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CN-115380078-B - Polymer composition for waterproof breathable film

CN115380078BCN 115380078 BCN115380078 BCN 115380078BCN-115380078-B

Abstract

The present invention relates to a composition consisting of 75 to 98% by weight, relative to the weight of the composition, of at least one hydrophilic elastomeric Thermoplastic Polymer (TPE) A chosen from (a 1) copolymers containing polyester blocks and polyether blocks, (a 2) copolymers containing polyurethane blocks and polyether blocks or polyester blocks and/or mixtures thereof, 2 to 15% by weight, relative to the weight of the composition, of at least one copolymer B comprising units derived from ethylene, alkyl (meth) acrylates and comonomers comprising at least one acid, anhydride or epoxide function, and 0 to 10% by weight, relative to the weight of the composition, of at least one additive. The invention further relates to a process for manufacturing the membrane and to said membrane.

Inventors

  • C. Cockwatt

Assignees

  • 阿科玛法国公司
  • 阿科玛法国公司

Dates

Publication Date
20260421
Application Date
20210407
Priority Date
20200407

Claims (20)

  1. 1. A composition consisting of: -75 to 98% by weight of at least one hydrophilic thermoplastic elastomer (TPE) polymer a selected from (a 2) copolymers containing polyurethane blocks and polyether or polyester blocks and/or (a 1) copolymers containing polyester blocks and polyether blocks and (a 2) a mixture of copolymers containing polyurethane blocks and polyether or polyester blocks, relative to the weight of the composition; -2 to 15% by weight of at least one copolymer B comprising units derived from ethylene, alkyl (meth) acrylate and a comonomer comprising at least one acid, anhydride or epoxide function, wherein the units derived from ethylene have a molar content of 50 to 94.9% in copolymer B, the units derived from alkyl (meth) acrylate have a molar content of 20 to 30% in copolymer B, and the units derived from the comonomer comprising at least one acid, anhydride or epoxide function are present in copolymer B in a molar content of 0.1 to 15%, relative to the weight of the composition, and -0 To 10% by weight of at least one additive, relative to the weight of the composition.
  2. 2. The composition as claimed in claim 1, wherein the alkyl (meth) acrylate comprises an alkyl group comprising 1 to 24 carbon atoms.
  3. 3. The composition as claimed in claim 2, wherein the alkyl (meth) acrylate comprises an alkyl group comprising 1 to 5 carbon atoms.
  4. 4. A composition according to any one of claims 1 to 3, wherein the alkyl (meth) acrylate is selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate, and combinations thereof.
  5. 5. A composition according to one of claims 1 to 3, wherein the molar content of units derived from alkyl (meth) acrylate in copolymer B is from 5% to 35%.
  6. 6. A composition according to one of claims 1 to 3, wherein the molar content of comonomer comprising at least one acid, anhydride or epoxide function in copolymer B is from 0.1% to 15%.
  7. 7. A composition according to one of claims 1 to 3, wherein the comonomer comprising at least one acid, anhydride or epoxide functional group is selected from unsaturated carboxylic anhydrides.
  8. 8. The composition of claim 7 wherein the comonomer comprising at least one acid, anhydride or epoxide functional group is selected from maleic anhydride.
  9. 9. A composition according to one of claims 1 to 3, wherein the comonomer comprising at least one acid, anhydride or epoxide functional group has an unsaturated epoxide functional group.
  10. 10. The composition of claim 9 wherein the comonomer comprising at least one acid, anhydride or epoxide functional group is glycidyl methacrylate.
  11. 11. A composition according to one of claims 1 to 3, wherein copolymer B is free of units derived from vinyl acetate.
  12. 12. A composition according to one of claims 1 to 3, wherein the additive is selected from the group consisting of inert dyes, fillers, surfactants, cross-linking agents, nucleating agents, reactive compounds, mineral or organic flame retardants, ultraviolet (UV) or Infrared (IR) light absorbers, UV or IR fluorescent agents, and combinations thereof.
  13. 13. The composition of claim 12 wherein the inert dye is titanium dioxide.
  14. 14. Process for manufacturing a film comprising extruding a composition according to one of claims 1 to 13.
  15. 15. The process as set forth in claim 14 wherein the membrane is a waterproof breathable membrane.
  16. 16. A process as claimed in claim 14, wherein the extrusion is carried out at a temperature of 100 to 300 ℃.
  17. 17. The process of any one of claims 14 to 16, wherein extrusion is extrusion coating or extrusion casting.
  18. 18. Film obtained by the process according to one of claims 14 to 17.
  19. 19. A film as claimed in claim 18, having a thickness of 2 to 100 μm.
  20. 20. A film as claimed in claim 19 having a thickness of 10 to 50 μm.

