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; and a mixture of two or more different selectivity control agents, said SCA mixture comprising from 1 to 99 percent of one or more esters of one or more aromatic monocarboxylic acids or substituted derivatives thereof, and from 99 to 1 percent of one or more alkoxysilane compounds.

Abstract: Provided herein are propylene polymers which are capable of being used as thermoplastic polyolefins just as they emerge from the reactor system described, without further compounding of components which substantially modify the physical properties of the polymers, as such compounding is required of polymers of the prior art. Polymers according to the invention unexpectedly possess both low temperature ductility and high flexural modulus, which properties were related in inverse proportion to one another in the polymers of the prior art.

Abstract: Solid fine particles which contain a magnesium atom, an aluminum atom and a C1-20 alkoxy group simultaneously, are insoluble in a hydrocarbon solvent, and have an average particle diameter of 3 to 80 ?m, and an olefin polymerization catalyst containing the solid fine particles and a transition metal compound in the groups 3 to 11 in the periodic table, exhibit a very high olefin polymerization activity without combination with an expensive organoaluminum oxy compound or organoboron compound and maintains a high activity in polymerization for a long time, and an olefin polymer excellent in powdery properties can be produced by using the olefin polymerization catalyst. The transition metal compound in the groups 3 to 11 in the periodic table includes a transition metal compound having a ligand containing two or more atoms selected from a boron atom, a nitrogen atom, an oxygen atom, a phosphorus atom and a sulfur atom.

Abstract: Disclosed is a catalyst for olefin polymerization comprising [I] a solid titanium catalyst component [S] comprising titanium, magnesium, halogen and an electron donor (b), which is obtained by bringing a solid adduct consisting of a magnesium compound and an electron donor (a) into contact with an electron donor (b) and a liquid titanium compound by at least one method selected from (A) a method of contacting the materials in a suspended state in the coexistence of an inert hydrocarbon solvent and (B) a method of contacting the material plural times individed portions and [II] an organometallic compound catalyst component [M] containing a metal selected from the groups I to III in the periodic table.

Abstract: It has been discovered that using n-butylmethyldimethoxysilane (BMDS) as an external electron donor for Ziegler-Natta catalysts can provide a catalyst system that may prepare polypropylene films with improved properties. The catalyst systems of the invention provide for controlled chain defects/defect distribution and thus a regulated microtacticity. Consequently, the curve of storage modulus (G?) v. temperature is shifted such that the film achieves the same storage modulus at a lower temperature enabling faster throughput of polypropylene film through a high-speed tenter.

Abstract: A solid, hydrocarbon insoluble catalyst composition comprising: A) a solid, particulated complex comprising moieties of at least magnesium, a Group 4 transition metal, and a halide; B) one or more ?-amino-substituted- or ?-imino-substituted-2-alkylpyridine compounds; C) one or more organoaluminum cocatalyst compounds; D) optionally one or more internal electron donors; and E) optionally one or more selectivity control agents, a method of preparation and a method of use in polymerizing olefins is disclosed.

Abstract: Disclosed are catalyst systems and methods of making the catalyst systems/supports for the polymerization of polyethylene containing a solid titanium catalyst component containing a titanium compound and a support made from a magnesium compound, an alkyl silicate, and a monoester. The catalyst system may further contain an organoaluminum compound. Also disclosed are methods of making various types of polyethylene involving polymerizing ethylene in the presence of hydrogen and a catalyst system containing a support made from a magnesium compound, an alkyl silicate and a monoester.

Abstract: A catalyst for olefin polymerization comprising (A) a solid catalyst component which is 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 formula R1pAlQ3-p, and (C) an organosilicon compound of the formula SiR2R3(OR4)(OR5), and (D) an organosilicon compound of the formula R6xSi(OR7)4-x exhibits a higher hydrogen activity than conventional catalysts.

