Abstract: A process for preparing a multimodal polyethylene product with at least two different polyethylene resins includes producing a first polyethylene resin in the presence of a Ziegler-Natta catalyst in a reactor. The Ziegler-Natta catalyst used for the production of the first polyethylene resin has an average particle size (D50) of at most 15 ?m. The process includes separately producing a second polyethylene resin in the presence of a Ziegler-Natta catalyst in a reactor. The process includes physically blending together the first and second polyethylene resins to produce a multimodal polyethylene product.

Abstract: A solid titanium catalyst component (I) comprising titanium, magnesium, halogen, a specific cyclic ester compound (a) and a specific cyclic ester compound (b), an olefin polymerization catalyst containing this catalyst component (I), and an olefin polymerization process using this olefin polymerization catalyst are disclosed. According to the solid titanium catalyst component, the olefin polymerization catalyst and the process for preparing an olefin polymer of the invention, an olefin polymer having high stereoregularity and a wide molecular weight distribution can be prepared with high activity, preparation of an olefin polymer excellent not only in molding properties such as high-speed streatchability and high-speed moldability but also in rigidity becomes possible, and besides, production cost can be reduced.

Abstract: The invention relates to A process for the polymerization of ethylene to produce a polyethylene resin in at least two slurry loop reactors connected to each other in series, the resin having a bimodal molecular weight distribution, a molecular weight distribution MWD of at least 7.0, an HLMI of from 1 to 100 g/10 min, and a density of from 0.935 to 0.960 g/cm3, wherein in one reactor 30 to 47 wt % based on the total weight of the polyethylene resin of a high molecular weight (HMW) polyethylene fraction is produced having an HL275 of from 0.05 to 1.8 g/10 min (the equivalent of HLMI of from 0.01 to 1.56 g/10 min), a density of from 0.925 to 0.942 g/cm3 and an MWD of at least 5.0, and in the other reactor a low molecular weight (LMW) polyethylene fraction is produced having an HLMI of from 10 to 1500 g/10 min and a density of from 0.960 to 0.975 g/cm3, in the presence of a Ziegler-Natta catalyst system.

Abstract: Low-viscosity drag reducers, systems for delivering low-viscosity drag reducers, and methods of making low-viscosity drag reducers are disclosed. The low-viscosity drag reducers have a viscosity less than 350 cP at a shear rate of 250 sec?1 and a temperature of 60° P. This low-viscosity allows the drag reducers to be delivered through a long and relatively small diameter conduit of a subsea umbilical line without an unacceptable level of pressure drop or plugging of the conduit. The low-viscosity drag reducers can be delivered to a subsea flowline carrying fluids produced from a subterranean formation to 10 thereby provide significant drag reduction in the flow line.

Abstract: The present invention relates to catalyst systems containing solid catalyst components comprising titanium, magnesium, halogen and an internal electron donor compound having at least one ether group and at least one ketone group; organoaluminum compounds and alkyl benzoate derivatives as external electron donors. The present invention also relates to methods of making the catalyst systems, and methods of polymerizing or copolymerizing alpha-olefins using the catalyst systems.

Abstract: There is provided a process for producing a prepolymerization catalyst for polymerization of an olefin, said process comprising the steps of feeding, to a polymerization reactor, an olefin and a solid catalyst component in which a catalyst component for polymerization of the olefin is carried on a fine particle support, and prepolymerizing the olefin in the presence of the solid catalyst component in the polymerization reactor, to thereby obtain the prepolymerization catalyst in which the olefin is prepolymerized on the solid catalyst component, characterized in that said solid catalyst component is pressure-fed to the polymerization reactor from a catalyst feeder connected to the polymerization reactor, and in that the inner pressure of the catalyst feeder at the start of the pressure-feeding is set at (Pr+0.0001) to (Pr+1) (MPa in unit) (in which Pr represents the inner pressure of the polymerization reactor (MPa in unit) at the start of the pressure-feeding).

