Abstract: The present invention concerns a method for the copolymerization of conjugated diolefins and vinyl-aromatic monomers in the presence of rare-earth catalysts and the use of the copolymers in rubber mixtures for tire applications.

Abstract: A novel supported catalyst component useful for &agr;-olefin polymerization and a method of polymerizing an &agr;-olefin using the same. The catalyst component is characterized by being prepared by contacting a complex represented by general formula (I) wherein R1 and R2 are the same or different and each represents a C1-6 linear or branched alkyl, a C1-3 haloalkyl, or optionally substituted phenyl; and X represents a halogeno with magnesium compound.

Abstract: The invention relates to high-activity catalysts for olefin polymerization, to efficient methods for producing them, and to efficient methods of using the catalysts for producing high-quality polyolefins. The olefin polymerization with the catalysts does not require a large amount of an organic aluminium compound, and the residual metal in the polyolefins produced is much reduced. The catalysts are characterized by containing a product as prepared by contacting any of clay, a clay mineral and an ion-exchanging layered compound, an organic silane compound, and water with each other, or by containing a silane compound-processed clay.

Abstract: A process for producing polymer in a gas phase reactor by introducing a stream of monomer and gas into a polymerization zone while providing at least one liquid component in the polymerization zone.

Abstract: The present invention relates to a process for the preparation of random copolymers of propylene with c2-c10&agr;-olefins, carried out in the presence of a catalyst comprising: A) A solid component comprising a titanium compound supported on mgcl2 in active form and an electron-donor compound; b) An alkyl-al compound, and c) An electron-donor compound selected from the group of 1,3-diethers. The copolymers obtained using the said process show, for an equivalent content of &agr;-olefin, a lower content of xylene-soluble fractions when compared with the copolymers obtained with the catalysts of the prior art.

Abstract: Processes are provided that produce organo-aluminoxane compositions. Said processes comprise: desiccating a first mixture, where said first mixture comprises organo-aluminoxane molecules intermixed with a solvent, to produce a first composition, where said first composition comprises organo-aluminoxane molecules; mixing said first composition with a solvent to produce a second mixture, where said second mixture comprises organo-aluminoxane molecules and said solvent; contacting said second mixture with a insolublization agent to produce said organo-aluminoxane compositions. A polymerization process using a catalyst that comprises an organo-aluminoxane composition is also provided.

Abstract: A method to prepare a polyolefin in the presence of a catalyst comprising: (A) a solid catalyst component prepared by reacting a homogenous solution consisting of (i) at least one member selected from the group consisting of metal magnesium and a hydroxylated organic compound, and oxygen-containing organic compounds of magnesium, (ii) at least one oxygen-containing organic compound of titanium and (iii) at least one silicon compound, first with (iv) at least one first organoaluminum halide compound of the formula: AlR5zX3−z  wherein R5 is a hydrocarbon group having from 1 to 20 carbon atoms, X is a halogen atom, and 1≦z≦2, and wherein the atomic ratio of gram atoms of Al in the component (iv) to gram atoms of Mg in the component (i) (Al/Mg) is from 0.1 to 2.

Abstract: Novel compounds are disclosed comprising the skeletal unit depicted in Formula (I) wherein O is oxygen; N is nitrogen; R1 is hydrogen, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl; R3, R4, R5 and R6 are hydrogen or hydrocarbyl or heterohydrocarbyl groups containing 1 to 10 carbon atoms and the R12 groups are independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl, heterocarbyl and substituted heterocarbyl; A is carbon or silicon; and r is 1 or more; M is scandium, yttrium, or a Group IV or Group V metal or a lanthanide or actinide; T is the oxidation state of M and is II or greater; X represents a monodentate atom or group covalently or ionically bonded to M; L is a mono- or bidentate molecule datively bound to M, and n is from 0 to 5.

