Abstract: The present invention is to provide a diene polymer that exhibits excellent low rolling resistance when used in a tire, a method for producing the diene polymer, and a rubber composition containing the diene polymer. The diene polymer of an embodiment of the present invention is produced by polymerizing a monomer containing at least a diene monomer by using an initiator prepared from an organolithium compound, an alkyl aluminum, and a metal alcoholate, and then terminating the polymerization by using an electrophile selected from the group consisting of titanium halides, tin halides, cyclic silazanes, alkoxysilanes, epoxides, amines, ketones, and compounds represented by Formula (N) below.

Abstract: A rubber composition for a tire contains 100 parts by mass of a diene rubber (A) and from 1 to 60 parts by mass of an organic microparticle (B); an average particle size of the organic microparticle (B) being from 0.001 to 100 ?m, the organic microparticle (B) having a complex structure composed of a compatible component that is compatible with the diene rubber (A) and an incompatible component that is not compatible with the diene rubber (A), the complex structure having an inner part in which an amount of the incompatible component is greater than an amount of compatible component, and an outer part which covers at least a part of the inner part and in which the amount of the compatible component is greater than an amount of the incompatible component. A pneumatic tire including such rubber composition has a desirable elongation, rigidity, durability, and wear resistance.

Abstract: Provided is a rubber composition for a tire tread, which includes 1 or greater parts by mass and less than 20 parts by mass of a millable silicone rubber compound per 100 parts by mass of a diene rubber, wherein the millable silicone rubber compound has a storage modulus of 0.3 to 10 kPa at a 450% shear strain at 110° C. and a glass transition temperature and a plasticity with a relationship: 14000<(273+Tg)×Pn<82000, where Tg is the glass transition temperature (° C.) and the Pn is the plasticity at 23° C.

Abstract: A rubber composition contains a diene rubber component containing at least 20 mass % of a modified conjugated diene rubber, a silica, and a silane coupling agent; the modified conjugated diene rubber having at least one modified part and at least one conjugated diene rubber part; the conjugated diene rubber part having a conjugated diene copolymer block and an isoprene block containing from 70 mass % to 100 mass % of isoprene units in each conjugated diene rubber part; the modified part bonding to an end of the conjugated diene rubber part and having a functional group which interacts with the silica; a content of the silica being from 60 to 200 parts by mass per 100 parts by mass of the diene rubber component; the silane coupling agent being a polysiloxane represented by formula (1), (A)a(B)b(C)c(D)d(R1)eSiO(4-2a-b-c-d-e)/2, and having a content from 1.0 to 20 mass % of the content of the silica.

Abstract: The present invention provides a rubber composition a tire, by which both low rolling resistance and wet grip performance can be achieved at high levels. This rubber composition for a tire is obtained by blending from 66 to 180 parts by weight of a silica having a nitrogen adsorption specific surface area of from 150 to 400 m2/g into 100 parts by weight of a diene rubber; a size Rss of aggregates of the silica forming a hierarchical structure being from 14 to 23 nm when the rubber composition is measured by ultra-small-angle X-ray scattering and an obtained scattering profile is applied to a Unified-Guinier function.

Abstract: The present invention provides: a rubber composition for tires which has excellent processability and has excellent low heat build-up when formed into a tire; and a pneumatic tire using the same. The rubber composition for tires of the present invention is a rubber composition for tires, the rubber composition containing a diene rubber (A) and a microparticle (B), a vinyl group content of the diene rubber (A) being from 5 to 35 mass %, the microparticle (B) being a mercapto group-containing organic microparticle in which a crosslinkable oligomer or polymer (b1) is crosslinked, an average particle size of the microparticle (B) being from 1 to 200 ?m, and a content of the microparticle (B) being from 1 to 55 parts by mass per 100 parts by mass of the diene rubber (A).

