Abstract: A process for preparing conjugated diene polymers by polymerizing conjugated diene monomers in the presence of a catalyst composition that is formed by combining an iron-containing compound, a hydrogen phosphite, and an organoaluminum compound.

Abstract: Complexes of certain transition metals with certain phosphorous-nitrogen bidentate ligands are part of all of catalyst systems for the polymerization of ethylene. Under certain polymerization conditions novel, highly branched, homopolyethylenes may be produced.

Abstract: The present invention is directed to processes of polymerization of olefins and copolymerization of olefins and functionalized olefins in the presence of certain late transition metal bidentate salicylaldimine chelates represented by the formula: wherein each of the symbols R, R1, R2, R3, R4, R5, R6, L, M, A, X and z are defined within the specification herein below.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients including an iron-containing compound, a hydrogen phosphite, and a mixture of two or more organoaluminum compounds. This catalyst composition is particularly useful for polymerizing conjugated dienes. When this catalyst composition is used to polymerize 1,3-butadiene into syndiotactic 1,2-polybutadiene the ratio of the organoaluminum compounds can be adjusted to vary the melting temperature and molecular weight of the polymer product.

Abstract: A method for making a polymer comprising the step of synthesizing a polymer by employing a chain transfer agent having the formula (II) where X and Y are independently selected from oxygen, sulfur, and fully-substituted nitrogen where R1 and R2 are independently selected from hydrogen, halogen, or an organic group, with the proviso that at least one of R1 or R2 be hydrogen or halogen, R3 is an organic group R4 and R5 are independently selected organic groups, with the proviso that R3 is not hydrogen.

Abstract: A catalyst composition comprising (a) an iron-containing compound, (b) an organomagnesium compound and (c) a dihydrocarbyl hydrogen phosphite is disclosed for polymerizing 1,3-butadiene into syndiotactic 1,2-polybutadiene. The use of the catalyst composition of this disclosure avoids the use of environmentally detrimental components such as carbon disulfide and halogenated solvents. The melting temperature of the syndiotactic 1,2-polybutadiene can be varied from about 100 to about 190° C. by variations in the catalyst components and the component ratios. The ability to vary the melting temperature with a single catalyst composition is very desirable. The syndiotactic 1,2-polybutadiene can be used as a plastic or as an additive for rubber compositions wherein it can crosslink with conventional rubbers using conventional crosslinking agents.

Abstract: A catalyst and process of polymerizing olefins using it are described, the catalyst comprising a cocatalyst and a metal complex preferably of the formulas 4-9, wherein M is a group 4 metal, Z is a boron atom, and T is one of

Abstract: There are provided (i) a catalyst component (C), (ii) an olefin polymerization catalyst, and (iii) a process for producing an olefin polymer. The catalyst being obtained by contacting a solid catalyst component (A), an organoaluminum compound (B) and the catalyst component (C) of an organosilicon compound represented by the following formula (1), wherein n is 1 or 2, R1 to and R6 are independently of one another a hydrogen or halogen atom or a hydrocarbon group, or may be bonded with one another to form a ring, R7 is a hydrocarbon group, and when n is 2, two R1s, R2s, R3s, R4s, R5s and R6s may be the same or different.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients including (a) a molybdenum-containing compound, (b) a hydrogen phosphite, and (c) a blend of two or more sterically distinct organoaluminum compounds. This catalyst composition is particularly useful for polymerizing conjugated dienes. When this catalyst composition is used to polymerize 1,3-butadiene into syndiotactic 1,2-polybutadiene, the ratio of the organoaluminum compounds can be adjusted to vary the melting temperature and molecular weight of the polymer product.

Abstract: A method for making a polymer comprising the step of synthesizing a polymer by employing a chain transfer agent having the formula (II) 1

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients including an iron-containing compound, a hydrogen phosphite, and a mixture of two or more organoaluminum compounds. This catalyst composition is particularly useful for polymerizing conjugated dienes. When this catalyst composition is used to polymerize 1,3-butadiene into syndiotactic 1,2-polybutadiene the ratio of the organoaluminum compounds can be adjusted to vary the melting temperature and molecular weight of the polymer product.

