The Kazuhei equal molecular weight 1000 - 6000 polyoxyalkylene mono all which is (B1), the Kazuhei equal molecular weight 4500 - 25000

摘要

PPROBLEM TO BE SOLVED: To provide a method for manufacturing a transparent polyurethane resin that has low hardness as well as flexibility and resilience, and that is suitable for optical material applications. PSOLUTION: This transparent polyurethane resin is manufactured by reacting hydroxy group-containing compounds comprising, at a specified ratio, a polyoxyalkylene monool (B1) having a number average molecular weight of 1,000-6,000, a polyoxyalkylene polyol (C1) having a number average molecular weight of 4,500-25,000 and having two functional groups, and a polyoxyalkylene polyol (D) having a number average molecular weight of 1,000-25,000 and having three functional groups, with a polyisocyanate compound (A). Neither plasticizer nor solvent is added. Furthermore, the transparent polyurethane resin preferably has a hardness of less than 5 when measured using a type-A hardness testing machine according to JIS K6301, and a hardness of not more than 30 when measured using a type-C hardness testing machine according to JIS K6301. PCOPYRIGHT: (C)2006,JPO&NCIPI