The Yokohama Rubber Co., Ltd.

Keisuke Maejima

Makoto Ashiura

Satoshi Mihara

Kazushi Kimura

Yoshihiro Kameda

Takashi Shirokawa

Katsunori Shimizu

Yayoi Akahori

Ayumi Naka

Masaki Satou

Masaki Sato

Takashi Kakubo

A rubber composition for use in a tire tread includes: per 100 parts by weight of diene rubber containing 40 wt % or greater of butadiene rubber, and a styrene butadiene rubber, from 80 to 150 parts by weight of silica having a CTAB specific surface area of 150 to 250 m/g, and a long chain alkyl group-containing silane compound in an amount of 1 to 10 wt % of the amount of the silica. The rubber composition further includes a styrene component in the diene rubber being from 15 to 20 wt %, and a vinyl component in the diene rubber being from 18 to 28 wt %; and an average glass transition temperature of the diene rubber is &#x2212;55&#xb0; C. or lower.

Rubber composition for use in tire tread

A rubber composition for tires of the present technology contains a diene rubber, silica, and a predetermined alkyltrialkoxysilane; the diene rubber containing a butadiene rubber and a particular conjugated diene rubber, a content of the butadiene rubber in the diene rubber being 20 mass % or greater and a content of the particular conjugated diene rubber in the diene rubber being from 30 to 80 mass %; an average glass transition temperature of the diene rubber being from &#x2212;65 to &#x2212;45&#xb0; C.; the particular conjugated diene rubber being a conjugated diene rubber produced by a particular production method and having predetermined ranges of aromatic vinyl unit content, vinyl bond content, and weight average molecular weight.

Rubber composition for tires and pneumatic tire

A studded tire includes stud pins embedded in a road contact surface of a tread portion; 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 m/g; a CTAB specific surface area of the silica being from 80 to 190 m/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&#xb7;mmand not greater than 850 MPa&#xb7;mm.

Stud tire

The present technology provides a rubber composition for a tire with which it is possible to produce a tire having excellent on-ice performance and excellent wear resistance, and a studless winter tire using the rubber composition. The rubber composition for a tire of the present technology is a rubber composition for a tire comprising: 100 parts by mass of a diene rubber (A); from 30 to 100 parts by mass of carbon black and/or a white filler (B); and from 0.3 to 30 parts by mass of a cured product (C) prepared by curing a crosslinkable oligomer or polymer (c1) incompatible with the diene rubber (A); a JIS A hardness of the cured product (C) being from 3 to 45.

Rubber composition for tire and studless winter tire

A rubber composition for use in tire treads comprises a diene rubber including not less than 40% by weight of a modified conjugated diene polymer rubber and, per 100 parts by weight of the diene rubber, from 66 to 110 parts by weight of a filler. The filler comprises not less than 50% by weight of silica. The modified conjugated diene polymer rubber is obtained by copolymerizing a conjugated diene monomer unit and an aromatic vinyl monomer unit in a hydrocarbon solvent using an organic active metal compound as an initiator. A resulting active conjugated diene polymer chain thereof has a terminal modified group, obtained by reacting at least one type of compound having a functional group that is reactable with the active terminal of the polymer chain. Moreover, the terminal modified group has a functional group that interacts with the silica.

Rubber composition for use in tire treads

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 &#x3bc;m average particle diameter.

Tire rubber composition and studless tire

A rubber composition comprises a diene rubber including not less than 25% by weight of a modified conjugated diene polymer rubber and, per 100 parts by weight of the diene rubber, from 25 to 65 parts by weight of a filler, the filler comprising not less than 50% by weight of silica. The silica has a DBP absorption number of 190 to 250 ml/100 g, an NSA of 194 to 225 m/g, and a CTAB of 185 to 215 m/g. A ratio of the NSA to the CTAB is from 0.9 to 1.4. The modified conjugated diene polymer rubber has a terminal modified group including a functional group that interacts with the silica. In the modified conjugated diene polymer rubber, aromatic vinyl unit content is from 38% to 48% by weight, vinyl unit content is from 20% to 35%, and weight-average molecular weight is from 600,000 to 1,000,000.

Rubber composition for tire tread

The purpose of the present invention is to provide a rubber composition with which it is possible to produce a tire that retains wear resistance and has excellent frictional force on ice, and a pneumatic tire using the rubber composition. The rubber composition of the present invention is a rubber composition comprising a diene rubber, carbon black and/or a white filler, and a master batch prepared by premixing a non-diene rubber and an organic peroxide, wherein a total content of carbon black and white filler is from 20 to 70 parts by mass per 100 parts by mass of diene rubber and a content of the non-diene rubber in the master batch is from 3 to 30 parts by mass per 100 parts by mass of the diene rubber.

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Hiratsuka, Japan

Keisuke Maejima