Breathable film

• US 20040029467A1
• Filed: 07/07/2003
• Published: 02/12/2004
• Est. Priority Date: 08/04/2000
• Status: Active Grant

• Current Assignee: SK Global Chemical Co., Ltd. (SK Innovation Company Limited)
• Original Assignee: Arkema
• Inventors: Lacroix, Christophe
• Granted Patent: US 8,029,892 B2
• Time in Patent Office: Days
• US Class Current: 442/76
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: C08J 2323/08 Copolymers of ethene C08J2323/16 takes precedence
• CPC Class Codes: C08J 2377/12 Polyester-amides
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08L 23/00 Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 23/08 Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/0869 Acids or derivatives thereof
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 51/06 grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 71/00 Compositions of polyethers obtained by reactions forming an ether link in the main chain of polyacetals C08L59/00; of epoxy resins C08L63/00; of polythioether-ethers C08L81/02; of polyether-sulfones C08L81/06; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 77/00 Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 77/06 Polyamides derived from polyamines and polycarboxylic acids C08L77/10 takes precedence
• CPC Class Codes: C08L 77/12 Polyester-amides
• CPC Class Codes: Y10S 525/926 Polyamide containing a plurality of oxyalkylene groups
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/31725 Of polyamide
• CPC Class Codes: Y10T 442/2139 Coating or impregnation specified as porous or permeable to a specific substance [e.g., water vapor, air, etc.]
• CPC Class Codes: Y10T 442/674 Nonwoven fabric with a preformed polymeric film or sheet
• CPC Class Codes: Y10T 442/676 Vinyl polymer or copolymer sheet or film [e.g., polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, etc.]
• CPC Class Codes: Y10T 442/678 : Olefin polymer or copolymer sheet or film [e.g., polypropylene, polyethylene, ethylene-butylene copolymer, etc.]

Abstract

A breathable film includes at least one polymer (a) taken from the group comprising an ethylene/alkyl (meth)acrylate copolymer (a1), an optionally neutralized ethylene/ (meth)acrylic acid copolymer (a2), an ethylene/vinyl monomer copolymer (a3), the (a1)/(a2) blend, the (a1)/(a3) blend, the (a2)/(a3) blend and the (a1)/(a2)/(a3) blend, and/or includes at least one functionalized polyethylene (b); and at least one copolymer (c) having copolyamide blocks or polyester blocks and polyether blocks.

Claims

1. A breathable film comprising a blend:

of at least one polymer (a) taken from the group comprising an ethylene/alkyl (meth)acrylate copolymer (a1), an optionally neutralized ethylene/ (meth)acrylic acid copolymer (a2), an ethylene/vinyl monomer copolymer (a3), the (a1)/(a2) blend, the (a1)/(a3) blend, the (a2)/(a3) blend and the (a1)/(a2)/(a3) blend; and

/or

of at least one functionalized polyethylene (b); and

of at least one copolymer (c) having copolyamide blocks or polyester blocks and polyether blocks.

2. The breathable film as claimed in claim 1, in which the copolymer (c) has a melting point of between 80 and 150°

C., preferably between 90 and 135°

C.

3. The breathable film as claimed in either of claims 1 and 2, in which the copolymer (c) having copolyamide blocks and polyether blocks is a polyetheresteramide.

4. The breathable film as claimed in one of claims 1 to 3, in which the copolyamide blocks result from the condensation of at least one alpha,omega-aminocarboxylic acid or a lactam, at least one diamine and at least one dicarboxylic acid.

5. The breathable film as claimed in one of claims 1 to 4, in which the copolyamide blocks derive from 6, 11, 12, 6,6, 6,10 or 6,12 blocks.

6. The breathable film as claimed in one of claims 1 to 5, in which the polyether blocks are PEG blocks.

7. The breathable film as claimed in one of claims 1 to 6, in which the alkyl (meth)acrylate (a1) is chosen from n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, n-octyl acrylate, methyl methacrylate and ethyl methacrylate.

8. The breathable film as claimed in one of claims 1 to 7, in which the functionalized polyethylene (b) is a functionalized ethylene/alkyl (meth)acrylate copolymer.

9. The breathable film as claimed in one of claims 1 to 8, in which the functionalized polyethylene (b) is a polyethylene or an ethylene/alkyl (meth)acrylate copolymer, functionalized by a monomer chosen from (i) an unsaturated carboxylic acid, (ii) an unsaturated carboxylic acid anhydride and (iii) an unsaturated epoxide, by grafting or copolymerization.

10. The breathable film as claimed in one of claims 1 to 8, in which the functionalized polyethylene (b) is grafted or copolymerized with a glycidyl methacrylate.

11. The breathable film as claimed in one of claims 1 to 10, in which the polymer (b) represents from 1 to 40%, preferably from 2 to 20%, more preferably from 3 to 15% by weight of the final composition.

12. The breathable film as claimed in one of claims 1 to 11, in which the polymer (c) represents from 20 to 95%, preferably from 25 to 80%, more preferably from 30 to 70% by weight of the final composition.

13. The breathable film as claimed in one of claims 1 to 12, in which the polymer (a) represents from 10 to 90%, preferably from 40 to 80% by weight of the final composition.

14. The breathable film as claimed in one of claims 1 to 13, in which the sum of the polymers (a) and (b) preferably represents more than 50%, more preferably more than 55% by weight of the final composition.

15. The breathable film as claimed in one of claims 1 to 13, in which the sum of the polymers (a) and (b) preferably represents less than 50%, more preferably less than 45% by weight of the final composition.

16. The breathable film as claim in one of claims 1 to 15, comprising:

from 40 to 80%, preferably 45 to 75%, of the polymer (a);

from 2 to 20%, preferably 3 to 15% of the copolymer (b);

the sum of the constituents (a) and (b) being equal to at least 50%, preferably at least 55%; and

from 18 to 50%, preferably 22 to 45%, of at least one copolymer (c) having copolyamide blocks or polyester blocks and polyether blocks.

17. The breathable film as claimed in one of claims 1 to 16, having a thickness of between 10 and 220 μ

m.

18. A process for manufacturing a film as claimed in one of claims 1 to 17, which comprises the extrusion of said film.

19. A breathable material comprising the film as claimed in one of claims 1 to 17, combined with a nonwoven or with a woven.

20. The breathable material as claimed in claim 19, characterized in that the copolymer blend making up the film as claimed in one of claims 1 to 17 is extruded and laminated to a woven or nonwoven fabric substrate.

21. The process for manufacturing a breathable material as claimed in claim 20, comprising the extrusion and the lamination of the copolymer blend making up the film as claimed in one of claims 1 to 17 to a woven or nonwoven fabric substrate.