Patent ID: 7635509

Claim:
A vacuum sealed package comprising multiple layers of film, wherein the package is produced by a process comprising the steps of: (A) providing a multilayer package structure comprising (i) at least one oxygen-permeable film web layer, wherein said oxygen-permeable layer comprises a blend of: (a) one or more aliphatic organic acids or salts thereof having fewer than 36 carbon atoms; (b) at least one E/X/Y copolymer or ionomer of said E/X/Y copolymer wherein E is derived from ethylene, X is derived from at least one C 3 to C 8 α,β-ethylenically unsaturated carboxylic acid, and Y is derived from a comonomer selected from the group consisting of alkyl acrylates and alkyl methacrylates, wherein the alkyl groups of said alkyl acrylates and said alkyl methacrylates have from 1 to 8 carbon atoms, wherein X is from about 3 to about 30 weight % of said E/X/Y copolymer, and Y is from 0 to about 35 weight % of said E/X/Y copolymer, and wherein greater than 70% of the total acid moieties of (a) plus (b) are neutralized by adding the stoichiometric amount of a cation source calculated to neutralize the target amount of acid moieties in the acid copolymer and organic acid or acids in the blend, wherein the cation source is selected from the group consisting of alkaline metals, alkaline earth metals, and transition metals; and (c) at least one additional ethylene-containing polymer selected from the group consisting of ethylene homopolymers, ethylene copolymers and mixtures thereof; with the proviso that said at least one additional ethylene-containing copolymer is other than an ethylene acid copolymer or an ionomer of an ethylene acid copolymer; and (ii) at least one polymeric film web layer consisting essentially of at least one ethylene-containing polymer or a mixture of ethylene-containing polymers; (B) applying a vacuum to said multilayer package structure; and (C) heat sealing the perimeters of said film web layers together.