Elf Atochem S.a.

Atochem

Atofina

Jean-Loup Lacombe

Claude Brun

Jean Malinge

Thierry Saudemont

Daniel Cochard

Henri Violle

A process is provided for preparing a catalyst support for polymerizing &agr;-olefins comprising the steps of: (i) reacting, in the presence of a first electron donor, a chlorine-containing organic compound and a prior mixture of an alkylmagnesien and an aluminoxane and/or aluminosiloxane and/or alkylaluminum and, optionally, a second electron donor; and (ii) activating a product from step (i) in suspension in an inert liquid by means of an activation electron donor, together with the support thus obtained, a catalyst for polymerizing &agr;-olefins, comprising this catalyst support and a group IV transition metal halide, and a process for polymerizing &agr;-olefins, particularly propylene, comprising contacting the &agr;-olefin with the catalyst.

Process for preparing a catalyst support for polymerization of &agr;-olefins, and support thus obtained

A copolymer of ethylene and an alpha-olefin contains from 3 to 12 carbon atoms, wherein 0.1 to 1.5 mol % of the units originate from the alpha-olefin. The copolymer has a relative density ranging from 0.960 to 0.940, a transition metal content lower than 6 ppm, an Mw/Mn ratio higher than 7, an Mz/Mw ratio higher than 3.3 and an Mz higher than 300,000. The copolymer is prepared from the polymerization or co-polymerization of at least one olefin in the presence of a solid catalytic component or a prepolymerized catalyst.

Olefin polymer or copolymer formed using a solid catalytic component

Process for preparing a catalyst support for polymerization of alpha-olefins, and support thus obtained

Catalytic component and its use in olefin polymerization

A process for preparing a transition metal component for a catalyst system wherein a specified aluminosiloxane derivative is reacted with a monohalopenated, alkylated, or alkoxylated compound of magnesium and the reaction product is chlorinated and reacted with a transition metal; a catalyst system comprising such transition metal component and a cocatalyst selected from organometallic compounds of a metal of Groups I through III of the Periodic Table; and the process of synthesizing olefin homopolymers and copolymers utilizing such catalyst system.

Process for preparing a catalyst component, resultant catalyst system,

A process for preparation of a transition metal component of a catalytic system for the polymerization of olefins, wherein an organo-magnesium-aluminum reaction product is formed by bringing into contact, a halogenated, alkylated or alkoxylated magnesium compound with an organo-aluminum compound, then subjecting the reaction product to a chlorination and to a treatment by a compound of a transition metal such as Ti, V, Zr and Cr. As an organo-aluminum compound there is used one or several aluminoxane compounds of the formula ##STR1## wherein R' is an alkyl or from C.sub.1 to C.sub.16, the R's form together a radical --O-- or designate each a radical R' and n is an integer of from 0 to 20. The transition metal component obtained can be used in combination with a co-catalyst and eventually an electron donor to form a catalytic system apt to polymerize the alpha-olefins.

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Artiguelouve, France

Jean-Loup Lacombe