The Yokohama Rubber Co., Ltd.

Yasuhiro Ishikawa

Osamu Ozawa

Ryotaro Suefuji

Takeshi Hotaka

Shinji Kawakami

Shuji Takahashi

Sadakazu Takei

Hiroyuki Kaido

Hiroshi Hirakawa

Makoto Misawa

Takao Muraki

Masashi Kida

Kazuhiro Yamada

Hiroyuki Kaidoo

Takekazu Inoue

A run-flat tire-wheel assembly having, in an inside cavity of the tire/rim, a run-flat support formed by a ring-shaped metal shell and rubber elastic members or a ring-shaped metal shell and rubber elastic members composed of a rubber composition containing 100 parts by weight of a peroxide cross-linkable rubber and 1 to 30 parts by weight of a peroxide cross-linking agent, wherein the contact surfaces of the ring-shaped metal shell with the rubber elastic members are subjected to an electrolytic polymerization with 6-mono- or di-allylamino-1,3,5-triazine-2,4-dithiol or its mono- or di-salt, whereby the bondability between the ring-shaped metal shell and rubber elastic members is improved.

Tire-wheel assembly

A run flat tire wheel assembly having a flat run support formed by a ring-shaped metal shell and rubbery elastic members in a tire rim cavity, said tire wheel assembly improving bondability between the ring-shaped metal shell and rubbery elastic members by making said rubbery elastic member from a rubber composition including 100 parts by weight of a diene-based rubber, 40 to 90 parts by weight of carbon black, 3 to 8 parts by weight of sulfur, 0.1 to 1 part by weight of an organic acid cobalt salt in terms of content of cobalt element, 0.1 to 3 parts by weight of a phenylene-diamine-based antiaging agent, and 1 to 6 parts by weight of a resol-type alkylphenol resin.

Tire wheel assembly

A rubber composition for a tire tread comprising (i) 100 parts by weight of a rubber component comprising (a) natural rubber and (b) a styrene-butadiene copolymer rubber having a vinyl content in the butadiene portion of 35 to 80% by weight and a styrene content of 10 to 40% by weight wherein the total amount these rubbers is at least 80 by weight of the total rubber component and wherein the amount of the styrene-butadiene copolymer rubber, is 20 to 60% by weight of the total rubber component, (ii) 20 to 70 parts by weight of silica and (iii) 20 to 70 parts by weight of carbon black.

Rubber composition for tire tread

Pneumatic radial tires are disclosed which are comprised of two or more belt plies reinforced respectively with an aramid fiber cord and a steel wire cord. Both cords are coated with one and the same rubber composition made up of a selected class of starting rubbers, sulfer, resorcinol and/or its precondensate, hexamethoxymethylmelamine and a selected class of cobalt compounds derived from organic acids. The belt plies excel in water-resistant adhesion and heat resistance and thus have freedom from ply separation, contributing to a radial tire of improved durability.

Pneumatic radial tire having belt reinforcements

Rubber compositions are disclosed which are highly calenderable and adhesively strong for coating on steel cords to be assembled in radial tires. Such coating characteristics are obtained by the use of specified amounts of a selected type of saturated aliphatic alcohol combined with selected base rubbers.

Rubber compositions for steel tires

Rubber compositions suitable for tire treads are disclosed. Starting rubbers made up of at least one SBR of -20.degree. C. to -40.degree. C. in Tg and at least one SBR of lower than -45.degree. C. in Tg are blended with specified amounts of carbon blacks having a N.sub.2 SA of more than 120 m.sup.2 /g and of softeners having a VGC of 0.90 to 0.98, whereby the compositions are provided with a storage shear modulus of less than 500 MPa at -30.degree. C. The compositions are excellent in friction performance, abrasion resistance and low-temperature resistance.

Rubber compositions for tire treads

A rubber composition comprising, in specific mixing ratios, rubber material consisting mainly of natural rubber and/or synthetic polyisoprene rubber, a cobalt salt of rosin, carbon black having specific iodine adsorbability and dibutyl phthalate absorbability, and sulphur.

Rubber compositions comprising (1) polyisoprene (2) cobalt salt of rosin

A composite comprising a steel cords-covering rubber composition and a rubber composition which is contiguous thereto and contains a thiazole type vulcanization accelerator, at least one of these rubber compositions containing a m-cresol resin whereby they can be cured without decreasing the resulting strength of bond therebetween even after they have been left uncured in contact with each other for a considerable time.

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Hiratsuka, Japan

Yasuhiro Ishikawa