Electrical Insulation System Based on Epoxy Resins for Generators and Motors

Abstract

Disclosed is an anhydride-free insulation system for current-carrying construction parts of an electric engine which comprises: (A) a mica paper or mica tape for wrapping parts of said electric engine that are potentially current-carrying during operation of the engine, which mica paper or mica tape is impregnable via vacuum pressure impregnation with a thermally curable epoxy resin formulation and comprises a complex of boron trihalogenide with an amine of the formula BX3·NR1R2R3 or R1R2N—A—NR1R2, wherein X denotes halogen, R1, R2 and R3 are each independently of the others hydrogen, C1-C12alkyl, C5-C30aryl, C6-C36aralkyl or C6-C14cycloalkyl, which can be unsubstituted or substituted by one or more C1-C12alkyl groups, A is a bivalent aliphatic aromatic or cycloaliphatic radical; (B) a thermally curable bath formulation for the vacuum pressure impregnation comprising bisphenol A diglycidyl ether and optionally bisphenol F diglycidyl ether, which formulation is substantially or, preferably, entirely free of thermally activatable curing initiators for the epoxy resin formulation.

Dependencies are inferred from the claim text.