Abstract: A process for producing an alpha-olefin polymer, which comprises polymerizing an alpha-olefin in the presence of a catalyst formed from (A) a transition metal compound comprising (A-1) a transition metal atom, (A-2) a hetero atom-containing ligand containing a heteroatom selected from oxygen, sulfur, nitrogen and phosphorus capable of forming a bond with the transition metal atom, and (A-3) a ligand having a conjugated .pi. electron through which the ligand can be bonded to the transition metal atom (A-1), and (B) an aluminoxane. The transition metal compound may be pre-treated with (C) an organometallic compound, or (D) a halogen-containing inorganic compound of an element of Group III, IV or V of the periodic table.

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

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

Abstract: The novel propylene elastomer according to the invention contains (1) units derived from propylene in amounts of 50 to 95% by mol and units derived from 1-butene in amounts of 5 to 50% by mol, and has (2) triad tacticity (mm fraction), determined by the .sup.13 C-NMR spectrum (hexachlorobutadiene solution, based on tetramethylsilane), of not less than 90%, (3) an intrinsic viscosity (in decalin at 135.degree. C.) of 0.1 to 12 dl/g, (4) a molecular weight distribution (Mw/Mn) of not more than 3 and (5) a randomness parameter B value of 1.0 to 1.5, preferably 1.0 to 1.3. In addition, the elastomer desirably has properties that (6) the elastomer has a melting point Tm of 60.degree. to 140.degree. C., and the melting point Tm and a 1-butene constituent unit content M (% by mol) in the elastomer satisfy the relation -2.6M+130.ltoreq.Tm.ltoreq.-2.3M+155, and (7) a crystallinity C of the elastomer measured by X-ray diffractometry and the 1-butene constituent unit content M (% by mol) satisfy the relation C.ltoreq.

Abstract: A process for the polymerization of olefinic hydrocarbons is carried out in the presence of a catalyst comprising a catalyst component derived from reacting a compound of the formula Me.sup.1 R.sup.1.sub.n X.sup.1.sub.4-n, a compound of the formula Me.sup.2 R.sup.2.sub.m X.sup.2.sub.z-m, an organocyclic compound having two or more conjugated double bonds and a carrier of inorganic or polymeric material, and a modified organoaluminum compound having Al--O--Al bonds, the resulting polyolefins having a relatively wide molecular weight distribution, a relatively narrow composition distribution and increased bulk density.

Abstract: There are disclosed a catalyst for producing an aromatic vinyl compound-based polymer composition which catalyst comprises (A) at least two different transition metal compounds each having one .pi.-ligand and (B) an ionic compound comprising a noncoordinate anion and a cation and/or an aluminoxane, and (C) a Lewis acid to be used as the case may be; and a process for producing an aromatic vinyl compound-based polymer composition having a high degree of syndiotactic configuration in its aromatic vinyl chains which process comprises polymerizing an (a) aromatic vinyl compound and (b) an olefinic compound and/or a diolefinic compound in the presence of the above catalyst.

Abstract: The novel transition metal compound of the invention is represented by the following formula (I): ##STR1## wherein M is a transition metal; R.sup.1 is a hydrocarbon group of 2 to 6 carbon atoms, R.sup.2 is an aryl group of 6 to 16 carbon atoms; X.sup.1 and X.sup.2 are each a halogen atom or the like; and Y is a divalent hydrocarbon group, a divalent silicon-containing group or the like. An olefin polymerization catalyst component of the present invention comprises the aforementioned transition metal compound. An olefin polymerization catalyst of the present invention comprises the aforementioned olefin polymerization catalyst component. The propylene homopolymer, the propylene copolymer and the propylene elastomer according to the present invention have such properties that the triad tacticity of propylene units chain is high, a proportion of the inversely units based on the 2,1-insertion of propylene monomer is in the specific range, and the intrinsic viscosity [.eta.

Abstract: A method for preparing an ethylene copolymer which comprises the step of copolymerizing ethylene with an aromatic vinyl compound in the presence of a catalyst comprising (A) a specific transition metal compound represented by the formula I ##STR1## and (B) a cocatalyst such as an aluminoxane.