Description

Polymer composition for waterproof breathable film Technical Field The present invention relates to a polymer composition and a waterproof breathable film obtained using said composition. Background Films that are impermeable to liquid water and permeable to water vapor are used in various fields such as textiles, construction, agriculture, packaging, and the like. For example, these films may be used as a package to wrap an article or as a coating to adhere to the surface of an article. In general, breathable films must meet certain requirements, such as uniform appearance, resistance to wind, high permeability to water vapor, certain elasticity, and the ability to adhere to different substrates. Furthermore, these films must be easy to process during production (especially by extrusion) without causing deformations in the film. Poor processability is reflected by imperfections in the film, such as holes or irregular edges. The use of components comprising polyamide blocks and polyether blocks to form such films is a known practice. However, despite the high permeability to water vapor, the formed film is rarely stretchable, which causes problems when it is manufactured by extrusion (particularly by extrusion coating). Furthermore, the use of terpolymer compositions, in particular terpolymers derived from ethylenic, acrylic and butene monomers, makes it possible to obtain films which can be easily processed by extrusion. However, these films have very low breathability. US 2004/0 029 467 relates to a breathable film comprising at least one polymer (a) selected from ethylene/(meth) acrylic acid alkyl ester copolymer (a 1), optionally neutralized ethylene/(meth) acrylic acid copolymer (a 2), ethylene/vinyl monomer copolymer (a 3), mixture (a 1)/(a 2), mixture (a 1)/(a 3), mixture (a 2)/(a 3) and mixture (a 1)/(a 2)/(a 3), and/or comprising at least one functionalized polyethylene (b), and at least one copolymer (c) containing copolyamide blocks or polyester blocks and polyether blocks. US 5 614 588 relates to a polymer blend comprising a polyether block amide consisting of 30 to 60 wt.% of polyamide-12, polyamide-11 and/or polyamide-12, 12 blocks and 70 to 40 wt.% of polyethylene glycol blocks, a polyether block amide consisting of 65 to 85 wt.% of polyamide-12, polyamide-11 and/or polyamide-12, 12 blocks and 35 to 15 wt.% of polyethylene glycol blocks, and a poly (ethylene-co-vinyl acetate-g-maleic anhydride) polymer consisting of 75 to 95 wt.% of ethylene, 5 to 25 wt.% of vinyl acetate and 0.1 to 2 wt.% of maleic anhydride. The compositions of said document are used to manufacture membranes permeable to water vapor. US 5 506 024 relates to a membrane permeable to water vapor made from a thermoplastic elastomer based on polyether ester amide (and preferably on polyether block amide). US 5 800 928 relates to a film permeable to water vapor comprising at least one thermoplastic elastomer comprising polyether blocks and at least one copolymer comprising ethylene and at least one alkyl (meth) acrylate. There is a need to provide a composition that allows the manufacture of films that have good permeability to water vapor and good processability during the manufacture of the film. Disclosure of Invention The invention first relates to a composition consisting of: From 75 to 98% by weight of at least one hydrophilic thermoplastic elastomer (referred to herein as TPE) polymer a selected from (a 1) Copolymers (COPE) containing polyester blocks and polyether blocks, (a 2) copolymers containing polyurethane blocks and polyether or polyester blocks (TPU) and/or mixtures thereof, relative to the weight of the composition; from 2 to 15% by weight of at least one copolymer B comprising units derived from ethylene, alkyl (meth) acrylate and a comonomer comprising at least one acid, anhydride or epoxide function, relative to the weight of the composition, and -0 To 10% by weight of at least one additive, relative to the weight of the composition. For the purposes of the present invention, copolymers containing polyester blocks and polyether blocks (hereinafter referred to as COPE or copolyetheresters) are copolymers containing polyester blocks and polyether blocks. They consist of flexible polyether blocks derived from polyether diols and rigid polyester blocks derived from the reaction of at least one dicarboxylic acid with at least one short chain extension diol unit. The polyester blocks and polyether blocks are linked by ester linkages resulting from the reaction of the acid functionality of the dicarboxylic acid with the OH functionality of the polyether diol. The linkage of the polyether and the diacid forms a flexible block, while the linkage of the ethylene glycol or the butanediol with the diacid forms a rigid block of the copolyetherester. The short chain extended diol may be selected from neopentyl glycol, cyclohexanedimethanol and aliphatic diols of the formula HO (CH 2)n OH, where n is an integer from 2 to 10.