Tokai Rubber Industries, Ltd.

Koji Senda

Ayumu Ikemoto

Eiichi Daikai

Kazutaka Katayama

Hiroyoshi Mori

Hidehito Ikeda

Tetsuji Narasaki

Chiaki Yuzuriha

A sulfur vulcanizing system rubber composition comprises EPDM, zinc as a vulcanization accelerator activator, at least one thiazole type vulcanization accelerator serving to control the dissolution of zinc from the composition, and at least one ultra-accelerator of the thiuram or dithiocarbamate type, these accelerators being preferably combined under specified quantitative limitations. The hose using this rubber composition is particularly suitable for use in a cooling system for an automobile engine, since the dissolution of zinc into a coolant is prevented, thereby preventing the formation of any zinc compound causing the blocking of the hose, or the leakage of the coolant through the seal between the hose and any pipe connected therewith.

Rubber compositions and hoses

A rubber composition which can achieve superior adhesion force between it and a material to be adhered without a coating of an adhesive. The rubber composition includes the following components (A) to (D): (A) a rubber composed of at least one of an ethylene-propylene-diene terpolymer and an ethylene-propylene copolymer, (B) a peroxide vulcanizing agent, (C) a resorcinol-based compound, and (D) a melamine resin.

Rubber composition

A packing structure has a core element of a material having a high fluid impermeability, and a thin coated rubber layer formed thereon to cover at least its sealing surface and having a glass transition temperature which is lower than the lowest temperature allowable for the packing structure. It shows a high sealing property even at a low temperature and a high fluid impermeability when used for sealing e.g. a pipeline for conveying fuel in a motor vehicle.

Packing structure

A refrigerant hose for an air conditioner has an inner wall layer formed of a laminate of an inner resin layer and an outer rubber layer bonded by its vulcanization to the resin layer. The rubber layer is of a composition comprising butyl rubber, an adhesive material based on resorcinol and a vulcanizing agent based on an alkylphenol-formaldehyde resin, and having a bromine content of at least 0.5% by weight. The hose having the inner wall layer surrounded by a reinforcing layer and an outer wall layer exhibits a high adhesive strength even at an elevated temperature between its refrigerant-impermeable resin layer and its water-impermeable rubber layer.

Rubber compositions, rubber-resin laminates and fluid-impermeable hoses

Check valve

A peroxide cure system rubber composition comprises EPDM having a high iodine value and an appropriate ethylene proportion, and preferably at least quinoline as an antioxidant, and is particularly suitable for use in making a hose in a cooling system for an automobile engine. The hose is highly resistant to hot air aging and cracking, though the composition does not contain zinc.

Growing community of inventors

Niwa-gun, Japan

Koji Senda