Abstract: A process for preparing an ethylene polymer by a two-stage polymerization of ethylene or ethylene and an .alpha.-olefin in an inert hydrocarbon at 50.degree.-100.degree. C. using a coordination polymerization catalyst containing a solid component and an organoaluminum compound, said solid component containing a transition metal compound, which process comprises:(a) in a first stage, producing 10-90% by weight based on the total polymer quantity of a polymer having a melt index in the range of 0.0001 to 0.5 g/10 min as measured according to ASTM D 1238-73, Condition E, using as said solid component a solid product obtained by supporting chromium trioxide or a compound which on calcining forms chromium oxide at least partially, on an inorganic oxide carrier followed by calcining, and using as said organoaluminum compound a compound of the general formula ##STR1## wherein R is a hydrocarbon radical having 1 to 18 carbon atoms and n is 2.ltoreq.n.ltoreq.

Abstract: An olefin polymerization supported catalyst comprising a support and the reaction product of a metallocene of Group 4b, 5b or 6b of the Periodic Table and an alumoxane, said reaction product formed in the presence of a support.

Abstract: Ziegler-Natta catalysts for polymerizing .alpha.-olefins are prepared by the addition of tetrakis(dialkylamide or diarylamide) derivatives of titanium, and a metal-containing reducing agent such as ethyl aluminum dichloride to a suitable support material such as magnesium chloride. Olefins are polymerized in the presence of these supported catalysts and an aluminum containing cocatalyst or activator such as triethylaluminum.

Abstract: A process for producing a catalyst component for polymerization of olefins which comprises contacting (a) a metal oxide with (b) a magnesium alkoxide, contacting the resulting contact product with (c) a halogen-containing compound, and finally contacting the resulting contact product with (d) a titanium compound.

Abstract: A process for producing a catalyst component for polymerization of olefins which comprises contacting (a) a metal oxide with (b) an organomagnesium compound represented by the formula RMgR' wherein R denotes a hydrocarbyl group and R' denotes a hydrocarbyl group or a halogen atom, contacting the resulting contacting product with (c) carbon dioxide, and further contacting the resulting contact product with (d) a titanium compound. Optionally, the carbon dioxide contacted contact product can be treated with the halogen-containing compound prior to contact with the titanium compound.

Abstract: A catalyst component for the polymerization of olefins which is prepared by contacting (1) a contact reaction product of (a) a metal oxide, (b) a dihydrocarbyl magnesium, and (c) a halogen-containing alcohol held with (d) an electron-donating compound, and (e) a titanium compound.

Abstract: A process for producing a catalyst component for polymerization of olefins which comprises contacting (a) a metal oxide with (b) a magnesium alkoxide, contacting the resulting contact product with (c) a halogen-containing compound, and finally contacting the resulting contact product with (d) a titanium compound.

Abstract: A process for producing a catalyst component for polymerization of olefins which comprises contacting (a) a metal oxide with (b) an organomagnesium compound represented by the formula RMgR' wherein R denotes a hydrocarbyl group and R' denotes a hydrocarbyl group or a halogen atom, contacting the resulting contacting product with (c) carbon dioxide, and further contacting the resulting contact product with (d) a titanium compound. Optionally, the carbon dioxide contacted product can be treated with the halogen-containing compound prior to contact with the titanium compound.

Abstract: Olefin polymerization catalysts are described which are based on solid inorganic oxides (such as silica) and polychromium complexes (such as octakis(.mu.-trimethylsilylmethyl) tetrachromium(II)). Linear low density ethylene homopolymers with specific short chain branching as well as polymerization processes to make these polymers using the specific catalyst described are also disclosed.

Abstract: Process of polymerizing a monomer charge including ethylene by (1) drying an inorganic oxide having surface hydroxyl groups to form a support that is substantially free of adsorbed water, (2) reacting the surface hydroxyl groups of the support with at least about 0.5 mol, per mol of surface hydroxyl groups, of at least one organometallic compound corresponding to the formula R.sub.x MR'.sub.y R".sub.z, wherein M is a metal of Group III of the periodic table, R is an alkyl group containing 1 to 12 carbon atoms, R' and R" are independently selected from the group consisting of H, Cl, and alkyl and alkoxy groups containing 1 to 12 carbon atoms, x has a value of 1 to 3, and y and z both represent values of 0 to 2, the sum of which is not greater than 3-x, (3) reacting the thus-treated support with at least about 0.001 molar proportion, per mol of organometallic compound, of a vanadium component consisting essentially of a mixture of about 10-90 mol percent of VOCl.sub.

