Abstract: Azeotropic or azeotrope-like mixtures of 1,3-dichloro-3,3-difluoroprop-1-ene (HCFO-1232zd) and hydrogen fluoride (HF). Such compositions are useful as a feed stock or intermediate in the production of 1,1,1,3,3-pentafluoropropane (HFC-245fa),1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), and 1,3,3,3-tetrafluoropropene (HFO-1234ze).

Abstract: Polymerization reactor systems providing real-time control of the average particle size of catalyst system components are disclosed. Methods for operating such polymerization reactor systems also are described.

Abstract: Polymerization reactor systems providing real-time control of the average particle size of catalyst system components are disclosed. Methods for operating such polymerization reactor systems also are described.

Abstract: There is provided a complex having a specified chemical structure and an asymmetric catalyst using such a complex. Further, an epoxidation of amine or ketone is enantioselectively conducted by using such an asymmetric catalyst.

Abstract: A process for the catalytic fluorination of hydrochlorocarbons and hydrochlorofluorocarbons in the liquid phase. The process is useful for fluorinating hydrochloropropanes, hydrochlorofluoropropanes, hydrochloropropenes and hydrochlorofluoropropenes and most particularly useful for fluorinating 1,1,1,3,3-pentachloropropane to 1,1,1,3,3-pentafloropropane.

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: Process for the polymerization of olefins using a catalytic system comprising a solid precursor containing at least one neutral halogenated metallocene derived from a transition metal and at least one ionizing agent, and an organometallic compound derived from a metal chosen from groups IA, IIA, IIB, IIIA, and IVA of the Periodic Table.

Abstract: A polymer supported catalyst comprises Ziegler-Natta catalysts immobilized on a magnesium-modified polymer support. The catalyst support is prepared by (1) dissolving a carboxyl group-containing polymer in a solvent and precipitating the polymer in a polar non-solvent, (2) wet-grinding the precipitated polymer, and (3) mixing the ground polymer with an organomagnesium compound or a complex of an organomagnesium compound and an organoaluminum compound to give a magnesium-modified polymer support. Optionally, the resulting magnesium-modified support is treated with a halogen-containing silicon compound. The catalysts may be loaded onto the support by reacting the magnesium-modified support with a transition metal compound to form a catalyst constituent, and then combining the catalyst constituent with an appropriate organo-metallic compound.

Abstract: A catalyst component useful for (co)polymerizing ethylene under high temperatures and pressures comprising the reaction product obtained by treating a magnesium halide supported titanium halide precursor with Lewis acid, thoroughly washing the solid reaction product therefrom and prepolymerizing the washed solid product with an alpha-olefin having from 4-12 carbon atoms.

Abstract: Ultra-high-molecular-weight polyolefin fine powder characterized in that said fine powder has an intrinsic viscosity measured in decalin at 135.degree. C. of at least 10 dl/g and an average particle diameter in the range of 1-80 .mu.m, at least 20 weight % of the powder passing through 350 Tyler mesh screen.

Abstract: A catalyst composition for the polymerization of propylene comprising a catalytic solid comprising a titanium halide and a magnesium halide and isoprenyl aluminum associated therewith and the process of polymerizing propylene using such catalyst.

Abstract: A process for the stereoregular polymerization of alpha olefins which comprises polymerizing an alpha olefin having from 2 to 8 carbon atoms in the presence of a catalyst comprising: (a) a solid supported titanium tetrahalide complex, wherein said complex is prepared by contacting a mechanically pulverized solid support with titanium tetrahalide in the absence of mechanical pulverization, and (b) a cocatalyst comprising a mixture of a dialkyl aluminum halide and a dialkyl magnesium or alkyl lithium compound.

Abstract: A novel highly efficient process is disclosed for the production of substantially amorphous ethylene-propylene copolymers. The polymers have properties which make them applicable for use, e.g., as hot melt adhesives, as blending components in roofing materials, and as cable and wire flooding agents.

Abstract: A novel process for the production of substantially amorphous interpolymers of propylene, ethylene and optionally a third alpha-olefin comonomer having between 4 and 8 carbon atoms per molecule is disclosed. The polymers have properties which make them applicable for use, e.g., as hot melt adhesives and as blending components in roofing materials.