Abstract: There is provided a process for the production of a cycloolefin copolymer which comprises copolymerizing an .alpha.-olefin having 2 or more carbon atoms and a specific cycloolefin in the presence of a specific metallocene type catalyst in a solvent mixture of a hydrocarbon solvent having a solubility parameter (value of .delta.) of 7.7 [(cal/cm.sup.3).sup.1/2 ] or more and a hydrocarbon solvent having a solubility parameter (value of .delta.) of 7.5 [(cal/cm.sup.3).sup.1/2 ] or less as a polymerization solvent. A cycloolefin copolymer having a high molecular weight can be produced in a high concentration by this process at a high yield.

Abstract: A process for producing an alpha-olefin polymer, which comprises polymerizing an alpha-olefin in the presence of a catalyst formed from(A) a solid catalyst component comprising an inorganic carrier and deposited thereon a compound of a transition metal of Group IVB of the periodic table treated with an organometallic compound, and(B) an aluminoxane.

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: A process for the polymerization of olefinic hydrocarbons is carried out in the presence of a catalyst comprising a catalyst component derived from reacting a compound of the formula Me.sup.1 R.sup.1.sub.n X.sup.1.sub.4-n, a compound of the formula Me.sup.2 R.sup.2.sub.m X.sup.2.sub.z-m, an organocyclic compound having two or more conjugated double bonds and a carrier of inorganic or polymeric material, and a modified organoaluminum compound having Al--O--Al bonds, the resulting polyolefins having a relatively wide molecular weight distribution, a relatively narrow composition distribution and increased bulk density.

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: 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: 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: A process for producing a polyolefin is here disclosed which comprises the step of polymerizing olefins in the presence of a catalyst comprising (A) a compound of a transition metal in the group IV of the Periodic Table, (B) an aluminoxane, (C) a compound having 2 or more aromatic rings in its molecule represented by the formulaAr.sup.1 --(YR.sub.n-2).sub.k --Ar.sup.2wherein the symbols are as defined in the specification, and if necessary, (D) an organic aluminum compound. In this process, the novel catalyst having a high polymerization activity is used, whereby the desired polyolefin can be efficiently produced.

Abstract: A process for the preparation of polyolefin which comprises polymerizing or copolymerizing olefin in the presence of a catalyst for olefin polymerization comprising (A) a metallocene compound of a transition metal selected from the Group IVB of the periodic table, and (B) an organoaluminum oxy-compound; wherein the organoaluminum oxy-compound (B) is added to the polymerization system in the form of a slurry in an aliphatic hydrocarbon or alicyclic hydrocarbon, and the polymerization is carried out in the presence of the aliphatic hydrocarbon diluent or an alicyclic hydrocarbon diluent having a boiling point below 100.degree. C.

Abstract: Amorphous propylene polymers are disclosed having the following characteristics:(a) intrinsic viscosity [.eta.]>1 d1/g;(b) %(r)-%(m)>0, wherein % (r) is the % of syndiotactic diads and %(m) is the % of isotactic diads;(c) less than 2% of the CH.sub.2 groups contained in sequences (CH.sub.2).sub.n, with n.gtoreq.2;(d) Bernoullianity index (B)=1.+-.0.2.These propylene polymers, which are in addition endowed with a narrow molecular weight distribution, can be obtained directly from the polymerization reaction of propylene as sole product and, therefore, do not require to be separated.

