionally be preceded by a prepolymerization, whereby up to 20% by weight and preferentially 1-10% by weight of the total ethylene polymer amount is formed.
Above, the use of hydrogen to regulate the molecular weight of the ethylene poly-mers is mentioned. The properties of the ethylcne polymers can also be modified by adding a small amount of a-olefin to any of said polyrnerizatio.n steps.
According to one embodiment of the present invention, said first ethylene polymer has a C3-a-olefin repeating unit content of from 0 to 10% by weight of said first ethylene polymer. Preferentially, in said second ethylene polymer, the C3-ClO a-olefin, such as 1-butene or 1-hexene, repeating unit content is from 1 to 25% by weight, most preferentially 2 to 15% by weight, of said second ethylene polymer.
When using only two steps in said polyznerization process, the ratio between the first produced ethylene polymer having the MFR12 defined above, and the second produced ethylene polymer, having a lower MFR, is between 20:80 and 80:20, preferentially between 20:80 and 60:40.
The above mentioned polymerization conditions of the different steps can be coordinated 5 so that the blend produced is most suitable for the coating of a solid substrate. Thus, the following preferential properties of said multimodal ethylene polymer blend can be achieved.
In one aspect, there is provided a use of a polymer composition for melt coating of a rigid pipe, pipe fitting or profile, characterized in that the composition has an environmental stress cracking resistance (ESCR, F20, ASTM 1693) of at least 100 h and comprises a multimodal ethylene polymer, which contains from 80 to 100% by weight of ethylene repeating units and from 0 to 20% by weight of C3-C10 a-olefin repeating units, has a density of between 0.915 g/cm3 and 0.955 g/cm3, and is a blend of at least a first ethylene polymer having a first average molecular weight corresponding to a melt flow rate MFR12 of from 50 g/10 min. to 2000 g/10 min. and a first molecular weight distribution and a second ethylene polymer having a second average molecular weight, which is higher than the first average molecular weight, and a second molecular weight distribution, the ratio between the first and second ethylene polymer being from 80:20 to 20:80, the blend having a third average molecular weight corresponding to a melt flow rate MFR32 of from 0.1 g/10 min. to 20 g/10 min. and a third molecular weight distribution. The pipe, pipe fitting or profile may be a rigid iron pipe, iron pipe fitting, iron profile, a rigid steel pipe, steel pipe fitting or steel profile.
In another aspect, there is provided a use of a composition characterized in that the blend is the product of a polymerization process comprising at least two steps in which the first ethylene polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a first step and the second ethylene polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a second step, the steps being performed in any order, the ethylene polymer of each step being present in the following step or steps.
In another aspect, there is provided a use of a composition characterized in that the blend 5a is the product of the polymerization process in which the first step and/or the second step is performed in the presence of a catalyst system comprising a procatalyst based on the tetravalent titanium compound procatalyst TiC14/1VIgC12/optional inert carrier/optional internal electron donor, and a cocatalyst based on a R3Al/optional external electron donor wherein R is a C1-Clo alkyl.
In another aspect, there is provided a use of a composition characterized in that the blend is the product of the polymerization process, in which the catalyst system is added to the first step and the same catalyst system is used at least in the second step.
In another aspect, there is provided a use of a composition characterized in that the blend is the product of the polymerization process, in the first step of which an amount of the chain transfer agent hydrogen, is used, which gives a melt flow rate MFR12 for the first ethylene polymer of from 100 g/10 min. to 1000 g/10 min., provided that step 1 is performed first.
In another aspect, there is provided use of a composition characterized in that the blend is the product of the polymerization process, in which the first step and the second step are performed as a slurry polymerization, gas phase polymerization or a combination thereof.
In another aspect, there is provided a use of a composition characterized in that in the blend is the product of the polymerization process, in which the first step is performed as a slurry polymerization, and the second step is performed as a gas phase polymerization.
In another aspect, there is provided a use of a composition characterized in that in the first ethylene polymer, the C3-Clo a-olefin repeating unit content is from 0 to 10%
by weight of the first ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that in the second ethylene polymer, the C3-Clo a-olefin repeating unit content is from 1 to 25% by weight and from 2 to 15% by weight, of the second ethylene polymer.
5b In another aspect, there is provided a use of a composition characterized in that in the second ethylene polymer, the C3-Clo a-olefin repeating unit content is from 2 to 15% by weight, of the second ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that in the blend, the ratio between the first ethylene polymer and the second ethylene polymer is between 20:80 and 60:40.
In another aspect, there is provided a use of a composition characterized in that the C3-Clo cc-olefin repeating unit content of the blend is from 0.2 to 20% by weight.
In another aspect, there is provided a use of a composition characterized in that the C3-Clo oc-olefin content is from 0.5 to 15% by weight, of the blend.
In another aspect, there is provided a use of a composition characterized in that the flow rate ratio FRR321i5 of the blend is between 10 and 50, the molecular weight distribution curve showing several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material.
In another aspect, there is provided a use of a characterized in that the blend is a mechanical mixture of at least the first ethylene polymer and the second ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that the blend is a mechanical melt mixture of the first ethylene polymer and the second ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that the ratio between the first ethylene polymer and the second ethylene polymer is between 20:80 and 60:40.
In another aspect, there is provided a use of a composition characterized in that the melt flow ratio MFRIZ of the first ethylene polymer is from 100 to 1000 g/10 min.
5c In another aspect, there is provided a use of a composition characterized in that the melt flow ratio MFR221 of the second ethylene polymer is from 0.05 to 50 g/10 min.
In another aspect, there is provided a use of a composition characterized in that the first ethylene polymer has a C3-Clo a-olefin repeating unit content of from 0 to 10%
by weight of the first ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that the second ethylene polymer has a C3-Clo a-olefin repeating unit content of from 1 to 25%
by weight of the second ethylene polymer.
In another aspect, there is provided a use of a composition characterized in that the melt flow ratio MFR32 of the blend is between 0.1 and 50 g/10 min., preferentially between 0.1 and 20 g/10 min.
In another aspect, there is provided a use of a composition characterized in that the C3-Clo a-olefin repeating unit content of the blend is from 0.2 to 20% by weight.
In another aspect, there is provided a use of a composition characterized in that the flow rate ratio FRR321i5 of the blend is between 10 and 50, the molecular weight distribution curve showing several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material.
In another aspect, there is provided a use of a composition, characterized in that the blend is a blend which has been treated in a tailoring step comprising heating, melt processing and subjecting to controlled free radical reactions to give a molecular weight, which is at least as high as the molecular weight of the untreated blend, and a molecular weight distribution, which is broader than the molecular weight distribution of the untreated blend.
In another aspect, there is provided a use of a composition characterized in that the blend is a blend which has been treated in the tailoring step so that during the tailoring step, the 5d relative decrease in the ratio, -( MFR3' 5 - MFR35):MFR35, is from 10 to 80%, wherein MFRY 5 is the melt index of the blend after the tailoring step.
