Patent ID: 6632913
Filing Date: 2003-10-14
Classification: C08G

Abstract:
A method for producing a liquid urethane prepolymer which comprises:reacting a lactone-modified diol (3) with a polyisocyanate (4) to form a urethane prepolymer precusor having an isocyanate group (5), wherein said lactone-modified diol (3) is obtained by ring-opening addition polymerization of a lactone monomer (2) with a diol (1) selected from the group consisting of a polyalkylene ether diol and a polyester diol obtained by reaction of a dihydric alcohol with a dibasic carboxylic acid; and then reacting said urethane prepolymer precursor (5) with a blocking agent (6) to obtain the liquid urethane prepolymer having the isocyanate group blocked by the blocking agent.