Abstract: A prepolymerization catalyst for use in a gas phase polymerization of an olefin or combinations of olefins which comprises (A) a solid catalyst component comprising magnesium, halogen, titanium and an electron donor and having a weight-average particle diameter of 15 to 45 &mgr;m, (B) at least one organoaluminum compound and (C) a prepolymer of an ethylene and/or at least one &agr;-olefin, wherein the molar ratio of aluminum to titanium in the prepolymerization catalyst (Al/Ti ratio) is 3 to 11 (mol/mol), the weight ratio of the prepolymerization catalyst to the solid catalyst component (prepolymerization catalyst/solid catalyst component) is 2 to 35 (g/g), the content of volatile materials (VM) in the prepolymerization catalyst is 2.0% by weight or less, and the intrinsic viscosity [&eegr;] measured in tetralin at 135° C. is 2.0 dl/g or less, and a process for a production thereof.

Abstract: The present invention relates to a silica gel-supported catalyst component suitable for ethylene (co)polymerization, a catalyst therefrom and use of the same. The catalyst component according to the present invention is obtained by supporting the reaction product of a titanium compound, a halide promoter, a magnesium compound and an electron donor on silica gel having a larger specific surface area. When the resultant catalyst is used for ethylene polymerization, especially gas phase fluidized bed polymerization, not only the activity is substantially enhanced, but also the hydrogen response and the copolymerizability of ethylene with other alpha-olefins are improved. The catalyst is especially suitable for the fluidized bed polymerization operated in a condensed state, with high quality LLDPE resins being obtained.

Abstract: The present invention provides polypropylene having xylene solubles from 0.6 to 1.5 weight percent and isotacticity equal to or greater than about 98.0 percent. The polypropylene is obtained by contacting propylene monomer under suitable polymerization conditions with (a) a Ziegler-Natta catalyst, (b) a co-catalyst, and (c) an electron donor.

Abstract: There are provided;

Abstract: A process for polymerizing propylene is disclosed. The process involves charging propylene and about 90 to 99% of an organoaluminum cocatalyst to a reactor and heating this mixture to at least about 50° C. This is followed by addition of a premix of 1 to 10% of the organoaluminum cocatalyst with a magnesium halide-supported Ziegler-Natta catalyst. The temperature of the reaction mixture is maintained to produce a propylene polymer. The process gives improved catalyst activity.

Abstract: Catalyst solid for olefin polymerization comprising

Abstract: A catalyst having high activity independent of the hydrogen concentration and low gel productivity in the polymerization of ethylene has been prepared.

Abstract: There are provided:

Abstract: Method of preparation of ethylene copolymers suitable for manufacturing films or pipes so characterized that for the initiation of polymerization of ethylene and 1-alkene monomer a substantially innovated catalyst system containing silyl chromate compound is used. The catalyst system, containing a high yield structure A, is prepared by a sequential interaction of the following components: a) a silyl chromate compound completely freed from water and oxygen prior to its contact with the porous support, b) a support containing a suitable type and optimum concentration of hydroxyl groups, and c) an alkylating agent, being a combination of organometal compounds of aluminum (RO)AlR2 and magnesium (R1MgR2), the ratios between the components in the catalyst vary in the following ranges: content of silyl chromate on the support varies from 0.05 to 0.35% of the support weight, ratio between the total amount of organometals (ORG) to silyl chromate (expressed in terms of ORG/Cr) varies between 0.

Abstract: There are disclosed a process for producing a solid catalyst component and a catalyst for &agr;-olefin polymerization, and a process for producing an &agr;-olefin polymer, wherein the process for producing a solid catalyst component comprises the steps of: (1) reducing a specific titanium compound with an organomagnesium compound in the presence of an organosilicon compound having an Si—O bond (and an ester compound), thereby obtaining a solid product, and (2) contacting the solid product with at least one member selected from the group consisting of an electron donor compound (E1) and an organic acid halide, and a compound having a Ti-halogen bond, thereby obtaining the solid catalyst component.

Abstract: Provided is a catalyst system for polymerization of monomer having at least one Ziegler-Natta polymerizable bond comprising: c) a supported Ziegler-Natta transition metal catalyst component comprising a Group 15 atom having two groups selected from the group consisting of alkyl and aryl, wherein the support is a magnesium halo dialkylamide; and d) an effective co-catalyst.

