abstract |
(57) [Problem] To provide a polyurethane useful as a strength material having high strength and low shrinkage in a low temperature range of -100 ° C or lower. SOLUTION: (1) Polyisocyanate and (3) 9,9- After reacting with a polyol other than bis (4- (2-hydroxyethoxy) phenyl) fluorene [BPEF], (2) BPEF is reacted as a chain extender. |