Abstract: A method of making a solid, substantially dry olefin polymerization procatalyst precursor is disclosed whereby a solid precursor containing magnesium and titanium is formed in a slurry or solution, the solid then is separated from the solution and then dried at a temperature above 50.degree. C. for over an hour. Solid, substantially dry olefin polymerization procatalyst precursors made by the method also are disclosed, whereby the precursors are easier to handle, have better flowability, reduced clumpness and provide catalysts that can be used to produce polymers having improved extrudability, less filter clogging, less "talc"-like polymer particles of <10 micron in size and reduced polymer product segregation in storage.

Abstract: A solid, hydrocarbon-insoluble, olefin-polymerization catalyst component having substantially uniform particles useful in polymerizing olefins is formed by:reacting a magnesium-containing compound with carbon dioxide or sulfur dioxide;forming a two-phase mixture of the resulting magnesium-containing compound with a suitable liquid hydrocarbon-miscible phase and a suitable polar solvent phase;forming particles by adding the two-phase mixture after vigorous agitation to a liquid hydrocarbon; andcontacting the formed particles at least once with a transition metal halide in the presence of an electron donor.

Abstract: The object of the present invention is to provide a polyolefin having a good particle property in a high yield without use of an expensive alumoxane. The present invention comprises a catalyst for olefin polymerization comprising the following ingredients (A), (B) and (C), and a process for preparing an olefin polymer with use of the catalyst:Component (A): a transition metal compound having at least one conjugated five-membered ring ligand, the transition metal being in the Groups IV-VI of the Periodic Table,Component (B): an organoaluminum compound, andComponent (C): a finely divided particle composition comprising 0.1-99.9% by weight of boric acid.

Abstract: An ethylene-alpha-olefin copolymerization catalyst is prepared by impregnating a porous support, such as silica, with a contact mixture of an organomagnesium compound such as dialkyl magnesium and a silane compound which is free of hydroxyl groups, such as tetraethyl orthosilicate. A transition metal component such as titanium tetrachloride is then incorporated into the support in a specific ratio to the magnesium and silane components. Activation of this catalyst precursor with a trialkylaluminum compound results in a catalyst system which is effective for the production of ethylene copolymers.

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: A catalyst for polymerizing an olefin, which comprises (A) a metallocene transition metal compound, (B) (1) an ion-exchanging layered compound other than a silicate or (2) an inorganic silicate prepared by treating a starting ion-exchanging layer compound other than a silicate or a starting silicate with a salt, an acid, or a combination thereof, said component (B) having a water content not higher than 1% by weight which is obtained by heat-dehydrating component (B) under an inert gas atmosphere or under reduced pressure, and (C) an organoaluminum compound.

Abstract: A supported polymerization catalyst component and a catalyst system useful in the production of polyolefin resins that have a narrow particle size distribution and enhanced crystallization rates is provided. The supported polymerization component comprises talc, an organomagnesium compound or complex, wherein the weight ratio of talc to magnesium in the organomagnesium compound or complex is from about 1000:1 to about 5:1, at least one transition metal containing compound and/or a metallocene effective in alpha-olefin polymerization reactions, and, optionally, an alcohol or a silane. The catalyst system of the instant invention includes the aforementioned alpha-olefin polymerization catalyst component and at least one aluminum-containing cocatalyst compound. A process for polymerizing or copolymerizing alpha-olefins, conducted under olefin polymerization conditions utilizing the inventive catalyst system of this invention is also described.

Abstract: A supported catalyst for the (co)polymerization of alpha-olefins is obtained by putting the following products in contact with each other:(A) a metallocene derivative of a metal selected from the group consisting of transition metals and lanthanides, which is in itself capable of promoting the polymerization of alpha-olefins in the presence of or also without suitable activators;(B) an active support containing magnesium, halogen, titanium and smaller quantities of tin;(C) an organometal derivative of aluminium of which at least 50% of the aluminium atoms are bound to at least one alkyl carbon atom.Components (A) and (B) are preferably interacted first to obtain a supported metallocene derivative, which is then put in contact with (C) to obtain the desired catalyst. Alternatively, (B) and (C) are interacted and subsequently put in contact with (A).

