Abstract: Fractionable, reactor blend polypropylenes, directly obtainable from the polymerization reaction of propylene, having:(a) content of isotactic pentads (mmmm) comprised between 25 and 85%;(b) ratio M.sub.w /M.sub.n <5;containing from 10 to 70% by weight of a fraction soluble in boiling diethyl ether, said fraction having a content of isotactic pentads (mmmm) comprised between 5 and 25%, and from 30 to 90% by weight of a boiling n-heptane-insoluble fraction, soluble in xylene at 135.degree. C., said fraction having a content of isotactic pentads (mmmm) comprised between 50 and 99%, are disclosed. These polymers are suitable as thermoplastic-elastomeric materials. A process for the preparation of these polymers and a process for the preparation of 2-aryl-substituted indenyl metallocene ligands is also disclosed.

Abstract: A method for preventing sheeting problems in a gas phase reactor in such multi-phase polymerization process, which comprises at least one loop reactor followed by a gas phase reactor, where the polymerization is continued in the presence of added monomers, and in which process a fouling preventive agent is used to prevent fouling or sheeting in the reactors. According to the invention 30-70% of the end product is polymerized in the loop reactor, where the whole amount of the fouling preventive agent is added, the amount of the fouling preventive agent being higher than necessary to prevent the fouling in the loop reactor.

Abstract: Components and catalysts for the polymerization of olefins comprising the product obtained by contacting a compound of a transition metal M, containing at least one M-.pi. bond, with an olefinic prepolymer obtained by polymerization of one or more olefins with a coordination catalyst comprising a compound of Ti or V supported on a magnesium halide.

Abstract: A process for homo or copolymerizing propylene, wherein propylene is polymerized in the presence of a catalyst at an elevated temperature in a reaction medium in which a major part of the reaction medium is propylene and the polymerization is carried in at least one CSTR or loop reactor, where the polymerization is carried out at a temperature and a pressure which are above the corresponding critical temperature and the pressure of the reaction medium and where the residence time is at least 15 minutes. The process can also comprise a supercritical loop polymerization before the supercritical stage polymerization or a gas phase polymerization after the supercritical stage polymerization.

Abstract: An ethylene polymer having small values of Mw/Mn and Mz/Mw, a small proportion of long-chain branches, a high melt tension and a high swell ratio, and a process for preparing the ethylene polymer are disclosed. A solid titanium catalyst component obtained by initially bringing a solid titanium composite which is obtained by the contact of a solid magnesium aluminum composite containing magnesium, halogen, aluminum, and an alkoxy group of 6 or more carbon atoms and/or alcohol of 6 or more carbon atoms with a tetravalent titanium compound into contact with an organometallic compound, and then bringing the resulting product into contact with oxygen is further disclosed. An ethylene polymerization catalyst comprising the above catalyst component and an organometallic compound catalyst component is furthermore disclosed. Therefore, the ethylene polymer is excellent in moldability, and a molded article obtained therefrom is excellent in rigidity and impact resistance and free from poor appearance.

Abstract: A high-performance prepolymerized solid catalyst is prepared by polymerizing an olefin onto an olefin polymerization catalyst in a heterogeneous system under irradiation with an elastic wave, wherein the olefin is prepolymerized in an amount of not less than 0.1 g based on 1 mmol of a transition metal contained in the olefin polymerization catalyst. The elastic wave is preferably an ultrasonic wave. In a process for heterogeneous polymerization of an olefin, an olefin is subjected to slurry polymerization or gas phase polymerization in the presence of the prepolymerized solid catalyst. In a process for heterogeneous polymerization of an olefin, an olefin may be polymerized onto the olefin polymerization catalyst in a heterogeneous system under irradiation with an elastic wave to prepare polyolefin. Therefore, the heterogeneous polymerization of an olefin can be stably conducted and polyolefins of uniform property and high quality can be obtained.

