Patent ID: 6326068
Filing Date: 2001-12-04
Classification: B32B,Y10S,Y10T

Abstract:
A multilayer film for forming hermetic seals on packages comprising:(a) layer A of polypropylene copolymer with melt flow rate greater than one or linear high density polyethylene with melt index greater than one;(b) layer B of polypropylene;(c) layer C of deformable random copolymer which is sufficiently deformable under heat seal conditions, said deformable random copolymer being selected from ethylene-propylene copolymer, ethylene-propylene-butene-1 terpolymer, propylene-butene copolymer, and mixtures thereof; and(d) layer D of heat sealable polymer with a melting point equal to or lower than layer C polymer, said heat sealable polymer being selected from ethylene-propylene copolymer, ethylene-propylene-butene-1 terpolymer, propylene-butene copolymer, and mixtures thereofwherein layer C is thicker than layer D; wherein layer D is loaded with an antiblocking agent comprising non-distortable organic polymer particles having an average particle size greater than 6 microns; and wherein the film layer order is A/B/C/D.