Abstract: Process for the polymerization of olefins CH2?CHR, in which R is hydrogen or a hydrocarbon radical with 1–12 carbon atoms, carried out in the presence of a catalyst component (A) comprising Mg, Ti and halogen as essential elements and of a catalyst component (B) capable to produce, under the same polymerization conditions, a polymer with an average particle size lower than that obtainable with the said catalyst component A. The said process provides polymers with increased bulk density.

Abstract: Bimetallic catalyst for producing polyethylene resins with a bimodal molecular weight distribution, its preparation and use. The catalyst is obtainable by a process which includes contacting a support material with an organomagnesium component and carbonyl-containing component. The support material so treated is contacted with a non-metallocene transition metal component to obtain a catalyst intermediate, the latter being contacted with an aluminoxane component and a metallocene component, This catalyst may be further activated with, e.g., alkylaluminum cocatalyst, and contacted, under polymerization conditions, with ethylene and optionally one or more comonomers, to produce ethylene homo- or copolymers with a bimodal molecular weight distribution and improved resin swell properties in a single reactor. These ethylene polymers are particularly suitable for blow molding applications.

Abstract: It has been discovered that using n-butylmethyldimethoxysilane (BMDS) as an external electron donor for Ziegler-Natta catalysts can provide a catalyst system that may prepare polypropylene films with improved properties. The catalyst systems of the invention provide for controlled chain defects/defect distribution and thus a regulated microtacticity. Consequently, the curve of storage modulus (G?) v. temperature is shifted such that the film achieves the same storage modulus at a lower temperature enabling faster throughput of polypropylene film through a high-speed tenter.

Abstract: A process for the (co) polymerization of olefins of formula CH2?CHR wherein R is a hydrogen atom, a methyl or an ethyl radical, carried out in the presence of a system comprising (a) solid catalyst component comprising a compound of Ti or V not containing Metal-? bonds, Mg, halogen and optionally an electron donor compound; (b) an Al-alkyl compound; and (c) one or more non-polymerizing olefins in an amount up to 1.2% by mol with respect to the total olefins present in the reactor.

Abstract: A solid catalyst component for olefin polymerization in which the molar ratio of residual alkoxy groups to supported titanium is 0.60 or less is obtained by reacting the following compound (a1) with the following compound (b1) at a hydroxyl group/magnesium molar ratio of 1.0 or more, reacting the reaction mixture with the following compound (c1) at a halogen/magnesium molar ratio of 0.20 or more, reacting the resultant reaction mixture with the following compounds (d1) and (e) at a temperature of 120° C. or higher but 150° C.

Abstract: A method for polymerization and copolymerization of ethylene is disclosed. The polymerization is carried out in the presence of a preactivated titanium solid complex catalyst supported on a carrier containing magnesium. The resulting polymers have the advantage of high bulk density and broad molecular weight distribution.

Abstract: The present invention relates to a solid catalyst component for the polymerization of olefins CH2?CHR in which R is hydrogen or a hydrocarbon radical with 1–12 carbon atoms, comprising Mg, Ti, halogen and an electron donor selected from maleates of a particular formula. Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give polymers in high yields and with high isotactic index expressed in terms of high xylene insolubility.

Abstract: The invention relates to a method for producing a poly-1-olefin by polymerisation of a 1-olefin of the formula R4CH?CH2, in which 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 0.5 to 50 bar, in the presence of a catalyst which consists of the product of the reaction of a magnesium alkoxide with a transition-metal compound (component a) and an organometallic compound (component b), whose component a has been produced by reacting a transition-metal compound of titanium, zirconium, vanadium or chromium with a gelatinous dispersion of the magnesium alkoxide in an inert hydrocarbon.

Abstract: A solid catalyst component useful for the (co)-polymerization of olefins is disclosed. The catalyst component is prepared by reacting an activated magnesium halide composite support with a halogenized transition metal compound and a chelating diamide compound in the presence of organo-magnesium as a promoting agent and halogenized silicon or boron compounds as an activator. The catalyst component can be used with an organo-aluminum compound to provide a solid catalyst system that is compatible with slurry and gas phase polymerization processes. Linear low density polyethylene (LLDPE) produced using the catalyst component of the present invention displays a low molecular weight distribution, improved co-monomer incorporation, low content of the low molecular weight component, and excellent morphological properties such as spherical shape and high bulk density.

