Abstract: A method for producing a polyolefin in the presence of a catalyst comprising a transition metal compound and an organometallic compound, wherein a catalyst system is used which comprises (A) a solid catalyst component prepared by reacting a homogeneous solution containing (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 zirconium compound selected from the group consisting of oxygen-containing organic compounds and halogen-containing compounds of zirconium, and (III) at least one silicon compound selected from the group consisting of polysiloxanes and silanes, with (IV) at least one organoaluminum halide compound to obtain a solid product, isolating the solid product, and reacting this solid product with (V) at least one halogen-containing compound of titanium, and (B) at least one catalyst component selected from the group consisting of organoaluminum compounds.

Abstract: Provided are a propylene-ethylene block copolymer having MFR of from 0.01 to 1.0 g/10 min and comprised of (A) from 85 to 97% by weight a 25° C. xylene-insoluble fraction and (B) from 3 to 15% by weight of a 25° C. xylene-soluble fraction, wherein the fraction (A) is such that its stereospecificity index measured through 13C-NMR is at least 98.0%, its intrinsic viscosity [&eegr;] falls between 2.5 and 5.5 dl/g, and its weight-average molecular weight, Mw, measured through GPC and the content, S, of the fraction having a molecular weight of at most 104.5 therein satisfy S (wt. %)≦−5.3×10−6 Mw+7.58, and the fraction (B) is such that its ethylene unit content measured through 13C-NMR falls between 30 and 70% by weight, and its intrinsic viscosity [&eegr;] falls between 2.5 and 9.0 dl/g; and its blow-molded articles.

Abstract: The present invention relates to a method of polymerization or co-polymerization of olefin under the catalyst system which comprises (a) a solid complex titanium catalyst comprising of a magnesium compound, a titanium compound, and an internal electron donor; (b) an organometallic compound of metal of Group I or Group III on the Periodic Table; and (c) two of external electron donors comprising an external electron donor (1) and an external electron donor (2), wherein the ratio of the MFR (1) to the MFR (2) is 2˜10, the MFR (1) being that of the homopolymer (1) obtained by using said external electron donor (1) with said solid complex titanium catalyst (a) and the organometallic compound (b), and the MFR (2) being that of the homopolymer (2) obtained by using said external electron donor (2) under the identical polymerization reaction conditions of said external electron donor (1), and wherein the NMR pentads of the homopolymer (1) and the homopolymer (2), respectively, are 95.5% or more.

Abstract: A continuous process for obtaining propylene polymers in the presence of a catalytic system of the Ziegler-Natta type containing a catalytic solid comprising chlorine, magnesium and titanium atoms and at least one electron-donor compound, called internal donor, a cocatalyst which is an organoaluminium compound, and optionally an electron-donor compound, called external donor, comprising the following successive stages: (a) polymerization of propylene in liquid propylene to form, per g of titanium in the catalytic solid, from 11000 to 28000 g of a prepolymer chosen from among the homopolymers of propylene, and (b) gas-phase polymerization of propylene in one or more successive fluidized-bed reactors and in the presence of the prepolymer (a), of propylene, optionally in the presence of one or more other monomers chosen from among the &agr;-olefins containing from 2 to 12 carbon atoms to produce a final propylene polymer whose fraction of particles of diameter smaller than 125 &mgr;m (FP) is at most 10 wt %.

Abstract: The present invention provides an olefin polymerization catalyst component comprising a transition metal compound represented by general formula (1) LmCpnMX1X2  (1) an olefin polymerization catalyst containing the catalyst component as a transition metal component, and a method of producing a polyolefin using the catalyst. According to the present invention, polyolefins having a wide molecular weight distribution and excellent moldability and containing small amounts of low molecular weight components can be produced with high activity.

Abstract: A process for producing high density polyethylene in the presence of a metallocene catalyst system in two liquid full loop reactors in series, wherein in a first reactor a first polyethylene product is polymerized substantially by homopolymerization of ethylene and hydrogen, and in a second reactor serially connected to the first reactor downstream thereof a second polyethylene product is copolymerized from ethylene and an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, and a hydrogenation catalyst is introduced into the reactants downstream of the first reactor, the hydrogenation catalyst comprising a second metallocene catalyst of general formula: Cp2MXn where Cp is a substituted or unsubstituted cyclopentene dienyl group; M is a transition metal from Group IVB of the Periodic Table or vanadium; X is a halogen or a hydrocarbyl group having from 1 to 10 carbon atoms; and n is the valency of the metal M minus 2.

