| 摘要 |
PROBLEM TO BE SOLVED: To decrease melt fracture, critical surface misalignment, or generation of electric torry and obtain a long service life by providing an internal semiconductor layer, two layers i.e., insulation layer and external semiconductor layer of a specific resin composition, and an external semiconductor layer on a conductor and performing heating cross-linking after coating. SOLUTION: Each resin composition of an internal semiconductor layer, insulation layers A and B, and an external semiconductor layer is coated using a common four-layer extruder on a conductor, and heating cross-linking is performed on a conductor. Here, an insulation layer A is made of resin composition containing 100wt.% of a high-pressure method diverged low density ethylene based resin of 0.915 to 0.912g/cm<3> and of 0.3 to 3.0g/10 minutes in melt index and 0.1 to 5wt.% of organic peroxide. An insulation layer B contains 100wt.% of a straight chain shaped low density ethylene-α-olefin copolymerαof 0.91 to 0.93g/cm<3> in density and 0.1 to 5.0g/10 minutes in let index and 0.3 to 3wt.% of organic peroxide. In addition, the relationship between thickness a and thickness b of the insulation layers A and B is a<=b<=(1/2)a. Thus, misalignment of each boundary is eliminated, and longer service life is obtained.
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