Abstract: The active carrier particles of even size of the polymerization catalyst are prepared so that a melt of a complex composition is provided having the formula (I)MgCl.sub.2 nROH mED (I)in which ROH depicts an aliphatic alcohol, R is a C.sub.1 -C.sub.6 alkyl, ED depicts an electron donor, n is 1 to 6 and m is 0 to 1; the melt provided is fed to a nozzle (4); the melt is sprayed from the nozzle (4) to the spraying area (5), in which it is divided into fine melt droplets and possibly partly solidifies; the possibly partly solidified melt particles are transferred to a cooled crystallization area (6), where they crystallize to solid carrier particles; and the solid carrier particles are recovered. The melt mentioned is sprayed through a nozzle (4), which is rotated or which has attached to it a member that rotates and throws melt outwards from the rotating center to the spraying area (5).

Abstract: A catalyst which exhibits superior control of product particle size in the insertion polymerization of alpha-olefins is described as transition metal compounds which associate with non-coordinating alumoxane anions which are dispersed throughout the interior of a silica support in the form of particles which are less than or equal to about 50 .ANG. (5 nanometers) in diameter. This catalyst is capable of gas phase (e.g. heterogeneous) polymerization of propylene into product granules with a high degree of control over granule particle size distribution and bulk density.

Abstract: A transition metal containing catalyst having a silica-support is provided for the production of polyolefins from .alpha.-olefins that can be converted to polymer films, preferably thin films of polyolefin, which have lower defects resulting from a decreased presence of silica-containing residues from the catalyst. The catalyst has a porous silica support component and a catalytic component which may include, but is not limited to, such materials as chromium, magnesium-titanium (Ziegler-Natta type) or metallocene compounds (Metallocene catalyst type). The porous silica component of the catalyst has an average pore volume of from about 2.5 to about 3.5 ml/g and a surface area of 200 to 400 m.sup.2 /g and preferably 250 to 350 m.sup.2 /g. The average pore diameter ranges from about 285 to about 700 Angstroms and preferably 500-700 Angstroms for porous silica components having surface areas of 200 m.sup.2 /g and preferably 285-400 Angstroms for porous silica components having surface areas of 350 m.sup.2 /g.

Abstract: A process for producing a catalyst carrier for an olefin polymerization comprising:(i) passing a mixture to be emulsified comprised of (A) a halogenated magnesium adduct and (B) a dispersion medium through an emulsifying apparatus comprised of (1) a conduit for passage of the mixture to be emulsified, (2) a vibrator element disposed in the conduit and vibrating in the axial direction of the conduit, and (3) a vibration device for giving the vibration movement to the vibrator element; and(ii) quenching the resultant mixture.

Abstract: A dispersible ionic catalyst activator, comprising an insoluble substrate material having a correlated settling rate less than 0.03 cm/sec, and from 0.001 to 10 mmol/g of an ionic catalyst activator deposited thereon which is particularly adapted for use in a continuous, solution polymerization process.

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: Catalysts comprisingA) a rare earth alkoxide, a rare earth carboxylate and/or a rare earth coordination compound with diketones,B) an alumoxane andC) an inert, particulate, inorganic solid with a specific surface area of greater than 10 m.sup.2 /g and a pore volume of 0.3 to 15 ml/gare excellently suited to the polymerisation of conjugated dienes, in particular butadiene, in the gas phase.

Abstract: The present invention provides a process for preparing a highly active metallocene catalyst by which polyolefin having improved properties can be prepared with a small amount of cocatalyst. A process for preparing a metallocene catalyst of the invention comprises the steps of: modifying the surface of a zeolite or molecular sieve inorganic carrier possessing crystalline pores of 7 to 100 .ANG. size by the addition of an organic solvent and organic aluminum compound under an environment of inert gas and reacting at a constant temperature, and drying; and, impregnating a metallocene compound into the inorganic carrier by the addition of an organic solvent and said metallocene compound, whose diameter is smaller than the diameters of said pores of the inorganic carrier, to the inorganic carrier and reacting at a constant temperature, and drying. In accordance with the present invention, a highly active metallocene catalyst can be prepared in an economical and efficient manner.

