Patent ID: 6613983
Filing Date: 2003-09-02
Classification: H01B

Abstract:
A method of manufacturing a foamed-polyolefin-insulated wire comprising a conductor having a diameter of 0.4 mm or less and an insulation layer having a thickness of 0.8 mm or less, wherein the wire has the following properties:(a) an equivalent dielectric constant of less than 1.6; (b) a fluctuation of the equivalent dielectric constant within a range of Â±0.1; and (c) conductor stripping force of 100 g/50 mm or more, wherein the insulation layer comprises a polyolefin having at least 10 weight % of a partial metal salt of a copolymer having a comonomer selected from the group consisting of carboxylic acid and a carboxylic anhydride group, wherein the partial metal salt of a copolymer is a partial metal salt of a copolymer of ethylene and a carboxylic acid or a carboxylic anhydride; the method comprising: extruding a polyolefin having a swelling ratio of 55% or more over the conductor to form a foamed insulation layer having a foaming degree of 50% or more, wherein the polyolefin comprises at least one member selected from the group consisting of a chemical foaming agent and an inert gas.