Abstract: A process for effectively producing a cyclic olefin polymer and a cyclic olefin/alpha-olefin copolymer without opening the cyclic olefin, is disclosed. Further, a novel cyclic olefin/alpha-olefin copolymer prepared by the above-mentioned process, compositions and molded articles comprising the novel copolymer, are also disclosed. In the process for producing a cylcic olefin based polymer according to the present invention, homopolymerization of a cyclic olefin or copolymerization of a cyclic olefin and an alpha-olefin is effected in the presence of a catalyst comprising, as main ingredients, the following Compounds (A) and (B), and optionally Compound (C):(A) a transition metal compound;(B) a compound capable of forming an ionic complex when reacted with a transition metal compound; and(C) an organoaluminum compound.

Abstract: Disclosed is a catalyst component for the polymerization of olefins, which is a compound having the following structure: ##STR1## wherein R.sup.1 is a hydrocarbon radical having 1 to 10 carbon atoms or a halogen-containing hydrocarbon radical having 1 to 10 carbon atoms, and R.sup.2 s are each a hydrogen atom, a halogen atom, a siloxy group, a lower-alkyl-substituted siloxy group or a hydrocarbon radical having 1 to 10 carbon atoms, or which is a reaction product of the following sub-components (i) and (ii):sub-component (i) which is a compound having the formulaR.sup.1 --B--(OH).sub.2in which R.sup.1 is a hydrocarbon radical having 1 to 10 carbon atoms or a halogen-containing hydrocarbon radical having 1 to 10 carbon atoms; andsub-component (ii) which is an organoaluminum compound.

Abstract: Cycloolefin block copolymers, which in particular are suitable as phase promoters, are preferably obtained by copolymerization of polycyclic olefins, such as norbornene, with acyclic olefins, such as ethylene, by, at a molecular weight distribution M.sub.w /M.sub.n of the polymer block forming of less than 2, changing the reaction conditions one or more times in such a way that the monomer/comonomer ratio changes by at least 10% or a further polymerizable monomer is metered into the monomer or the monomers.

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, and R.sub.

Abstract: Disclosed is a catalyst having the general formula ##STR1## where Q is a ligand containing the ring ##STR2## R is hydrogen, N(R').sub.2, OR', or R', each R' is independently selected from alkyl from C.sub.1 to C.sub.10, aryl from C.sub.6 to C.sub.15, alkaryl C.sub.7 to C.sub.15, and aralkyl from C.sub.7 to C.sub.15, each X is independently selected from hydrogen, halogen, alkoxy from C.sub.1 to C.sub.10.sub., dialkylamino from C.sub.1 to C.sub.10, methyl, ##STR3## each R.sub.1 is independently selected from halogen, alkoxy from C.sub.1 to C.sub.10, and R', L is ##STR4## Q, or X, where L can be bridged to Q, B is an optional base, "n" is 0 to 5, and M is titanium, zirconium, or hafnium.

Abstract: Cycloolefin/alpha-olefin copolymers in a molar ratio from 5/95 to 95/5, optionally including long linear alpha-olefin, branched alpha-olefins and/or polyenes as additional comonomers, are prepared using a cyclopentadienyl metallocene catalyst system based on a transition metal compound from Group 4 of the Periodic Table of Elements. The copolymers have a high molecular weight, a narrow molecular weight distribution and a substantially uniform, random comonomer distribution.

Abstract: Process for the preparation of crystalline vinylaromatic polymers with a predominantly syndiotactic structure which comprises polymerizing the vinylaromatic monomers in the presence of a catalytic system consisting essentially of:a) a complex of titanium having the formula (I):Ti(OCONRR').sub.n (I)wherein R and R', the same or different, represent a C.sub.1 -C.sub.12 aliphatic radical or C.sub.6 -C.sub.12 aromatic radical whereas n is an integer equal to 3 or 4;b) a cocatalyst selected from aluminoxane and a compound of boron having formula (II):BX.sub.1 X.sub.2 X.sub.3 (II)wherein X.sub.1, X.sub.2 and X.sub.3, the same or different, represent a C.sub.1 -C.sub.20 perfluorinated hydrocarbon radical.