Abstract: Olefins or mixtures of olefins, particularly propene or mixtures of propene advantageously with ethene, can be polymerized using a Ziegler-Natta catalyst system containing, besides a transition-metal-based procatalyst and cocatalyst which is an organometallic compound, a compound particularly suited for controlling the stereospecificity of the produced polymer. Such a compound called an external donor may also have other effects. By using an acetal derivative of an aldehyde that has two ether groups for this purpose, advantageously selected from the group of dialkoxyphenylalkanes, e.g., dimethoxyphenylpropane, a good stereospecificity of the product is attained combined with the high hydrogen sensitivity of the catalyst system, whereby the use of hydrogen as the chain transfer agent offers an easy control method of the molecular weight of the product by means of adjusting the amount of hydrogen available in the polymerization reaction.

Abstract: Multi-component catalyst systems for polymerization and copolymerization of olefins consist of at least one transition metal complex containing a multidentate ligand and a three-component cocatalyst. The transition metal complexes with bidentate ligands L have empirical formulasLMX.sub.2, LMXY or L.sub.2 Mwhere M is Ti, V, Zr or Hf atom; X is an alkoxy group, an aryloxy group, or a halogen atom; Y is a mono- or double-bonded ligand different from X. Complexes with tridentate ligands L' have empirical formulas L'MX where M is Ti, V, Zr or Hf; X is an alkoxy group, an aryloxy group, or a halogen atom. Examples of L and L' are alkyldioxy, alkyldiamino, alkyldicarboxy, biaryldioxy, or alkylaminodioxy ligands; particular examples of X are the isopropoxy group or Cl; a particular example of Y is an oxygen atom. The preferred substitution types in the multidentate ligands L and L' are such which afford their unimpeded coordination to the metal atom M in tri-, tetra- or pentacoordinated complexes.

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: A process is provided to modify an olefin production catalyst system which comprises contacting an olefin production catalyst system with ethylene prior to use. A process also is provided to trimerize and/or oligomerize olefins with the novel, modified olefin catalyst production system. The modified olefin production catalyst system produces less solids, such as, for example, polymer.

Abstract: Metal complexes corresponding to the formula: ##STR1## wherein: L independently each occurrence is a delocalized, .pi.-bonded group that is bound to M, containing up to 50 nonhydrogen atoms;M is a metal of Group 3, 4 or the Lanthanide series of the Periodic Table of the Elements;Z is a covalently bound, divalent substituent of up to 50 non-hydrogen atoms having the formula, --(ER.sub.2).sub.m --, wherein E independently each occurrence is carbon, silicon or germanium, R independently each occurrence is selected from the group consisting of C.sub.1-20 hydrocarbyl, and C.sub.1-20 hydrocarbyloxy, with the proviso that in at least one occurrence R is C.sub.

Abstract: Catalyst compositions are provided that comprise (a) discrete silica particles; (b) chromium; and (c) a support comprising silica. These composition are useful in polymerizing ethylene or copolymerizing ethylene with a comonomer and provide better control over the molecular weight and the molecular weight distribution of a resulting polymer.

Abstract: A supported metallocene complex of a metal M selected from Ti, Zr or Hf, is prepared by a process comprising, in a first step, the reaction of an inorganic carrier containing hydroxyl groups with a compound (II) containing a cyclopentadienyl group and at least one alkoxysilane group reactive with said hydroxyl groups so as to chemically bind said cyclopentadienyl group to said carrier; and in a second step the reaction with a complex of said metal M capable of reacting with said supported cyclopentadienyl group without carrying out any intermediate metallation of the latter. This process is simple and convenient, and enables high concentrations of metal stably bound to the carrier, to be reached. The complex thus obtained can be used as solid component of a catalyst active in the polymerization of .alpha.-olefins, in the presence of a suitable co-catalyst, preferably consisting of an organo-oxygenated derivative of aluminum.