Abstract: This invention relates to pretreating the support material for a polymerization catalyst comprising magnesium chloride with an active hydrogen compound such as an organic acid phosphate or a phenol in order to transform substantially elemental magnesium and other impurities. The impure magnesium chloride originates as a by-product from the manufacture of magnesium alkyls by the reaction of alkyl chlorides with elemental magnesium. Succeeding steps are activating the support material with an electron donor and treating the activated product with a titanium halide. The invention also includes the novel catalytic component containing titanium halide, itself, the process for making that component, use of this catalytic system for polymerizing olefins such as propylene, and the purification step for magnesium chloride, itself.

Abstract: The invention relates to a catalytic titanium component useful for the polymerization of alkenes-1 and for the copolymerization of alkenes-1 with each other or with ethylene, containing a halogenated titanium compound, an electron donor, and a metal halide obtained by conversion of an organic metal compound with a halogenating agent of the formula RX.sub.m, wherein R is a hydrocarbon group, a hydrogen atom or a halogen atom, X is a halogen atom, and m is a whole number from 1-10. The catalytic titanium component according to the invention is characterized in that the metal halide has been obtained by conversion of a combination of an organic aluminium compound and an organic magnesium compound with the halogenating agent into the corresponding metal halide, for instance by means of a reaction with hydrogen chloride or an alkyl chloride.

Abstract: A catalyst system for use in the polymerization of ethylene under high pressure and temperature containing an alkyl-aluminum or alkylsiloxalane activator and a compound of the formula:(TiCla) (MgCL.sub.2).sub.y (AlCl.sub.3)z (RMgCl).sub.bin whicha is from 2 to 3;y is 2 or more;z is from 0 to 1/3;b is from 0 to 1; andR is an aliphatic or aromatic hydrocarbon radical.

Abstract: Provided is an olefin polymerization catalyst comprising the combination of:[I] a solid catalyst component comprising a solid material obtained by contacting the following components (1) to (4) and a titanium compound (5) supported on said solid material:(1) a magnesium halide,(2) a compound represented by the general formula ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are each a hydrocarbon radical having 1 to 24 carbon atoms, alkoxy, hydrogen, or halogen, R.sup.4 is a hydrocarbon radical having 1 to 24 carbon atoms and n is 1.ltoreq.n.ltoreq.30,(3) a compound represented by the general formula ##STR2## wherein R.sup.5 is hydrogen, halogen, or a hydrocarbon radical having 1 to 24 carbon atoms, R6 is a hydrocarbon radical having 1 to 24 carbon atoms, and r, p and q are integers selected from the following ranges: 1.ltoreq.r.ltoreq.3, 0.ltoreq.p<6, 0.ltoreq.q<6, provided 1.ltoreq.r+p+q<6, and(4) a compound represented by the general formula R.sup.7 -O-R.sup.8 wherein R.sup.7 and R.sup.

Abstract: New catalysts for the polymerization of olefins and more particularly of ethylene and mixtures thereof with higher alpha-olefins and/or diolefins, are disclosed. The catalysts are prepared by mixing (a) a hydride or an organo-metallic compound of a metal belonging to Groups I, II or III of the Mendelyeev Periodic Table with (b) the product obtained by contacting a titanium compound (1) with a mixture of an anhydrous magnesium halide (2) in a particular active form and an anhydrous compound of a metal belonging to Group I or II of said Periodic Table, (3). In the particular active form to which it is converted, during or prior to the contacting the anhydrous magnesium halide is characterized in that, in its X-ray spectrum, the diffraction line which is most intense in the X-ray spectrum of the normal, inactive magnesium halide shows a decreased intensity, and/or the active magnesium halide has a surface area greater than 3 m.sup.2 /g.

Abstract: Solid polyolefin catalysts are adapted for use in low pressure gas phase fluid bed polymerization processes by being mixed with selected particulate organic support materials in a high speed bladed finishing device so as to cause the catalysts materials to become embedded in, and/or adhered to, softened particles of the support material.

Abstract: Stereospecific polymerization of .alpha.-olefins is carried out with use of a catalyst comprising an activated titanium component obtained by treating copulverized products of magnesium halide, an organosilicon compound having at least one alkoxyl group and a halogenated hydrocarbon with titanium halide, an organoaluminum compound and an electron donative compound.