Abstract: This invention is a solution process for the preparation of high molecular weight ethylene-.alpha.-olefin-diolefin copolymers comprising contacting ethylene, one or more .alpha.-olefin monomer, and optionally one or more diene monomer, with a catalyst system at a polymerization temperature at or above about 80.degree. C., ethylene, one or more .alpha.-olefin monomer, and optionally one or more diene monomer, with a catalyst system comprising an unbridged Group 4 metal compound having a bulky monocyclopentadienyl ligand, a uninegative bulky Group 15 ligand and two uninegative, activation reactive ligands and a catalyst activator compound. The process can be advantageously practiced a reaction temperature of at least 80.degree. C., most preferably above 100.degree. C., to achieve high number average molecular weight polymer having high .alpha.-olefin monomer and diene monomer contents with high diene conversion rates.

Abstract: There is disclosed a process for producing a syndiotactic polystyrene (SPS) which comprises polymerizing a styrenic monomer having a content of indene-based compounds of at most 50 ppm by bringing a polymerization catalyst into contact with the above styrenic monomer, which catalyst preferably comprises an (A) transition metal compound (e.g. Ti compound) and (B) an (a) compound capable of reacting with the above transition metal compound (component (A)) to form an ionic complex (e.g. DMAB) or a (b) oxygen atom-containing compound (e.g. MAO), and optionally a (C) alkyl group-containing metallic compound (e.g. TIBA). By virtue of using the above styrenic monomer, the process enables to minimize the amount of the residual metals in the resultant styrenic polymer without deterioration of the catalytic activity, simplify the process and thereby curtail the production cost of SPS.

Abstract: A copolymerization process suitable for the preparation of high crystalline melting point cyclic olefin copolymers comprising contacting ethylene, and at least one cyclic olefin with an active polymerization catalyst comprising a Group 4 transition metal compound containing an asymmetrically substituted monocyclopentadienyl ancillary ligand, a bulky substituent-containing heteroatom ligand, the monocyclopentadienyl and heteroatom ligands being covalently bridged is disclosed. Ethylene/norbornene copolymers prepared in accordance with the invention exhibited crystalline melting points of about 250.degree. C., and were prepared at high catalyst activity levels with feed ratios less than 6:1 of norbornene to ethylene.

Abstract: Olefins are polymerized by the use of catalysts comprising biscyclopentadienyl, Group 4 transition metal complexes formed with conjugated dienes wherein the diene is bound to the transition metal either in the form of a .sigma.-complex or a .pi.-complex in combination with activating cocatalysts.

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

Abstract: This invention is for a catalyst system for polymerization of olefins using an ionic metallocene catalyst with aluminum alkyl. The metallocene catalyst is an ion pair formed from a neutral metallocene compound and an ionizing compound. The invention can be used in any method of producing ionic metallocene catalysts. Use of aluminum alkyl with an ionic metallocene catalyst eliminates the need for using methylaluminoxane (MAO). Catalysts produced by the method of this invention have high activity. The invention reduces catalyst poisons which cause low activity, no activity or uncontrolled polymerizations. Polymerization using this catalyst system are reproducible and controllable.

Abstract: Disclosed is an ethylene-.alpha.-olefin-nonconjugated polyene random copolymer which is a random copolymer of (a) ethylene, (b) an .alpha.-olefin of 3 or more carbon atoms and (c) a nonconjugated polyene, and has such properties that (i) the copolymer contains (a) units derived from ethylene and (b) units derived from the .alpha.-olefin of 3 or more carbon atoms in a molar ratio of 40/60 to 95/5 ((a)/(b)), (ii) the iodine value is in the range of 1 to 50, (iii) the intrinsic viscosity (.eta.), as measured in decahydronaphthalene at 135.degree. C., is in the range of 0.1 to 8.0 dl/g, and (iv) the ratio g.eta.* of the intrinsic viscosity (.eta.) of the copolymer defined above to the intrinsic viscosity (.eta.).sub.blank of a linear ethylene-propylene copolymer having the same weight-average molecular weight as the ethylene-.alpha.-olefin-nonconjugated polyene random copolymer and having an ethylene content of 70% by mol, (.eta.)/(.eta.).sub.blank, is in the range of 0.2 to 0.

