Abstract: A production process of a rubber composition containing a modified conjugated diene-based polymer, which can provide a rubber composition in which processability is excellent, and a filling agent, when contained, has favorable dispersibility therein. The production process of the rubber composition includes: a first step of kneading a modified conjugated diene-based polymer that is obtained by polymerizing a monomer containing a conjugated diene compound and has at least one nitrogen-containing functional group selected from a primary amino group, a secondary amino group, a tertiary amino group and groups in which these amino groups have been converted into an onium group, and a basic compound having an acid dissociation constant of 8.0 or more; and a second step of kneading the kneaded product obtained in the first step and a cross-linking agent.

Abstract: A polymer composition including: a filler (A); a polymer (B) having a repeating unit derived from a conjugated diene compound, having a peak temperature of a tan ? temperature dispersion curve of ?110° C. or more and less than ?30° C., and having a functional group capable of interacting with the filler (A); and a polymer (C) having a repeating unit derived from a conjugated diene compound and a repeating unit derived from an aromatic vinyl compound, having a peak temperature of a tan ? temperature dispersion curve of ?30° C. or more and 10° C. or less, and having a functional group capable of interacting with the filler (A), wherein the polymer (B) and the polymer (C) are incompatible with each other, and a concentration of functional groups per unit mass of the polymer (B) is higher than a concentration of functional groups per unit mass of the polymer (C).

Abstract: Provided is a rubber material that is well-balanced in terms of tensile strength, low hysteresis loss property, wet grip property, and abrasion resistance. A hydrogenated conjugated diene-based polymer which is a hydrogenation product of a conjugated diene-based polymer including butadiene-derived structural units is produced by a method comprising a step of preparing a conjugated diene-based polymer having, at a side chain moiety thereof, a functional group capable of interacting with silica; and a step of hydrogenating the conjugated diene-based polymer so as to achieve a hydrogenation rate of 80 to 99% of butadiene-derived structural units included in the conjugated diene-based polymer.

Abstract: The present invention has as its object the provision of a production process of a rubber composition containing a modified conjugated diene-based polymer, which can provide a rubber composition in which processability is excellent, and a filling agent, when contained, has favorable dispersibility therein. The production process of a rubber composition according to the present invention includes: a first step of kneading a modified conjugated diene-based polymer that is obtained by polymerizing a monomer containing a conjugated diene compound and has at least one nitrogen-containing functional group selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group and groups in which these amino groups have been converted into an onium group, and a basic compound having an acid dissociation constant of 8.0 or more; and a second step of kneading the kneaded product obtained in the first step and a cross-linking agent.

Abstract: A polymer composition including: a filler (A); a polymer (B) having a repeating unit derived from a conjugated diene compound, having a peak temperature of a tan ? temperature dispersion curve of ?110° C. or more and less than ?30° C., and having a functional group capable of interacting with the filler (A); and a polymer (C) having a repeating unit derived from a conjugated diene compound and a repeating unit derived from an aromatic vinyl compound, having a peak temperature of a tan ? temperature dispersion curve of ?30° C. or more and 10° C. or less, and having a functional group capable of interacting with the filler (A), wherein the polymer (B) and the polymer (C) are incompatible with each other, and a concentration of functional groups per unit mass of the polymer (B) is higher than a concentration of functional groups per unit mass of the polymer (C).

Abstract: Provided is a rubber material that is well-balanced in terms of tensile strength, low hysteresis loss property, wet grip property, and abrasion resistance. A hydrogenated conjugated diene-based polymer which is a hydrogenation product of a conjugated diene-based polymer including butadiene-derived structural units is produced by a method comprising a step of preparing a conjugated diene-based polymer having, at a side chain moiety thereof, a functional group capable of interacting with silica; and a step of hydrogenating the conjugated diene-based polymer so as to achieve a hydrogenation rate of 80 to 99% of butadiene-derived structural units included in the conjugated diene-based polymer.

Abstract: Provided is a hydrogenated conjugated diene polymer which is a hydrogenated product of a conjugated diene polymer comprising a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, wherein the conjugated diene compound includes butadiene, the hydrogenated conjugated diene polymer is obtained by hydrogenating a polymer in which a vinyl bond content in the structural unit derived from butadiene is 50 mol % or less, an amount of the structural unit derived from the aromatic vinyl compound is 5 to 25 mass % with respect to entire structural units derived from monomers of the polymer, and a hydrogenation rate of the structural unit derived from butadiene is 91% to 99%.