Abstract: The present invention provides a process for preparing a branched diene elastomer having a high proporation of starred chains comprising anionically polymerizing at least one conjugated diene monomer having 4 to 12 carbons in a polymerization medium comprising a hydrocarbon solvent, such as cyclohexane, and an organometallic initiator, such as n-butyllithium, wherein tris-(2,4-di-tert-butylphenyl)phosphite is added to the polymerization medium as a starring agent during or at the end of polymerization in an amount such that the molar ratio of the starring agent to the initiator is between 0.1 and 1.5, preferably between 0.2 and 0.5. The process produces a branched diene elastomer having a high proportion of starred chains. The elastomer can be a homopolymer, such as polybutadiene or polyisoprene or a copolymer, such as polystyrene/polybutadiene.

Abstract: A novel process for the polymerization of olefins is provided. The process involves contacting at least one olefin with at least one metallocene catalyst in the presence of a specified compound that results in the production of polymeric products having a narrower molecular weight distribution. Also provided is a process for narrowing the molecular weight distribution of a polyolefin comprising contacting an olefin, at least one metallocene catalyst and a compound specified herein. Further provided are novel polyolefins, and films and articles produced therefrom.

Abstract: A process for preparing blends of syndiotactic 1,2-polybutadiene and rubbery elastomers comprising the steps of (1) providing a mixture of high cis-1,4-polybutadiene rubber cement and 1,3-butadiene monomer, and (2) combining (a) an iron-containing compound, (b) a hydrogen phosphite, and (c) an organoaluminum compound to form a catalyst composition outside the presence of the mixture of rubber cement and monomer, and (3) adding the catalyst composition to the mixture and thereby polymerizing the 1,3-butadiene monomer into syndiotactic 1,2-polybutadiene within the rubber cement.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients comprising a iron-containing compound, an organomagnesium compound, and a silyl phosphonate.

Abstract: Conjugated diolefins, optionally in combination with other unsaturated compounds which may be copolymerized with the diolefins, are polymerized by performing the polymerization of the diolefins in the presence of catalysts based on cobalt compounds, organoaluminum compounds and modifiers in the presence of aromatic vinyl compounds at temperatures of −30° C. to +80° C. By means of the process according to the invention, it is possible straightforwardly to produce solutions of polydiolefins, such as polybutadiene, having different 1,2 unit contents in aromatic vinyl compounds, which solutions may then, for example, be further processed to yield ABS or HIPS.

Abstract: Oily hyperbranched polymers derived from ethylene, propylene, butene and/or a C5-C24 &agr;-olefin, and a method for their synthesis, are disclosed. The polymers have non-regular microstructures and are characterized by a ratio ()of methyl hydrogens centered around 0.85 ppm on the 1H-NMR spectra of the polymers relative to total aliphatic hydrogens of from about 0.40 to about 0.65 for polymers derived from ethylene or butene, and a ratio ()of from greater than 0.50 to about 0.65 for polymers derived from propylene. A method for grafting hyperbranched polymers derived from ethylene, propylene, butene and/or a C5-C24 &agr;-olefin onto aromatic rings in organic molecules and polymers, and the resulting grafted materials, are also disclosed. The hyperbranched polymers and grafted materials are useful, for example, as lubricants and lubricant additives.

Abstract: A catalyst composition comprising (a) an iron-containing compound, (b) an organomagnesium compound and (c) a dihydrocarbyl hydrogen phosphite is disclosed for polymerizing 1,3-butadiene into syndiotactic 1,2-polybutadiene. The use of the catalyst composition of this disclosure avoids the use of environmentally detrimental components such as carbon disulfide and halogenated solvents. The melting temperature of the syndiotactic 1,2-polybutadiene can be varied from about 100 to about 190 ° C. by variations in the catalyst components and the component ratios. The ability to vary the melting temperature with a single catalyst composition is very desirable. The syndiotactic 1,2-polybutadiene can be used as a plastic or as an additive for rubber compositions wherein it can crosslink with conventional rubbers using conventional crosslinking agents.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients including an iron-containing compound, a hydrogen phosphite, and a mixture of two or more organoaluminum compounds. This catalyst composition is particularly useful for polymerizing conjugated dienes. When this catalyst composition is used to polymerize 1,3-butadiene into syndiotactic 1,2-polybutadiene the ratio of the organoaluminum compounds can be adjusted to vary the melting temperature and molecular weight of the polymer product.