Abstract: An olefin polymerization catalyst component produced by impregnating polyethylene with a pulverized solid olefin polymerization catalyst containing a Group 4b or 5b transition metal, for example a pulverized magnesium chloride containing titanium is impregnated in low molecular weight polyethylene by copulvering, then subjecting the impregnated polymer particles to shear in an inert medium at about the softening point of the polyethylene, which when used as a cocatalyst with an organoaluminum compound produces polymers of improved morphology having a more regular shape and higher bulk density than pulverized catalyst alone.

Abstract: Polymerization catalysts, particularly catalysts for the polymerization of olefins, are disclosed. The catalysts are prepared by mixing(A) an organometallic compound or hydride of a metal belonging to Groups I to III of the Mendelyeev Periodic Table; with(B) the product obtained by contacting (1) an addition product obtained by reacting a di-, tri-, or tetravalent titanium compound with an electron-donor compound, with (2) an anhydrous magnesium halide, in particular anhydrous MgCl.sub.2 or MgBr.sub.2, which is either preactivated or mixed with the Ti compound under conditions which result in its activation; or by contacting (A) with(B') the product obtained by contacting a di-, tri-, or tetravalent Ti compound with an electron-donor compound and a support consisting of an anhydrous Mg halide, in particular MgCl.sub.2 or anhydrous MgBr.sub.2, which is either preactivated or mixed with the Ti compound and electron-donor under conditions such that the Mg halide is activated.

Abstract: Polymerization catalysts, particularly catalysts for the polymerization of olefins, are disclosed. The catalysts are prepared by mixing hydrides of organometallic compounds of metals belonging to Groups I to III of the Mendelyeev Periodic Table with products obtained by contacting (1) titanium compounds of the formulaMpTi.sub.m X.sub.(n. m) +pin which M is an alkaline metal or the group NR.sub.4 in which the valences of the quaternary nitrogen atom are satisfied by hydrogen and/or by hydrocarbon groups or is part of a heterocyclic ring; X.sub.n. m substituents are NR.sub.2 group in which the Rs represent hydrogen, and/or hydrocarbon groups or, in part, halogen atoms; n is the titanium valence; m is a whole number from 1 to 3 inclusive; and p is zero or a whole number from 1 to 3, inclusive; with (2) carriers consisting of anhydrous Mg halides which are in active form or converted to active form by the conditions under which the carriers are contacted with the titanium compounds.

Abstract: Highly active catalysts for the polymerization of olefins are disclosed. The catalysts are prepared by mixing a hydride or organometallic compound of a metal belonging to Groups I, II or III of the Mendelyeev Periodic Table with the product obtained by contacting an oxygenated Ti compound in which one or more Ti atoms are bound through oxygen atoms to organic radicals with an activated anhydrous Mg dihalide. The polymerization of ethylene by means of said catalysts is also disclosed.

Abstract: Polymerization of olefins in the presence of a catalyst system comprising titanium-containing component (A) associated with a milled blend of at least two different silica-containing materials having different MI (polymer melt index) potentials in which at least one of the silicas has been treated with a chemical agent which reacts with OH groups on the surface of the silica and a dihydrocarbylmagnesium compound, and a cocatalyst component (B) comprising an organoaluminum compound. Ethylene polymers having broad molecular weight distribution are obtained using the catalysts defined herein.

Abstract: A process for the preparation of homopolymers and copolymers of .alpha.-monoolefins by means of a Ziegler-Natta catalyst system comprising (1) a halide of trivalent titanium, (2) an oxygen compound (ester) having a specific formula and (3) an aluminum-alkyl, the titanium halide (1) and the oxygen compound (2) being milled together before use, wherein the catalyst system employed contains, as a further component, (4) a phenolic compound of the formula ##STR1## where R.sup.3 is C.sub.1 -C.sub.6 -alkyl, R.sup.4 is hydrogen or C.sub.1 -C.sub.6 -alkyl, p is an integer from 0 to 5 and q is an integer from 1 to 5.