Abstract: A first reactant selected from arylsilanol, hydrocarbyl amine, hydrocarbylphosphine oxide, and hydrocarbyloxyphosphite is combined with a second reactant selected from halogenated transition metal compound and an organometal compound to form a product which is catalytically active for olefin polymerization after optionally first having been deposited on a particulate diluent.

Abstract: A catalyst composition for polymerizing alpha-olefins is prepared by treating a carrier containing OH groups with an organomagnesium composition and contacting the thus-formed magnesium-containing carrier with a solution of a titanium (IV) alkoxide and a brominating and/or chlorinating agent. The adjustment of the molar ratio of the brominating and/or chlorinating agent to the titanium alkoxide yields catalysts which produce polymers of varying molecular weight distribution, as measured by the melt flow ratio (MFR) values. Also disclosed is a process for polymerizing alpha-olefins in the presence of the catalyst composition.

Abstract: Provided is an olefin-polymerization catalyst comprising the combination of the following components [I] and [II]:[I] a solid component obtained by intercontacting and reacting the following components (1) through (4):(1) a compound obtained by treating an oxide of an element of Groups II-IV in the Periodic Table with a compound represented by the general formula R.sup.1.sub.m Si(OR.sup.2).sub.n.sup.X.sub.4-m-n wherein R.sup.1 and R.sup.2 are each a hydrocarbon radical having 1 to 24 carbon atoms, a hydrocarbon radical containing oxygen, sulfur or nitrogen, or hydrogen, X is a halogen atom, m is 0.ltoreq.m<4 and n is 0.ltoreq.n.ltoreq.4, provided 0.ltoreq.m+n.ltoreq.4,(2) a reaction product obtained by the reaction of a magnesium halide and a compound represented by the general formula Me(OR.sup.3).sub.n.sup.X.sub.z-n wherein Me is an element of Groups I-VIII in the Periodic Table, with the limitation that silicon, titanium and vanadium are excluded, R.sup.

Abstract: A catalyst and method in which the catalyst is used in association with an aluminum cocatalyst in the polymerization and interpolymerization of 1-olefins. The catalyst is prepared by (1) reacting a mono- or polyfunctional phosphorus compound with silica, alumina or the like having surface hydroxyl groups, or a mixture thereof, in which the phosphorus compound reacts with these surface hydroxyl groups, followed by (2) reacting the product of this with a Group IIa (e.g. Mg) compound and further (3) reacting this product with a Group IVB, VB or VIB (e.g. Ti) compound. Alternatively, (1) is reacted with (3) and then with (2).

Abstract: A new polymerization catalyst system comprising an aluminum compound and a transition metal compound on an alumina-based aerogel support, a process for preparing the polymerization catalyst system and use of the catalyst system for polymerization and copolymerization of alpha-olefins are disclosed. A heat-activated alumina-based aerogel useful as a catalyst support and having a morphology by transmission electron microcopy comprising extremely thin folded film-like ribbons or plates and having a high BET surface area, high pore volume, and low bulk density is also disclosed.

Abstract: A suspension which comprises an inert liquid medium, a solid material, and a transition metal compound is dried using a spray-drying technique. The spray-drying is effected under conditions of temperature and pressure which are such as to cause evaporation of the liquid medium. The solid material is preferably in a finely-divided form. The solid material may consist essentially of a transition metal compound or may be a transition metal compound which is supported on a suitable solid inert matrix material. Alternatively, a suspension of a solid support material in a solution of a transition metal compound may be used. The dried solid is obtained as an agglomerate. The agglomerated solid can be mixed with an organic compound of a non-transition metal to give an olefin polymerization catalyst system.

Abstract: A catalyst, a method of preparing a catalyst and method of polymerizing olefins with the catalyst in which the catalyst is prepared by reacting a support with a Group IIA organometallic compound essentially free of aluminum alkyls and reacting this product with water or a hydrocarbyl alcohol, then reacting this product with, for example, titanium tetrachloride, followed if necessary by removing unreacted ingredients and finally activating by contacting with a cocatalyst in the absence of oxygen and moisture.

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: Olefin polymerization catalysts comprised of a supported adduct of a trialkyl-dialkylphosphato-titanate and chromium trioxide, processes for their preparation and polymerization processes employing the same.

