| abstract |
Novel polyurethane compositions having excellent bond strength, thermal resistance and resistance to hot water are provided by a polymeric polyol and an organic polyisocyanate at a hydroxyl group/isocyanate group equivalent ratio (NCO/OH) of 1 to 10, wherein said polymeric polyol is a polyurethane polyol prepared from a polyester polyol and an organic diisocyanate, said polyurethane polyol having a number average molecular weight of 3,000 to 50,000, said polyester polyol being composed of the following structural unitthe following dicarboxylic acid structural unitwherein n is an integer from 1 to 12, and the following dicarboxylic acid structural unitwherein Ar is the divalent residue of an aromatic hydrocarbon of 6 to 10 carbon atoms, and the molar ratio of structural unit (II) to structural unit (III) being in the range from 1/5 to 5/1, and said polyester polyol having a number average molecular weight of 600 to 8,000. |