Abstract: Disclosed in an olefin polymerization catalyst comprising a transition metal compound having at least two transition metals in which at least one of said metals is bonded to a ligand having a cyclopentadienyl skeleton, at least one of said metals is selected from Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and lanthanoid metals and at least on of the others is selected from the specific transition metals; and an organoaluminum oxy-compound or an organoboron compound. Corresponding to the kind of the metal combined with said metal selected from Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and lanthanoid metals, the olefin polymerization catalyst exhibit a property to give polymers having a wide molecular weight distribution in spite of the catalyst system using one kind of a transition metal compound, or to give polymers having high molecular weight and be excellent in the polymerization activity at low polymerization temperature.

Abstract: Catalyst systems useful in addition polymerization reactions comprising a Group 4 metal complex and a silylium salt activating cocatalyst are prepared by contacting the metal complex with a silylium salt of a compatible, non-coordinating anion, optionally the silylium salt is prepared by electrochemical oxidation and splitting of the corresponding disilane compound.

Abstract: Disclosed is a titanium catalyst component for ethylene polymerization obtained by contacting [A] a solid magnesium aluminum complex containing magnesium, halogen, aluminum and an alkoxy group and/or alcohol having at least 6 carbon atoms, with [B] a tetravalent titanium compound. The solid magnesium aluminum complex [A] is obtained by contacting (a-1) a magnesium solution formed from a halogen-containing magnesium compound, an alcohol having at least 6 carbon atoms and a hydrocarbon solvent, with (a-2) an organoaluminum compound. Also disclosed is a process for ethylene polymerization comprising polymerizing ethylene or copolymerizing ethylene with an .alpha.-olefin having 3 to 20 carbon atoms in the presence of a catalyst for ethylene polymerization comprising [I] the above-mentioned titanium catalyst component for ethylene polymerization and [II] an organoaluminum compound catalyst component.

Abstract: A composition, which can be used as catalyst for producing an olefin polymer having a multimodal molecular weight distribution, is provided that comprises a transition metal-containing catalyst, a metallocene, and a boron-containing organoaluminoxane, wherein each component of the composition is present in an effective amount so that an olefin polymer having a multimodal molecular weight distribution can be produced using the composition as catalyst, preferably in the presence of a cocatalyst. Also provided is a process for preparing the composition which comprises: (1) contacting a transition metal-containing catalyst with an organoaluminoxane dispersed in a solvent to form a slurry; (2) combining the slurry with a boroxine to prepare a combination of a transition metal-containing catalyst and boron-containing organoaluminoxane; and (3) contacting the combination with a metallocene. Further provided is a process for polymerizing an olefin to prepare an olefin polymer using the composition.

Abstract: The present invention provides hydrophilic crosslinked polymer fine particles made of a copolymer composed of:2-50% by weight of (a) a monoethylenic monomer having a polyoxyalkylene or polyvinylpyrrolidone chain,20-97% by weight of (b) a (meth)acrylamide type monoethylenic monomer,1-30% by weight of (c) a crosslinkable unsaturated monomer having at least one N-methylol or N-alkoxymethyl group and a polymerizable double bond, and0-50% by weight of (d) other monoethylenic monomer.Said polymer fine particles are superior in polymerization stability as well as in dispersion stability during storage, undergoes no adverse effect by dispersion stabilizer owing to no use of said stabilizer, and are suitably used for formation of a hydrophilic film.

Abstract: The present invention provides olefin polymerization catalysts and processes for preparing a polypropylene and a propylene block copolymer using said olefin polymerization catalysts.The olefin polymerization catalyst (1) of the invention is formed from:[I-1] a contact product obtained by contacting:(A) a solid titanium catalyst component,(B) an organometallic compound catalyst component, and(C) a specific organosilicon compound;[II-1] (D) a specific polyether compound; and optionally,[III] an organometallic compound catalyst component.The olefin polymerization catalyst (2) of the invention is formed from:[I-2] a contact product obtained by contacting:(A) a solid titanium catalyst component,(B) an organometallic compound catalyst component, and(D) a specific polyether compound;[11-2] (C) a specific organosilicon 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 a Si--OR or Si--OCOR or Si--NR.sub.2 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, selected type of electron-donor compound.

Abstract: Branched low-pressure polyethylenes are prepared by oligomerization of ethylene on a nickel-containing catalyst and polymerization of the oligomers obtained, if appropriate in the presence of ethylene, on a chromium-containing catalyst.

Abstract: Disclosed is a novel transition metal compound represented by the following formula: ##STR1## wherein M is a transition metal, X is halogen or the like, R.sup.1 is a hydrocarbon group or the like, R.sup.2 is an aryl group substituted with a halogenated hydrocarbon group, and Y is a divalent silicon-containing group or the like.Also disclosed are an olefin polymerization catalyst component comprising the transition metal compound, an olefin polymerization catalyst comprising the olefin polymerization catalyst component, and a process for olefin polymerization using the olefin polymerization catalyst.An olefin polymerization catalyst component having high polymerization activity can be formed from the transition metal compound. By the use of the olefin polymerization catalyst or the process for olefin polymerization, polyolefins having a high melting point and a high molecular weight can be prepared with high polymerization activity.

