Abstract: Solid catalyst components for use in the polymerization of olefins and having improved activity and selectivity are prepared by:(a) halogenating a magnesium compound containing at least one aryloxy, alkyl carbonate or alkyloxy group with a first halide of tetravalent titanium and a first electron donor;(b.sub.1) contacting the resulting halogenated product with a second halide of tetravalent titanium; and(c) washing a resulting treated halogenated product with an inert hydrocarbon liquid, wherein a second electron donor is used in step (a) or step (b.sub.1) and in that the product of step (b.sub.1) is contacted in a step b.sub.2 with a third halide of tetravalent titanium at a temperature of 40.degree. to 140.degree. C. and thereafter the treated product is washed in step (c).

Abstract: Catalysts for the polymerization of alpha-olefins, which comprise the product of the reaction between:(a) a metallorganic compound of Al;(b) an electron-donor compound reactive towards MgCl.sub.2 but which is not completely complexed with AlEt.sub.3, at the equivalent point of a potentiometric titration under standard conditions;(c) a solid comprising a halogenated Ti compound and an electron-donor belonging to particular classes of compounds and being extractable with AlEt.sub.3 for at least 70% by mols from the solid, the surface area of which after extraction is higher than 20 m.sup.2 /g.The present invention refers to new supported components of catalysts for the polymerization of olefins CH.sub.2 .dbd.CHR, in which R is an alkyl with 1-4 carbon atoms or an aryl, and of mixtures of such olefins with each other and/or with ethylene, and to the catalysts obtained from such components.

Abstract: Catalysts for the preparation of copolymers of ethylene and/or alpha-olefins and optionally dienes, are obtained by reacting an Al-alkyl with a solid catalytic component comprising:(A) a magnesium compound containing at least an Mg-halogen bond;(B) a halogenated compound of at least partly trivalent Ti or V, containing at least a Ti-OR or V-OR bond, wherein the Mg/Ti(V), halogen/Ti(V), halogen/Mg and OR/Ti(V) atomic ratios are within determined ranges; and(C) an electron-donor compound.Elastomeric copolymers endowed with improved tension set values are obtained with said catalysts.

Abstract: A vanadium-based catalyst is treated with certain phosphorus-containing compounds as a means of narrowing and effectively regulating the molecular weight distribution of the polymers produced with the catalyst.

Abstract: A solid hydrocarbon-insoluble, alpha-olefin polymerization catalyst component with superior activity, stereospecificity and morphology characteristics comprises the product formed by (A) forming a solution of a magnesium-containing species from a magnesium carbonate or a magnesium carboxylate; (B) precipitating solid particles from such magnesium-containing solution by treatment with a transition metal halide and an organosilane; (C) reprecipitating such solid particles from a mixture containing a cyclic ether; and (D) treating the reprecipitated particles with a transition metal compound and an electron donor.

Abstract: An olefin polymerization catalyst system comprises a solid, hydrocarbon-insoluble, magnesium-containing, titanium-containing, electron donor-containing component; an alkyl aluminum compound; and organosilane compound selected from the group consisting of diisobutyldimethoxysilane, diisopropyldimethoxysilane, t-butyltrimethoxysilane and di-t-butyldimethoxysilane, and mixtures thereof.

Abstract: The invention concerns a procedure for manufacturing solid catalyst components for catalysts serving polymerization of alpha-olefines, having a solid carrier substance containing an organic or inorganic magnesium compound and treated with a titanium halide and optionally with an electron donor compound. The magnesium compound or the mixture of magnesium compound and electron donor compounds is sprayed in molten state into a chamber or volume which has been cooled to a temperature at which the catalyst component will solidify from the melt in the form of particles with generally spherical shape, without any substantial evaporation of solvents.

