Perfluorinated polymide, perfluorinated poly (amic acid), starting compounds therefor, and methods for preparing them

Abstract From the Canadian patent

A perfluorinated polyimide comprising a repeating unit represented by general formula (1): (see fig. I), and a perfluorinated poly(amic acid) comprising a repeating unit represented by general formula (6): (see fig. II), wherein R1 is a tetravalent organic group; and R2 is a divalent organic group, provided that chemical bonds between carbon atoms and monovalent elements contained in R1 and R2 are exclusively carbon-to-fluorine bonds; methods for preparing them; and optical material including the perfluorinated polyimide. 1,4-Bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene dianhydride, 1,4-difluoropyro-mellitic anhydride, 1,4-bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene, …