In another aspect, there is provided a use of a composition characterized in that the blend is a blend which has been treated in the tailoring step so that during the tailoring step, the relative broadening of the molecular weight distribution expressed as +( FRR3'21i5 +FRR321i5): FRR321i5 is from 10 to 80%, wherein FRR3' 21i5 is the flow rate ratio of the blend after the tailoring step.
In another aspect, there is provided a use of a composition characterized in that it has an environmental stress cracking resistance (ESCR, F20) of at least 500 h. In another aspect, there is provided a use of a composition characterized in that it has an environmental stress cracking resistance of at least 1000 h.
In another aspect, there is provided a use of a composition characterized in that the composition is used for coating of a substrate comprising an iron or a steel pipe, a primer, covering the iron or steel pipe, and a coupling agent, covering the primer, wherein the primer may be an epoxy lacquer and the coupling agent may be carboxy modified polyethylene.
According to a preferred embodiment of the present invention, the melt flow rate MFR32 of said blend is between 0.1 and 50 g/10 min., more preferably between 0.1 and 20 g/10 min. According to a preferred embodiment, the C3-lo a-olefin repeating unit content of said blend is from 0.2 to 20% by weight, more preferably from 0.5 to 15% by weight, of said blend. According to a preferred embodiment, the flow rate ratio FRR321i5 of said blend is between 10 and 50, more preferentially between 15 and 40. Thereby, it is advantageous if the molecular weight distribution corresponding to said flow rate ratio shows several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material.
As was described above, the multimodal ethylene polymer according to the invention can be produced in a polymerizing process having at least two steps leading to different 5e average molecular weights. According to another important embodiment of the invention, the multimodal ethylene polymer can be produced by mixing at least two ethylene polymers having different average molecular weights. In the latter case, said blend is a mechanical mixture of at least said first ethylene polymer and said second ethylene polymer, preferentially a mechanical mixture of said first ethylene polymer and said second ethylene polymer.
When mixing two ethylene polymers of different average molecular weight, the mixing is generally a melt mixing in a melt processing apparatus like a compounder and an extruder.
The product is then a mechanical melt mixture of at least said first ethylene polymer and said second ethylene polymer. Preferentially there are only two ethylene polymers so that the mechanical melt mixture is a mixture of said first ethylene polymer and said second ethylene polymer. The preferable ratio between said first ethylene polymer and said second ethylene polymer is between 20:80 and 80:20, most preferably between 20:80 and 60:40.
When feeding the first ethylene polymer to the mixing step, the melt flow ratio MFR12 of the first ethylene polymer is preferentially from 50 to 2000 g/10 min., .
most preferentially from 100 to 1000 g/ 10 min. When feeding at least said second ethylene polymer to the mixing step, its or their melt flow ratio MFR2, etc=Z1 is preferentially from 0.05 to 50 g/10 min., most preferentially from 0.10 to 20 g/IO
=
min.
In its most wide scope, the present invention relates to a coating composition comprising any multimodal ethylene polymer. This means, that the different ethylene polymers which can be used can have the monomer composition of a homopolymer or a copolymer. Preferentially said first ethylene polymer has a C I 0 a-olefin repeating unit content of 0.0 to 10% by weight, calculated from the weight of said ethylene polymer.
Usually at least one ethylene polymer component of said blend is an ethylene copolymer containing a small amount of another a-olefm. Preferentially, said second ethylene polymer has a C;-CIO a-olefm, preferentially 1-butene or 1-hexene, repeating unit content of from 1.0 to 25% by weight and most preferentially from 2.0 to 15% by weight. Typical other comonomers are 4-methyl-l-pentene and 1-octene. When a blend of more than two ethylene polymer components is used, the further ethylene polymer components can be either homopolymers or copolymers.
Conclusively, in the embodiment where the coating composition multimodal ethylene polymer is prepared by mixing at least a first ethylene polymer and a second ethylene polymer, the proportion of the first ethylene polymer and the second, etc., ethylene polymer, the MFR I, MFR2, etc. of said ethylene polymers and C3-C10 a-olefm repeating unit content of said ethylene polymers are preferentially such that the MFR32 of the blend obtained is between 0.1 and 50 g/10 min., preferentially between 0.1 and 20 g/l0 min. Correspondingly, but independently, the C3-CIO a-olefm repeating unit content of the said blend is from 0.2 to 20% by weight, preferentially from 0.5 to 15% by weight. The flow rate ratio FRR321/5 of said blend is between 10 and 50, preferentially between 15 and 40.
The molecular weight distribution curve shows either several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material. It was found, that, although the melt flow ratios, the comonomer repeating unit content and the flow rate ratio were essentially the same as in known mono-modal products, the mere fact that the ethylene polymer was multimodal, i.e.
was the blend of different molecular weight fractions, rendered it totally superior e.g.
with respect to the processability measured as winding speed and the environmental stress cracking resistance.
Above, a multimodal ethylene polymer suitable for a coating composition has been described, which is merely the product of multistep polymerization or mixing.
The invention also relates to a coating composition, prepared by a combination of multistep polymerization and mixing, e.g. by polymerizing ethylene in two or more steps and mixing the product with one or more ethylene polymers. Also, the finished polymerization or mixing product can further be treated to modify its average molecular weight and molecular weight distribution.
According to one embodiment of the present invention said blend is a blend which has been treated in a tailoring step comprising heating, melt processing and subjecting of a multimodal ethylene polymer to controlled radical reactions to give a molecular weight, which is at least as high as the molecular weight of the untreated blend, and a molecular weight distribution, which is broader than the molecular weight distribution of the untreated blend.
Preferentially a said tailoring step leads to a relative decrease in the melt flow ratio MFR5, -(MFR3'5 - MFR35): MFR35, is from 5 to 100%, preferentially from 10 to 80%, wherein MFR3'5 is the melt index of said blend after said tailoring step.
The upper limits are not to be interpreted as limitations, but it has only a descriptive function, which is based on the experimental results obtained in connection with the present invention. Anyhow, it appears that the melt viscosity decreases by several tens of percent, which meant that the controlled free radical reactions essentially lead to the combination of radical fragments into larger ethylene polymer molecules than before the controlled free radical reactions.
Perhaps even more important is the effect of the tailoring step on the molecular weight distribution expressed as the flow rate ratio of the blend. According to one embodiment of the invention, the relative broadening of the molecular weight distribution expressed as +(FRR3'21/5-FRR321/5):FRR321/5 is from 5 to 100%, preferentially from 10 to 80%, wherein FRR3'21/5 is the flow rate ratio of said blend after said tailoring step.
The free radical reactions of said tailoring step can be effected in many ways.
