Sumitomo Rubber Industries Limited

Other

Sumitomo Electric Industries, Limited

Sumitomo (sei) Steel Wire Corp.

Nippon Steel Sumitomo Metal Corporation

Sumitomo Electric Tochigi Co., Ltd.

Yasuo Sakai

Shinichi Miyazaki

Kazumi Yamazaki

Osamu Toda

Kenichi Okamoto

Keisuke Aramaki

Junichi Kodama

Yuichi Sano

Kazuhiko Saito

A rubber-cord complex having an improved wet heat adhesive property between a rubber and a cord comprising a drawn plated wire, and including a metal cord comprising a drawn plated wire prepared by providing a brass plated layer on the surface of an element wire and drawing the resulting plated wire, and a rubber vulcanized and bonded to the cord, wherein in a wet heat deterioration state of the drawn plated wire after being subjected to the vulcanization to bond the rubber thereto and further held under an atmosphere having a temperature of 50 to 100&#xb0; C. and a humidity of 60 to 100% for one hour to 20 days, the average grain size of crystal grains present in the brass plated layer is not more than 50 nm, and the grain boundary of the crystal grains has a fractal dimension of 1.001 to 1.500.

Metal cord, rubber-cord complex and pneumatic tire using the same

Rubber-cord complexhaving improved wet heat adhesive property between rubber and cord. The rubber-cord complex includes cordcomprising drawn plated wireprepared by providing brass plated layerE on surface of element wireand drawing the resulting plated wire and rubbervulcanized and bonded to cord. The rubber-cord complexhas adhesion reaction layer(formed by cross-linking sulfur and copper) between rubberand brass plated layerE. Adhesion reaction layerhas average thickness of 50-1,000 nm. Interface S between adhesion reaction layerand the rubber has a fractal dimension of 1.001-1.300 in a wet heat deterioration state after being subjected to vulcanization to bond rubberthereto and being held at a temperature of 50-100&#xb0; C. and a humidity of 60-100% for one hour to 20 days.

A rubber product-reinforcing metallic cord is provided which comprises three to five metallic filaments, which shows a high degree of penetration of rubber without reducing compressive rigidity, and which can be manufactured at low facility and production costs. A rubber product-reinforcing metallic cordis formed by twisting together a pre-strandcomprising a first metallic filamentand a second metallic filamenthelically wrapped around the first filament, and a fifth metallic filament(or) with a twist pitch P. The metallic cordmay be formed by twisting together two of such pre-strands, or by twisting together two of such pre-strands and the fifth metallic filament.

Rubber product-reinforcing metallic cord and method for manufacturing such a cord

A pneumatic tire comprises a cord-reinforced layer such as carcass, belt, bead reinforcing layer which is made of metallic cords, each metallic cord is made up of six to twelve metallic filaments whose diameter is in a range of from 0.15 to 0.45 mm, the metallic filaments include waved filaments and unwaved filaments, each waved filament is two-dimensionally waved at a wave pitch and wave height before twisted, the wave pitch is in a range of from 5.0 to 35.0 times the diameter of the filament, and the wave height is in a range of from 0.2 to 4.0 times the diameter of the filament, and the metallic filaments are twisted together into the cord at a twist pitch of from 10 to 40 mm so that the two-dimensionally waved filaments are each subjected to a certain rotation around its axial.

Pneumatic tire

A method of manufacturing a rubber reinforcing steel cord is provided, wherein the steel cord has a steel wire plated with metal containing copper and having on its surface an oil layer containing a cobalt compound, and includes an application step in which the oil containing a cobalt compound is applied to the steel wire or a steel cord plated with metal containing copper, and a step of twisting the steel wires.

Rubber reinforcing steel cord, manufacturing method of rubber reinforcing steel cord and pneumatic tire

A pneumatic tire comprises a tread reinforcing belt made of metallic cords, each of the metallic cords is made up of six to twelve metallic filaments whose diameter is not less than 0.15 mm but less than 0.25 mm, the six to twelve metallic filaments are grouped into a plurality of bunches each including two to four filaments, the filaments of each bunch are twisted together at a first twisting pitch, the bunches are twisted together into the cord at a final twist pitch Pc of from 10 to 40 mm, the first twisting pitch is more than the final twist pitch, and the bunches each include at least one waved filament which is two-dimensionally waved at wave pitches Pw in a range of from 5 to 30 times the diameter (d) of the filament and a wave height (h) in a range of from 0.2 to 3.0 times the diameter (d).

A steel cord is formed by compactly twisting steel filaments together, the steel filaments including a plurality of zigzag filaments and optionally a nonzigzag filament, the zigzag filament being zigzaged two-dimensionally and made up of straight segments each extending between the zigzag peak points, the nonzigzag filament being straight. In case the cord is composed of only the zigzag filaments, the zigzag filaments include at least two kinds of zigzag filaments having different zigzag pitch lengths. In case the cord is composed of both the zigzag filaments and nonzigzag filaments, some of the zigzag and nonzigzag filaments are first loosely twisted together into a bunch, and then a plurality of bunches are twisted together into the cord. In any case, the zigzag pitch length and zigzag wave height of each zigzag filament are substantially constant along the length thereof. A Tire comprises a reinforcing layer such as a tread reinforcing belt layer, carcass, bead reinforcing layer and the like made of the above-mentioned steel cords.

Growing community of inventors

Utsunomiya, Japan

Yasuo Sakai