Abstract: A liquid phase polymerization process is provided for producing a polyolefin elastomer, e.g., one derived from ethylene, another .alpha.-olefin such as propylene and, optionally, a diene, employing a metallocene catalyst. The process comprises contacting monomer under liquid phase polymerization conditions with a catalyst composition obtained by combining (a) a metallocene procatalyst, preferably one containing a bridging group possessing at least two bulky groups, and (b) a cocatalyst such as aluminoxane, preferably a cation-generating cocatalyst, in partial on total replacement of aluminoxane.

Abstract: A process for olefin polymerization, including polymerizing or copolymerizing an olefin in the presence of an olefin polymerization catalyst composed of: a fine particle carrier; (A) a transition metal compound of a Group IVB metal of the periodic table, containing a ligand having a cyclopentadienyl skeleton; (B) an aluminoxane compound; and optionally (C) an organoaluminum compound, wherein said aluminoxane compound has an alkyl groups to aluminum ratio of 1.3 to 2.1; said transition metal compound (A) and said organoaluminum oxy-compound (B) and said organoaluminum compound being supported on the fine particle carrier; and said solid catalyst having a bulk density of 0.3 g/cm.sup.3 to 0.5 g/cm.sup.3 and a fluidity index of 45 to 70 and an olefin polymerization process using the olefin polymerization catalyst; and an olefin prepolymerized catalyst obtained by prepolymerizing the catalyst, and an olefin polymerization process using the olefin prepolymerized catalyst.

Abstract: The invention relates to continuous gas fluidised bed polymerisation of olefins, especially ethylene, propylene, or mixtures of these with other alpha olefins, wherein the monomer-containing recycle gas employed to fluidise the bed is cooled to condense out at least some liquid hydrocarbon. The condensed liquid, which can be a monomer or an inert liquid, is separated from the recycle gas and is fed directly to the bed to produce cooling by latent heat of evaporation. The liquid feeding to the bed can be through gas-induced atomiser nozzles (FIG. 2), or through liquid-only nozzles. The process provides substantially improved productivity of gas fluidised bed polymerisation of olefins.

Abstract: There is provided a process for preparing a polydiene comprising polymerizing a diene selected from the group consisting of butadiene, isoprene, or a mixture thereof under polymerization conditions in a gas phase reactor optionally in the presence of an inert particulate material and in the presence of a catalyst comprising (i) a rare earth metal component, (ii) a transition metal component selected from the group consisting of nickel compound, cobalt compound or titanium compound, and (iii) cocatalyst.

Abstract: Process for manufacturing ethylene copolymers by polymerizing ethylene and a minor amount of C.sub.3 -C.sub.6 alphaolefins in particle form in slurry reactor in the presence of an ethylene polymerizing catalyst. According to the invention the polymerization is carried out in propane diluent by using a metallocene catalyst activated with an alumoxane compound.

Abstract: A method for polymerizing olefins which comprises using a catalyst which comprises, as the essential components, (A) a metallocene-type transition metal compound and (B) at least one member selected from the group consisting of (1) an ion-exchanging layered compound other than a silicate and (2) an inorganic silicate, which is obtained by salt-treatment and/or acid-treatment and which has a water content of not higher than 1% by weight.

Abstract: Disclosed is a catalyst precursor, useful to make catalysts useful in the polymerization of olefins, comprising the product obtained by adding a preformed magnesium source to a solution comprising a solvent having dissolved therein a transition metal compound and an alkyl halide.

Abstract: The present invention teaches the use of an effervescent nozzle to deliver liquid catalyst to a gas phase polymerization system.

Abstract: A solid titanium catalyst component ?Ia! containing magnesium, halogen, titanium and a compound having at least two ether linkags with a plurality of intermediately existing bonding atoms; a catalyst and a prepolymerized olefin-containing catalyst prepared by using the solid titanium catalyst component ?Ia!; a method for preparing a polyolefin wherein said catalyst or prepolymerized olefin containing catayst is used. A catalyst and a prepolymerized olefin containing catalyst prepared by using a solid titanium catalyst component ?Ib! containing magnesium, halogen, titanium and a specific electron donor (al), and a compound having at least two ether linkags with a plurality of intermediately existing bonding atoms; a method for preparing a polyolefin wherein said catalyst or prepolymerized olefin containing catayst is used.