Firstly, free radicals may be generated from initiators in diverse ways, among which thermal or photochemical intermolecular bond cleavage, redox reactions, and photochemical hydrogen abstraction are the most common, but other processes such as the use of y-radiation or electron beams find application. Free radicals can also be generated by means of reaction of the ethylene polymer blend by means of thermal decomposition with or without the presence of oxygen. Thermal treatment is a suitable method, especially if unstabilized or partly stabilized polyethylene is used or if the used ethylene polymer is destabilized during the treatment.
One of the main obstacles for using ethylene polymers as coating materials has up to now been an unsatisfying environmental stress cracking resistance. Another obstacle has been the poor melt coating processability of ethylene polymers.
In the present invention, the finding that multimodal ethylene polymer has a totally superior environmental stress cracking resistance and melt coating processability, has lead to a new coating material which is the technical and commercial consequence of said fmding. Thus the coating composition of the present invention preferentially has an environmental stress cracking resistance (ESCR, F20) (ASTM
1693/A, 10% Igepal) of at least 100 h, more preferentially at least 500 h, yet more preferentially at least 1000 h and most preferentially 2000 h.
In principle the claimed coating composition is suitable for any solid substrate such as a particle, powder, a corn, a grain, a granula, granulate, an aggregate, a fiber, a filln., a bladder, a blister, a coat, a coating, a cover, a diaphragm, a membrane, a skin, a septum, a serving, a foil, a web, a cloth, a fabric, a canvas, a textile, a tissue, a sheet, a board, a cardboard, a carton, a fiber board, a paperboard, a pasteboard, a disc, a laminate, a layer, a planchette, a plate, a slab, a slice, a spacer, a wafer, a tape, a belt, a lace, a ribbon, a slip, a string, a strip, a band, a rope, a filament, a file, a fillet, a thread, a wire, a cable wire, a wire cable, a wire rope, a yarn, a cable, a conduit, a cord, a duct, a line, a rope, a hawser, a body, a block, a part, a moulding, a workpiece, a fabricated shape, a form part, a formed piece, a mould shape, a shaped piece, a special casting, a special piece, a bar, a lever, a boom, a pole, a rod, a shaft, a shank, a spoke, a staff, an arm, a gripe, a helve, a pin, a rein, a spindle, a staff, a stalk, a stem, a tube, a hose, a hose pipe, a sleeve, a barrel, a canal, a pipe, a spout, a valve, a profile.
Preferentially the claimed coating composition is a coating material for a solid =
substrate made of metal such as iron, steel, noble metals, metal alloys, composition metals, hard metals, cintered metals, cermets, or from non-metals such as concrete, cement, mortar, plaster, stone, glass, porcelain, ceramics, refractory materials, enamel, wood, bark, cork, paper and paperboard, textile, leather, rubber and caoutchouc, plastics, and bituminous materials.
Most preferentially the claimed coating composition is a coating material for a rigid solid substrate, preferentially a rigid pipe, a rigid pipe fitting or a rigid profile, most preferentially an iron or steel pipe, pipe fitting or profile. In more detail, such a pipe is an iron or steel pipe, having a primer like an epoxy lacquer covering the steel surface and a coupling agent like carboxy modified polyethylene covering said primer. The claimed coating composition is then attached to the layer of carboxy modified polyethylene.
In addition to the above described coating composition, the present invention also relates to the process for the preparation of said coating composition, thereby the claimed process is as described above.
The invention also relates to the use of a coating composition according to the above description or prepared by the claimed process for the coating of a solid substrate such as a particle, powder, a corn, a grain, a granula, granulate, an aggregate, a fiber, a film, a bladder, a blister, a coat, a coating, a cover, a diaphragm, a membrane, a skin, a septum, a serving, a foil, a web, a cloth, a fabric, a canvas, a textile, a tissue, a sheet, a board, a cardboard, a carton, a fiber board, a paperboard, a pasteboard, a disc, a laminate, a layer, a planchette, a plate, a slab, a slice, a spacer, a wafer, a tape, a belt, a lace, a ribbon, a slip, a string, a strip, a band, a rope, a filament, a file, a fillet, a thread, a wire, a cable wire, a wire cable, a wire rope, a yarn, a cable, a conduit, a cord, a duct, a line, a rope, a hawser, a body, a block, a part, a moulding, a workpiece, a fabricated shape, a form part, a formed piece, a mould shape, a shaped piece, a special casting, a special piece, a bar, a lever, a boom, a pole, a rod, a shaft, a shank, a spoke, a staff, an arm, a gripe, a helve, a pin, a rein, a spindle, a staff, a stalk, a stem, a tube, a hose, a hose pipe, a sleeve, a barrel, a canal, a pipe, a spout, a valve, a profile.
Preferentially the use is directed to the coating of a solid substrate made of metal such as iron, steel, noble metals, metal alloys, composition metals, hard metals, cintered metals, cermets, or of non-metals such as concrete, cement, mortar, plaster, stone, glass, porcelain, ceramics, refl-actory materials, enamel, wood, bark, cork, paper and paperboard, textile, leather, rubber and caoutchouc, plastics, and bituminous materials.
The use of the invention is most preferably directed to the coating a rigid solid =
substrate, preferentially a rigid pipe, a rigid pipe fitting or a rigid profile, most preferentially an iron or steel pipe, pipe fitting or profile. In the case of a coating a metal pipe like an iron or steel pipe with the coating composition according to the 5 invention, the pipe is preferentially covered with a primer like an epoxy lacquer and the primer layer is then covered with a coupling agent layer like carboxy modified polyethylene, whereby the coating composition is deposited on said coupling agent layer.
Above, a multimodal ethylene polymer suitable for a coating composition has been described, which is merely the product of multistep polymerization or mixing.
The invention also relates to a coating composition, prepared by a combination of multistep polymerization and mixing, e.g. by polymerizing ethylene in two or more steps and mixing the product with one or more ethylene polymers. Also, the finished polymerization or mixing product can further be treated to modify its average molecular weight and molecular weight distribution.
According to one embodiment of the present invention said blend is a blend which has been treated in a tailoring step comprising heating, melt processing and subjecting of a multimodal ethylene polymer to controlled radical reactions to give a molecular weight, which is at least as high as the molecular weight of the untreated blend, and a molecular weight distribution, which is broader than the molecular weight distribution of the untreated blend.
Preferentially a said tailoring step leads to a relative decrease in the melt flow ratio MFR5, -(MFR3'5 - MFR35): MFR35, is from 5 to 100%, preferentially from 10 to 80%, wherein MFR3'5 is the melt index of said blend after said tailoring step.
The upper limits are not to be interpreted as limitations, but it has only a descriptive function, which is based on the experimental results obtained in connection with the present invention. Anyhow, it appears that the melt viscosity decreases by several tens of percent, which meant that the controlled free radical reactions essentially lead to the combination of radical fragments into larger ethylene polymer molecules than before the controlled free radical reactions.
