| 摘要 |
PROBLEM TO BE SOLVED: To provide a fluorinated polyimide resin being excellent in heat resistance and transparency and having small coefficient of moisture absorption and coefficient of birefringence, and to provide a light waveguide having high transparency in a near infrared wave length area by copolymerizing a mixture of fluorinated naphthalene tetracarboxylic acid anhydride and 4,4'- hexafluoroisopropylidene diphthalic acid anhydride with a fluorinated aromatic diamine compound. SOLUTION: A fluorinated polyimide resin is obtained by copolymerizing a mixture of naphthalene-1,4,5,8-tetracarboxylic acid anhydride and 4,4'- hexafluoroisopropylidene diphthalic acid anhydride expressed by formula I with 2,2'-bis(4-aminophenyl) hexafluoropropane or 2,2'-bis(trifluoromethyl) benzine or 2,2'-bis[4-(4-aminophenoxy) phenyl] hexafluoropropane expressed by formula II. In the formula I, II, R1 to R12 are selected from a group composed of H, CF3, C2F5, C3F7 or C4F9. |