Abstract: Catalyst for the polymerization of olefins, process for its preparation, and its use.The present invention relates to a supported catalyst for the polymerization of olefins, which can be prepared by reacting the reaction product formed from an aluminoxane and at least one metallocene with a microporous, polymeric support.

Abstract: A high-performance prepolymerized solid catalyst is prepared by polymerizing an olefin onto an olefin polymerization catalyst in a heterogeneous system under irradiation with an elastic wave, wherein the olefin is prepolymerized in an amount of not less than 0.1 g based on 1 mmol of a transition metal contained in the olefin polymerization catalyst. The elastic wave is preferably an ultrasonic wave.

Abstract: Metallocene complexes of a metal M selected from titanium, zirconium and hafnium, comprising at least one anionic group A containing an .eta..sup.5 -cyclopentadienyl ring co-ordinated with the metal M, wherein the anionic group is substituted in at least one position of the cyclopentadienyl ring with a radical having the formula:Ph*--(CR.sup.6 R.sup.7).sub.nwherein: R.sup.6 and R.sup.7 are independently hydrogen, halogen or a C.sub.1 -C.sub.4 alkyl group, preferably hydrogen, "n" is 0 or 1, preferably 1, Ph* is a C.sub.6 -C.sub.14 group comprising an aromatic ring linked to --CR.sup.6 R.sup.7 -- or to A and substituted with at least one and up to a maximum of three electron-attractor groups, on the condition that, when A is an .eta..sup.5 -indenyl group and "n" is 0, at least one Ph group is linked to A in position 1 or 3 of indenyl.These complexes can be used in (co)polymerization processes of .alpha.

Abstract: Process for the in situ polymerization of ethylene with C.sub.3 -C.sub.10 alpha-olefins in suspension of liquid monomer in the presence of a catalyst containing Vanadium obtained by the precipitation, in an atmosphere of ethylene or alpha-olefins, of:a) a compound of Vanadium in the oxidation state of 3 to 5, withb) a basically hydrocarbon solution of a compound selected from those having general formula R.sub.n AlX.sub.m wherein R is a C.sub.1 -C.sub.20 alkyl radical, X is a halogen, m+n=3, n is an integer from 0 to 2.

Abstract: There are provided a propylene-based polymer characterized in that (1) the xylene-extraction insoluble portion (XI) is 99.0 wt % or greater, (2) the isotactic pentad ratio (IP) is 98.0% or greater as measured by .sup.13 C nuclear magnetic resonance spectroscopy, (3) the isotactic average chain length (N) is 500 or greater, and (4) the total amount of each of the fractions obtained by column separation of the xylene insolubles whose average chain length (N.sub.f) is 800 or greater accounts for 10 wt % or more of the entirety, and a method for its production, as well as a propylene-based polymer composition prepared by combining with this propylene-based polymer at least a nucleating agent in the range of 0.05-15 wt %. In addition, there are provided a polymerization catalyst component allowing the production of such a propylene-based polymer, and a method for its production.

Abstract: Catalysts consisting ofA) an alcoholate of the rare earths, a carboxylate of the rare earths, a complex compound of the rare earths with diketones and/or an addition compound of the halides of the rare earths with an oxygen or nitrogen donor compound,B) an aluminium trialkyl, a dialkyl aluminium hydride and/or an alumoxane,C) another Lewis acid andD) an inert, particulate inorganic solid with a specific surface of greater than 10 m.sup.2 /g (BET) and a pore volume of 0.3 to 15 ml/gare eminently suitable for the polymerization of conjugated dienes, more particularly butadiene, in the gas phase.

Abstract: In gas phase polymerizations and copolymerizations of ethylene, reagents or cofeeds control the molecular weight, expressed as MI (wherein MI is measured according to ASTM D-1238 Condition E), of the resin product. Use of isopentane and electron donating compounds decrease MI; whereas, electron withdrawing compounds increase MI.