Abstract: A process is provided to prepare polyolefins having a multimodal molecular weight distribution comprising contacting at least one mono-1-olefin in a polymerization zone, under polymerization conditions, with a dual catalyst system comprising a first catalyst system which comprises a metallocene catalyst and a cocatalyst and a second catalyst system which comprises diimine nickel complexes which further comprise additional ligands selected from the group consisting of ∝-deprotoned-&bgr;-diketones, ∝-deprotoned-&bgr;-ketoesters, halogens and mixtures thereof. The resultant, recovered polymer has at least a bimodal, or broad, molecular weight distribution.

Abstract: A solid catalyst component for olefin polymerization prepared by a method which comprises contacting the following components (a), (b), (c) and (d): (a) a polymer carrier containing a carbonyl group; (b) an organometallic compound of metal of Group I, II or XIII of the Periodic Table; (c) a transition metal compound of Group IV of the Periodic Table; and (d) a phenol compound, a catalyst for olefin-polymerization comprising said solid catalyst component and an organoaluminum compound and/or organoaluminum oxide compound, and a method for producing an olefin polymer with said catalyst.

Abstract: A dual reactor process for the solution and (co)polymerization of ethylene uses two different types of catalysts in the two reactors. A catalyst having a phosphinimine ligand is used in the first reactor. A Ziegler Natta catalyst is used in the second reactor. The process of this invention is comparatively easy to control and may be used to produce polyethylene products having a broad molecular weight distribution. Linear low density produced according to this invention is well suited for the manufacture of molded goods and plastic films.

Abstract: The subject-matter of the present invention is thus a process for starting up a gas phase olefin polymerisation reaction carried out using a Ziegler-Natta type catalyst based on a transition metal in a fluidized-bed reactor, through which passes a reaction gas mixture comprising the olefin, an inert gas, hydrogen and optionally at least one comonomer and which operates under conditions of temperature and pressure which make it possible to start up the polymerization, characterized in that the partial pressure of the olefin and the rate of introduction of catalyst into the reactor are increased whilst maintaining the ratios of the partial pressures of the olefin to the hydrogen and to the optional comonomer or comonomers substantially constant.

Abstract: Olefins such as ethylene and propylene may be polymerized by using as catalysts novel selected transition metal complexes of bis(carboximidamidatonates) in which the carboximidamidatonate groups are connected together through covalent bonds by a bridging group. The resulting polymers are useful as molding and extrusion resins.

Abstract: A specified transition metal compound having two transition metals and two cyclopentadiene type anion skeletone in tis molecule and said metals are linked through an atom of Group XVI of the Periodic Table of the Elements, and olefin polymerization catalyst component comprising said transition metal compound, an olefin polymerization catalyst comprising said transition metal compound, a specific organoaluminum compound, and a specific boron compound, and a process for producing an olefin polymer using said olefin polymerization catalyst.

Abstract: A high molecular weight polyethylene prepared by preliminary polymerization is added at the time of main polymerization of an olefin, for example, propylene, to prepare an olefin (co)polymer composition comprising the above high molecular weight polyethylene finely dispersed as fine particles in the polyolefin, such as polypropylene, and a cross-linked structure is formed in the olefin (co)polymer composition. This process can provide a modified olefin (co)polymer composition improved in the strength in a molten state in terms of melt tension or the like and in crystallization temperature and excellent in moldability such as high-speed producibility, and a molded modified olefin (co)polymer composition excellent in properties such as heat resistance and rigidity.

Abstract: A catalyst system suitable for the polymerization of olefins comprising an olefin polymerization catalyst and an activator comprising the reaction product of (i) an aluminoxane or (ii) the reaction product of an alkylaluminum and water with a silicon-containing compound, for example diphenylsilane diol. Preferred catalysts are metallocene complexes. The activators provide an alternative to the traditional use of aluminoxanes alone.