Abstract: A method for producing .alpha.-olefin polymers is provided. This method provides products having superior properties such as higher bulk density and uniform particle form which is close to sphere, with such an extremely higher catalyst efficiency that ash-removal step can be omitted without fear of coloring.

Abstract: A process for producing polyethylene having a superior form and a narrower molecular weight distribution with a higher polymer yield is provided. In this process, a combination of a solid product (II) with an organoaluminum compound is used as a polymerization catalyst. This solid product is prepared by first reacting a trivalent metal halide with a divalent metal compound to form a solid product (I), which is then reacted with a halogen-containing transition metal compound and a halogen-free transition metal compound in the presence of a polysiloxane.

Abstract: A process for producing .alpha.-olefin polymers characterized by employing an organomagnesium compound in the preparation of a preactivated catalyst therefor is provided. The resulting polymers have particularly a higher rigidity in addition to various superior properties. The process comprises reacting a trivalent metal halide with a divalent metal compound to obtain a solid product (I); reacting this product with an organomagnesium compound, an electron donor (ED) and an electron acceptor (EA), once to 10 times, and at that time, using TiCl.sub.4 at least once as the (EA) to obtain a solid product (II); combining this product with an organoaluminum compound (OAl) and an (ED), and at that time, subjecting a combination of (II) and (OAl) or that of (II), (OAl) and (ED) to polymerization treatment with an .alpha.-olefin, and in the case of the former combination, further adding (ED), to obtain a preactivated catalyst; and polymerizing .alpha.-olefin(s) in the presence of this catalyst.

Abstract: Alpha-Olefins are polymerized in the presence of a catalyst which comprises (A) the reaction product of (1) a tetrahydrocarbyloxy zirconium compound such as tetraisopropoxy zirconium or a tetravalent hydrocarbyloxy zirconium halide such as triisopropoxy zirconium halide with (2) a chromium compound such as CrO.sub.3 ; (B) a solid catalyst support; (C) an organometallic activating agent or cocatalyst and (D) a trivalent or tetravelent titanium compound. The resultant polymers have a high molecular weight and a narrow molecular weight distribution.

Abstract: A process for producing high-quality .alpha.-olefin polymers with a higher yield in a long lasting stabilized manner even in the case of gas phase polymerization is provided. In the production process of .alpha.-olefin polymers which comprises reacting a trivalent metal halide with a divalent metal compound to obtain a solid product (I); reacting this product with at least one electron donor (ED) and at least one electron acceptor (EA), once to 10 times, and at that time, using TiCl.sub.4 at least once as the (EA) to obtain a solid product (II); combining this product with an organoaluminum compound (OAl) and an (ED) (these three being referred to as catalyst components), the improvement which comprises subjecting a part or the whole of the catalyst components to polymerization treatment with a small amount of an .alpha.-olefin, at least in the coexistence of the solid product (II) and (OAl), in the combination of the catalyst components to obtain a preactivated catalyst, and subjecting .alpha.

Abstract: A method for producing .alpha.-olefin polymers or copolymers by the use of an improved catalyst consisting of a combination of an organoaluminum compound with a specified solid product (III) which is produced by reacting a trivalent metal halide with a divalent metal hydroxide, oxide, carbonate, or a composite compound containing the foregoing compound(s) or a hydrate of a compound containing a divalent metal; reacting the resultant solid product (I) with a transition metal compound in the presence of an electron donor to produce a solid product (II); and further reacting said solid product (II) with a halogen-containing transition metal compound and a halogen-free transition metal compound.

Abstract: A method for producing .alpha.-olefin polymers which enables to control molecular weight distribution in a narrower range, with a higher yield and a higher crystallinity of products, is proposed. A catalyst used in said method is also proposed. The solid component of said catalyst is obtained by reacting a trivalent metal halide with a hydroxide, an oxide, a carbonate of a divalent metal, a double compound containing any of these compounds or a hydrate of a compound containing a divalent metal to produce a solid product (I); reacting one or more electron donors and one or more electron acceptors separately or simultaneously each in from one step 10 steps but by using TiCl.sub.4 as an acceptor at least in one step, with said solid product (I) to obtain a solid product (II); and then combining an organoaluminum compound and an electron donor with said solid product (II).

Abstract: Dual transition metal compounds containing titanium and chromium are prepared by reacting a hydrocarbyloxy titanium halide with CrO.sub.3. The compounds are useful in catalysts for the polymerization of .alpha.-olefins.