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: A solution process for the preparation of high molecular weight polymers of alpha-olefins selected from the group consisting of homopolymers of ethylene and copolymers of ethylene and C.sub.3 -C.sub.12 higher alpha-olefins is disclosed. Ethylene and/or mixtures of ethylene and C.sub.3 -C.sub.12 higher alpha-olefins are polymerized under non-isothermal conditions in a tubular reactor or in a system of reactors which operate under different conditions, in the presence of a catalytic amount of a titanium-containing coordination catalyst in an inert solvent at a temperature in excess of 105.degree. C. The improvement is characterized in that:(a) the catalyst is activated with a solution of a mixture of aluminum alkyl and alkoxy aluminum alkyl in inert solvent; and(b) the process is controlled by adjusting the ratio of aluminum alkyl to alkoxy aluminum alkyl in the mixture of (a). The aluminum alkyl is of the formula AlR.sub.n X.sub.3-n and the alkoxy aluminum alkyl is of the formula AlR'.sub.m OR".sub.

Abstract: A process for the preparation of ultrahigh molecular weight polyethylene having a high bulk density by polymerization of ethylene in the presence of a mixed catalyst, the catalyst comprising an organic aluminum compound and a titanium component prepared by reduction of a Ti(IV) compound and after-treatment of the reduction product thereof with an organic aluminum compound.

Abstract: The production of diene rubbers polymerized by means of Nd catalysts and having reduced cold flow and low intrinsic odor is effected by the polymerization of diolefines adiabatically at temperatures of -20.degree. to 150.degree. C. in the presence of inert organic solvents and in the presence of metallo-organic mixed catalysts based on neodymium carboxylate, by subsequently depressurizing the reaction mixture obtained in this manner by reducing the pressure, and by treating the reaction mixture thereafter with disulphur dichloride, sulphur dichloride and/or thionyl chloride.

Abstract: A process for the preparation of an ethylene/1-butene or ethylene/1-butene/diene elastomer by slurry polymerization of the monomers in a polymerization medium consisting mainly of an excess of the 1-butene maintained in liquid form, performed in the presence of a catalyst based on a metallocene compound of Ti, Zr or Hf. This process is exempt from occurrence of reactor fouling and enables the recovery of the polymer without the use of steam as a stripping agent.

Abstract: There is provided a process for producing a cyclic olefin copolymer by copolymerizing (A) ethylene and (B) a particular cyclic olefin in the presence of (C) a metallocene catalyst and (D) a small amount of an .alpha.-olefin having 3 to 20 carbon atoms. According to the said process, said copolymer can be produced at a high activity and its molecular weight can be controlled in a wide range. The copolymer produced by the said process has excellent properties inherent to the cyclic olefin copolymer.

Abstract: Catalyst support containing an .alpha.-olefin polymer which is in the form of particles of mean size from 5 to 350 .mu.m in which the pore volume generated by the pores of radius from 1,000 to 75,000 .ANG. is at least 0.2 cm.sup.3 /g.Catalyst usable for the polymerization of .alpha.-olefins, including a compound containing at least one transition metal belonging to groups IIIb, IVb, IVb and VIb of the Periodic Table, bound in or on this support.

Abstract: The invention relates to a novel process for producing a supported metallocene catalyst system useful for the polymerization and/or copolymerization of olefins, alpha-olefins, and/or diolefins which results in a catalyst product which during polymerization, produces minimal to no reactor fouling and polymer of controlled morphology. The invention is particularly useful for but not limited to polymerizing propylene or copolymerizing propylene with olefins having two or more carbon atoms. The novel support technique described herein results in a catalyst which will obtain polymer product having controlled, uniform particle size, narrow molecular weight distribution, high bulk density and depending upon the metallocene employed and monomers polymerized, stereoregularity.

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: A polymerization catalyst comprising a reaction product of an organic rare earth metal compound of the formula (I),Cp.sub.a Lx.sub.b M.sub.c D.sub.d (I)(wherein in the formula (I), Cp is a substituted or unsubstituted cyclopentadienyl group, indenyl group, fluorenyl group or their derivatives, or a multidentate coordination compound residue obtained by bonding these groups by way of hydrocarbon or silicon,L is a metal selected from the group consisting of elements having an atomic number of 39 and 57-71,X is a halogen atom,M is an alkaline metal or alkaline earth metal,D is an electron donor,a is 1-2,b is 1-2,c is 0-1, andd is 0-3) with a Grignard reagent of the formula (II),RMgX (II)wherein in the formula (II), R is a hydrocarbon group, and X is a halogen atom); a method for producing a polyolefin or an olefin block copolymer by using the above-mentioned catalyst; and an olefin block copolymer produced by the above-mentioned method.

