Sumitomo Rubber Industries Limited

Shin-etsu Chemical Co., Ltd.

Soh Ishino

Kazuya Torita

Tatsuya Miyazaki

Daisuke Sato

Yuhei Yamashiro

Takayuki Hattori

Munenao Hirokami

Hiroyuki Kishimoto

Ryoji Kojima

Takao Wada

Yuka Yokoyama

Ryota Kitago

Ryuichi Tokimune

Tsuyoshi Tsuchida

Tetsuro Yamada

Takayuki Nagase

Masanobu Nakamura

Masaki Oshimo

Takeo Nakazono

Mikako Takenaka

Ryoji Matsui

Yuuki Kawana

Naoya Kitamura

Ayuko Yamana

Hisataka Kajita

Provided are a method for manufacturing a rubber composition for a tire and a method for manufacturing a tire including this manufacturing method for the rubber composition in the present invention, which are characterized by including the steps of: starting to knead a rubber component, a sulfur donor, and a sulfur atom-containing vulcanization accelerator together before kneading the rubber component with a filler; and then adding a filler to an obtained kneaded product and performing kneading at a kneading temperature of 120&#xb0; C. or higher. According to the manufacturing methods of the present invention, a rubber composition for a tire and a tire which have good fracture property can be manufactured.

Method for manufacturing rubber composition for tire and method for manufacturing tire

Provided are a rubber composition for tires which achieves both abrasion resistance and processability while maintaining fuel economy, and a pneumatic tire including the rubber composition. A rubber composition for tires, containing an organosilicon compound represented by the average compositional formula (I) below having a ratio of the number of sulfur atoms to the number of silicon atoms of 1.0 to 1.5, wherein x represents the average number of sulfur atoms; m represents an integer of 6 to 12; and Rto Rare the same or different and each represent a C1-C6 alkyl or alkoxy group, at least one of Rto Rand at least one of Rto Rare the alkoxy groups, and two or more of the alkyl or alkoxy groups for Rto Rmay be joined to form a ring.

Rubber composition for tires and pneumatic tire

The present invention provides a pneumatic tire with well improved fuel economy, rubber tensile strength, and abrasion resistance. The present invention relates to a pneumatic tire formed from a rubber composition, the rubber composition containing: a hydrogenated copolymer obtained by copolymerization of an aromatic vinyl compound and a conjugated diene compound, the hydrogenated copolymer having a degree of hydrogenation of the conjugated diene units of 75 mol % or more; silica; and a silane coupling agent 1 containing a carbonylthio group (&#x2014;S&#x2014;C(&#x2550;O)&#x2014;) but no mercapto group (&#x2014;SH) and/or a silane coupling agent 2 containing a mercapto group (&#x2014;SH), the rubber composition containing, per 100% by mass of a rubber component, 75% by mass or more of the hydrogenated copolymer.

Pneumatic tire

The present invention aims to provide pneumatic tires that can achieve both abrasion resistance and low heat build-up properties. The present invention relates to a pneumatic tire including a tread formed from a rubber composition, the rubber composition containing: a rubber component including an isoprene-based rubber and a high-cis polybutadiene rubber having a cis content of 90% by mass or more; one or more types of carbon black; and sulfur, at least one of the one or more types of carbon black being produced from a feedstock oil that has a BMCI value of 150 or less and an aliphatic hydrocarbon content of 30% by mass or more, the BMCI value being calculated from the average boiling point T (&#xb0; C.) and the specific gravity D (60/60&#xb0; F.) relative to water at 60&#xb0; F. according to the equation below,=48,640/(+273)+473.7&#x2212;456.8.

Rubber composition and pneumatic tire

Provided is a rubber composition for a tire having improved abrasion resistance, fuel economy and processability in a balanced manner. Also provided is a method for producing the rubber composition, and a pneumatic tire formed from the rubber composition. The rubber composition for a tire is obtained by mixing a kneaded mixture containing butadiene rubber, silica, a silane coupling agentwith a sulfur content of 20% by mass or more, and oil; styrene-butadiene rubber; and a silane coupling agentwith a sulfur content of less than 20% by mass.

