Aromatic polycarbodiimide and film thereof

摘要

A polycarbodiimide having excellent heat resistance and humidity resistance, which comprises a structural unit represented by the following formula (A) wherein R represents a divalent organic group represented by any one of the following formulae (I) and (II), n is an integer of 2 to 400 wherein X1 to X4 independently represent a hydrogen or an alkyl group having 1 to 3 carbon atoms.