Abstract: A process for preparing a polydiene, the process comprising the step of: polymerizing conjugated diene monomer in the presence of a (hydrocarbyloxyhydrocarbyl)amine, where said step of polymerizing employs a lanthanide-based catalyst system.

Abstract: A process for preparing a polydiene, the process comprising the step of polymerizing conjugated diene monomer with a nickel-based catalyst system, where said step of polymerizing takes place within a polymerization mixture that includes less than 20% by weight of organic solvent based on the total weight of the polymerization mixture, where the temperature of the polymerization mixture is maintained below 34° C. during said step of polymerizing, and where the conversion of the conjugated diene monomer is maintained below 30%.

Abstract: A cross-linkable resin shaped article which contains a heat curable resin, cross-linking agent, and condensed aromatic polycyclic compound which has a (meth)acryloyloxy group, a cross-linked resin shaped article which is comprised of that cross-linkable resin shaped article which is cross-linked, and a laminate which is obtained by using these are provided. The cross-linkable resin shaped article and cross-linked resin shaped article of the present invention are excellent in heat resistance and further are useful in production of a low linear expansion laminate.

Abstract: The present invention comprises a molding composition comprising at least about 70% wt. polypropylene or polypropylene random copolymer; up to about 30 wt. % of a block copolymer composition comprising at least one selectively hydrogenated block copolymer which substantially matches the index of refraction of the polypropylene or polypropylene random copolymer, and up to about 0.70% by wt. of a clarifying agent, wherein the weight % of the total blend is 100%. The present invention also may be a molded article produced from the molding composition. A molded article formed from such a composition at a thickness of 0.125 inches will have a haze of less than about 50% and an instrumented impact toughness of at least 100 inch-lbs at ?20° C. to ?30° C.

Abstract: A process for introducing a catalyst powder based on a titanium compound supported on magnesium halide into a gas-phase olefin polymerization reactor, characterized in that it comprises: (a) storing the catalyst powder under an atmosphere of a liquid C3-C12 alkane; (b) withdrawing from step (a) a measured amount of said catalyst powder by means of a rotary valve; (c) transferring said metered amount of catalyst powder to a catalyst activation section by a continuous pick-up flow of a liquid C3-C12 alkane; (d) contacting the catalyst powder with a liquid phase comprising an organo-aluminum compound and optionally an external donor compound, at a temperature ranging from ?20° C. to 60° C.; (e) introducing the activated catalyst powder in one or more gas-phase olefin polymerization reactors, where a gaseous mixture comprising at least one alpha-olefin is subjected to polymerization.

Abstract: A method for polymerizing conjugated diene monomer into polydienes, the method comprising: polymerizing conjugated diene monomer within a liquid-phase polymerization mixture that includes conjugated diene monomer, a lanthanide-based catalyst system, dicyclopentadiene or substituted dicyclopentadiene, and optionally organic solvent, with the proviso that the organic solvent, if present, is less than about 20% by weight based on the total weight of the polymerization mixture.

Abstract: A polymerizable composition suitable as an electric material and the like used in an electric circuit board, which comprises a norbornene monomer, a metathesis polymerization catalyst, and a chain transfer agent composed of a compound represented by formula (A): CH2?CH—Y—OCO—CR1?CH2 wherein Y represents a divalent hydrocarbon group having 3 to 20 carbon atoms, and R1 represents a hydrogen atom or a methyl group. By further comprising a crosslinking agent in the polymerizable composition, obtaining a crosslinkable resin by carrying out bulk polymerization, and crosslinking the crosslinkable resin to obtain a molded article and a crosslinked resin composite having excellent characteristics such as electric insulation, adhesion, mechanical strength, heat resistance, dielectric properties and the like.

Abstract: Provided are bulk homogeneous polymerization processes for producing ethylene propylene random copolymers. The process includes contacting in a reactor or in a series of reactors propylene monomer, ethylene comonomer with one or more catalyst systems and optional solvent (present at less than 40 wt %), wherein the reactor train is at a temperature of between 65° C. and 180° C.

Abstract: A method for quenching an active polymerization mixture, the method comprising introducing a polyhydroxy compound to an active polymerization mixture.

