| 摘要 |
PURPOSE: To improve water resistant tree performance even if a defect is caused in an insulator by blending a styrene-maleic anhydride copolymer by a prescribed quantity with a polyethylene or ethylene type copolymer or the like. CONSTITUTION: A styrene-maleic anhydride copolymer is blended with a polyethylene or ethylene type copolymer or a mixture of these grafted so that the content of maleic anhydride becomes 0.02wt.% to 5wt.%, so that the content of styrene becomes 0.05wt.% to 10wt.%, and an electric insulating composition is obtained. Since this composition is used, even if there exists a defect such as a void in insulation, a foreign matter and nonuniformity of an interface between an insulator and a semiconductive layer, water resistant tree performance, particularly, bow-tie tree performance is improved while having an electric characteristic equal to or more than usual. |
