Bridgestone Corporation

Kazuo Yagawa

Junichi Yamagishi

Takatsugu Hashimoto

Naohiro Sasaka

Kazuo Hachiya

Keizo Akutagawa

Makoto Tanaka

Kazuo Hayashi

Shigeo Kimura

Shizuo Iwasaki

Naofumi Ezawa

Satoshi Takezawa

Yukitoshi Ajiro

Rubber composition for tire tread and pneumatic tire using said rubber composition

A pneumatic radial tire comprises a tread portion having a two-layer structure of a cap rubber layer disposed outward in the radial direction and a base rubber layer disposed inward in the radial direction, in which an outer surface of said base rubber layer in the radial direction being existent in a position corresponding to not less than 20% of a depth of a main groove formed in the tread portion outward from a bottom of the main groove in the radial direction, and the base rubber layer being compounded with a recrosslinking inhibition assistant and/or an inorganic compound powder.

Pneumatic radical tire having cap base tread

There is disclosed a rubber composition for a tire tread Which comprises 100 parts by weight of (A) a rubber component comprising a diene-based synthetic rubber or a mixture of a diene-based synthetic rubber and natural rubber and containing at least 20% by weight of a styrene-butadiene rubber; 5 to 50 parts by weight of (B) aluminum hydroxide powders; and at least 5 parts by weight of (C) silica powders, wherein the total amount of the components (B) and (C) is in the range of 40 to 80 parts by weight; and optionally chemical agents such as vulcanizing agents, vulcanization accelerators and antioxidants, and also is disclosed a pneumatic tire in which the above rubber composition is used as the tread rubber. The above rubber composition, when made into a tire tread, can maintain favorable low fuel consumption properties and low wear resistance, and besides can impart the tire with greatly improved gripping properties on wet road surfaces particularly at a low temperature. Moreover, the pneumatic tire made from the above rubber composition can exert excellent effect of maintaining a high maneuverability from the initial stage of running to and after the middle stage thereof.

Rubber composition for tire tread and pneumatic tire using same

A pneumatic tire comprising a tread portion formed by using a rubber composition which comprises: a rubber component comprising 50 parts by weight or more of SBR in 100 parts by weight of the rubber component; optionally, 5 to 40 parts by weight of aluminum hydroxide per 100 parts of the rubber component; per 100 parts by weight of the rubber component, 20 parts by weight or more of a softener which comprises 5 to 55 parts by weight of a specific resin softener having a softening point of 35 to 150&deg; C.; and per 100 parts by weight of the rubber component, 0.2 to 10.0 parts by weight of a specific vulcanization accelerator of a dithiophosphoric acid compound or a specific vulcanization accelerator of a benzothiazole compound. The pneumatic tire exhibits excellent stability and controllability on wet roads or a combination of excellent stability and controllability on wet roads and excellent comfort of ride even when a vehicle is vibrating throughout the life of the pneumatic tire.

Pneumatic tire with tread formed with a rubber compound containing a rubber component, a softener and a benzothiazole compound type vulcanization accelerator

In a flame-retardant rubber tire comprising an outer rubber body portion consisting essentially of a tread rubber layer, a sidewall rubber layer extending inward from each side edge of the tread rubber layer toward the vicinity of a bead portion in radial direction and a rubber chafer layer arranged in the vicinity of the bead portion, a flame-retardant rubber composition having an oxygen index of not less than 19.8 but not more than 27.5 is disposed so as to amount at least 20% by weight of the tread rubber layer. Such rubber tires are used in electric vehicles, automobiles, airplanes and the like and have excellent self-extinguishing property and flame-delaying property without damaging other rubber properties.

Flame-retardant rubber tires

A flame-retardant rubber composition has an oxygen index of 19.8-27.5 and comprises not more than 24% by weight of red phosphorus as a flame retardant based on the rubber composition and a nitrile group-containing elastomer as a flame-retardant polymer component as a part of rubber ingredients constituting the rubber composition. Such flame-retardant rubber compositions are very useful in applications such as industrial goods, tire and the like strongly requiring the fire preventing function.

Flame-retardant rubber compositions

Growing community of inventors

Urawa, Japan

Kazuo Yagawa