Nok Corporation

Nissan Motor Company Limited

Atsushi Yokota

Toshihiro Higashira

Isao Watanabe

Kuniaki Miyake

Hiroki Uehara

Yoshifumi Kojima

Naoki Matsumoto

Tatsuya Osone

Koji Tsukamoto

Taichi Kano

Toshihiro Mukaida

Jun Furuichi

Yasuaki Kitajima

Yoichi Moritani

Hitoshi Okabe

Yuuzo Akasaka

The invention provides a clutch seal which can enhance a durability of a membrane portion which is a constituting part of a seal and is constructed by a rubber-like elastic body, and can inhibit a working fluid from standing in a concave surface of the membrane portion. The clutch seal of the invention is an annular seal interposed between a clutch plate in a dry clutch and a piston pressing the clutch plate, has a middle ring fixed to the piston between an outer ring and an inner ring which are fixed to a clutch housing, and has membrane portions constructed by a rubber-like elastic body respectively between the outer ring and the middle ring and between the inner ring and the middle ring, wherein the middle ring is arranged at an intermediate position of a stroke in an initial shape of the membrane portion.

Clutch seal

An NBR composition including an NBR polymer, a vulcanizing agent, a vulcanizing accelerator, and carbon black, wherein the carbon black includes a combination of MT carbon black and carbon black having an iodine absorption number of 20 mg/g or less and a DBP absorption number of 40 cm/100 g or more, and has a total added amount of 110 to 250 parts by weight based on 100 parts by weight of the NBR polymer, and the amount of the MT carbon black is larger than that of the carbon black having an iodine absorption number of 20 mg/g or less and a DBP absorption number of 40 cm/100 g or more and the amount of the carbon black having an iodine absorption number of 20 mg/g or less and a DBP absorption number of 40 cm/100 g or more is 10 to 70 parts by weight based on 100 parts by weight of the NBR polymer, and a metal laminate obtained by laminating the NBR composition.

NBR composition and rubber-metal laminate

Provided is a fluororubber composition which does not deteriorate workability during roll kneading, does not cause foaming during crosslinking and molding, and is capable of giving a crosslinked molded article which exhibits desired hardness and sealing property without using a reinforcing inorganic filler such as carbon black and silica. The fluororubber composition includes, relative to 100 parts by weight of a vinylidene fluoride-copolymerized, fluorine-containing elastomer copolymer having a glass transition temperature and a melting point, no reinforcing inorganic filler, 5 to 100 parts by weight of a PTFE filler, 0.5 to 10 parts by weight of a polyol crosslinking agent, 1 to 15 parts by weight of magnesium oxide, and 0.1 to 2 parts by weight of hydrotalcite. Preferably, 0.1 to 10 parts by weight of a quaternary onium salt crosslinking accelerator is further included.

Fluororubber composition

The purpose of the present invention is to provide a gasket material that is capable of preventing corrosion caused by sulfur element, can be used as a seal part for a product that is easily damaged by corrosion, such as an electronic part, and is capable of forming a tight seal under low surface pressure with a material having low rigidity and inadequate reliability such as to have a blowhole, and that can prevent reduction in bolt axial load without producing plastic flow (setting) under pressure. The purpose is achieved by a gasket material in which a foamed rubber layer having a closed cell structure is formed, via an adhesive layer, on at least one side of a metal plate, wherein the foamed rubber layer comprises a carboxyl group-modified nitrile rubber, the expansion ratio of the foamed rubber layer is 2.0 to 3.0, and the foamed rubber layer is crosslinked with an epoxy compound.

Gasket material

A coating agent, which comprises a cellulose derivative, an isocyanate group-containing 1,2-polybutadiene, a synthetic wax having a softening point of 100&#xb0;-150&#xb0; C., a fatty acid amide having a softening point of 60&#xb0;-170&#xb0; C., and graphite, can satisfy desired performances, when applied to rubbery elastomers, etc. such as prevention of sticking, adhesion and blocking, and improvement of abrasion resistance, and also can serve as a surface-treating agent for vulcanized rubber without peeling of coating films due to adhesion under high-temperature compression or friction-abrasion under high specific pressure.

Coating agent

A fluororubber-metal laminate sheet, which comprises a metallic sheet and a vulcanized fluorocarbon layer, provided on the metallic sheet by applying thereto a fluororubber composition comprising (A) 100 parts by weight of a polyol-vulcanizable fluororubber, (B) 10-50 parts by weight of amorphous graphite, (C) 1-15 parts by weight of a phenol resin, (D) 1-4 parts by weight of a silane coupling agent, (E) 0.5-8 parts by weight of a polyol-based vulcanizing agent, and (F) 0.5-6 parts by weight of a vulcanizing accelerator, followed by vulcanization of the fluororubber composition to form laminate, where the metallic sheet is free from either a chromating treatment or a chromating substitute treatment, is distinguished in characteristics such as sealability, compression resistance, air-heated aging resistance, anti-freezing liquid resistance, oil resistance, sticking resistance, abrasion resistance, etc.

Fluororubber-metal laminate sheet

A hydrogenated nitrile rubber-metal laminate having distinguished heat and rubber bulging resistances at elevated temperatures and surface pressures, which comprises a metallic sheet subjected to a hexavalent Cr ions-free chemical conversion treatment, a defatting treatment, a surface-roughening treatment, a primer treatment, or a combination of the treatment, and an adhesive layer and a rubber layer successively laid on one or both surfaces of the metallic sheet, wherein the rubber layer is a vulcanizate of a hydrogenated nitrile rubber compound comprising 100 parts by weight of a hydrogenated nitrile rubber, 50-250 parts by weight of an inorganic filler containing not more than 20% by volume, on the basis of total compound, of a non-reinforcing inorganic filler having an average particle size of not more than 5 &#x3bc;m, 4-20 parts by weight of an organic peroxide, and preferably furthermore 2-10 parts by weight of N,N'-phenylene dimaleimide.

Growing community of inventors

Kanagawa, Japan

Atsushi Yokota