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, a (b) coordination complex compound comprising an anion in which a plurality of racicals are bonded to a metal and a cation or a Lewis acid, a (c) alkylating agent (alkyl group-containing aluminum, magnesium or zinc compound) and a (d) 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: There are disclosed a transition metal compound of the general formula RMX.sub.a-1 L.sub.b (R is as a .pi. ligand, a fused polycyclic cyclopentadienyl group in which at least one of many-membered rings to which cyclopentadienyl groups are fusedly bonded is a saturated ring, M is a transition metal, X is a .sigma. ligand, L is a Lewis base, a is the valency of M, and b is 0, 1 or 2); a polymerization catalyst for styrene, etc. comprising the above transition metal, preferably further comprising an oxygen atom containing compound ionic compound or organoboron compound and optionally a Lewis base; and a process for producing a polymer of a compound containing an ethylenically unsaturated double bond or an acetylenic polymer, especially a syndiotactic polystyrene by using the above polymerization catalyst. The catalyst is particularly effectivive for producing highly syndiotactic polystyrene minimized in residual metals amounts at a low cost in enhanced efficiency.

Abstract: A polymer having a repeating unit of ##STR1## and a method for preparing it through Zr-catalyzed polymerization of methylenecyclopropane is disclosed.

Abstract: Catalyst and process for the stereospecific propagation of a polymer chain derived from an ethylenically unsaturated monomer which contains 3 or more carbon atoms or is substituted vinyl compound. The catalysts comprise stereorigid metallocenes in which a structural bridge is not required for stereorigidity. The ring structures of the metallocene catalyst are substituted cyclopentadienyl rings. The substituent groups on the cyclopentadienyi rings impart stereorigidity to the catalyst by virtue of a sterically hindered relationship between the rings sufficient to prevent rotation of the rings. The catalyst is contacted with a C.sub.3 + alpha olefin or other ethylenically unsaturated compound in a polymerization reaction zone and maintained in contact with the catalyst in the reaction zone under polymerization conditions to produce a stereospecific polymer.

Abstract: Immobilized Lewis Acid catalyst comprising polymer having at least one Lewis Acid immobilized within the structure therein, said polymer having monomer units represented by the structural formula:--[A].sub.a --[B].sub.b --[C].sub.c --whereina represents about 1 to about 99 mole %b represents about 0 to about 50 mole %c represents about 1 to about 99 mole %a+b+c is preferably about 100%; ##STR1## C is selected from the group consisting of: ##STR2## (III) combinations thereof, wherein D is OH, halide, OR.sup.4, NH.sub.2, NHR.sup.3, OM', or OM";E is the residue of the reaction of at least one Lewis Acid with the D substituent of monomer unit B;R.sup.1 represents proton, C.sub.1 -C.sub.24 alkyl group, or C.sub.3 -C.sub.24 cycloalkyl;R.sup.2 represents C.sub.1 -C.sub.24 alkylene group, C.sub.3 -C.sub.24 cycloalkylene, C.sub.6 -C.sub.18 arylene, or C.sub.7 -C.sub.30 alkylarylene;R.sup.3 represents C.sub.1 -C.sub.24 alkyl, C.sub.3 -C.sub.24 cycloalkyl, C.sub.1 -C.sub.24 aryl, or C.sub.7 -C.sub.30 alkylaryl;R.sup.

Abstract: A process for polymerizing olefins, diolefins and/or acetylenically unsaturated monomers using novel catalyst compositions comprising titanium or zirconium complexes containing one and only one cyclic delocalized, anionic, .pi.-bonded group wherein the metal is in the +2 formal oxidation state and having a bridged ligand structure, also referred to as constrained geometry complexes, and an activating cocatalyst.

Abstract: There are disclosed a catalyst which comprises (A) a titanium compound having one .pi. electron-based ligand (e.g. pentamethylcyclopentadienyl group) or two same .pi. electron-based lignads and (B) an ionic compound comprising a non-coordinate anion and a cation of an element typifying the group 4 elements of the Periodic Table (e.g. triphenylcarbonium tetra(pentafluorophenyl)borate; a catalyst comprising (C) an alkylating agent (e.g. triisobutylaluminum) in addition to the components (A) and (B); and a process for producing a styrenic polymer by the use of any of the aforesaid catalysts. By using the aforementioned catalyst and process, a highly syndiotactic styrenic polymer can be efficiently produced.

