Abstract: The present invention has its object to provide a rubber composition for a cap tread capable of improving the performance on snow and ice and the wet performance in good balance, and a studless tire having a cap tread produced from the rubber composition. The present invention relates to a rubber composition for a cap tread, including a rubber component that contains epoxidized natural rubber and butadiene rubber, the rubber component containing 1 to 85% by mass of the epoxidized natural rubber, based on 100% by mass of the rubber component, and the epoxidized natural rubber having an epoxidation degree of 1.5 to 40 mol %.

Abstract: Provided are a rubber composition that makes it possible to improve heat resistance and particularly suppress changes in the properties (e.g. hardness) of the vulcanized rubber composition with long-term use (rubber hardening degradation) to suppress a reduction in performance on snow and ice to extend the life-span, without increase in the antioxidant amount, achieve good performance on snow and ice, wet-grip performance, and abrasion resistance, and reduce curing time and enhance cross-linking efficiency; and a winter tire including a cap tread produced from the composition. The rubber composition for a cap tread comprises a rubber component containing an isoprene-based rubber and butadiene rubber; silica; aromatic oil; a compound represented by formula (I) and/or formula (II); and a thiuram vulcanization accelerator, wherein the amount of silica is 15-80 parts by mass, and the amount of aromatic oil is 15-80 parts by mass, per 100 parts by mass of the rubber component.

Abstract: The present invention aims to provide a rubber composition for a tire which can improve the performance on snow and ice, abrasion resistance and tensile strength in a well-balanced manner. The present invention also aims to provide a method for producing the rubber composition and a studless tire having a cap tread produced from the rubber composition. The rubber composition for a tire is obtainable by mixing a rubber component containing natural rubber and butadiene rubber with silica at a temperature of 70 to 130° C. to form a mixture, and keeping the mixture at a temperature of 150 to 200° C.

Abstract: The present invention provides a rubber composition for a studless tire capable of improving the performance on snow and ice, wet performance, abrasion resistance in good balance, and a studless tire having a tread produced from the rubber composition. The rubber composition for a studless tire includes a rubber component including modified natural rubber and butadiene rubber; aromatic oil; silica; and carbon black, wherein the amount of the aromatic oil is 15 to 80 parts by mass and the amount of the silica is 15 to 80 parts by mass, relative to 100 parts by mass of the rubber component.

Abstract: The present invention provides a tread rubber composition for a studless tire having favorable performance on ice and snow and excellent abrasion resistance while reducing strain dependence of hardness of the tread rubber and maintaining rigidity on roads that are not covered with snow and relates to a tread rubber composition for a studless tire, which comprises a diene rubber containing, in a total amount of 80% by mass or more, natural rubber and polybutadiene rubber; silica in an amount of 10 to 150 parts by mass per 100 parts by mass of the diene rubber; and carbon black in an amount of 3 to 50 parts by mass per 100 parts by mass of the diene rubber, wherein the diene rubber contains 10% by mass or more of a polybutadiene rubber modified by a compound represented by the formula (I): R1, R2 and R3 being independently an alkyl group, analkoxy group, a silyloxy group, an acetal group, a carboxyl group, a mercapto group, or a derivative thereof; R4 and R5 being independently a hydrogen atom or an alkyl g

Abstract: The present invention provides a rubber composition for a studless tire, which can achieve sufficient abrasion resistance, performance on ice and snow, and wet grip performance in a balanced manner, and a studless tire having a tread produced from the above composition. The rubber composition for a studless tire contains a rubber component including natural rubber and butadiene rubber; aromatic oil; silica; and carbon black, wherein the total amount of the natural rubber and the butadiene rubber is 30% by mass or more based on 100% by mass of the rubber component, the amount of the aromatic oil is 12-85 parts by mass and the amount of the silica is 12-85 parts by mass, per 100 parts by mass of the rubber component, and the proportion of the silica is 45% by mass or more based on 100% by mass of the total of the silica and the carbon black.