Abstract: A process for the homopolymerization or copolymerization of olefins is disclosed, which is carried out in the presence of an improved catalyst comprising a solid catalyst component and an organometal compound, said solid catalyst component being obtained by the reaction of: (a) a magnesium halide, (b) a compound represented by the formula: Me(OR).sub.n X.sub.z-n where Me is any of the Group I-VIII elements of the Periodic Table, excluding Al, Si, Ti and V, R is a hydrocarbon residual group having 1-24 carbon atoms, X is a halogen atom, z represents the valence of Me and n is 0<n.ltoreq.z, and (c) a compound represented by the formula: Si(OR').sub.m X.sub.4-m where R' is a hydrocarbon residual group having 1-20 carbon atoms, X is a halogen atom, and m is 0.ltoreq.m.ltoreq.4, and (d) a titanium compound and/or a vanadium compound. The resulting polymers are characterized by a large bulk density, a narrow range of molecular weight distribution, and small amounts of hexane extraction.

Abstract: A process for the homopolymerization or copolymerization of olefins is disclosed, which is carried out in the presence of a catalyst system comprising the combination of at least one organometallic compound with a component resulting from the reaction of (a) a magnesium halide, (b) a compound represented by the formula, Al(OR).sub.n X.sub.3-n, where R is a hydrocarbon residual group having 1 to 20 carbon atoms, X is a hydrogen atom, and n is 0.ltoreq.n.ltoreq.3, (c) a compound represented by the formula, Si(OR').sub.m X.sub.4-m, where R' is a hydrocarbon residual group having 1 to 20 carbon atoms, X is a halogen atom, and m is 0.ltoreq.m.ltoreq.4, and (d) a titanium compound and/or a vanadium compound. The resulting polymers have a large bulk density and a narrow range of molecular weight distribution.

Abstract: Catalysts useful in the polymerization of olefins, more particularly of ethylene and mixtures thereof with alpha-olefins and/or diolefins, are disclosed. The new catalysts are obtained by mixing a halide of titanium or vanadium in which the metal has a valency lower than 4, with a support comprising an anhydrous magnesium or zinc halide in an active form under particular conditions, and then activating the resulting product with a hydride or organometallic compound of a metal belonging to Groups I to III, inclusive, of the Mendelyeev Periodic System.

Abstract: A process for producing a polymer or copolymer of an olefin containing at least 3 carbon atoms which comprises polymerizing or copolymerizing at least one olefin containing at least 3 carbon atoms, or copolymerizing the olefin with to 10 mole % of ethylene and/or a diolefin in the presence of a catalyst composed of (A) a magnesium-containing solid titanium catalyst component and (B) an organometallic compound of a metal of Groups I to III of the periodic table; wherein the solid titanium catalyst component (A) is a composition formed by contacting(i) a reaction product of an organic magnesium compound containing magnesium directly bonded to at least one carbon atom with an organic silicon-containing compound selected from the group consisting of organic silanols containing at least one hydroxyl group directly bonded to silicon and organopolysiloxanes,(ii) an organic acid ester, and(iii) a titanium compound.

Abstract: A process for polymerizing ethylene in the presence of a catalyst system comprising at least two halogen compounds of transition metals, one of which has the formula (TiCl.sub.3,Y3 AlCl.sub.3)(MY.sub.3).sub.x (MgYZ).sub.y, where M is a transition metal of Group VB or V1B, X is a halogen and 0.3.ltoreq.x.ltoreq.3, 0.ltoreq.y.ltoreq.20, and a Group I to III hydryde or organometallic activator and the mean residence time of the catalyst system in the polymerization reactor is between 2 and 100 seconds.

Abstract: Catalysts useful in the polymerization of olefins, more particularly of ethylene and mixtures thereof with higher alpha-olefins and/or diolefins, are disclosed. The new catalysts are obtained by mixing a hydride or organometallic compound of a metal belonging to Groups I to III of the Mendelyeev Periodic System with the product obtained by contacting a titanium tetrahalide with a support comprising an anhydrous magnesium or zinc halide in an active form, under particular conditions.

Abstract: A process for polymerizing ethylene using a catalyst component prepared by pretreating a magnesium dihalide with selected organic oxy compounds and then reacting the pretreated magnesium dihalide with a halogenated titanium compound.

Abstract: A process for the preparation of an olefin polymerization catalyst component which comprises contacting a solid composition obtained by combining a magnesium halide, an electron donor and a tetravalent titanium compound, this composition being substantially free from aluminum compounds, with a liquid medium comprising a halide of B, Al, Ga, In, Tl, Sn or Sb, these elements being present in their highest valency state or a halide of tetravalent Te, and removing from the catalyst component substantially all metal halide originating from the liquid medium as by washing the catalyst component with a hydrocarbon or halohydrocarbon liquid.

