ETHYLENE COPOLYMERS, PROCESS FOR THE PREPARATION OF ETHYLENE-BASED POLYMERS AND CATALYST SYSTEM USED THEREIN

摘要

Ethylene copolymers are prepared with comonomers selected from (a) .alpha.olefins, (b) cycloolefins and (c) polyenes, with a content of ethylene units of between 80 and 99 mol %, a content of units derived from .alpha.-olefin, cycloolefin and/or polyene comonomers of between 1 and 20 mol %, characterized in that: (a) in TREF (Temperature Rising Elution Fractionation) analysis, a quantity equal to at least 90 % by weight of the copolymer is eluted within a temperature interval of less than 50 ~C, and (b) Mw/Mn > 3, where Mw is the weight-average molecular weight and Mn is the number-average molecular weight, both determined by means of GPC.