Perhaps even more important is the effect of the tailoring step on the molecular weight distribution expressed as the flow rate ratio of the blend. According to one embodiment of the invention, the relative broadening of the molecular weight distribution expressed as +(FRR3'21/5-FRR321/5):FRR321/5 is from 5 to 100%, preferentially from 10 to 80%, wherein FRR3'21/5 is the flow rate ratio of said blend after said tailoring step.
The free radical reactions of said tailoring step can be effected in many ways.
Firstly, free radicals may be generated from initiators in diverse ways, among which thermal or photochemical intermolecular bond cleavage, redox reactions, and photochemical hydrogen abstraction are the most common, but other processes such as the use of y-radiation or electron beams find application. Free radicals can also be generated by means of reaction of the ethylene polymer blend by means of thermal decomposition with or without the presence of oxygen. Thermal treatment is a suitable method, especially if unstabilized or partly stabilized polyethylene is used or if the used ethylene polymer is destabilized during the treatment.
One of the main obstacles for using ethylene polymers as coating materials has up to now been an unsatisfying environmental stress cracking resistance. Another obstacle has been the poor melt coating processability of ethylene polymers.
In the present invention, the finding that multimodal ethylene polymer has a totally superior environmental stress cracking resistance and melt coating processability, has lead to a new coating material which is the technical and commercial consequence of said fmding. Thus the coating composition of the present invention preferentially has an environmental stress cracking resistance (ESCR, F20) (ASTM
1693/A, 10% Igepal) of at least 100 h, more preferentially at least 500 h, yet more preferentially at least 1000 h and most preferentially 2000 h.
In principle the claimed coating composition is suitable for any solid substrate such as a particle, powder, a corn, a grain, a granula, granulate, an aggregate, a fiber, a filln., a bladder, a blister, a coat, a coating, a cover, a diaphragm, a membrane, a skin, a septum, a serving, a foil, a web, a cloth, a fabric, a canvas, a textile, a tissue, a sheet, a board, a cardboard, a carton, a fiber board, a paperboard, a pasteboard, a disc, a laminate, a layer, a planchette, a plate, a slab, a slice, a spacer, a wafer, a tape, a belt, a lace, a ribbon, a slip, a string, a strip, a band, a rope, a filament, a file, a fillet, a thread, a wire, a cable wire, a wire cable, a wire rope, a yarn, a cable, a conduit, a cord, a duct, a line, a rope, a hawser, a body, a block, a part, a moulding, a workpiece, a fabricated shape, a form part, a formed piece, a mould shape, a shaped piece, a special casting, a special piece, a bar, a lever, a boom, a pole, a rod, a shaft, a shank, a spoke, a staff, an arm, a gripe, a helve, a pin, a rein, a spindle, a staff, a stalk, a stem, a tube, a hose, a hose pipe, a sleeve, a barrel, a canal, a pipe, a spout, a valve, a profile.
Preferentially the claimed coating composition is a coating material for a solid =
substrate made of metal such as iron, steel, noble metals, metal alloys, composition metals, hard metals, cintered metals, cermets, or from non-metals such as concrete, cement, mortar, plaster, stone, glass, porcelain, ceramics, refractory materials, enamel, wood, bark, cork, paper and paperboard, textile, leather, rubber and caoutchouc, plastics, and bituminous materials.
Most preferentially the claimed coating composition is a coating material for a rigid solid substrate, preferentially a rigid pipe, a rigid pipe fitting or a rigid profile, most preferentially an iron or steel pipe, pipe fitting or profile. In more detail, such a pipe is an iron or steel pipe, having a primer like an epoxy lacquer covering the steel surface and a coupling agent like carboxy modified polyethylene covering said primer. The claimed coating composition is then attached to the layer of carboxy modified polyethylene.
In addition to the above described coating composition, the present invention also relates to the process for the preparation of said coating composition, thereby the claimed process is as described above.
The invention also relates to the use of a coating composition according to the above description or prepared by the claimed process for the coating of a solid substrate such as a particle, powder, a corn, a grain, a granula, granulate, an aggregate, a fiber, a film, a bladder, a blister, a coat, a coating, a cover, a diaphragm, a membrane, a skin, a septum, a serving, a foil, a web, a cloth, a fabric, a canvas, a textile, a tissue, a sheet, a board, a cardboard, a carton, a fiber board, a paperboard, a pasteboard, a disc, a laminate, a layer, a planchette, a plate, a slab, a slice, a spacer, a wafer, a tape, a belt, a lace, a ribbon, a slip, a string, a strip, a band, a rope, a filament, a file, a fillet, a thread, a wire, a cable wire, a wire cable, a wire rope, a yarn, a cable, a conduit, a cord, a duct, a line, a rope, a hawser, a body, a block, a part, a moulding, a workpiece, a fabricated shape, a form part, a formed piece, a mould shape, a shaped piece, a special casting, a special piece, a bar, a lever, a boom, a pole, a rod, a shaft, a shank, a spoke, a staff, an arm, a gripe, a helve, a pin, a rein, a spindle, a staff, a stalk, a stem, a tube, a hose, a hose pipe, a sleeve, a barrel, a canal, a pipe, a spout, a valve, a profile.
Preferentially the use is directed to the coating of a solid substrate made of metal such as iron, steel, noble metals, metal alloys, composition metals, hard metals, cintered metals, cermets, or of non-metals such as concrete, cement, mortar, plaster, stone, glass, porcelain, ceramics, refl-actory materials, enamel, wood, bark, cork, paper and paperboard, textile, leather, rubber and caoutchouc, plastics, and bituminous materials.
The use of the invention is most preferably directed to the coating a rigid solid =
substrate, preferentially a rigid pipe, a rigid pipe fitting or a rigid profile, most preferentially an iron or steel pipe, pipe fitting or profile. In the case of a coating a metal pipe like an iron or steel pipe with the coating composition according to the 5 invention, the pipe is preferentially covered with a primer like an epoxy lacquer and the primer layer is then covered with a coupling agent layer like carboxy modified polyethylene, whereby the coating composition is deposited on said coupling agent layer.
10 In the following, a few examples are presented to illuminate the present invention.
In the examples, bimodal polyethylene was prepared and tested. The preparations were as follows.
Example 1 Bimodal polyethene 41 was polymerized with a Ziegler-Natta -type catalyst prepared according to Fl 942945 in one loop and one gas phase reactor which were operated in series. Ethene was polymerized in the presence of hydrogen in the loop reactor resulting in MFR2=468. Ethene was polymerized with 1-butene and hydrogen in the gas phase. The production rate split of reactors was 45%/55%.
The final product MFR2=I.3, FRR21/5=18 and density 941 kg/m3.
Bimodal polyethene #2 was polymerized with a Ziegler-Natta -type catalyst in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in presence of hydrogen in the loop reactor resulting in MFR2=444.
Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor.
The production rate split of reactors was 40%/60%. The final product MFR2=1.3, FRR21/5=16 and density 940 kg/m3.