Abstract: Solid catalyst components for the polymerization of olefins, comprising titanium, magnesium and a compound of general formula (I), wherein R1 and R2 may be the same or different and each represents a linear or branched hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 1 to 10, as an electron donor, which are combined with organoaluminum compounds to form polymerization catalysts for the production of olefin polymers. This electron donor has no problems of safety and hygiene, and is inexpensive and easily synthesized. This compound can provide highly active and highly stereoregular solid catalyst components for the polymerization of olefins, catalysts for the polymerization of olefins, and processes for producing olefin polymers.

Abstract: A new class of initiators for inducing the cationic polymerization of olefins was discovered. These initiators, in conjunction with Lewis acids as coinitiators, effectively initiate the carbocationic polymerization of olefins.

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

Abstract: A novel copolymer useful for photoresist, which allows a formation of patterns showing a significantly improved resolution in a photolithography using ArF (193 nm) light source, is prepared by copolymerizing at least two cycloaliphatic olefins with an amide or imide.

Abstract: A novel process for producing homopolymers and interpolymers of olefins which involves contacting an olefin and/or an olefin and at least one or more other olefin(s) under polymerization conditions with an olefin polymerization catalyst and at least one ether comprising at least one carbon-oxygen-carbon linkage (C—O—C) of the formula R1—O(—R2—O)m—R3 in amounts sufficient to reduce the electrostatic charge in the polymerization medium. Also disclosed is a process for reducing electrostatic charge in an olefin polymerization medium.

Abstract: The invention relates to a norbornene polymer containing repeating units formed from a norbornene monomer in its main chain and having a weight average molecular weight (Mw) ranging from 10,000 to 1,000,000 and a ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) ranging from 1.60 to 1.95, and a production process thereof.

Abstract: Conjugated diolefins, optionally in combination with other unsaturated compounds which may be copolymerized with the diolefins, are polymerized by performing the polymerization of the diolefins in the presence of catalysts based on cobalt compounds, organoaluminum compounds and modifiers in the presence of aromatic vinyl compounds at temperatures of −30° C. to +80° C. By means of the process according to the invention, it is possible straightforwardly to produce solutions of polydiolefins, such as polybutadiene, having different 1,2 unit contents in aromatic vinyl compounds, which solutions may then, for example, be further processed to yield ABS or HIPS.

Abstract: This invention is based upon the unexpected discovery that elastomeric trans-1,4-polybutadiene can be made by utilizing a catalyst system that is comprised of an organocobalt compound, an organoaluminum compound, a para-alkyl substituted phenol, and ortho-phenyl phenol wherein the molar ratio of the para-substituted phenol to the organoaluminum compound is within the range of about 1.2:1 to about 1.8:1, and wherein the molar ratio of the ortho-phenyl phenol to the organoaluminum compound is within the range of about 0.7:1 to about 1.3:1. Accordingly, the elastomeric trans-1,4-polybutadiene made by the process of this invention does not need to be heated, such as in a hot-house, before being used in making rubber stocks.

Abstract: Oily hyperbranched polymers derived from ethylene, propylene, butene and/or a C5-C24 &agr;-olefin, and a method for their synthesis, are disclosed. The polymers have non-regular microstructures and are characterized by a ratio ()of methyl hydrogens centered around 0.85 ppm on the 1H-NMR spectra of the polymers relative to total aliphatic hydrogens of from about 0.40 to about 0.65 for polymers derived from ethylene or butene, and a ratio ()of from greater than 0.50 to about 0.65 for polymers derived from propylene. A method for grafting hyperbranched polymers derived from ethylene, propylene, butene and/or a C5-C24 &agr;-olefin onto aromatic rings in organic molecules and polymers, and the resulting grafted materials, are also disclosed. The hyperbranched polymers and grafted materials are useful, for example, as lubricants and lubricant additives.

Abstract: The present invention relates to catalysts for the polymerization of ethylene and its mixtures with olefins CH2═CHRVIII, comprising the reaction product of a solid catalyst component containing Ti, Mg and halogen, an alkyl-Al compound and a particular electron donor compound selected from the compounds containing at least two oxygen atoms bonded to different carbon atoms and selected by standard tests of reactivity with triethyl-Al and MgCl2 compounds. The catalyst of the invention are used in processes for the (co)polymerization of ethylene to prepare (co)polymers having narrow molecular weight distribution (MWD).