Abstract: An olefin is polymerized using a catalyst obtained by contacting (1) at least one of silicon or aluminum dioxide, (2) a compound of the formula ROH wherein R is a hydrocarbon radical having 1 to 20 carbon atoms, and (3) a substance obtained by supporting a titanium or a vanadium compound on a magnesium or manganese halide.

Abstract: A process for polymerizing alpha-olefins in the presence of a catalyst comprising two components. Component A is obtained by mixing a milled mixture of magnesium and particulate inorganic solid with an alcohol and then contacting the resultant product with a tetravalent halogenated titanium compound. Component B comprises a metallic hydride or an organometallic compound, e.g., an organoaluminum compound.

Abstract: A process for producing .alpha.-olefins is provided which comprises:milling (A) a trivalent metal halide together with (B) a divalent metal compound, in a specified ratio of (A) to (B), and reacting them to obtain a solid product (I);reacting with this product (I), (C) an electron donor and (D) an electron acceptor, (C) and (D) being respectively reacted once or more up to ten times, and TiCl.sub.4 being employed as the electron acceptor at least once, to obtain a solid product (II);combining with this product (II), (E) a trialkylaluminum and (G) a reaction product of an electron donor with an electron acceptor, and in this combination, subjecting a part or the whole of the catalyst components (product (II), (E) and (G)) to polymerization treatment by reacting (F) an .alpha.-olefin at least in the presence of the product (II) and trialkylaluminum, to obtain a preliminarily activated catalyst; andpolymerizing an .alpha.-olefin in the presence of this catalyst.

Abstract: A catalyst composition formed from selected organoaluminum compounds and a precursor composition of the formulaMg.sub.m Ti.sub.1 (OR).sub.n X.sub.p [ED].sub.q [Filler].sub.rwhereinED is a selected electron donor compoundR is a C.sub.1 to C.sub.14, aliphatic or aromatic hydrocarbon radical, or COR' wherein R' is a C.sub.1 to C.sub.14 aliphatic or aromatic hydrocarbon radical, X is Cl, Br, I, or mixtures thereof, Filler is an inert organic or inorganic compound, and, based on the total weight of such compositionm is .gtoreq.0.5 to .ltoreq.56n is 0 or 1p is .gtoreq.6 to .ltoreq.116q is .gtoreq.2 to .ltoreq.5r has a value such that the percent filler is from about 10 to about 95 weight percent based on the total weight of the precursor composition. A process for preparing such precursor composition by spray drying it from a slurry or solution in said electron donor compound, using atomization. A process for using said catalyst to readily prepare ethylene polymers having a density of about .gtoreq.0.91 to .ltoreq.

Abstract: Catalysts, especially for olefin polymerization are prepared by coating an aluminum compound on a selected high pore volume silica gel, and calcining the support at temperatures of from about 200.degree. to 2000.degree. F. The preferred catalyst is prepared with an inorganic support material as aforesaid, thereafter depositing an organophosphoryl chromium compound thereon, and activating the thus-treated support by heating in a non-reducing, preferably oxygen-containing, atmosphere at temperatures of from about 800.degree. to 2000.degree. F. The activated, supported catalyst composition may, but need not necessarily, be combined with a metallic and/or non-metallic reducing agent, to provide a catalyst system useful in the polymerization of 1-olefins.

Abstract: A method for producing .alpha.-olefin polymers is provided. According to this method, particularly the catalyst stability is improved, resulting in polymers having a higher crystallinity, a narrower range of molecular weight, improved shape of polymer particles with a higher yield per a solid product component and per a transition metal component of the catalyst. Said catalyst is obtained by reacting a trivalent metal halide with a hydroxide, an oxide, a carbonate of a divalent metal, a double compound containing any of these compounds or a hydrate of a compound containing a divalent metal to form a solid product (I); reacting said solid product with one or more electron donors and one or more electron acceptors separately or simultaneously each in one to 10 steps but using TiCl.sub.

Abstract: Polymerization of olefins in the presence of a catalyst system comprising a titanium-containing composition associated with silica and a cocatalyst comprising a metal hydride or organic metal compound derived from an element of Groups I-III of the Periodic Table.

Abstract: New, highly active catalysts for the polymerization of ethylene and mixtures of ethylene with higher alpha-olefins and/or diolefins, are disclosed. The catalysts are prepared by mixing (a) hydrides or organometallic compounds of metals belonging to Groups I, II or III of the Mendelycev Periodic Table with (b) the products obtained by contacting titanium compounds with activated anhydrous halides of magnesium or manganese, diluted with anhydrous compounds of metals belonging to Group III or IV of said Periodic Table, and which are different from either (a) or the titanium compound of (b).

