ISOCYANATO-TERMINATED PREPOLYMER, ITS PRODUCTION AND CURABLE POLYURETHANE COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide an isocyanato-terminated prepolymer excellent in storage stability and to provide a curable polyurethane excellent in mechanical properties such as strengths, elongation and hardness. SOLUTION: A polyoxyalkylenepolyol having a hydroxyl value (OHV) and a total degree of unsaturation (C=C) satisfying the following requirements and having CPR which represents the amount of a basic substance in the polyol of 5 or below is reacted with a polyisocyanate compound to produce an isocyanato-terminated prepolymer. A curable polyurethane is obtained by using this compound. The region including an OHV of 10-35mgKOH/g and a C=C of 0.03-0.1meq/g, excluding the ranges defined by formulas a and b: a: C=C >4.59×OHV<-1.34> +0.002 (OHV is 17.6-35.0mgKOH/g), and b: C=C <1.59×OHV<-1.20> (OHV is in the range of 10.0-21.7mgKOH/g).