Abstract: A process for producing a modified conjugated diene polymer includes subjecting an active terminal of a conjugated diene polymer having a vinyl content of less than 10% and a cis-1,4 bond content of 75% or more to a modification reaction with an alkoxysilane compound, and subjecting the alkoxysilane compound (residue) to a condensation reaction in an aqueous solution at a pH of 9 to 14 and a temperature of 85 to 180° C. in the presence of a condensation accelerator including a compound containing titanium. The modified conjugated diene polymer exhibits low heat build-up and increased reinforcing properties when used for a rubber composition, and exhibits excellent wear resistance, mechanical characteristics, and processability.

Abstract: The method for producing a modified conjugated diene based (co)polymer, according to the present invention comprises a step of reacting a conjugated diene based (co)polymer with a metal halide compound to obtain a modified conjugated diene based (co)polymer, the conjugated diene based (co)polymer having a weight-average molecular weight of 150,000 to 2,000,000 and being obtained by bonding, to a polymer having at least a conjugated diene unit, an alkoxysilyl group and an optionally protected primary amino group. The method can satisfactorily produce a conjugated diene based (co)polymer which has a high Mooney viscosity, excellent shape stability and good processability.

Abstract: A conjugated diolefin copolymer rubber is produced by copolymerization of a conjugated diolefin and an aromatic vinyl compound and has a primary amino group and an alkoxysilyl group bonded to the copolymer chain. The conjugated diolefin copolymer rubber contains the aromatic vinyl compound in an amount of 5 to 60 wt %. The aromatic vinyl compound is densely distributed in one terminal of the copolymer chain, and is scarcely distributed in the other terminal. The conjugated diolefin copolymer rubber has a temperature difference (?Tg) of 25° C. or more. The conjugated diolefin copolymer rubber has low hysteresis loss properties as well as improved abrasion resistance, rupture characteristics, and road grip characteristics without impairing wet skid characteristics. A method for producing the conjugated diolefin copolymer rubber is also disclosed.

Abstract: The method for producing a modified conjugated diene based (co)polymer, according to the present invention comprises (a) obtaining a primarily modified polymer by carrying out a primary modification reaction wherein at least one member selected from the group consisting of an alkoxysilane compound and a silanol compound is introduced into the active alkali metal terminal of a conjugated diene based (co)polymer having an active alkali metal terminal, and (b) obtaining a secondarily modified polymer (a modified conjugated diene based (co)polymer) by subjecting the above-obtained primarily modified polymer to reactions comprising (b1) and (b2). (b1): a reaction with a condensation accelerator comprising a metal element. (b2): a reaction with at least one member selected from the group consisting of inorganic acids and metal halides.

Abstract: A method for producing a modified conjugated diene polymer includes a step (A) carrying out a primary modification reaction that reacts a heterocumulene compound having two or more specific functional groups with a conjugated diene polymer having a vinyl content of below 10% and a cis-1,4-bond content of 75% or more and possessing an active end to obtain a primary-modified conjugated diene polymer, and a step (B) carrying out a secondary modification reaction that reacts an active hydrogen-containing compound that includes one or more functional groups selected from the group consisting of an amino group, an imino group, a mercapto group, and a hydroxyl group with the primary-modified conjugated diene polymer to obtain a secondary-modified conjugated diene polymer. The method can produce a modified conjugated diene polymer that exhibits low heat build-up (low fuel consumption) and excellent wear resistance.

Abstract: A process for producing a modified polymer which increases low heat buildup and reinforcing capability of a rubber composition and which has excellent abrasion resistance, mechanical characteristics, and processability; a modified polymer obtained by the process; and a rubber composition using the modified polymer are provided. The process comprises a step of carrying out a modification reaction on the active end of a conjugated diene polymer having a vinyl content of below 10%, a cis-1,4 bond content of 75% or higher, and an active end, using an alkoxysilane compound, and a step of carrying out a condensation reaction in the presence of a condensation accelerator comprising a compound of an element belonging to at least one of the groups 4A (excluding Ti), 2B, 3B, and 5B of the periodic table.

