Abstract: The invention concerns a process for manufacturing low density linear polyethylene by copolymerizing ethylene and 1-butene, comprising the steps of:(a) dimerizing ethylene to 1-butene in the presence of a soluble catalyst comprising: an alkyl titanate, an aluminum compound of formula AlR.sub.3 or AlR.sub.2 H, wherein R is a hydrocarbyl radical, and an ether;(b) contacting at least a portion of the product obtained in step (a) with an inorganic compound, at least partly insoluble;(c) contacting the insoluble mixture obtained in step (b) with an halogenated aluminum compound of formula Al.sub.2 R'.sub.6-n X.sub.n, wherein R' is a hydrocarbyl radical, X a halogen atom, and n a number from 3 to 6, when an halogenated aluminum compound is not already present in said mixture;(d) using the resultant product, containing at least one inorganic carrier, at least one halogenated aluminum compound and at least one titanium compound, as catalyst in the polymerization reactor.

Abstract: Ethylene polymers are obtained in enhanced yield in a process for homopolymerizing ethylene or copolymerizing ethylene with an alpha-olefin having 3 to 8 carbon atoms employing a catalyst system comprising (a) a solid titanium (III)-containing precursor, and (b) an organoaluminum activator, by heating the titanium (III)-containing precursor, prior to activating with the organoaluminum activator, at a temperature of 140.degree.-200.degree. C. for a sufficient time to reduce the electron donor level of the precursor from at least about 20 percent to about 80 percent over the electron donor level achieved by drying to constant weight.

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: Disclosed is a catalyst component for polymerization of an olefin, which consists essentially of a contact reaction product of (A) a solid composition obtained by mixing and contacting a precipitating agent with a contact reaction product between a magnesium dihalide and a titanium tetraalkoxide and/or a polymer thereof, the addition of the precipitating agent being carried out with stirring at a stirring intensity lower than a level (2nf) two times the floatation limit stirring intensity (nf) of the reaction system, with (B) a liquid titanium compound and/or a halogen compound of silicon.This catalyst component has a high activity and provides a polymer in which the particle size is relatively large and the particle size distribution is sharply controlled.

Abstract: An olefin is polymerized by using a catalyst consisting essentially of (A) a solid catalyst component containing a magnesium halide and a titanium chloride, (B) an organic aluminum compound, and (C) an ether compound represented by the formula: R.sup.1 R.sup.2 R.sup.3 C(OR.sup.4), R.sup.1 R.sup.2 C(OR.sup.4).sub.2 or R.sup.1 C(OR.sup.4).sub.3. The catalyst has high catalytic activity and high stereoregularity as well as good activity endurance and is especially suitable for production of block copolymers.

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: A catalyst composition for polymerizing alpha-olefins is prepared by treating a carrier containing OH groups with a liquid solution containing an excess of an organomagnesium composition with respect to the OH groups and contacting the thus-formed magnesium-containing carrier with a solution of at least one transition metal compound. Prior to contacting the magnesium-containing carrier with the transition metal compound, most of the liquid must be removed therefrom, so that it comprises not more than about 6% of the liquid. The amount of the transition metal compound is such that the molar ratio of the transition metal to magnesium in the reaction mixture is about 0.3 to about 0.9. Also disclosed is a process for polymerizing alpha-olefins in the presence of the catalyst of the invention.

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: In a process for producing olefin polymers or copolymers which comprises polymerizing olefins or copolymerizing olefins with each other or with dienes in the presence of [A] a solid titanium catalyst component containing magnesium, titanium and halogen as essential ingredients and [B] an organometallic compound of a metal selected from the group consisting of metals of Groups I to III of the periodic table; the improvement wherein said catalyst component [A] is obtained by contacting (i) a magnesium compound in the liquid state with (ii) a titanium compound in the liquid state to form a solid product or first preparing a liquid mixture of the magnesium compound (i) and the titanium compound (ii) and then forming a solid product therefrom, said reaction of forming the solid product being carried out in the presence of at least one electron donor (iii) selected from the group consisting of aliphatic carboxylic acids with 1 to 6 carbon atoms, aryloxy group-containing alcohols, alkylene glycol diethers, aluminum

Abstract: A catalyst comprising:(A) a solid catalyst component containing a tri-valent titanium compound, which is obtained by reducing a titanium compound represented by the general formula Ti(OR.sup.1).sub.n X.sub.4-n (wherein R.sup.1 is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen atom and n is a number satisfying 0<n.ltoreq.4) with an organo magnesium compound in the presence of an organo silicon compound having Si--O bonds and then treating the resulting solid product with an ester compound and a mixture of an ether compound and titanium tetrachloride,(B) an organo aluminum compound, and(C) a silicon compound having Si--OR.sup.2 bonds (wherein R.sup.2 is a hydrocarbon group having 1 to 20 carbon atoms) and/or an organic carboxylic acid ester,and a process for producing .alpha.-olefin polymers using the same.

