Sumitomo Rubber Industries Limited

Daisuke Sato

Yuka Yokoyama

Takahiro Mabuchi

Soh Ishino

Ryota Kitago

Kenya Watanabe

Sumiko Miyazaki

Masaki Oshimo

Kazuya Torita

Shogo Hirao

Shoko Mori

Ayaka Kitao

The present invention provides a pneumatic tire having excellent fuel efficiency, handling stability, and ride quality while maintaining a good balance between them. Provided is a pneumatic tire including a tire component formed from a rubber composition, the rubber composition having cured rubber properties satisfying predetermined values.

Pneumatic tire

The present invention provides a rubber composition capable of improving fuel economy and wet grip performance while maintaining good processability, abrasion resistance and handling stability or improving them, as well as a pneumatic tire including the rubber composition. The rubber composition contains carbon black, silica, and a polymer mixture obtained by modifying a polymer derived from a conjugated diene compound and/or an aromatic vinyl compound with a compound containing an ester group and/or a carboxyl group, the polymer mixture having a weight average molecular weight of from 1.0&#xd7;10to 1.0&#xd7;10, the rubber composition having a tan &#x3b4; peak temperature of &#x2212;20&#xb0; C. or higher, a rubber hardness of from 63 to 75, and a tan &#x3b4; at 70&#xb0; C. of from 0.15 to 0.45.

Rubber composition and pneumatic tire

Provided is a pneumatic tire ensuring conductivity while being reduced in weight, and having good fuel efficiency and handling stability. The tire includes a sidewall and a carcass, the sidewall including a laminate of two or more rubber layers including an inner sidewall layer () located closest to the carcass, and an outer sidewall layer () constituting an outer surface of the tire; the layer () including a rubber composition for (); the layer () including a rubber composition for (); the carcass including a carcass cord topped with a rubber composition for a carcass cord topping (); the sidewall having a thickness of 3.0 mm or less; the layer () having a thickness of 0.2-1.0 mm; the composition for () having a volume resistivity of 5.0&#xd7;10&#x3a9;&#xb7;cm or less; the compositions for () and for (), and the compositions for () and for () satisfying specific relations.

An object of the present invention is to provide a rubber composition for tire which has less performance change with respect to a temperature change at a high temperature region and has less performance change with respect to a road surface change from a wet road surface to a dry road surface, and a tire which has a tire member composed of the rubber composition for tire. The rubber composition for tire of the present invention is a rubber composition for tire in which a complex modulus G*and a complex modulus G*satisfy the following formula (1): G*/G*&#x3e;0.85, an elongation at break EBand a loss tangent tan&#x3b4;is not less than 0.12. The present invention also refers to a tire which has a tire member composed of the rubber composition for tire.

Rubber composition for tire and tire

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 improving wet-grip performance and its temperature dependence while ensuring good fuel economy, and a pneumatic tire including the composition. The composition includes, per 100% by mass of a rubber component: 5-55% by mass of an aromatic vinyl compound/conjugated diene compound copolymer (A) having an aromatic vinyl compound content of at least 5% by mass but less than 15% by mass and a vinyl bond content in a conjugated diene compound moiety of 10-70 mol %; and 5-75% by mass of an aromatic vinyl compound/conjugated diene compound copolymer (B) having an aromatic vinyl compound content of at least 15% by mass but less than 30% by mass and a vinyl bond content in a conjugated diene compound moiety of 10-70 mol %, and also includes, per 100 parts by mass of the rubber component, 10-150 parts by mass of a silica having a NSA of 40-400 m/g.

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 achieving balanced improvements in fuel economy, wet-grip performance, abrasion resistance, and handling stability, and a pneumatic tire including the composition. The rubber composition includes a rubber component including at least 95% by mass of conjugated diene polymers having a Tg of &#x2212;75-0&#xb0; C. and a Mw of 1.5&#xd7;10-1.5&#xd7;10, the rubber component (100% by mass) including 5-65% by mass of SBR (A) having a styrene content of at least 5% by mass but less than 15% by mass and a vinyl bond content of 10-70 mol %, and 20-75% by mass of SBR (B) having a styrene content of at least 15% by mass but less than 30% by mass and a vinyl bond content of 10-70 mol %, the composition including, per 100 parts by mass of the rubber component, 1-30 parts by mass of a low-molecular-weight conjugated diene polymer having a Tg of &#x2212;75-0&#xb0; C. and a Mw of at least 1.0&#xd7;10but less than 1.5&#xd7;10, and 10-150 parts by mass of silica having a NSA of 40-400 m/g, the composition having a tan &#x3b4; peak temperature of at least &#x2212;20&#xb0; C.

The present invention provides a tire rubber composition which improves in fuel economy, processability, adhesion, and rubber strength in a balanced manner, and a pneumatic tire. The tire rubber composition includes: a rubber component; a plasticizer (a); and at least one of a resin and a plasticizer (b), the resin being at least one selected from the group consisting of aromatic petroleum resins, terpenic resins, and rosin resins. The plasticizer (a) has a glass transition point of &#x2212;50&#xb0; C. or lower. The resin and the plasticizer (b) each have a glass transition point of &#x2212;40&#xb0; C. to 20&#xb0; C. The tire rubber composition includes, for each 100 parts by mass of the rubber component, 1 to 30 parts by mass of the plasticizer (a) and 1 to 30 parts by mass in total of the at least one of the resin and the plasticizer (b).

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Kobe, Japan

Daisuke Sato