Sumitomo Rubber Industries Limited

Tatsuhiro Tanaka

Kenichi Uesaka

Takayuki Nagase

Kazuyuki Nishioka

Takahiro Kawachi

Masako Nakatani

Keiji Ikeda

Tetsuya Kunisawa

Isamu Tsumori

Subaru Toya

Ayuko Yamada

Naoya Omura

Kazuhisa Fushihara

Takahiro Mabuchi

Yukino Inoue

Hiroshi Ito

Takuya Horiguchi

Takafumi Taguchi

Shuichiro Ono

Toshifumi Haba

Keiji Takagi

Kenya Watanabe

Tsuyoshi Tsuchida

Fumiya Kato

Toru Iizuka

Tetsuya Maekawa

Keiichi Nakadera

Kenji Hamamura

Nanaho Kami

Noboru Okabe

Reika Otake

Yumi Sakaguchi

Daiki Mukouguchi

A pneumatic tireincludes a carcassextending between bead cores of bead portions via a tread portionand sidewall portions, and a belt layerarranged on an outer side in a tire radial direction of the carcassand inside the tread portion. The pneumatic tirehas a noise damperarranged on an inner cavity surface of the tread portion. Glass transition temperature of the noise damperis in a range of from −55 degrees Celsius to −45 degrees Celsius.

Pneumatic tire

A tire in which an elongation at break and/or compounding of a rubber composition of a tread.

Provided are tires that are excellent in tire properties such as fuel economy, abrasion resistance, wet grip performance, snow and ice performance, fracture resistance, and flex crack growth resistance. Included is a tire containing a rubber composition containing a natural rubber derived from-having a weight average molecular weight (Mw) of 5,000,000 or more and including polymers having a radius of gyration (Rz) of 130 nm or larger, wherein the Mw and Rz values are measured by FFF-MALS.

Tires

Provided are a tread rubber composition that provides a balanced improvement of fuel economy, fracture strength, and abrasion resistance, and a pneumatic tire including the rubber composition. The present invention relates to a tread rubber composition including: a rubber component; a silica having a nitrogen adsorption specific surface area of 220 m/g or more; and a mercapto silane coupling agent, the tread rubber composition satisfying the following relationship (A):()*(4%)&#x2212;*(64%)&#x2264;150[]wherein G*(4%) is the shear modulus at an applied strain of 4% at 100&#xb0; C., and G*(64%) is the shear modulus at an applied strain of 64% at 100&#xb0; C.

Tread rubber composition and pneumatic tire

A preparation method of a rubber composition for a tire assures that good processability can be obtained even if a silane coupling agent having a mercapto group is blended. The preparation method of a rubber composition for a tire characterized by initiating kneading of a rubber component and a compound of the formula (1) before kneading the rubber component and a silane coupling agent having a mercapto group. (Wherein Rrepresents a straight-chain or branched chain alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms, and Rand Rtogether with nitrogen bonded thereto form a succinimide group, a maleimide group or a phthalimide group.)

Preparation method of rubber composition for tire and production method of tire

To be capable of preventing deterioration of uniformity after puncture repair while suppressing running noise. [Solution] A pneumatic tirecomprises a noise damperfixed to a tire inner cavity surface of a tread portionand formed of a porous material. The noise damperincludes a first partarranged on an outer side in a tire radial direction and fixed to the tire inner cavity surface, and a second partarranged on an inner side in the tire radial direction of the first partand exposed in a tire inner cavity. A water absorption rate of the first partcalculated by a following formula (1) is in a range of from 5% to 25%. Air permeability of the second partmeasured in accordance with Japanese Industrial Standard JIS-L1096 is in a range of from 1 to 7 cm3/cm2/s. The formula (1) is:water absorption rate (%)=weight change before and after immersion (g)/volume at 50% compression (cm3)&#xd7;100 &#x2003;&#x2003;(1).

