Patent ID: 6087020
Filing Date: 2000-07-11
Classification: B29C,B32B,Y10T

Abstract:
A film having low permeability to hydrocarbons consisting essentially of a central layer (i) formed of a polyamide/polyolefin alloy having a polyamide matrix, wherein the alloy further comprises a compatibility-ensuring agent and of two outer layers (ii) and (iii) each formed of polyolefin, in which said polyamide/polyolefin alloy is selected from the following alloys:an alloy comprising, in % by weight, (a) 55 to 70% PA-6, (b) 5 to 15% of an ethylene/propylene copolymer, wherein the molar ratio of ethylene to propylene in the ethylene/propylene copolymer is<1, grafted with maleic anhydride then condensed with mono-amino oligomers of caprolactam; (c) made up to 100% with polypropylene;an alloy comprising, in % by weight, (a) 55 to 70% PA-6, (b) 5 to 15% of at least one ethylene copolymer with (i) an alkyl (meth)acrylate or an unsaturated carboxylic acid vinyl ester and (ii) an unsaturated carboxylic acid anhydride or an unsaturated epoxy, monomer (ii) being grafted or copolymerized; (c) made up to 100% with polyethylene; andan alloy comprising, in % by weight, (a) 55 to 70% PA-6; (b) 5 to 15% polyethylene or copolymers of ethylene and an alpha-olefin grafted with maleic anhydride or glycidyl methacrylate; (c) made up to 100% with polyethylene.