Abstract: The present invention relates to a method for activating coordination catalysts suitable for the polymerization of alpha olefins using a alkoxy aluminum alkyl compound prepared by mixing an alcohol and an alkyl aluminum. The activator retains its activity and is easy to prepare simplifying the polymerization process.

Abstract: A process for preparing syndiotactic vinylidene aromatic polymers comprising contacting one or more vinylidene aromatic monomers with a catalyst comprising a Group 4 metal complex in the +3 oxidation state and a polyalkylaluminoxane cocatalyst.

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: A process for the production of EPM or EPDM comprising contacting ethylene, propylene, and, optionally, one or more dienes, in a fluidized bed, at a temperature at or above the sticking temperature of the product resin, under polymerization conditions, with(i) a prepolymer containing a transition metal catalyst precursor with the proviso that the prepolymer is not sticky at the process temperature;(ii) a hydrocarbyl aluminum and/or a hydrocarbyl aluminum halide cocatalyst,; and, optionally,(iii) a halocarbon promoter; and, optionally,(iv) an inert particulate material having a mean particle size in the range of about 0.01 to about 150 microns wherein the particulate material is either contained in the prepolymer or is independent of the prepolymer,wherein the amount of prepolymer or the combined amount of prepolymer and inert particulate material is sufficient to essentially prevent agglomeration of the fluidized bed and the product resin.

Abstract: A process for polymerizing ethylene at a high temperature under high pressure, which comprises contacting ethylene alone or along with an .alpha.-olefin at a temperature of 120.degree. C. or more at a pressure of 350 kg/cm.sup.2 or more with a catalyst consisting essentially of (A) a reaction product of (A1) a titanium compound having at least one titanium-nitrogen bond with (A2) an organometallic compound of an element of Groups I to III of the Periodic Table and (B) an organoaluminum compound. Said process enables the production of an ethylene polymer or copolymer having a narrow composition distribution and a high molecular weight and being excellent in weather resistance, color development, transparency, corrosiveness and mechanical properties.

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: In accordance with the present invention, there is provided catalyst systems and processes for preparing such catalyst systems comprising reacting a metallocene compound, a solid organoaluminoxy product, and an organometal compound. Further there is provided processes for the polymerization of olefins using the catalyst systems.

Abstract: In an improved process for producing elastomeric ethylene-propylene copolymers with a propylene content comprised within the range of from 22 to 38% by weight and a content of residual chlorine, coming from the co-catalyst, lower than 300 parts per million parts, the polymerization is carried out in suspension in the monomers in the liquid state, with vanadium triacetylacetonate and alkyl-Al compounds, and the obtained polymer is recovered without any washing steps.

Abstract: A catalyst system comprising:(a) a catalyst precursor consisting essentially of the reaction product of vanadium (acetylacetonate).sub.3 and a compound having the formula AlR.sub.(3-a) X.sub.a wherein each R is independently alkyl having 1 to 14 carbon atoms; each X is independently chlorine, bromine, or iodine; and a is 1 or 2; the atomic ratio of aluminum to vanadium in the precursor is 1:1 to 3:1; and the oxidation state of the vanadium in the reaction product is plus 2;(b) optionally, a support for said precursor; and(c) a halide substituted hydrocarbyl aluminum cocatalyst; and(d) optionally, a promoter, which is a chlorinated ester having at least 2 chlorine atoms; a saturated or unsaturated aliphatic halocarbon having at least 3 carbon atoms and at least 6 halogen atoms; or a haloalkyl substituted aromatic hydrocarbon wherein the haloalkyl substituent has at least 3 halogen atoms.