Abstract: A catalyst component for polymerization of olefin, comprising a contact product of a component (A) which is a solid component containing titanium having at least one OR.sup.1 group (where R.sup.1 represents a hydrocarbon residue) and magnesium and a halogen as the essential components; a component (B) which is an acid halide compound; a component (C) which is a compound having an OR.sup.2 group (where R.sup.2 represents a hydrocarbon residue or hydrogen atom); and a component (D) which is a halide compound of silicon. When an olefin is polymerized by use of this as the transition metal component of a Ziegler type catalyst, an olefin polymer with high activity and high I.I and excellent polymer properties can be obtained.

Abstract: A method for the production of a catalyst component for use in the polymerization of an olefin, which method comprises causing a magnesium-containing solid obtained by contact of (A) magnesium metal, (B) a halogenated hydrocarbon represented by the general formula, RX [wherein R stands for an alkyl, aryl, or cycloalkyl group having 1 to 20 carbon atoms and X for a halogen atom], and (C) a compound of the general formula, X.sub.n.sup.1 M(OR.sup.1).sub.m-n [wherein X.sup.1 stands for a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, M for a boron, carbon, silicon, aluminum, or phosphorus atom, R.sup.1 for a hydrocarbon group having 1 to 20 carbon atoms, and m for the valency of said atom M, providing that m>n.gtoreq.0 is satisfied], to contact (D) a halogen-containing alcohol and then contact (E) an electron donor type compound and (F) a titanium compound.

Abstract: A catalyst for olefin polymerization which comprises a combination of:Component which is a solid catalyst component A obtained by contacting a component (i) which is a solid component comprising titanium, magnesium and halogen as essential elements with a component (ii), which is a silicon compound represented by formula: R.sup.1 R.sup.2.sub.3-n Si(OR.sup.3).sub.n where R.sup.1 stands for a branched hydrocarbon radical, R.sup.2 stands for a hydrocarbon radical which is the same as or different from R.sup.1 and n stands for a number satisfying an equation: 1.ltoreq.n.ltoreq.3;Component B which is an organoaluminum compound; andComponent C which is a compound represented by a formula M(OR.sup.4).sub.x R.sup.5.sub.y X.sub.z in which M stands for an element selected from the group consisting of B, Al, C, Si, Sn, P, S, Cl, Br, I, Fe, Ti, V, Zr, Mg, Ca and Zn, R.sup.4 and R.sup.

Abstract: A method for the production of a catalyst component for use in the polymerization of an olefin, which method comprises causing a magnesium-containing solid obtained by contact of (A) magnesium metal, (B) a halogenated hydrocarbon represented by the general formula, RX, wherein R stands for an alkyl, aryl, or cycloalkyl group having 1 to 20 carbon atoms and X for a halogen atom, and (C) a compound of the general formula, X.sub.n.sup.1 M(OR.sup.1).sub.m-n, wherein X.sup.1 stands for a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, M for a boron, carbon, silicon, aluminum, or phosphorus atom, R.sup.1 for a hydrocarbon group having 1 to 20 carbon atoms, and m for the valency of said atom M, providing that m>n.gtoreq.0 is satisfied, to contact (D) a halogen-containing alcohol and then contact (E) a titanium compound.

Abstract: A method for the production of a catalyst carrier for use in the polymerization of an olefin, which method comprises causing a magnesium-containing solid obtained by contact of (A) magnesium metal, (B) a halogenated hydrocarbon represented by the general formula, RX wherein R stands for an alkyl, aryl, or cycloalkyl group having 1 to 20 carbon atoms and X for a halogen atom, and (C) a compound of the general formula, X.sub.n.sup.1 M(OR.sup.1).sub.m-n wherein X.sup.1 stands for a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms, M for a boron, carbon, silicon, aluminum, or phosphorus atom, R.sup.1 for a hydrocarbon group having 1 to 20 carbon atoms, and m for the valency of said atom M, providing that m>n.gtoreq.0 is satisfied, to contact (D) a halogen-containing alcohol.

