Abstract: A metallocene catalyst may be temporarily and reversibly passivated by contact with an effective amount of a passivating compound selected from the group of oxygen, oxygen-containing compounds, and nitrogen-containing compounds.

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: Described are catalyst systems having aluminium alkyl complexes of the formula (I) described herein applied to magnesium chloride, SiO2 or SiO2 in combination with MgCl2 as support in the presence of titanium halides or vanadium halides and internal and, if desired, external donors act both as cocatalysts and as stereoselectivity promoters in heterogeneous polymerizations of &agr;-olefins. Also described are polymerization methods using these catalyst systems.

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: There are disclosed: (1) a process for producing a catalyst for olefin polymerization, which comprises the step of contacting with one another: (i) a solid catalyst component containing at least titanium, magnesium and halogen atoms, (ii) an organoaluminum compound, and (iii) a compound selected from the group consisting of (a) an oxygen-containing compound having a structure wherein at least two hydrocarbyloxy groups are bound to the same carbon atom, and (b) a cyclic ketone compound, and (2) a process for producing an olefin polymer, which comprises the step of polymerizing an olefin in the presence of the above-mentioned catalyst.

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 solid titanium complex catalyst for polymerization and copolymerization of ethylene is prepared by the process comprising: (1) preparing a magnesium solution by reacting a halogenated magnesium compound with an alcohol; (2) reacting the magnesium solution with an ester compound having at least one hydroxyl group and a silicon compound having an alkoxy group to produce a magnesium composition; and (3) producing a solid titanium catalyst through recrystallization by reacting the magnesium composition solution with a mixture of a titanium compound and a haloalkane compound; and optionally reacting the solid titanium catalyst with an additional titanium compound. The solid titanium complex catalyst for polymerization and copolymerization of ethylene according to present invention exhibits high catalytic activity, high hydrogen reactivity and controlled particle size, and can advantageously used in the polymerization and copolymerization of ethylene to produce polymers of high bulk density.

Abstract: The present invention relates to catalyst components for the polymerization of olefins comprising a titanium compound, having at least a Ti-halogen bond, and at least two electron donor compounds supported on a Mg dihalide, said catalyst component being characterized by the fact that at least one of the electron donor compounds is selected from ethers containing two or more ether groups which are further characterized by the formation of complexes with anhydrous magnesium dichloride in an amount less than 60 mmoles per 100 g of MgCl2 and by the failure of entering into substitution reactions with TiCl4 or by reacting in that way for less than 50% by moles, and at least another electron donor compound is selected from esters of mono or polycarboxylic acids. Said catalyst components are able to produce propylene polymers which, for high values of xylene insolubility, show a broad range of isotacticity.

Abstract: Catalyst-forming components and catalysts for the polymerization of olefins based on said components are disclosed. The catalysts comprise the reaction product of: (a) an Al alkyl compound; (b) a silicon compound containing at least a Si—OR or Si—OCOR or Si—NR2 bond, R being a hydrocarbyl radical; and (c) a solid comprising, as essential support, a Mg dihalide in active form and, supported thereon, a Ti halide or a halo-Ti-alcoholate or said halogenated Ti compound and a silicon compound as defined in (b) in a molar ratio with the supported Ti compound from 1.0 mole to 5 moles of silicon compound per mole of Ti compound. The present invention refers to new supported components of catalysts for the polymerization of CH2═CHR olefins wherein R is an alkyl radical with 1 to 4 carbon atoms, or an aryl radical, and mixtures of said olefins with ethylene, and to the catalysts obtained from said components.

Abstract: A polypropylene catalyst (no more than 2 wt % titanium) contains at least one titanium-halogen bond-containing compound, internal donor, and activated, amorphous magnesium dihalide support, essentially free of alkoxy functionality.

