Abstract: The present invention relates to an impact modifier and a device and a method for the production thereof, as well as to a method for preparing a thermoset material, or a thermoset material precursor, from the impact modifier. The impact modifier comprises at least one copolymer selected from A-B-A, A-B, and A-B-C block copolymers in which: each block is linked to the other by means of a covalent bond or an intermediate molecule that is connected to one of the blocks by a covalent bond and to the other block by another covalent bond; A is a PMMA homopolymer or a copolymer of methyl methacrylate, A preferably being compatible with the resin; C is either (i) a PMMA homopolymer or a copolymer of methyl methacrylate, or (ii) a polymer based on monomers or a mixture of vinyl monomers, and blocks A and C are identical; and B is incompatible or partially compatible with the thermoset resin and incompatible with block A and optional block C.

Abstract: 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.

Abstract: This process for preparing a catalyst support for the homopolymerization or copolymerization of ethylene and &agr;-olefins is characterized in that at least one organochlorine compound and a premix of at least one alkylmagnesium and of at least one organoaluminum compound chosen from aluminoxanes, aluminosiloxanes and alkylaluminums are reacted together, in the presence of at least one aliphatic diether as electron donor.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a process for the manufacture of a solid catalytic component for the polymerization or copolymerization of olefins, resulting in a polymer or copolymer with broadened molecular mass distribution. The process includes a first stage including bringing into contact a) a solid support including at its surface at least 5 hydroxyl groups per square nanometre (OH/nm2) and b) an organic magnesium derivative, and optionally, preferably, c) an aluminoxane, to obtain a first solid, and then a second stage including bringing the first solid and a chlorinating agent into contact to obtain a second solid and then, in a later stage, impregnation of the second solid with a transition metal derivative.

Abstract: 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.

Abstract: 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.