Abstract: Process for the polymerization of olefins, according to which at least one olefin is placed in contact with a catalytic system comprising: a) a solid catalytic complex based on magnesium, transition metal and halogen, the said catalytic complex being prepared by reacting, in a first step, at least one magnesium compound with at least one compound of a transition metal from group IVB or VB of the Periodic Table, until a liquid complex is obtained, and, in a subsequent step, by precipitating the said liquid complex using a halogen-containing organoaluminium compound of general formula AlRnX3-n in which R is a hydrocarbon radical, X is a halogen and n is less than 3, in order to collect a solid catalytic complex, and b) an organometallic compound of a metal from groups IA, IIA, IIB, IIIA and IVA of the Periodic Table, c) at least one electron donor used after the first step in the preparation of the solid catalytic complex leading to the production of a liquid complex.

Abstract: Solid catalyst component for the polymerization of olefins, includes the product of the direct reaction, with no subsequent reactions with reducing organometallic compounds, between a titanium compound and a support obtained by contacting a metal oxide containing hydroxyl groups with a solution containing A) a magnesium chloride; B) from 1 to 6 moles of an alcohol per mole of magnesium chloride, in a halogenated hydrocarbon or aromatic hydrocarbon organic solvent C) capable of bringing the magnesium chloride in solution in quantities greater than or equal to 5 grams per liter in the presence of the above-mentioned quantities of alcohol B), the solvent not being able to form adducts with the magnesium chloride.

Abstract: There are provided: (I) a solid catalyst component (A-1) for olefin polymerization, which is obtained by a process comprising the step of contacting: (a-1) a carrier of carboxyl group-carrying polymer particles having an average particle diameter of from 1 to 300 &mgr;m, and (b) a transition metal compound of the number 4 group of metals in the periodic table of elements; (II) a catalyst for olefin polymerization, which is obtained by a process comprising the step of contacting: (A-1) the above solid catalyst component, and (B) at least one compound selected from the group consisting of an organoaluminum compound and an organoaluminumoxy compound; (III) a process for producing an olefin polymer, which comprises the step of polymerizing an olefin in the presence of the above catalyst; and (IV) a process for producing the above solid catalyst component (A-1), which comprises the step of contacting: (a-1) the above carrier, and (b) the above transition metal compound.

Abstract: The present invention relates to a highly active titanium based supported catalyst suitable for olefin (co)polymerization, preparation and use of the same. The catalyst according to the present invention is obtained by supporting a titanium based catalyst component containing a halide promoter on spherical silica. The resultant catalyst is excellent in its particle morphology and flowability, has highly catalytic activity, has excellent hydrogen response and has superior comonomer incorporation, the polymer prepared by using such a catalyst has its particle morphology further improved.

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: Components of catalysts for the polymerization of olefins are obtained by contacting a Ti compound of formula Ti(OR)n−yXy, where n is the valence of titanium and y is a number between 1 and n, with a pre-polymer having a porosity higher than 0.3 cc/g and containing from 0.5 to 100 g of polymer per g of solid catalyst component, the pre-polymer being obtained by (co)polymerizing an olefin or a diolefin in the presence of a catalyst comprising a Ti, V, Zr of Hf compound supported on an Mg dihalide having a mean crystallite dimension lower than 30 nm.

Abstract: A process of enhancing both the activity and the methane selectivity of a particulate Dispersed Active Metal (“DAM”) hydrogenation catalyst is disclosed wherein the DAM undergoes low temperature oxidation in a slurry phase to form a stable, unique oxidized catalyst precursor that is subsequently reduced to form an enhanced catalyst by treatment with hydrogen-containing gas at elevated temperature, wherein one or more promoter metal oxides of chromium, lanthanum and manganese are added to the DAM. Precursors of the promoter metal oxides may be combined with the DAMs prior to or during formation of the initial slurry, during the oxidation step or between recovery of the oxidized catalyst precursor and treatment of it with hydrogen-containing gas to reactivate the catalyst. Conversion of the precursors to the promoter metal oxides is carried out prior to the treatment with hydrogen-containing gas unless said treatment itself produces the conversion.