Abstract: A catalyst composition for the polymerization of propylene comprising one or more Ziegler-Natta procatalyst compositions comprising one or more transition metal compounds and one or more esters of aromatic dicarboxylic acid internal electron donors; one or more aluminum containing cocatalysts; a selectivity control agent (SCA) comprising at least one silicon containing compound containing at least one C1-10 alkoxy group bonded to a silicon atom, and one or more activity limiting agent (ALA) compounds comprising one or more aliphatic or cycloaliphatic carboxylic acids; alkyl-, cycloalkyl- or alkyl(poly)(oxyalkyl)-(poly)ester derivatives thereof; or inertly substituted derivatives of the foregoing.

Abstract: Copolymers, especially multi-block copolymer containing therein two or more segments or blocks differing in chemical or physical properties, are prepared by polymerizing propylene, 4-methyl-1-pentene, or other C4-8?-olefin and one or more copolymerizable comonomers, especially ethylene in the presence of a composition comprising the admixture or reaction product resulting from combining: (A) a first metal complex olefin polymerization catalyst, (B) a second metal complex olefin polymerization catalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by catalyst (A) under equivalent polymerization conditions, and (C) a chain shuttling agent.

Abstract: A catalyst composition for the polymerization of propylene comprising one or more Ziegler-Natta procatalyst compositions comprising one or more transition metal compounds and one or more esters of aromatic dicarboxylic acid internal electron donors; one or more aluminum containing cocatalysts; a selectivity control agent (SCA) comprising at least one silicon containing compound containing at least one C1-10 alkoxy group bonded to a silicon atom, and one or more activity limiting agent (ALA) compounds comprising one or more aliphatic or cycloaliphatic carboxylic acids; alkyl-, cycloalkyl- or alkyl(poly)(oxyalkyl)-(poly)ester derivatives thereof; or inertly substituted derivatives of the foregoing.

Abstract: A process for producing an olefin copolymerization catalyst, comprising the step of contacting, with one another, (A) a solid catalyst component containing a titanium atom, a magnesium atom and a halogen atom, (B) an organoaluminum compound and/or organoaluminumoxy compound, and (C) a nitrogen-containing aromatic heterocyclic compound, whose one or more carbon atoms adjacent to its nitrogen atom are linked to an electron-withdrawing group, or a group containing an electron-withdrawing group; and a process for producing an olefin copolymer using the an olefin copolymerization catalyst.

Abstract: The present invention relates to a catalyst for synthesizing a polypropylene with a wide molecular weight distribution and use of the same. The catalyst comprises magnesium halide, titanium-containing compound, and an organic phosphate type electron donor compound. By the catalyst according to the present invention, a propylene polymer with a wide molecular weight distribution, easily controllable isotacticity and good processing properties can be synthesized.

Abstract: The present invention relates to a method for preparing a solid catalyst for ethylene polymerization and/or copolymerization. More specifically, the present invention relates to a solid titanium catalyst supported in a magnesium support which has an extremely high catalytic activity, advantageous catalyst shape and a simple preparation process, capable of producing a polymer with a high bulk density, a narrow and uniform particle size distribution and a broad molecular weight distribution, and a method for preparation of the same. A silicon-containing magnesium compound is prepared by reacting an electron donor such as a silicon compound containing an alkoxy group of Formula 1, a silicon compound containing an alkoxy group of Formula 2, or a mixture thereof in a magnesium compound solution, and reacted with a titanium compound to obtain the solid catalyst of the present invention.

Abstract: A catalyst for olefin polymerization comprising (A) a solid catalyst component prepared by causing (a) a magnesium compound, (b) a tetravalent titanium halide compound, and (c) an electron donor compound to come in contact with each other, (B) an organoaluminum compound of the general formula R1pAlQ3-p, and (C) an oligomer of an organosilicon compound of the following chemical formula; R4—(R2R3SiO)m—R5 can produce olefin polymers having higher stereoregularity and a broader molecular weight distribution in a higher yield than conventional catalysts.

Abstract: The invention relates to methods for producing cesium hydroxide solutions during which: cesium-containing ore is disintegrated with sulfuric acid while forming a cesium aluminum sulfate hydrate, which is poorly soluble at low temperatures; the formed cesium alum is separated away in the form of a solution from the solid ore residues; the aluminum is precipitated out of the cesium alum solution while forming a cesium sulfate solution; the formed cesium sulfate solution is reacted with barium hydroxide or stontium hydroxide while forming a cesium hydroxide solution, and; the formed cesium hydroxide solution is concentrated and purified.