Abstract: The invention is directed to a process for the preparation of a catalyst component for the polymerization of an olefin by:

Abstract: A lower &agr;-alkene polymerisation heterogeneous solid catalyst which comprises a hydrated magnesium chloride derived procatalyst, a cocatalyst comprising an organoaluminium compound and a selectivity control agent comprising an ester or ether. The procatalyst comprises a titanium tetrahalide supported on a magnesium chloride ester complex precursor. The internal electron donor ester component of the precursor is generated insitu by reaction of a magnesium chloride alcoholate with an activated carbonyl compound in the mole ratio 0.5-1:10-20. The magnesium chloride alcoholate is formed of hydrated magnesium chloride and an aliphatic alcohol in the mole ratio of 0.5-1:10-20. The mole ratio of the aluminium to the titanium is 10-300:1 and that of the selectivity control agent to titanium is 10-100:1. The process for the preparation of the catalyst comprises mixing a hydrated magnesium chloride derived procatalyst, a cocatalyst and a selectivity control agent.

Abstract: The present invention relates to an initiation system composed of the reaction product of at least one cyclic siloxane and at least one organometalic compound of sufficient reactivity to open the siloxane ring. Application of the present invention is to the preparation of homopolymers of (meth)acrylic, vinylaromatic or diene monomers, random or block copolymers of these monomers and, in particular, application to poly(methylmethacrylate) with a high content of isotactic triads.

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 process for the production of a magnesium chloride powder for use in a catalyst, the process comprising vaporising magnesium chloride in a plasma torch and quenching the vapour with a liquid containing an electron donor to form a magnesium chloride-based powder catalyst wherein at least 80% by weight of the magnesium chloride is present as the hexagonal phase thereof. The invention also relates to a precursor for such a catalyst.

Abstract: The invention relates to a catalyst support and to a method for the production of the catalyst support comprising the following steps:

Abstract: This invention relates to a process for preparation of high 1,4-cis polybutadiene and more particularly, to the process for preparing polybutadiene by polymerizing 1,3-butadiene monomer in the presence of a catalyst prepared by aging a mixture of a neodymium salt compound, a nickel salt compound, an organoaluminium compound and a borontrifluoride complex compound in the presence or absence of a conjugated diene compound. With much remarked catalytic activity, polybutadiene with a very high 1,4-cis content can be prepared in a high yield using a small amount of catalyst.

Abstract: There are provided (1) a process for producing a solid product, which comprises the step of reducing a titanium compound represented by the following formula [I] with an organomagnesium compound in the presence of an organosilicon compound having an Si—O bond, an inorganic fine particle and optionally an ester compound, 1

Abstract: The invention relates to a catalyst component which can provide, in combination with a transition metal compound, a catalyst for ethylenically unsaturated monomer polymerization, a catalyst comprising the catalyst component and a transition metal compound, and a process for ethylenically unsaturated monomer polymerization using the catalyst. The catalyst component comprises a compound obtained by the reaction of, in any order, (i) a compound comprising a metal of Group 13 of the periodic table; (ii) a compound capable of reacting with the compound (i) to be bonded to two or more of the Group 13 metal; (iii) a compound capable of reacting the compound (i); and optionally (iv) a hydrocarbon compound or the like.

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: 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: Unsaturated nitrogenous compounds are used as electron donors in conjunction with catalytic polymerization of addition polymerizable monomers such as olefins, using supported Ziegler-Natta catalysts. The electron donors may be used in the preparation of catalyst systems, thus serving as “internal” electron donors, or they may be added during or just prior to polymerization, as an “external” electron donor.

Abstract: The present invention relates to MgCl2.mROH.nH2O adducts, where R is a C1-C10 alkyl, 2≦m≦4.2, 0≦n≦0.7 , characterized by an X-ray diffraction spectrum in which, in the range of 2&thgr; diffraction angles between 5° and 15°, the three main diffraction lines are present at diffraction angles 2&thgr; of 8.8±0.2°, 9.4±0.2° and 9.8±0.2°, the most intense diffraction lines being the one at 2&thgr;=8.8±0.2°, the intensity of the other two diffraction lines being at least 0.2 times the intensity of the most intense diffraction line. Catalyst components obtained from the adducts of the present invention are capable to give catalysts for the polymerization of olefins characterized by enhanced activity and stereospecificity.

