| 摘要 |
PURPOSE:To control generation and development of a water tree phenomenon by mixing polyolefin resin with conductive carbon black to set the volume resistivity and saturated water absorption of the semiconductive layer at specific values. CONSTITUTION:Semiconductive layers 3, 5 are installed at the internal and external sides of the insulator 4 of a power cable 1 by extrusion. The semiconductive layers 3, 5 are made by mixing conductive carbon black in polyolefin resin suck that the volume resistivity of the layers is 10<5>OMEGA-cm or less and their saturated water absorption, 1000ppm or less. Moreover, 5-10 parts by weight of conductive carbon black whose specific surface is m<2>/g or more is mixed in 100 parts by weight of high pressure processed low density polyethylene or low pressure processed straight chain low desity polyethylene in the case of the semiconductive layers 3, 5. |