Abstract: A catalyst composition comprising (a) an iron-containing compound, (b) an organomagnesium compound and (c) a dihydrocarbyl hydrogen phosphite is disclosed for polymerizing 1,3-butadiene into syndiotactic 1,2-polybutadiene. The use of the catalyst composition of this disclosure avoids the use of environmentally detrimental components such as carbon disulfide and halogenated solvents. The melting temperature of the syndiotactic 1,2-polybutadiene can be varied from about 100 to about 190° C. by variations in the catalyst components and the component ratios. The ability to vary the melting temperature with a single catalyst composition is very desirable. The syndiotactic 1,2-polybutadiene can be used as a plastic or as an additive for rubber compositions wherein it can crosslink with conventional rubbers using conventional crosslinking agents.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients including an iron-containing compound, a hydrogen phosphite, a halogen-containing compound, and an organoaluminum compound. This catalyst composition is particularly useful for preparing oligomers of conjugated dienes.

Abstract: Olefin polymerization is performed in the presence of a catalyst comprising a compound of the formula wherein M is a Group 3-10 transition metal; A is O, S, N—R″, or P—R″; L is an anionic ligand; X is hydride, halide, C1-C20 alkoxy, siloxy, hydrocarbyl, or dialkylamido; R, R′, and R″, which are the same or different, are selected from the group consisting of hydrogen and C1-C20 hydrocarbyl; and m+n equals the valency of M minus 1; and an activator.

Abstract: A catalyst composition comprising (a) an iron-containing compound, (b) a dihydrocarbyl hydrogen phosphite, and (c) an organoaluminum compound is disclosed for polymerizing 1,3-butadiene into syndiotactic 1,2-polybutadiene. The use of the catalyst composition of this disclosure avoids the use of environmentally detrimental components such as carbon disulfide and halogenated solvents. The melting temperature of the syndiotactic 1,2-polybutadiene can be varied from about 100 to about 200° C. by variations in the catalyst components and the component ratios. The ability to vary the melting temperature over such a broad range with a single catalyst composition is very desirable. The syndiotactic 1,2-polybutadiene can be used as a plastic or as an additive for rubber compositions wherein it can crosslink with conventional rubbers using conventional crosslinking agents.

Abstract: A process for preparing conjugated diene polymers by polymerizing conjugated diene monomers in the presence of a catalyst composition that is formed by combining an iron-containing compound, a hydrogen phosphite, and an organoaluminum compound.

Abstract: A method of preparing generally amorphous copolymers of ethylene and at least one norbornene (NB)-type comonomer. These polymers may be random or alternating, depending on the choice of catalyst and/or the relative ratio of the monomers used. This method comprises polymerizing said monomers in a diluent or in bulk in the presence of a cationic palladium catalyst resulting from reacting a chelating ligand with a palladium (II) compound. The catalysts employed in this invention may be represented by the formula: wherein X and Y each independently is a donor heteroatom selected from P, N, O, S and As or an organic group containing said heteroatoms, and the heteroatoms are bonded to the bridging group A; A is a divalent group selected from an organic group and phosphorus forming together with X, Y and Pd a 4, 5, 6, or 7-membered ring, and preferably a 5-membered ring; R is a hydrocarbyl group; and CA is a weakly coordinating anion.

Abstract: Aluminum-phosphinimine complexes function as a component in a catalyst system for the (co)polymerization of ethylene. The inventive catalyst components form a highly productive polymerization system when activated with so-called “ionic activators”. The need for conventional transition metal catalyst metals (such as titanium, hafnium, zirconium or vanadium) is eliminated.

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

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients including an iron-containing compound, a hydrogen phosphite, and an aluminoxane. This catalyst composition is useful for polymerizing conjugated diene monomers and is particularly useful for polymerizing 1,3-butadiene into syndiotactic 1,2-polybutadiene.

