Patent ID: 8420176

Claim:
A method for preparing a selectively permeable multilayer structure or article comprising: (1) preparing a first composition comprising (i) one or more ethylene acid copolymers; and (ii) one or more organic acids; wherein at least 50% of the combined acidic groups in the acid copolymer and the organic acid are nominally neutralized to salts with metal ions and at least 50% of the metal ions are alkali metal ions; (2) melt blending the first composition with one or more ethylene-containing polymers selected from the group consisting of polyethylene (PE) homopolymers, copolymers of ethylene and an α-olefin, copolymers of ethylene and a diolefin, and ethylene copolymers obtained from copolymerization of ethylene with at least one polar monomer selected from the group consisting of vinyl acetate, acrylic ester, methacrylic ester and carbon monoxide, wherein ethylene-containing polymer does not comprise a dicarboxylic acid derivative, to provide a second composition; (3) melt blending the second composition with a polymer comprising 0.1 to 15 weight % of a dicarboxylic acid derivative selected from the group consisting of maleic anhydride, citraconic anhydride, itaconic anhydride, tetrahydrophthalic anhydride, monoalkyl esters of maleic acid, fumeric acid, citraconic acid, itaconic acid or tetrahydrophthalic acid, and combinations thereof, to provide a third composition in a molten condition; (4) contacting a substrate with the molten third composition to adhere, embed, or impregnate the melted composition to the substrate or adhere, embed, or impregnate the substrate to the molten third composition to provide a coated substrate with the third composition in a molten condition; (5) cooling the coated substrate to allow the molten third composition to cool and solidify.