Isocyanate group-terminated urethane prepolymer, process for producing the same, and adhesive comprising the urethane prepolymer

摘要

It is an object of the present invention to provide an isocyanate group-terminated urethane prepolymer which has a low viscosity at melting and a process for producing the same, and an adhesive which comprises the urethane prepolymer. The invention relates to a process for producing an isocyanate group-terminated urethane prepolymer which comprises reacting polyols with a polyisocyanate compound, wherein the polyols comprise 10 to 50% by mass of a polyester polyol and 90 to 50% by mass of a polycarbonate polyol and wherein a sebacic acid-derived polyester polyol which is a polycondensate of sebacic acid with a diol compound accounts for 50 to 100% by mass of the polyester polyol and wherein the polyisocyanate compound and the polyols are reacted in such amounts that the ratio (by mol) of the isocyanate group/hydroxyl group is 1.2 to 3.2.