A seal rubber composition contains a carboxyl group-containing acrylic rubber, silica, and two or more inorganic fibers, an amount of the silica per 100 parts by weight of the carboxyl group-containing acrylic rubber is 25 to 100 parts by weight, and a total amount of the inorganic fibers per 100 parts by weight of the carboxyl group-containing acrylic rubber is 35 to 100 parts by weight. A sealing member includes a sliding portion composed of a vulcanized product of the seal rubber composition.

The present disclosure provides a high-pressure hydrogen apparatus gas seal member which is excellent in durability and is capable of sufficiently suppressing an occurrence of a blister fracture. A high-pressure hydrogen apparatus gas seal member of the present disclosure is a high-pressure hydrogen apparatus gas seal member made of a crosslinked product of an elastomer composition which comprises an elastomer and fibrous carbon nanostructures having an average length of 100 μm or more and 1000 μm or less, wherein the fibrous carbon nanostructures have a surface fractal dimension of 2.3 or more and 3.0 or less or a radius of gyration of 50 nm or more and 500 nm or less, and further the fibrous carbon nanostructures has an inner diameter of 4.0 nm or less.

Disclosed is a gas seal member for high-pressure hydrogen device with sufficiently reduced occurrence of both swelling destruction and blister destruction. The gas seal member is formed of a cross-linked product of an elastomer composition which comprises an elastomer and fibrous carbon nanostructures, wherein a hydrogen diffusion coefficient D1 of a cross-linked product of an elastomer component including the elastomer and a hydrogen diffusion coefficient D2 of the cross-linked product of the elastomer composition satisfy the relationship 0.7<D2/D1<1.0.

The use of a sealing layer of a composition including at least one polyamide for preparing a multicore structure intended for the transport, distribution or storage of hydrogen, in particular for the distribution or storage of hydrogen, especially for the storage of hydrogen, the sealing layer satisfying a test for contaminants present in the hydrogen and extracted from the sealing layer after contact of the hydrogen with same, the test been carried out as defined in the standard CSA/ANSI CHMC 2: 19, the total proportion of said contaminants extracted in the hydrogen being less than or equal to 3% by weight, in particular less than 2% by weight of the sum of the constituents of the composition.

Provided is a composition for a gas seal member that can form a gas seal member for a high-pressure hydrogen device that is capable of sufficiently inhibiting both swelling destruction and blister destruction. The composition for a gas seal member is a composition for a gas seal member used in a high-pressure hydrogen environment and contains an elastomer and fibrous carbon nanostructures. The fibrous carbon nanostructures are contained in a proportion of not less than 1 part by mass and not more than 10 parts by mass per 100 parts by mass of the elastomer. An area fraction S (%) of aggregates of the fibrous carbon nanostructures in a cross-section of the composition for a gas seal member and a volume percentage V (volume %) of the fibrous carbon nanostructures in the composition for a gas seal member satisfy a relationship 0≤S/V≤2.0.

Disclosed is a gas seal member for high-pressure hydrogen device with sufficiently reduced occurrence of both swelling destruction and blister destruction. The gas seal member is formed of a cross-linked product of an elastomer composition which comprises an elastomer and fibrous carbon nanostructures, wherein a hydrogen diffusion coefficient D1 of a cross-linked product of an elastomer component including the elastomer and a hydrogen diffusion coefficient D2 of the cross-linked product of the elastomer composition satisfy the relationship 0.7<D2/D1<1.0.

Provided is a composition for a gas seal member that can form a gas seal member for a high-pressure hydrogen device that is capable of sufficiently inhibiting both swelling destruction and blister destruction. The composition for a gas seal member is a composition for a gas seal member used in a high-pressure hydrogen environment and contains an elastomer and fibrous carbon nanostructures. The fibrous carbon nanostructures are contained in a proportion of not less than 1 part by mass and not more than 10 parts by mass per 100 parts by mass of the elastomer. An area fraction S (%) of aggregates of the fibrous carbon nanostructures in a cross-section of the composition for a gas seal member and a volume percentage V (volume %) of the fibrous carbon nanostructures in the composition for a gas seal member satisfy a relationship 0S/V2.0.

Disclosed is a lip seal for water pump made of a rubber-like elastic material, fixed to a housing as a fixed side and in sliding contact with a shaft rotating relative to the housing; the lip seal having sliding surface with a surface roughness Ra (according to JIS B0601 corresponding to ISO 4287) of 1 to 30 m, being obtained by vulcanization-molding of a rubber composition comprising 100 parts by weight of the rubber-like elastic material, 1 to 150 parts by weight of a reinforcing filler, 5 to 90 parts by weight of a non-reinforcing filler having an average particle diameter of 1 m or more, 0.1 to 5 parts by weight of a coupling agent, 1 to 15 parts by weight of a co-crosslinking agent, and 0.5 to 10 parts by weight of an organic peroxide. The lip seal effects to prevent softening and volume swelling of the rubber-like elastic material and furthermore the generation of deposits in the rotating shaft, which are problematic for rotation torque and LLC resistance.

The present disclosure provides a high-pressure hydrogen apparatus gas seal member which is excellent in durability and is capable of sufficiently suppressing an occurrence of a blister fracture. A high-pressure hydrogen apparatus gas seal member of the present disclosure is a high-pressure hydrogen apparatus gas seal member made of a crosslinked product of an elastomer composition which comprises an elastomer and fibrous carbon nanostructures having an average length of 100 m or more and 1000 m or less, wherein the fibrous carbon nanostructures have a surface fractal dimension of 2.3 or more and 3.0 or less or a radius of gyration of 50 nm or more and 500 nm or less, and further the fibrous carbon nanostructures has an inner diameter of 4.0 nm or less.

To provide a sealing resin composition and a seal that are capable of being used, in particular, in high temperature and high pressure gas, in particular hydrogen gas. A sealing resin composition is used in a piston ring 1 for sealing gas. When a molded body of the sealing resin composition is exposed to gas with a pressure of 82 MPa and a temperature of 200 C. for 192 hours, a dimensional change rate of the molded body relative to the molded body before the exposure is +1.0% or less, a retention rate of the tensile strength of the molded body after the exposure is 80% or more as the tensile strength of the molded body before the exposure is defined as 100%. The tensile strength of the molded body of the sealing resin composition is 100 MPa or more by a measuring method based on ASTM D638.