Abstract: Crystalline magnesium olefin polymerization catalyst components capable of producing polymer with improved activity and morphological properties are disclosed and claimed. In particular, the components are prepared by reacting a crystalline alkoxy magnesium compound with a halide of tetravalent titanium.

Abstract: A catalyst system for use in olefinic polymerization and copolymerization is comprised of components (A), (B) and (C). The catalyst component (A) consisting essentially of titanium, magnesium, halogen, polycarboxylic acid esters and organic phosphorus compounds is a solid product, being prepared by mixing titanium tetrahalide and auxiliary precipitant with a homogeneous solution of magnesium halide in a solvent system consisting essentially of an organic epoxy compound and an organic phosphorus compound to form a solid product which is then treated with a polycarboxylic acid ester and titanium tetrahalide. Component (B) is an organic aluminum compound, and component (C) is an organic silicon compound. The catalyst system has a very high activity, and the resultant polymers have very high stereospecificity and good granular appearance.

Abstract: Olefin polymerization catalyst components having improved activity and morphological properties are disclosed and claimed. In particular, the components are prepared by reacting a carbonized magnesium alkoxide or aryloxide component with a halogenated tetravalent titanium component, a halohydrocarbon component and an electron donor.

Abstract: A process for polymerizing or copolymerizing ethylene comprises contacting ethylene or ethylene and at least one of .alpha.-olefins with a catalyst consisting essentially of a combination of (A) a solid catalyst component containing at least titanium, magnesium and chlorine, (B) an organoaluminum compound, and (C) an organic compound selected from the group consisting of a compound having P-O-C bond, a compound having B-O-C bond and a compound having C-O-R bond, at a temperature not lower than 125.degree. C. and under a pressure not lower than 200 kg/cm.sup.2.

Abstract: Syndiotactic 1,2-polybutadiene of high quality may be obtained in excellent yield by solution polymerization of butadiene-(1,3) in hydrocarbons, using organometallic mixed catalysts composed of trialkylaluminium, hydrocarbon-soluble chromium-III compounds and a dialkylphosphite corresponding to the formula ##STR1## wherein R denotes straight chained or branched C.sub.1 -C.sub.8 -alkyl andR.sub.1, R.sub.2 and R.sub.3 denote methyl or ethyl orR and R.sub.1 together form a methylene group.

Abstract: A process for producing catalyst ingredient for use in olefin polymerization which comprises contacting (A) a magnesium hydrocarbyloxide and (B) a silicon compound having hydrogen-silicon bonds in the presence of a hydrocarbon medium, contacting the thus obtained solid product (C) a halogenated titanium compound in the presence or absence of a hydrocarbon medium and then adding to contact (D) an electron donating compound.

Abstract: Ethane polymers are prepared by Phillips catalysis using (1) a supported catalyst which is laden with chromium, phosphorus and titanium and (2) a cocatalyst, (1) being obtained by a procedure in which (1.1) a catalyst intermediate laden with chromium, phosphorus and titanium is prepared from a silicate carrier, a selected chromium compound, a selected phosphorus compound and a selected titanium compound, and (1.2) the catalyst intermediate is then heated in an oxygen-containing gas stream. In the process, the supported catalyst (1) used is one which is obtained (using specific methods and substances in each case) by a procedure in which (1.1) in a first stage (1.1.1), a suspension is first prepared from (1.1.1.1) a finely divided silicate carrier and (1.1.1.2) an inert organic solvent, (1.1.2) a suspension is then prepared from (1.1.2.1) a finely divided chromium trioxide and (1.1.2.2) an inert organic solvent, (1.1.3) thereafter (1.1.3.1) the suspension resulting from (1.1.2) is combined with (1.1.3.

