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.