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: 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: 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 process for preparing a tetrakisfluorophenylborate which is useful as a catalyst component for the polymerization of olefins or as a raw material for synthesizing the same, efficiently at a high productivity per unit amount of a solvent and at a high yield. A mixed solvent of ether and an aliphatic hydrocarbon is used as a reaction solvent for preparing tetrakisphenylborate according to the following reaction formula,4M.sup.4 --C.sub.6 Y.sup.3.sub.5 +BCl.sub.3 .fwdarw.M.sup.4 B(C.sub.6 Y.sup.3.sub.5).sub.4wherein M.sup.4 is an alkali or alkaline earth metal, or represents R.sup.6.sub.2 Al, wherein R.sup.6 is an alkyl group, and Y.sup.3 is a hydrogen atom or a halogen atom.

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 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: 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: 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: There are disclosed a process for producing a styrene polymer having a high degree of syndiotactic configuration at a reduced cost and an enhanced efficiency, and a catalyst to be used therefor which comprises (A) a specific transition-metal compound, (B) a specific coordination complex compound and (C) a compound having an alkyl group. The catalyst according to the present invention is inexpensive compared with the conventional catalyst containing aluminoxane as the major ingredient, and exhibits a high activity in polymerizing a styrenic monomer into styrene polymer with a high degree of syndiotacticity as well as a high yield and conversion rate.

Abstract: A catalyst for producing styrene-based polymers, containing (A) a titanium compound, (B) a contact product of an organoaluminum compound and water, and (C) an organic polyhydroxy compound, or (A) a titanium compound and (B) a contact product of an organoaluminum compound, water and a organic polyhydroxy compound, and a process for producing styrene-based polymers by the use of the above catalyst.

Abstract: A catalyst for producing styrene-based polymers, containing (A) a titanium compound, (B) a contact product of an organoaluminum compound and water, and (C) an organic polyhydroxy compound, or (A) a titanium compound and (B) a contact product of an organoaluminum compound, water and a organic polyhydroxy compound, and a process for producing styrene-based polymers by the use of the above catalyst.

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.

Abstract: There are disclosed a catalyst which comprises a specific transition-metal compound (A) and a specific coordination complex compound (B) instead of aluminoxane, and a process for producing a styrene polymer at a reduced cost with improved efficiency by the use of the above catalyst.The catalyst according to the present invention is inexpensive compared with the conventional catalyst containing aluminoxane as the major ingredient, and exhibits a high activity in the polymerization of a styrenic monomer into styrene polymer with a high degree of syndiotacticity as well as a high yield and conversion rate.

Abstract: A catalyst for producing styrene-based polymers, containing (A) a titanium compound, (B) a contact product of an organoaluminum compound and water, and (C) an organic polyhydroxy compound, or (A) a titanium compound and (B) a contact product of an organoaluminum compound, water and a organic polyhydroxy compound, and a process for producing styrene-based polymers by the use of the above catalyst.

Abstract: There are disclosed a process for producing a styrene polymer having a high degree of syndiotactic configuration at a reduced cost and an enhanced efficiency, and a catalyst to be used therefore which comprises (A) a specific transition-metal compound, (B) a specific coordination complex compound and (C) a compound having an alkyl group.The catalyst according to the present invention is inexpensive compared with the conventional catalyst containing aluminoxane as the major ingredient, and exhibits a high activity in polymerizing a styrenic monomer into styrene polymer with a high degree of syndiotacticity as well as a high yield and conversion rate.

Abstract: The present invention provides a process for producing a homogeneous aluminoxane solution wherein an alkylaminoxane (A) obtained by reacting an organoaluminum compound with water and removing a solid residue by filtration is reacted with an organoaluminum compound (C) in the presence of an aromatic hydrocarbon solvent (B). According to the present invention, the gel-free homogeneous aluminoxane solution can be obtained and the catalytic activity thereof is not deteriorated during the storage.

Abstract: The present invention relates to a process for preparing aluminoxane which comprises reacting an organoaluminum compound and water in a solvent system containing solvent having a higher boiling point than that of the organoaluminum compound, or reacting an organoaluminum compound and water, and then adding a solvent system containing the solvent having a higher boiling point than that of the organoaluminum compound to the reaction mixture; and thereafter condensing the resulting reaction mixture under atmospheric pressure or reduced pressure.

Abstract: Disclosed is a process for drying aluminoxane, which comprises drying a viscous solution containing aluminoxane, while applying a shearing force sufficient to keep said viscous solution in polydispersive state, so as to make the solution to be a solid-state polydispersoid. Also disclosed is a process for producing a polymer which comprises polymerizing a polymerizable monomer, using the aluminoxane obtained by the process of the present invention.According to the process of the present invention, aluminoxane in uniform powder which is easy to treat can be efficiently obtained in an industrial scale, and polymers can be produced at high efficiency.

Abstract: A catalyst for producing styrene-based polymers having mainly syndiotactic configuration which comprises (A) a titanium compound and (B) a contact product of a methyl group-containing organoaluminum compound and water, wherein the contact product (B) has a high magnetic field component of not more than 50% in the methyl proton signal region due to an aluminum-methyl group (Al-CH.sub.3) bond as determined by the proton nuclear magnetic resonance absorption method.

Abstract: A method of preparing ethylene polymers which comprises polymerizing ethylene, or ethylene and one or more .alpha.-olefins other than ethylene in the presence of a composite catalyst which catalyst comprises:(A) a solid composition prepared by depositing one or more chromium compounds and one or more metal compounds other than said chromium compounds onto an inorganic oxide support material and then calcining the resulting solid; and(B) one or more organometallic compounds that are each independently represented by the following general formula:MR.sup.1 aR.sup.2 bR.sup.3 cwherein M is a metal of Group I, II or III of the periodic table and the R.sup.1, R.sup.2 and R.sup.3 moieties are each independently hydrogen, a hydrocarbon radical of C.sub.1 -C.sub.14, or an alkoxy group of C.sub.1 -C.sub.