Abstract: An ethylene polymerization process is disclosed. The process uses a single-site catalyst that contains a boraaryl ligand. It comprises supporting the catalyst, forming a slurry of the supported catalyst in an organic solvent, mixing the catalyst slurry with trialkyl aluminum compound, and polymerizing ethylene in the presence of the trialkyl aluminum-treated catalyst slurry. The process gives polyethylene having a controlled long-chain-branch index.

Abstract: A catalytic polymerization process for preparing polymer products is provided. The polymerization process is either homopolymerization of olefins or copolymerization of olefins with alpha-olefins. The polymerization process is conducted in the presence of a solid catalyst precursor and a cocatalyst. The catalyst precursor includes a transition metal, a magnesium compound, an aluminum compound and a polyvinylchloride (PVC) support.

Abstract: An olefin polymerization process is described. The process comprises preparing a catalyst system by premixing a first organoaluminum with a supported boraaryl catalyst and then polymerizing an olefin in the presence of the premixed supported catalyst, an activator and a second organoaluminum. The process produces polyolefins having broad and/or bimodal molecular weight distributions compared to the process in which either the first or the second organoaluminum is not used.

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 present invention relates to a chemical compound of the formula A The compound can be employed as a catalyst component for the polymerization of olefins.

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: A catalyst precursor having the formula:

Abstract: The present invention relates to a continuous method of preparing a block-graft or star-shaped copolymer. This method involves providing a living polymer, mixing the living polymer with a first monomer under conditions effective to produce a block copolymer, wherein the first monomer includes a polymerization site and a polymerization initiation site, and mixing the block copolymer with a second monomer under conditions effective to produce a block-graft or star-shaped copolymer. The present invention also relates to a continuous method of preparing a graft or graft-block copolymer.

Abstract: A solid catalyst for olefin polymerization, obtained by reacting a least one of a hydropolysiloxane compound, having the formula R1aHbSiO(4−a−b)/2, a silane compound of formula R2cSi(OH)4−c, and condensates of the silane, with a compound of formula (MgR32)p.(R3MgX)q to form a reaction product. The reaction product is reacted with an alcohol, having 1 to 4 carbon atoms, to obtain an intermediate product. The intermediate product, is then reacted with water to obtain reaction product. An organoaluminum oxy compound and a metallocene compound are carried on the solid reaction product. The solid catalyst may be used for olefin polymerization. The catalyst requires no deashing treatment and produces a polymer having high bulk density and narrow particle size distribution. Thus the solid catalystenables control of particle size of the polymer in a simple easy manner, and shows no adhesion of polymer onto the inner wall of autoclave.

Abstract: The present invention includes novel ligands which may be utilized as part of a catalyst system. A catalyst system of the present invention is a transition metal-ligand complex. In particular, the catalyst system includes a transition metal component and a ligand component comprising a Nitrogen atom and/or functional groups comprising a Nitrogen atom, generally in the form of an imine functional group. In certain embodiments, the ligand component may further comprise a phosphorous atom. Preferred ligand components are bidentate (bind to the transition metal at two or more sites) and include a nitrogen-transition metal bond. The transition metal-ligand complex is generally cationic and associated with a weakly coordinating anion.

Abstract: Supported catalyst systems are obtainable by A) reaction of an inorganic carrier with a metal compound of the general formula I M1(R1)r(R2)s(R3)t(R4)u  I  where M1 is an alkali metal, an alkaline earth metal or a metal of main group III or IV of the Periodic Table, R1 is hydrogen, Ch1-C10-alkyl, C6-C15-aryl, alkylaryl or arylalkyl each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, R2 to R4 are each hydrogen, halogen, C1-C10-alkyl, C6-C15-aryl, alkylaryl, arylalkyl, alkoxy or dialkylamino each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, r is an integer from 1 to 4 and s, t and u are integers from 0 to 3 the sum r+s+t+u corresponding to the valency of M1, B) reaction of the material obtained according to A) with a metallocene complex in its metal dihalide form and a compound forming metallocenium ions and C) subsequent reaction with a metal compound of the general formula I

Abstract: A catalyst precursor having the formula: AqMLn wherein each A has the formula: M is a metal selected from the group consisting of Group 3 to 13 elements and Lanthanide series elements; each L is a monovalent, bivalent, or trivalent anion; X and Y are each heteroatoms; Cyclo is a cyclic moiety; each R1 is a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group 13 to 17 elements, and two or more adjacent R1 groups may be joined to form a cyclic moiety; each R2 is a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group 13 to 17 elements, and two or more adjacent R2 groups may be joined to form a cyclic moiety; Q is a bridging group; each m is independently an integer from 0 to 5; n is an integer from 1 to 4; q is 1 or 2; and when q is 2, the A groups are optionally connected by a bridging group Z is provided. The catalyst precursor may be made by reacting an organometal compound with a heteroatom-containing ligand.

