| 摘要 |
PURPOSE:To provide an insulated wire wherein foaming degree is high and heat resistance is excellent by covering the surface of a wire with specific polypropylene or polypropylene blended with a foaming agent. CONSTITUTION:The surface of an electric conductor such as an Sn plated Cu wire is extrusion-covered directly or via another insulating material by polypropylene containing -(CH2)n-CH=CR2 (wherein R represents a polar group such as H, CH3, C2H5, OH, COOH) in a side chain thereof. Or, the surface of the electric conductor is extrusion-covered by a blend in which 100 parts by weight of polypropylene containing -(CH2)n-CH=CR2 (wherein R represents a polar group such as H, CH3, C2H5, OH, COOH) in a side chain thereof is blended with 5-20 parts by weight of azodicarbonamide as a foaming agent, and then irradiated with an electron beam. An insulated wire having excellent heat resistance and a low dielectric constant due to foaming can be thereby obtained. |