Abstract: The invention refers to a process for preparing a Group 2 metal/transition metal olefin polymerization catalyst component in particulate form having an improved high temperature activity and the use thereof in a process for polymerizing olefins.

Abstract: The invention relates to a process for preparing a poly-1-olefin by polymerization of a 1-olefin of the formula R4CH?CH2, where R4 is hydrogen or an alkyl radical having from 1 to 10 carbon atoms, in suspension, in solution or in the gas phase, at a temperature of from 20 to 200° C. and a pressure of from 0.

Abstract: Low-viscosity drag reducers, systems for delivering low-viscosity drag reducers, and methods of making low-viscosity drag reducers are disclosed. The low-viscosity drag reducers have a viscosity less than 350 cP at a shear rate of 250 sec?1 and a temperature of 60° F. This low-viscosity allows the drag reducers to be delivered through a long and relatively small diameter conduit of a subsea umbilical line without an unacceptable level of pressure drop or plugging of the conduit. The low-viscosity drag reducers can be delivered to a subsea flowline carrying fluids produced from a subterranean formation to thereby provide significant drag reduction in the flowline.

Abstract: A method for producing an ethylene polymer which comprises continuously polymerizing ethylene alone or copolymerizing ethylene and a C3-C8 ?-olefin by multistage polymerization in a plurality of polymerization reactors connected in series in the presence of a chromium catalyst having at least a part of chromium atoms converted to hexavalent chromium carried on an inorganic oxide carrier by calcination-activating in a non-reducing atmosphere, wherein an organoaluminum compound of the formula (1): (R1)xAl(OR2)y(OSiR3R4R5)z??(1) (in the above formula, R1 and R2 may be the same or different, each represents a C1-C18 alkyl group or a C6-C18 aryl group, R3, R4 and R5 may be the same or different, each represents a C1-C18 alkyl group or a C6-C18 aryl group, R1, OR2 and OSiR3R4R5 respectively may be the same or different when each has a plurality of kinds, and x, y and z are respectively 0?x?3, 0?y<3, 0?z<3, and x+y+z=3) is introduced at least one or all of the polymerization reactors.

Abstract: The present invention discloses a polyethylene catalyst and a process for preparing the same, said catalyst being composed of a main component of catalyst and a cocatalyst, wherein the main component of catalyst is prepared by reacting: (1) a magnesium-alcohol complex, (2) an alkyl aluminum compound having a formula R3nAlCl3-n supported on silica, and (3) a titanium compound having a formula Ti(OR2)mCl4-m, and the cocatalyst is an organic aluminum compound. The catalyst of the present invention has advantages including high polymerization activity, less difference between the polymerization activities at low hydrogen level condition and at high hydrogen level condition, stable polymerization reaction, good particle morphology of catalyst, and less fine powder of polymer product.

Abstract: A highly active alpha-olefin polymerization catalyst component is disclosed. In the presence of a co-catalyst, the catalyst component is useful for the production of LLDPE resins. The catalyst component is produced by a method whereby organic silicon compounds are reacted with a transition metal complex and active transition metal species is deposited on a silicon-containing MgCl2 that is prepared in situ in the presence of the organic silicon compounds.

Abstract: Disclosed is a method of polymerization and copolymerization of ethylene, which is carried out in the presence of (a) a solid titanium complex catalyst prepared by the steps of (i) preparing a magnesium solution by contacting halogenated magnesium compounds with alcohol, (ii) reacting the magnesium solution with ester compound having at least one hydroxyl group and silicon compound having alkoxy group, (iii) preparing a solid titanium catalyst component by reacting mixture of titanium compound and haloalkane compound; and (iv) producing solid titanium complex catalyst by reacting the solid titanium catalyst component with mixture of aluminum compound and haloalkane compound, or with haloalkane; and (b) organometallic compounds in Group II or III of the Periodic Table.