Abstract: The present invention relates to a catalyst for polymerization of &agr;-olefin, which comprises:

Abstract: The present invention provides a process for the production of a conjugated diene polymer having a controlled microstructure at a high polymerization activity in the presence of a metallocene type complex of compound of transition metal of the group V of the Periodic Table. A novel catalyst is provided comprising (A) a metallocene type complex of a transition metal of the group V of the Periodic Table, (B) an ionic compound of a non-coordinating anion and a cation, (C) an organic metal compound of the groups I to III and (D) water, wherein the molar ratio of (C)/(D) is from 0.66 to 5.

Abstract: A catalyst activator particularly adapted for use in the activation of metal complexes of metals of Group 3-10 for polymerization of ethylenically unsaturated polymerizable monomers, especially olefins, comprising: a compound corresponding to the formula: ArfzAl2Q16-z where; Q1 independently each occurrence is selected from C1-20 alkyl; Arf is a fluorinated aromatic hydrocarbyl moiety of from 6 to 30 carbon atoms; z is a number greater than 0 and less than 6, and the moiety: ArfzAl2Q16-z is an adduct of tri(fluoroarylaluminum) with from a sub-stoichiometric to a super-stoichiometric amount of a trialkylaluminum having from 1 to 20 carbons in each alkyl group.

Abstract: It is known to polymerize olefins using transition metal complexes and/or compounds. There is an ongoing search for catalysts for olefin polymerization which do not rely on transition metals as the active center. The present invention provides novel aluminum phosphinimine complexes which are useful in the polymerization of olefins.

Abstract: A solid cocatalyst is prepared by reacting a suitable support base with an organoaluminum compound and then reacting that product with an activity promoting amount of water. The solid cocatalyst can be combined with a polymerization catalyst to form a catalyst system useful for the polymerization of olefins.

Abstract: A process for starting a polymerization of butadiene to produce polybutadiene in a gas phase reactor having a seed bed which comprises (i) passivating the reactor and the seed bed by introducing an aluminum alkyl having a concentration ranging from about 2,000 to 20,000 ppm and (ii) feeding the catalyst and co-catalyst to the reactor before the addition of the butadiene.

Abstract: A catalyst composition for preparing high-syndiotacticity polystyrene polymers which comprises: (a) a titanium complex represented by the following formula of TiR′1R′2R′3R′4 or TiR′1R′2R′3, wherein R′1, R′2, R′3, and R′4 are, independently, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group, a hydrogen atom, or a halogen atom; (b) a cyclopentadienyl complex represented by the following formula: wherein R1-R13 are, independently, alkyl group, aryl group, silyl group, halogen atom, or hydrogen atom; Ra and Rb are, independently, alkyl group, aryl group, alkoxy, aryloxy group, cyclopentadienyl group, hydrogen atom, or halogen atom; and Xa is a Group IIA element and Xb is a Group IIIA element.

Abstract: The instant invention teaches a method for forming a syndiotactic 1,2-polybutadiene product having a syndiotacticity of more than 66.5% and a melting temperature of more than about 100° C. The method includes polymerizing 1,3-butadiene in solution with a solvent, in the presence of catalytically effective amounts of: (a) an organomagnesium compound; (b) a chromium compound; and, (c) a dihydrocarbyl hydrogen phosphite. The present invention also contemplates a product of the method and an article made from the product.

Abstract: The present invention provides catalyst systems useful in the polymerization of olefins comprising a transition metal component and a ligand component comprising a Nitrogen atom and/or functional groups comprising a Nitrogen atom, generally in the form of an imine functional group. In certain embodiments, the ligand component may further comprise a phosphorous atom. Preferred ligand components are bidentate (bind to the transition metal at two or more sites) and include a nitrogen-transition metal bond. The transition metal-ligand complex is generally cationic and associated with a weakly coordinating anion. In a preferred embodiment, the catalyst system of the present invention further comprises a Lewis or Bronsted acid complexed with the ligand component of the transition metal-ligand complex.

