Perfluorinated polyimides, perfluorinated polyamic acid, starting materials for this purpose, and method for their preparation

摘要

PURPOSE: To obtain a totally fluorinated polyimide having heat-resistance and low light transmission loss over the whole wavelength range for optical communication by thermally cyclizing a totally fluorinated polyamic acid derived from a fluorinated tetracarboxylic acid anhydride and a fluorinated diamine. ;CONSTITUTION: The objective totally fluorinated polyimide containing the recurring unit of formula I {R₁ is tetravalent organic group [preferably the group of formula II (R_f is F, perfluoroalkyl, perfluoroaryl, etc.), etc.]; R₂ is bivalent organic group; the chemical bond between C and the univalent element in R₁ and R₂ is exclusively C-F bond} can be produced by synthesizing a totally fluorinated polyamic acid from (A) an acid anhydride such as 1,4-bis(3,4- dicarboxytrifluorophenoxy)tetrafluoro-benzene dianhydride and (B) a diamine such as tetrafluoro-1,3-phenylenediamine and thermally cyclizing the polyamic acid.;COPYRIGHT: (C)1993,JPO&Japio