Abstract: A support containing methylalumoxane and derivatives thereof is described which is formed by an incipient impregnation technique. The most preferred support is silica. Incipient impregnation in accordance with the invention provides a supported alumoxane, methylalumoxane, which substantially eliminates the problem of fluid bed reactor fouling when methylalumoxane is introduced into the reactor during its operation. The process comprises providing methylaluminoxane in particulate form for use as a catalytic component in the fluidized bed gas phase polymerization process.In accordance with the invention, the process comprises providing methylalumoxane activated metallocene compound in particulate form as catalysts in fluid bed gas phase.

Abstract: The present invention relates to a solid catalyst composed of a specific solid catalyst component [A-1], the catalyst containing the solid catalyst and the olefin polymerization process using the solid catalyst, in which the solid catalyst component [A-1] comprises; (a-1) a particulate carrier composed of a specific oxide of a metal; (a-2) an organoaluminum oxy compound; and (a-3) a specific transition metal compound containing a specific ligand, wherein the organoaluminum oxy compound (a-2) and the transition metal compound (a-3) are supported on the particulate carrier (a-1).The catalysts are applicable to a suspension polymerization and a vapor phase polymerization, and capable of preparing spherical olefin polymers excellent in particle characteristics at high polymerization activity.

Abstract: A process for producing EP and EPDM polymers with a reduction in fouling is provided, which process comprises polyemrizing ethylene, an alpha-olefin and a nonconjugated diolefin (if utilized) in a polymerization medium comprising a hydrocarbon diluent at a temperature of from about -50.degree. C. to about 150.degree. C. in the presence of a catalyst system comprising (a) a vanadium compound, (b) diethyl aluminum chloride, ethyl aluminum sesquichloride or ethyl aluminum dichloride and (c) an organo aluminum compound of the formula R.sub.3 Al wherein R is an alkyl group having from 8 to 12 carbon atoms and, optionally, triethyl aluminum, the molar ratio of chloride in diethyl aluminum chloride to the total aluminum content in (b) and (c) being from about 0.7:1 to about 0.95:1, the molar ratio of the chloride in ethyl aluminum sesquichloride to the total aluminum content in (b) and (c) being from about 0.7:1 to about 1.

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 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: A process for producing high cis-1,4-polybutadienes using a catalyst system based on a rare earth compound that exhibits improved catalytic activity is provided which process comprises polymerizing 1,3-butadiene in a polymerization medium comprising a hydrocarbon solvent at a temperature of from about 0.degree. C. to about 120.degree. C. in the presence of a catalyst system which is a mixture of (1) a rare earth carboxylate selected from the group of neodymium carboxylates wherein the carboxylate has from 4 to 12 carbon atoms, (2) an alkyl aluminum chloride selected from the group of compounds represented by the formulae R.sup.2 AlCl.sub.2, R.sup.2.sub.3 Al.sub.2 Cl.sub.3 and R.sup.2.sub.2 AlCl wherein R.sup.2 is a hydrocarbon residue having from 8 to 12 carbon atoms and (3) an organo aluminum compound of the formula R.sup.3.sub.2 AlH wherein R.sup.

Abstract: The catalyst for olefin polymerization of the present invention contains R.sup.1.sub.k R.sup.2.sub.1 R.sup.3.sub.m M(SO.sub.3 R.sup.4) (M=Zr, Ti or Hf; R.sup.1-3 =a group having a cyclopentadienyl skeleton) as a catalyst component of a transition metal compound. According to the catalyst of the invention, an olefin polymer having excellent particle properties can be prepared with high polymerization activities, and further a copolymer having a narrow composition distribution can be prepared when two or more monomers are copolymerized. Of the above-mentioned transition metal compounds, a compound represented by the following formula is a novel compound unknown so far and shows excellent catalytic properties. ##STR1## (Cp=a group having a cyclopentadienyl skeleton, X=SO.sub.3 R, a halogen atom, R, OR, NR.sub.n, S(O).sub.q R, SiR.sub.3 or P(O).sub.q R.sub.3, n=1, 2 or 3; q=0, 1 or 2).