Abstract: Catalyst components for the preparation of ethylene (co)polymers capable to produce polymers with high bulk density, to avoid the problems of formation of fines and that have a high activity are provided. Said catalyst components are characterized by comprising a non-stereospecific solid catalyst component, comprising a titanium compound and a magnesium dihalide, which is pre-polymerized with an alpha olefin CH2═CHR1 wherein R is a C1-C8 alkyl group, to such an extent that the amount of the &agr;-olefin pre-polymer is up to 100 g per g of said solid catalyst component.

Abstract: This invention provides a solid titanium catalyst component which comprises magnesium, titanium, halogen and an electron donor, is free from elimination of titanium when washed with hexane at room temperature, and has a titanium content decrease ratio of less than 15 % by weight when washed with o-dichlorobenzene at 90° C. The catalyst component can be prepared by a process wherein solid titanium (i) which is free from elimination of titanium when washed with hexane at room temperature is contacted with a polar compound having a dipole moment of 0.50 to 4.00 Debye to decrease the titanium content by at least 25 % by weight, whereby a solid titanium catalyst component having a weight ratio of an electron donor to titanium of at least 6 is prepared. Olefin polymerization catalyst containing the solid titanium catalyst component can be used for (co)polymerization of olefins with high activity to obtain a polyolefin of high stereoregularity in decreased quantities of a low stereoregular polyolefin.

Abstract: A process of forming a bimetallic catalyst composition comprising a cocatalyst (a trialkylaluminum compound) and a catalyst precursor. The precursor comprises at least two transition metals; a metallocene complex is a source of one of said two transition metals. The precursor is produced in a single-pot process by contacting a porous carrier, in sequence, with a dialkylmagnesium compound, an aliphatic alcohol, a non-metallocene transition metal compound, a contact product of a metallocene complex and a trialkyl-aluminum compound, and methylalumoxane.

Abstract: The invention provides a process for producing polypropylene and/or random copolymers of propylene type using a stereoregular catalyst which comprises a titanium-containing solid catalyst component (A), an organoaluminum compound (B) and if required an organosilicon compound (C), wherein [I] before carrying out homopolymerization of propylene or random copolymerization of propylene with an &agr;-olefin other than propylene, the above component (A), an organoaluminum compound (B′) and if required an organosilicon compound (C′) are used, and a small amount of propylene or ethylene and/or an &agr;-olefin of 4-20 carbon atoms for pre-activation treatment is supplied to the above component (A), and [II] a catalyst which is prepared by adding an organosilicon compound (C″) to the pre-activated stereoregular catalyst in a molar ratio of 0.1-50 as Si/Ti, is used to produce polypropylene or propylene random copolymers.

Abstract: A method of halogenating a precursor to form a polymerization procatalyst is disclosed whereby a magnesium/transition metal-containing alkoxide complex precursor is contacted with a halogenating agent selected from alkylaluminum halide, TiX4, SiX4, BX3, and Br2, where halide and X are reach respectively a halogen, and when an alkylaluminum halide, TiX4, SiX4, BX3, and Br2 are used as the halogenating agent, they are used together or in combination in a multi-step halogenation. The procatalyst then can be converted to an olefin polymerization catalyst by contacting it with a cocatalyst and optionally a selectivity control agent, and used to polymerize olefins in high yield with desired properties.

Abstract: The invention relates to a process for uniformly dispersing a transition metal metallocene complex on a carrier comprising (1) providing silica which is porous and has a particle size of 1 to 250 microns, having pores which have an average diameter of 50 to 500 Angstroms and having a pore volume of 0.5 to 5.0 cc/g; (2) slurrying the silica in an aliphatic solvent having a boiling point less than 110° C.; (3) providing a volume of a solution comprising metallocene and alumoxane wherein the volume of solution is less than that required to form a slurry of the silica, wherein the concentration of alumoxane, expressed as Al weight percent, is 5 to 20; (4) contacting the silica slurry (2) with said volume of said solution (3) and allowing the solution to impregnate the pores of silica and, to disperse the metallocene in and on the carrier; (5) evaporating the solvents from the contacted and impregnated silica to recover dry free-flowing catalyst particles.

Abstract: A Ziegler-Natta type catalyst having an improved hydrogen response provides for narrowing of the MWD of resulting polyolefins polymerized using such catalyst, with such catalyst generally made by a) contacting a soluble magnesium dialkoxide compound of the general formula Mg(OR″)2 with a halogenating agent capable of exchanging one halogen for one alkoxide to form a reaction product A, where R″ is a hydrocarbyl or substituted hydrocarbyl having from 1 to 20 carbon atoms; b) contacting reaction product A with a first halogenating/titanating agent to form reaction product B; and c) contacting reaction product B with a second halogenating/titanating agent to form a catalyst component; wherein in at least one of steps b) and c), the halogenating/titanating agent is a blend of Ti(OPr)4 and TiCl4. Catalyst components, catalysts, catalyst systems, polyolefin polymers, and methods of forming each are disclosed.