Abstract: Alpha-olefins are polymerized in the presence of at least two independently supported catalysts, one of which is an inorganic halide supported titanium and/or vanadium Ziegler type catalyst and at least one other is inorganic oxide supported, chromium catalyst. This dual catalyst increases catalyst efficiency and/or provides more flexible control of the properties of the resulting polymers.

Abstract: This invention relates to the polymerization of .alpha.-olefins and to catalysts and cocatalysts for that purpose wherein the polymerization is carried out in the presence of a catalyst comprising an organometallic compound of a metal of Groups IA, IIA, IIB, IIIA, and IVA of the Periodic Table and a cocatalyst comprising the reaction product of a derivative of a transition metal of Groups IVB, VB, and VIB of the Periodic Table and a fluorinated reaction product having an atomic ratio of fluorine/divalent metal greater than 1, said fluorinated reaction product being formed by reacting a fluorinating agent with an oxygenated compound of a divalent metal at a temperature between about 150.degree. to 450.degree. C. for a time sufficient to form said reaction product. The invention also comprises the method of making the cocatalysts.

Abstract: A method for producing .alpha.-olefin polymers or copolymers by the use of an improved catalyst having a specific solid product combined with an organoaluminum compound is provided.The specific solid product (III) is prepared byreacting a trivalent metal halide with a specified divalent metal compound to obtain a solid product (I);reacting this product (I) with a transition metal compound of 4a group or 5a group of the Periodic Table in the presence of a polysiloxane to obtain a solid product (II); andfurther reacting this product (II) with at least two transition metal compounds of 4a group or 5a group, consisting of at least one member selected from the group (A) consisting of halogen-containing transition metal compounds of 4a group or 5a group, and at least one member selected from the group (B) consisting of halogen-free transition metal compounds of 4a group or 5a group to obtain the solid product (III).By employing this improved solid product (III) as a catalyst component, it is possible to produce .

Abstract: According to the invention, the method for applying a polymer coating onto the surface of a solid filler comprises deposition of a complex organometallic catalyst, containing a compound of a transition metal and an organic compound of a metal of the second or third groups of the periodic system, on the surface of the solid filler and liquid- or gas-phase polymerization of olefins at a temperature of 50.degree. to 170.degree. C. and a pressure of 1 to 60 atm on said catalyst deposited on the surface of the solid filler. The deposition is carried out in two stages. The first stage is gas-phase deposition of the first component of the catalyst, i.e. a compound of a transition metal, on the surface of the solid filler. The second stage is gas- or liquid-phase deposition of the second component of the catalyst, i.e. an organic compound of a metal of the second or third group of the periodic system.

Abstract: An alpha-olefin such as ethylene is polymerized in the presence of a catalyst system consisting of (1) an alkyl-halide, alkyl-derivative or hydride of a metal belonging to one of the first three groups of the periodic system and (2) the combination product of a transition metal chloride and titanium trichloride, supported on a previously chlorinated material such as chlorinated .gamma.-alumina having a high superficial area.

Abstract: Olefin polymerization catalysts are prepared by depositing an organophosphoryl chromium product and a non-volatile aluminum-containing product obtained from the reaction of an aluminum alkoxide and an aluminum salt of a lower aliphatic monocarboxylic acid on an inorganic support material and heating the support material in a non-reducing atmosphere at a temperature above about 300.degree. C. up to the decomposition temperature of the support material.

Abstract: There is disclosed a process for the stereoregular polymerization of alpha olefins or mixtures thereof with ethylene conducted in the presence of highly active and stereospecific new catalysts. The catalysts are obtained from the reaction of a particular Al-alkyl compound which is at least in part in the form of a complex and/or a substitution reaction product with an electron-donor compound free from ester groups of oxygenated organic and inorganic acids, with a supported component characterized by having surface area exceeding certain values or by showing a particular X-rays spectrum and which is obtained by contacting a halogenated Ti compound, preferably in the form of a complex with an electron-donor compound, with a support comprising a Mg or Mn dihalide in an active state. In the catalysts the ratio between the Ti compound expressed in Ti g-atoms and the g-moles of the electron donor compounds is lower than 0.3.

Abstract: .alpha.-olefins are polymerized with a catalyst prepared from (1) an inert support, (2) the reaction product of a tetravalent hydrocarbyloxy titanium halide such as di-n-butoxy titanium dichloride and hexavalent chromium oxide and (3) an organometal activating agent such as a tri alkyl aluminum.