Abstract: A polyolefin having superior particle properties such as an extremely high bulk density, a large average particle diameter and a narrow particle size distribution, and having a narrow molecular weight distribution, is obtained in high yield, by polymerizing an olefin, using a catalyst comprising a solid catalyst component and an organometallic compound, the solid catalyst component being obtained by reacting a) a silicon oxide and/or an aluminum oxide, the reaction product of an organomagnesium compound and a compound of the general formula Me(OR).sub.n X.sub.Z-n, and a titanium compound, in the presence of ROH, and further reacting the resulting reaction product with a compound of the general formula AlR.sub.q X.sub.3-q.

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: This invention is for a catalyst system for polymerization of olefins using an ionic metallocene catalyst with aluminum alkyl. The metallocene catalyst is an ion pair formed from a neutral metallocene compound and an ionizing compound. The invention can be used in any method of producing ionic metallocene catalyst. Use of aluminum alkyl with an ionic metallocene catalyst eliminates the need for using methylaluminoxane (MAO). Catalysts produced by the method of this invention have high activity. The invention reduces catalyst poisons which cause low activity, no activity or uncontrolled polymerizations. Polymerizations using this catalyst system are reproducible and controllable.

Abstract: There are disclosed a catalyst for producing an aromatic vinyl compound polymer which catalyst comprises a contact product between an (A) trivalent titanium compound and a (B) compound represented by the general formula (II) or (III)R.sup.1.sub.k M.sup.1 L.sup.2.sub.m (II)R.sup.1.sub.k M.sup.1 X.sup.2.sub.l L.sup.2.sub.m (III)a (C) an ionic compound comprising a noncoordinate anion and a cation, an aluminoxane or an organoboron compound; and optionally a (D) Lewis acid, and a process for producing an aromatic vinyl compound polymer having a high degree of syndiotactic configuration which process comprises polymerizing (a) an aromatic vinyl compound or (b) an aromatic vinyl compound together with an olefin or a diolefin in the presence of the above catalyst.

Abstract: This invention relates to non-Group 4 transition metal compositions useful as olefin polymerization catalysts, wherein the transition metal is in a high oxidation state. The invention further relates to design of new ligand systems and methods of preparing and using the same. Compositions useful as catalyst precursors are neutral transition metal complexes comprising the unique ligand systems of the invention. The inventive compositions may be activated to a catalytic state by ion-exchange reagents or by Lewis acids.

Abstract: The subject invention relates to a technique for synthesizing rubbery non-tapered, random, copolymers of 1,3-butadiene and isoprene. These rubbery copolymers exhibit an excellent combination of properties for utilization in tire sidewall rubber compounds for truck tires. By utilizing these isoprene-butadiene rubbers in tire sidewalls, tires having improved cut growth resistance can be built without sacrificing rolling resistance. Such rubbers can also be employed in tire tread compounds to improve tread wear characteristics and decrease rolling resistance without sacrificing traction characteristics.

Abstract: A material of a cycloolefin copolymer has a structure of alternating cycloolefin sequences, and has crystallinity in a temperature range from 210.degree. to 320.degree. C. The cycloolefin is prepared by polymerization of at least one polycyclic olefin, monocyclic and/or acyclic olefin with an open-chain olefin using a catalyst of a metallocene and an aluminoxane.

Abstract: A catalyst component for use in the polymerization of .alpha.-olefins, comprising a compound represented by the following general formula [I]: ##STR1## wherein R.sup.1 s represent a hydrogen atom, a C.sub.1-6 hydrocarbon group or a C.sub.1-12 hydrocarbon group containing silicon; each of R.sup.2 and R.sup.3 independently represents a divalent group selected from the group consisting of a hydrocarbon group having 3 to 30 carbon atoms and a silicon-containing hydrocarbon group having 1 to 30 carbon atoms and 1 to 6 silicon atoms, provided that at least one of R.sup.2 and R.sup.3 is said silicon-containing hydrocarbon group; Q represents a C.sub.1-20 divalent hydrocarbon group, a silylene group, a silylene group with a C.sub.1-20 hydrocarbon group, a germylene group, or a germylene group with a C.sub.1-20 hydrocarbon group; X and Y represent H, a halogen, a C.sub.1-20 hydrocarbon group, or a C.sub.

