| 摘要 |
PURPOSE:The titled crosslinked copolymer excellent in impulse breakdown resistance, AC breakdown resistance, inhibition of deterioration due to water tree, flexibility, etc., comprising a crosslinked copolymer of ethylene with an ethylenically alpha,beta-unsaturated benzophenone derivative. CONSTITUTION:An ethylene copolymer of a number-average MW >=1,000 is obtained by radical-polymerizing ethylene with 0.00065-1.3mol% ethylenically alpha,beta-unsaturated benzophenone derivative of the formula (wherein R is H or -CH3 and n is 0 or 1) at a temperature >=120 deg.C and a pressure >=500kg/cm<2> in the presence of a catalyst, e.g., 1-butyl peroxyisopivalate. 100pts.wt. this copolymer is mixed with 0.5-4pts.wt. chemical crosslinking agent (e.g., dicumyl peroxide) and crosslinked to obtain an electrical-insulating crosslinked ethylene copolymer having a benzophenone derivative group unit content of 0.005-10mol% and a gel content (according to the method of measurement as stipulated by JIS C3005) >=40%. |