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: Process for the manufacture of a support containing silica and at least one constituent chosen from alumina and aluminium phosphate, according to which an alcohol, water, a silicon alkoxide and an acid are mixed under conditions such that gelling or precipitation of silica is prevented, an acidic solution of an aluminium compound and/or a solution of a source of phosphate ions are added thereto, a gelling agent is added thereto, a gel is recovered which is washed with water and then by means of an organic liquid, the gel is then dried by atomization until a powder is obtained, and the powder is calcined. Polymerization of olefins in the presence of a catalyst containing chromium on a support as described above.

Abstract: Analyst for polymerization of olefin is provided which comprises a clay mineral (a) having been modified with a compound (b) capable of introducing a cation into layer interspaces in the clay mineral; a metallocene compound (c); and an organoaluminum compound (d). This catalyst is inexpensive and yet has excellent activity for polymerization of olefin. The process for polymerization or copolymerization of olefins is also provided.

Abstract: (Co)polymerisation process according to which a mixture of a halogenated neutral metallocene as defined above and of an organoaluminium compound is prepared, the olefin is brought into contact with this mixture and an ionising agent is added thereto.

Abstract: Novel chromium-containing compounds, such as, for example, chromium pyrrolides, are prepared by forming a mixture of a chromium salt, a metal amide, and an electron pair donor solvent, such as, for example, an ether. These novel chromium-containing, or chromium pyrrolide, compounds can be used either unsupported or supported on an inorganic oxide support, with a metal alkyl and an unsaturated hydrocarbon, to trimerize, oligomerize, and/or polymerize 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: In a gas phase olefin polymerization, an olefin is continuously fed to a fluid bed reactor in which a metallocene catalyst is present. At least one compound selected from water, alcohols and ketones is added in a specified amount simultaneously with the feeding of the olefin. Thus, an olefin polymer having a satisfactory drop second count index as defined by the below indicated formula is produced: ##EQU1## wherein t.sub.0 and t respectively represent a flow time measured in the flow test according to ASTM D-1775 of the olefin polymer obtained when none of the water, alcohols and ketones is incorporated in the reactor, and when at least one compound of water, alcohols and ketones is incorporated in the reactor. The flowability of the polymer formed in the reactor is excellent, so that blocking, bridging and the like do not occur during the gas phase polymerization. Thus, it is feasible to stably produce a (co)polymer having excellent particle properties in high yield for a prolonged period of time.

Abstract: A novel olefin polymerization catalyst is obtained by contacting the following components (1) to (5) with one another: (1) a compound represented by the general formula Me.sup.1 R.sup.1.sub.p (OR.sup.2).sub.q X.sup.1.sub.4-p-q, (2) a compound represented by the general formula Me.sup.2 R.sup.3.sub.m (OR.sup.4).sub.n X.sup.2.sub.z-m-n, (3) an organocyclic compound having conjugated double bonds; (4) a modified organoaluminum compound having Al--O--Al bond(s); and (5) a silicon oxide and/or an aluminum oxide both having characteristic average particle diameter, specific surface area, volume of pores ranging in pore radius from 18 to 1,000 Angstroms, apparent specific gravity not lower than 0.32, and proportion of 50 .mu.m or smaller particles.

Abstract: Catalyst systems of the Ziegler-Natta type comprising as active constituentsa) a titanium-containing solid component prepared using a titanium compound, a compound of magnesium, a halogenating agent and an electron donor component,b) an aluminum compound andc) as further electron donor component, an organosilicon compound of the formula (I)R.sup.1 R.sup.2 si(OR.sup.3).sub.2 (I)in whichR.sup.1 is a C.sub.1 -C.sub.10 -alkyl radical or a C.sub.3 -C.sub.8 -cycloalkyl radical, R.sup.2 is a 2,4,4,6,6-pentamethylheptyl radical andR.sup.3 is a C.sub.1 -C.sub.8 -alkyl radical,are particularly suitable for the preparation of polymers of C.sub.2 -C.sub.10 -alk-1-enes.