Abstract: Provided is a rubber composition for a tire tread, which includes 1 or greater parts by mass and less than 20 parts by mass of a millable silicone rubber compound per 100 parts by mass of a diene rubber, wherein the millable silicone rubber compound has a storage modulus of 0.3 to 10 kPa at a 450% shear strain at 110° C. and a glass transition temperature and a plasticity with a relationship: 14000<(273+Tg)×Pn<82000, where Tg is the glass transition temperature (° C.) and the Pn is the plasticity at 23° C.

Abstract: Provided are a tire rubber composition capable of producing a pneumatic tire having excellent rigidity and wear resistance and a pneumatic tire using the same. The tire rubber composition includes 100 parts by mass of a diene rubber (A) and from 1 to 50 parts by mass of elastic microparticles (B), wherein the elastic microparticles (B) have a form of microparticles obtained by crosslinking a crosslinkable oligomer or polymer (b1) in water or an organic solvent, or in the diene rubber (A), and have an average particle size of from 0.001 to 100 ?m, the JIS A hardness of a cured product obtained by crosslinking the crosslinkable oligomer or polymer (b1) without use of water, the organic solvent or the diene rubber (A) is greater than 45, and the elongation of the cured product is 200% or greater.

Abstract: A rubber composition for tires comprises a diene rubber, silica, and a silane coupling agent, and is characterized in that a function v of a shear modulus G? of the rubber composition at 0.28% shear stress at 110° C., a CTAB specific surface area (CTAB) of the silica, a volume fraction (?) of the silica in the rubber composition, and a stress at 100% elongation (M100) of the rubber composition satisfies the relationship of the following equation (i): G?=K×v, where K is a coefficient greater than 0 and not greater than 450, and v is represented by the following equation (ii): v=?×(1+0.0258×CTAB×M100) and is a real number not less than 2.5 and not greater than 20.

Abstract: Provided is a rubber composition for a tire tread containing: a diene rubber; silica in an amount of from 60 to 200 parts by mass per 100 parts by mass of the rubber; a polysiloxane represented by the average composition formula: (A)a(B)b(C)c(D)d(R1)eSiO(4-2a-b-c-d-e)/2; and an alkyl triethoxysilane having an alkyl group with from 7 to 20 carbon atoms. Also provided is a pneumatic tire using this rubber composition in the tire tread.

Abstract: Provided are a tire rubber composition capable of producing a pneumatic tire having excellent rigidity and wear resistance and a pneumatic tire using the same. The tire rubber composition includes 100 parts by mass of a diene rubber (A) and from 1 to 50 parts by mass of elastic microparticles (B), wherein the elastic microparticles (B) have a form of microparticles obtained by crosslinking a crosslinkable oligomer or polymer (b1) in water or an organic solvent, or in the diene rubber (A), and have an average particle size of from 0.001 to 100 ?m, the JIS A hardness of a cured product obtained by crosslinking the crosslinkable oligomer or polymer (b1) without use of water, the organic solvent or the diene rubber (A) is greater than 45, and the elongation of the cured product is 200% or greater.

Abstract: A rubber composition for use in tire treads comprising from 60 to 130 parts by weight of silica per 100 parts by weight of diene rubber containing not less than 50% by weight of hydroxyl group-containing modified styrene butadiene rubber, in which the weight ratio of oil to filler containing the silica is not greater than 0.25, and a silane coupling agent having a mercapto group and an Si—O bond is compounded in an amount from 4 to 15% by weight of the silica content, and diethylene glycol is compounded in an amount from 1 to 6% by weight of the silica content.

Abstract: A rubber composition for tires comprises a diene rubber, silica, and a silane coupling agent, and is characterized in that a function v of a shear modulus G? of the rubber composition at 0.28% shear stress at 110° C., a CTAB specific surface area (CTAB) of the silica, a volume fraction ((?) of the silica in the rubber composition, and a stress at 100% elongation (M100) of the rubber composition satisfies the relationship of the following equation (i): G?=K×v, where K is a coefficient greater than 0 and not greater than 450, and v is represented by the following equation (ii): v=?×(1+0.0258×CTAB×M100) and is a real number not less than 2.5 and not greater than 20.