Abstract: An .alpha.-olefin polymerization catalyst system having so high a catalytic activity and stereoregularity that the catalyst residue and amorphous polymer need not be removed and a process for producing an.alpha.-olefin polymer using the catalyst system, said catalyst system consisting essentially of:(A) a trivalent titanium compound-containing solid catalyst component prepared by reducing a titanium compound, represented by the general formula Ti(OR.sup.1).sub.a X.sub.4-a in which R.sup.1 represents a hydrocarbon group having 1 to 20 carbon atoms; X represents a halogen atom; and a represents a numeral satisfying 0<a.ltoreq.

Abstract: A catalyst compound of the formula (I) is useful in the polymerization of ethylene into homopolymers or copolymers of high density and high melt flow ratio. The catalyst is prepared with a partial activation step before its complete activation with a co-catalyst.Mg.sub.a Ti(OR).sub.b X.sub.c Al.sub.d (R").sub.ej X'.sub.fj H.sub.gj [ED].sub.h B.sub.i Br.sub.

Abstract: A method for producing a stereoregular polyolefin in the presence of a catalyst comprising a transition metal compound and an organometallic compound, which comprises polymerizing at least one olefin in the presence of a catalyst system comprising:(A) a solid catalyst component comprising Mg, Ti, halogen and an electron donative compound,(B) at least one member selected from the group consisting of organometallic compounds of metals of Groups IA, IIA, IIB, IIIB and IVB of the Periodic Table,(C) an electron donative compound, and(D) a boron compound of the formula R.sup.1.sub.n BX.sub.3-n wherein R.sup.1 is a hydrocarbon group and/or a halogenated hydrocarbon group, X is a halogen atom, and 0.ltoreq.n.ltoreq.3.

Abstract: A molded article of a syndiotactic polypropylene having excellent transparency in which a melting point attributed to the polypropylene having the syndiotactic structure measured at a heating rate of 10.degree. C./minute by differential scanning thermal analysis is represented by a substantially single peak, the aforesaid molded article being prepared by heating, melting and then hot-molding a homopolymer of propylene or a copolymer of propylene and a small amount of another olefin, which have a substantially syndiotactic structure, or a mixture of the homopolymer or the copolymer and a small amount of a polypropylene having a substantially isotactic structure, followed by quenching, or, after these steps, additionally subjecting the above molded article to a heat treatment at a temperature of less than its melting point. A method for preparing the above molded article is also disclosed here.

Abstract: The present invention is directed to a supported metallocene catalyst useful in the polymerization of .alpha.-olefins which is obtained by tethering a metallocene catalyst component to the surface of a particulate, functionalized copolymeric support material.

Abstract: A process for the preparation of ultrahigh molecular weight polyethylene having a high bulk density by polymerization of ethylene in the presence of a mixed catalyst, the catalyst comprising an organic aluminum compound and a titanium component prepared by reduction of a Ti(IV) compound and after-treatment of the reduction product thereof with an organic aluminum compound.

Abstract: In accordance with the present invention, there is provided catalyst systems and processes for preparing such catalyst systems comprising reacting a metallocene compound, a solid organoaluminoxy product, and an organometal compound. Further there is provided processes for the polymerization of olefins using the catalyst systems.

Abstract: As improved process for producing an olefin polymer or copolymer by using a novel catalyst composition composed of (A) a titanium catalyst component containing magnesium, titanium, halogen and an ester specified in claim 1, as an electron donor, (B) an organoaluminum compound and (C) a heterocyclic compound or a ketone specified in claim 1, as a third component. The combination parameter of the ester in (A) and the (C) component is new, and the process can give a highly stereospecific olefin polymer or copolymer in high yields.

Abstract: Catalysts comprising (a) derivatives of mono, bi and tricyclopentadienyl coordination complexes with a transition metal and (b) an alumoxane are employed in a process of producing polyolefins of controlled molecular weight.

Abstract: A process for producing an olefin polymer comprising polymerizing an olefin or olefins in the presence of a catalyst system, in which the catalyst system comprises of (A) a hydrocarbon-insoluble solid catalyst component obtained by treating a uniform hydrocarbon solution containing (a) an magnesium compound, e.g., a dialkoxymagnesium, (b) an titanium compound, e.g., a titanium tetraalkoxide, and (c) a polyalkyltitanate represented by formula (I): ##STR1## wherein R.sup.3 's, which may be the same or different, each represent an alkyl group, an aryl group, or a cycloalkyl group; and p represents an integer of from 2 to 20, with a halogenating agent and (B) an organoaluminum compound. The resulting olefin polymer has broad molecular weight distribution, high melt tension, and high melt elasticity and is freed of fish eye by kneading under ordinary conditions.

Abstract: A process is disclosed for the polymerization of olefins, using (i) a catalyst and (ii) an organometallic activator from Groups I, II or III of the Periodic Table at temperatures between 20.degree. and 250.degree. C., and pressure up to 200 bar, in solution, or in suspension in an inert liquid hydrocarbon, at temperatures between 160.degree. and 350.degree. C., under pressures of between 400 and 3000 bar, in a continuous manner in a reactor where the mean residence time of the catalyst is between 1 and 150 seconds. The catalyst comprises at least one titanium compound, at least one halogen-containing organoaluminum compound and at least one inorganic magnesium compound in suspension in at least one .alpha.,.omega.-dihaloalkane. The titanium compound is essentially a titanium (III) compound, the total content of titanium (II) and titanium (IV) being less than or equal to 15% of the total content of titanium.