Abstract: A high activity supported catalytic component obtained by pulverizing together (a) an anhydrous magnesium halide and (b) a titanium compound in the concomitant presence of 0.1 to 20 wt. % of (c) a liquid aromatic hydrocarbon and/or a liquid aromatic hydrocarbon halide, within the supported catalytic component, at temperature between 0.degree. and 100.degree. C. at which the liquid aromatic hydrocarbon and/or the liquid aromatic hydrocarbon halide remains in a liquid state throughout the whole range of temperature during the pulverization; and a method in which .alpha.-olefin is homo- or co-polymerized in the presence of a catalytic system comprising the high activity supported catalytic component, an organo-aluminum compound and an electron donor.

Abstract: A process for the production of ethylenic polymers, characterized in that ethylene is homopolymerized or ethylene with .alpha.-olefin is copolymerized by the use of a catalyst system comprising:(A) a solid catalyst component prepared by treating (1) a solid ingredient containing at least a magnesium atom, a halogen atom and a transition metal element with (2) at least a cyclic organic compound; and(B) an organoaluminum compound; or(A) the solid catalyst component;(B) the organoaluminum compound; and(C) an electron donor compound; and the catalyst systewm as obtained in the above-described manner.Ethylenic polymers having a narrow distribution of molecular weight, having suitability for use in injection molding and having excellent powder characteristics can be produced, and by using this polymer, film having excellent optical characteristics can be produced.

Abstract: Stereospecific polymerization of .alpha.-olefins is carried out with use of a catalyst system comprising an activated titanium compound, an organoaluminum compound and an electron donative compound. The activated titanium compound is obtained by copulverizing magnesium halide, a halongenated hydrocarbon and an orthocarboxylic acid ester and then treating the copulverized product with titanium halide.

Abstract: In a process for producing an olefin polymer or copolymer by polymerizing an alpha-olefin having at least 3 carbon atoms or copolymerizing such alpha-olefins with each other or such an alpha-olefin with up to 20 mole % of ethylene and/or a diene in the presence of a catalyst comprising (1) a solid titanium catalyst component having magnesium, halogen, titanium, phosphorus and a carboxylic acid ester and (2) an organometallic compound of a metal of Groups I to III of the Mendelejeff's periodic table; the improvement wherein said catalyst is composed of (A) the solid titanium catalyst component (1) in which the molar ratio of the phosphorus to the carboxylic acid ester is from about 0.05 to about 2 and which has a specific surface area of not less than about 40 m.sup.2 /g, (B) the organometallic compound (2), and (C) an electron donor; and a catalyst used for aforesaid process.

Abstract: According to this invention, there is provided a process for preparing a low-crystalline soft or semi-hard copolymer, characterized in that 90 to 98 mole % of propylene, 0.2 to 9 mole % of ethylene and 0.2 to 9 mole % of a straight-chained (.alpha.-olefin having not less than four carbon atoms are copolymerized using a catalyst, said catalyst comprising (1) a solid substance containing magnesium and titanium, (2) an organometallic compound and (3) an electron donor.

Abstract: A new improved catalyst system for alpha-olefin type polymerizations includes a metal alkyl compound selected from the group consisting of R.sub.2 WY or R.sub.3 W and an organomagnesium compound R'MgX in combination with a Group IVB-VIII transition metal compound. The improved catalyst system provides both increased polymerization activity and polymers having a high degree of isotactic stereoregularity.

Abstract: A supported titanium catalyst component is produced by cogrinding an organo aluminum catalyst component with a supported titanium (IV) halide on a magnesium halide. The resulting supported titanium halide catalyst component, when employed with an organo aluminum catalyst component to form a catalyst system is highly useful for the stereoregular polymerization of .alpha.-olefins as well as the copolymerization of .alpha.-olefins.

Abstract: Alpha-olefins are polymerized with a catalyst containing (1) TiCl.sub.3 /AlCl.sub.3 and (2) aluminum dialkyl chloride wherein (1) is prepared by milling the TiCl.sub.3 /AlCl.sub.3 with a particular phosphorous compound under special conditions and then treating with a liquid hydrocarbon and an ether and/or ester.