Abstract: A novel process for producing homopolymers and interpolymers of olefins which involves contacting an olefin and/or an olefin and at least one or more other olefin(s) under polymerization conditions with at least one Ziegler-Natta catalyst comprising a component comprising at least one transition metal and a co-catalyst comprising at least one organometallic compound and at least one compound comprising at least one carbon-oxygen-carbon linkage (C—O—C) of the formula R1—O(—R2—O)m—R3 in amounts sufficient to reduce the electrostatic charge in the polymerization medium. Also disclosed is a process for reducing electrostatic charge in an olefin polymerization medium.

Abstract: A novel process for the polymerization of olefins is provided. The process involves contacting at least one olefin with a Ziegler-Natta catalyst in the presence of dinitrogen monoxide in the production of polymeric products having a narrower molecular weight distribution. A process for narrowing molecular weight distribution of polyolefins utilizing dinitrogen monoxide is also provided.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients including an iron-containing compound, a hydrogen phosphite, and a mixture of two or more organoaluminum compounds. This catalyst composition is particularly useful for polymerizing conjugated dienes. When this catalyst composition is used to polymerize 1,3-butadiene into syndiotactic 1,2-polybutadiene the ratio of the organoaluminum compounds can be adjusted to vary the melting temperature and molecular weight of the polymer product.

Abstract: A new class of initiators for inducing the cationic polymerization of olefins was discovered. These initiators, in conjunction with Lewis acids as coinitiators, effectively initiate the carbocationic polymerization of olefins. The new initiators are epoxides with the general formula where R1, R2 and R3 are hydrogen, alkyl, aryl or aralkyl groups, and can be the same or different, and i is a positive whole number. The Lewis acid has the general formula of MtXn, where M is titanium, aluminum, boron or tin, X is a halogen, an alkyl or an alcoxy or a mixture thereof. The process is a carbocationic process, which can be living or non-living, at a temperature of from about 0 to −80 C. The polymer produced can be a homo- or copolymer (random or block) carrying hydroxy functional groups.

Abstract: This invention relates to a process for polymerizing isobutene using a catalytic system comprising a transition metal compound, a benzene derivative compound, and methylaluminoxane, and the catalytic system applied to the polymerization of isobutene, (1) the added benzene derivative compound and methyl aluminoxane to the transition metal species provides higher stability of cation active site so that polyisobutene with a high molecular weight can be produced even at a higher reaction temperature than the conventional cationic polymerization temperature; (2) nonhalogen solvent such as toluene can be employed as a polymerization solvent instead of halogenated solvents such as methyl chloride; and (3) under the stable catalytic system, a final product with a high yield can be ensured for its long-term use.

Abstract: A high molecular weight polyethylene prepared by preliminary polymerization is added at the time of main polymerization of an olefin, for example, propylene, to prepare an olefin (co)polymer composition comprising the above high molecular weight polyethylene finely dispersed as fine particles in the polyolefin, such as polypropylene, and a cross-linked structure is formed in the olefin (co)polymer composition. This process can provide a modified olefin (co)polymer composition improved in the strength in a molten state in terms of melt tension or the like and in crystallization temperature and excellent in moldability such as high-speed producibility, and a molded modified olefin (co)polymer composition excellent in properties such as heat resistance and rigidity.

Abstract: A process for preparing a catalyst support in which a hydrophilic inorganic oxide of an element of main groups 2, 13 or 14 or transition group 4 of the Periodic Table or a mixture or mixed oxide thereof is dried at from 110 to 800° C., subsequently reacted, if desired, with alumioxanes or aluminum alkyls and subsequently reacted simultaneously with aluminoxanes and bisphenol A as a polyfunctional organic crosslinker. In a further stage, the catalyst support can be brought into contact with a polyolefin catalyst, giving a supported polyolefin catalyst which is used, in particular, for the polymerization of olefins.