Abstract: The present invention provides a method for producing homo- and co-polymers of ethylene, or more particularly a method for producing homo- and copolymers of ethylene in the presence of (a) a solid titanium catalyst produced by preparing a magnesium solution by contact-reacting a halogenated magnesium compound with an alcohol; reacting thereto an ester compound having at least one hydroxyl group and a silicon compound having at least one alkoxy group; and adding a mixture of a titanium compound and a silicon compound; (b) organometallic compounds of Group II or III of the Periodic Table; and (c) an alkoxysilane compound and a haloalkne compound. The catalyst for homo- and co-polymerization of ethylene, produced according to the present invention, exhibits a high activity and the polymers produced by the method of the present invention using said catalyst have the advantages of exhibiting a high bulk density and a narrow molecular weight distribution.

Abstract: There are provided a process for producing a catalyst for ?-olefin polymerization, which comprises the step of contacting (1) a solid catalyst component having Ti, Mg and a halogen as essential components, (2) an organoaluminum compound and (3) a compound having a —C—O—C—O—C— bond group in a closed ring structure with one another; and a process for producing an ?-olefin polymer, which comprises the step of homopolymerizing or copolymerizing an ?-olefin in the presence of a catalyst for ?-olefin polymerization produced by the above process.

Abstract: Provided are catalysts for styrene polymerization capable of efficiently and inexpensively producing styrenic polymers having a syndiotactic structure; and a method for producing styrenic polymers. The catalysts comprise (A) a transition metal compound, (B) an oxygen-containing compound and/or a compound capable of reacting with a transition metal compound to form an ionic complex, (C) a specific metal compound, preferably a specific organoaluminium compound of a general formula: ((R1)3—CO)n-Al—(R2)3−n wherein R1 represents an aliphatic hydrocarbon group having from 1 to 30 carbon atoms, an aromatic hydrocarbon group having from 6 to 30 carbon atoms or the like; R2 represents a hydrocarbon group; n is 1 or 2, and optionally (D) an alkylating agent. In the method for producing styrenic polymers, used is the catalyst.

Abstract: The invention relates to an anionically polymerised, impact-resistant polystyrene with a dispersed plasticiser phase, comprising particles with capsule particle morphology and method for production thereof.

Abstract: Disclosed is a solid titanium catalyst component which is obtained by a process comprising the steps of bringing (a) a liquid magnesium compound into contact with (b) a liquid titanium compound in the presence of (c) an organosilicon compound having no active hydrogen in an amount of 0.25 to 0.35 mol based on 1 mol of the magnesium compound (a), elevating the temperature of the resulting contact product to a temperature of 105 to 115° C. and maintaining the contact product at this temperature. The contact product may be further brought into contact with not more than 0.5 mol of the organosilicon compound having no active hydrogen (c). Also disclosed are an ethylene polymerization catalyst formed from the solid titanium catalyst component and an organometallic compound and an ethylene polymerization process using the catalyst. By the use of the solid titanium catalyst component, ethylene can be polymerized with high activities and an ethylene polymer having excellent particle properties can be prepared.

Abstract: A modified aluminoxane is disclosed. Aluminoxane compounds are modified with glycol ethers or polyethers. The modified aluminoxanes are effective activators for single-site catalysts. Catalyst activated with the modified aluminoxane produces polyolefin with increased melt flow index, broadened molecular weight distribution, and improved thermal processability.

Abstract: A process is provided for preparing a catalyst support for polymerizing &agr;-olefins comprising the steps of: (i) reacting, in the presence of a first electron donor, a chlorine-containing organic compound and a prior mixture of an alkylmagnesien and an aluminoxane and/or aluminosiloxane and/or alkylaluminum and, optionally, a second electron donor; and (ii) activating a product from step (i) in suspension in an inert liquid by means of an activation electron donor, together with the support thus obtained, a catalyst for polymerizing &agr;-olefins, comprising this catalyst support and a group IV transition metal halide, and a process for polymerizing &agr;-olefins, particularly propylene, comprising contacting the &agr;-olefin with the catalyst.

Abstract: The present invention relates to a method for producing a polymer and copolymer of ethylene, and more particularly to a method for producing an ethylene polymer and copolymer by reacting a compound of an organic metal of Group 2, 12, or 13 on the periodic table of elements with an alkoxy silane compound in the presence of a titanium catalyst, the said titanium catalyst being produced by a process of preparing a magnesium compound by contact-reacting a halogenated magnesium compound and alcohol, of reacting the said solution with an ester compound which contains at least one hydroxy group and a silicon compound containing an alkoxy group, and also of reacting it with a solid matter obtained by reaction of a mixture of a titanium compound and a silicon compound with a titanium compound.