Abstract: A catalyst system comprising a transition metal-containing polymerization catalyst and a solid organoaluminoxy product produced by contacting a solution of an organoaluminoxane with an organic borane compound which is free of acidic hydrogen. The use of the catalyst system for the polymerization of olefins is also included.

Abstract: Novel titanium or zirconium complexes containing one and only one cyclic delocalized, anionic, .pi.-bonded group wherein the metal is in the +2 formal oxidation state and having a bridged ligand structure, also referred to as constrained geometry complexes; catalytic derivatives of such complexes; methods of preparation; and the use thereof as catalysts for polymerizing olefins, diolefins and/or acetylenically unsaturated monomers.

Abstract: There are disclosed a catalyst which comprises (A) a titanium compound having one .pi. electron-based ligand (e.g. pentamethylcyclopentadienyl group) or two same .pi. electron-based lignads and (B) an ionic compound comprising a non-coordinate anion and a cation of an element typifying the group 4 elements of the Periodic Table (e.g. triphenylcarbonium tetra(pentafluorophenyl)borate; a catalyst comprising (C) an alkylating agent (e.g. triisobutylaluminum) in addition to the components (A) and (B); and a process for producing a styrenic polymer by the use of any of the aforesaid catalysts. By using the aforementioned catalyst and process, a highly syndiotactic styrenic polymer can be efficiently produced.

Abstract: A polymerization catalyst comprising a polycation complex (A) represented by the following Formula, [(CUHC).sub.n MX.sub.m ].sup.j+ .multidot.([Y].sup.-)j; [(CUHC): a cyclic unsaturated hydrocarbon group], more particularly, a polymerization catalyst comprising the reaction product of a transition metal compound and an ionic compound (b) capable of forming an ionic complex when reacted with a transition metal compound, and the above-mentioned compound (b), is disclosed.

Abstract: A catalyst system and process for the polymerization of cyclic olefins, such as dicyclopentadiene, are disclosed. The catalyst system contains a transition metal hydrotrispyrazolylborate complex having the formula:Tp--M--L.sub.3wherein Tp is a hydrotrispyrazolylborate ligand, M is tungsten or molybdenum, and L is independently a ligand selected from the group consisting of oxo, phenoxy, alkoxy, and halides, provided that at least one L is a halide, and a co-catalyst.

Abstract: Catalyst systems for the polymerization of C.sub.2 -C.sub.10 -alkenes contain, as active components, a metallocene complex of a metal of subgroup IV or V of the Periodic Table, an oligomeric alumina compound and a cyclic boron compound of the general formula IV ##STR1## where R.sup.18 to R.sup.20 are each C.sub.1 -C.sub.10 -alkyl which may be monosubstituted to trisubstituted by halogen, C.sub.6 -C.sub.15 -aryl or C.sub.1 -C.sub.10 -alkoxy,C.sub.4 -C.sub.7 -cycloalkyl which may be monosubstituted to trisubstituted by halogen, C.sub.1 -C.sub.10 -alkyl or C.sub.1 -C.sub.10 -alkoxy,C.sub.1 -C.sub.10 -alkoxy which may be monosubstituted to trisubstituted by halogen, C.sub.1 -C.sub.10 -alkyl or C.sub.6 -C.sub.15 -aryl, or C.sub.6 -C.sub.15 -aryl which may be monosubstituted to pentasubstituted by halogen, C.sub.1 -C.sub.10 -alkyl or C.sub.1 -C.sub.10 -alkoxy.

Abstract: A process for preparing syndiotactic vinylidene aromatic polymers comprising contacting one or more vinylidene aromatic monomers with a catalyst comprising a cationic Group 4 metal complex wherein the metal is in the +3 oxidation state formed from the corresponding metal hydrocarbyloxy containing complex in the presence of a hydrocarbylation agent.