Abstract: A process for producing high density polyethylene in the presence of a Ziegler-Natta catalyst system in two liquid full loop reactors in series, wherein in a first reactor a first polyethylene product is polymerized substantially by homopolymerization of ethylene and hydrogen, optionally with a minor degree of copolymerization of ethylene with an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, and in a second reactor serially connected to the first reactor downstream thereof a second polyethylene product is copolymerized from ethylene and an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, and a hydrogenation catalyst is introduced into the reactants downstream of the first reactor.

Abstract: Multiphase homo- or copolymers of C2-C10-alk-1-enes are prepared by a process in which polymerization is effected in the presence of two different catalyst systems in one reaction zone, one of the catalyst systems containing, as active components, a metallocene complex of the general formula (I) or (II) where M1 is a metal of group IVb, Vb or VIb of the Periodic Table, R1 and R2 are identical or different and are each hydrogen, C1-C10-alkyl, C1-C10-alkoxy, C6-C10-aryl, C6-C10-aryloxy, C2-C10-alkenyl, C7-C40-arylalkyl, C7-C40-alkylaryl, C8-C40-arylalkenyl or halogen, R3 and R4 are identical or different and are each hydrogen, halogen, C1-C10-alkyl which may be halogenated, C6-C10-aryl or an —NR210, —SR10, —OSiR310, —SiR310 or —PR210 radical, where R10 is halogen, C1-C10-alkyl or C6-C10-aryl, and R5 and R6 are identical or different and have the meanings stated for R3 and R4, with the proviso that R5 and R6 are not hydrogen.

Abstract: The invention provides catalysts which have a high polymerization activity, enable the obtaining of olefin polymers of wide molecular weight distribution, and which comprise (a)(a-1) a metallocene compound or (a-2) a titanium catalyst component containing magnesium, titanium, and halogen, (b) a compound of a transition metal from Groups 8 to 10 of the periodic table and is of the general formula shown below, and a cocatalyst component. ##STR1## The invention also provides olefin polymer compositions excellent in rigidity and impact resistance which can be produced using a catalyst comprising the transition metal compound (b) and which comprises a non-crystalline olefin polymer having a specific intrinsic viscosity, glass transition temperature and density, and another known olefin polymer.

Abstract: A process for polymerizing an alpha-olefin using either a catalyst formed by contacting a highly active solid titanium catalyst component, an organo-metallic compound of a metal of Group 1 to 3 of the periodic table, an organic halogen compound or a transition metal compound, and an organosilicon compound or a sterically hindered amine in an inert medium in the absence of an alpha olefin, or a catalyst prepared by preliminarily polymerizing an alpha olefin in the presence of a catalyst comprising the above four catalyst components, provided that the last one is an optional component. This process achieves the industrially advantage that the catalysts are highly active, and give a polymer having excellent stereoregularity.

Abstract: The present invention provides a catalyst system that exhibits unexpected control of desired properties in polyolefin products. The catalyst system includes a titanium-supported catalyst in combination with a mixture of tetraethoxysilane (TEOS) and dicyclopentyldimethoxy-silane (DCPMS). This catalyst system has been found to be effective in making polypropylene and polypropylene copolymers having relatively high melt flow rates and moderately broad molecular weight distribution.

Abstract: A method of forming a polymer that simultaneously provides an improved level of impact resistance and processability in which an .alpha.-olefin monomer is subjected to polymerization in the presence of a Ziegler-Natta catalyst system and a blend of electron donors including dicyclopentyldimethoxysilane (DCPMS) and propyltriethoxysilane (PTES). The polymer so formed will have a relationship between a first melt flow rate of a homopolymer formed by polymerizing an .alpha.-olefin monomer in the presence of a Ziegler-Natta catalyst system and a first electron donor (MFR (a)), and a second melt flow rate of a homopolymer formed polymerizing an .alpha.-olefin monomer in the presence of the Ziegler-Natta catalyst system and a second electron donor (MFR (b)), is defined by the equation:1.2.ltoreq.log [MFR(b)/MFR(a)].ltoreq.1.

Abstract: The present invention provides a Ziegler-Natta catalyst based on titanium and vanadium useful in solution processes for the polymerization of olefins having a low amount of aluminum and magnesium. The catalysts of the present invention have a molar ratio of magnesium to the first aluminum component from 4.0:1 to 8.0:1 and molar ratio of magnesium to titanium and vanadium from 4.0:1 to 8.0:1. The invention provides a novel catalyst preparation method to substantially increase the polymer molecular weight in the high temperature ethylene polymerization process.