Abstract: A spray-dried catalyst precursor composition and method of making a spray-dried catalyst precursor composition with an inert filler, magnesium, a transition metal, solvent, and one electron donor compound. The catalyst precursor composition is substantially free of other electron donor compounds, the molar ratio of the electron donor compound to magnesium is less than or equal to 1.9, and comprises spherical or substantially spherical particles having a particle size of from about 10 to about 200 ?m. Catalysts made from the spray-dried catalyst precursors and polymerization methods using such catalysts are disclosed.

Abstract: A catalyst solid for olefin polymerization comprising A) at least one magnesium halide, B) at least one metallocene complex and C) at least one compound capable of forming metallocenium ions, is prepared by i) firstly preparing finely divided support particles consisting of the magnesium halide A) and an C1-C8-alcohol having a mean particle diameter of from 1 to 200 ?m from an adduct of the magnesium halide A) and a C1-C8-alcohol, where the adduct contains from 1.5 to 5 mol of the C1-C8-alcohol per mole of magnesium halide, ii) then depositing the compound C) capable of forming metallocenium ions on the finely divided support particles and iii) subsequently bringing the reaction product hereby obtained into contact with the metallocene complex B). This catalyst solid can be used for the polymerization or copolymerization of olefins.

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: 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 method for producing propylene polymers having a broad molecular weight distribution (MWD) is disclosed. The method uses a Ziegler catalyst and one silane donor. The silane donor is selected from vinyltrimethoxysilane or dicyclohexyldimethoxysilane. The polymers made by the method have an MWD greater than or equal to 7.0.

Abstract: Disclosed is a preparation method of titanium catalyst for olefin polymerization, the method comprising (1) preparing magnesium compound solution by resolving non-deoxidative magnesium halide and IIIA group atom compound in a solvent mixture of cyclic ether, at least one alcohol, phosphorus compound and organosilane with or without hydrocarbon solvent; (2) reacting said magnesium compound solution with titanium compound, silicon compound, tin compound or mixture thereof to produce a support; and (3) reacting said support with titanium compound and electron donor to produce solid complex titanium catalyst, wherein the particle size and particle size distribution f said catalyst are regulated by controlling solubility of the reactants in said steps (2) and/or (3).

Abstract: The present invention concerns high-stiffness polymer composition and a process for producing a polymer composition by nucleated with a polymeric nucleating agent containing vinyl compound units. The method comprises modifying a catalyst by polymerizing a vinyl compound in the presence of said catalyst and a strongly coordinating donor in a medium, which does not essentially dissolve the polymerized vinyl compound, and by continuing the polymerization of the vinyl compound until the concentration of unreacted vinyl compounds is less than about 0.5 wt-%. The thus obtained modified catalyst composition is used for polymerizing propylene optionally together with comonomers in the presence of said modified catalyst composition. Modification of the catalyst according to the present invention will reduce production costs and provide highly reliable catalyst activity and polymers of high stiffness.

Abstract: The present invention relates to catalysts particularly suitable for the sterospecific polymermerization of olefins, comprising Ti, Mg, halogen and an electron donor compound selected from heteroatoms containing esters of malonic acids. Polymers produced by the catalysts have high isotactic index expressed in terms of high xylene insolubility.

Abstract: The present invention relates to a process for the polymerization of olefins using catalyst components and catalysts obtained therefrom comprising Ti, Mg, halogen and an electron donor compound selected from heteroatoms containing esters of malonic acids. The catalysts are particularly suitable for the sterospecific polymermerization of olefins having high isotactic index expressed in terms of high xylene insolubility.

Abstract: The present invention relates to catalyst components for the polymerization of olefins, and to the catalyst obtained therefrom, particularly suitable for the stereospecific polymerization of olefins, comprising Ti, Mg, halogen and an electron donor compound selected from heteroatom containing esters of malonic acids (heteroatom containing malonates). Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give polymers in high yields and with high isotactic index expressed in terms of high xylene insolubility.