Abstract: A supported solid catalyst composition for polymerizing alpha-olefins is prepared by treating a carrier with a transition metal compound. The carrier utilized in the synthesis must have such an average pore diameter that the resulting catalyst composition has an average pore diameter of at least about 170 Angstroms. The catalyst composition has higher productivity than similar catalyst compositions of lower average pore diameter, and it produces polymers of lower density and higher melt and high load melt indexes than such similar catalyst compositions of lower average pore diameter. Also disclosed is a process for polymerizing alpha-olefins in the presence of the catalyst of the invention.

Abstract: A catalyst composition for polymerizing alpha-olefins is prepared by treating a carrier containing OH groups with a liquid solution containing an excess of an organomagnesium composition with respect to the OH groups and contacting the thus-formed magnesium-containing carrier with a hydrocarbyl alcohol and at least one transition metal compound. Prior to contacting the magnesium-containing carrier with the alcohol, most of the liquid must be removed therefrom, so that it comprises not more than about 6% of the liquid. The amount of the transition metal compound is such that the molar ratio thereof to magnesium in the reaction mixture is about 0.3 to about 0.9. Also disclosed is a process for polymerizing alpha-olefins in the presence of the catalyst of the invention.

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

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: A catalyst component for polymerization of olefins, which consists essentially of a particulate contact reaction product of an average particle size of 10 to 100 microns, obtained by contacting the surfaces of particles of a product of contact reaction with a magnesium halide and an alkoxy group-containing compound of a metal of Group I, II, III or IV of the Periodic Table with an alcohol compound and contacting the resulting contact reaction product with a liquid titanium halide. This catalyst component has a high activity and provides a polymer having a relatively large particle size and a narrow particle size distribution.

Abstract: A catalyst is formed by reacting, in a hydrocarbon medium, a trialkylaluminum with a mixture of an alkyl titanate with an ether. The activity and the selectivity are improved when adding the trialkylaluminum to a pre-formed mixture of alkyl titanate with ether.

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: Composition comprising a transition metal component and magnesium carboxylate prepared by reacting a solution of hydrocarbyl magnesium compound with carbon dioxide to precipitate a magnesium carboxylate and reacting magnesium carboxylate with transition metal component.

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 vanadium containing catalyst component useful for polymerizing olefins to polyolefins having a high molecular weight and broad molecular weight distribution comprising polymerizing the olefins in the presence of a catalyst comprising (a) a vanadium containing catalyst component obtained by contacting an inert support material with an organoaluminum compound, a halogenating agent and a vanadium compound, and (b) an aluminum alkyl cocatalyst.

Abstract: A process for producing .alpha.-olefin polymers is proposed wherein the catalyst prepared and used therein is superior in the shelf stability and heat stability. The process comprises reacting TiCl.sub.4 with a reaction product (I) of an organoaluminum compound with an electron donor to obtain a solid product (II), which is then subjected to polymerization treatment with an .alpha.-olefin, and further reacted with an electron donor and an electron acceptor to obtain a solid product (III), which is then combined with an organoaluminum compound, to obtain a catalyst, in the presence of which .alpha.-olefin(s) are polymerized. The catalyst can be further preactivated with an .alpha.-olefin in advance of its use for the polymerization.

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: 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 ortho disubstituted hindered aromatic acid ester; (b) reacting the resulting 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 vanadium-containing catalyst component useful for the polymerization of olefins to polyolefins having a high molecular weight and a broad molecular weight distribution comprising polymerizing the polyolefins in the presence of a catalyst comprising (A) a vanadium-containing catalyst component obtained by contacting an inert support material with a dihydrocarbyl magnesium compound, optionally an oxygen-containing compound, a vanadium compound, a Group III metal halide, and (B) an aluminum alkyl cocatalyst.

