New class H heat resistant magnet wire enamel

A new polyamideimide-ester resin (PAIE) has been developed by the reaction between polyamideimide macromer, polyfunctional carboxylic acids and polyfunctional alcohols. The molecular structure of the PAIE consists of polyamideimide chain which exhibits excellent heat resistance, physical and chemical properties, and a polyester chain which exhibits good flexibility and solubility in conventional solvents. The magnet wire enamel prepared from the PAIE exhibits excellent thermal stability as a class H magnet wire and is superior to that of polyesterimide at deterioration resistance, Overload resistance, refrigerant resistance and heat shock resistance.