Abstract: The present invention provides a rubber composition for a studless tire and a high-performance studless tire produced therefrom, which achieve good braking force and handling stability on ice and snow. The rubber composition for a studless tire includes: a rubber component; a zinc salt of a C4-C12 aliphatic carboxylic acid, or a C4-C12 aliphatic carboxylic acid and zinc oxide; and an oil or a plasticizer. The rubber component contains 40% by mass or more of butadiene rubber per 100% by mass of the rubber component.

Abstract: The invention provides a rubber composition for studless tire achieving well-balanced abrasion resistance, performance on ice and snow, handling stability, and wet grip performance; and a studless tire including a tread produced from the composition. The composition contains: a rubber component; aromatic oil; silica; carbon black; and a mixture of a zinc salt of aliphatic carboxylic acid and a zinc salt of aromatic carboxylic acid, wherein the total of NR and BR in 100% by mass of the rubber component is 30% by mass or more, the amount of aromatic oil is 12-85 parts by mass, the amount of silica is 12-85 parts by mass, and the amount of mixture is 1 part by mass or more, per 100 parts by mass of the rubber component, and the proportion of silica is 45% by mass or more per 100% by mass of the total of the silica and carbon black.

Abstract: The present invention aims to provide a rubber composition that improves heat resistance and particularly inhibits the changes in properties such as hardness of the vulcanized rubber composition (rubber hardening degradation) due to long-term use without an increased amount of an age resistor, thereby extending the life-span without deterioration of performance on ice, and reduces vulcanization time while maintaining good scorch resistance, and increases cross-linking efficiency; and a studless tire having a cap tread produced from the composition. The rubber composition for a cap tread of the invention comprises: a rubber component containing an isoprene-based rubber; silica; a compound represented by formula (I) and/or (II); and a thiuram vulcanization accelerator, wherein R1 and R2 may be the same or different, and each represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, provided that the case where R1 and R2 are simultaneously hydrogen atoms is excluded.

Abstract: The object of the present invention is to provide a rubber composition suitable for a studless tire, which can inhibit rubber hardness increase with time and reveals excellent performance on ice and snow for a long time. The present invention relates to a rubber composition comprising 1 to 60 parts by weight of hydrogenized liquid polybutadiene based on 100 parts by weight of a rubber component containing at least 80% by weight of a natural rubber and a butadiene rubber, wherein a peak temperature of tan ? is at most 45° C. and rubber hardness at 0° C. is at most 64.

Abstract: The present invention has its object to provide a rubber composition for a cap tread capable of improving the performance on snow and ice and the wet performance in good balance, and a studless tire having a cap tread produced from the rubber composition. The present invention relates to a rubber composition for a cap tread, including a rubber component that contains epoxidized natural rubber and butadiene rubber, the rubber component containing 1 to 85% by mass of the epoxidized natural rubber, based on 100% by mass of the rubber component, and the epoxidized natural rubber having an epoxidation degree of 1.5 to 40 mol %.

Abstract: The present invention provides a rubber composition for a studless tire, which can achieve sufficient abrasion resistance, performance on ice and snow, and wet grip performance in a balanced manner, and a studless tire having a tread produced from the above composition. The rubber composition for a studless tire contains a rubber component including natural rubber and butadiene rubber; aromatic oil; silica; and carbon black, wherein the total amount of the natural rubber and the butadiene rubber is 30% by mass or more based on 100% by mass of the rubber component, the amount of the aromatic oil is 12-85 parts by mass and the amount of the silica is 12-85 parts by mass, per 100 parts by mass of the rubber component, and the proportion of the silica is 45% by mass or more based on 100% by mass of the total of the silica and the carbon black.

Abstract: The present invention provides a rubber composition for a studless tire and a high-performance studless tire produced therefrom, which achieve good braking force and handling stability on ice and snow. The rubber composition for a studless tire includes: a rubber component; a zinc salt of a C4-C12 aliphatic carboxylic acid, or a C4-C12 aliphatic carboxylic acid and zinc oxide; and an oil or a plasticizer. The rubber component contains 40% by mass or more of butadiene rubber per 100% by mass of the rubber component.