Abstract: Provided is a hydrogenated conjugated diene polymer which is a hydrogenated product of a conjugated diene polymer comprising a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, wherein the conjugated diene compound includes butadiene, the hydrogenated conjugated diene polymer is obtained by hydrogenating a polymer in which a vinyl bond content in structural unit derived from butadiene is 55 mol % or more, and a hydrogenation rate of the structural unit derived from butadiene is 91% to 99%.

Abstract: Provided is a hydrogenated conjugated diene polymer which is a hydrogenated product of a conjugated diene polymer having a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound, wherein the conjugated diene compound includes butadiene, an amount of the structural unit derived from the aromatic vinyl compound is 30 mass % or more with respect to entire structural units derived from monomers of the polymer, and a hydrogenation rate of the structural unit derived from butadiene is 80% to 99%.

Abstract: A rubber composition by which a rubber elastic body having both of excellent low rolling resistance and wet skid resistance and also having excellent mechanical strength and wear resistance can be obtained, a rubber elastic body, a tire, and a block copolymer are provided. The rubber composition of the present invention comprises a block copolymer (A) comprising a block (a-1) of a conjugate diene and an aromatic vinyl and a block (a-2) of a conjugate diene or the diene and an aromatic vinyl, a specific polymer (B) other than the copolymer, and a filler (C), wherein the block copolymer (A) has a specific functional group; the block copolymer (A) has two glass transition temperatures separated from each other by 5° C. or more within a range of ?100 to 20° C. in measurement in accordance with ASTM D3418; and the ratio of the block copolymer (A) is 10% by mass or more when the sum of the block copolymer (A) and the polymer (B) is taken as 100% by mass.

Abstract: By a method comprising a process including (a) producing a modified conjugated diene polymer through reaction of a conjugated diene polymer having an alkali metal or alkaline-earth metal active terminal with a first alkoxysilane compound which has both an alkoxysilyl group and at least one group convertible into an onium, and (b) mixing the modified conjugated diene polymer, an agent for producing onium, a second alkoxysilane compound having an alkoxysilyl group and at least one group convertible into an onium and a condensation catalyst containing metal element(s) for alkoxysilane compounds, conjugated diene rubber usable as a starting material of cross-linked rubber which is used for a tire tread or the like and allows enhancement of low fuel consumption property can be obtained.

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 process for producing a modified conjugated diene based polymer includes a step (a) of reacting a silicon compound with a conjugated diene based polymer having an active end so that the reaction takes place at the active end, the silicon compound having a protected primary amino group in the molecule thereof and a silicon atom to which a hydrocarbyloxy group and a reactive group are bonded, to thereby modify the active end, and a step (b) of performing condensation reaction, in the presence of a titanium compound serving as a titanium-based condensation-accelerating agent. A rubber composition contains the modified diene polymer, and a tire is produced from the rubber composition.

Abstract: A rubber composition by which a rubber elastic body having both of excellent low rolling resistance and wet skid resistance and also having excellent mechanical strength and wear resistance can be obtained, a rubber elastic body, a tire, and a block copolymer are provided. The rubber composition of the present invention comprises a block copolymer (A) comprising a block (a-1) of a conjugate diene and an aromatic vinyl and a block (a-2) of a conjugate diene or the diene and an aromatic vinyl, a specific polymer (B) other than the copolymer, and a filler (C), wherein the block copolymer (A) has a specific functional group; the block copolymer (A) has two glass transition temperatures separated from each other by 5° C. or more within a range of ?100 to 20° C. in measurement in accordance with ASTM D3418; and the ratio of the block copolymer (A) is 10% by mass or more when the sum of the block copolymer (A) and the polymer (B) is taken as 100% by mass.

Abstract: By a method comprising a process including (a) producing a modified conjugated diene polymer through reaction of a conjugated diene polymer having an alkali metal or alkaline-earth metal active terminal with a first alkoxysilane compound which has both an alkoxysilyl group and at least one group convertible into an onium, and (b) mixing the modified conjugated diene polymer, an agent for producing onium, a second alkoxysilane compound having an alkoxysilyl group and at least one group convertible into an onium and a condensation catalyst containing metal element(s) for alkoxysilane compounds, conjugated diene rubber usable as a starting material of cross-linked rubber which is used for a tire tread or the like and allows enhancement of low fuel consumption property can be obtained.

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: 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: 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: 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: 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.