PURPOSE: To obtain an electric apparatus which uses an electric coil not impregnated in varnish by winding an enameled wire wherein a conductor is coated with polyol, an inner insulation film and an outer insulation film one after another and installing the coil in the apparatus.
CONSTITUTION: Polyol can be obtained by transesterifying and polycondensing polyhydric alcohol wherein the molecular structure has an urethane bonding and polyhydric carboxylic acid in an organic solvent. An inner insulation film is made of an insulation paint wherein the main element is clock polyhydric isocyanate wherein the NCO group against the residual OH group in polyol has an NCO/OH equivalent ratio of 1 or more and preferably nearly 1. An outer insulation film is made of an insulation paint wherein the main element is polyamide or epoxy denatured polyurethane. These three materials are coated on a conductor one after another and a finished enameled wire is wound into a coil and installed in an apparatus. This enables to obtain an electric apparatus which uses an electric coil not impregnated in varnish.
KONISHI TADAAKI
UMEHARA KOUICHI
YASUTOMI SATOSHI
TOKYO ELECTRIC CO LTD