| 摘要 |
PURPOSE:To obtain an ethylene copolymer suitable as a coating material for superhigh voltage wire cables excellent in dielectric breakdown characteristics, retention of performance, flexibility, etc., by copolymerizing ethylene with a specified alpha,beta-ethylenically unsaturated acid ester. CONSTITUTION:This ethylene copolymer comprises ethylene and 0.005-10mol%, based on the total copolymer, alpha,beta-ethylenically unsaturated acid halophenyl ester of formula I or II (wherein R is H or methyl, X is F, Cl, Br or I and n is 1-5). Said monomers are copolymerized together at a temperature >=120 deg.C and a pressure >=500kg/cm<2> in the presence of a free radical-generating initiator. As the reactor, a tank reactor is desirable because a copolymer of a uniform composition can be obtained. The number-average MW of the copolymer is at least 1,000, particularly preferable to be at least 3,000. |