Abstract: A process for preparing a polydiene, the process comprising the step of polymerizing conjugated diene monomer in the presence of a dihydrocarbyl ether, where said step of polymerizing takes place within a polymerization mixture that includes less than 20% by weight of organic solvent based on the total weight of the polymerization mixture, and where said step of polymerizing employs a lanthanide-based catalyst system that includes the combination of or reaction product of ingredients including (a) a lanthanide compound, (b) an aluminoxane, (c) an organoaluminum compound other than an aluminoxane, and (d) a bromine-containing compound selected from the group consisting of elemental bromine, bromine-containing mixed halogens, and organic bromides.

Abstract: A method for polymerizing conjugated diene monomer into polydienes, the method comprising: polymerizing conjugated diene monomer within a liquid-phase polymerization mixture that includes conjugated diene monomer, a lanthanide-based catalyst system, dicyclopentadiene or substituted dicyclopentadiene, and optionally organic solvent, with the proviso that the organic solvent, if present, is less than about 20% by weight based on the total weight of the polymerization mixture.

Abstract: The present invention relates to a supported catalyst composition and a method for making the supported catalyst composition and its use in a process for polymerizing olefin(s). In particular, the invention is directed to a method for making a supported catalyst composition by contacting a supported activator with a bulky ligand and a metal compound.

Abstract: The present invention relates to a process for preparing an activating support for metallocene complexes in the polymerisation of olefins comprising the steps of: I) providing a support prepared consisting in particles formed from at least one porous mineral oxide; II) optionally fixing the rate of silanols on the surface of the support; III) functionalising the support with a solution containing a fluorinated functionalising agent; IV) heating the functionalised and fluorinated support of step c) under an inert gas and then under oxygen; V) retrieving an active fluorinated support. That activating support is used to activate a metallocene catalyst component for the polymerisation of olefins.

Abstract: A process for preparing a polydiene, the process comprising the step of polymerizing conjugated diene monomer in the presence of a dihydrocarbyl ether, where said step of polymerizing employs a lanthanide-based catalyst system.

Abstract: A synthesis process of trans-1,4-polyisoprene, using bulk precipitation polymerization of isoprene catalyzed by supported titanium catalyst TiCl4/MgCl2. The process includes prepolymerizing carried out in a prepolymerization reactor with an anchor agitator; polymerizing carried out in a polymerization reactor with a helical ribbon agitator; and devolatilizing and drying carried out in a vacuum rake dryer. Not only does the process require lower energy consumption and thus a lower production cost, but it also eliminates the emission of three wastes.

Abstract: This invention is concerned with a butadiene-based polymer having a high cis-1,4 bond content, a low vinyl bond content and a molecular weight distribution of a specified range, and more particularly a butadiene-based polymer having a 1,3-butadiene monomer unit, characterized in that a cis-1,4 bond content and a vinyl bond content in the 1,3-butadiene monomer unit as measured by a Fourier transform infrared spectroscopy (FT-IR) is not less than 98.0% and not more than 0.3%, respectively, and a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) is 1.6-3.5.

Abstract: A method for the continuous production of polydienes, the method comprising the steps of (a) charging a mixture of one or more monomer, catalyst system, and less than 50% weight percent organic solvent based on the total weight of the monomer, catalyst and solvent, into first vessel, (b) polymerizing the monomer to a conversion of up to 20% by weight of the monomer to form a mixture of reactive polymer and monomer, (c) removing the mixture of reactive polymer and monomer from the vessel, and (d) terminating the reactive polymer prior to a total monomer conversion of 25% by weight.

Abstract: The invention relates to a process for the production of post-crosslinkable thermoplastic resins by bulk-polymerizing a polymerizable composition (A) comprising (I) a monomer fluid containing a cyclic olefin (?) having two or more metathetical ring-opening reaction sites in the molecule in an amount 10 wt % or above based on the total amount of the monomers or a monomer fluid containing a norbornene monomer and a crosslinking agent, (II) a metathetical polymerization catalyst, and (III) a chain transfer agent; thermoplastic resins obtained by this process; and a process for producing crosslinked resins or crosslinked resin composite materials which comprises laminating such a thermoplastic resin with a substrate at need and then crosslinking the thermoplastic resin. According to the invention, thermoplastic resins which are free from odor due to residual monomers and excellent in storage stability can be efficiently obtained by a simple process of bulk-polymerizing the composition (A).

