| abstract |
PROBLEM TO BE SOLVED: To provide a polyurethane having heat resistance (high glass transition point), film forming ability and high refractive index. SOLUTION: A polyurethane having a repeating unit represented by the following formula (1) and having a weight average molecular weight of 2,000 to 300,000. A 1 and A 2 are the same or different and each represent a hydrogen atom or a methyl group, and R represents a naphthalene ring or a decalin ring. It can be obtained by reacting 9,9-bis (4- (2-hydroxyalkoxy) phenyl) fluorene with diisocyanates in the presence or absence of a solvent. Embedded image |