| 摘要 |
PROBLEM TO BE SOLVED: To provide a low density polyethylene insulated wire excellent in electrical and mechanical characteristics, for use in a coaxial cable for transmitting high frequency signals, etc., and a method for manufacturing the same. SOLUTION: In a low-density polyethylene insulated wire having both a fill layer made from an ethylene-α-olefin copolymer and an outer layer made from low density polyethylene on a conductor, (1) the ethylene-α-olefin copolymer is copolymerized by use of a single-site catalyst; (2) its density and melt mass- flow rate are 0.88 to 0.94 g/ml and 0.3 to 10 g/10 minutes, respectively; (3) the amount S% by which the copolymer is extracted into 50 deg.C n-hexane, its density Dg/ml, DSC melting point M deg.C, and density Dg/ml meet the relations shown by the formulae: S<=-47.18×D+44.56 and M<=649.6×D-484.9. The ethylene-α- olefin copolymer forming the fill layer is extruded at die extrusion temperatures of 100 to 280 deg.C and at an extrusion rate of 200 to 1000 m/min to cover the wire.
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