Abstract: Novel chromium-containing compounds are prepared by forming a mixture of a chromium salt, a metal amide, and an ether. These novel chromium-containing, or chromium pyrrolide, compounds, with a metal alkyl and an unsaturated hydrocarbon, can be used as a cocatalyst system in the presence of an olefin polymerization catalyst system to produce a comonomer in-situ. The resultant polymer, although produced from predominately one monomer, has characteristics of a copolymer.

Abstract: Cis-1,4-polybutadiene can be synthesized by polymerizing 1,3-butadiene monomer with a three component nickel catalyst system containing (a) an organonickel compound, (b) an organoaluminum compound, and (c) a fluorine containing compound. However, the molecular weight of the cis-1,4-polybutadiene prepared is typically too high to be utilized as a non-oil extended rubber. This invention is based upon the discovery that para-styrenated diphenylamine acts to reduce the molecular weight and to improve the processability of cis-1,4-polybutadiene prepared with such nickel based catalyst systems. The use of para-styrenated diphenylamine as a modifier in such polymerizations does not change the microstructure of the cis-1,4-polybutadiene produced.

Abstract: There is disclosed a process for producing a styrenic polymer having a syndiotactic configuration which comprises polymerizing a styrenic monomer containing hydrogen dissolved therein at a hydrogen partial pressure of at most 1 kg/cm.sup.2 G by the use of a polymerization catalyst comprising an (a) transition metal compound and a (b) coordination complex compound composed of a cation and an anion in which a plurality of radicals are bonded to a metal, or an aluminoxane and, when necessary, a (c) alkylating agent. The above process is capable of modifying the molecular weight of the objective SPS, lowering its molecular weight without expanding the molecular weight distribution, and decreasing the required quantity of the catalyst and the residual quantities of metals in the resultant SPS, whereby the production cost of the objective SPS is considerably curtailed.

Abstract: A one-pot method of preparing sulfonic acid-terminated polyisobutylene by sulfonation with acetyl sulfate of living polyisobutylene in a single step. The method permits preparation of sulfonated telechelic polyisobutylenes (STPs) by "inifer" initiated carbocationic polymerization of isobutylene with Lewis acid to form a polymer, followed by the addition in the same reaction vessel of acetyl sulfate at the polymerization temperature or the decomposition temperature of the complex.

Abstract: A novel transition metal compound represented by the formula ##STR1## (wherein each of A.sup.1, A.sup.2, A.sup.3 and A.sup.4 is a cyclopentadienyl group, an indenyl group, a fluorenyl group or their derivative; A.sup.5 is a hydrocarbondiylidene group having 4 to 30 carbon atoms; a pair of A.sup.1 and A.sup.2 as well as a pair of A.sup.3 and A.sup.4 is respectively bonded to the identical carbon atom in A.sup.5 to form a crosslinking structure; each of R.sup.1 and R.sup.2 is a halogen atom, a hydrogen atom, an alkyl group or a silicon-containing alkyl group having 1 to 10 carbon atoms, an aryl group, an alkylaryl group, an arylalkyl group or a halogenated aryl group having 6 to 20 carbon atoms; R.sup.1 and R.sup.2 may be identical or different; each of M.sup.1 and M.sup.2 is titanium, zirconium or hafnium; and M.sup.1 and M.sup.2 may be mutually identical or different), and a method for polymerizing an olefin in the presence of this compound and a co-catalyst.

Abstract: Solution and RIM polymerization of cycloolefins containing at least one norbornene moiety is carried out in the presence of a methathesis catalyst system and an activator, particularly a chlorosilane activator, to obtain faster reaction with higher conversions at lower mold temperatures. The methathesis catalyst system includes an organoammonium molybdate or tungstate catalyst and an alkylaluminum or an alkylaluminum halide cocatalyst. The chlorosilane activator is used at a level of 0.05 to 10 millimoles per mole of the cycloolefin monomers. The polymers of cycloolefins can be impact modified and/or flame-retarded.

Abstract: A process for preparing syndiotactic vinylidene aromatic polymers comprising contacting one or more vinylidene aromatic monomers with tri n-propyl aluminum chain transfer agent under Ziegler-Natta polymerization conditions.

