Patent ID: 6040028
Filing Date: 2000-03-21
Classification: C08G,C08L,C09J,Y02P,Y10T

Abstract:
In a process for coating a substrate comprising applying a composition to a substrate, and allowing the composition to cure, the improvement wherein said composition comprises a highly elastic polyurethane contact adhesive which is the reaction product of a mixture consisting ofa) a polyisocyanate or polyisocyanate adduct having a functionality of less than about 4,andb) a polyol component consisting of:1) about 90 to 100% by weight, based on 100% by weight of component b), of at least one polyether having a molecular weight of from about 1,800 to 12,000 and an average functionality of from about 1.5 to about 4,and2) up to about 10% by weight, based on 100% by weight of component b), of at least one chain extender containing hydroxyl groups and having a molecular weight of from about 60 to 400 and an average functionality of from about 1.5 to about 3,wherein at least one of components a) and b) have an average functionality greater than 2.2 and the functionalities and quantities of components a) and b) are selected such that the molecular weight between crosslinks of the resultant polyurethane is from about 7,000 to about 16,000, the equivalent ratio of isocyanate groups to isocyanate-reactive groups present in the resultant polyurethane is from about 80:1000 to about 120:100 and the urethane group content of the resultant polyurethane is from about 1 to about 8%.