Abstract: The seal ring is annular around an axis x and includes an annular outer peripheral surface facing an outer periphery side, and a plurality of recessed parts. The recessed parts are formed in such a way as to be spaced apart from each other in a circumferential direction and are recessed from the outer peripheral surface toward an inner periphery side. The recessed parts expand, in the axis x direction, from one side surface to a position which does not reach another side surface. The outer peripheral surface includes a annular contact surface between the another side surface and the position, and rib surfaces respectively between mutually neighboring recessed parts in the circumferential direction. Each of the rib surfaces extends between the one side surface and the position in the axis x direction.

Abstract: An NBR composition, that is excellent in rubber material processability and vulcanized rubber hardness, comprising 93 to 105 parts by weight of carbon black with a carbon black grade of N330 or N550, 1.0 to 4.0 parts by weight of a vulcanization retarder, 2.0 to 5.0 parts by weight of thiazole-based and thiuram-based vulcanization accelerators, and 1.0 to 4.0 parts by weight of a sulfur-based vulcanizing agent, based on 100 parts by weight of NBR. The vulcanized molded product obtained from the NBR composition has a rubber hardness (Duro A, instant) of 85 or more according to JIS K6253 corresponding to ISO 18517, and can be effectively used as an automobile buffer material such as a stopper for electric power steering, a buffer material for nailers, a buffer material for devices equipped with hydraulic cylinders, or the like.

Abstract: A seal ring is an annular seal ring which is configured to be interposed between first and second members, and seals a gap between the first and second members. The second member is inserted into the first member, and reciprocates in its axial direction with respect to the first member. The seal ring includes an annular base part, an annular innermost end part, and a widening protrusion part. The annular base part has a radially exterior end to contact the first member. The annular innermost end part is integrally formed with a radially interior end of the base part to contact the second member. The widening protrusion part is integrally formed with the innermost end part, and protrudes with respect to the base part in the axial direction of the second member.

Abstract: An acrylic rubber composition comprising 5 to 15 parts by weight of a plasticizer having a solubility parameter SP value (by Small's method) of 8.5 to 10.5 based on 100 parts by weight of super cold resistant grade acrylic rubber having a glass transition point Tg of ?42° C. or less, wherein the acrylic rubber composition can give a vulcanizate with the TR10 value, which is an index of cold resistance, of ?42° C. or less both initially and after oil dipping. In the acrylic rubber composition, first, the ratio of an acrylate monomer that constitutes acrylic rubber is adjusted, thereby the low temperature characteristics can be maintained even in an oil contact environment. This intentionally reduces the oil resistance of the vulcanized rubber molded product, thereby increasing the amount of oil swelling into the vulcanized rubber molded product and improving the flexibility in a low temperature environment.

Abstract: A seal ring has, on an outer peripheral surface side thereof, a pair of recessed parts 140 extending in a circumferential direction on both sides in a width direction thereof to form a projection part 120 between the pair of recessed parts 140, and has a plurality of ribs 130 connected to the projection part 120 and extending to lateral surfaces of the seal ring at intervals in the circumferential direction inside the pair of recessed parts 140, and a plurality of ribs 130 arranged on a sealed region side among the plurality of ribs 130 have lateral-wall surfaces on an upstream side in a relative rotation direction of a housing with respect to a shaft, each of the lateral-wall surfaces having inclined surfaces inclined from the upstream side to a downstream side in the relative rotation direction of the housing from the projection part 120 toward the lateral surfaces of the seal ring.

Abstract: A fluororubber composition that is a kneaded mixture of a carbon nanotube masterbatch comprising 4 to 20 parts by weight of multilayer carbon nanotubes, which are fibrous carbon nanostructures that do not contain monolayer carbon nanotubes, based on 100 parts by weight of a fluororubber polymer, and a fluororubber raw material comprising at least a fluororubber polymer and a reinforcing filler, in which the multilayer carbon nanotubes are compounded in an amount of 0.5 to 6 wt. % in the kneaded mixture. The kneading is performed using a roll or a kneader when the fluororubber composition is produced. The fluororubber composition can provide a fluororubber crosslinked molded article that exhibits abrasion resistance and blister resistance.

Abstract: A sealing device acts to seal a gap between a housing of a gear reducer and a rotational shaft that bi-directionally rotates, and separates an internal space of the housing in which a grease is stored from an atmosphere side. The sealing device includes a main seal lip protruding radially inward from an inner peripheral surface of an inner cylindrical portion. The main seal lip has an internal-side inclined surface disposed on a side of the internal space and an atmosphere-side inclined surface disposed on the atmosphere side. An auxiliary seal lip protrudes radially inward and toward the internal space from the internal-side inclined surface of the main seal lip. Multiple first spiral structures and multiple second spiral structures are formed on at least one of the atmosphere-side inclined surface of the main seal lip and an inner peripheral surface of the auxiliary seal lip.

