Metallocene catalyst for the (CO)polymerization of alpha -olefins

摘要

A catalyst active in the (co)polymerization of alpha -olefins is obtained by putting the following components in contact with each other: (i) a "bridged" bis-metallocene derivative of a metal M selected from titanium, zirconium or hafnium, wherein the divalent "bridge" has a rigid structure linked to two eta 5-cyclopentadienyl ring with two methylene groups having a distance from each other of less than 3.5 ANGSTROM ; (ii) a co-catalyst consisting of an organic derivative of a metal M' selected from boron, aluminium, gallium and tin. Such a catalyst allows high polymerization rates to be reached and is particularly suitable for high temperature polymerization process and co-polymerization of ethylene with other alpha -olefins.