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: There is provided a method of producing a conjugated diene rubber capable of being used as a starting material for a crosslinked rubber that can be used in applications such as tire treads and can raise the fuel efficiency.

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: 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: 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: There is provided a method of producing a conjugated diene rubber capable of being used as a starting material for a crosslinked rubber that can be used in applications such as tire treads and can raise the fuel efficiency.

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 aluminum, as at least one reinforcing filler in said butadienic elastomer.

Abstract: A method for producing a modified conjugated diene polymer includes a modification step (A) that subjects a conjugated diene polymer having a cis-1,4-bond content of 98.5% or more and possessing an active end to a modification reaction to introduce an alkoxysilane compound having two or more reactive groups including an alkoxysilyl group into the active end of the conjugated diene polymer, and a condensation step (B) that subjects the residue of the alkoxysilane compound introduced into the active end to a condensation reaction in the presence of a condensation catalyst that includes at least one element among the elements of the groups 4A, 2B, 3B, 4B, and 5B in the periodic table. The method can produce a modified conjugated diene polymer that exhibits low heat build-up and excellent wear resistance.

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: 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: 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 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: There is obtained a rubber composition excellent in processability of unvulcanized compounded rubber, excellent in wear resistance and wet skid resistance of vulcanized rubber, low in rolling resistance, and suitable for tire applications, particularly for tire tread applications in which importance is given to low fuel consumption and safety. A rubber composition mainly comprising (I) 0.5 to 35% by weight of a conjugated diene-based (co)polymer rubber having an amino group and an alkoxysilyl group on a polymer chain and having a weight average molecular weight of 1,000 to 90,000, and (II) 99.5 to 65% by weight of a conjugated diene-based (co)polymer rubber having a weight average molecular weight of 100,000 to 2,000,000 (with the proviso that (I)+(II)=100% by weight).

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 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: A method for producing a modified conjugated diene polymer includes a modification step (A) that subjects a conjugated diene polymer having a cis-1,4-bond content of 98.5% or more and possessing an active end to a modification reaction to introduce an alkoxysilane compound having two or more reactive groups including an alkoxysilyl group into the active end of the conjugated diene polymer, and a condensation step (B) that subjects the residue of the alkoxysilane compound introduced into the active end to a condensation reaction in the presence of a condensation catalyst that includes at least one element among the elements of the groups 4A, 2B, 3B, 4B, and 5B in the periodic table. The method can produce a modified conjugated diene polymer that exhibits low heat build-up and excellent wear resistance.

Abstract: A method for producing a modified conjugated diene polymer includes carrying out a modification reaction that reacts a modifier that includes a specific compound with a conjugated diene polymer having a cis-1,4-bond content of 98.5% or more and possessing an active end to introduce the modifier into the active end of the conjugated diene polymer to obtain a modified conjugated diene polymer. The modified conjugated diene polymer that exhibits excellent wear resistance, excellent mechanical properties, and reduced cold flow can be obtained by the method.