Reference material was conunercial low shrinkage material HE6066 of Borealis.
Example 2 Bimodal polyethene #3 was polymerized with a Ziegler-Natta -type catalyst prepared according to Fl 942949 in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in presence of hydrogen in the loop reactor resulting in MFR2=492. Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor. The production rate split of reactors was 45%/55%. The fmal product MFR2=0.4, FRR21/5=21 and density 941 kg/m3.
Bimodal polyethene #4 was polymerized with a Ziegler-Natta -type catalyst in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in presence of hydrogen in the loop reactor resulting in MFR2=53.
Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor.
The production rate split of reactors was 44%/56%. The final product MFR2=0.3, FRR21/5=17 and density 941 kg/m3.
Reference material was commercial steel pipe coating material HE6060 of Borealis.
Example 3 Bimodal polyethene #5 was polymerized with a Ziegler-Natta -type catalyst prepared according to FI 942949 in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in the presence of hydrogen in the loop reactor resulting in MFR2=384. Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor. The production rate split of reactors was 45%/55%. The fmal product MFR2=0.5, FRR21/5=19 and base resin density 944 kg/m3.
Bimodal polyethene #6 was polymerized with a Ziegler-Natta -type catalyst prepared according to FI 942949 in one loop and one gas phase reactor which are operated in series. The catalyst was prepolymerized before feeding into the loop reactor. The prepolymerization degree was 62 g/g. Ethene was polymerized in the presence of hydrogen in the loop reactor resulting in MFR2=274. Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor. The production rate split of loop and gas phase reactors was 48%/52%. The fmal product MFR2=0.5, FRR21/5=20 and base resin density 945 kg/m3.
Bimodal polyethene #7 was polymerized with a Ziegler-Natta -type catalyst prepared according to Fl 942949 in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in the presence of hydrogen and 1-butene in the loop reactor resulting in MFR2=230 and density 943 kg/m3. Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor. The production rate split of reactors was 43%/57%. The fmal product MFR2=0.5, FRR21/5=19 and base resin density 927 kg/m3.
In the examples, bimodal polyethylene was prepared and tested. The preparations were as follows.
Example 1 Bimodal polyethene 41 was polymerized with a Ziegler-Natta -type catalyst prepared according to Fl 942945 in one loop and one gas phase reactor which were operated in series. Ethene was polymerized in the presence of hydrogen in the loop reactor resulting in MFR2=468. Ethene was polymerized with 1-butene and hydrogen in the gas phase. The production rate split of reactors was 45%/55%.
The final product MFR2=I.3, FRR21/5=18 and density 941 kg/m3.
Bimodal polyethene #2 was polymerized with a Ziegler-Natta -type catalyst in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in presence of hydrogen in the loop reactor resulting in MFR2=444.
Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor.
The production rate split of reactors was 40%/60%. The final product MFR2=1.3, FRR21/5=16 and density 940 kg/m3.
Reference material was conunercial low shrinkage material HE6066 of Borealis.
Example 2 Bimodal polyethene #3 was polymerized with a Ziegler-Natta -type catalyst prepared according to Fl 942949 in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in presence of hydrogen in the loop reactor resulting in MFR2=492. Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor. The production rate split of reactors was 45%/55%. The fmal product MFR2=0.4, FRR21/5=21 and density 941 kg/m3.
Bimodal polyethene #4 was polymerized with a Ziegler-Natta -type catalyst in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in presence of hydrogen in the loop reactor resulting in MFR2=53.
Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor.
The production rate split of reactors was 44%/56%. The final product MFR2=0.3, FRR21/5=17 and density 941 kg/m3.
Reference material was commercial steel pipe coating material HE6060 of Borealis.
Example 3 Bimodal polyethene #5 was polymerized with a Ziegler-Natta -type catalyst prepared according to FI 942949 in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in the presence of hydrogen in the loop reactor resulting in MFR2=384. Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor. The production rate split of reactors was 45%/55%. The fmal product MFR2=0.5, FRR21/5=19 and base resin density 944 kg/m3.
Bimodal polyethene #6 was polymerized with a Ziegler-Natta -type catalyst prepared according to FI 942949 in one loop and one gas phase reactor which are operated in series. The catalyst was prepolymerized before feeding into the loop reactor. The prepolymerization degree was 62 g/g. Ethene was polymerized in the presence of hydrogen in the loop reactor resulting in MFR2=274. Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor. The production rate split of loop and gas phase reactors was 48%/52%. The fmal product MFR2=0.5, FRR21/5=20 and base resin density 945 kg/m3.
Bimodal polyethene #7 was polymerized with a Ziegler-Natta -type catalyst prepared according to Fl 942949 in one loop and one gas phase reactor which are operated in series. Ethene was polymerized in the presence of hydrogen and 1-butene in the loop reactor resulting in MFR2=230 and density 943 kg/m3. Ethene was polymerized with 1-butene and hydrogen in the gas phase reactor. The production rate split of reactors was 43%/57%. The fmal product MFR2=0.5, FRR21/5=19 and base resin density 927 kg/m3.
The main end product properties of examples 1-2 are shown in tables 1 and 2.
Table 1 shows a comparison between the coating materials # 1 and #2 according to the invention and a commercial material (HE6066). As can be seen from table 1, the enviromnental stress cracking resistance and winding speed of the coating material according to the invention are outstanding comparing to corresponding conventional coating material.
Table I Properties of bimodal polyethene materials compared to existing commercial materials MATERIAL Pol ethene # 1 Pol ethene #2 HE6066 MFR / 10 min. 1. 3 1.3 2.0 Mw Mw/Mn DENSITY k m3 941 940 941 ESCR, F20 >2000 >2000 106 Shrink., 100 C/24 h% 1 0.45 0.6 1 Tensile at yield (MPa) 21 21 20 Winding speed, 42 42 6 max m/min. 2 1 Cable line 210 C and 75 m/min.
2 Demag coating line: screw 0 45 mm, L/D=24, die width = 450 mm, die gap =
0,5 mm.
Table 2 shows a comparison between coating materials #3 and #4 according to the present invention and a corresponding commercial coating material (HE6060). As can be seen from table 2, the materials according to the present invention are superior over conventional coating materials also at lower MFR2 level.
Table 1 shows a comparison between the coating materials # 1 and #2 according to the invention and a commercial material (HE6066). As can be seen from table 1, the enviromnental stress cracking resistance and winding speed of the coating material according to the invention are outstanding comparing to corresponding conventional coating material.
Table I Properties of bimodal polyethene materials compared to existing commercial materials MATERIAL Pol ethene # 1 Pol ethene #2 HE6066 MFR / 10 min. 1. 3 1.3 2.0 Mw Mw/Mn DENSITY k m3 941 940 941 ESCR, F20 >2000 >2000 106 Shrink., 100 C/24 h% 1 0.45 0.6 1 Tensile at yield (MPa) 21 21 20 Winding speed, 42 42 6 max m/min. 2 1 Cable line 210 C and 75 m/min.