Abstract: The present invention provides an ethylene copolymer comprising constituent units (a) derived from ethylene and constituent units (b) derived from an .alpha.-olefin having 3 to 20 carbon atoms, the ethylene copolymer being characterized in that(A) the ethylene copolymer has a density (d) of 0.86 to 0.95 g/cm.sup.3 ;(B) the ethylene copolymer has a MFR of 0.001 to 50 g/10 min as measured at a temperature of 190.degree. C. and a load of 2.16 kg;(C) the melt tension (MT) and MFR of the ethylene copolymer satisfy the relationlog MT>-0.66 log MFR+0.6; and(D) the temperature (T) at which the exothermic curve of the ethylene copolymer measured by a differential scanning calorimeter (DSC) shows the highest peak and the density (d) satisfy the relationT<400 d-250.

Abstract: The present invention relates to a prepolymer for the polymerization of olefins, the said prepolymer achieving a combination of a number of solid catalytic components for the polymerization of olefins. The combination of catalytic components makes it possible to combine two properties within the same polymer, one of the properties being contributed by one of the catalytic components and the other property being contributed by the other catalytic component.

Abstract: The present invention provides an ethylene copolymer comprising constituent units (a) derived from ethylene and constituent units (b) derived from an .alpha.-olefin having 3 to 20 carbon atoms, the ethylene copolymer being characterized in that(A) the ethylene copolymer has a density (d) of 0.86 to 0.95 g/cm.sup.3 ;(B) the ethylene copolymer has a MFR of 0.001 to 50 g/10 min as measured at a temperature of 190.degree. C. and a load of 2.16 kg;(C) the melt tension (MT) and MFR of the ethylene copolymer satisfy the relationlog MT>-0.66log MFR+0.6; and(D) the temperature (T) at which the exothermic curve of the ethylene copolymer measured by a differential scanning calorimeter (DSC) shows the highest peak and the density (d) satisfy the relationT<400d-250.

Abstract: In accordance with the present invention, there are provided an olefin polymerization catalyst comprising an organoaluminum oxy-compound (A), a transition metal compound (B) and a hydrogenated organoaluminum compound (C); a solid olefin polymerization catalyst comprising the above-mentioned components (A), (B), (C) and a carrier (D); a prepolymerized catalyst formed by prepolymerization of olefin on a catalyst component comprising the above-mentioned components (A), (B), (C) and (D); an olefin polymerization catalyst comprising the above-mentioned solid olefin polymerization catalyst or the above-mentioned prepolymerized catalyst and an organoaluminum compound; and a method for the polymerization of olefin which comprises polymerizing olefin in the presence of the above-mentioned catalysts.

Abstract: A process for preparing polynuclear metallocenes by reacting a metallocene in which one of the cyclopentadienyl-containing radicals has a substituent having olefinic or acetylenic unsaturation with a second metallocene having a metal which comes from groups IVb to VIb of the periodic table and a metal-hydride bond. The use of the resulting metallocenes in the polymerization of olefins is disclosed, including techniques for using such metallocenes to produce solid prepolymerized metallocene-containing catalyst systems suitable for use in the polymerization of olefins.

Abstract: A catalyst for olefin polymerization obtainable by contacting:(a) a transition metal compound containing a transition metal of the Group 4 of the Periodic Table,(b) an organometallic compound, and(c) a solid catalyst component comprising a carrier and an ionized ionic compound capable of forming a stable anion on reaction with a transition metal compound, wherein the ionized ionic compound comprises a cationic component and an anionic component and the cationic component is fixed on the surface of the carrier. The catalyst system of the invention enables production of olefin polymers with excellent physical properties at good productivity without causing contamination of a polymerization vessel.

Abstract: Process for the preparation in liquid phase of copolymers of ethylene with propylene and optionally another diene, in the presence of a catalyst selected from (a) Titanium salt supported on magnesium salt and (b) compound of Vanadium soluble in hydrocarbon solvents either supported on an inert material or prepolymerized, and a co-catalyst essentially consisting of an organic compound of Aluminium, and a possible chlorinated activator, characterized in that:1) when the polymerization is almost complete, a solid material insoluble in the reaction environment and having an average diameter of between 0.001 and 200 microns is added to the reaction mixture;2) the suspension of polymer and solid material are kept in contact for a sufficient time to obtain perfectly free-flowing polymeric particles;3) the perfectly free-flowing polymeric particles of step (2) are recovered.

