Bridgestone Corporation

Eiji Takiguchi

Kazuaki Yuto

Toru Oniki

Kojiro Yamaguchi

Seiichiro Iwafune

Toshiro Iwata

Masashi Ohara

Toshiharu Kikutsugi

A low noise level tire includes a carcass composed of at least one ply toroidally extending between a pair of bead cores, and a tread arranged radially outwardly of the carcass and composed of an outer cap rubber layer and an inner base rubber layer. The cap rubber layer is made of a rubber having a dynamic storage modulus of not less than 1.0&times;10,dyn/cm,and not more than 2.0&times;10,dyn/cm,and a loss tangent more than 0.15 and not more than 0.35. The base rubber layer is made of a rubber having a dynamic storage modulus of not less than 1.2&times;10,dyn/cm,and not more than 2.2&times;10,dyn/cm,and a rate of foaming of not less than 5% and not more than 50%.

Low noise level tire

A pneumatic tire having excellent tire performances in winter and summer seasons comprises a tread, a part of which is comprised of an expanded rubber in a volume corresponding to at least 10% of the total volume of the tread at its surface. This expanded rubber contains particular rubber component and particular high reinforcing carbon black and oil, and has particular number of closed cells having a specified cell diameter to the total number of closed cells. Furthermore, a rubber reinforcing layer is arranged near to the tread shoulder.

Pneumatic tire having expanded outer tread rubber layer

A tread rubber composition having a high gripping property for use in high-speed running is disclosed, which comprises a diene rubber inclusive of at least one styrene-butadiene rubber, 70-150 parts by weight of carbon black and 30-120 parts by weight of a softening agent per 100 parts by weight of rubber component and has particular crosslinking structure, loss tangent (at 30.degree. C.) and peak temperature at this loss tangent as properties after vulcanization.

Tire with defined inner and outer tread rubber compositions

Disclosed herein is a low fuel consumption pneumatic tire with all weather running performances, which tire uses as a tread a vulcanizable rubber composition obtained by adding 30-80% by weight of carbon black having an iodine adsorption value of not less than 70 mg/g and a dibutylphthalate (DBP) adsorption of not less than 90 ml/100 g, and a low temperature plasticizing ester and/or naphthenic or paraffinic solftener in an amount 2 to 50% by weight relative to said carbon black into 100 parts by weight of a rubber component composed of 100 to 25 parts by weight of at least one kind of a first diene rubber containing 0 to 30% of styrene and 25 to 95% of vinyl bonds in the butadiene unit and 0 to 75 parts by weight of at least one kind of a second diene rubber which is different in kind from the above first diene rubber.

Low fuel consumption tire with all weather performances

A pneumatic tire having a low fuel consumption and all-weather running performances is disclosed, which comprises a tread composed of a rubber composition containing 30-80 parts by weight of carbon black having IA of not less than 70 mg/g and DBP absorption of not less than 90 ml/100 g, based on 100 parts by weight of a rubber blend consisting of 97-10 parts by weight of at least one diene rubber having a content of bound styrene of 0-30% and a content of vinyl bond in butadiene unit of 25-95%, 3-30 parts by weight of butyl rubber and/or halogenated butyl rubber, and 0-87 parts by weight of the other diene rubber.

Pneumatic tire having all-weather running performances

A pneumatic tire suitable for running on snow and ice roads is improved by providing tread portion composed of a rubber composition comprising 100 parts by weight of a blend rubber consisting of (A) 50 to 90 parts by weight of at least one rubber selected from the group consisting of natural rubber, polyisoprene rubber, butadiene-styrene copolymer rubber, polybutadiene rubber, butyl rubber and halogenated butyl rubber and (B) 10 to 50 parts by weight of a diene type rubber containing 0 to 25% of styrene group (x) and 0 to 50% of 1,2 vinyl bond group (y), (x) and (y) satisfying the following relationship: ##EQU1## mixed with 40 to 100 parts by weight of carbon black and 0 to 60 parts by weight of a softener and vulcanized.

Pneumatic tire suitable for running on snow and ice roads

Disclosed herein is a pneumatic tire suitable for running on snow and ice roads, a tread portion of which consists of a rubber composition comprising 0-60 parts by weight of a petroleum softener and 5--35 parts by weight of a low-temperature ester type plasticizer based on 100 parts by weight of a rubber blend consisting of 30-95 parts by weight of at least one rubber selected from the group consisting of natural rubber, polyisoprene rubber and styrene-butadiene copolymer rubber, 0-50 parts by weight of polybutadiene rubber, and 5-30 parts by weight of butyl rubber or halogenated butyl rubber.

Growing community of inventors

Higashiyamato, Japan

Eiji Takiguchi