2 Demag coating line: screw 0 45 mm, L/D=24, die width = 450 mm, die gap =
0,5 mm.
Table 2 shows a comparison between coating materials #3 and #4 according to the present invention and a corresponding commercial coating material (HE6060). As can be seen from table 2, the materials according to the present invention are superior over conventional coating materials also at lower MFR2 level.
Table 2 Properties of bimodal polyethene materials compared to existing commercial materials, MFR2 - 0.3 g/10 min MATERIAL Polyethene #3 Polyethene #4 HE6060 MFR2 / 10 min. 0.4 0.3 0.29 MFR 10 min. 1.7 1.2 1.3 MFR21 10 min. 34 20 22.0 Mw 217 000 Mw/Mn 13.1 DENSITY k m3 941 941 937.3 ESCR, F20 (h) >2000 >2000 Shrink., 100 C/24 h% 1 0.9 1.1 -Tensile at yield (MPa) 21 23 Winding speed, 37 40 4-10 max m/min. 2 1 Cable line 210 C and 75 m/min.
2 Demag coating line: screw 0 45 mm, L/D=24, die width = 450 mm, die gap =
0,5 mm.
Table 3 Processability behaviour of reference material HE6060 and Polyethene #5, #6 and #7 were tested on Barmag 0 60 mm, L/D extruder having 240 mm wide flat die with die gap 1.5 mm. Extruder screw speed was 85 rpm.
MATERIAL Melt temp., C Current, A Pressure, bar HE6060 ref. 270 42 379 Pol ethene #5 266 38 341 Pol ethene #6 269 37 342 Pol ethene #7 256 42 368 One can see that in spite of higher melt temperature, the power consumption and die pressure of reference material was high indicating worse processability compared to materials related in this invention.
A very important charasteristics of coating material is maximum winding speed of material and thus maximum output rate of the extruder. Table 4 shows that at least 67% higher line speed can be ahieved with materials of this invention compared to reference material HE6060. Note that further increase of winding speed from 25 m/min is limited by equipment not by break off of Polyethene #5, #6 and #7 films.
Table 4 Maximum winding speed of example 3 materials on Barmag 0 60 mm, L/D=24 extruder. Die width was 240 mm and die gap 1.5 mm. Cast film was applied on the 0 150 mm epoxy/ahdesive precoated steel pipe.
MATERIAL Maximum winding speed, Output, kg/m3 m/min HE6060, reference 15 36 Pol ethene #5 25 >_ 51.8 Polyethene #6 25 50.9 Polyethene #7 >_ 25 > 54
2 Demag coating line: screw 0 45 mm, L/D=24, die width = 450 mm, die gap =
0,5 mm.
Table 3 Processability behaviour of reference material HE6060 and Polyethene #5, #6 and #7 were tested on Barmag 0 60 mm, L/D extruder having 240 mm wide flat die with die gap 1.5 mm. Extruder screw speed was 85 rpm.
MATERIAL Melt temp., C Current, A Pressure, bar HE6060 ref. 270 42 379 Pol ethene #5 266 38 341 Pol ethene #6 269 37 342 Pol ethene #7 256 42 368 One can see that in spite of higher melt temperature, the power consumption and die pressure of reference material was high indicating worse processability compared to materials related in this invention.
A very important charasteristics of coating material is maximum winding speed of material and thus maximum output rate of the extruder. Table 4 shows that at least 67% higher line speed can be ahieved with materials of this invention compared to reference material HE6060. Note that further increase of winding speed from 25 m/min is limited by equipment not by break off of Polyethene #5, #6 and #7 films.
Table 4 Maximum winding speed of example 3 materials on Barmag 0 60 mm, L/D=24 extruder. Die width was 240 mm and die gap 1.5 mm. Cast film was applied on the 0 150 mm epoxy/ahdesive precoated steel pipe.
MATERIAL Maximum winding speed, Output, kg/m3 m/min HE6060, reference 15 36 Pol ethene #5 25 >_ 51.8 Polyethene #6 25 50.9 Polyethene #7 >_ 25 > 54
Claims (38)
1. Use of a polymer composition for melt coating of a rigid pipe, pipe fitting or profile, characterized in that the composition has an environmental stress cracking resistance (ESCR, F20, ASTM 1693) of at least 100 h and comprises a multimodal ethylene polymer, which contains from 80 to 100% by weight of ethylene repeating units and from 0 to 20%
by weight of C3-C10 .alpha.-olefin repeating units, has a density of between 0.915 g/cm3 and 0.955 g/cm3, and is a blend of at least a first ethylene polymer having a first average molecular weight corresponding to a melt flow rate MFR1 2 of from 50 g/10 min.
to 2000 g/10 min. and a first molecular weight distribution and a second ethylene polymer having a second average molecular weight, which is higher than said first average molecular weight, and a second molecular weight distribution, the ratio between the first and second ethylene polymer being from 80:20 to 20:80, said blend having a third average molecular weight corresponding to a melt flow rate MFR3 2 of from 0.1 g/10 min. to 20 g/10 min. and a third molecular weight distribution.
by weight of C3-C10 .alpha.-olefin repeating units, has a density of between 0.915 g/cm3 and 0.955 g/cm3, and is a blend of at least a first ethylene polymer having a first average molecular weight corresponding to a melt flow rate MFR1 2 of from 50 g/10 min.
to 2000 g/10 min. and a first molecular weight distribution and a second ethylene polymer having a second average molecular weight, which is higher than said first average molecular weight, and a second molecular weight distribution, the ratio between the first and second ethylene polymer being from 80:20 to 20:80, said blend having a third average molecular weight corresponding to a melt flow rate MFR3 2 of from 0.1 g/10 min. to 20 g/10 min. and a third molecular weight distribution.
2. The use of claim 1, wherein the polymer composition is for melt coating a rigid iron pipe, iron pipe fitting or iron profile.
3. The use of claim 1, wherein the polymer composition is for melt coating a rigid steel pipe, steel pipe fitting or steel profile.
4. Use of a composition according to any one of claims 1 to 3, characterized in that said blend is the product of a polymerization process comprising at least two steps in which said first ethylene polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a first step and said second ethylene polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a second step, said steps being performed in any order, the ethylene polymer of each step being present in the following step or steps.
5. Use of a composition according to claim 4, characterized in that said blend is the product of said polymerization process, wherein said first step is performed before said second step.
6. Use of a composition according to claim 4 or 5, characterized in that said blend is the product of said polymerization process in which said first step and/or said second step is performed in the presence of a catalyst system comprising a procatalyst based on the tetravalent titanium compound procatalyst TiCl4/MgCl2/optional inert carrier/optional internal electron donor, and a cocatalyst based on a R3Al/optional external electron donor wherein R is a C1-C10 alkyl.