Abstract: Readily filterable and deodorizable aqueous dispersions of pressure-sensitive adhesive, especially for self-adhesive labels, having solids contents of more than 65%, can be prepared with readily reproducible properties by copolymerizing esters of acrylic and/or methacrylic acid in the presence of less than 50 ppm of inhibitor and, preferably, in the presence of from 0.01 to 5% by weight of reducing agent by a special emulsion technique. The highly concentrated pressure-sensitive adhesive dispersion, subsequently deodorized with steam, is free from coagulum and seediness.

Abstract: A process for producing light alpha olefins by ethylene oligomerisation in contact with a catalyst produced by mixing a zirconium compound with an organic compound selected from the group formed by acetals and ketals, with an aluminum hydrocarbyl compound selected from the group formed by chlorine-containing or bromine-containing aluminum hydrocarbyl compounds and with an aluminum hydrocarbyl compound selected from tris-(hydrocarbyl)-aluminum compounds.

Abstract: A novel process for producing homopolymers and interpolymers of olefins which involves contacting an olefin and/or an olefin and at least one or more other olefin(s) under polymerization conditions with a Ziegler-Natta catalyst and dinitrogen monoxide in an amount sufficient to reduce the electrostatic charge in the polymerization medium. Also provided is a process for reducing electrostatic charge in the polymerization of an olefin by adding dinitrogen monoxide.

Abstract: A catalyst for the polymerization of vinylaromatic monomers, and particularly styrene, with a high yield and a high syndiotacticity index, comprises the product consisting of the following two components in contact with each other: A) an &eegr;5-cyclopentadienyl complex of titanium; B) an organo-oxygenated compound of aluminum; and contains a sufficient amount of at least one carboxylated product having the following general formula: R—COO—G  (I) wherein R—COO is a carboxylic group comprising the organic radical R having from 1 to 30 carbon atoms, and G represents a hydrogen atom, an aliphatic or aromatic hydrocarbon group having from 1 to 20 carbon atoms or a metal atom, possibly substituted, linked to said carboxylic group.

Abstract: The present invention relates to a catalyst composition and a method for making the catalyst composition of a polymerization catalyst and a carbonyl compound. The invention is also directed to the use of the catalyst composition in the polymerization of olefin(s). In particular, the polymerization catalyst system is supported on a carrier. More particularly, the polymerization catalyst comprises a bulky ligand metallocene-type catalyst system.

Abstract: The present invention relates to a catalyst system comprising: a) an organoaluminum compound, b) a metal compound selected from subgroups IV to VI of the periodic system, c) a reactivator in a molar ratio of 0.5 to 100 relative to compound b), wherein said reactivator comprises a characterized in that a mono- or dihalocarboxylic acid alkyl ester of the following formula: wherein X is a C1-6 alkyl or C1-6 alkoxy group, Y is Cl, Br or H, Z is Cl or Br and R is a C1-6 alkyl group.

Abstract: In catalyst systems of the Ziegler-Natta type modified during their preparation and comprising as active constituentsa) a titanium-containing solid component which is obtained by reacting a compound of titanium with a compound of magnesium, a halogen, an inorganic oxide as support, a C.sub.1 -C.sub.8 -alkanol and a carboxylic ester as electron donor compound,and also as cocatalystb) an aluminum compound andc) if desired, a further electron donor compound,the titanium-containing solid component a) is prepared by first, in a first stage, admixing an inorganic oxide as support with a solution of a chlorine-free compound of magnesium in an inert solvent, stirring this mixture for from 0.5 to 5 hours at from 10 to 120.degree. C. and subsequently reacting it while stirring continually in an inert solvent with a C.sub.1 -C.sub.8 -alkanol in an at least 1.

Abstract: This invention is generally directed toward a supported catalyst system useful for polymerizing olefins. The method for supporting the catalyst of the invention provides for a supported metallocene catalyst which when utilized in a polymerization process substantially reduces reactor fouling and sheeting in a gas or slurry polymerization process.