Abstract: A method for producing a supported catalyst useful in polymerization of ethylene and copolymerization of ethylene and &agr;-olefin is disclosed. The method includes treating the magnesium-containing carrier with a titanium compound containing oxygen atom(s), wherein said carrier is obtained by reaction of an organomagnesium compound of the structure of MgPh2.nMgCl2.mR2O (n=0.37˜0.7; m≧1; R20=ether; Ph=phenyl) with an organic chloride compound in a mole ratio of organic chloride compound/Mg≧0.5, at −20˜80° C. In one embodiment, the organic chloride compound may be carbon tetrachloride. A specific catalyst is provided whose activity is low in the beginning but slowly rises to a sufficient degree as the process of polymerization progresses, the polymer produced with the use of said catalyst having high bulk density, a well adjusted particle size distribution, and a narrow molecular weight distribution.

Abstract: The invention provides new prepolymerized catalyst components for the (co)polymerization of olefins CH2═CHR, wherein R is hydrogen or a C1-C12 alkyl group, characterized by comprising a solid catalyst component, comprising Ti, Mg, halogen and an electron donor compound, being capable of yielding, under standard polymerization conditions, a propylene homopolymer having an insolubility in xylene at 25° C. higher than 90%, which is prepolymerized with ethylene to such an extent that the amount of the ethylene prepolymer is up to 100 g per g of said solid catalyst component. These solid catalyst components display to obtain a high catalyst activity, a high isotactic index, and are not affected by aging.

Abstract: A supported catalyst system suitable for the polymerization of olefins prepared by a specific preparative route comprising optionally pretreating a support followed by addition of a neutral metal complex/activator solution. The metal complex may be a metallocene in particular a complex with trifluoromethanesulfonate ligands and the activator is a Lewis acid.

Abstract: Components of catalysts for the polymerization of olefins are obtained by contacting a Ti compound of formula Ti(OR)n−yXy, where n is the valence of titanium and y is a number between 1 and n, with a pre-polymer having a porosity higher than 0.3 cc/g and containing from 0.5 to 100 g of polymer per g of solid catalyst component, the pre-polymer being obtained by (co)polymerizing an olefin or a diolefin in the presence of a catalyst comprising a Ti, V, Zr of Hf compound supported on an Mg dihalide having a mean crystallite dimension lower than 30 nm.

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: Catalysts that have been preactivated and/or prepolymerized are disclosed whereby a magnesium and titanium-containing procatalyst component is contacted with a co-catalyst and an external electron donor (and optionally with an olefin monomer to prepare a prepolymerized catalyst) prior to polymerization to form a preactivated and/or prepolymerized catalyst. The preactivated and/or prepolymerized catalyst then is separated from the mixture, and dried to form a solid preactivated and/or prepolymerized catalyst. This dried catalyst then can be stored and subsequently shipped to a polymerization site where it can be used in gas phase polymerization. The preactivated and/or prepolymerized catalyst can be used in gas phase polymerization as extremely high activity catalysts, and do not cause a rapid rise in reaction temperature causing overheating, undesirable formation of agglomerates, coagulation of polymer, and ultimately, reactor failure.

Abstract: There has been invented a codeposition process for fabricating hydrogen scavengers. First, a &pgr;-bonded allylic organometallic complex is prepared by reacting an allylic transition metal halide with an organic ligand complexed with an alkali metal; and then, in a second step, a vapor of the &pgr;-bonded allylic organometallic complex is combined with the vapor of an acetylenic compound, irradiated with UV light, and codeposited on a substrate.

Abstract: A novel supported catalyst component useful for &agr;-olefin polymerization and a method of polymerizing an &agr;-olefin using the same. The catalyst component is characterized by being prepared by contacting a complex represented by general formula (I) wherein R1 and R2 are the same or different and each represents a C1-6 linear or branched alkyl, a C1-3 haloalkyl, or optionally substituted phenyl; and X represents a halogeno with magnesium compound.