Abstract: The invention relates to a process for the production of post-crosslinkable thermoplastic resins by bulk-polymerizing a polymerizable composition (A) comprising (I) a monomer fluid containing a cyclic olefin (?) having two or more metathetical ring-opening reaction sites in the molecule in an amount 10 wt % or above based on the total amount of the monomers or a monomer fluid containing a norbornene monomer and a crosslinking agent, (II) a metathetical polymerization catalyst, and (III) a chain transfer agent; thermoplastic resins obtained by this process; and a process for producing crosslinked resins or crosslinked resin composite materials which comprises laminating such a thermoplastic resin with a substrate at need and then crosslinking the thermoplastic resin. According to the invention, thermoplastic resins which are free from odor due to residual monomers and excellent in storage stability can be efficiently obtained by a simple process of bulk-polymerizing the composition (A).

Abstract: A method for the continuous production of polydienes, the method comprising the steps of (a) charging a mixture of one or more monomer, catalyst system, and less than 50% weight percent organic solvent based on the total weight of the monomer, catalyst and solvent, into first vessel, (b) polymerizing the monomer to a conversion of up to 20% by weight of the monomer to form a mixture of reactive polymer and monomer, (c) removing the mixture of reactive polymer and monomer from the vessel, and (d) terminating the reactive polymer prior to a total monomer conversion of 25% by weight.

Abstract: Provided is a method of preparing styrene polymers, the method comprising: homogeneously mixing a styrene monomer; a cocatalyst mixture of Group 13 metal-containing organic metal compound cocatalyst and an inert organic solvent; and a catalyst mixture of a metallocene catalyst and the inert organic solvent using a high speed homogenizing mixer to obtain a homogenized mixture; and providing the homogenized mixture to a reactor to initiate polymerization. In this method, catalyst is quickly dispersed among monomers using a high speed homogenizing mixer so that formation of gel, which occurs when a syndiotactic styrene polymer is produced, can be fundamentally prevented. In addition, a styrene polymer prepared using the method has high activity, good stereoregularity, and uniform molecular distribution.

Abstract: There is provided a synthetic resin emulsion comprising polymer particles having a core/shell structure, wherein the shell comprises a copolymer of an unsaturated carboxylic acid and a hydrophilic comonomer, the core comprises a copolymer of a monomer mixture comprising a radically polymerizable main monomer and a radically polymerizable functional monomer, and the monomers constituting the monomer mixture are selected so that the glass transition point (Tg) of the copolymer produced by polymerization is ?20° C. or below, and the synthetic resin emulsion has been produced by adding the monomer mixture for core formation and a pH adjustor to an aqueous copolymer solution, which has not been neutralized, produced by polymerizing the unsaturated carboxylic acid and the hydrophilic comonomer in an aqueous medium, and allowing a polymerization reaction to proceed.

Abstract: A crosslinkable resin composition is provided which can be a forming material having excellent adhesion to metals and excellent heat resistance. The crosslinkable resin composition comprises; a cycloolefin resin (A) obtained through metathesis polymerization of a cycloolefin monomer in the presence of a compound having two or more vinyl groups in the molecule, and a radical generating agent (B). A crosslinked resin molded product is obtained by crosslinking such a crosslinkable resin composition through heating.

Abstract: The present invention relates to a supported catalyst composition and a method for making the supported catalyst composition and its use in a process for polymerizing olefin(s). In particular, the invention is directed to a method for making a supported catalyst composition by contacting a supported activator with a bulky ligand and a metal compound.

Abstract: The present invention relates to a fiber coated with a water blocking material that includes an essentially water free dispersion comprising a superabsorbent polymer and a dispersing medium. The fibers made according to this invention may be used, for example, as fiber reinforcing material used in the manufacture of cables, and in particular in yarns for fiber optical cables that use optical light wave guides for optical communication transmissions.

