Patent ID: 7365137

Claim:
A process for the polymerization of olefins of formula CH 2 ═CHR, wherein R is hydrogen or an alkyl, cycloalkyl or aryl radical with 1-20 carbon atoms, comprising the following steps: a) a first step of polymerization wherein at least one of said olefins are polymerized, in at least one reactor, in the presence of a catalyst comprising the product of reaction between an alkyl-Al compound and (i) a solid component comprising a compound of a transition metal M I selected from the group consisting of Ti and V, not containing M I -π bonds, and a halide of Mg in active form, or (ii) a Phillips catalyst to produce an olefin homo- or copolymer; b) a treatment step comprising: I. contacting the polymer produced in polymerization step a) with compounds that deactivate the catalyst used in said step a); and II. contacting the product obtained in I. with a solution comprising a compound of formula (I): wherein: Ti is titanium; L is a group bonded to Ti through a π-bond; Y is a moiety comprising nitrogen, phosphorus, sulfur or oxygen through which Y is covalently bonded to both Z and Ti; Z is a moiety bridging L and Y, X, same or different, are monovalent anionic moieties having up to 30 non-hydrogen atoms provided that, if X is an aromatic group, it is not bonded to Ti through a π-bond, optionally two X groups being covalently bonded together to form a divalent dianionic moiety having both valences bonded to Ti; and, optionally, with an activating cocatalyst in hydrocarbon solvents; and c) a second step of polymerization wherein at least one olefin is polymerized, in at least one gas phase reactor, in the presence of the product obtained in the treatment step b); and wherein the amount of homo- or copolymer of olefins produced in the first polymerization step a) is between 10% to 90% by weight of the total amount of polymer produced.