Abstract: There is provided a process for preparing a polydiene comprising polymerizing a diene selected from the group consisting of butadiene, isoprene, or a mixture thereof under polymerization conditions in a gas phase reactor optionally in the presence of an inert particulate material and in the presence of a catalyst comprising (i) a rare earth metal component, (ii) a transition metal component selected from the group consisting of nickel compound, cobalt compound or titanium compound, and (iii) cocatalyst.

Abstract: A novel metallocene compound and a method for producing a polymer by using the metallocene as a polymerization catalyst. The present catalyst includes a neutral metallocene compound, a cationic metallocene compound, and the compound supported catalyst. The present catalyst can be used to produce a polymer having a characteristic structure and physical properties.

Abstract: Disclosed is a catalyst precursor, useful to make catalysts useful in the polymerization of olefins, comprising the product obtained by adding a preformed magnesium source to a solution comprising a solvent having dissolved therein a transition metal compound and an alkyl halide.

Abstract: Disclosed in an olefin polymerization catalyst comprising a transition metal compound having at least two transition metals in which at least one of said metals is bonded to a ligand having a cyclopentadienyl skeleton, at least one of said metals is selected from Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and lanthanoid metals and at least on of the others is selected from the specific transition metals; and an organoaluminum oxy-compound or an organoboron compound. Corresponding to the kind of the metal combined with said metal selected from Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and lanthanoid metals, the olefin polymerization catalyst exhibit a property to give polymers having a wide molecular weight distribution in spite of the catalyst system using one kind of a transition metal compound, or to give polymers having high molecular weight and be excellent in the polymerization activity at low polymerization temperature.

Abstract: The present invention provides a catalyst and a process for increased catalyst activity and polymer yield. The catalyst system used in the process includes at least two supported metallocene catalyst precursor in combination with an oxyorganoaluminum. The process can be applied to the polymerization of olefins, preferably olefin of three carbon atoms and higher, particularly propylene. The catalyst activity and polymer yield for a dual supported metallocene catalyst are increased over that for a single supported metallocene catalyst. The polymer produced by this dual supported metallocene system has a relatively broad molecular weight distribution.

Abstract: Homo- or co-polymers derived from one or more alpha-olefins having a number average molecular weight of up to 15,000 and an isotacticity of 75% or greater, and their use as Cold Flow Improvers in crude, fuel or lubricating oil.

Abstract: Presence of a catalyst formed from (A) a transition metal compound comprising (A-1) a transition metal atom, (A-2) a hetero atom-containing ligand containing a heteroatom selected from oxygen, sulfur, nitrogen and phosphorus capable of forming a bond with the transition metal atom, and (A-3) a ligand having a conjugated .pi. electron through which the ligand can be bonded to the transition metal atom (A-1), and (B) an aluminoxane. The transition metal compound is pre-treated with (C) an organometallic compound, or (D) a halogen-containing inorganic compound of an element of Group III, IV or V of the periodic table in an organic solvent.

Abstract: The present invention is a catalyst system to produce polymer blends in a single reactor, polymer blends of isotactic polyolefins and syndiotactic polyolefins. The catalyst system is a combination of at least one metallocene catalyst and at least one conventional supported Ziegler-Natta catalyst. The multi-catalyst system is obtained by mixing the components of at least one metallocene catalyst and at least one conventional supported Ziegler-Natta catalyst. The metallocene catalyst comprises solid complx of a metallocene compound and an ionizing agent. The conventional supported Ziegler-Natta catalyst comprises an aluminum alkyl and a transition metal compound with, optionally, an electron donor.

Abstract: Solid precursor of a catalytic system for the polymerization of olefins, containing at least one neutral halogenated metallocene derived from a transition metal, the latter being linked to at least one halogen atom, and at least one ionizing agent.Process for the preparation of this solid precursor, according to which a compound based on the neutral halogenated metallocene is mixed with a compound based on the ionizing agent in a heterogeneous medium. Catalytic system comprising an organometallic compound derived from a metal chosen from groups IA, IIA, IIB, IIIA and IVA of the Periodic Table, and a solid precursor described above. Process for the polymerization of olefins, in which this catalytic system is used.

