Abstract: A process for preparing a catalyst component, comprising a Mg compound a Ti compound and an electron donor compound (ED) selected from alcohol, glycols, esters, ketones, amines, amides, nitrites, alkoxysilanes and aliphatic ethers as essential compounds, comprising two or more steps of reaction involving the use of at least one of said essential compounds as fresh reactant alone or in a mixture in which it constitutes the main component, said process being characterized by the fact that in the last of said one or more reaction steps the essential compound used as a fresh reactant is the ED compound.

Abstract: A class of bridged or unbridged metallocene compounds is disclosed, wherein the cyclopentadienyl ligands have two or four adjacent substituents forming one or two alkylenic cycles of from 4 to 8 carbon atoms. These metallocenes are useful as catalyst components for the polymerization of olefins, particularly for the (co)polymerization of ethylene and for the polymerization of propylene.

Abstract: A process for the (co) polymerization of olefins of formula CH2?CHR wherein R is a hydrogen atom, a methyl or an ethyl radical, carried out in the presence of a system comprising (a) solid catalyst component comprising a compound of Ti or V not containing Metal-? bonds, Mg, halogen and optionally an electron donor compound; (b) an Al-alkyl compound; and (c) one or more non-polymerizing olefins in an amount up to 1.2% by mol with respect to the total olefins present in the reactor.

Abstract: A class of bridged or unbridged metallocene compounds is disclosed, wherein the cyclopentadienyl ligands have two or four adjacent substituents forming one or two alkylenic cycles of from 4 to 8 carbon atoms. These metallocenes are useful as catalyst components for the polymerization of olefins, particularly for the (co)polymerization of ethylene and for the polymerization of propylene.

Abstract: Catalyst components for the polymerization of olefins CH2?CHR, wherein R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms, comprising Mg, Ti, Cl, OR groups, where R is a C1-C10 alkyl group optionally containing heteroatoms, and an ether having two or more ether groups, characterized by the fact that the Mg/Ti weight ratio is lower than 3 from 2 to 6.5 the Cl/Ti weight ratio is from 1.5 to 6, the OR/Ti weight ratio is from 0.5 to 3.5 and at least 50% of the Titanium atoms are in a valence state lower than 4. The said catalyst components allow the preparation of ethylene copolymers with a low content of xylene soluble fractions.

Abstract: A process for the (co) polymerization of olefins of formula CH2?CHR wherein R is a hydrogen atom, a methyl or an ethyl radical, carried out in the presence of a system comprising (a) solid catalyst component comprising a compound of Ti or V not containing Metal-? bonds, Mg, halogen and optionally an electron donor compound; (b) an Al-alkyl compound; and (c) one or more non-polymerizing olefins in an amount up to 1.2% by mol with respect to the total olefins present in the reactor.

Abstract: Process for the preparation of ethylene copolymers comprising the copolymerization of ethylene with olefins CH2?CHR, in which R is a hyrdocarbyl radical with 1-12 carbon atoms carried out in the presence of a catalyst comprising (i) a solid catalyst component comprising Mg, Ti, halogen and specific 1,3-diethers of formula (I) in which R is a C1-C10 hydrocarbon group, R1 is methyl or ethyl, optionally containing a heteroatom, and R2 is a C4-C12 linear alkyl optionally containing a heteroatom, and (ii) an organo-Al compound. The obtained copolymers are endowed with good comonomer distribution.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising single carbon bridged metallocenes, which has a particular ligand system containing a heteroatom.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising silicon bridged metallocenes having a particular ligand system containing a heteroatom.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising silicon bridged metallocenes having a particular ligand system containing a heteroatom.

Abstract: Supported catalysts for the polymerization of olefins comprise the following components: (A) a porous organic support functionalised with groups having active hydrogen atoms; (B) an organo-metallic compound of aluminium containing heteroatoms selected from oxygen, nitrogen and sulphur; and (C) a compound of a transition metal selected from those of groups IVb, Vb or VIb of the Periodic Table of the Elements, containing ligands of the cyclopentadienyl type. These supported catalysts, obtainable in the form of spherical particles, can be used in the polymerization reaction of olefins either in liquid or in gas phase, thus producing polymers endowed with a controlled morphology and with a high bulk density.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising silicon bridged metallocenes having a particular ligand system containing a heteroatom.

Abstract: A process for polymerizing ethylene comprising contacting under polymerization condition ethylene and optionally one or more olefins with a catalyst system obtainable by contacting: a bis amido compound of formula (I) wherein Y is Si, Ge and Sn; X is hydrogen, halogen or an hydrocarbon radical; R1, R2, R3, R4, R5 and R6, are hydrocarbon radical; Q is a neutral Lewis base; and m is 0-2; one or more boron activating cocatalysts and one or more aluminum alkyls or alumoxanes.

Abstract: Catalyst system for the polymerization of olefins CH2═CHR, wherein R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms, comprising the product of the reaction between (a) a solid catalyst component comprising Mg, Ti, and halogen, (b) dimethylaluminium chloride (DMAC) and (c) an alkylaluinium compound, in which the molar ratio between (b) and (c) is lower than 10. This kind of catalyst system is particularly suitable for the preparation of copolymers of ethylene with &agr;-olefins due to its high capacity for incorporating the comonomer while at the same time maintaining high yields.

Abstract: Zirconocene compounds with two indenyl ligands linked in the 2 position by means of a two-carbon-atoms divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. Particularly it is possible to prepare, with high yields, ethylene (co)polymers having low molecular weights and narrow molecular weight distributions, without the need of using considerable amounts of molecular weight regulators, such as hydrogen.

Abstract: Ethylene copolymers are prepared with comonomers selected from: (a) &agr;-olefins, (b) cycloolefins and (c) polyenes, with a content of ethylene units of between 80 and 99 mol %, a content of units derived from &agr;-olefin, cycloolefin and/or polyene comonomers of between 1 and 20 mol %, characterized in that: (a) in TREF (Temperature Rising Elution Fractionation) analysis, a quantity equal to at least 90% by weight of the copolymer is eluted within a temperature interval of less than 50° C., and (b) Mw/Mn>3, where Mw is the weight-average molecular weight and Mn is the number-average molecular weight, both determined by means of GPC.

Abstract: Supported catalysts for the polymerization of olefins comprise the following components:

Abstract: Processes for the polymerization of olefins in which late transition metal complexes, such as nickel, iron, cobalt and palladium complexes, are used as a polymerization catalyst have improved polymer productivity when oxidizing agents are present during at least a portion of the polymerization. The polymers produced are useful as elastomers, for packaging films, and molding resins.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising single carbon bridged metallocenes, which has a particular ligand system containing a heteroatom.

Abstract: A multi-stage process for preparing ethylene (co)polymers having broad molecular weight distributions is disclosed, said process comprising: (A) a first polymerization stage in which, in the presence of a Ti or V catalyst, a first ethylene polymer is prepared; (B) a treatment stage in which the catalyst used in the first stage is deactivated and in which a bridged bis-2-indenyl zirconocene is supported on the ethylene polymer produced in stage (A), optionally in the presence of a suitable cocatalyst; and (C) a second polymerization stage in which ethylene is polymerized in the presence of the product obtained from stage (B). Furthermore, polyethylene obtainable by the above process is disclosed, having intrinsic viscosity ranging from 0.5 to 6 dl/g, Mw/Mn>8 and cold xylene solubility<1.2 % wt.