Abstract: A solid component of catalyst for the (co)polymerization of ethylene is composed of a silica carrier and a catalytically active part including titanium, magnesium, chlorine and alkoxylic groups and is obtained: by suspending an activated silica in a solution of magnesium chloride and titanium tetraalcoholate in a liquid aliphatic acid ester; eliminating the aliphatic acid ester from the resulting suspension to recover a solid; and making this solid react with an aluminium alkyl chloride. It is preferable to add also some measured quantities of a silicon halide to the solution in aliphatic acid ester.

Abstract: A solid component of catalyst for the (co)polymerization of ethylene is composed of a silica support and of a catalytically active part containing titanium, magnesium, chlorine and alkoxy groups, and is obtained by:(i) activating a silica support by contact with a solution of magnesium dialkyl, or magnesium alkyl chloride, in a liquid, aliphatic hydrocarbon solvent;(ii) impregnating the activated silica with a solution, in a liquid aliphatic or aromatic ester, of titanium tetrachloride and tetra-alkoxide in equimolecular or almost equimolecular quantities, and magnesium chloride; and(iii) treating the solid obtained in step (ii) with a proportioned quantity of aluminium alkyl sesquichloride.

Abstract: Solid component of catalyst for the (co)polymerization of ethylene, including magnesium, halogen and titanium, obtained by:(i) dissolution, in an inert organic solvent, of a magnesium dialkyl, or a magnesium alkyl halide, a tin halide (IV) and possibly also an alkyl halide and their contact until a granular solid precipitates from the solution;(ii) contact of said granular solid and its interaction with a titanium halide, alkoxide or halo-alkoxide, to form a solid component of catalyst.

Abstract: A supported Ziegler-Natta catalyst active in ethylene polymerization and in the copolymerization of ethylene with alpha-olefins consists of:(A) a cocatalyst in the form of an organometallic compound of aluminium, and(B) a solid catalyst component obtained by:(i) impregnating a granular solid support with a solution of a titanium alcoholate and magnesium chloride in a liquid aliphatic hydrocarbon, followed by evaporation of the hydrocarbon solvent;(ii) impregnating the support treated in (i) with a solution of magnesium chloride in a liquid aliphatic ester, followed by evaporation of the ester solvent; and(iii) activating the support treated in (ii) by contact with an alkyl aluminium halide.In a preferred embodiment, measured quantities of a silicon halide are introduced in stage (i) and/or (ii), this considerably improving catalytic activity.

Abstract: A solid component of catalyst for the (co)polymerization of ethylene, including magnesium, halogen and titanium, is prepared:(i) by dissolving a magnesium dialkyl, a silicon halide and at times also an alkyl halide, in an inert organic solvent and maintaining contact until a granular solid precipitates;(ii) putting this granular solid in contact and making it react with a titanium halide, alkoxide or halogen-alkoxide, to produce a solid component of catalyst; and(iii) activating this solid component of catalyst by contact with aluminium alkyl halide, if a titanium alkoxide or halogen-alkoxide has been used in phase (ii).

Abstract: A process for the preparation of a solid component of a catalyst active in the (co)polymerization of ethylene and able to form (co)polymers of ethylene having from middle to wide distribution of molecular weight and monomodal distribution of molecular weights, in processes operating in a single step, in suspension or in the gaseous phase. Said solid component of a catalyst contains magnesium, chlorine, silicon, titanium and at least another transition metal on a solid, granular and porous carrier and is obtained by treating the carrier, in succession, with: a compound of a metal selected from hafnium, zirconium or vanadium; a magnesium dialkyl or magnesium alkyl halide; a silicon chloride; and a titanium compound.

Abstract: A solid component of catalyst for the (co)polymerization of ethylene is composed of a silica carrier and a catalytically active part which includes titanium, magnesium, chlorine and also alkoxy groups, and is obtained: by suspending an activated silica in an ethanolic solution of magnesium chloride; by contact of the suspension with an alkoxy or halogen alkoxyde of titanium and with a silicon halide; by eliminating the ethanol from the resulting suspension in order to recover a solid matter; and by making this solid react with an aluminium alkyl chloride.

Abstract: A solid component of a catalyst for the (co)polymerization of ethylene is composed of a silica carrier and a catalytically active part which includes titanium, magnesium, chlorine and also alkoxy groups, and is obtained: by suspending an activated silica in an ethanolic solution of magnesium chloride; by contact of the suspension with an alkoxy or halogen alkoxyde of titanium and with a silicon halide; by eliminating the ethanol from the resulting suspension in order to recover a solid matter; and by making this solid react with an aluminum alkyl chloride.

Abstract: A solid catalyst component for ethylene (co)polymerization, consisting of a particulate silica support and a catalytically active part containing titanium, magnesium, chlorine and alkoxy groups is obtained by a) preparing a solution of magnesium chloride in ethanol; b) impregnating particulate silica with said solution; c) eliminating the unabsorbed ethanol from the suspension; d) eliminating absorbed ethanol from the solid; e) interacting the resultant solid with a titanium chloride, alkoxide or chloroalkoxide; and possibly interacting with an alkylaluminium chloride. In a preferred embodiment in stage e), a silicon halide is added to improve the catalyst activity.