Abstract: A catalyst composition for the polymerization of one or more 1-olefins (e.g., ethylene) comprises a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising a contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution. In another embodiment, the transition metal catalyst precursor is bimetallic and contains a non-metallocene transition metal catalyst component. When a bimetallic catalyst precursor is used, the resin product exhibits improved properties, and has a bimodal molecular weight distribution, long chain branching (LCB), and good bubble stability.

Abstract: A process of forming a bimetallic catalyst composition comprising a cocatalyst (a trialkylaluminum compound) and a catalyst precursor. The precursor comprises at least two transition metals; a metallocene complex is a source of one of said two transition metals. The precursor is produced in a single-pot process by contacting a porous carrier, in sequence, with a dialkylmagnesium compound, an aliphatic alcohol, a non-metallocene transition metal compound, a contact product of a metallocene complex and a trialkylaluminum compound, and methylalumoxane.

Abstract: A catalyst composition for polymerization of olefins comprising: (ia) a catalyst precursor corresponding to the formula: MgdTi(ORe)eXf(ED)g, wherein Re is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms or COR′ wherein R′ is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbons atoms; X is halide; ED is an organic Lewis base electron donor; d is 0.5 to 56; e is 0, 1, or 2; f is 2 to 116; and g is 1.5d+2 (ib) an aluminum trialkyl or aluminum alkyl halide cocatalyst compound; and (ii) a lanthanide compound represented by the following formula: CpaLnRbbLc wherein Cp is a cyclopentadienyl or substituted cyclopentadienyl ligand; Ln is a lanthanide metal; Rb is a hydride, alkyl, silyl, halide, or aryl group; L is an electron donor; a+b is the valence of the lanthanide metal; and c is a number from 1 to 8.

Abstract: A make-up catalyst of at least one metallic component of a bimetallic catalyst component is used in conjunction with a bimetallic catalyst to control the proportion of weight fractions in broad or bimodal molecular weight distribution olefin resin product. The bimetallic catalyst which is formed with at least one metallocene of a transition metal, produces broad or bimodal molecular weight distribution polyolefin resin whose composition depends on the ratio of the concentration of the two catalyst components producing the HMW/LMW components. The make-up catalyst consisting of a single metal component is added in proportion necessary to make-up the deficiencies in the amount of the HMW/LMW component. The type of make-up catalyst added depends on whether increase of the HMW or LMW component produced by the bimetallic catalyst is sought.

Abstract: The present invention provides a catalyst system that exhibits unexpected control of desired properties in copolymer product. The catalyst system includes a conventional supported Ziegler-Natta catalyst in combination with an electron donor described by the formula: wherein R1 is a linear alkyl group attached to the silicon atom; R2 and R3 are alkyl or aryl groups and R4 is a linear alkyl attached to the silicon atom, R1 and R4 are the same or different. R1 and R4 are preferably linear carbon groups of 4-13 carbon atoms, more preferably 4-7 carbon atoms; most preferably R1 and R4 are the same and are n-butyl groups. The system exhibits good control over the melt flow index of the copolymer products.

Abstract: Catalyst composition for use in the polymerization of olefins comprise neutral metal complexes together with activators comprising non-aromatic boron compounds. Suitable activators are triisobutylboron together with trialkylaluminium compounds. Preferred complexes are metallocenes. The use of such activating systems obviates the need for expensive aluminoxanes or aromatic fluorine containing compounds.

Abstract: A novel supported catalyst component useful for &agr;-olefin polymerization and a method of polymerizing an &agr;-olefin using the same. The catalyst component is characterized by being prepared by contacting a complex represented by general formula (I) wherein R1 and R2 are the same or different and each represents a C1-6 linear or branched alkyl, a C1-3 haloalkyl, or optionally substituted phenyl; and X represents a halogeno with magnesium compound.

Abstract: The present invention relates to a process to produce polyethylene through homopolymerization or copolymerization of ethylene with alpha-olefins in the presence of a titanium amide catalyst supported by an organic polymer material, for the production of moldings, such as through extrusion, injection molding, film blowing, sintering under pressure or ram extrusion. The catalyst according to the present invention contains a partially chloromethylated styrene divinyl benzene copolymer as the organic polymer material, a complex compound supported by it, which contains Mg, Al and Ti.