Abstract: A solid catalyst component which can produce .alpha.-olefin polymers having a high stereoregularity and a good powder fluidity, stably and with a good efficiency in gas phase polymerization, particularly in gas phase copolymerization, a catalyst for .alpha.-olefin polymerization using the above solid catalyst component and a process for producing the above catalyst component, are provided,which solid catalyst component is charcterized in that it contains titanium as an active ingredient and is in the form of hollow fine particles, andwhich process is characterized by adding a reaction product (I) of an organoaluminum compound (A) with an electron dnor (B.sub.1) to TiCl.sub.4 and reacting these under agitation in a baffle ratio of 0.35 or less with a power required for agitation of 2.50 KW/m.sup.3 or less at a temperature of 0.degree. to 70.degree. C. for a period of 1 to 10 hours and further reacting an electron donor (B.sub.

Abstract: Olefin polymerization catalyst components having improved activity and morphological properties are disclosed and claimed. In particular, the components are prepared by reacting a magnesium compound of the formula [Mg.sub.4 (OR).sub.6 (R'OH).sub.10 ]X where "X" is a counter ion having a total charge of -2 and R and R', which may be the same or different, are selected from alkyl groups of 1 to 4 carbon atoms, with a halogenated tetravalent titanium component, a halohydrocarbon component and an electron donor.

Abstract: An olefin polymerization catalyst comprising (a) a supported transition metal containing component comprising the support treated with at least one metallocene and at least one non-metallocene transition metal compound, and a cocatalyst comprising an alumoxane and an organometallic compound of a metal of Groups IA, IIA, IIB, or IIIA of the Periodic Table.

Abstract: A titamium containing catalyst component for olefin polymerizations which comprises contacting (a) a metal oxide, (b) a dihydrocarbyl magnesium, and (c) a hydrocarbyloxy group-containing compound with one another, contacting the thus obtained contact product with (d) a halogen-containing alcohol, and finally contacting the thus obtained contact product with (e) an electron donor compound and (f) a titanium compound.

Abstract: An aromatic hydrocarbon modified soluble mixed aluminum hydrocarbyl-Lewis base co-catalyst composition comprising (i) at least two different classes of aluminum hydrocarbyls the first being an aluminum hydrocarbyl halide, the second being an aluminum hydrocarbyl hydride and/or aluminum trialkyl and (ii) at least one Lewis base represented by the formula: ##STR1## wherein each Y can be --OR', --NR.sub.2 and R' with the proviso that at least two be --OR' or --NR.sub.2, Z is an alkylene radical forming a 5 or 6 membered ring with the carbonyldioxy group or Z is alkyl substituted alkylene group wherein the alkyl radical can have from 1 to 8 carbon atoms, R is an aryl, allyl or alkyl group having from 1 to 20 carbon atoms and R' is an alkyl, cycloalkyl, aryl or aralkyl radical having from 1 to 20 carbon atoms.The co-catalyst is employed with a titanium halide catalyst for the polymerization of olefins to obtain a advantageous balance of catalytic activity and polymer product stereoregularity.

Abstract: The present invention relates to catalysts which can be used for the polymerization and copolymerization of propylene with other alpha-olefins, characterized in that they comprise a support containing essentially magnesium chloride and possibly a chlorinated aluminium derivative, and occurring in the form of spheroidal particles having a mean diameter by mass comprised between 10 and 100 microns and a particle size distribution such that the ratio of the mean diameter by mass to the means diameter by number is less than or equal to 3, which support has been treated by an electron donor compound chosen from among the aromatic ethers and aromatic acid esters and which when impregnated with titanium tetrachloride comprises 0.5 to 3% of atoms of titanium per atom of magnesium, and process for utilizing the said catalyst.

Abstract: A process for preparing spherical particles of a compound with the general formula Mg(OR).sub.2-a (OR').sub.a is disclosed. In the process R is an alkyl group with from 2 to 8 carbon atoms, R' is an alkyl group with from 1 to 7 carbon atoms and a is a number of from 0 to 0.5. The process comprises preparing a homogeneous solution of a compound Mg(OR).sub.2 in an aliphatic alcohol with the general formula R'OH, spray-drying the solution at a temperature of from 15.degree. to 85.degree. C., suspending the spray-dried solid particles in an aliphatic alcohol with the formula ROH in which R is the same alkyl group as present in the said compound Mg(OR).sub.2, heating the suspension in order to remove an alcohol with the formula R'OH from the liquid phase by distillation and separating the solid particles from the liquid phase.