Abstract: A process for the preparation of homopolymers and copolymers of .alpha.-monoolefins by means of a Ziegler-Natta catalyst system comprising (1) a titanium-III component, which is prepared by subjecting (1.1) a titanium trichloride/aluminum trichloride compound (a) and (1.2) an ester (b) to a certain type of milling treatment in which (A) a vibratory ball mill providing a relatively high milling acceleration is used, (B) the mill is first charged with the titanium-containing compound (a) and, if appropriate, is run for a certain period, thereafter (C) the ester (b) is added at a certain rate while milling the charge, thereupon (D) the charge is kept at +15.degree. C. or above for a certain period, while continuing the milling, hereupon (E), if appropriate, the product obtained from (D) is milled further for a certain period at +5.degree. C. or below, then (F), if appropriate, but advantageously so, the product obtained from (D) or (E) is kept at +20.degree. C.

Abstract: According to this invention, there is provided a process for preparing polyolefins wherein olefins are polymerized or copolymerized using as catalyst a solid component and an organometallic compound, characterized in that said solid component is a substance obtained by the copulverization of:(1) a reaction product resulting from a heat reaction of magnesium oxide and aluminum trichloride,(2) a titanium compound and/or a vanadium compound, and(3) if desired, an organic halide.

Abstract: Polymerization catalyst preparation comprising milling magnesium metal, an organic halide and titanium tetrahalide in the presence of a triaryl phosphite and an aluminum trihalide but in the absence of a complexing diluent. The titanium catalyst component is activated with an organoaluminum activator producing a catalyst for olefin polymerization. In one embodiment, the titanium catalyst component is milled in the presence of magnesium oxide. In another embodiment, the milled titanium catalyst component is subjected to heat treatment.

Abstract: A process for the preparation of homopolymers and copolymers of .alpha.-monoolefins by polymerizing the monomer or monomers with a Ziegler catalyst system comprising (1) a titanium-containing catalyst component and (2) a relevant conventional organo-aluminum compound, (1.1) the catalyst component (1) having been prepared by (1.1.1) milling a titanium compound (I) of the formula TiCl.sub.3.z(AlCl.sub.3) or Cl.sub.m Ti(OB).sub.4-m, where z is from 0 to 0.5, m is from 0 to 3 and B is alkyl, together with (1.1.2) a magnesium alcoholate (II) and, if desired, (1.1.3) a metal chloride (III) of the formula AlCl.sub.3, ZnCl.sub.2 or MnCl.sub.2, to form a milled product (IV), in which polymerization process a catalyst component (1) is employed, in the preparation of which (1.2) the milled product (IV) obtained according to (1.1) is brought together, in an additional step (1.2.1), with (1.2.2) an alkanol (V) and (1.2.3) a liquid alkane (VI), to form a suspension (VII), and thereafter (1.

Abstract: A process for polymerizing an olefin which comprises causing the olefin to contact a catalyst comprising a combination of a component A which is a solid composition A obtained by causing:(a) a solid which contains a halogen-containing compound of a metal selected from the group consisting of magnesium, manganese, zinc and calcium,(b) a titanium compound,(c) a metal halide type Lewis acid which may be used as Friedel-Crafts catalyst, and(d) an organic compound selected from the group consisting of halohydrocarbons, halogen-containing organic acid esters and alcohols,to contact each other and a component B which is an organoaluminum compound.

Abstract: A solid transition metal compound is ground with an organo-sulphur compound which is a defined aromatic sulphone, sulphonamide or sulphide such as diphenylsulphone, N,N-diethyl-4-phenoxy benzenesulphonamide or phenoxathiin. A Lewis Acid such as titanium tetrachloride can be present during the grinding operation. Alternatively there may be present, during the grinding, an oxidizing agent capable of generating tetravalent titanium in the presence of titanium trichloride, for example carbon tetrachloride or gaseous oxygen. The grinding can be effected in a ball-mill or a vibrating mill. The materials may be added during the grinding and the temperature may be varied during the grinding. A liquid which is a solvent for the organo-sulphur compound or complexes thereof with aluminum chloride may be present during a part of the grinding.

Abstract: A supported titanium catalyst is produced by cogrinding, in combination, a magnesium halide, tetravalent titanium halide, organic acid ester, and an organic halogen compound. The resulting supported titanium catalyst, when employed as a titanium component with an organo aluminum catalyst component for the catalyst system in a process for stereoregular polymerization of .alpha.-olefins, produces high polymerization activity and unexpectedly high stereoregular polymer yielding ratios.