Abstract: The present invention provides a method of making a catalyst with the following components: Component (A): A solid catalyst component comprising the following component (A-1) and component (A-2). Component (A-1): A solid component obtained by contacting the following component (A-1-1), component (A-1-2) and component (A-1-3).

Abstract: A method is presented for increasing molecular weight and/or stereoregularity of poly(alpha-olefins) by polymerizing alpha-olefins in the presence of 1) a Ziegler-Natta catalyst system and 2) at least one non-polymerizing olefin which is not polymerizable under the polymerization conditions.

Abstract: Described are a MgCl2 based carrier containing Ti(OR)4 and ROH, wherein R is C1˜C7alkyl, and solid catalyst components made from said carrier. The carrier and the solid catalyst components according to the present invention are characterized in that in their X-rays powder diffraction spectra, one or two main diffraction lines or a halo appears at 2&thgr; of 2˜14° and in the range of 2&thgr; of 14˜50°, there are the characteristic diffraction lines of anhydrous &agr;-MgCl2. The carrier according to the present invention is directly obtained by reacting anhydrous magnesium chloride with an alcohol and can be used to prepare solid catalyst components without dealcoholization, and the solid catalyst components exhibit high polymerization activity when employed for polymerizing ethylene.

Abstract: Disclosed is a high activity solid catalyst for synthesizing low-, medium- and high-density polyethylenes by a slurry phase process, prepared by using commercial powered magnesium as raw material, forming a magnesium halide in the nascent state, followed by successively treating said magnesium halide with an alcohol compound and an alkyl aluminum compound, then reacting the resulting suspension of the spheroidal, porous solid complex carrier with a titanium compound in the presence of an electron donor compound an alkyl aluminum compound to obtain a main catalyst component and finally mixing the catalyst component with an organometallic compound as cocatalyst.

Abstract: A method is presented for increasing molecular weight and/or stereoregularity of poly(alpha-olefins) by polymerizing alpha-olefins in the presence of 1) a Ziegler-Natta catalyst system and 2) at least one non-polymerizing olefin which is not polymerizable under the polymerization conditions.

Abstract: Disclosed is a catalyst for synthesizing low-, medium- and high-density polyethylene, prepared by using commercial powdered magnesium as a raw material, forming a magnesium halide in the nascent state, then reacting said magnesium halide with a titanium compound and an alkyl aluminum compound in the presence of an electron donor compound to form a complex, supporting said complex onto silica carrier and drying the resulting mixture by heating to form a solid main catalyst component, and finally mixing said main catalyst component with an organometallic compound as cocatalyst. The catalyst according to the present invention is characterized by a simple preparing procedure, smooth and stable reaction, uniform heat liberation and less agglomerates when used for gas phase polymerizing ethylene, high polymerization activity, high sensitivity to the modification by hydrogen and high copolymerization power, and the products thus obtained have good product morphology.

Abstract: A catalyst component, adapted for use in the polymerization and copolymerization of ethylene, is formed by reaction of an organomagnesium compound with a metal oxide support to form a supported organomagnesium composition, reaction of the supported organomagnesium composition and a tetraalkyl silicate, contact of the resulting product with a chlorinating reagent, and treatment of the product from the previous step with liquid titanium halide.

Abstract: A composition comprising (i) a supported or unsupported magnesium/titanium based catalyst precursor including an electron donor and (ii) a lanthanide catalyst precursor represented by the following formula: CpaLnRbbLc wherein Cp is a cyclopentadienyl or substituted cyclopentadienyl ligand; Ln is a lanthanide metal; Rb is a hydride, alkyl, silyl, halide, or aryl group; L is an electron donor; a+b is the valence of the lanthanide metal; and c is a sufficient amount of electron donor to stabilize the lanthanide metal.

Abstract: The present invention provides cocatalysts for activating metallocene complexes in olefin polymerization reactions, and metallocene catalyst systems using the cocatalysts. The cocatalysts of the present invention include: (a) a halo-organoaluminum compound of the formula AlnRmX3n-m, where Al is aluminum, each R is independently a Cl to C4 alkyl group, X is a halide, n is 1 or 2, and m is determined by the valency of Al; and (b) a dialkylmagnesium compound of the formula MgR′2, where Mg is magnesium and R′ is a C2 to C6 alkyl group. The components (a) and (b) are used in amounts such that the molar ratio of Al:Mg is at least 2, preferably from 2:1 to 5:1.