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 vanadium containing catalyst component useful for polymerizing olefins to polyolefins having a high molecular weight and broad molecular weight distribution comprising polymerizing the olefins in the presence of a catalyst comprising (a) a vanadium containing catalyst component obtained by contacting an inert support material with an organoaluminum compound, an acyl halide and a vanadium compound, and (b) an aluminum alkyl cocatalyst.

Abstract: A vanadium-containing catalyst component useful for the polymerization of olefins to polyolefins having a high molecular weight and a broad molecular weight distribution comprising polymerizing the polyolefins in the presence of a catalyst comprising (A) a vanadium-containing catalyst component obtained by contacting an inert support material with a dihydrocarbyl magnesium compound, optionally an oxygen-containing compound, a vanadium compound, a Group III metal halide, and (B) an aluminum alkyl cocatalyst.

Abstract: A catalyst composition for polymerizing alpha-olefins in a gas phase continuous process is prepared by combining a catalyst precursor with a catalyst activator in such proportions that the polymer product comprises about 9.times.10.sup.-7 to about 18.times.10.sup.-7 gram-moles of the activator per gram of the polymer produced. The use of the activator in these proportions lowers the partial pressure of the monomers used in the process without sacrificing quality of the product. The catalyst precursor is prepared by reacting a carrier having OH groups with a stoichiometric excess, with respect to the OH groups, of an organomagnesium composition, and subsequently reacting the product with a transition metal compound.

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: In a polymerization of alpha mono-olefins by means of certain supported coordination catalysts systems which comprise (a) a procatalyst, (b) a cocatalyst, and (c) a selectivity control agent, wherein (a) is a highly active solid composition which comprises magnesium chloride, titanium tetrachloride and an electron donor; and (b) is an aluminum trialkyl; the selectivity control agent comprises a strong selectivity control agent and a weak selectivity control agent.

Abstract: A catalyst component for polymerization of .alpha.-olefins is produced by causing mutual contact of:(A) a magnesium halide containing solid;(B) an electron donating compound, having the structural site as represented by the formula show below in its molecule: ##STR1## and (C) a titanium halide. The catalyst thus produced has high polymerization activity and is capable of producing polymers having excellent stereoregularity.

Abstract: A process for preparation of a component of a catalyst for polymerization of .alpha.-olefins is disclosed. The process comprises the steps of heating a titanium containing component during and/or after milling operation thereof. The titanium-containing catalyst component thus produced makes it possible to produce polymers having a high stereoregularity in high specific yield.

Abstract: A vanadium dichloride-ether complex is carried on a porous support. This complex can be produced by either forming VCl.sub.2 and thereafter complexing the material with an ether or forming an ether complex with VCl.sub.4 or VCl.sub.3 and thereafter reducing the vanadium compound to VCl.sub.2. It is also possible to carry out the complexing reaction and the reduction essentially simultaneously. The resulting catalyst in combination with a cocatalyst is capable of giving high activity in olefin polymerization and demonstrates good sensitivity to molecular weight control agents, thus allowing the production of a broad spectrum of polymers so far as molecular weight is concerned.

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 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: 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: Isotactic index improvement is achieved for C.sub.3 and higher alpha olefins in systems containing a catalyst component comprising titanium supported on a magnesium halide support. The titanium component is formed by copulverizing the magnesium halide with one or more electron donors followed by treatment with liquid titanium halide. The improvement is achieved by using a dialkylaluminoxane component with the trialkylaluminum co-catalyst normally used. In slurry polymerizations, the isotactic index of the polymer has been improved.

Abstract: A titanium-containing catalyst component for polymerization of olefins which is prepared by reacting a magnesium hydrocarbyl oxide with a silicon compound having a hydrogen-silicon bond, contacting the reaction product with an electron donor compound, contacting the resulting contact product with an organoaluminum compound and further with a titanium compound.

Abstract: A solid catalyst component for olefin polymerization comprising a hydrocarbon-insoluble product(III) obtained by reacting(A) a silicon compound selected from the group consisting of(1) silicon compounds represented by the general formula R.sup.1.sub.a R.sup.2.sub.b R.sup.3.sub.c Si, wherein R.sup.1, R.sup.2 and R.sup.3 are each an alkyl, cycloalkyl, aralkyl, aryl, alkoxy, aryloxy, or hydroxyl group or a halogen or hydrogen atom; and a, b and c are numbers defined by the formulas 0.ltoreq.a,b,c,.ltoreq.

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: 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.