Abstract: Disclosed are catalysts for the polymerization of alpha-olefins which comprise the reaction product of: (a) an Al-alkyl compound; (b) a silicon compound containing at least one Si—OR or Si—OCOR or Si—NR2 bond, R being a hydrocarbyl radical; (c) a solid comprising, as essential support, a Mg dihalide in active form and, supported thereon, a Ti halide or a halo-Ti-alcoholate and a particular type of electron donor compound. The present invention refers to new supported components of catalysts for the polymerization of CH2═CHR olefins wherein R is an alkyl radical with 1 to 4 carbon atoms, or an aryl radical, and mixtures of said olefins with ethylene and the catalysts obtained from said components.

Abstract: A process for the production of an ionic transition metal catalyst in supported form than is highly productive under gas phase olefin polymerization conditions. In the process a an aluminum alkyl is added to a suitable solvent after which a neutral metallocene compound is added to the solution under stirring in a quantity that provides for a ratio of Al to transition metal of at least 25:1. To this metallocene-aluminum alkyl solution is next added an ionic compound the anionic portion of which is a non-coordinating anion under stirring until all materials are dissolve. The ionic compound is added in a quantity that provides for a ratio of NCA to transition metal of at least 1:1. Next the support particles are added to the solution and thereafter the solution is heated to at least 40° C. and held at this elevated temperature for at least 0.5 hour. Thereafter the solvent is removed and the supported catalyst is dried under vacuum.

Abstract: A process as disclosed for producing a low density polyethylene using a particle form polymerization process and a titanium-containing catalyst wherein the ratio of comonomer to ethylene is at least about 1:1 and the titanium-containing catalyst is a special catalyst which has been pretreated with an organometallic reducing agent.

Abstract: A modified aluminoxane is disclosed. Aluminoxane compounds are modified with glycol ethers or polyethers. The modified aluminoxanes are effective activators for single-site catalysts. Catalyst activated with the modified aluminoxane produces polyolefin with increased melt flow index, broadened molecular weight distribution, and improved thermal processability.

Abstract: There are provided (1) a process for producing a solid product, which comprises the step of reducing a titanium compound represented by the following formula [I] with an organomagnesium compound in the presence of an organosilicon compound having an Si—O bond, an inorganic fine particle and optionally an ester compound, (2) a process for producing a solid catalyst component, which comprises the step of contacting the solid product obtained by the above process, a halogenation ability-carrying halogeno compound, and an inner electron donor compound, (3) a process for producing a catalyst, which comprises the step of contacting the solid catalyst component obtained by the above process, an organoaluminum compound, and an outer electron donor compound, and (4) a process for producing an olefin polymer, which comprises the step of polymerizing an olefin in the presence of the catalyst obtained by the above process.

Abstract: There are provided a process for producing a catalyst for &agr;-olefin polymerization, which comprises the step of contacting (1) a solid catalyst component having Ti, Mg and a halogen as essential components, (2) an organoaluminum compound and (3) a compound having a —C—O—C—O—C— bond group in a closed ring structure with one another; and a process for producing an &agr;-olefin polymer, which comprises the step of homopolymerizing or copolymerizing an &agr;-olefin in the presence of a catalyst for &agr;-olefin polymerization produced by the above process.

Abstract: Processes for the formulation of Ziegler-type catalysts from a plurality of catalyst components including transition metal, organosilicon electron donor, and organoaluminum co-catalyst components. The components are mixed together in the course of formulating the Ziegler-type catalyst to be charged to an olefin polymerization reactor. Several orders of addition of the catalyst components can be used in formulating the Ziegler catalyst. One involves mixing of the transition metal component with the organoaluminum co-catalyst to formulate a mixture having an aluminum/transition metal mole ratio of at least 200. This mixture is combined with the organosilicon electron donor component to produce a Ziegler-type catalyst formulation having an aluminum/silicon mole ratio of no more than 50. There may be an initial pre-polymerization of the catalyst prior to introducing the catalyst into an olefin polymerization reactor.

