6,6-Polyimide Copolymers and Processes for Preparing Them

摘要

The present invention provides a process for preparing a solvent-soluble polyimide copolymer synthesized from a 6,6-imide segment having an imide oligomer with PMDA at both ends produced by adding 4 molar equivalents of pyromellitic dianhydride (PMDA) and 2 molar equivalents of diaminotoluene (DAT) to an imide oligomer produced by heating 1 molar equivalent of biphenyltetracarboxylic dianhydride (BPDA) and 2 molar equivalents of diaminodiphenyl ether (DADE) at 160-200° C. in the presence of a catalyst in an organic polar solvent.