Patent ID: 8202590

Claim:
A multilayer oriented heat shrinkable film consisting essentially of: A) a structural layer comprising a polymer selected from the group consisting of copolymers of ethylene and a C 3 to C 8 α,β-ethylenically unsaturated carboxylic acid, ionomers of said copolymers, polyesters, and blends thereof; B) a heat sealing layer consisting essentially of a polymer selected from the group consisting of ethylene vinyl acetate copolymers, ethylene alkyl acrylate copolymers, ethylene alkyl methacrylate copolymers, polyethylene, and blends thereof; and C) a gas barrier layer consisting essentially of at least one ethylene vinyl alcohol copolymer, said ethylene vinyl alcohol copolymer having from about 2 to about 8 mol % 1,2 glycol structural units present in the polymer chain and said gas barrier layer being positioned between said structural layer and said heat sealing layer; and D) an adhesive layer wherein said adhesive layer comprises: 1) at least one functionalized polymer component selected from the group consisting of a) anhydride-modified polymers, b) copolymers comprising copolymerized units of ethylene and a comonomer selected from the group consisting of C 4 -C 8 unsaturated anhydrides, monoesters of C 4 -C 8 unsaturated acids having at least two carboxylic acid groups, diesters of C 4 -C 8 unsaturated acids having at least two carboxylic acid groups and c) mixtures thereof, 2) an ethylene copolymer, chemically distinct from said functionalized polymer component, comprising copolymerized units of ethylene and a comonomer selected from the group consisting of alpha-olefins, vinyl acetate, alkyl acrylates, alkyl methacrylates and mixtures thereof, said alkyl groups having from 1 to 10 carbon atoms; and optionally 3) a tackifier resin characterized in that i) said multilayer film is capable of shrinking to a size that is at least 25% less than its original size on initial exposure of said film to a temperature of 85° C. for at least one minute and further characterized in that after exposure to a temperature of 85° C. for at least one minute, said film will maintain a percent shrinkage of at least 30% less than its original size in both the machine and transverse directions for a period of at least ten weeks and ii) the secant modulus of said multilayer film in either of the machine or transverse directions, is in the range of 206-268 MPa when measured in accordance with ASTM D882.