Abstract: A catalyst composition has a catalyst component which includes a metallocene transition metal compound, a magnesium compound, a hydroxyl containing compound, and a polymeric material. The catalyst component may also include asilicon compound and an aluminum compound. The catalyst component is combined with a cocatalyst and used in olefin polymerization.

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: Catalyst systems of the Ziegler-Natta type, which are suitable for the polymerization of olefins are prepared by:

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: The invention relates to a novel process for the preparation of an olefin polymerization catalyst component comprising magnesium, titanium, a halogen and an electron donor.

Abstract: Disclosed is a solid titanium catalyst component which is obtained by a process comprising the steps of bringing (a) a liquid magnesium compound into contact with (b) a liquid titanium compound in the presence of (c) an organosilicon compound having no active hydrogen in an amount of 0.25 to 0.35 mol based on 1 mol of the magnesium compound (a), elevating the temperature of the resulting contact product to a temperature of 105 to 115° C. and maintaining the contact product at this temperature. The contact product may be further brought into contact with not more than 0.5 mol of the organosilicon compound having no active hydrogen (c). Also disclosed are an ethylene polymerization catalyst formed from the solid titanium catalyst component and an organometallic compound and an ethylene polymerization process using the catalyst. By the use of the solid titanium catalyst component, ethylene can be polymerized with high activities and an ethylene polymer having excellent particle properties can be prepared.

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: The present invention relates to components of catalysts for the polymerization of olefins comprising a metallocene compound and a magnesium halide which have particular values of porosity and surface area. Group 4 and vanadium metallocenes are useful metallocenes and the components typically include an electron donor such as an ether, ester or ketone. In particular the components of the invention have surface area (BET) greater than about 50 m2/g, porosity (BET) greater than about 0.15 cm3/g and porosity (Hg) greater than 0.3 cm3/g, with the proviso that when the surface area is less than about 150 m2g, the porosity (Hg) is less than about 1.5 cm3/g. The magnesium halide is complexed by an ether, ester, or ketone electro donor. The components of the invention are particularly suitable for the preparation of catalysts for the gas-phase polymerization of &agr;-olefins.

Abstract: The present invention relates to catalyst components for the polymerization of olefins having Mg, Ti, halogen and at least two internal electron donor compounds, said catalyst components characterized by the fact that at least one of the electron donor compounds is selected from ethers containing two or more ether groups which are further characterized by the formation of complexes with anhydrous magnesium dichloride in an amount less than 60 mmoles per 100 g of MgCl2 and by the failure of entering into substitution reactions with TiCl4 or by reacting in that way for less than 50% by moles, and at least another electron donor compound selected from esters of mono or polycarboxylic acids. Said catalyst components are able to produce propylene polymers which, for high values of xylene insolubility, show a broad range of isotacticity.

Abstract: The present invention relates to a solid catalyst component for &agr;-olefin polymerization having a narrow particle size distribution of not less than 6.0 in terms of the value of N in a Rosin-Rammler function of particle size distribution and giving a catalytic activity of not less than 10,000 ((g-polymer produced/g-solid catalyst component)/hour) in polymerization. According to the present invention, there can be provided a solid catalyst component for &agr;-olefin polymerization capable of giving a poly-&agr;-olefin having the high bulk density and favorable particle properties with high catalytic activity.

Abstract: A catalyst component formed by the steps of contacting a transition metal-containing metallocene of a transition metal of Group 4, 5 or 6 of the Periodic Table of the Elements with silica or an organic support. This product is contacted with an organomagnesium compound or complex followed by contact with an alcohol and a silane. Finally, the so-contacted product is contacted with a Group 4, 5 or. 6 transition metal-containing non-metallocene compound. The component is preferably combined with an aluminum-containing cocatalyst to form a catalyst system.

