Bp Chemicals Limited

Commissariat a L'energie Atomique

Christine Jacqueline Chabrand

Jean-Claude A Bailly

Erick Dominique Daire

Ian Raymond Little

John Paul McNally

Philippe Bres

Caroline Mladenov

Jean P Gauchon

Muriel Esteban

Brunel Guy

A process for the gas-phase (co-)polymerization of olefins in a fluidised bed reactor using a Ziegler-Natta type catalyst characterised in that the polymerisation is performed in the presence of an additive having the formula R&#x2014;Cl where R is an alkyl group of 2 to 7 carbon atoms.

Process for the gas-phase (co-)polymerization of olefins in a fluidized bed reactor

Catalyst compositions comprising metallocene complexes having polymerisable olefinic groups substituent on an organic group containing a cyclopentadienyl nucleus may be used for the preparation of polyolefins. The catalyst compositions may be in the form of polymers comprising the metallocene complex and may be suitably supported on inorganic supports. Polymers having a broad range of density and melt indices as well as low hexane extractables and excellent powder morphology and flowability may be obtained by use of the catalyst compositions. Preferred metallocene complexes are zirconium complexes in which the polymerisable olefinic group is vinyl.

Catalyst compositions and process for preparing polyolefins

Catalyst compositions comprising metallocene complexes having polymerisable may be used for the preparation of polyolefins. The catalyst compositions may be in the form of polymers comprising the metallocene complex and may be suitably supported on inorganic supports. Polymers having a broad range of density and melt indices as well as low hexane extractables and excellent powder morphology and flowability may be obtained by use of the catalyst compositions. Preferred metallocene complexes are zirconium complexes in which the polymerisable group is vinyl.

The present invention relates to a solid catalyst suitable for polymerizing olefins in a heterogeneous process, the catalyst consisting of spheroidal particles having a narrow particle size distribution and comprising (i) a support containing magnesium dichloride and an electron-donor free from labile hydrogene, (ii) a zirconium metallocene, and (iii) optionally an organoaluminium compound which is an aluminoxane preferably. The solid catalyst may be used in the form of a prepolymer comprising a polyethylene or a copolymer of ethylene and an active zirconium metallocene catalyst essentially consisting of atoms of Zr, Mg, Cl and Al, preferably in the form of spheriodal particles. The solid catalyst or the prepolymer may be used for producing polyethylene or copolymer of ethylene having from 0.5 to 20 ppm of Zr and a molecular weight distribution from 2 to 5, in the form of a powder having a bulk density from 0.3 to 0.55 g/cm.sup.3, preferably consisting of spheroidal particles.

Catalyst and prepolymer used for the preparation of polyolefins

The present invention relates to a solid catalyst suitable for polymerizing olefins in a heterogeneous process, the catalyst consisting of spheroidal particles having a narrow particle size distribution and comprising (i) a support containing magnesium dichloride and an electron-donor free from labile hydrogen, (ii) a zirconium metallocene, and (iii) optionally an organoaluminium compound which is an aluminoxane preferably. The solid catalyst may be used in the form of a prepolymer comprising a polyethylene or a copolymer of ethylene and an active zirconium metallocene catalyst essentially consisting of atoms of Zr, Mg, Cl and Al, preferably in the form of spheriodal particles. The solid catalyst or the prepolymer may be used for producing polyethylene or copolymer of ethylene having from 0.5 to 20 ppm of zr and a molecular weight distribution from 2 to 5, in the form of a powder having a bulk density from 0.3 to 0.55 g/cm.sup.3, preferably consisting of spheroidal particles.

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Martigues, France

Christine Jacqueline Chabrand