Abstract: A catalyst composition consisting essentially of a reaction mixture of (A) at least one member selected from the group consisting of compounds of W, Mo, Re and Ta, (B) at least one member selected from the group consisting of organometallic compounds of elements of Groups IA, IIA, IIB and IIIA of the Deming Periodic Table, and (C) at least one member selected from the group consisting of compounds of V, Cr, Mn, and elements of Groups IVB and VIII of the Deming Periodic Table, has a very high activity in the ring-opening polymerization of norbornene derivatives having at least one polar substituent selected from the group consisting of ester groups, nitrile groups, amide groups, imide groups, carboxylic acid anhydride groups and halogens. The metal atom ratio of (C)/(A) is usually 0.001-50, and the molar ratio of (B)/(A) is usually 1-10.

Abstract: A process for the manufacture of olefin polymers by polymerizing .alpha.-monoolefins at relatively low temperatures and relatively low olefin pressures by means of a catalyst obtained from a silicate carrier (component a), an aluminum compound (component b) and a chromium compound (component c). The catalyst is obtained by (1) in a first stage, initially (1.1) charging a particular silicate carrier (component a) with (1.2) a mixture of (1.2.1) an aluminum salt or a mixture of an aluminum salt with up to 80 mole%, based on the salt mixture, of a nickel-II salt (component b) and (1.2.2) a chromium compound (component c), this compound being chromium trioxide or a compound which is converted to chromium trioxide under the conditions of stage (2), by treatment with a solution of the mixture (1.2), and (2), in a second stage then maintaining the product, obtained from stage (1), for a certain time at a high temperature in an anhydrous oxygen-containing gas stream.

Abstract: A random copolymer consisting essentially of 40 to 90 mole% of propylene and 60 to 10 mole% of 1-butene, and having (A) a boiling n-heptane-insoluble content of not more than 5% by weight based on the weight of the copolymer, (B) a boiling methyl acetate-soluble content of not more than 2% by weight based on the weight of the copolymer, (C) a melting point, determined by differential thermal analysis, of 40 to 140.degree. C., (D) an intrinsic viscosity, determined in decalin at 135.degree. C., of 0.5 to 6 dl/g, (E) an elongation at break, measured by JIS K6301, of at least 300%, (F) a tensile strength at break, measured by JIS K6301, of at least 50 kg/cm.sup.2, and (G) a haze, measured by JIS K6714, of not more than 40%.

Abstract: There is disclosed a process for the stereoregular polymerization of alpha olefins or mixtures thereof with ethylene, conducted in the presence of highly active and stereospecific new catalysts. The catalysts are obtained from the reaction of a particular Al-alkyl compound which is at least in part in the form of a complex and/or a substitution reaction product with an ester of an oxygenated organic or inorganic acid, with a supported component characterized by having surface area exceeding certain values or by showing a particular X-rays spectrum, and obtained by contacting a Ti halogenated compound, preferably in the form of a complex with an electron-donor compound, with a support comprising a Mg or Mn bihalide.In the catalysts the ratio between the Ti compound, expressed in Ti g-atoms, and the g moles of the ester and the electron-donor compound, when present, is lower than 0.3.

Abstract: A catalyst for the preparation of ethylene polymers having higher melt indexes comprises a silyl chromate deposited on a silica support containing both aluminum and titanium.

Abstract: An olefin polymerization catalyst is prepared by depositing the chromium (III) compound obtained from the reaction of a chromium (III) carboxylate with an aluminum alkoxide upon an inorganic support material and calcining the impregnated support material in a non-reducing atmosphere above 300.degree. C, up to the decomposition temperature of the support material to provide an activated catalyst.

Abstract: Alpha-olefins C.sub.3 -C.sub.6 are polymerized stereospecifically with the aid of catalysts obtained by mixing(a) a catalyst-forming component which is an addition and/or substitution product of an electron-donor compound (or a Lewis base) with an aluminum trialkyl, or an addition product of an electron-donor compound with an alkyl aluminum compound containing two or more Al - atoms bound to each other through an oxygen or nitrogen atom with(b) a supported catalyst-forming component which is the product obtained by contacting a titanium compound, preferably in the form of an addition product with an electron donor, with a carrier which is a mixture of an active anhydrous Mg or Mn dihalide and a solid organic material which is inert to all other components of the catalyst including the Mg or Mn dihalide carrier.