Abstract: The invention relates to high-activity catalysts for olefin polymerization, to efficient methods for producing them, and to efficient methods of using the catalysts for producing high-quality polyolefins. The olefin polymerization with the catalysts does not require a large amount of an organic aluminium compound, and the residual metal in the polyolefins produced is much reduced. The catalysts are characterized by containing a product as prepared by contacting any of clay, a clay mineral and an ion-exchanging layered compound, an organic silane compound, and water with each other, or by containing a silane compound-processed clay.

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: A catalyst for the polymerization of propylene comprising components (A), (B) and (C) is provided. Component (A) is a solid product prepared by dissolving a halide of magnesium in a solvent system consisting of an organic epoxy compound, an organic phosphorus compound and an inert diluent to form a homogeneous solution; mixing the homogeneous solution with a halide of titanium to form a mixture; precipitating a solid from the mixture in the presence of an auxiliary precipitant; treating the solid with a polycarboxylic ester to load the ester on the solid; and treating the ester loaded solid with the halide of titanium and the inert diluent. Component (B) is an organic aluminium compound, and component (C) is an organic silicon compound. The particle size of the catalyst can be adjusted by increasing the amount of the inert diluent at a low ratio of the epoxy compound to the phosphorus compound.

Abstract: The present invention relates to a method for producing a polymer and copolymer of ethylene, and more particularly to a method for producing an ethylene polymer and copolymer by reacting a compound of an organic metal of Group II or m on the periodic table of elements with an alkoxy silane compound in the presence of a titanium catalyst, the said titanium catalyst being produced by a process of preparing a magnesium compound by contact-reacting a halogenated magnesium compound and alcohol, of reacting the said solution with an ester compound which contains at least one hydroxy group and a silicon compound containing an alkoxy group, and also of reacting it with a solid matter obtained by reaction of a mixture of a titanium compound and a silicon compound with a titanium compound.

Abstract: A catalyst used for trimerization of ethylene into 1-hexene is descrobed, which comprises (i) a specific organometallic complex having a neutral multidentate ligand having a tripod structure, (ii) an alkylaluminoxane, and an optional ingredient selected from:

Abstract: One aspect of the present invention relates to a catalyst system for use in olefinic polymerization, containing a solid titanium catalyst component; an organoaluminum compound having at least one aluminum-carbon bond; and an organosilicon compound comprising a (cycloalkyl)methyl group. Another aspect of the present invention relates to a method of making a catalyst for use in olefinic polymerization, involving the steps of reacting a Grignard reagent having a (cycloalkyl)methyl group with an orthosilicate to provide an organosilicon compound having a (cycloalkyl)methyl moiety; and combining the organosilicon compound with an organoaluminum compound having at least one aluminum-carbon bond and a solid titanium catalyst component to form the catalyst.

Abstract: A mixed metal-containing precursor is disclosed whereby the precursor includes: a) MgZrMx where M is selected from one or more metals having a +3 or +4 oxidation state, x is from 0 to about 2, and where the molar ratio of magnesium to the mixture of zirconium and M is within the range of from about 2.5 to 3.6; and b) at least one moiety complexed with component a) selected from the group consisting of alkoxide groups, phenoxide groups, halides, hydroxy groups, carboxylate groups, amide groups, and mixtures thereof A polymerization procatalyst prepared from the mixed metal containing precursor, methods of making the precursor and procatalyst, as well as polymerization methods using the procatalyst also are disclosed.

Abstract: A process for preparing polyolefins by polymerizing or coploymerizing an olefin or olefins in the presence of a catalyst comprising a solid catalyst component and an organometallic compound is provided.

Abstract: A process for preparing premixed supported boraaryl catalysts having improved shelf life is provided. The process comprises supporting an organometallic compound comprising a group 3-10 transition metal or lanthanide metal and at least one boraaryl ligand an inorganic support which has been chemically and thermally dehydroxylated to remove all hydroxyl from the surface of the support; contacting with an organoaluminum compound utilizing an incipient wetness procedure wherein 90 to 150 percent of the catalyst pore volume is filled with a hydrocarbon solution containing the organoaluminum and provide a molar ratio of aluminum to transition/lanthanide metal of 0.5:1 to 50:1; and recovering the premixed catalyst powder.