Abstract: An .alpha.-olefin polymerization catalyst which comprises:(A) a solid catalyst component containing a tetra-valent titanium obtained by treating a magnesium compound having an Mg--O bond in its molecule with a titanium halide;(B) an organoaluminum compound; and(C) an organosilicon compound represented by the general formula R.sup.1 R.sup.2 Si(OR.sup.3).sub.2wherein R.sup.1 represents a hydrocarbon group having 4 to 30 carbon atoms wherein a carbon bonded directly to Si is a tertiary carbon, R.sup.2 represents a straight chain hydrocarbon group having 2 to 10 carbon atoms and R.sup.3 represents a hydrocarbon group having 1 to 10 carbon atoms, or the general formula R.sup.4 R.sup.5 Si(OR.sup.6).sub.2wherein R.sup.4 and R.sup.5 are hydrocarbon groups having an alicyclic hydrocarbon having 5 carbon atoms as a basic structure, R.sup.4 and R.sup.5 may be the same or different, and R.sup.6 represents a hydrocarbon group having 1 to 10 carbon atoms, and a process for producing .alpha.-olefin with said catalyst.

Abstract: The present invention provides a novel catalyst system which can be preferably used in the trimerization, oligomerization reaction or polymerization reaction of an olefin, and a method for the trimerization, oligomerization or polymerization reaction of an olefin, which comprises using the catalyst system. A catalyst system obtained by contacting the following components (A) to (C):(A) a chromium compound,(B) an imine compound, and(C) a metal alkyl compound, and a method for the trimerization, oligomerization or polymerization reaction of an olefin, which comprises using the catalyst system are disclosed.

Abstract: This invention is generally directed toward a supported catalyst system useful for polymerizing olefins. The method for supporting the catalyst of the invention provides for a supported bulky ligand transition metal catalyst which when utilized in a polymerization process substantially reduces the reactor fouling and sheeting in a gas, slurry or liquid pool polymerization process.

Abstract: This invention is generally directed toward a supported catalyst system useful for polymerizing olefins. The method for supporting the catalyst of the invention provides for a supported metallocene catalyst which when utilized in a polymerization process substantially reduces reactor fouling and sheeting in a gas or slurry polymerization process.

Abstract: This invention is generally directed toward a supported catalyst system useful for polymerizing olefins. The method for supporting the catalyst of the invention provides for a supported bulky ligand transition metal catalyst which when utilized in a polymerication process substantially reduces the reactor fouling and sheeting in a gas, slurry or liquid pool polymerization process.

Abstract: A catalytic composition for the production of light alpha olefins by ethylene oligomerisation is produced by mixing a zirconium compound with an organic compound selected from the group formed by acetals and ketals, with an aluminium hydrocarbyl compound selected from the group formed by chlorine-containing or bromine-containing aluminium hydrocarbyl compounds and with an aluminium hydrocarbyl compound selected from tris-(hydrocarbyl)-aluminium compounds. Addition of a tris-(hydrocarbyl)-aluminium compound greatly increases the activity. A process for producing light alpha olefins by ethylene oligomerisation is also claimed.

Abstract: The present invention provides a Ziegler-Natta catalyst based on titanium and vanadium useful in solution processes for the polymerization of olefins having a low amount of aluminum and magnesium. The catalysts of the present invention have a molar ratio of magnesium to the first aluminum component from 4.0:1 to 8.0:1 and molar ratio of magnesium to titanium and vanadium from 4.0:1 to 8.0:1. The invention provides a novel catalyst preparation method to substantially increase the polymer molecular weight in the high temperature ethylene polymerization process.

Abstract: By utilizing the vapor phase polymerization techniques of the present invention, numerous distinct and highly beneficial advantages are realized. For instance, cis-1,4-polyisoprene rubber and high cis-1,4-polybutadiene rubber having a consistent and controllable molecular weight can be easily and practically prepared without utilizing a solvent. The subject invention more specifically discloses a method for vapor phase polymerizing isoprene into cis-1,4-polyisoprene in a process comprising the steps of:(1) charging into a reaction zone said isoprene and a preformed catalyst system which is made by reacting an organoaluminum compound with titanium tetrachloride, preferably in the presence of at least one ether; wherein the isoprene is maintained in the vapor phase in said reaction zone by a suitable combination of temperature and pressure;(2) allowing said isoprene to polymerize into cis-1,4-polyisoprene at a temperature within the range of about 35.degree. C. to about 70.degree. C.