Abstract: The present invention relates to catalyst components for the polymerization of olefins, and to the catalyst obtained therefrom, particularly suitable for the stereospecific polymerization of olefins, comprising Ti, Mg, halogen and an electron donor compound selected from heteroatom containing esters of malonic acids (heteroatom containing malonates). Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give polymers in high yields and with high isotactic index expressed in terms of high xylene insolubility.

Abstract: The invention relates to an improved olefin catalyst, a method of in situ-activated catalyst preparation and a process for the polymerization of olefinic monomers via, for example, a titanium trichloride/magnesium dichloride/tetrahydrofuran reaction product catalyst precursor. The activated catalyst is prepared in situ in a polymerization reactor using an alumoxane based co-catalyst wherein the cumbersome traditional steps of catalyst activation and isolation, prior to polymerization are eliminated. An unexpected advantage of this invention is a significant increase in catalyst productivity while maintaining a relatively constant value of the bulk density of polymeric materials produced while concomitantly producing a polymeric product having a broad molecular weight distribution compared with typical alumoxane-activated metallocene catalysts.

Abstract: Disclosed are a propylene polymer having a high crystallinity of a boiled heptane-insoluble component contained therein, a high stereoregularity and an extremely long mesochain (continuous propylene units wherein directions of {acute over (&agr;)}-methyl carbons are the same as each other), and a process for preparing said polymer. Further disclosed is a propylene polymer composition comprising the above propylene polymer and at least one stabilizer selected from a phenol type stabilizer, an organophosphite type stabilizer, a thioether type stabilizer, a hindered amine type stabilizer a metallic salt of higher aliphatic acid. The propylene block polymer of the invention is well-balanced between rigidity, heat resistance and moisture resistance, and can be favorably used for sheet, filament, injection molded product, blow molded product, etc.

Abstract: The present invention relates to catalyst components for the polymerization of olefins, and to the catalyst obtained therefrom, particularly suitable for the stereospecific polymerization of olefins, comprising Ti, Mg, halogen and an electron donor compound selected from heteroatom containing esters of malonic acids (heteroatom containing malonates). Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give polymers in high yields and with high isotactic index expressed in terms of high xylene insolubility.

Abstract: The invention relates to an improved olefin catalyst, a method of in situ-activated catalyst preparation and a process for the polymerization of olefinic monomers via, for example, a titanium trichloride/magnesium dichloride/tetrahydrofuran reaction product catalyst precursor. The activated catalyst is prepared in situ in a polymerization reactor using an alumoxane based co-catalyst wherein the cumbersome traditional steps of catalyst activation and isolation, prior to polymerization are eliminated. An unexpected advantage of this invention is a significant increase in catalyst productivity while maintaining a relatively constant value of the bulk density of polymeric materials produced while concomitantly producing a polymeric product having a broad molecular weight distribution compared with typical alumoxane-activated metallocene catalysts.

Abstract: The present invention is generally directed to a process for preparing aromatic polymers. It further relates to devices that are made with the polymers.

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: The invention is directed to olefin polymerization processes using bridged hafnocene catalyst complexes comprising highly substituted noncoordinating anions that are surprisingly stable under high temperature olefin polymerization processes such that olefin copolymers having significant amount of incorporated comonomer can be prepared with high molecular weights. More specifically, the invention is a polymerization process for ethylene copolymers having a melt index of about 0.87 to about 0.930 comprising contacting, under homogeneous polymerization conditions at a reaction temperature at or above 140° C. to 225° C.

Abstract: Disclosed are a propylene polymer having a high crystallinity of a boiled heptane-insoluble component contained therein, a high stereoregularity and an extremely long mesochain (continuous propylene units wherein directions of &agr;-methyl carbons are the same as each other), and a process for preparing said polymer. Also disclosed are a propylene block copolymer containing a crystalline polypropylene portion having a high crystallinity of a boiled heptane-insoluble component contained therein, a high stereoregularity and an extremely long mesochain, and a process for preparing said copolymer. Further disclosed is a propylene polymer composition comprising the above propylene polymer or propylene block copolymer and at least one stabilizer selected from a phenol type stabilizer, an organophosphite type stabilizer, a thioether type stabilizer, a hindered amine type stabilizer and a metallic salt of higher aliphatic acid.