Abstract: The present invention provides a catalyst for bulk or vapor-phase polymerization having high polymerization activity during bulk or vapor-phase polymerization and providing an olefin polymer having excellent properties in melt flow rate and stereoregularity by adding a small amount of hydrogen. The catalyst for bulk or vapor-phase polymerization of an &agr;-olefin compound under a presence of hydrogen, the catalyst is made by contacting the following ingredients (A) to (C). (A) a solid catalyst ingredient, comprising: (a) a magnesium compound, (b) titanium tetrachloride, and (c) dialkyl phthalate (Each of the alkyl group denotes a straight-chain or branched-chain hydrocarbon group having a carbon number of 3 to 20.); (B) an organoaluminum compound; and (C) an organosilicon compound, which is expressed by the following general chemical formula (1).

Abstract: An in-situ method for performing organic metathesis polymer chemistry in the solid state includes the step of providing an organic monomer and a catalyst, the catalyst for driving a metathesis polymerization reaction of the monomer. The organic monomer can be provided as a liquid monomer. The reaction produces reaction products including a polymeric end product and at least one volatile reaction product. At least a portion of the volatile reaction product is removed during the reaction to favor formation of the reaction product. Significantly, the reaction is performed at a temperature being below an average melting point of the polymeric end product such that at least a portion of the reaction is performed in the solid phase.

Abstract: A stable continuous production of a propylene-based block copolymer can proceed for a long time without causing accumulation of particles having a small diameter by a process having the following steps: (1) polymerizing an &agr;-olefin containing liquid propylene as a main component in the presence of hydrogen and a stereoregular polymerization catalyst in one or more polymerization reactors to obtain a polymer slurry; (2) feeding the polymer slurry to a copolymerization reactor; and (3) copolymerizing propylene and an &agr;-olefin other than propylene substantially in a gaseous phase in the presence of the stereoregular polymerization catalyst, the polymer slurry and a deactivating compound in the copolymerization reactor to obtain a propylene-block copolymer powder.

Abstract: A process for preparing aqueous polymer dispersions comprises first of all subjecting ethylenically unsaturated monomers to free-radical aqueous emulsion polymerization to prepare an aqueous dispersion of a polymer 1 having a glass transition temperature Tg1, then dissolving further, comparatively hard monomers in the dispersed particles of the polymer 1, and subsequently carrying out free-radical polymerization of said monomers dissolved in said particles.

Abstract: A drag-reducing polymer is described, along with a method for manufacturing the drag-reducing polymer. The drag-reducing polymer is manufactured by bulk polymerizing a vinyl aromatic with an &agr;-olefin, wherein the &agr;-olefin has a carbon chain length of between two and twenty carbons. A drag-reducing polymer suspension and drag-reducing polymer solution are also described.

Abstract: The present invention is a nanocomposite which is a dispersion of nanofiller particles derived from layered metal oxides or metal oxide salts. The nanocomposite is advantageously prepared by first swelling an untreated clay in water, then removing the water to form an organophilic clay that is dispersible in non-polar organic solvents. The organophilic clay can then be treated with an alkyl aluminoxane and subsequently a catalyst to form a complex that promotes olefin or styrenic polymerization and platelet dispersion. The nanocomposite can be prepared directly by in situ polymerization of the olefin or the styrene at the nanofiller particles without shear, without an ion exchange step, and without the need to incorporate polar substituents into the polyolefin or polystyrene.

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.

Abstract: The present invention provides methods for obtaining highly stereoregular polyacetylenes from organorhodium catalysts in aqueous media in high yield. These methods afford substantial advantages in that they are rapid, economical, and utilize environmentally benign solvents. The present invention further provides methods for making thin films of polyphenylacetylenes that are tough and transparent.

Abstract: Elastomeric ethylene/propylene or ethylene/propylene/-polyene copolymers containing small amounts of one or more .alpha.-olefins are prepared by a slurry process wherein the polymerization reaction is carried out in a mixture of liquid propylene and alpha-olefin. Problems due to fouling phenomena in the reactor are avoided.

Abstract: Polymers of C.sub.2 -C.sub.12 -alk-1-enes are prepared at from -50 to 300.degree. C. and from 0.5 to 3000 bar in the presence of a catalyst system by a process in which the catalyst system used is one which containsA) an inorganic or organic carrier,B) a metallocene complex,C) a compound forming metallocenium ions andD) if required, a metal compound of the general formula IM.sup.1 (R.sup.1).sub.r (R.sup.2).sub.s (R.sup.3).sub.t IwhereM.sup.1 is an alkali metal, an alkaline earth metal or a metal of main group III of the Periodic Table,R.sup.1 is hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl, alkylaryl or arylalkyl, each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical,R.sup.2 and R.sup.3 are each hydrogen, halogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.