Abstract: A method for producing a polymer for oil-resistant rubber, which comprises adding, to an aqueous dispersion of an unsaturated nitrile-conjugated diene copolymer (component A), a monomer composition (component B) containing at least one kind of monomer selected from the group consisting of a nitrile group-containing monomer (component B-1), a (meth)acrylic acid ester monomer (component B-2) and an aromatic vinyl compound monomer (component B-3), and conducting a polymerization reaction in a state that the ratio of the conjugated diene monomer present in the system, to the total monomers present in the system is controlled at 10 mol % or less.

Abstract: A radiation sensitive resin composition comprising (A) a colorant, (B) an alkali-soluble resin, (C) a polyfunctional monomer and (D) a radiation sensitive radical generator, wherein the alkali-soluble resin (B) is a resin having a group containing a dithiocarbonyl bond at least one terminal of its polymer chain. A color filter which is free from burning can be manufactured from this composition at a high yield.

Abstract: A rubber composition includes (i) an ?,?-unsaturated nitrile conjugated diene rubber containing structural units derived from a conjugated diene in an amount of 30 to 60 mass % with respect to the total structural units, (ii) an ethylene-?-olefin-nonconjugated diene copolymer rubber having a limiting viscosity of 3.3 dl/g or more measured at 135° C. in a decalin solvent, and (iii) a crosslinking agent. The rubber composition can produce a crosslinked rubber and a molded article exhibiting excellent oil resistance and heat resistance in a well-balanced manner.

Abstract: A process for simply and inexpensively producing a conjugated diene polymer with a narrow molecular weight distribution and a high cis-bond content at a low cost is provided. The process comprises a polymerization step, wherein a conjugated diene polymer having a cis-1,4-bond content of 98.5 mass % or more and a ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography of 2.5 or less is obtained by carrying out a polymerization reaction in conjugated diene compounds using a catalyst composition containing a rare earth element-containing compound or a reaction product of the rare earth element-containing compound with a Lewis base, an aluminoxane and/or organoaluminum compound, and an iodine-containing compound.

Abstract: A method for producing an alkoxysilyl group-containing conjugated diolefin (co)polymer rubber by polymerizing a conjugated diolefin or a conjugated diolefin and an aromatic vinyl compound in a hydrocarbon solvent by anionic polymerization using as an initiator at least one metal compound selected from an organic alkali metal compound and an organic alkali earth metal compound, and then allowing an alkoxysilane-based compound to react, wherein after the alkoxysilane-based compound has been allowed to react, an alkaline compound is added at the time of desolvation, and treatment is conducted at a pH of 8 to 12.

Abstract: The instant invention relates to elastomeric compositions especially useful for manufacturing articles for tires which comprise: (1) at least one butadienic elastomer E, containing a functionalized butadienic elastomer prepared in solution, and modified by a polyfunctional alkoxy silane coupling agent; and (2) a specific precipitated silica having high dispersibility properties and containing aluminium, as at least one reinforcing filler in said butadienic elastomer.

Abstract: A rubber composition comprising: (A) a rubber component including 30 to 100 mass % of diene rubber having at least one functional group selected from the group consisting of an amino group, an alkoxysilyl group, an epoxy group, a hydroxyl group, and a carboxyl group in an amount of 0.01 to 5.0 mmol per 100 g of the diene rubber; (B) silica in an amount of 5 to 130 parts by mass per 100 parts by mass of the rubber component; and (C) an aliphatic component having at least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group, an amino group, and an epoxy group in an amount of 3 to 15 parts by mass per 100 parts by mass of the silica. The rubber composition and a tire using the rubber composition exhibit excellent scorching properties before vulcanization and exhibit excellent rolling resistance and wet skid properties after vulcanization.

