Patent ID: 6063891
Filing Date: 2000-05-16
Classification: C08G

Abstract:
A freeze-stable urethane prepolymer of an allophanate-modified, partially modified toluene diisocyanate or polyisocyanate having an NCO group content of from about 14 to 40%, and comprising the reaction product of:(I) a freeze-stable allophanate-modified, partially trimerized toluene diisocyanate or polyisocyanate having an NCO group content of from 15 to 42% and comprising the reaction product of:A) toluene diisocyanateandB) an organic compound containing at least one hydroxyl group,in the presence of a catalytic amount ofC) at least one allophanate-trimer catalyst or an allophanate-trimer catalysts system;wherein component B) is present in a quantity such that there are from about 0.015 to about 0.2 equivalent hydroxyl groups per equivalent of isocyanate of the TDI present, at least about 50% of the urethane groups are converted to allophanate groups by C) said catalyst or catalyst system, and a catalyst stopper is added once the desired NCO group content is attained;and(III) an isocyanate-reactive component containing from about 1.5 to about 4 hydroxyl groups and having a molecular weight of from about 76 to about 10,000.