Abstract: A solid hydrocarbon-insoluble, alpha-olefin polymerization catalyst component with superior activity, stereospecificity and morphology characteristics, comprises the product formed by (a) complexing a magnesium alkyl composition with an organophosphoryl compound; (b) reacting the resulting stable complex with a compatible precipitation agent to form a solid component; and (c) reacting the resulting solid with a titanium (IV) compound and an electron donor compound in a suitable diluent.

Abstract: A process for preparing a catalyst component for the polymerization of olefins which comprises the steps of contacting (a) a magnesium dialkoxide soluble in an inert solvent, (b) a silicon compound having the hydrogen-silicon bond, and (c) an electron donor compound with one another in the presence of an inert solvent, and contacting the resulting reaction product with (d) a titanium compound.

Abstract: A catalyst component for the polymerization of olefins which is prepared by contacting a contact reaction product of (a) a metal oxide, (b) an organic magnesium compound, and (c) an alkoxy group-containing compound held in contact with (d) a titanium compound.

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: A cocatalyst employed with a titanium-containing catalyst, said titanium-containing catalyst comprising titanium atoms, halogen atoms, and an electron donor compound, said cocatalyst comprising(a) an organoaluminum compound represented by the formula R.sup.1 R.sup.2 R.sup.3 (wherein R.sup.1, R.sup.2, and R.sup.3 which may be the same or different, each denote a C.sub.1-20 alkyl, alkenyl, cycloalkyl, aryl, aralkyl, or alkoxy group, or a hydrogen atom;(b) an organoaluminum compound represented by the formula R.sub.3-n.sup.4 AlX.sub.n (wherein R.sup.4 denotes a C.sub.1-20 alkyl, alkenyl, cycloalkyl, aryl, aralkyl, or alkoxy group; X denotes a halogen atom; and n.gtoreq.1),(c) an electron donor compound containing a nitrogen atom, sulfur atom, oxygen atom, or phosphorus atom, and(d) an aromatic carboxylic acid ester.The catalyst is useful for the polymerization of olefins.

Abstract: A highly active catalyst suitable for the polymerization of olefins and its use are disclosed, said catalyst being prepared by(1) co-comminuting an aluminum halide; at least one electron donor; a Group IVB-VIB transition metal compound; and a support base selected from the group consisting of the Group IIA and IIIA salts and the salts of the multivalent metals of the first transition series with the exception of copper to produce a coground solid;(2) extracting said coground solid with an organic liquid; and(3) separating the solid from the liquid under such conditions that at least 5 weight percent of the aluminum in the coground solid is removed.

Abstract: A catalyst component for the polymerization of olefins which is prepared by contacting a reaction product of dihydrocarbyl magnesium and a halogen-containing alcohol held in contact with a titanium compound.

Abstract: A solid titanium containing catalyst component for use in olefin polymerization said component prepared by contacting a magnesium alkoxide, a halogenated hydrocarbon, an electron donor and a titanium compound with one another. In preferred embodiments, the magnesium alkoxide is first contacted with a magnesium halide. The solid titanium containing compound can be treated with an organoaluminum compound.

Abstract: Lewis base-bridged intermetallic compounds comprising the reaction product of a transition metal alkoxide with a reducing metal having a higher oxidation potential than the transition metal in the presence of a Lewis base and said reaction product being associated by coordinate covalent bridges formed from the Lewis base and composed of donor atoms selected from the group consisting of oxygen, nitrogen, sulfur and phosphorous; and catalyst components and systems for the polymerization of alpha olefins.