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: A blow-moldable or extrudable ethylene polymer having an excellent moldability which gives a molded product free of roughened surface, having: a number-average molecular weight Mn (V1) as determined from the amount of a terminal vinyl group by .sup.13 C-NMR measurement with respect to a fraction having a number-average molecular weight Mn of 100,000 according to GPC; and a number-average molecular weight Mn (V2) as determined from the amount of a terminal vinyl group by .sup.13 C-NMR measurement with respect to a fraction having a number-average molecular weight Mn of 10,000 according to GPC, Mn(V1) and Mn(V2) satisfying the following relationship:1.01.ltoreq.log.sub.10 {Mn(V1)/Mn(V2)}.ltoreq.3.0and having a melt flow rate (HLMFR) of from 0.1 to 70 g/10 min.

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: Polymers of C.sub.2 -C.sub.12 -alkenes are prepared at from -50 to 300.degree. C. and from 0.5 to 3000 bar in the presence of a catalyst system by a process in which a compound of the general formula I ##STR1## where M.sup.1 is boron, aluminum, gallium, indium or thallium andR.sup.1 and R.sup.2 are each hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl, alkylaryl or arylalkyl each having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, or 5- to 7-membered cycloalkyl which in turn may carry C.sub.1 -C.sub.10 -alkyl as a substituent, or R.sup.1 and R.sup.2 together form a cyclic group, is added of 4 to 15 carbon atoms.

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: A propylene-1-butene copolymer wherein a Shore A-scale hardness measured according to ASTM D2240 is not more than 70 and an intrinsic viscosity [.eta.] measured in axylene solvent at the temperature of 70.degree. C. is not less than 0.3 and which shows no crystalline melting peak and no crystallization peak in differential scanning calorimeter (DSC) mesurement.

Abstract: The present invention provides a polymerization catalyst comprising (a) a specific transition metal compound, (b) (i) a compound which can form a complex by reaction with the transition metal compound of component (a) or (ii) a specific compound containing oxygen, and optionally, (c) an alkylating agent, and a process for producing polymers in the presence of said polymerization catalyst.By using the polymerization catalyst of the present invention, decrease in the contents of residual metals in obtained polymers, simplification of the process for producing polymers, and reduction of the production cost of polymers can be achieved, and polymers having a high molecular weight can be obtained.

Abstract: Amorphous and impact resistant co/ter-polymer made from olefins and aryl-substituted cyclic monomers by polymerizing using a catalyst, wherein the substituent is a phenyl- or indanyl-group and the catalyst is a metallocene-catalyst. Preferably said aryl-substituted cyclic monomer is phenyl-norbomene (5-phenyl-bicylo-2,2,1-hept-2-ene) or indanyl-norbomene (1,4-methano-1,4,4a,9a-tetrahydrofluorence).

Abstract: An ethylene base polymer and a preparation method of an ethylene base polymer characterized in use of a catalyst comprising a chromium amide compound, a solid inroganic oxide calcined at 100 to 500.degree. C. and alumoxane. According to the present invention, an ethylene base polymer with a wide molecular weight distribution, excellent shock and environmental stress cracking resistances, causing no melt fracture, and suitable for film forming and blow molding can be effectively prepared.

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

Abstract: An catalyst composition for preparing high-syndiotacticity polystyrene polymers which comprises: (a) a titanium complex represented by the following formula of TiR'.sub.1 R'.sub.2 R'.sub.3 R'.sub.4 or TiR'.sub.1 R'.sub.2 R'.sub.3, wherein R'.sub.1, R'.sub.2, R'.sub.3, and R'.sub.4 are, independently, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group, a hydrogen atom, or a halogen atom; (b) a cyclopentadienyl complex of silicon (Si), germanium (Ge), or tin (Sn) represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.

Abstract: A polymerization process for olefinically or acetylenically unsaturated monomers is disclosed. The process comprises contacting the one or more of the monomers with a suitable ionic catalyst system in the presence of a long-chain, linear alkyl ligand-containing organo aluminum compound. Preferred ionic catalysts are derived from 1) bridged hafnium compounds, 2) silicon bridged monocyclopentadienyl titanium compounds and 3) unbridged, bulky Group 15 containing, bulky monocyclopentadienyl titanium compounds, and a non-coordinating anion precursor compound. A class of preferred anion precursors consists of hydrated salts comprising a Group 1 or 2 cation and a non-coordinating anion. Using the preferred ionic catalysts high temperature processes, e.g., at or above 90.degree. C. can be conducted to prepare polyolefins, particularly ethylene copolymers, of both high molecular weight and high comonomer content.