Abstract: A method of making a solid procatalyst composition for use in a Ziegler-Natta olefin polymerization catalyst composition, said method comprising:

Abstract: Catalyst-forming components and catalysts for the polymerization of olefins based on said components are disclosed. The catalysts comprise the reaction product of: (a) an Al alkyl compound; (b) a silicon compound containing at least a Si—OR or Si—OCOR or Si—NR2 bond, R being a hydrocarbyl radical; and (c) a solid comprising, as essential support, a Mg dihalide in active form and, supported thereon, a Ti halide or a halo-Ti-alcoholate or said halogenated Ti compound and a silicon compound as defined in (b) in a molar ratio with the supported Ti compound from 1.0 mole to 5 moles of silicon compound per mole of Ti 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 to the catalysts obtained from said components.

Abstract: The invention is directed to a process for the preparation of a catalyst component for the polymerization of an olefin by:

Abstract: Processes for the polymerization of olefins with Zeigler-type catalyst systems which involve transition metal catalyst components comprising 4, 5 or 6 transition metals incorporating internal electron donors to provide desired polymerization characteristics, including yield and polymer characteristics. Specific olefins used in the polymerization process are C2-C4 alpha olefins such as propylene in the production of stereoregular polypropylene. The catalyst system comprised a transition metal component having an internal electron donor in an amount providing an internal donor/transition metal mole ratio of no more than 2/3. This is combined with an organoaluminum co-catalyst component to provide a precusor mixture having an aluminum/transition metal mole ration of at least 100. The precusor mixture is combined with an organosilicon external electron donor component in an amount to provide an aluminum/silicon mole ration of no more than 200.

Abstract: A Ziegler-Natta type catalyst having an improved hydrogen response provides for narrowing of the MWD of resulting polyolefins polymerized using such catalyst, with such catalyst generally made by a) contacting a soluble magnesium dialkoxide compound of the general formula Mg(OR″)2 with a halogenating agent capable of exchanging one halogen for one alkoxide to form a reaction product A, where R″ is a hydrocarbyl or substituted hydrocarbyl having from 1 to 20 carbon atoms; b) contacting reaction product A with a first halogenating/titanating agent to form reaction product B; and c) contacting reaction product B with a second halogenating/titanating agent to form a catalyst component; wherein in at least one of steps b) and c), the halogenating/titanating agent is a blend of Ti(OPr)4 and TiCl4. Catalyst components, catalysts, catalyst systems, polyolefin polymers, and methods of forming each are disclosed.

Abstract: An olefin polymerization process is described. The process comprises polymerizing an olefin in the presence of a support, a single-site catalyst, an optional activator, and a fatty amine. The support is chemically treated with an organoboron compound. The single-site catalyst contains a polymerization-stable, heteroatomic ligand. The fatty amine is added directly to the reactor. The combination of pre-treating the support with an organoboron compound and the addition of fatty amine to the process unexpectedly increases catalyst activity.

Abstract: A process is provided which comprises preparing an olefin oligomerization or trimerization catalyst system and producing olefins in the presence of the olefin oligomerization or trimerization catalyst system and a solvent, wherein said catalyst system preparation comprises the steps of first contacting a chromium source and a pyrrole-containing compound to form a chromium/pyrrole mixture; second, contacting said chromium/pyrrole mixture with a metal alkyl to form a catalyst system; and then contacting said catalyst system with an alpha-olefin, preferably ethylene.

Abstract: The present invention relates to a solid catalyst component for &agr;-olefin polymerization having a narrow particle size distribution of not less than 6.0 in terms of the value of N in a Rosin-Rammler function of particle size distribution and giving a catalytic activity of not less than 10,000 ((g-polymer produced/g-solid catalyst component)/hour) in polymerization. According to the present invention, there can be provided a solid catalyst component for &agr;-olefin polymerization capable of giving a poly-&agr;-olefin having the high bulk density and favorable particle properties with high catalytic activity.

