| abstract |
Polymer repeat units derived by contacting 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BDPA) and 2,2'-bis (trifluoromethyl) benzidine (TFMB) monomers are at least Perfluorinated polyimide (and copolyimide) compositions, in particular films, comprising 50 mole percent. The perfluorinated polyimide (and copolyimide) films of the present invention have an in-plane coefficient of thermal expansion (CTE) of -5 to +20 ppm / ° C (based on 75-micron thick films) and an average light transmittance of about 65.0 to About 99.0. Films of the present invention may provide desirable properties because they convert polyimides using chemical conversion methods instead of the thermal conversion processes typically employed. The film of the present invention is excellent as a substrate in an optical display device, and can be used in place of a rigid glass substrate. The polyimide film of the present invention may also be used to manufacture flexible display devices (eg, mobile phones, personal digital assistants, portable video game consoles, laptops, etc.).n n n 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BDPA), 2,2'-bis (trifluoromethyl) benzidine (TFMB) monomer, perfluorinated polyimide, light transmittance, chemical Switching method, optical display device. |