Components of catalysts for the polymerization of olefins

摘要

Catalysts useful in the polymerization of olefins, more particularly of ethylene and mixtures thereof with alpha-olefins and/or diolefins, are disclosed. The new catalysts are obtained by mixing a halide of titanium or vanadium in which the metal has a valency lower than 4, with a support comprising an anhydrous magnesium or zinc halide in an active form under particular conditions, and then activating the resulting product with a hydride or organometallic compound of a metal belonging to Groups I to III, inclusive, of the Mendelyeev Periodic System.