PRODUCTION OF POLYURETHANE ELASTOMER OF LOW DYNAMIC HEAT BUILD-UP

摘要

PURPOSE:To produce the titled elastomer having low heat build-up and excellent solvent resistance, by conducting the reaction of a specified urethane prepolymer with a specified polyol one or both of which contain an epsilon-caprolactone chain. CONSTITUTION:An isocyanato group-terminated urethane prepolymer obtained by reacting W1pts.wt. polyol containing 0-95wt% epsilon-caprolactone chain and having a molecular weight MW1=500 and an (average)hydroxyl group functionality F1=2 (polyol A) with W2pts.wt. organic polyisocyanate having an (average) isocyanate group functionality F2=2 is reacted with W3pts.wt. polyol containing 0-95wt% epsilon-caprolactone chain and having a molecular weight MW2=5,000 and an (average) hydroxyl group functionality F3=2.2 (polyol B) to obtain the titled elastomer which is a polyurethane elastomer having a crosslinking density (CD) =0.085 (determined from the equation, wherein MW2 is the MW of an organic polyisocyanate) and in which one or both of polyols A and B contain an epsilon-caprolactone chain.