To obtain a highly rigid polyurethane resin excellent in molding processability, low-temperature impact resistance, high-temperature dimensional stability, water resistance, etc., and useful for formworks, by using a specific chain extender and a specific isocyanate compound.
This polyurethane resin is obtained by using (A) an isocyanate component consisting essentially of (A1) a polyisocyanate having asymmetric structure such as 2,4'-diphenylmethane diisocyanate or 2,4-tolylene diisocyanate, or (A2) an isocyanate group-terminated polyurethane prepolymer prepared by reaction of A1 with a polyol compound and (B) an active hydrogen component containing (B1) a chain extender ≥400 in hydroxyl number (for example, containing 2-45wt.% of B1 and composed of B1 and a polymeric polyol compound 20-150 in hydroxyl number).
NAKANO YASUHIKO
KAMEMURA ICHIRO