Abstract: Modified polybutadiene having a high-cis and low-trans structure with a moderate 1,2-structure content and exhibiting improved characteristics such as cold flow properties, which is obtained by modifying starting polybutadiene having a Tcp/ML1+4 ratio (Tcp: 5% toluene solution viscosity at 25° C.ML1+4: Mooney viscosity at 100° C.) of 2.5 or more in the presence of a transition metal catalyst.

Abstract: A polymerisation process for the preparation of vinylic polymers from the corresponding vinylic monomers which process comprises the step of reacting a vinylic monomer in the presence of a catalyst system comprising a) a metal complex of general formula (I) where A is selected from the group consisting of nickel, iron, cobalt, chromium, manganese, titanium, zirconium, vanadium and the rare earth metals; L1, L2, L3 and L4 are ligands and b) a Lewis acid of general formula (II) wherein at least one of W, Y or Z is capable of forming a co-ordination bond with A and the others of W, Y and Z are bulky groups; D is selected from the group consisting of aluminium, magnesium, zinc and boron.

Abstract: A prepolymerization catalyst for use in a gas phase polymerization of an olefin or combinations of olefins which comprises (A) a solid catalyst component comprising magnesium, halogen, titanium and an electron donor and having a weight-average particle diameter of 15 to 45 &mgr;m, (B) at least one organoaluminum compound and (C) a prepolymer of an ethylene and/or at least one &agr;-olefin, wherein the molar ratio of aluminum to titanium in the prepolymerization catalyst (Al/Ti ratio) is 3 to 11 (mol/mol), the weight ratio of the prepolymerization catalyst to the solid catalyst component (prepolymerization catalyst/solid catalyst component) is 2 to 35 (g/g), the content of volatile materials (VM) in the prepolymerization catalyst is 2.0% by weight or less, and the intrinsic viscosity [&eegr;] measured in tetralin at 135° C. is 2.0 dl/g or less, and a process for a production thereof.

Abstract: The present invention provides polypropylene having xylene solubles from 0.6 to 1.5 weight percent and isotacticity equal to or greater than about 98.0 percent. The polypropylene is obtained by contacting propylene monomer under suitable polymerization conditions with (a) a Ziegler-Natta catalyst, (b) a co-catalyst, and (c) an electron donor.

Abstract: A process for polymerizing propylene is disclosed. The process involves charging propylene and about 90 to 99% of an organoaluminum cocatalyst to a reactor and heating this mixture to at least about 50° C. This is followed by addition of a premix of 1 to 10% of the organoaluminum cocatalyst with a magnesium halide-supported Ziegler-Natta catalyst. The temperature of the reaction mixture is maintained to produce a propylene polymer. The process gives improved catalyst activity.

Abstract: The present invention relates to a method of homo- or co-polymerization of &agr;-olefin by means of using a catalyst system which comprises the following components: (1) a solid complex titanium catalyst produced by means of a production method comprising the following steps: (a) preparing a magnesium compound solution by dissolving a magnesium halide compound and a compound of Group IIIA of the Periodical Table in a solvent of mixture of cyclic ester, one or more types of alcohol, a phosphorus compound, and an organic silane; (b) precipitating the solid particles by reacting said magnesium compound solution with a transitional metal compound, a silicon compound, a tin compound, or the mixture thereof; and (c) reacting said precipitated solid particles with a titanium compound and electron donors; (2) an organometallic compound of metal of Group IIIA of the Periodical Table; and (3) external electron donors comprising three or more types of organo-silicon compounds, wherein the melt flow rates of the homopoly

Abstract: An olefin polymerization catalyst is described which includes: (A) a solid catalyst component being prepared by copulverizing a magnesium compound, an aluminum compound, an electron donor and a titanium compound, and (B) an organoaluminum compound. The present invention is also directed to a process for preparing polyolefins using the aforesaid catalyst system to polymerize olefins.

