POLYIMIDE RESIN VARNISH, INSULATED ELECTRIC WIRE USING SAME, ELECTRIC COIL, AND MOTOR

摘要

Provided is a polyimide resin varnish capable of forming an insulating layer having high inter-layer adhesion, high adhesion to a conductor, and excellent processing resistance. Also provided is an insulated electric wire having excellent processing resistance, heat resistance, and mechanical properties. The polyimide resin varnish has as the main component thereof a polyimide precursor resin obtained by reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride. The imide group concentration of the polyimide precursor resin after imidization is 28.0%-33.0%.