Abstract: There is disclosed a process for producing a styrenic polymer which comprises polymerizing at least one styrenic monomer by the use of a polymerization catalyst comprising in combination (A) at least one transition metal compounds, (B) an aluminoxane, (C) a coordination complex compound comprising a cation and an anion in which a plurality of radicals are bonded to a metal and (D) an organoaluminum compound. The above process is capable of producing a styrenic polymer which has high degree of syndiotactic configuration and a wide range of molecular weight distribution and is minimized in residual metallic components at a low production cast with a high efficiency.

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: Certain olefins such as ethylene, .alpha.-olefins and cyclopentene can be polymerized by using catalyst system containing a nickel or palladium .alpha.-diimine complex, a metal containing hydrocarbylation compound, and a selected Lewis acid, or a catalyst system containing certain nickel ?II! or palladium ?II! compounds, an .alpha.-diimine, a metal containing hydrocarbylation compound, and optionally a selected Lewis acid. The process advantageously produces polyolefins useful for molding resins, films, elastomers and other uses.

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: Rubbery, amorphous cyclic olefin/.alpha.-olefin copolymers in a molar ratio from 5/95 to 30/70. The copolymers are rubbery and have the general properties of thermoplastic elastomers, e.g. good elastic recovery, toughness, and high elasticity, and have a relatively low glass transition temperature (Tg) to avoid brittleness and hardness under normal use temperature. The copolymers also have a high molecular weight, a narrow molecular weight distribution and a uniform, random comonomer distribution to impart a rubbery loss modulus plateau over the temperature range from Tg to above 100.degree. C., and are optionally lightly crosslinked or plasticized to further extend their useful temperature range.

Abstract: A catalyst component is disclosed for use in the homo- or copolymerization of olefinic hydrocarbons. The catalyst component is comprised of a first compound of the formula M.sup.1 (OR.sup.1).sub.p R.sup.2.sub.q X.sup.1.sub.4-p-q, M.sup.1 being titanium a second compound of the formula M.sup.2 (OR.sup.3).sub.m R.sup.4.sub.n X.sup.2.sub.z-m-n, with M.sup.2 being a metal of Groups Ia-IIIa or IIb of the Periodic Table, and a third compound which is an organocyclic compound having two or more conjugated double bonds. A process is also disclosed for the production of hydrocarbon polymers in which the above catalyst component is combined with a modified organoaluminum compound to form a catalyst composition capable of providing controlled molecular weight, wide distribution thereof and other desirable qualities in the polymer product.

Abstract: Metallocene catalysts and their preparation and use in the polymerization of olefins. Specifically, the catalysts and processes relate to polymerization of olefins in which an aluminum ionizing agent containing a triphenylcarbenium ion is utilized in preparing the catalyst. The preparation of an olefin polymerization catalyst comprising a metallocene-type catalyst and triphenylcarbenium tetrakis(pentafluorophenyl)aluminate is disclosed.

Abstract: There is disclosed a process for producing a styrenic polymer which comprises polymerizing at least one styrenic monomer by the use of a polymerization catalyst comprising in combination (A) at least one transition metal compounds, (B) an aluminoxane, (C) a coordination complex compound comprising a cation and an anion in which a plurality of radicals are bonded to a metal and (D) an organoaluminum compound. The above process is capable of producing a styrenic polymer which has high degree of syndiotactic configuration and a wide range of molecular weight distribution and is minimized in residual metallic components at a low production cast with a high efficiency.

Abstract: A polymerization process for olefinically or acetylenically unsaturated monomers is disclosed. The process comprises contacting the one or more of the monomers with a suitable ionic catalyst system in the presence of a long-chain, linear alkyl ligand-containing organo aluminum compound. Preferred ionic catalysts are derived from 1) bridged hafnium compounds, 2) silicon bridged monocyclopentadienyl titanium compounds and 3) unbridged, bulky Group 15 containing, bulky monocyclopentadienyl titanium compounds, and a non-coordinating anion precursor compound. A class of preferred anion precursors consists of hydrated salts comprising a Group 1 or 2 cation and a non-coordinating anion. Using the preferred ionic catalysts high temperature processes, e.g., at or above 90.degree. C. can be conducted to prepare polyolefins, particularly ethylene copolymers, of both high molecular weight and high comonomer content.