Abstract: The present invention relates to a catalyst component for the (co)polymerization of olefins comprising titanium, magnesium, halogen and a mixed electron-donor and a catalyst for the (co)polymerization of olefins comprisin: (A) the catalyst component; (B) an organic aluminum compound; and (C) an organic silicon compound. The polymer with high and adjustable stereospecificity and broad molecular weight distribution can be prepared by using the catalyst.

Abstract: A method to prepare a polyolefin in the presence of a catalyst comprising: (A) a solid catalyst component prepared by reacting a homogenous solution consisting of (i) at least one member selected from the group consisting of metal magnesium and a hydroxylated organic compound, and oxygen-containing organic compounds of magnesium, (ii) at least one oxygen-containing organic compound of titanium and (iii) at least one silicon compound, first with (iv) at least one first organoaluminum halide compound of the formula: AlR5zX3−z  wherein R5 is a hydrocarbon group having from 1 to 20 carbon atoms, X is a halogen atom, and 1≦z≦2, and wherein the atomic ratio of gram atoms of Al in the component (iv) to gram atoms of Mg in the component (i) (Al/Mg) is from 0.1 to 2.

Abstract: A process for producing an olefin polymer using a catalyst in which (A) is a solid catalyst component which includes magnesium, titanium, halogen and an electron donative compound as essential constituents; (B) is an organoaluminum component; and (C) is at least two electron donative compounds (&agr;) and (&bgr;), wherein the pentad stereoregularity of a xylene insoluble fraction of a homopolyproylene is 0<mmrr/mmmm≦0.0068 when electron donative compound (&agr;) is used in combination with (A) and (B), and the pentad stereoregularity of a xylene insoluble fraction homoproplyene of a is 0.0068<mmrr/mmmm ≦0.0320 when electron donative compound (&bgr;) is used in combination with (A) and (B). A polypropylene produced in the process can be used to obtain a biaxially oriented film. (A) and (B). A polypropylene produced in the process can be used to obtain a biaxially oriented film.

Abstract: Novel compounds are disclosed comprising the skeletal unit depicted in Formula (I) wherein O is oxygen; N is nitrogen; R1 is hydrogen, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl; R3, R4, R5 and R6 are hydrogen or hydrocarbyl or heterohydrocarbyl groups containing 1 to 10 carbon atoms and the R12 groups are independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocarbyl and substituted heterocarbyl; A is carbon or silicon; and r is 1 or more; M is scandium, yttrium, or a Group IV or Group V metal or a lanthanide or actinide; T is the oxidation state of M and is II or greater; X represents a monodentate atom or group covalently or ionically bonded to M; L is a mono- or bidentate molecule datively bound to M, and n is from 0 to 5.

Abstract: A catalyst for &agr;-olefin polymerization obtained by contacting (A) a solid catalyst component containing a titanium compound which is obtained by treating a solid product obtained by contacting an organosilicon compound having an Si—O bond, an ester compound and an organomagnesium compound, with an ether compound, titanium tetrachloride and an acyl halide, and successively treating said treated solid with an mixture of an ether compound and titanium tetrachloride, or a mixture of an ether compound, titanium tetrachloride and an ester compound, (B) an organoaluminum compound and (C) an electron-donative compound, and a process for producing an &agr;-olefin polymer with the catalyst.

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: One aspect of the present invention relates to a catalyst system for use in olefinic polymerization, containing a solid titanium catalyst component prepared by contacting a titanium compound and a magnesium compound; an organoaluminum compound having at least one aluminum-carbon bond; and an organosilicon compound comprising at least one of cyclobutyl group. Another aspect of the present invention relates to a method of making a catalyst for use in olefinic polymerization, involving the steps of reacting a Grignard reagent having a cyclobutyl group with an orthosilicate to provide an organosilicon compound having a cyclobutyl moiety; and combining the organosilicon compound with an organoaluminum compound having at least one aluminum-carbon bond and a solid titanium catalyst component prepared by contacting a titanium compound and a magnesium compound.