Polyurethane urea heat seal adhesive for the preparation of heat sealable padding material

Abstract

The invention disclosed herein relates to a method for bonding the opposing surfaces of textile materials to each other with a heat-seal adhesive. The heat-seal adhesive is a polyurethane urea heat-seal adhesive prepared by first preparing a chain-extended polyurethane from at least one diisocyanate, at least one polydiol, and chain-extenders. The chain-extenders may comprise a mixture of low molecular weight diols comprised of at least one low molecular weight diol having a molecular weight below about 500 and having side chains or ether groups, and at least one unbranched low molecular weight diol having a molecular weight below about 500. The chain-extended polyurethane has a free-isocyanate group content which comprises from about 10 to about 40 mole percent of the isocyanate content of the starting mixture. An emulsifier is added to the chain-extended polyurethane, and the polyurethane and emulsifier mixture is emulsified with water. Diamines or diamine mixtures may be added to the emulsion.

Dependencies are inferred from the claim text.