Abstract: A process for producing a conjugated diene copolymer rubber which comprises initiating a copolymerization reaction in a reaction system containing a first conjugated diene compound and a first aromatic vinyl compound and completing the reaction, adding a first polyfunctional monomer to the reaction system, optionally further adding a second conjugated diene compound and a second aromatic vinyl compound, and further conducting copolymerization reaction, and adding a modifier to the reaction system to react the modifier with the copolymer. A rubber composition having excellent processability, exhibiting sufficient hardness even after vulcanization, and possessing reduced rolling resistance can be obtained.

Abstract: An objective of the present invention is to provide a block copolymer which is excellent in processability at the time of preparing a rubber composition and leads to a cross-linked rubber composition excellent in tensile property, wearing resistance, weatherability, ozone resistance and heat aging resistance when it is cross-linked, a rubber composition containing the block copolymer and a molded product. The block copolymer of the present invention comprises two polymer blocks each having an ethylenic unsaturated bond and other polymer block which is interposed between two polymer blocks, has a uniform weight average molecular weight in the range from 5,000 to 100,000. The weight average molecular weight of the polymer block having the ethylenic unsaturated bond is preferably in the range from 1,000 to 20,000.

Abstract: An objective of the present invention is to provide a block copolymer which is excellent in processability at the time of preparing a rubber composition and leads to a cross-linked rubber composition excellent in tensile property, wearing resistance, weatherability, ozone resistance and heat aging resistance when it is cross-linked, a rubber composition containing the block copolymer and a molded product. The block copolymer of the present invention comprises two polymer blocks each having an ethylenic unsaturated bond and other polymer block which is interposed between two polymer blocks, has a uniform weight average molecular weight in the range from 5,000 to 100,000. The weight average molecular weight of the polymer block having the ethylenic unsaturated bond is preferably in the range from 1,000 to 20,000.

Abstract: A process for producing a modified polymer which increases low heat buildup and reinforcing capability of a rubber composition and which has excellent abrasion resistance, mechanical characteristics, and processability; a modified polymer obtained by the process; and a rubber composition using the modified polymer are provided. The process comprises a step of carrying out a modification reaction on the active end of a conjugated diene polymer having a vinyl content of below 10%, a cis-1,4 bond content of 75% or higher, and an active end, using an alkoxysilane compound, and a step of carrying out a condensation reaction in the presence of a condensation accelerator comprising a compound of an element belonging to at least one of the groups 4A (excluding Ti), 2B, 3B, and 5B of the periodic table.

Abstract: Disclosed are a conjugated diolefin (co) polymer rubber formed from either a conjugated diolefin or a conjugated diolefin and an aromatic vinyl compound, wherein the (co) polymer rubber has a primary amino group and an alkoxysilyl group which are bonded to a (co) polymer chain; a process for producing the same; a rubber composition; a composite; and a tire. The (co) polymer rubber has satisfactory processability, and can give an automotive tire tread having a balance among wear resistance, failure characteristics, low hysteresis loss and wet-skid characteristics.

Abstract: There is provided a method for producing a conjugated diolefin (co)polymer rubber excellent in processability, independently of the kind and combination of filling agent incorporated, excellent in a balance among wet-skid characteristics, low hysteresis loss, wear resistance and breaking strength, when vulcanization treatment is performed to form a vulcanized rubber, and useful as a material for a tread or a sidewall member of a tire for low fuel consumption, a large sized tire or a high performance tire.

Abstract: A process for producing a conjugated diene copolymer rubber which comprises initiating a copolymerization reaction in a reaction system containing a first conjugated diene compound and a first aromatic vinyl compound and completing the reaction, adding a first polyfunctional monomer to the reaction system, optionally further adding a second conjugated diene compound and a second aromatic vinyl compound, and further conducting copolymerization reaction, and adding a modifier to the reaction system to react the modifier with the copolymer. A rubber composition having excellent processability, exhibiting sufficient hardness even after vulcanization, and possessing reduced rolling resistance can be obtained.