Abstract: Process for producing a propylene/1-pentene polymer in the presence of a Ziegler-Natta catalyst system with the monomer reactants being in the vapor phase while the reaction is in process and with no liquid component being present in the reaction zone while the reaction is in progress. Different ways of introducing the reactants are disclosed (partly in liquid phase then immediately evaporated or not, preheated or not, mixed with the comonomer or not).

Abstract: The present invention relates to a process to produce polyethylene through homopolymerization or copolymerization of ethylene with alpha-olefins in the presence of a titanium amide catalyst supported by an organic polymer material, for the production of moldings, such as through extrusion, injection molding, film blowing, sintering under pressure or ram extrusion. The catalyst according to the present invention contains a partially chloromethylated styrene divinyl benzene copolymer as the organic polymer material, a complex compound supported by it, which contains Mg, Al and Ti.

Abstract: A method of polymerizing olefins with a catalyst component which comprises 1) the reaction product of a magnesium alkoxide of the formula M(OR)2, wherein M is magnesium, O is oxygen, R is a hydrocarbyl having from 1 to 20 carbons atoms, and a halogenating agent; 2) an electron donor wherein the electron donor is diethyl phthalate or di-isobutyl phthalate; 3) a titanating agent. The catalyst component is activated with an organoaluminum cocatalyst. An external donor, specifically dicyclopentyl dimethoxysilane or cyclohexylmethyldimethoxy silane, can be added as a stereoselectivity control agent. The activated catalyst is used in the polymerization of olefins, particularly propylene, to obtain a polymer product with a broad molecular weight distribution.

Abstract: A process for producing an olefin polymer using a catalyst in which (A) is a solid catalyst component which includes magnesium, titanium, halogen and an electron donative compound as essential constituents; (B) is an organoaluminum component; and (C) is at least two electron donative compounds (&agr;) and (&bgr;), wherein the pentad stereoregularity of a xylene insoluble fraction of a homopolyproylene is 0<mmrr/mmmm≦0.0068 when electron donative compound (&agr;) is used in combination with (A) and (B), and the pentad stereoregularity of a xylene insoluble fraction homoproplyene of a is 0.0068<mmrr/mmmm ≦0.0320 when electron donative compound (&bgr;) is used in combination with (A) and (B). A polypropylene produced in the process can be used to obtain a biaxially oriented film. (A) and (B). A polypropylene produced in the process can be used to obtain a biaxially oriented film.

Abstract: A method for producing a polyolefin in the presence of a catalyst comprising a transition metal compound and an organometallic compound, wherein a catalyst system is used which comprises (A) a solid catalyst component prepared by reacting a homogeneous solution containing (I) at least one member selected from the group consisting of metal magnesium and a hydroxylated organic compound, and oxygen-containing organic compounds of magnesium, (II) at least one zirconium compound selected from the group consisting of oxygen-containing organic compounds and halogen-containing compounds of zirconium, and (III) at least one silicon compound selected from the group consisting of polysiloxanes and silanes, with (IV) at least one organoaluminum halide compound to obtain a solid product, isolating the solid product, and reacting this solid product with (V) at least one halogen-containing compound of titanium, and (B) at least one catalyst component selected from the group consisting of organoaluminum compounds.

Abstract: The present invention relates to polybutene-1 homopolymers, or copolymers containing up to 20% by weight of alpha olefins having from 2 to 10 carbon atoms other than butene-1, characterized by the following properties: (i) an isotactic index (mmmm %), measured by NMR analysis according to the method specified below, of higher than 93; (ii) a Molecular Weight Distribution (MWD) in terms of Mw/Mn, measured by GPC analysis according to the method specified below, of higher than 6; and (iii) a content of catalytic residues expressed in terms of Ti ppm of lower than 50. Said polymers are very suitable for the preparation of articles, in particular pipes, having improved creep and burst stress resistance.