Abstract: The instant invention teaches a method for forming a syndiotactic 1,2-polybutadiene product having a syndiotacticity of more than 66.5% and a melting temperature of more than about 100° C. The method includes polymerizing 1,3-butadiene in solution with a solvent, in the presence of catalytically effective amounts of: (a) an organomagnesium compound; (b) a chromium compound; and, (c) a dihydrocarbyl hydrogen phosphite. The present invention also contemplates a product of the method and an article made from the product.

Abstract: A catalyst composition comprising (a) an iron-containing compound, (b) a cyclic hydrogen phosphite, and (c) an organoaluminum compound is disclosed for polymerizing 1,3-butadiene into syndiotactic 1,2-polybutadiene. The use of the catalyst composition of this disclosure avoids the use of environmentally detrimental components such as carbon disulfide and halogenated solvents. The melting temperature of the syndiotactic 1,2-polybutadiene can be varied from about 125 to about 175° C. by variations in the catalyst components and the component ratios. The ability to vary the melting temperature over such a broad range with a single catalyst composition is very desirable. The syndiotactic 1,2-polybutadiene can be used as a plastic or as an additive for rubber compositions wherein it can crosslink with conventional rubbers using conventional crosslinking agents.

Abstract: Novel aminomethylphosphine ligands have particular substituents on the central carbon atom. Such ligands form coordination complexes that may be catalysts for the polymerization of monomers or other catalytic induced reactions.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients including an iron-containing compound, an organomagnesium compound, and a cyclic hydrogen phosphite. This catalyst composition is particularly useful for polymerizing 1,3-butadiene into binary cis-1,4/1,2-polybutadiene.

Abstract: The invention encompasses late transition metal catalyst systems and their use in polymerization processes, particularly in solution, 2-phase suspension and super-critical phase polymerization of ethylene-containing polymers. Preferred embodiments include the use of a late transition metal catalyst system comprising a Group 8, 9, 10, or 11 metal complex stabilized by a bidentate ligand structure for polymerization under elevated ethylene pressure, or concentration, conditions.

Abstract: The present invention provides a novel catalyst system which can be preferably used in the trimerization, oligomerization reaction or polymerization reaction of an olefin, and a method for the trimerization, oligomerization or polymerization reaction of an olefin, which comprises using the catalyst system. A catalyst system obtained by contacting the following components (A) to (C):(A) a chromium compound,(B) an imine compound, and(C) a metal alkyl compound, and a method for the trimerization, oligomerization or polymerization reaction of an olefin, which comprises using the catalyst system are disclosed.

Abstract: This invention relates to an initiator system for the polymerization of isoolefins having 4 to 16 carbon atoms, optionally with monomers polymerizable with isoolefins, the system consisting of or one or more aromatic or heteroaromatic, polycyclic hydrocarbons and an aged, organic solution of vanadium tetrachloride, wherein the concentration of the vanadium tetrachloride is 0.01 mmol to 500 mmol per liter of solvent and the molar ratio of aged vanadium tetrachloride to polycyclic hydrocarbons is in the range from 100:1 to 1:100.It is possible by means of the initiator system according to the invention to produce polyisoolefins, in particular butyl rubbers, at relatively high temperatures with only a low gel content and of a sufficiently high molecular weight.

Abstract: A process for polymerizing 1,3-butadiene into syndiotactic 1,2-polybutadiene is described using a catalyst system comprising (a) a chromium-containing compound, (b) an organoaluminum hydride, and (c) a hydrogen phosphite. The use of the catalyst system avoids the use of environmentally detrimental components such as carbon disulfide and halogenated solvents. The syndiotactic 1,2-polybutadiene can be used as a plastic or as an additive for rubber compositions wherein it can crosslink with conventional rubbers using conventional crosslinking agents.

Abstract: Diene rubbers are produced in the gas phase by first polymerizing the dienes or diene mixtures in the presence of a catalyst system, which is based on rare earth compounds, at temperatures of from 0 to 150.degree. C. and at pressures of from 1 mbar to 50 bar, so that a pourable diene rubber having a Mooney viscosity ML (1+4', 100.degree. C.) of 70 to 180 Mooney units is obtained, and subsequently subjecting the pourable diene rubber obtained to a chemical or thermal decomposition reaction until a Mooney viscosity of 10 to 70 Mooney units is obtained.