Abstract: Process for preparing a poly-1-olefinBy means of a highly active spherical Ziegler catalyst based on a dialkylmagnesium, spherical polymers can be obtained in the polymerization of alpha-olefins. A further advantage of the catalyst of the invention lies in the high catalyst activity, so that only very small amounts of the catalyst are required for the polymerization. The residual titanium and/or zirconium content in the polymers prepared according to the invention is less than 10 ppm. Owing to its good responsiveness to hydrogen, the catalyst is particularly suited to two-stage processes for preparing polymers having a broad bimodal molecular weight distribution. The replacement of sulfur-containing electron donors such as diethyl sulfite by alcohols such as ethanol leads to less odor problems and broadened opportunities for use of the polymer.

Abstract: A colorable resin particle having an outer shell of a non-sticky polymer and an inner core of a sticky polymer produced in a gas phase fluidized bed reactor at or above the sticking temperature of the sticky polymer using a non-sticky prepolymerized catalyst and processes for producing the colorable resin and the non-sticky prepolymerized catalyst.

Abstract: A solid titanium catalyst component comprising (a) magnesium, (b) titanium, (c) a halogen, (d) a polyether, (e) a hydrocarbon and (f) an electron donor other than the polyether (d) as essential components is provided. Also a process for preparing a solid titanium catalyst component for olefin polymerization, comprising the steps of contacting a halogenated magnesium compound with a compound selected from the group consisting of an alcohol, an ether and an ester in a hydrocarbon solvent to obtain a magnesium compound solution, contacting the magnesium compound solution with a polyether and contacting the resultant solution with a liquid titanium compound is provided. Further, a catalyst for olefin polymerization comprising the above-mentioned solid titanium catalyst component, an organoaluminum compound catalyst component and an electron donor, and a process for polymerizing an olefin using the catalyst for olefin polymerization are also disclosed.

Abstract: Process with two or more steps for the preparation in suspension of mixtures of ethylene-propylene (EPM) elastomer homopolymers or ethylene-propylene-diene (EPDM) elastomer terpolymers in the presence of a catalytic system essentially consisting of a compound of Vanadium and a cocatalyst essentially consisting of an Aluminum alkyl and in the presence of an activator, the above process being characterized in that:a) in the first step a first polymerization of the monomers is carried out in the presence of the Vanadium based catalyst;b) in the second or subsequent steps further polymerizable monomers and activator are added to the suspension of the polymer obtained in step (a).

Abstract: Solid precursor of a catalytic system for the polymerization of olefins, containing at least one neutral halogenated metallocene derived from a transition metal, the latter being linked to at least one halogen atom, and at least one ionizing agent.Process for the preparation of this solid precursor, according to which a compound based on the neutral halogenated metallocene is mixed with a compound based on the ionizing agent in a heterogeneous medium. Catalytic system comprising an organometallic compound derived from a metal chosen from groups IA, IIA, IIB, IIIA and IVA of the Periodic Table, and a solid precursor described above. Process for the polymerization of olefins, in which this catalytic system is used.

Abstract: An olefin homogeneous polymerization catalyst demonstrating increased activity is formed from a cyclopentadienyl metallocene component, a salt of a compatible cation and a non-coordinating anion, and a C.sub.3 -C.sub.6 trialkylaluminum, preferably triisobutylaluminum. A homogeneous polymerization process comprises controlling polymerization activity with such catalyst by controlling the aluminum/metal (Al/M) molar ratio to a minimal level within the effective range of Al/M ratios.

Abstract: A novel class of olefin polymerization catalyst system based on specific organo-transition metal compounds and which are effective for controlling in particular the width and mode of the molecular weight distribution of the resulting polyolefins, and processes of olefin polymerization using the novel catalyst systems are disclosed.