Abstract: Catalyst systems of the Ziegler-Natta type contain, as active componentsa) a titanium-containing solid component in whose preparation a titanium compound, a compound of magnesium, a halogenating agent and an electron donor component are used,b) an aluminum compound andc) as a further electron donor component, an organosilicon compound of the formula (I)R.sup.1 R.sup.2 Si(OR.sup.3).sub.2 (I)where R.sup.1 is C.sup.1 -C.sub.10 -alkyl or C.sub.3 -C.sub.8 -cycloalkyl, excluding sec-butyl, R.sup.2 is sec-butyl and R.sup.3 is C.sub.1 -C.sub.8 -alkyl. The catalyst systems are particularly suitable for the preparation of polymers of C.sub.2 -C.sub.10 -alk-1-enes.

Abstract: Novel Group 4 metal complexes containing one and only one cyclic delocalized, anionic, .pi.-bonded group wherein the metal is in the +4 formal oxidation state and having a bridged ligand structure, also referred to as constrained geometry complexes and a conjugated diene divalent anionic ligand group; catalytic derivatives of such complexes including novel zwiterionic complexes; and the use thereof as catalysts for polymerizing olefins, diolefins and/or acetylenically unsaturated monomers.

Abstract: A supported catalyst composition comprising a complex of a Group 4 metal cyclopentadienyl derivative reacted with silica treated with an aluminoxane demonstrates improved reactivity, especially for incorporating long chain alpha-olefins and also shows improved resistance to catalyst poisoning. The supported catalyst composition is adapted to produce homogeneous polymers, copolymers, terpolymers, etc., for example, homogeneous polyethylene, homogeneous poly(ethylene-octene) copolymers and the like. The invention further includes the process of preparing the supported catalyst compositions and a process for preparing olefinic polymers using these catalyst compositions.

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: A catalyst composition comprising A) an aluminoxane-impregnated support prepared by contacting an aluminoxane with an inert carrier material and heating to a temperature of at least about 80.degree. C.; B) a metallocene of the formula:(L).sub.y (L')MY.sub.(x-y-1)wherein M is a metal from groups IIIB to VIII of the Periodic Table; each L and L' is independently a cycloalkadienyl group bonded to M; each Y is independently hydrogen, an aryl, alkyl, alkenyl, alkylaryl, or arylalkyl radical having 1-20 carbon atoms, a hydrocarboxy radical having from 1-20 carbon atoms, a halogen, RCO.sub.2 --, or R.sub.2 N--, wherein R is a hydrocarbyl group containing 1 to about 20 carbon atoms; n and m are each 0, 1, 2, 3, or 4; y is 0, 1, or 2; x is 1, 2, 3, or 4; and x-y.gtoreq.1; C) a bulky aluminum alkyl of the formula:AlR.sup.1.sub.x R.sup.2.sub.(3-x)wherein R.sup.1 is a hydrocarbyl group having 1 to 12 carbon atoms; x is an integer from 0 to 2; R.sup.2 is a hydrocarbyl group of the formula --(CH.sub.2).sub.y -- R.sup.

Abstract: Catalyst compositions comprising both metallocene complexes having polymerisable groups and polymerization catalysts eg Ziegler-Natta may be used for the preparation of polyolefins. The catalyst compositions may comprise the metallocene complex in the form of a polymer and may suitably be supported on inorganic supports. Polymers having a wide range of molecular weights and comonomer distributions may be prepared by use of the catalyst compositions. Preferred metallocene complexes are zirconium complexes in which the polymerisable group is vinyl.

Abstract: Procedure for the preparation of a solid catalyst component which is active in the polymerization of olefins, comprising the steps:a) contacting a silylated silica support with a solution of Mg-halide or Mg-alkyl-halide or a mixture of both,b) contacting the catalyst-precursor obtained in (a) with Mg-alkyl or Mg-alkyl-halide or a mixture of both, optionally in presence of electron-donors (Lewis bases),c) halogenating the catalyst-precursor obtained in (b) by contact of said activated support with halogenating agents,d) titanating the catalyst-precursor obtained in (c) with Ti-tetrahalide in the presence of electron-donors,e) recovering the solid catalyst-component from the reaction products of step (d).The catalyst component, which is obtained according to the above procedure, may also be used together with Al-trialkyl or Al-alkyl-halides and a Lewis base, as a catalyst for the polymerization of olefins.