Abstract: A process for the preparation of a 1,2-vinyl-polybutadiene with an adjustable amount of vinyl linkages in the microstructure of the polymer which comprises polymerizing 1,3-butadiene in a gas phase reactor under polymerization conditions using an inert gas in the presence of a catalyst comprising: (a) a cobalt compound; (b) a compound selected from the group consisting of a phosphine, a xanthogen, a thiocyanide, a carbon disulfide, and mixtures thereof; and (c) an organoaluminum compound, and optionally a modifier (d) can be included in the catalyst composition. There is also provided a novel resin particle prepared by the process.

Abstract: Olefins or mixtures of olefins, particularly propene or mixtures of propene advantageously with ethene, can be polymerized using a Ziegler-Natta catalyst system containing, besides a transition-metal-based procatalyst and cocatalyst which is an organometallic compound, a compound particularly suited for controlling the stereospecificity of the produced polymer. Such a compound called an external donor may also have other effects. By using an acetal derivative of an aldehyde that has two ether groups for this purpose, advantageously selected from the group of dialkoxyphenylalkanes, e.g., dimethoxyphenylpropane, a good stereospecificity of the product is attained combined with the high hydrogen sensitivity of the catalyst system, whereby the use of hydrogen as the chain transfer agent offers an easy control method of the molecular weight of the product by means of adjusting the amount of hydrogen available in the polymerization reaction.

Abstract: Certain olefins such as ethylene, .alpha.-olefins and cyclopentene can be polymerized by using catalyst system containing a nickel or palladium .alpha.-diimine complex, a metal containing hydrocarbylation compound, and a selected Lewis acid, or a catalyst system containing certain nickel ?II! or palladium ?II! compounds, an .alpha.-diimine, a metal containing hydrocarbylation compound, and optionally a selected Lewis acid. The process advantageously produces polyolefins useful for molding resins, films, elastomers and other uses.

Abstract: Process for the polymerization of alpha-olefins, which is carried out in the presence of a catalyst system comprising:(1) a solid based on completed titanium trichloride;(2) an organometallic compound of metals of groups IA, IIA, IIB and IIIB of the Periodic Table, and(3) an electron-donor organic compound, the solid (1) based on complexed titanium trichloride having been preactivated by being brought into contact with a preactivator comprising the product of reaction of a trialkylaluminum or alkylaluminum chloride compound (a) and of a compound (b) chosen from hydroxyaromatic compounds whose hydroxyl group is sterically hindered, then isolating the predetermined solid (1) from the medium in which it was found.This process enables propylene to be polymerized with an improved stereospecificity without any significant decrease in catalyst activity.

Abstract: Syndiotactic 1,2-polybutadiene is a thermoplastic resin which has double bonds attached in an alternating fashion to its polymeric backbone. Films, fibers and molded articles can be made utilizing syndiotactic 1,2-polybutadiene. It can also be blended into rubbers and cocured therewith. It is generally preferred to synthesize syndiotactic 1,2-polybutadiene in an aqueous medium by suspension or emulsion polymerization. In such aqueous polymerization techniques reactor fouling and particle size control problems are frequently encountered. This invention is based upon the unexpected finding that reactor fouling can be greatly reduced or eliminated and that particle size can be regulated by conducting such aqueous polymerizations in the presence of a controlled amount of dissolved oxygen which is within the range of about 0.01 ppm to about 4 ppm.

Abstract: The dispersion polymerization of isobutylene includes a dispersing agent. The dispersing agent is a compound having a CO.sub.2 -phobic moiety and at least one CO.sub.2 -philic moiety. The CO.sub.2 -phobic moiety is polysibutylene-philic. Novel polymerization initiators are organometallic.

Abstract: A catalyst composition comprising a bis-amide compound represented by the formula ##STR1## wherein M is zirconium, hafnium or titanium; each N is a three coordinate nitrogen atom; each e is Si, Ge or Sn; each Z is, independently, a hydride or R; each R is, independently, a hydrocarbyl one or more carbon atoms of which may be substituted by an element selected from Si, O, P, N and S; L is a neutral Lewis base and m is a number from 0 to 2; or a dimer thereof and a second component. Preferably the second component is a compound which is capable of providing a bulky and labile anion ?A!.sup.-, which anion is substantially non-coordinating under the reaction conditions and contains at least one boron atom. Also provided is a process for oligomerizing or co-oligomerizing alpha olefins in the presence of this catalyst composition.