Abstract: A catalyst for the polymerization of olefines comprises a solid catalytic component obtained by pre-polymerizing propylene in the presence of (A) a solid component containing magnesium, titanium, halogen and an electron-donating compound, (B) an organoaluminum compound, and (C) an alkylalkoxysilane represented by the formula, R.sup.1 Si(OR.sup.2)(OCH.sub.3).sub.2, wherein R.sup.1 represents a branched or cyclic alkyl group having 3 to 6 carbon atoms, and R.sup.2 represents a branched alkyl, alkenyl or alkinyl group having 3 to 6 carbon atoms; (B) an organoaluminum compound; and (D) an alkyltrialkoxysilane represented by the formula, R.sup.3 Si(OR.sup.4).sub.2 (OCH.sub.3), wherein R.sup.3 represents a linear alkyl group having 3 to 6 carbon atoms, and R.sup.4 represents a branched alkyl, alkenyl or alkinyl group having 3 to 5 carbon atoms.

Abstract: Fractionable, reactor blend polypropylenes, directly obtainable from the polymerization reaction of propylene, having:(a) content of isotactic pentads (mmmm) comprised between 25 and 85%;(b) ratio M.sub.w,/M.sub.n <5;containing from 10 to 70% by weight of a fraction soluble in boiling diethyl ether, said fraction having a content of isotactic pentads (mmmm) comprised between 5 and 25%, and from 30 to 90% by weight of a boiling n-heptane-insoluble fraction, soluble in xylene at 135.degree. C., said fraction having a content of isotactic pentads (mmmm) comprised between 50 and 99%, are disclosed. These polymers are suitable as thermoplastic-elastomeric materials. A process for the preparation of these polymers and a process for the preparation of 2-aryl-substituted indenyl metallocene ligands is also disclosed.

Abstract: A process for the production of elastomeric polypropylene is disclosed. The process entails contacting the propylene monomer neat or in an unreactive hydrocarbon solvent, with a catalyst in a recirculated, stirred reactor at a temperature of about 60.degree. to 80.degree. C. thereby producing elastomeric polypropylene. The reactor contents are in the slurry/solution phase and are essentially free of catalyst poisons. The reactor is capable of recirculating contents that are very viscous such that the reactor contents are well mixed while a portion of the contents of the reactor containing propylene, any solvent, and elastomeric polypropylene are continually removed by the use of a high viscosity pump to recover the elastomeric polypropylene.

Abstract: The present invention relates to a metallocene compound of the formula I ##STR1## which can advantageously be used as catalyst component for olefin polymerization.

Abstract: The present invention concerns prepolymerized catalyst composition for polymerization of .alpha.-olefins, a process for the preparation thereof and a process for polymerization of .alpha.-olefins. According to the polymerization process a procatalyst composition containing a transition metal is prepolymerized with a monomer in order to produce a prepolymerized Ziegler-Natta type catalyst composition and said catalyst composition is contacted with an alpha-olefin monomer, in particular with ethylene or propylene, for preparing a polymer. According to the invention the procatalyst composition is preferably prepolymerized in a medium which is inert to the catalyst components, the viscosity of the medium being so high that the catalyst does not substantially settle in this medium. Because the catalyst composition according to the invention does not have to be dried before being fed into the medium, its activity is high before and during polymerization.

Abstract: The organic carrier supported metallocene catalyst of the present invention is prepared by preparing a ligand complex of a silicone compound having at least one halogen, an alkyl group and a cycloalkane dienyl group, activating styrene polymer or styrene/divinylbenzene copolymer with a strong base including a metal atom such as Li, Na, K or Mg, reacting the activated polymer or copolymer with the ligand complex of a silicone compound so that the ligand may be supported on the activated polymer or copolymer, and reacting the organic carrier supported ligand with a compound of a transition metal of Group IVb of the Periodic Table or Lanthanides of Atomic Number 58-71. The styrene polymer or styrene/divinylbenzene copolymer may be alkylated by Friedel-Crafts alkylation before they are activated with a strong base.

Abstract: Gas-phase process for the preparation of polymers and copolymers of olefins CH.sub.2 .dbd.CHR, carried out in at least 2 fluidized or mechanically agitated bed gas-phase reactors operating under different reaction conditions so as to obtain different polymers in the different reactors; the process is characterized in that the polymer is at least partially recycled among the different reactors by using ratios of the flow rate of circulation among the different reactors to the discharge flow rate comprised between 2 and 6.

