Patent ID: 6060560
Filing Date: 2000-05-09
Classification: C08G,C09D,Y10T

Abstract:
A process for producing a polyurethane resin from a hydrogenated polydiene diol having a hydroxyl equivalent weight of 750 to 10000, a reinforcing agent having a functional group equivalent weight of 30 to 200, and a polyisocyanate curing agent which comprises:(a) reacting at least one of the polydiene diol (or polyol) or the reinforcing agent with the polyisocyanate at an NCO/OH molar ratio between 0.4 and 0.7 to form a stable reaction product, wherein the polyisocyanate has more than two isocyanate groups when reacted with the polydiene diol, or two or more isocyanate groups when reacted with the polydiene polyol,(b) adding to the product of (a) an additional sufficient amount of the polyisocyanate and, as needed, one or both of the polydiene diol (or polyol) or the reinforcing agent to bring the NCO/OH ratio up to 0.9 to 1.1 and to achieve a polydiene diol or polyol content of 35 to 80% w (on solids basis) and a reinforcing agent content of 2 to 17% w (on solids basis), and(c) reacting the mixture of (b) to form a crosslinked polyurethane product.