Abstract: The present invention provides a rubber composition for a cap tread that can improve steering stability on a snowy road and a pneumatic tire having a cap tread using the rubber composition. The rubber composition for a cap tread comprises 5 to 200 parts by weight of a carbon black having an iodine adsorption amount of 100 to 300 mg/g, and 2 to 50 parts by weight of a silicone oil based on 100 parts by weight of at least one diene rubber selected from the group consisting of a natural rubber, an isoprene rubber, a styrene-butadiene rubber and a butadiene rubber, and 1 to 20 parts by weight of a silane coupling agent based on 100 parts by weight of the silicone oil, and the pneumatic tire having a cap tread is prepared by using the rubber composition.

Abstract: A rubber composition controlling the increase of aging hardness of a studless tire and keeping good performance on snow and ice for long period is provided. A rubber composition for a studless tire including at most 0.5 part by weight of sulfur and 1 to 30 parts by weight of an organic vulcanizing agent satisfying the general formula (1): —(R—Sx)n—??(1) (wherein R is (CH2—CH2—O)m—CH2—CH2, x is an integer of 3 to 6, n is an integer of 10 to 400 and m represents an integer of 2 to 5) based on 100 parts by weight of a rubber component, wherein the content of a natural rubber and/or a polybutadiene rubber is at least 80% by weight in the rubber component, and tan ? peak temperature Tg is at most ?50° C. and rubber hardness at 0° C. is at most 64.

Abstract: It is an object of the present invention to lessen strain dependency of hardness of a tread rubber used for a studless tire, have good performance on snow and ice while securing rigidity on non-snow roads, and improve abrasion resistance. The present invention provides a rubber composition for tread used for a studless tire comprising 30 to 150 parts by weight as a total of (1) silica with a nitrogen absorption specific surface area of at most 100 m2/g and (2) silica with a nitrogen absorption specific surface area of at least 180 m2/g based on 100 parts by weight of a rubber component in which a content of a natural rubber and/or a polybutadiene rubber is at least 80% by weight, wherein contents of silica (1) and silica (2) satisfy the formula below: [Content of silica (1)]×0.2?[Content of silica (2)]?[Content of silica (1)]×6.5, tan ? peak temperature Tg is at most ?50° C., and rubber hardness at 0° C. is at most 64.

Abstract: The present invention has its object to provide a tread rubber composition for a studless tire having favorable performance on ice and snow and excellent abrasion resistance while reducing strain dependence of hardness of the tread rubber and maintaining rigidity on roads that are not covered with snow. The present invention relates to a tread rubber composition for a studless tire, which comprises a diene rubber containing, in a total amount of 80% by mass or more, natural rubber and polybutadiene rubber; silica in an amount of 10 to 150 parts by mass per 100 parts by mass of the diene rubber; and carbon black in an amount of 3 to 50 parts by mass per 100 parts by mass of the diene rubber. The diene rubber contains 10% by mass or more of a polybutadiene rubber modified by a compound represented by the formula (1).

Abstract: The method of manufacturing a studless tire according to the present invention includes a first step, a second step and a third step. In the first step, a kneaded substance is obtained by kneading a composite rubber component containing mineral oil-extended butadiene rubber and a compounding ingredient excluding sulfur and a vulcanization accelerator. In the second step, an unvulcanized rubber composition is obtained by kneading the kneaded substance while adding sulfur and a vulcanization accelerator thereto. In the third step, the unvulcanized rubber composition is vulcanized in a mold for a tire tread under pressurization and/or heating.

Abstract: The present invention has its object to provide a high performance studless tire for a passenger vehicle which has both good braking force and high handling stability on ice or snow. The studless tire for a passenger vehicle comprises a tread having a total sulfur content of 0.7% by mass or less and having a crosslink density of 2.0×10?5 mol/cm3 or higher.

Abstract: The present invention has its object to provide a high performance studless tire, which has both good braking force and high handling stability on ice or snow, at higher productivity and at a lower price for customers. The studless tire comprises a tread made of a rubber composition containing 2.2 to 10 parts by mass of a fatty acid and/or a derivative of the fatty acid per 100 parts by mass of a rubber component, the tread having a JIS-A hardness of 50 or less.