Abstract: Ethylene copolymers are disclosed herein which are each derived from ethylene and an olefin of C.sub.3 to C.sub.20 and in which any quaternary carbon atom is not present in a polymeric main chain; the activation energy (Ea) of melt flow is in the range of 8 to 20 kcal/mol; and (1) a ratio between a Huggins coefficient (k.sup.1) of the copolymer and a Huggins coefficient (k.sup.2) of a straight-chain ethylene polymer having the same intrinsic viscosity meets the equation 1.12<k.sup.1 /k.sup.2 .ltoreq.5, or (2) a molar ratio ?CH.sub.3 /CH.sub.2 ! of a methyl group to a methylene group in a molecular chain is in the range of 0.005 to 0.1, and the equation Tm.gtoreq.131-1,340 ?CH.sub.3 /CH.sub.2 ! is met, or (3) Mw and a die swell ratio (DR) meet the equation DR>0.5+0.125.times.log Mw.

Abstract: A process for producing an alpha-olefin polymer, which comprises polymerizing an alpha-olefin in the presence of a catalyst formed from (A) a transition metal compound comprising (A-1) a transition metal atom, (A-2) a hetero atom-containing ligand containing a heteroatom selected from oxygen, sulfur, nitrogen and phosphorus capable of forming a bond with the transition metal atom, and (A-3) a ligand having a conjugated .pi. electron through which the ligand can be bonded to the transition metal atom (A-1), and (B) an aluminoxane. The transition metal compound may be pre-treated with (C) an organometallic compound, or (D) a halogen-containing inorganic compound of an element of Group III, IV or V of the periodic table.

Abstract: A process for effectively producing a cyclic olefin polymer and a cyclic olefin/alpha-olefin copolymer without opening the cyclic olefin, is disclosed. Further, a novel cyclic olefin/alpha-olefin copolymer prepared by the above-mentioned process, compositions and molded articles comprising the novel copolymer, are also disclosed. In the process for producing a cylcic olefin based polymer according to the present invention, homopolymerization of a cyclic olefin or copolymerization of a cyclic olefin and an alpha-olefin is effected in the presence of a catalyst comprising, as main ingredients, the following Compounds (A) and (B), and optionally Compound (C):(A) a transition metal compound;(B) a compound capable of forming an ionic complex when reacted with a transition metal compound; and(C) an organoaluminum compound.

Abstract: There are disclosed a catalyst for producing an aromatic vinyl compound-based polymer composition which catalyst comprises (A) at least two different transition metal compounds each having one .pi.-ligand and (B) an ionic compound comprising a noncoordinate anion and a cation and/or an aluminoxane, and (C) a Lewis acid to be used as the case may be; and a process for producing an aromatic vinyl compound-based polymer composition having a high degree of syndiotactic configuration in its aromatic vinyl chains which process comprises polymerizing an (a) aromatic vinyl compound and (b) an olefinic compound and/or a diolefinic compound in the presence of the above catalyst.

Abstract: The present invention is a process for producing a polymer blend in a single reactor, specifically a polymer blend of isotactic polyolefins and syndiotactic polyolefins. The catalyst system is a combination of at least one metallocene catalyst and at least one conventional supported Ziegler-Natta catalyst. The multi-catalyst system is obtained by mixing the components of at least one metallocene catalyst and at least one conventional supported Ziegler-Natta catalyst. The metallocene catalyst comprises a metallocene compound and an ionizing agent. The conventional supported Ziegler-Natta catalyst comprises an aluminum alkyl and a transition metal compound with, optionally, an electron donor.

Abstract: Olefin is polymerized using a catalyst comprising a solid catalyst component and an organometallic compound, the solid catalyst component being prepared by reacting 1 a reaction product obtained by reacting the reaction product of Si oxide and/or Al oxide and Ti compound or both Ti compound and V compound (Ti.V component) with organic Al compound, with 2 a reaction product obtained by the reaction of Mg halide, a compound of the general formula Me(OR).sub.n X.sub.z-n and Ti.V component (optional component), and further reacting the reaction product of the above 1 and 2 with 3 a compound of the general formula R.sub.p Si(OR).sub.q X.sub.4-p-q.