7. Use of a composition according to any one of claims 4 to 6, characterized in that said blend is the product of said polymerization process, in which said catalyst system is added to said first step and the same catalyst system is used at least in said second step.
8. Use of a composition according to any one of claims 4 to 7, characterized in that said blend is the product of said polymerization process, in the first step of which an amount of the chain transfer agent hydrogen, is used, which gives a melt flow rate MFR1 2 for the first ethylene polymer of from 100 g/10 min. to 1000 g/10 min., provided that step 1 is performed first.
9. Use of a composition according to any one of claims 4 to 8, characterized in that said blend is the product of said polymerization process, in which said first step and said second step are performed as a slurry polymerization, gas phase polymerization or a combination thereof.
10. Use of a composition according to any one of claims 4 to 8, characterized in that said blend is the product of said polymerization process, in which said first step is performed as a slurry polymerization, and said second step is performed as a gas phase polymerization.
11. Use of a composition according to any one of claims 4 to 10, characterized in that in said first ethylene polymer, the C3-C10 .alpha.-olefin repeating unit content is from 0 to 10% by weight of said first ethylene polymer.
12. Use of a composition according to any one of claims 4 to 11, characterized in that in said second ethylene polymer, the C3-C10 .alpha.-olefin repeating unit content is from 1 to 25%
by weight and from 2 to 15% by weight, of said second ethylene polymer.
by weight and from 2 to 15% by weight, of said second ethylene polymer.
13. Use of a composition according to any one of claims 4 to 11, characterized in that in said second ethylene polymer, the C3-C10 .alpha.-olefin repeating unit content is from 2 to 15%
by weight, of said second ethylene polymer.
by weight, of said second ethylene polymer.
14. Use of a composition according to any one of claims 4 to 13, characterized in that in said blend, the ratio between said first ethylene polymer and said second ethylene polymer is between 20:80 and 60:40.
15. Use of a composition according to any one of claims 4 to 14, characterized in that the C3-C10 .alpha.-olefin repeating unit content of said blend is from 0.2 to 20% by weight.
16. Use of a composition according to claim 14, characterized in that the C3-C10 .alpha.-olefin content is from 0.5 to 15% by weight, of said blend.
17. Use of a composition according to any one of claims 4 to 16, characterized in that the flow rate ratio FRR3 21/5 of said blend is between 10 and 50, the molecular weight distribution curve showing several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material.
18. Use of a composition according to any one of claims 1 to 3, characterized in that said blend is a mechanical mixture of at least said first ethylene polymer and said second ethylene polymer.
19. Use of a composition according to claim 18, characterized in that said blend is a mechanical melt mixture of said first ethylene polymer and said second ethylene polymer.
20. Use of a composition according to claim 18 or 19, characterized in that the ratio between said first ethylene polymer and said second ethylene polymer is between 20:80 and 60:40.
21. Use of a composition according to any one of claims 18 to 20, characterized in that the melt flow ratio MFR1 2 of said first ethylene polymer is from 100 to 1000 g/10 min.
22. Use of a composition according to any one of claims 18 to 21, characterized in that the melt flow ratio MFR2 21 of said second ethylene polymer is from 0.05 to 50 g/10 min.
23. Use of a composition according to any one of claims 18 to 22, characterized in that said first ethylene polymer has a C3-C10 .alpha.-olefin repeating unit content of from 0 to 10%
by weight of said first ethylene polymer.
by weight of said first ethylene polymer.
24. Use of a composition according to any one of claims 18 to 23, characterized in that said second ethylene polymer has a C3-C10 .alpha.-olefin repeating unit content of from 1 to 25% by weight of said second ethylene polymer.
25. Use of a composition according to any one of claims 18 to 24, characterized in that the melt flow ratio MFR3 2 of said blend is between 0.1 and 50 g/10 min.
26. Use of a composition according to any one of claims 18 to 24, characterized in that the melt flow ratio MFR3 2 of said blend is between 0.1 and 20 g/10 min.
27. Use of a composition according to any one of claims 18 to 25, characterized in that the C3-C10 .alpha.-olefin repeating unit content of said blend is from 0.2 to 20% by weight.
28. Use of a composition according to any one of claims 18 to 27, characterized in that the flow rate ratio FRR3 21/5 of said blend is between 10 and 50, the molecular weight distribution curve showing several peaks or a broad peak lacking small fractions of extremely low and extremely high molecular weight material.
29. Use of a composition according to any one of claims 1 to 28, characterized in that said blend is a blend which has been treated in a tailoring step comprising heating, melt processing and subjecting to controlled free radical reactions to give a molecular weight, which is at least as high as the molecular weight of the untreated blend, and a molecular weight distribution, which is broader than the molecular weight distribution of the untreated blend.
30. Use of a composition according to claim 29, characterized in that said blend is a blend which has been treated in said tailoring step so that during said tailoring step, the relative decrease in the ratio, -( MFR3'5 - MFR3 5):MFR3 5, is from 10 to 80%, wherein MFR3'5 is the melt index of said blend after said tailoring step, wherein MFR3 5 is MFR5 of said blend before said tailoring step.
31. Use of a composition according to claim 30, characterized in that said blend is a blend which has been treated in said tailoring step so that during said tailoring step, the relative broadening of the molecular weight distribution expressed as +(FRR3'21/5 +FRR3 21/5): FRR3 21/5 is from 10 to 80%, wherein FRR3'21/5 is the flow rate ratio of said blend after said tailoring step.
32. Use of a composition according to any one of claims 1 to 31, characterized in that it has an environmental stress cracking resistance (ESCR, F20) of at least 500 h.
33. Use of a composition according to claim 30, characterized in that it has an environmental stress cracking resistance of at least 1000 h.
34. Use of a composition according to any one of claims 1 to 33, characterized in that the composition is used for coating of a substrate comprising a pipe, a primer, covering said pipe, and a coupling agent, covering said primer.
