Nok Corporation

Hideyuki Tokumitsu

Osamu Kobayashi

Masashi Kudo

Shigeyuki Ono

Hironori Minagawa

Takashi Ohta

Takuya Yamanaka

A hydrogenated nitrite rubber composition for providing a cross-linked product having a 20% modulus of 10 MPa or more and a thermal conductivity of 0.4 W/m&#xb7;K or more at 25&#xb0; C. The hydrogenated nitrile rubber composition includes 100 parts by weight of hydrogenated nitrile rubber having a bound acrylonitrile content of 40% or more, a polymer Mooney viscosity ML(100&#xb0; C.) of 75 or less (median) as determined according to JIS K-6395, an iodine value of 23 or less (median), and at least 110 parts by weight in sum total of carbon black as a filler and other gas shielding filler. The hydrogenated nitrile rubber composition can effectively be used as a molding material for sliding applications or for a static sealing members for highly permeable gases. The hydrogenated nitrile rubber composition has a distinguishing carbon dioxide gas shieldability, heat resistance, and wear characteristics.

Hydrogenated nitrile rubber composition

A molding material for use with carbon dioxde, which comprises chlorinated polyethylene having a chlorine content of 25&#x2013;47% by weight or a blend of chlorinated polyethylene with vinyl chloride-based resin, can be used as a suitable material for sealing materials in carbon dioxide-contacting apparatuses using carbon dioxide as a refrigerant. Addition of a specific silane coupling agent to the molding material can effectively prevent vulcanization moldings from blister generation.

Molding material for use with carbon dioxide

A high pressure shaft seal (A) for use in a refrigerating machine wherein carbon dioxide is used as a refrigerant in lieu of 'Freon'. The seal has a sealing lip (A) made of a non-elastomeric polymer material such as nylon that has a small gas permeability coefficient, a region of the sealing lip brought into contact with a shaft to be sealed being lined with a low friction lining (A) of polytetrafluoroethylene. The gas barrier sealing lip (A) of nylon serves to effectively block permeation of carbon dioxide gas under an extremely high pressure of from about 4 MPa to about 12 MPa. The sealing lip (A) of nylon has a relatively high rigidity but is nevertheless able to resiliently undergo elastic deformation when such a high pressure is applied, to thereby resiliently follow any shaft run-out to exhibit sufficient dynamic and static sealing functions.

Lip-type high pressure seal

A molding material for use with carbon dioxide, which comprises chlorinated polyethylene having a chlorine content of 25-47% by weight or a blend of chlorinated polyethylene with vinyl chloride-based resin, can be used as a suitable material for sealing materials in carbon dioxide-contacting apparatuses using carbon dioxide as a refrigerant. Addition of a specific silane coupling agent to the molding material can effectively prevent vulcanization moldings from blister generation.

Molding material for use with carbon dioxide refrigerant

An object of the present invention is to provide a molding composition having an excellent properties to seal carbon dioxide. The composition is made of fluoro thermoplastic elastomer having a reinforcing filler such as carbon black or white carbon having a particle diameter of not more than 100 nm. The composition can be used as a sealing materials such as O-ring, oil seal, gasket, hose, tube or diaphragm for sealing carbon dioxide.

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Tsukuba, Japan

Hideyuki Tokumitsu