Rubber composition for tire, and pneumatic tire

Provided are: a rubber composition for tires capable of improving fuel economy, wet grip performance, and abrasion resistance; and a pneumatic tire including the same. Included is a rubber composition for tires including: a diene polymer; silica; and a liquid resin having a softening point of &#x2212;20 to 20&#xb0; C., the diene polymer being a modified diene polymer obtained by reacting components (A) and (B), the liquid resin being present in an amount of 3-40 parts by mass per 100 parts by mass of the rubber component, the component (A) being an active alkali metal-terminated conjugated diene polymer obtained by polymerizing a conjugated diene monomer alone or with an aromatic vinyl monomer, in the presence of a component (C), the component (B) being a modifier containing a functional group, the component (C) being a chemical species obtained by reacting an organic alkali metal compound and a compound of Formula (1) below. 

Rubber composition for tires, and pneumatic tire

Provided is a pneumatic tire including a tread formed from a specified rubber composition, thereby achieving a balanced improvement in fuel economy, wet-grip performance, and abrasion resistance while simultaneously having excellent durability. The present invention relates to a pneumatic tire including a tread formed from a rubber composition, the rubber composition containing: an oil-extended BR having a cis content of 95 mol % or more, a vinyl content of 1 mol % or less, and a weight average molecular weight of 530,000 or more; a SBR having a bound styrene content of 30-50% by mass and a weight average molecular weight of 700,000 or more; silica; and carbon black, the oil-extended BR being synthesized using a rare earth catalyst, the rubber composition containing, based on 100% by mass of rubber solids, 10-67% by mass of the BR component contained in the oil-extended BR and 10-50% by mass of the SBR.

The invention provides a rubber composition for tires, enabling a balanced improvement of processability, rubber strength, fuel economy, and crack growth resistance; and a pneumatic tire formed from the rubber composition. The invention relates to a rubber composition for tires, including: a butadiene rubber (a) having a cis content of 96% by mass or more, a Mooney viscosity of 35 to 75, and a ratio of (Weight average molecular weight (Mw))/(Number average molecular weight (Mn)) of 2.7 or less; and a butadiene rubber (b) containing 1,2-syndiotactic polybutadiene crystals with a melting point of 90 to 140&#xb0; C., and having a weight average molecular weight of 50,000 to 500,000.

Provided are a rubber composition achieving balanced improvement in processability, fuel economy, rubber strength, abrasion resistance, wet-grip performance, and handling stability, and a pneumatic tire including the composition. The rubber composition includes, per 100% by mass of a rubber component, at least 35% by mass of SR, the composition including a conjugated diene polymer and a silica having NSA of 40-400 m/g, the polymer being obtained by polymerizing a monomer component including a conjugated diene compound and a silicon-containing vinyl compound using a polymerization initiator of formula (I): to produce a copolymer, and reacting a compound containing nitrogen and/or silicon atoms with an active terminal of the copolymer, wherein the amount of the diene polymer is 1-90% by mass and the amount of polyisoprene-based rubber is 0-40% by mass, each per 100% by mass of the rubber component, and the amount of the silica is 10-150 parts by mass per 100 parts by mass of the rubber component.

Rubber composition, and pneumatic tire

Provided are: a rubber composition a achieving balanced improvement in processability, fuel economy, rubber strength, abrasion resistance, wet-grip performance, and handling stability, and a pneumatic tire including the composition. Included is a rubber composition including a conjugated diene polymer and a silica having NSA of 40-400 m/g, the diene polymer being obtained by polymerizing a monomer component including a conjugated diene compound and a silicon-containing vinyl compound in the presence of a polymerization initiator of formula (I): to produce, a copolymer, and reacting a compound containing nitrogen and/or silicon atoms with an active terminal of the copolymer, wherein the amount of the diene polymer is 1-90% by mass and the amount of a polyisoprene-based rubber is 0-70% by mass, each per 100% by mass of the rubber component, and the amount of the silica is 10-150 parts by mass per 100 parts by mass of the rubber component.

