Elastomeric copolymers of ethylene with alpha-olefins and process for their preparation

摘要

Amorphous copolymers of ethylene with alpha -olefins and optionally minor amounts of polyenes are disclosed, having the following characteristics: (A) the % by mole content of alpha -olefin in the copolymer (% alpha ) and the ratio between the molar amount of alpha -olefin diads and the molar content of alpha -olefin in the copolymer ( alpha alpha / alpha ) satisfy the following relationship: (% alpha ) - 250 ( alpha alpha / alpha ) >/= 10 (B) less than 2% of the CH2 groups in the polymeric chain are in sequences (CH2)n, wherein n is an even number. These copolymers are obtainable by operating in the presence of particular metallocene-based catalysts having two fluorenyl groups joined together through a bridging group.