Abstract: A solid catalyst component for .alpha.-olefin polymerization which, when produced, causes any troubles due to its small particle size and when used, yields a spherical polymer of a suitably less particle size and a high bulk density with a slightest quantity of atactic polymer and affording a very good dispersibility of powdery additives therein in spite of its narrow particle size distribution, and a process for producing the same, are provided, which solid catalyst component comprises Ti and Cl as active ingredients, having an average particle diameter of 2 to 10.mu., a specific surface area of 100 m.sup.2 /g or more and a diffraction line corresponding to a distance between lattices of 4.80 to 5.10 .ANG. by way of X-ray diffraction; and which process is characterized in that when TiCl.sub.4 is reduced with a reducing agent comprising an organoaluminum compound to produce a solid intermediate, there is employed an agitation intensity defined by definite values of agitation power and baffle ratio.

Abstract: New catalysts which can be used for the polymerization and copolymerization of ethylene, comprising a support consisting basically of magnesium chloride on which is deposited by precipitation a vanadium compound, obtained by bringing a vanadium compound in which the vanadium is at one of the two maximum valencies 4 and 5 in contact with a support consisting basically of magnesium chloride and optionally of aluminium chloride and comprising products with an Mg--C bond.

Abstract: A catalyst system especially suited for polymerizing alpha-olefins in the gas-phase to polymers containing essentially no active chloride comprises (A) a titanium-containing component supported on a hydrocarbon-insoluble magnesium-containing compound in combination with an electron donor compound and (B) a co-catalyst comprising (a) at least one trialkylaluminum compound (b) an aromatic acid ester and (c) an unhindered secondary amine, optionally reacted with a dialkylaluminum hydride, in substantial absence of compounds containing an Al-Cl bond.

Abstract: A process for polymerizing olefins in the presence of a catalyst composed of:(A) a catalyst component obtained by contacting with one another,(a) a magnesium alkoxide,(b) a silicon compound having a hydrogen-silicon bond,(c) an electron donor compound, and(d) a titanium compound(B) an organic compound of a metal of Groups I and III of the Periodic Table, and(C) an organo silicon compound represented by the formula R.sub.q.sup.9 SiX.sub.g.sup.2 (OR.sup.10).sub.k wherein R.sup.9 and R.sup.10 are the same or different hydrocarbon groups, X.sub.2 is a halogen atom, 0.ltoreq.q<4, 0.ltoreq.g<4, 0<k.ltoreq.4, and q+g+k=4.

Abstract: A method of producing a polymerization catalyst component suitable for use in the polymerization of alpha-olefins, which method comprises forming an active component by co-comminuting an inorganic Lewis acid, a first organic electron donor, a support base selected from the group consisting of the Group IIA and IIIA salts and the salts of the multivalent metals of the first transition series with the exception of copper, and a polymerization active tri-, tetra-, or penta- valent transition metal compound of a Group IVB-VIB metal, and heating the active component in an inert hydrocarbon solvent to produce the polymerization catalyst component. The active component can be heated in the inert hydrocarbon solvent in the presence of an additional polymerization active tri-, tetra-, or penta- valent transition metal compound of a group IVB-VIB metal. In addition, a second organic electron donor may be incorporated in the active component.

Abstract: Novel titanium compounds or complexes are prepared by reacting a titanium compound such as titanium tetraisopropoxide with a mixture comprising (a) at least one compound containing at least one aromatic hydroxyl group and (b) at least one compound having at least one aliphatic hydroxyl group. These compounds and/or complexes are useful as the transition metal component in Ziegler-Natta catalysts.

Abstract: A titanium halide containing catalyst component for polymerization of olefins which is prepared by reacting a magnesium hydrocarbyloxide with a silicon compound having at least one hydrogen-silicon bond, contacting the reaction product with an electron donor compound, contacting the resulting contact product two or more times with a titanium halide and between one of the multiple titanium halide contacts, contacting the titanium halide contacted solid with a halide of an element selected from the group consisting of elements of Groups IIIa, IVa, and Va of the Periodic Table of elements.