Abstract: Polymers of polycyclic olefins such as, for example, norbornene or tetracyclododecene, or copolymers of polycyclic olefins with cycloolefins and/or 1-olefins with a very narrow molecular weight distribution are obtained without ring opening by a polymerization in which a catalyst which is composed of an aluminoxane and of a stereorigid, chiral metallocene compound of an element of groups IVb to VIb is used, and in which the reaction is stopped at a time when the molecular weight distribution Mw/Mn of the polymer formed is <2.

Abstract: In the case of Ziegler catalysts based on a metallocene as the transition metal component and an aluminoxane as the activator, preactivation of the metallocene with the aluminoxane results in a considerable increase in the activity of the catalyst system. Furthermore, 1-olefin polymers of a high degree of isotacticity and having compact, spherical particles, a very narrow particle size distribution and a high bulk density are obtained by means of a catalyst system of this type.

Abstract: There is provided a process for the preparation of a high cis-1,4-polybutadiene with a reduced microgel content wherein a novel catalyst system consisting of (1) a nickel salt of a carboxylic acid, (2) a mixture of triethyl aluminum and an organoaluminum compound having the formula R.sub.3 Al, said mixture having an average composition Et.sub.3-x R.sub.x Al wherein Et is an ethyl group, x is a numeral from 0.1 to 2.9 and R is an alkyl group having 8 to 12 carbon atoms, and (3) a boron trifluoride etherate is used to polymerize 1,3-butadiene in an inert hydrocarbon.

Abstract: In accordance with the present invention there is provided a new solid aluminoxy composition prepared by reacting aluminoxane with a boroxine. Still further there is provided olefin polymerization catalyst systems incorporating the inventive solid aluminoxy composition. Still further, there is provided processes of polymerization using the inventive solid aluminoxy composition.

Abstract: A process for the production of a homogeneous polyethylene comprising contacting ethylene, one or more alpha-olefins, and one or more unconjugated dienes, under polymerization conditions, with a catalyst system comprising:(A ) a modified supported vanadium based catalyst precursor;(B) an alkylaluminmn halide cocatalyst; and(C) a promoter consisting of an unsaturated aliphatic halocarbon or a haloalkyl substituted aromatic hydrocarbonwith the proviso that sufficient unconjugated diene is present to provide in the homogeneous polyethylene about 0.01 to less than about one percent by weight diene.

Abstract: An olefin metathesis catalyst system and process for the metathesis polymerization of cyclic olefins, such as dicyclopentadiene, are disclosed. The catalyst system comprises the reaction product of:(a) an imido transition metal halide complex of formula: ##STR1## wherein Ar is C.sub.6-20 aryl, preferably phenyl; M is a transition metal selected from the second and third rows of Groups 5, 6, 7 and 8 of the Periodic Table (IUPAC 1989 convention) and including for example niobium, tantalum, molybdenum, tungsten, rhenium, ruthenium or osmium, preferably tungsten or molybdenum; R is independently halide, C.sub.1-20 alkyl, C.sub.1-12 alkoxy, C.sub.1-12 haloalkyl, C.sub.6-20 aryl, C.sub.6-20 aryloxy, cyano or combinations thereof; L is independently a complexing ligand selected from carbonyl, C.sub.1-12 alkoxy, C.sub.1-12 haloalkoxy, C.sub.1-12 alkyl ethers, including mono-, di- and higher ethers, C.sub.12 alkylnitriles, C.sub.5-20 pyridines, C.sub.

Abstract: There are disclosed a catalyst well suited for producing a styrenic polymer having a high degree of syndiotactic configuration which comprises a transition-metal compound such as pentamethylcyclopentadienyltrimethyltitanium and a coordination complex compound comprising an anion in which a plurality of radicals are bonded to a metal and a quaternary ammonium salt, the compound being exemplified by orthocyano-N-methylpyridinium tetra(pentafluorophenyl)borate, or comprises an alkylating agent such as triisobutylaluminum in addition to the above two compounds; and a process for producing a styrenic polymer having a high degree of syndiotactic configuration by polymerizing a styrenic monomer using the aforementioned catalyst. Consequently, a styrenic polymer having a high degree of syndiotactic configuration can be produced effectively without the use of an expensive aluminoxane required in a large amount if used.