Patent ID: 8399098

Claim:
A laminate comprising at least one interlayer sheet that is laminated to one or more rigid sheets, to one or more other interlayer sheets, or to one or more film layers, said at least one interlayer sheet comprising a sodium/zinc mixed ionomer composition, said sodium/zinc mixed ionomer composition comprising a sodium/zinc mixed ionomer that is the neutralization product of a precursor acid copolymer; wherein (a)(i) the precursor acid copolymer comprises copolymerized units of ethylene and about 20 to about 30 wt %, based on the total weight of the precursor acid copolymer, of copolymerized units of an α,β-ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic acid and methacrylic acid; wherein (ii) the precursor acid copolymer has a melt flow rate of about 70 to about 4000 g/10 min, as determined in accordance with ASTM D1238 at 190° C. and 2.16 kg; wherein (iii) the precursor acid copolymer, being neutralized to a level of about 40% to about 90% based on the total number of the carboxylic acid groups present in the precursor acid copolymer, produces a sodium ionomer, said sodium ionomer comprising carboxylate groups and counterions, and said counterions consisting essentially of sodium cations,and wherein (iv) the sodium ionomer has a melt flow rate of about 0.7 to about 25 g/10 min and a freeze enthalpy that is not detectable or that is less than about 3.0 j/g, as determined by differential scanning calorimetry in accordance with ASTM D3418; and (b) said sodium/zinc mixed ionomer comprises carboxylate groups and a combination of counterions; said combination of counterions consisting essentially of about 5 to about 95 equivalent % of sodium cations, and about 95 to 5 equivalent % of zinc cations, based on the total number of equivalents of carboxylate groups in the sodium/zinc mixed ionomer.