Abstract: A titanium halide containing catalyst component for polymerization of olefins which is prepared by reacting a magnesium hydrocarbyloxide with a silicon compound having a hydrogen-silicon bond, contacting the reaction product with an electron donor compound, contacting the resulting contact product two or more times with a titanium halide and between one of the multiple titanium halide contacts, contacting the titanium halide contacted solid with a halogenated hydrocarbon.

Abstract: A process is disclosed for preparing a titanium catalyst component useful for homopolymerizing 1-alkenes and for copolymerizing 1-alkenes with each other and/or with ethylene, consisting essentially in grinding a titanium halide compound/electron-donor complex with a magnesium aluminum halide obtained by precipitation from an organic solvent.In the process the ground product is first washed with a washing liquid containing a solvent for the aluminum halide/electron-donor complex which forms during the grinding process and by preference at least one alcohol, the molar ratio between alcohol and titanium in the ground product ranging between 50:1 and 1:20, and then the washed product is exposed to a liquid titanium halide compound.With this procedure, it is possible to obtain a titanium component which imparts to the polymerization catalyst an excellent stereospecificity along with a very high activity, and with which it is possible to obtain polymers, e.g.

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: An intermetallic compound comprising the reaction product of a transition metal and a reducing metal of a higher oxidation potential than the transition metal obtained by the reaction of a polymeric transition metal oxide alkoxide and the reducing metal in the presence of a mono- or dialkyl phosphate or mixtures thereof in which each alkyl contains up to 10 carbon atoms; and catalyst components and systems for the polymerization of alpha olefins.

Abstract: A highly active and stereoselective olefin polymerization catalyst component is obtained by halogenating a magnesium compound of the formula MgR'R" wherein R' is an alkoxide or aryloxide group and R" is an alkoxide or aryloxide group or halogen, with a halide of tetravalent titanium in the presence of a halohydrocarbon, and contacting the halogenated product with an acid halide and a tetravalent titanium compound.

Abstract: A process for producing .alpha.-olefin polymers having high crystallinity and good particle form, with a high yield is provided. The polymerization therefor is carried out in the presence of a preactivated catalyst suitable particularly to gas phase polymerization or gas phase polymerization following slurry or bulk polymerization.The catalyst is prepared by reacting a reduction solid prepared by reducing TiCl.sub.4 with an organoaluminum compound, with an electron donor and an electron acceptor to obtain a solid product, andcombining this solid product with an organoaluminum compound, an .alpha.-olefin and a reaction product of an organoaluminum compound with an electron donor.

Abstract: Catalyst components for the stereoregular polymerization of alpha-olefins, comprising a Ti halide and an electron-donor compound supported on an anhydrous magnesium dihalide and obtained by means of non-extractive treatments, with liquids having a dielectric constant at 20.degree. C. equal to or higher than 2, of compositions comprising an anhydrous Mg dihalide, the crystallites of which have an average size lower than 300 .ANG..The present invention refers to new catalyst components and the catalysts obtained therefrom for the polymerization of alpha-olefins Ch.sub.2 .dbd.CHR, wherein R is an alkyl radical with 1-4 C atoms or an aryl radical, and of mixtures of said alpha-olefins with minor amounts of ethylene.

Abstract: A comminuted, supported polymerization catalyst for alpha-olefins comprises (A) an organoaluminum compound and (B) a solid titanium-containing component formed by at least one halogen-containing compound of titanium(IV); (b) at least one electron donor; and (c) at least one hydrocarbon-insoluble magnesium-containing compound; and (2) retreating such comminuted product with (a) at least one halogen-containing compound of titanium(IV); and (b) a mixture containing ethylbenzoate and a substituted alkyl aromatic acid ester in which the substituent group has a negative Hammett constant; and optionally, at least one chlorocarbon and/or at least one haloalkylchlorosilane.