Abstract: A polymeric composition is provided comprising a random copolymer polypropylene, a hydrogenated block copolymer comprising at least two polymeric block containing predominately monoalkenyl aromatic hydrocarbon monomer units and at least one block containing a predominately hydrogenated, conjugated diene unit, and an elastic metallocene-based polyolefin. The polymer has improved impact strength and clarity, particularly at low temperatures.

Abstract: A novel polyphenylene resin is formed by the polycyclotrimerization of vinylethynylbenzene, diethynylbenzene and phenylacetylene. Polymerization is carried out under conditions which result in the retention of unreacted vinyl groups from the vinylethynylbenzene component, which are then susceptible to crosslinking. The polymer is useful in the formation of high-performance carbon-carbon composites, producing an unusually high char yield with advantageous handling and processing characteristics.

Abstract: Disclosed are unsaturated .alpha.-olefin/.alpha., .omega.-diene copolymers, and a method of preparation thereof. The copolymers are generally crystalline, free of gel and cross-links, and contain unsaturated side chains and long chain branching. The copolymers contain up to 5 mole percent diene incorporated therein, and may be prepared by copolymerization using a solid-phase, insoluble coordination catalyst, without a solvent, and below the crystalline melting point of the copolymer.

Abstract: Disclosed are unsaturated .alpha.-olefin/.alpha.,.omega.-diene copolymers, and a method of preparation thereof. The copolymers are generally crystalline, free of gel and cross-links, and contain unsaturated side chains and long chain branching. The copolymers contain up to 5 mole percent diene incorporated therein, and may be prepared by copolymerization using a solid-phase, insoluble coordination catalyst, without a solvent, and below the crystalline melting point of the copolymer.

Abstract: A liquid phase, powder bed polymerization process for preparing syndiotactic polymers of vinylaromatic monomers comprising:A) continuously introducing one or more vinylaromatic monomers and one or more catalyst systems to a horizontally disposed, continuously agitated, cylindrically shaped reactor containing a particulated solid, the contents of which are maintained in an agitated state at a Froude Number in the range from 0.1 to 10, andB) continuously removing polymerized product therefrom.

Abstract: A halogenated aluminum-based cocatalyst provides a metathesis catalyst system with high activity, moisture insensitivity, and long pot lives. The cocatalyst can be employed in solution or in in-mold bulk polymerization processes.

Abstract: High molecular weight syndiotactic polystyrene having greater than 96% syndiotacticity can be produced in very high yield (greater than 92%) by polymerizing styrene monomer, under rigorously anhydrous conditions, with a catalyst comprising Cp*M(CH.sub.3).sub.3, where Cp* is a single .eta..sup.5 -cyclopentadienyl or an .eta..sup.5 -cyclopentadienyl group optionally covalently bonded to M through a substituent, and M is selected from Ti, Zr, Hf and a co-catalyst comprising B(C.sub.6 F.sub.5).sub.3 dissolved in an aromatic solvent such as toluene or styrene, at carefully controlled temperatures in the range -15.degree. C. to +50.degree. C. The rapid rate of polymerization and high yield make the production of hard, rigid products by reaction injection moulding possible.

Abstract: Copolymers of propylene and a non-conjugated diene or triene of the formula (I): CH.sub.2 =CH(CHR.sup.4).sub.n CR.sup.1 =CR.sup.2 R.sup.3, where R.sup.1 and R.sup.2 are hydrogen or alkyl, but are not both hydrogen; R.sup.3 is alkyl or alkenyl of the formula (II): --(CHR.sup.8).sub.m CR.sup.5 =CR.sup.6 R.sup.7, where R.sup.5 and R.sup.6 are as defined for R.sup.1 (above), but are not both hydrogen; R.sup.7 is alkyl; each R.sup.8 is as defined for R.sup.4 (below); and m is 1 to 5; R.sup.4 is hydrogen or alkyl especially methyl; and n is from 2 to 5, can be made using highly stereospecific Ziegler-Natta polymerisation catalysts. The copolymers have 99.9 to 60, particularly 99.5 to 85, mole % propylene residues and 0.1 to 40, particularly 0.5 to 15, mole % diene residues. The copolymers have unexpectedly low solubility in organic solvents such as xylene and can be cross-linked, vulcanised or cured to give polymers having improved high temperature performance.