Abstract: The catalyst for olefin polymerization of the present invention contains R.sub.k.sup.1 R.sub.l.sup.2 R.sub.m.sup.3 M(SO.sub.3 R.sup.4) (M=Zr, Ti or Hf; R.sup.1-3 =a group having a cyclopentadienyl skeleton) as a catalyst component of a transition metal compound. According to the catalyst of the invention, an olefin polymer having excellent particle properties can be prepared with high polymerization activities, and further a copolymer having a narrow composition distribution can be prepared when two or more monomers are copolymerized. Of the above-mentioned transition metal compounds, a compound represented by the following formula is a novel compound unknown so far and shows excellent catalytic properties. ##STR1## (Cp=a group having a cyclopentadienyl skeleton, X=SO.sub.3 R, a halogen atom, R, OR, NR.sub.n, S(O).sub.q R, SiR.sub.3 or P (O).sub.q R.sub.

Abstract: The catalyst for olefin polymerization of the present invention contains R.sup.1.sub.k R.sup.2.sub.l R.sup.3.sub.m M(SO.sub.3 R.sup.4) (M=Zr, Ti or Hf; R.sup.1-3 =a group having a cyclopentadienyl skeleton) as a catalyst component of a transition metal compound. According to the catalyst of the invention, an olefin polymer having excellent particle properties can be prepared with high polymerization activities, and further a copolymer having a narrow composition distribution can be prepared when two or more monomers are copolymerized. Of the above-mentioned transition metal compounds, a compound represented by the following formula is a novel compound unknown so far and shows excellent catalytic properties. ##STR1## (Cp=a group having a cyclopentadienyl skeleton, X=SO.sub.3 R, a halogen atom, R, OR, NR.sub.n, S(O).sub.q R, SiR.sub.3 or P(O).sub.q R.sub.

Abstract: The method of forming a catalytic component for use in the polymerization of ethylene or a copolymer of ethylene and a C.sub.3 to C.sub.12 alpha olefin in a gas-phase comprising impregnating a porous metal oxide support with at least one titanium compound, magnesium compound, and chlorine compound, and prepolymerizing ethylene or a copolymer of ethylene and a C.sub.3 to C.sub.12 alpha olefin, a least partially in suspension, in the presence of said porous metal oxide support and at least one alkylaluminum compound until a degree of prepolymerization is reached which is suitable for the subsequent gas-phase of fluidized bed polymerization, and the method of polymerizing olefins utilizing the catalysts formed by the prepolymerization.

Abstract: A process for producing high cis-1,4-polybutadienes wherein there is reduced gel formation is provided which process comprises: polymerizing 1,3-butadiene in a polymerization medium comprising an inert hydrocarbon solvent and water at a temperature of from about -30.degree. C. to about 60.degree. C. in the presence of a catalyst system which is a mixture of (1) a substantially anhydrous divalent cobalt salt, (2) diethyl aluminum chloride or ethyl aluminum sesquichloride and (3) an organo aluminum compound of the formula R.sub.3 Al wherein R is an alkyl group having from 8 to 12 carbon atoms and, optionally triethylaluminum, the molar ratio of chloride in the diethyl aluminum chloride plus (3) being from about 0.7:1 to about 1 and the molar ratio of chloride in the ethyl aluminum sesquichloride plus (3) being from about 0.7:1 to about 1.

Abstract: A process for production of styrene polymers of high syndiotactic configuration is disclosed, comprising polymerizing styrene or styrene derivatives by the use of a catalyst comprising: (A) a titanium compound, e.g., at least one compound selected from those represented by the formulae: TiR.sup.1.sub.a R.sup.2.sub.b R.sup.3.sub.c X.sup.1.sub.4 -(a+b+c) and TiR.sup.1.sub.d R.sup.2.sub.e X.sup.1.sub.3-(d+e) (all the symbols are as defined in the appended claims); and (B) a contact product of an organoaluminum compound and a condensation agent, e.g., a product resulting from modification of trimethylaluminum with water. Because of such high syndiotactic configuration, the styrene polymers are greater in thermal resistance and solvent resistance than conventional atactic polystyrene.