Patent ID: 6451726
Filing Date: 2002-09-17
Classification: C08F,Y10S

Abstract:
Catalyst component for the polymerization of olefins CH2&boxH;CHR, wherein R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms, comprising the product obtained by contacting a Ti compound of formula Ti(OR)nâˆ’yXy, where R is an alkyl, isoalkyl, cycloalkyl or aryl radical having from 1 to 18 carbon atoms, X is a halogen atom, n is the valence of titanium and y is a number of from 1 to n, with a pre-polymer having a porosity (measured with Hg method) higher than 0.3 cc/g and containing from 0.5 to 100 g of polymer per g of a solid catalyst component, said pre-polymer being obtained by (co)polymerizing an olefin or a diolefin which is (co)polymerizable in the presence of a catalyst comprising the solid catalyst component, the solid catalyst component comprising a transition metal compound selected from the group consisting of Ti compounds of the above formula Ti(OR)nâˆ’yXy, vanadium halides, haloalcoholates and vanadyl halides, and Ti, Zr and Hf compounds containing at least a &pgr;-metal bond, said transition metal compound being supported on a Mg dihalide having a mean crystallite size lower than 30 nm.