Provided are a rubber composition for tires which provides both adhesion to fiber cords and conductivity even when an inexpensive conductive carbon black is used, and thus achieves a balanced improvement in conductivity, handling stability, fuel economy, elongation at break, adhesion to fiber cords, processability, and tire durability; and a pneumatic tire including the composition. The composition includes, per 100 parts by mass of a rubber component: 1.0-3.5 parts by mass of sulfur with an iron content of 30 ppm or less, calculated as the net sulfur content in the sulfur; and 0.5-15 parts by mass of conductive carbon black having a DBP of 300 ml/100 g or more and an iron content of 60 ppm or more, the composition having a total net sulfur content of 1.0-6.0 parts by mass per 100 parts by mass of the rubber component, and a volume resistivity of 1.0&#xd7;10&#x3a9;&#xb7;cm or less.

The present invention provides a rubber composition for a tread, having improved abrasion resistance, heat aging resistance, processability, and fuel economy in a balanced manner, and a pneumatic tire formed therefrom. The present invention relates to a rubber composition for a tread, comprising a rubber component, silica, a silane coupling agent, a sulfur vulcanizing agent, a sulfenamide or thiazole vulcanization accelerator 1, and a thiuram vulcanization accelerator 2.

Rubber composition for tread, and pneumatic tire

Provided are a rubber composition for a tire which achieves a balanced improvement in tensile properties at break and fuel economy while providing excellent conductivity; and a pneumatic tire including the rubber composition. The present invention relates to a rubber composition for a tire, including: a rubber component; a carbon black having a nitrogen adsorption specific surface area of 20 to 110 m/g and a DBP oil absorption of 60 to 130 ml/100 g; and a conductive carbon black having a nitrogen adsorption specific surface area of 900 m/g or larger, a DBP oil absorption of 300 ml/100 g or more, and a volatile content of 0.8% by mass or more, the rubber composition containing 0.1 to 3 parts by mass of the conductive carbon black per 100 parts by mass of the rubber component.

Provided are a rubber composition achieving balanced improvement in processability, fuel economy, rubber strength, abrasion resistance, and wet-grip performance, and a pneumatic tire thereof. The rubber composition includes a conjugated diene polymer and a silica having NSA of 40-400 m/g, the polymer being obtained by polymerizing a monomer component including a conjugated diene compound and a silicon-containing vinyl compound in the presence of a polymerization initiator of formula (I): to produce a copolymer, and reacting a compound containing nitrogen and/or silicon atoms with an active terminal of the copolymer, wherein the amount of the diene polymer is 1-60% by mass and the amount of polyisoprene-based rubber is 0-99% by mass, each per 100% by mass of the rubber component; the amount of the silica is 10-80 parts by mass per 100 parts by mass of the rubber component; and the composition has a carbon ratio of at least 50.

Provided are: a tire rubber composition improving fuel economy and abrasion resistance while maintaining good wet-grip performance or improving it; and a pneumatic tire including the same. The composition contains: a rubber component including a diene polymer (1); silica; and a diene polymer (2), the polymers (1) and (2) being modified diene polymers obtained by reacting components (A)-(B), the polymer (1) having a Mn of 110000-1500000, the polymer (2) having a Mn of 1000-100000, the amount of polymer (2) being 2-25 parts by mass per 100 parts by mass of the rubber component, wherein (A): an active alkali metal-terminated conjugated diene polymer obtained by polymerizing a conjugated diene monomer alone or with an aromatic vinyl monomer, in the presence of a component (C); (B): a modifying agent containing a functional group; (C): a chemical species obtained by reacting an organic alkali metal compound with a compound of formula (1): 

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Kobe, Japan

Soh Ishino