Abstract: A studded tire includes stud pins embedded in a road contact surface of a tread portion 1; the rubber composition forming the tread portion containing at least one of natural rubber, styrene-butadiene rubber, and butadiene rubber, from 5 to 50 parts by weight of carbon black and from 5 to 70 parts by weight of silica per 100 parts by weight of the diene rubber; a nitrogen adsorption specific surface area of the carbon black being from 50 to 120 m2/g; a CTAB specific surface area of the silica being from 80 to 190 m2/g; a rubber hardness of the rubber composition being not greater than 60; and a product of a stress at the time of 400% elongation and a bottom surface area of a flange portion on a bottom side of the stud pins being not less than 400 MPa·mm2 and not greater than 850 MPa·mm2.

Abstract: The present invention provides a rubber composition a tire, by which both low rolling resistance and wet grip performance can be achieved at high levels. This rubber composition for a tire is obtained by blending from 66 to 180 parts by weight of a silica having a nitrogen adsorption specific surface area of from 150 to 400 m2/g into 100 parts by weight of a diene rubber; a size Rss of aggregates of the silica forming a hierarchical structure being from 14 to 23 nm when the rubber composition is measured by ultra-small-angle X-ray scattering and an obtained scattering profile is applied to a Unified-Guinier function.

Abstract: Provided is a rubber composition for a tire tread containing: a diene rubber; silica in an amount of from 60 to 200 parts by mass per 100 parts by mass of the rubber; a polysiloxane represented by the average composition formula: (A)a(B)b(C)c(D)d(R1)eSiO(4-2a-b-c-d-e)/2; and an alkyl triethoxysilane having an alkyl group with from 7 to 20 carbon atoms. Also provided is a pneumatic tire using this rubber composition in the tire tread.

Abstract: Provided is a rubber composition for a tire, comprising: diene rubber contained in a quantity of 100 parts by mass; silica contained in a quantity of 60 to 200 parts by mass; polysiloxanes represented by the average composition formula of Formula (1): (A)a(B)b(C)c(D)d(R1)eSiO(4-2a-b-c-d-e)/2 contained in a quantity from 1 to 20 mass % relative to the quantity of silica; and a thiuram disulfide vulcanization accelerator contained in a quantity from 0.05 to 3.0 parts by mass.

Abstract: Provided is a rubber composition for a tire tread containing: a diene rubber; silica in an amount of from 60 to 200 parts by mass per 100 parts by mass of the rubber; a polysiloxane represented by the average composition formula: (A)a(B)b(C)c(D)d(R1)eSiO(4-2a-b-c-d-e)/2; and an alkyl triethoxysilane having an alkyl group with from 7 to 20 carbon atoms. Also provided is a pneumatic tire using this rubber composition in the tire tread.

Abstract: A rubber composition for a tire tread comprising: a diene rubber; a silica having an N2SA of from 194 to 225 m2/g and a CTAB of from 180 to 210 m2/g; and a polysiloxane represented by the average composition formula of formula (1) and contained in an amount of from 1 to 20 mass % with respect to the quantity of silica. (A)a(B)b(C)c(D)d (R1)3SiO(4-2a-b-c-d-e)/2. Also provided is a pneumatic tire having tire treads formed using the rubber composition.

Abstract: An object of the present invention is to provide a tire rubber composition capable of producing a studless tire that has excellent performance on ice and wear resistance, and to provide a studless tire using the composition. The tire rubber composition of the present invention is composed of 100 parts by mass of a diene type rubber (A), from 30 to 100 parts by mass of a carbon black and/or a white filler (B), from 0.3 to 30 parts by mass of a cross-linkable oligomer or polymer (C) that is not phase-soluble with the diene type rubber (A); and from 0.1 to 12 parts by mass of three dimensionally crosslinked fine particles (D) of 1 to 200 ?m average particle diameter.