Patent ID: 6214948
Filing Date: 2001-04-10
Classification: C08F,Y10S

Abstract:
A process for the polymerization of at least one olefin, in which a catalytic system is used, said catalytic system prepared by placing a solid precursor in contact with an organometallic compound derived from a metal chosen from groups IA, IIA, IIB, IIIA and IVA of the Periodic Table, said solid precursor containing at least one neutral metallocene derived from a transition metal and (b) at least one ionizing agent, selected from the group consisting of (b1) ionic compounds comprising a cation having Lewis acid properties and which ionizes the neutral metallocene and an anion which is inert towards an ionized metallocene and which stabilizes the said ionized metallocene and (b2) nonionic compounds having Lewis acid properties and converts the neutral metallocene in to a cationic metallocene, wherein the neutral metallocene (a) is in the halogenated state, the transition metal being linked to at least one halogen atom, said solid precursor being obtained by mixing the halogenated neutral metallocene with the ionizing agent in a heterogeneous medium wherein at least 80% of at least one of these two compounds is in the solid state.