Insulated electric wire and process for producing the same

Abstract

A process for producing an insulated electric wire, comprising the steps of coating around a conductor an energy radiation curable resin composition having heat expansible microspheres incorporated therein, and curing the energy radiation curable resin composition thus coated on the conductor by exposure to an energy radiation. The process also comprises the step of heating the energy radiation curable resin composition to expand the heat expansible microspheres in the energy radiaiton curable resin composition, thereby forming a high-porosity insulation layer on the conductor. An insulated electric wire comprises a conductor; an energy radiation curable resin composition layer having microspheres incorporated therein and surrounding the conductor, the outside diameter of the microspheres in the energy radiation curable resin composition layer being maximum in the vicinity of the conductor and decreasing gradually toward the periphery of the energy radiation curable resin composition layer.

Dependencies are inferred from the claim text.