PRODUCTION OF AROMATIC POLYAMIC ACID

摘要

PURPOSE:To produce a high-molecular arom. polyamic acid from biphenyltetracarboxylic dianhydride obtd. by dehydrating biphenyltetracarboxylic acid. CONSTITUTION:Biphenyltetracarboxylic dianhydride which is obtd. by dehydrating biphenyltetracarboxylic acid and has a total content of biphenyltricarboxylic acid and its anhydride lower than 0.2wt.% is used in the process for producing an arom. polyamic acid by copolymerizing biphenyltetracarboxylic dianhydride with an arom. diamine.