The Yokohama Rubber Co., Ltd.

Ryotaro Suefuji

Gang Hou

Atsushi Miyajima

Hidehiro Sasakuma

Osamu Ozawa

Yasuhiro Ishikawa

Takeshi Hotaka

A rubber product that includes a cylindrical molded body having a plurality of reinforcing layers coaxially layered between inner and outer layers. In producing/vulcanizing the molded body, a rubber product including a cylindrical portion, each of multiple reinforcing layers composed of cord fabrics including a large number of fiber cords aligned and subjected to a predetermined adhesion treatment and coating rubber layers covering both surfaces of the cord fabric, and a bias structure in which the fiber cords of the reinforcing layers extend in an intersecting direction is formed. Each of the cord fabrics has: a tensile strength of ≥4320 N/cm in a cord extension direction and a weight of ≤950 g/m, each of the cord fabrics has a bending hardness of ≤30 g/cm after the predetermined adhesion treatment, and each of the coating rubber layers has a layer thickness of ≥0.2 mm and ≤1 mm.

Rubber product and method of producing same

The present technology provides a reinforcing layer for a rubber product. A reinforcing layer embedded in a conveyor belt is composed of a plurality of steel cords embedded so as to extend in the belt longitudinal direction side by side in parallel. The outer diameter of the steel cords is not less than 0.35 mm and not greater than 6.0 mm, and the side-by-side pitch is greater than 0.35 mm and not greater than 7.0 mm.

Reinforcing layer for rubber product

A steel cord has a stranded structure comprising a plurality of sheath strands intertwined around the outer circumferential surface of a core strand; and a filament having a linear mass density of at least 560 dtex and not more than 2,200 dtex wrapped in a spiral around the outer circumferential surface of the core strand. The steel cord is embedded in an unvulcanized rubber member to mold a molded rubber article, which is then vulcanized.

Steel cord and method of manufacturing rubber product

The present technology provides a conveyor belt. An upper cover rubber and a lower cover rubber are respectively disposed above and below a core layer so as to sandwich the core layer, which core layer is composed of a plurality of steel cords extending side by side in parallel. The outer diameter of the steel cords is not less than 0.35 mm and not greater than 6.0 mm, and the side-by-side pitch P of the steel cords is greater than 0.35 mm and not greater than 7.0 mm. The steel cords are embedded extending in the longitudinal direction of the conveyor belt.

Conveyor belt

A coating rubber composition for a conveyer belt, comprising 15 to 75 parts by mass of carbon black having a nitrogen adsorption specific surface area of 50 m/g or less, 25 to 100 parts by mass of calcium carbonate and 40 parts or less by mass of an oil per 100 parts by mass of blended rubber comprising of natural rubber and at least one of either butadiene rubber or SBR. The above coating rubber composition for conveyer belts can improve not only the peel force which is a criterion of adhesiveness with the canvas cloth but also the power-saving capability of the conveyer belt while maintaining the durability thereof. Further, compounding of silica in an amount of 5 to 20 parts by mass can achieve a sufficient rubber attachability onto the canvas cloth when over-vulcanized, while maintaining the peel force when subjected to normal vulcanization.

Coating rubber composition for conveyer belts

Steel cords have a stranded structure in which a plurality of sheath strands is intertwined around the outer circumferential surface of a core strand. The outer circumferential surface of the core strand is covered by a cushioning material made of nonwoven fabric or a resin film.

The present technology provides a rubber composition containing: a diene-based rubber containing a natural rubber and a butadiene rubber; a carbon black 1; and a carbon black 2. A nitrogen adsorption specific surface area of the carbon black 1 is from 60 to 100 m/g; a dibutyl phthalate oil absorption of the carbon black 1 is 120 cm/100 g or less; a nitrogen adsorption specific surface area of the carbon black 2 is from 20 to 40 m/g; a dibutyl phthalate oil absorption of the carbon black 2 is from 70 to 95 cm/100 g; and a total amount of the carbon black 1 and the carbon black 2 being from 25 to 50 parts by mass per 100 parts by mass of the diene-based rubber.

Rubber composition and conveyor belt using same

A rubber-reinforcing steel cord embedded in a rubber product has a stranded structure including a core strand, and a plurality of sheath strands intertwined around an outer circumferential surface of the core strand; wherein a lubricant is provided between wires that constitute the core strand.

Steel cord and conveyor belt

A conveyor belt includes a core layer disposed between an upper cover rubber layer and a lower cover rubber layer. The core layer is configured from a plurality of steel cords covered by cushioning rubber and arranged in parallel. The rubber that forms the lower cover rubber layer is a low loss rubber that has a loss factor tan&#x3b4; of 0.07 or less at a frequency of 10 Hz, 2% dynamic strain, and temperature of 20&#xb0; C. The maximum thickness of the cushioning rubber is reduced to not more than &#x2153; the nominal diameter of the steel cords.

The present technology provides a rubber composition for a conveyor belt. The rubber composition comprises: a rubber component containing butadiene rubber and/or styrene butadiene rubber, carbon black, sulfur, and a vulcanization accelerator; the glass transition temperature of the butadiene rubber and the styrene butadiene rubber being &#x2212;65&#xb0; C. or lower; the nitrogen adsorption specific surface area of the carbon black being 90 m/g or less; the total content of the butadiene rubber and the styrene butadiene rubber being 50% by mass or greater relative to the content of the rubber component; the content of the carbon black being from 30 to 50 parts by mass per 100 parts by mass of the rubber component; and the mass ratio (sulfur/vulcanization accelerator) of the content of the sulfur to the content of the vulcanization accelerator being 1.5 or less.

Rubber composition for conveyor belt, and conveyor belt

Provided is a rubber-reinforcing steel cord that has superior productivity and is advantageous in reducing weight and improving bending resistance, as well as a conveyor belt that uses the rubber-reinforcing steel cord. A rubber-reinforcing steel cordhaving a 1+6+(6+6) structure formed by twisting individual steel wires, andonce in the same direction, a twist multiple of at least 9 and not greater than 14, and an outer diameter of not greater than 4 mm is used by being embedded in a rubber product.

Rubber-reinforcing steel cord and conveyor belt

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.

Growing community of inventors

Hiratsuka, Japan

Ryotaro Suefuji