Abstract: A solid titanium catalyst component ?Ia! containing magnesium, halogen, titanium and a compound having at least two ether linkags with a plurality of intermediately existing bonding atoms; a catalyst and a prepolymerized olefin-containing catalyst prepared by using the solid titanium catalyst component ?Ia!; a method for preparing a polyolefin wherein said catalyst or prepolymerized olefin containing catayst is used. A catalyst and a prepolymerized olefin containing catalyst prepared by using a solid titanium catalyst component ?Ib! containing magnesium, halogen, titanium and a specific electron donor (a1), and a compound having at least two ether linkags with a plurality of intermediately existing bonding atoms; a method for preparing a polyolefin wherein said catalyst or prepolymerized olefin containing catayst is used.

Abstract: Catalyst compositions comprising metallocene complexes having polymerisable may be used for the preparation of polyolefins.The catalyst compositions may be in the form of polymers comprising the metallocene complex and may be suitably supported on inorganic supports. Polymers having a broad range of density and melt indices as well as low hexane extractables and excellent powder morphology and flowability may be obtained by use of the catalyst compositions. Preferred metallocene complexes are zirconium complexes in which the polymerisable group is vinyl.

Abstract: A process for polymerizing propylene utilizes a metallocene catalyst component of the formula (I) ##STR1## wherein M is a transition metal, R.sup.1 is a C.sub.2-6 hydrocarbon, R.sup.2 is a C.sub.6-16 aryl group, X.sup.1 and X.sup.2 are each a halogen atom and Y is a divalent hydrocarbon or a divalent silicon-containing group. Propylene polymers produced thereby have such properties that the triad tacticity of propylene units is high, the proportion of inversely inserted units based on the 2,1-insertion of propylene monomer is in a specific range and the intrinsic viscosity (.eta.), as measured in decahydronaphthalene at 135.degree. C., is in a specific range.

Abstract: This invention relates to a process for polymerizing olefins using a catalyst composed of a transition metal catalyst component, an aluminoxane component and an organoaluminum component. In the process of this invention, the catalyst exhibits excellent polymerization activity with the use of a small amount of the aluminoxane xane. The polymerization process gives olefin polymers having a narrow molecular weight distribution and by the copolymerization of two or more olefins, gives olefin copolymers having a narrow molecular weight distribution and a narrow composition distribution.

Abstract: The present invention relates to components of catalysts for the polymerization of olefins comprising a metallocene compound and a magnesium halide which have particular values of porosity and surface area. In particular the components of the invention have surface area (BET) greater than about 50 m.sup.2 /g, porosity (BET) greater than about 0.15 cm.sup.3 /g and porosity (Hg) greater than 0.3 cm.sup.3 /g, with the proviso that when the surface area is less than about 150 m.sup.2 /g, the porosity (Hg) is less than about 1.5 cm.sup.3 /g. The components of the invention are particularly suitable for the preparation of catalysts for the gas-phase polymerization of .alpha.-olefins.

Abstract: This invention is a solution process for the preparation of ethylene-.alpha.-olefin/diolefin copolymers comprising contacting ethylene, one or more .alpha.-olefin monomer, and optionally one or more diene monomer, with a catalyst system containing a catalyst activator and a Group 4 metallocene compound, comprising a) conducting the polymerization reaction at a temperature of about 60.degree. to 150.degree. C.; b) selecting as the Group 4 metallocene compound one or more members of the group consisting of cyclic monocyclopentadienyl Group 4 metal and covalently bridged (bis)indenyl hafnium metallocene compounds; and c) maintaining the .alpha.-olefin concentration at a molar ratio to that of ethylene of between about 0.3 to 7.0 and a diolefin to ethylene molar ratio of between about 0.01 and 0.4. In a preferred embodiment the process comprises: 1) mixing with a reaction solvent the one or more .alpha.

Abstract: The present invention relates to a polynuclear metallocene compound of the formula I ##STR1## a process for their preparation and their use as a catalyst for olefin polymerization.