Abstract: The solid catalytic component according to the invention is obtained bya) treatment of a catalytic component support with ZrCl.sub.4 or HfCl.sub.4 in the gas phase, followed by ab) treatment with a solution or suspension of a compound capable of grafting a group containing the cycloalkadienyl skeleton to the Zr or Hf contained in the support. Polymerization of olefins in the presence of such a catalytic component results in polymers with low polydispersities, which polymers are obtained with high productivities.

Abstract: An ethylene polymer having small values of Mw/Mn and Mz/Mw, a small proportion of long-chain branches and a high swell ratio and a process for preparing the polymer are disclosed. A solid titanium catalyst component obtained by initially contacting a solid titanium composite containing titanium, magnesium, halogen and a compound having at least two ether linkages present through plural atoms with an organometallic compound and then contacting the resulting product with oxygen is further disclosed. An ethylene polymerization catalyst comprising the above catalyst component and an organometallic compound catalyst component is furthermore disclosed. The ethylene polymer is excellent in moldability, and from this polymer, a molded article which is excellent in rigidity and impact resistance and free from poor appearance can be obtained. By the use of the ethylene polymerization catalyst, an ethylene polymer having excellent properties as mentioned above can be obtained.

Abstract: An ethylene/.alpha.-olefin copolymer obtained by copolymerizing ethylene with an .alpha.-olefin of 3 to 20 carbon atoms in the presence of a catalyst for olefin polymerization comprising an organoaluminum oxy-compound (a) and at least two kinds of transition metal compounds (b). This ethylene/.alpha.-olefin copolymer has high melt tension and high flowability.

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: The invention relates to a supported, prepolymerized metallocene catalyst system as well as its production and use in olefin polymerization. The method for producing the prepolymerized catalyst system involves prepolymerizing a metallocene catalyst system containing a volume of solution that is the equivalent of or less than the total pore volume of the supported catalyst system.

Abstract: Metal complexes useful as olefin polymerization catalysts corresponding to the formula: ##STR1## wherein: L is a delocalized, .pi.-bonded group that is bound to M, containing up to 50 nonhydrogen atoms;M is a metal of Group 3, 4 or the Lanthanide series of the Periodic Table of the Elements;Z is a covalently bound, divalent substituent of up to 50 non-hydrogen atoms having the formula, --(ER.sub.2).sub.m --, wherein E independently each occurrence is carbon, silicon or germanium, R independently each occurrence is selected from the group consisting of C.sub.1-20 hydrocarbyl, and C.sub.1-20 hydrocarbyloxy, with the proviso that in at least one occurrence R is C.sub.

Abstract: A catalyst for producing a poly-.alpha.-olefin which comprises a metallocene compound containing an element of group IVA bonded to an organic polymer containing an element of the group IVB; and a process for producing a poly-.alpha.-olefin which comprises polymerizing an .alpha.-olefin in the presence of the above-described catalyst and also a specified aluminoxane as a co-catalyst.

Abstract: An olefin polymerization catalyst composition is prepared by adding an organometallic compound of a group IA to IIIA metal to a procatalyst containing a support impregnated with TiCl.sub.4 but without using free TiCl.sub.4 to impregnate the support. The procatalyst is prepared by stirring a carrier with magnesium dichloride and a titanium tetralkoxide in a hydrocarbon solvent containing an electron donor, evaporating the solvent and the donor to form a free-flowing powder and chlorinating the titanium tetralkoxide with an alkyl aluminum chloride.

Abstract: Catalyst compositions are provided that comprise (a) discrete silica particles; (b) chromium; and (c) a support comprising silica. These composition are useful in polymerizing ethylene or copolymerizing ethylene with a comonomer and provide better control over the molecular weight and the molecular weight distribution of a resulting polymer.

Abstract: A catalyst prepared by firstly depositing a large amount of aluminoxane on a particulate support, then depositing a small amount of monocyclopentadienyl zirconium trihalide on the support. The catalyst is active for the polymerization of ethylene, optionally with a minor amount of other alpha olefins such as butene or hexene, particularly in a gas phase process.