Abstract: The present invention relates to a highly active titanium based supported catalyst suitable for olefin (co)polymerization, preparation and use of the same. The catalyst according to the present invention is obtained by supporting a titanium based catalyst component containing a halide promoter on spherical silica. The resultant catalyst is excellent in its particle morphology and flowability, has highly catalytic activity, has excellent hydrogen response and has superior comonomer incorporation, the polymer prepared by using such a catalyst has its particle morphology further improved.

Abstract: There are disclosed: (1) a process for producing a catalyst for ethylene polymerization, which comprises the step of contacting with one another: (i) a solid catalyst component containing at least titanium, magnesium and halogen atoms; (ii) an organoaluminum compound; and (iii) a heterocyclic compound; and (2) a process for producing an ethylene polymer, which comprises the step of polymerizing ethylene, or ethylene and at least one kind of an addition polymerizable comonomer other than ethylene, in the presence of the above-mentioned catalyst.

Abstract: A polymerization process for the preparation of vinylic polymers from the corresponding vinylic monomers which process comprises the step of reacting a vinylic monomer in the presence of a catalyst system comprising a) a compound of general formula (I) where M is any metal capable of coordinating to an enolate or delocalized enolate-like species; B1, B2, B3 and B4 are chosen from nitrogen, oxygen, sulphur or phosphorus containing moieties wherein each of said nitrogen, oxygen, sulphur or phosporus is linked to at least one carbon atom of an organic group and to M; X1 is selected from the group consisting of alkyl, H, halogen, alkoxy, thiol aryloxy, ester, b) a metal, complex of general formula (II) where A is selected from the group consisting of nickel, iron, cobalt, chromium, manganese, titanium, zirconium, vanadium and the rare earth metals; L1, L2, L3 and L4 are ligands and c) a Lewis acid of general formula (III) wherein at least one of W, Y or Z is capable of forming a co-ordination bond with A and the

Abstract: Modified polybutadiene having a high-cis and low-trans structure with a moderate 1,2-structure content and exhibiting improved characteristics such as cold flow properties, which is obtained by modifying starting polybutadiene having a Tcp/ML1+4 ratio (Tcp: 5% toluene solution viscosity at 25° C.ML1+4: Mooney viscosity at 100° C.) of 2.5 or more in the presence of a transition metal catalyst.

Abstract: There are disclosed: (1) a process for producing a catalyst for olefin polymerization, which comprises the step of contacting with one another: (i) a solid catalyst component containing at least titanium, magnesium and halogen atoms, (ii) an organoaluminum compound, and (iii) a compound selected from the group consisting of (a) an oxygen-containing compound having a structure wherein at least two hydrocarbyloxy groups are bound to the same carbon atom, and (b) a cyclic ketone compound, and (2) a process for producing an olefin polymer, which comprises the step of polymerizing an olefin in the presence of the above-mentioned catalyst.

Abstract: The invention provides a process for producing polypropylene and/or random copolymers of propylene type using a stereoregular catalyst which comprises a titanium-containing solid catalyst component (A), an organoaluminum compound (B) and if required an organosilicon compound (C), wherein [I] before carrying out homopolymerization of propylene or random copolymerization of propylene with an &agr;-olefin other than propylene, the above component (A), an organoaluminum compound (B′) and if required an organosilicon compound (C′) are used, and a small amount of propylene or ethylene and/or an &agr;-olefin of 4-20 carbon atoms for pre-activation treatment is supplied to the above component (A), and [II] a catalyst which is prepared by adding an organosilicon compound (C″) to the pre-activated stereoregular catalyst in a molar ratio of 0.1-50 as Si/Ti, is used to produce polypropylene or propylene random copolymers.

Abstract: Superabsorbent polymers having a slow rate of absorption, and a process for their preparation. The superabsorbent polymer has a slow rate of absorption, is crosslinked with a covalent crosslinking agent and the metal of a polyvalent metal coordination compound, has the metal of the coordination compound distributed essentially homogeneously throughout the polymer, and has an Absorption Rate Index of at least about 5 minutes. Prepare water-swellable, water-insoluble polymer particles having a slow rate of water absorption by polymerizing a monomer in the presence of a covalent crosslinking agent and a polyvalent metal coordination compound under conditions such that there is formed a polymer having reversible cationic crosslinks and such that the metal is distributed essentially homogeneously throughout the polymer particles.