CONTINUOUS METHOD FOR PRODUCING POLYURETHANE HAVING THERMOPLASTIC PROCESSABILITY

摘要

PROBLEM TO BE SOLVED: To provide an industrially simple and economically favorable continuous process that can produce a uniform and nontacky thermoplastic polyurethane elastmer (TPU) having easy processability. SOLUTION: The continuous method for producing a polyurethane having an improved process characteristic and thermoplastic processability from various polyols comprises several steps of (a) forming a prepolymer I by reacting at least one kind of organic diisocyanates (A) and a polyol 1 (B), (b) forming a prepolymer II by reacting the prepolymer I obtained in (a) and a polyol 2 (C) different from the polyol 1 and (c) reacting thoroughly the prepolymer II obtained in (b) and at least one polyol or polyamine of low molecular weight acting as a chain extender (D) in a reactor handling a viscous liquid operated at a high shearing energy. COPYRIGHT: (C)2004,JPO