Abstract: Catalytic solid for the (co)polymerisation of at least one olefin, comprising a coprecipitate of magnesium and of at least one transition metal, obtained by means of a process comprising the preparation of a mixture of a magnesium compound, such as the chloride or a magnesium alcoholate, and of a compound denoted by one of the formulae MY.sub.x (O--R').sub.t-x and M'O.sub.y (O--R").sub.s-2y and the treatment of the resulting mixture with a complex of formula M"(A)Al.sub.2 (X',X").sub.8 where X' and X" denote halogens, M and M' transition metals of groups IVB and VB, M" a transition metal of group IVB, A an aromatic hydrocarbon, Y a halogen or a group (O--R'"), and R', R" and R'" an alkyl, aryl or cycloalkyl group.

Abstract: A process for effectively producing a cyclic olefin polymer and a cyclic olefin/alpha-olefin copolymer without opening the cyclic olefin, is disclosed. Further, a novel cyclic olefin/alpha-olefin copolymer prepared by the above-mentioned process, compositions and molded articles comprising the novel copolymer, are also disclosed. In the process for producing a cylcic olefin based polymer according to the present invention, homopolymerization of a cyclic olefin or copolymerization of a cyclic olefin and an alpha-olefin is effected in the presence of a catalyst comprising, as main ingredients, the following Compounds (A) and (B), and optionally Compound (C):(A) a transition metal compound;(B) a compound capable of forming an ionic complex when reacted with a transition metal compound; and(C) an organoaluminum compound.

Abstract: Disclosed in an olefin polymerization catalyst comprising a transition metal compound having at least two transition metals in which at least one of said metals is bonded to a ligand having a cyclopentadienyl skeleton, at least one of said metals is selected from Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and lanthanoid metals and at least on of the others is selected from the specific transition metals; and an organoaluminum oxy-compound or an organoboron compound. Corresponding to the kind of the metal combined with said metal selected from Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and lanthanoid metals, the olefin polymerization catalyst exhibit a property to give polymers having a wide molecular weight distribution in spite of the catalyst system using one kind of a transition metal compound, or to give polymers having high molecular weight and be excellent in the polymerization activity at low polymerization temperature.

Abstract: A composition, which can be used as catalyst for producing an olefin polymer having a multimodal molecular weight distribution, is provided that comprises a transition metal-containing catalyst, a metallocene, and a boron-containing organoaluminoxane, wherein each component of the composition is present in an effective amount so that an olefin polymer having a multimodal molecular weight distribution can be produced using the composition as catalyst, preferably in the presence of a cocatalyst. Also provided is a process for preparing the composition which comprises: (1) contacting a transition metal-containing catalyst with an organoaluminoxane dispersed in a solvent to form a slurry; (2) combining the slurry with a boroxine to prepare a combination of a transition metal-containing catalyst and boron-containing organoaluminoxane; and (3) contacting the combination with a metallocene. Further provided is a process for polymerizing an olefin to prepare an olefin polymer using the composition.

Abstract: A support containing methylalumoxane and derivatives thereof is described which is formed by an incipient impregnation technique. The most preferred support is silica. Incipient impregnation in accordance with the invention provides a supported alumoxane, methylalumoxane, which substantially eliminates the problem of fluidized bed reactor fouling when methylalumoxane is introduced into the reactor during its operation. In accordance with the invention, the process comprises providing methylalumoxane activated metallocene compound in particulate form as catalysts in fluidized bed gas phase operation.

Abstract: A solution process for the preparation of high molecular weight polymers of alpha-olefins selected from the group consisting of homopolymers of ethylene and copolymers of ethylene and C.sub.3 -C.sub.12 higher alpha-olefins is disclosed. Ethylene and/or mixtures of ethylene and C.sub.3 -C.sub.12 higher alpha-olefins are polymerized under non-isothermal conditions in a tubular reactor or in a system of reactors which operate under different conditions, in the presence of a catalytic amount of a titanium-containing coordination catalyst in an inert solvent at a temperature in excess of 105.degree. C. The improvement is characterized in that:(a) the catalyst is activated with a solution of a mixture of aluminum alkyl and alkoxy aluminum alkyl in inert solvent; and(b) the process is controlled by adjusting the ratio of aluminum alkyl to alkoxy aluminum alkyl in the mixture of (a). The aluminum alkyl is of the formula AlR.sub.n X.sub.3-n and the alkoxy aluminum alkyl is of the formula AlR'.sub.m OR".sub.