35. The use of claim 34, wherein the pipe is an iron pipe.
36. The use of claim 34, wherein the pipe is a steel pipe.
37. The use of any one of claims 34 to 36, wherein the primer is an epoxy lacquer.
38. The use of any one of claims 34 to 37, wherein the coupling agent is carboxy modified polyethylene.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE9502508A SE504455C2 (en) | 1995-07-10 | 1995-07-10 | Cable sheath composition, its use and methods for its manufacture |
| SE9502508-6 | 1995-07-10 | ||
| FI962366 | 1996-06-07 | ||
| FI962366A FI108452B (en) | 1996-06-07 | 1996-06-07 | Ethylene polymer product with a broad molar mass distribution, production and use thereof |
| PCT/FI1996/000405 WO1997003139A1 (en) | 1995-07-10 | 1996-07-10 | Coating composition |
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|---|---|
| CA2226549A1 CA2226549A1 (en) | 1997-01-30 |
| CA2226549C true CA2226549C (en) | 2008-06-03 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002226549A Expired - Fee Related CA2226549C (en) | 1995-07-10 | 1996-07-10 | Coating composition |
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|---|---|
| US (1) | US6645588B1 (en) |
| EP (1) | EP0837915B1 (en) |
| CN (1) | CN1094963C (en) |
| AT (1) | ATE204600T1 (en) |
| AU (1) | AU6308096A (en) |
| BR (1) | BR9609604A (en) |
| CA (1) | CA2226549C (en) |
| DE (1) | DE69614695T2 (en) |
| ES (1) | ES2161367T3 (en) |
| PL (1) | PL185686B1 (en) |
| PT (1) | PT837915E (en) |
| WO (1) | WO1997003139A1 (en) |
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| DK3009457T3 (en) * | 2014-10-14 | 2017-07-31 | Abu Dhabi Polymers Co Ltd (Borouge) Llc | Geomembrane applications based on polyethylene |
| EP3059485A1 (en) | 2015-02-17 | 2016-08-24 | J. van Beugen Beheer B.V. | Metal pipes with anticorrosive polyolefin covering layer |
| KR102058328B1 (en) | 2016-09-28 | 2019-12-23 | 보레알리스 아게 | Method of manufacturing coated pipe |
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|---|---|---|---|---|
| US3125548A (en) * | 1961-05-19 | 1964-03-17 | Polyethylene blend | |
| US4211595A (en) * | 1978-10-10 | 1980-07-08 | The Kendall Company | Method of coating pipe |
| JPS5610506A (en) * | 1979-07-09 | 1981-02-03 | Mitsui Petrochem Ind Ltd | Production of ethylene polymer composition |
| BR8200530A (en) | 1981-01-30 | 1982-12-07 | Sumitomo Chemical Co | PROCESS TO PRODUCE AN ETHYLENE POLYMER |
| US4438238A (en) | 1981-01-30 | 1984-03-20 | Sumitomo Chemical Company, Limited | Low density copolymer composition of two ethylene-α-olefin copolymers |
| JPS5829841A (en) | 1981-08-14 | 1983-02-22 | Asahi Chem Ind Co Ltd | Improve polyethylene composition |
| US4547551A (en) * | 1982-06-22 | 1985-10-15 | Phillips Petroleum Company | Ethylene polymer blends and process for forming film |
| US5279864A (en) * | 1984-09-13 | 1994-01-18 | Sumitomo Metal Industries, Ltd. | Radiation curable primer coating compositions |
| JPH0725829B2 (en) | 1986-03-07 | 1995-03-22 | 日本石油株式会社 | Method for producing ethylene polymer |
| US4840996A (en) | 1987-11-30 | 1989-06-20 | Quantum Chemical Corporation | Polymeric composition |
| US5047468A (en) | 1988-11-16 | 1991-09-10 | Union Carbide Chemicals And Plastics Technology Corporation | Process for the in situ blending of polymers |
| FI86867C (en) | 1990-12-28 | 1992-10-26 | Neste Oy | FLERSTEGSPROCESS FOR FRAMSTAELLNING AV POLYETEN |
| US5338589A (en) | 1991-06-05 | 1994-08-16 | Hoechst Aktiengesellschaft | Polyethylene molding composition |
| JPH05194796A (en) | 1991-09-18 | 1993-08-03 | Phillips Petroleum Co | Polyethylene blend |
| US5405917A (en) | 1992-07-15 | 1995-04-11 | Phillips Petroleum Company | Selective admixture of additives for modifying a polymer |
| BE1006439A3 (en) | 1992-12-21 | 1994-08-30 | Solvay Societe Annonyme | Method for preparing a composition of polymers of ethylene, polymer composition and use of ethylene. |
| FI98819C (en) | 1993-03-26 | 1997-08-25 | Borealis Polymers Oy | Process for the production of olefin polymers and products made with the process |
| JPH08504883A (en) | 1993-10-15 | 1996-05-28 | フイナ・リサーチ・ソシエテ・アノニム | Method for producing polyethylene showing a broad molecular weight distribution |
| JP3390446B2 (en) | 1993-10-21 | 2003-03-24 | モービル・オイル・コーポレーション | Resin composition containing high molecular weight component and low molecular weight component |
| JP3348514B2 (en) * | 1994-04-27 | 2002-11-20 | 住友化学工業株式会社 | Resin composition for steel coating |
| US5882750A (en) | 1995-07-03 | 1999-03-16 | Mobil Oil Corporation | Single reactor bimodal HMW-HDPE film resin with improved bubble stability |
| FR2826593B1 (en) | 2001-06-27 | 2004-04-16 | Rhodia Chimie Sa | DISPERSION COMPRISING AN EMULSION HAVING AQUEOUS PHASE OF HIGH IONIC FORCE, PREPARATION AND USE |
-
1996
- 1996-07-10 DE DE69614695T patent/DE69614695T2/en not_active Revoked
- 1996-07-10 CA CA002226549A patent/CA2226549C/en not_active Expired - Fee Related
- 1996-07-10 PT PT96922070T patent/PT837915E/en unknown
- 1996-07-10 AT AT96922070T patent/ATE204600T1/en not_active IP Right Cessation
- 1996-07-10 AU AU63080/96A patent/AU6308096A/en not_active Abandoned
- 1996-07-10 BR BR9609604A patent/BR9609604A/en not_active IP Right Cessation
- 1996-07-10 ES ES96922070T patent/ES2161367T3/en not_active Expired - Lifetime
- 1996-07-10 CN CN96196245A patent/CN1094963C/en not_active Expired - Fee Related
- 1996-07-10 WO PCT/FI1996/000405 patent/WO1997003139A1/en active IP Right Grant
- 1996-07-10 EP EP96922070A patent/EP0837915B1/en not_active Revoked
- 1996-07-10 PL PL96325016A patent/PL185686B1/en not_active IP Right Cessation
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2000
- 2000-07-24 US US09/624,279 patent/US6645588B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| AU6308096A (en) | 1997-02-10 |
| US6645588B1 (en) | 2003-11-11 |
| CA2226549A1 (en) | 1997-01-30 |
| ATE204600T1 (en) | 2001-09-15 |
| EP0837915A1 (en) | 1998-04-29 |
| WO1997003139A1 (en) | 1997-01-30 |
| CN1195363A (en) | 1998-10-07 |
| BR9609604A (en) | 1999-05-25 |
| ES2161367T3 (en) | 2001-12-01 |
| DE69614695D1 (en) | 2001-09-27 |
| CN1094963C (en) | 2002-11-27 |
| PL185686B1 (en) | 2003-07-31 |
| DE69614695T2 (en) | 2002-06-20 |
| EP0837915B1 (en) | 2001-08-22 |
| PL325016A1 (en) | 1998-07-06 |
| PT837915E (en) | 2001-12-28 |
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