Abstract: A method for producing a catalyst for the polymerization or copolymerization of olefins is described. The method includes producing a magnesium compound solution by reacting a magnesium halide compound in the mixture of a cyclic ether and two alcohols with an organosilane compound. The magnesium compound solution may be reacted with a titanium halide compound such that precipitated solid components are formed. These precipitated solid components may be reacted with a titanium compound and an electron donor to produce the polymerization catalyst.

Abstract: This invention relates to an initiator system for the polymerization of isoolefins having 4 to 16 carbon atoms, optionally with monomers polymerizable with isoolefins, the system consisting of or one or more aromatic or heteroaromatic, polycyclic hydrocarbons and an aged, organic solution of vanadium tetrachloride, wherein the concentration of the vanadium tetrachloride is 0.01 mmol to 500 mmol per liter of solvent and the molar ratio of aged vanadium tetrachloride to polycyclic hydrocarbons is in the range from 100:1 to 1:100.It is possible by means of the initiator system according to the invention to produce polyisoolefins, in particular butyl rubbers, at relatively high temperatures with only a low gel content and of a sufficiently high molecular weight.

Abstract: This invention relates to a process for controlling the molecular weight distribution of high 1,4-cis polybutadiene and more particularly, to a process of easily controlling the molecular weight distribution of polybutadiene which is concerned directly with the physical properties such as processability, in such a manner that preparation of high 1,4-cis polybutadiene is made available via polymerization of 1,3-butadiene in the presence of Ziegler-Natta catalyst, adding carboxylic acid represented by following formula I for the controlling of the molecular weight distribution of polybutadiene based on the contents of carboxylic acid, may be easily controlled, without any alternation in the 1,4-cis contents. ##STR1## Wherein R is selected from the group consisting of alkyl, cycloalkyl and arylalkyl groups substituted or unsubstituted with at least one or more halogen atoms, or alkyl, cycloalkyl and arylalkyl groups with at least one or more double bonds containing from 5 to 20 carbon atoms.

Abstract: There is provided a process for producing polydienes, such as polybutadiene and polyisoprene, in a gas phase fluidized bed reactor using a pre-activated nickel catalyst which is highly active for cost effective production of these dienes in gas phase.

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: The synthesis of cis-1,4-polyisoprene by polymerizing isoprene with a catalyst system which is comprised of a titanium tetrahalide, a trialkylaluminum compound and diphenylether is plagued with the formation of gel. This invention is based upon the unexpected discovery that gel formation can be reduced by conducting such polymerizations in the presence of a diarylamine, such as para-styrenated diphenylamine. The subject invention more specifically discloses a process for synthesizing cis-1,4-polyisoprene having a low gel content which comprises polymerizing isoprene in an inert organic solvent with a preformed catalyst system which is made by reacting an organoaluminum compound with titanium tetrahalide, such as titanium tetrachloride, in the presence of at least one ether, wherein said polymerization is conducted at a temperature which is within the range of about 0.degree. C. to about 100.degree. C., and wherein said polymerization is conducted in the presence of a diarylamine.

Abstract: Diene rubbers are produced in the gas phase by first polymerizing the dienes or diene mixtures in the presence of a catalyst system, which is based on rare earth compounds, at temperatures of from 0 to 150.degree. C. and at pressures of from 1 mbar to 50 bar, so that a pourable diene rubber having a Mooney viscosity ML (1+4', 100.degree. C.) of 70 to 180 Mooney units is obtained, and subsequently subjecting the pourable diene rubber obtained to a chemical or thermal decomposition reaction until a Mooney viscosity of 10 to 70 Mooney units is obtained.

Abstract: Catalyst systems which are suitable for polymerizing olefinically unsaturated compounds comprise as active constituentsA) a metallocene complex of the metals of the fourth, fifth or sixth transition group of the Periodic Table of the Elements,B) a compound forming metallocenium ions andC) a sterically hindered, organic Lewis base.

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.