Abstract: A process is disclosed for the polymerization of olefins, using (i) a catalyst and (ii) an organometallic activator from Groups I, II or III of the Periodic Table at temperatures between 20.degree. and 250.degree. C., and pressure up to 200 bar, in solution, or in suspension in an inert liquid hydrocarbon, at temperatures between 160.degree. and 350.degree. C., under pressures of between 400 and 3000 bar, in a continuous manner in a reactor where the mean residence time of the catalyst is between 1 and 150 seconds. The catalyst comprises at least one titanium compound, at least one halogen-containing organoaluminum compound and at least one inorganic magnesium compound in suspension in at least one .alpha.,.omega.-dihaloalkane. The titanium compound is essentially a titanium (III) compound, the total content of titanium (II) and titanium (IV) being less than or equal to 15% of the total content of titanium.

Abstract: In the polymerization of olefins with a vapor phase fluidized bed reactor, the improvement comprises the steps of feeding seed polymer particles and the reaction is then started after feeding an organoaluminum compound on a prescribed basis, thereby avoiding the formation of sheet-like polymer in the initial period of the reaction and the lowering of the bulk density of the product polymer.

Abstract: A catalytic component having controlled structure for use in combination with a cocatalyst for the polymerization of ethylene, and being the product of the process of subjecting a component consisting essentially of titanium, magnesium, and chlorine to a reduction treatment and after such treatment contacting the component with a transition metal chlorine-containing compound and process of polymerizing ethylene using such catalytic component to produce polymers having a broad molecular weight distribution.

Abstract: The invention generally relates to a catalyst, particularly a metallocene catalyst and catalyst system useful in the polymerization of olefins into a polymer product. The polymer product has a broad molecular weight distribution, a high molecular weight and a narrow composition distribution and is easily processable.

Abstract: The present invention relates to a continuous process for the polymerization of an alpha-olefin having from 2 to 12 carbon atoms, which is carried out in a gas phase polymerization reactor by bringing a gaseous reaction mixture, containing the alpha-olefin to be polymerized, into contact with a catalyst system of the Ziegler-Natta type consisting of a solid catalyst comprising at least one compound of a transition metal belonging to groups IV, V or VI of the Periodic Table, of the elements, and of a cocatalyst comprising at least one organometallic compound of a metal belonging to groups II or III of the Periodic Table in which the polymerization reactor is fed with alpha-olefin at a constant rate.

Abstract: The present invention relates to a method for activating coordination catalysts suitable for the polymerization of alpha olefins using a alkoxy aluminum alkyl compound prepared by mixing an alcohol and an alkyl aluminum. The activator retains its activity and is easy to prepare simplifying the polymerization process.

Abstract: Polyolefins having better particle properties are obtained by polymerizing olefins in the presence of a catalyst comprising a solid catalyst component and an organometallic compound, the said solid catalyst component being prepared by reacting the following components [I] and [II] and further reacting the resulting reaction product with the following component [III]:[I] a reaction product obtained by reacting:(1) a silicon oxide and/or an aluminum oxide, and(2) a titanium compound, or a titanium compound and a vanadium compound, and further reacting the resulting reaction product with:(3) an organoaluminum compound;[II] a reaction product obtained by the reaction of:(1) a magnesium halide, and(2) a compound represented by the general formula Me(OR).sub.n X.sub.z-n wherein Me represents an element of Groups I to IV in the Periodic Table, z represents the valence of the element Me, n is 0<n.ltoreq.

Abstract: A solution process, and a catalyst therefor, for the preparation of high molecular weight polymers of alpha-olefins viz. homopolymers of ethylene and copolymers of ethylene and C.sub.3 -C.sub.12 alpha-olefins, is disclosed. The process is operated under solution polymerization conditions at 105.degree.-320.degree. C. The catalyst is obtained from titanium tetrahalides, vanadium oxytrihalides and organoaluminum compounds, in which an admixture of catalyst components is heat-treated at 180.degree.-250.degree. C. and subsequently cooled to a temperature of less than 150.degree. C. Additional vanadium oxytrihalide is then added. The resultant catalyst solution is activated with an aluminum compound. The catalyst has good activity, showing superior activity to catalysts in which additional vanadium oxytrihalide is not added or added at temperatures above 150.degree. C.