Abstract: In the case of Ziegler catalysts based on a metallocene as the transition metal component and an aluminoxane as the activator, preactivation of the metallocene with the aluminoxane results in a considerable increase in the activity of the catalyst system. Furthermore, 1-olefin polymers of a high degree of isotacticity and having compact, spherical particles, a very narrow particle size distribution and a high bulk density are obtained by means of a catalyst system of this type.

Abstract: There is disclosed a process for continuously and efficiently producing a styrenic polymer having a high degree of syndiotactic configuration which comprises effecting polymerization reaction by continuously introducing a styrenic monomer and a polymerization catalyst into a polymerization reactor, the inside of which has been brought into fluidized state by particles previously fed therein, which process is characterized in that the polymerization reactor temperature is controlled by vaporizing a part of the styrenic monomer which has been introduced into the polymerization reactor, while the inside of the reactor is maintained under reduced pressure. According to the above process, such problems as difficulty in polymerization reactor scale-up, adhesion of polymer to the reactor inside and polymer particle agglomerate are simultaneously solved, and thereby the industrial significance of the process is remarkably enhanced.

Abstract: Cyclic olefin metathesis polymerization catalyst comprising metal compounds wherein said metals consist essentially of a minor amount of a transition metal which Will initiate ring-opening metathesis polymerization of a cyclic olefin and a major amount of at least one second metal which will propagate the polymerization, wherein said catalyst is essentially devoid of pyrophoric metal compounds, e.g. metal alkyls, and preformed metal carbenes. A preferred transition metal is ruthenium. Said second metal can comprise aluminum, copper, hafnium, iron (III), iridium, manganese, molybdenum, nickel, niobium, rhenium, rhodium, tantalum, titanium, tungsten, yttrium, a Lanthanide, zinc or zirconium or a mixture thereof. Using such catalyst cyclic olefin, e.g. norbornene derivatives, can be polymerized, e.g. in an extruder, even in the presence of water.

Abstract: A reaction solution comprising a mixture of tricyclopentadiene, a norbornene monomer with at least 3 rings in its backbone, a 5-alkenyl-2-norbornene pot life adjusting agent along with a molybdenum type catalyst system gives prolonged pot life without extending time to exotherm (e.g., smoking time). By utilizing this reaction solution it is possible to bulk polymerize reinforced or unreinforced articles in a mold via ring-opening polymerization. Articles so obtained have good outward appearance and excellent physical properties.

Abstract: A polymer of 4-methylpentene-1 having a substantially syndiotactic structure, which polymer contains 0 to 30 mol % of the .alpha.-olefin unit other than the 4-methylpentene-1 unit and has excellent physical properties.

Abstract: Disclosed herein is a method for controlling the molecular weight of a propylene homo- or co-polymer at a constant level upon subjecting propylene alone or a mixture of propylene and another .alpha.-olefin copolymerizable with propylene as a monomer or monomer mixture to bulk polymerization in the presence of hydrogen as a molecular weight modifier in a reaction tank equipped with a reflux condenser.

Abstract: A method for producing a homopolymer or copolymer of an .alpha.-olefin is disclosed, wherein a specific catalyst is used, said catalyst comprising a solid catalyst component obtained by contacting, in the presence of a chlorinated hydrocarbon solvent, a titanium compound and an aromatic carboxylic ester with a solid component obtained by reacting a hydrocarbon solvent-soluble organomagnesium compound having an alkoxy group with a specified chlorosilane compound having an Si--H bond; an organoaluminum compound; and an alkoxysilane compound. By the method of the present invention, an .alpha.-olefin homopolymer or copolymer exhibiting high bulk density and stereoregularity can be efficiently produced under even such polymerization reaction conditions, that the polymerization temperature is high and the polymerization time is long.