Abstract: Metallocene catalysts and their preparation and use in the polymerization of olefins. Specifically, the catalysts and processes relate to polymerization of olefins in which an aluminum ionizing agent containing a triphenylcarbenium ion is utilized in preparing the catalyst. The preparation of an olefin polymerization catalyst comprising a metallocene-type catalyst and triphenylcarbenium tetrakis(pentafluorophenyl)aluminate is disclosed.

Abstract: Syndiotactic 1,2-polybutadiene is a thermoplastic resin which has double bonds attached in an alternating fashion to its polymeric backbone. Films, fibers and molded articles can be made utilizing syndiotactic 1,2-polybutadiene. It can also be blended into rubbers and cocured therewith. It is generally preferred to synthesize syndiotactic 1,2-polybutadiene in an aqueous medium by suspension or emulsion polymerization. In such aqueous polymerization techniques reactor fouling and particle size control problems are frequently encountered. This invention is based upon the unexpected finding that reactor fouling can be greatly reduced or eliminated and that particle size can be regulated by conducting such aqueous polymerizations in the presence of a controlled amount of dissolved oxygen which is within the range of about 0.01 ppm to about 4 ppm.

Abstract: There is disclosed a process for producing a styrenic polymer, especially, syndiotactic polystyrene, which comprises polymerizing a styrenic monomer by the use of (a) a transition metal compound, (b) a coordination complex compound comprising an anion in which a plurality of radicals are bonded to a metal and a cation or methylaluminoxane, (c) an alkylating agent (alkyl group-containing aluminum, magnesium or zinc compound) and (d) a reaction product between a straight-chain alkylaluminum having at least two carbon atoms and water (alkylaluminoxane). The above process is capable of simplifying the production process and producing high-performance styrenic polymer having a high degree of syndiotactic configuration in high catalytic activity without deteriorating the catalyst activity, increasing the amounts of residual metals in the objective polymer or leaving the decomposition products of the alkylaluminum therein, thereby curtailing the production cost of the objective polymer.

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: The present invention relates to a process for controlling molecular weight of a styrenic polymer by adding an organometallic compound such as triethylaluminum when a crystalline styrenic polymer having a highly syndiotactic configuration is produced by using a catalyst for producing a styrenic polymer having the syndiotactic configuration. A styrenic polymer having a highly syndiotactic configuration can efficiently be obtained by homopolymerizing or copolymerizing a styrenic compound in accordance with the process of the present invention. Therefore, the process of the present invention is expected to be advantageously used for producing the styrenic polymer.

Abstract: In accordance with the present invention, there are provided ethylene copolymers composed of structural units (a) derived from ethylene and structural units (b) derived from .alpha.-olefin of 3.about.20 carbon atoms, said ethylene copolymers having?A! a density of 0.85.about.0.92 g/cm.sup.3,?B! an intrinsic viscosity ?.eta.! as measured in decalin at 135.degree. C. of 0.1.about.10 dl/g,?C! a ratio (Mw/Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) as measured by GPC of 1.2.about.4, and?D! a ratio (MFR.sub.10 /MFR.sub.2) of MFR.sub.10 under a load of 10 kg to MFR.sub.2 under a load of 2.16 kg at 190.degree. C. of 8.about.50, and being narrow in molecular weight distribution and excellent in flowability.

Abstract: There is disclosed a process for producing a styrenic polymer, especially, syndiotactic polystyrene, which comprises polymerizing a styrenic monomer by the use of (a) a transition metal compound, (b) a coordination complex compound comprising an anion in which a plurality of radicals are bonded to a metal and a cation or methylaluminoxane, (c) an alkylating agent (alkyl group-containing aluminum, magnesium or zinc compound) and (d) a reaction product between a straight-chain alkylaluminum having at least two carbon atoms and water (alkylaluminoxane). The above process is capable of simplifying the production process and producing high-performance styrenic polymer having a high degree of syndiotactic configuration in high catalytic activity without deteriorating the catalyst activity, increasing the amounts of residual metals in the objective polymer or leaving the decomposition products of the alkylaluminum therein, thereby curtailing the production cost of the objective polymer.