Heat seal composition comprising a blend of metal neutralized polymers

Claim 1

A substantially homogeneous blend of polymeric materials comprising: (a) 20 to 80 percent, by weight, of a terpolymer having, as monomeric components, (i) 65 to 95 percent, by weight, ethylene, (ii) 4 to 30 percent, by weight, vinyl alkanoate or an ester selected from the group consisting of alkyl acrylate, and alkyl methacrylate wherein the alkanoic acid moiety of the alkanoate and the alkyl group have one to four carbon atoms, and (iii) 0.5 to 20 percent, by weight, ethylenically unsaturated monocarboxylic acid selected from the group consisting of acrylic acid and methacrylic acid; and (b) 20 to 80 percent, by weight, of an ionomer having, as monomeric components, (i) 75 to 99 percent, by weight, ethylene, (ii) 1 to 25 percent, by weight, ethylenically unsaturated monocarboxylic acid selected from the group consisting of acrylic acid and methacrylic acid wherein the sum of the weight percentages of comonomers (ii) and (iii) in the terpolymer is at least eight percentage points higher than the weight percentage of comonomer (ii) in the ionomer and wherein 5 to 40 percent of the carboxylic acid in the blend is neutralized by zinc ions.