A preparation method of a rubber composition for a tire assures that good processability can be obtained even if a silane coupling agent having a mercapto group is blended. The preparation method of a rubber composition for a tire is characterized by initiating kneading of a rubber component and a compound represented by the following formula (1) before kneading the rubber component and a silane coupling agent having a mercapto group. (Wherein each of Rto Rindependently represents a straight-chain or branched chain alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms.)

A preparation method of a rubber composition for a tire assures that good processability can be obtained even if a silane coupling agent having a mercapto group is blended. The preparation method of a rubber composition for a tire is characterized by initiating kneading of a rubber component and a specific polysulfide compound before kneading the rubber component and a silane coupling agent having a mercapto group.

The present invention provides a pneumatic tire provided with a tread formed from a rubber composition that can achieve balanced improvements in fuel economy and wet-grip performance. The present invention relates to a pneumatic tire provided with a tread formed from a rubber composition, the rubber composition containing a rubber component, silica, and a specific silane coupling agent, the rubber component containing, based on 100% by mass of the rubber component, not less than 5% by mass of a conjugated diene polymer containing a constituent unit based on a conjugated diene and a specific constituent unit, at least one terminal of the polymer being modified with a specific compound, the rubber composition containing the silica in an amount of 5 to 150 parts by mass relative to 100 parts by mass of the rubber component.

The present invention provides a rubber composition that can enhance the fuel economy, wet-grip performance, and abrasion resistance in a balanced manner, and a pneumatic tire using this rubber composition. The present invention relates to a rubber composition that contains a rubber component, silica, and a liquid resin having a softening point of &#x2212;20 to 20&#xb0; C., wherein the rubber component contains, based on 100% by mass of the rubber component, not less than 5% by mass of a conjugated diene polymer containing a constituent unit based on a conjugated diene and a constituent unit represented by formula (I) below, at least one terminal of the polymer being modified with a specific compound; and an amount of the silica is 5 to 150 parts by mass per 100 parts by mass of the rubber component. 

Rubber composition and pneumatic tire

The present invention provides a rubber composition that can enhance the fuel economy, wet-grip performance, abrasion resistance, and kneading processability in a balanced manner, and a pneumatic tire using this rubber composition. The present invention relates to a rubber composition that contains a rubber component and silica, wherein the rubber component contains, based on 100% by mass of the rubber component, 10 to 70% by mass of a high-cis polybutadiene having a cis content of 95% by mass or more and satisfying the following requirements (A) to (C): (A) a Mooney viscosity (ML) of 40 to 49; (B) a molecular weight distribution (weight-average molecular weight (Mw)/number-average molecular weight (Mn)) of 3.0 to 3.9; and (C) an index (n-value in Expression (1) below) of velocity dependence of Mooney viscosity of 2.3 to 3.0, and 30 to 90% by mass of a conjugated diene polymer containing a constituent unit based on a conjugated diene and a constituent unit represented by formula (I) below, and an amount of the silica is 5 to 150 parts by mass per 100 parts by mass of the rubber component,log()=log()+&#xd7;log()&#x2003;&#x2003;(Expression 1)wherein RS indicates the number of revolutions per minute of a rotor, K indicates an arbitrary number, and ML indicates a Mooney viscosity, 

The present invention provides a rubber composition that can enhance the fuel economy, wet-grip performance, and abrasion resistance in a balanced manner, and a pneumatic tire using this rubber composition. The present invention relates to a rubber composition that contains a rubber component, silica, and a silane coupling agent, wherein the rubber component contains, based on 100% by mass of the rubber component, not less than 5% by mass of a conjugated diene polymer containing a constituent unit based on a conjugated diene and a constituent unit represented by formula (I) below, at least one terminal of the polymer being modified with a specific compound; an amount of the silica is 5 to 150 parts by mass per 100 parts by mass of the rubber component; and the silane coupling agent contains a mercapto group. 

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Kobe, Japan

Tatsuhiro Tanaka