Abstract: A process for producing a polybutadiene rubber having a cis-1,4 content of 94% or more, a ratio of weight average molecular weight to number average molecular weight of 2.5 to 3.5 as measured by a gel permeation chromatography and a Mooney viscosity (ML.sub.1+4, 100.degree. C.) of 20 to 100, which process comprises polymerizing 1,3-butadiene in an inert organic solvent with a catalyst comprising as the main components (a) a nickel compound; (b) a specific fluorine compound; (c) a trialkylaluminum; and (d) a halogenated aldehyde and/or a quinone compound. The use of the specific catalyst enables the production in a high yield of a polybutadiene rubber which maintains the abrasion resistance, high impact resilience and low heat buildup which are the characteristics of polybutadiene rubber and has a small die swell when extruded in the form of a blend with a natural rubber and is excellent in physical properties of vulcanizate.

Abstract: In a process for producing syndiotactic-1,2-polybutadiene by suspension polymerization wherein a mixture composed of 1,3-butadiene, a cobalt compound, and an organometallic compound or metal hydride containing a metal of group I, II or III of the periodic table is contacted with an initiator selected from the group consisting of carbon disulfide, phenyl isothiocyanate and xanthogenic compounds in an aqueous medium, the improvement comprising, after the preparation of the mixture, adding thereto an anti gelling agent selected from the group consisting of alcohols, aldehydes, ketones, carboxylic acid esters, nitriles, sulfoxides, amides and phosphoric acid esters, whereby the formation of a rubber-like gelation product in the mixture is inhibited.

Abstract: This invention relates to a process for preparation of non-crosslinked linear monofunctional and telechelic difunctional unsaturated polymers wherein the functional groups are acrylate or methacrylate groups. The average functionality number of the monofunctional unsaturated polymers is at least 0.7, as determined by nuclear magnetic resonance spectroscopy (NMR). The average functionality number of the telechelic difunctional polymers is at least 1.7, as determined by NMR. Alkyl acrylates or alkyl methacrylates are reacted with cyclic olefinic non-conjugated compounds or unsaturated hydrocarbon polymers to prepare monofunctional and difunctional polymers. The process is substantially free of side reactions comprising double bond migration and cyclization.

Abstract: Diene polymers having a high content of trans-1,4 addition and two distinct melting points in the ranges of 30.degree. C. to 50.degree. C. and 70.degree. C. to 130.degree. C. are prepared by polymerizing a 1,3-diene monomer in a hydrocarbon solvent in the presence of a catalyst composition comprising (a) a carboxylated nickel oxy borate compound; (b) an orKanoaluminum compound; (c) a triaryloxy phosphorus compound and (d) a carboxylic acid preferably a fluorinated carboxylic acid. The resultant polymers are useful as additives to tire rubbers to improve processability by reducing compound Mooney viscosity and reducing the shrinkage of various compound stocks.

Abstract: This invention relates to difunctional telechelic linear non-crosslinked polyolefins without pendant chain branched groups. The polyolefin compounds of this invention are useful for preparing high molecular weight polyesters, polyamides, polyureas and polyurethanes of high density without branching of the polymer chains, and with low permeability to gases and solvents.

Abstract: A novel Phillips catalyst for the copolymerization of ethylene with .alpha.-olefins, contains, as a catalytically active component, a finely divided, aluminum silicate-supported, phosphorus-containing chromium catalyst. This can be prepared by applying at least one organic phosphorus(III), (IV) and/or (V) compound and at least one chromium(III) compound which does not react with said phosphorus compounds under the reaction conditions used, in succcession in any order or simultaneously, to a finely divided aluminum silicate hydrogel or xerogel with formation of a catalyst intermediate and activating the catalyst intermediate at elevated temperatures in an oxidizing atmosphere, with the result that the chromium catalyst is formed. The novel Phillips catalyst gives ethylene/.alpha.-olefin copolymers in which the comonomers are more uniformly distributed over the copolymer chains than is the case with ethylene/.alpha.-olefin copolymers which have been prepared with the aid of conventional Phillips catalysts.