Abstract: Provided is an olefin-based rubber composition having low hardness, good thermal conductivity, and good electrical insulation, and applying little load on a manufacturing facility. The olefin-based rubber composition of the present disclosure contains an ethylene-?-olefin-nonconjugated polyene copolymer, at least two types of magnesium carbonate which are small-particle size magnesium carbonate with 0.3 to 5 ?m of an average particle size and large-particle size magnesium carbonate with 7-60 ?m of an average particle size, and a cross-linking agent, wherein the composition contains 400 to 1200 parts by mass of a total content of the two types of magnesium carbonate per 100 parts by mass of the ethylene-?-olefin-nonconjugated polyene copolymer, Shore A hardness conforming to JIS K 6253-3 : 2012 of the olefin-based rubber composition after cross-linking is 80, and thermal conductivity conforming to ASTM D7984 of the olefin-based rubber composition after cross-linking is 2.0 W/m·K or more.

Abstract: A chloroprene rubber composition comprising 0.8 to 4 parts by weight of 2,4,6-trimercapto-s-triazine and 0.5 to 4.5 parts by weight of tetrabenzylthiuram disulfide based on 100 parts by weight of chloroprene rubber. The chloroprene rubber composition maintains processability (scorch time) and productivity (crosslinking rate) equivalent to those of conventionally used crosslinking systems, without using substances subject to environmental regulations in crosslinking systems, and at the same time, improves physical properties, such as strength, elongation, and compression set characteristics.

Abstract: A gasket includes an elastic part containing a rubber having a dynamic-to-static ratio, Kd/Kst, of 2.5 or lower, wherein the dynamic-to-static ratio, Kd/Kst, is a ratio between a dynamic spring constant, Kd, and a static spring constant, Kst. The dynamic spring constant, Kd, represents a constant as measured under conditions of 23±2° C., 100 Hz, and a strain amplitude of 0.1% according to JIS K6394:2007, and the static spring constant, Kst, represents a constant as measured under conditions of 23±2° C. and a strain amplitude of 0.1% according to JIS K6394:2007.

Abstract: A gasket includes an elastic part containing a rubber having a dynamic spring constant of 1.5 g/?m or lower as measured under conditions of 23±2° C., 100 Hz, and a strain amplitude of 0.1% according to JIS K6394:2007.

Abstract: A dust cover and a sealing structure for improving sealing performance by stabilizing a posture of a seal section. A seal section 130 includes: an inner peripheral seal part 131 which is slidable with respect to an outer peripheral surface of a shaft part 310; a dust lip part 132 which is slidable with respect to an end surface of a first flange part 340; and an auxiliary dust lip part 133 provided on an radially inner side of the dust lip part 132, and the auxiliary dust lip part 133 is configured to be slidable with respect to a curved surface 310a which connects the shaft part 310 and the first flange part 340 to each other.

Abstract: An acrylic rubber composition comprising 0.05 to 3.0 parts by weight of a fluorine-containing compound having a melting point of 30 to 100° C., based on 100 parts by weight of acrylic rubber. The acrylic rubber composition that can improve the dispersibility of a processing aid in the compound and the rubber compound handling properties during open roll operation without using a silicone-based processing aid, which causes bleeding of vulcanizates, and that satisfies the various characteristics, such as dimensional stability and heat resistance, of vulcanizates.

Abstract: A biological electrode that includes an electrode member made of a conductive rubber having a plurality of electrode portions in contact with a body of a subject. The plurality of electrode portions are protrusively formed on an electrode portion forming surface of the electrode member and arranged circularly or concentrically on the electrode portion forming surface. Further, each of the plurality of electrode portions is formed so that a cross-sectional area thereof gradually decreases from a proximal end portion thereof toward a distal end portion thereof and a center of a cross section of the distal end portion is positioned radially outward of a center of a cross section of the proximal end portion as viewed from an arrangement center of the plurality of electrode portions.

Abstract: A vibration-proof bush capable of suppressing incomplete fitting of an upper bush and a lower bush. The vibration-proof bush includes an upper bush configured to be mounted on a vehicle body side and a lower bush configured to be fitted to the upper bush are provided, wherein the vibration-proof bush includes interference portions configured to interfere with each other in a process of fitting the lower bush to the upper bush, and the interference portions form a fitting-sound generation structure in which a sound is generated, when the lower bush is fitted to the upper bush during temporary assembling.

Abstract: Provided are a fluororubber composition maintaining rubber properties and excellent in flowability and mold releasability as well as capable of reducing a cross-linking time when molded, and a fluororubber sealing material formed of the fluororubber composition. The fluororubber composition contains a polyol cross-linkable based fluororubber; an aliphatic acid amide based compound; at least one member selected from a phosphoric acid ester based compound, an aliphatic acid ester based compound and a fluorine-containing based compound; and a polyol based cross-linking agent. The fluororubber sealing material is formed of the fluororubber composition.

Abstract: A gasket manufacturing method, which enables an improvement in sealing performance by making the thickness of a gasket formed on a bead on a base member more uniform. The manufacturing method of a separator-integrated gasket includes dispensing a gasket material, and curing the gasket material dispensed on the bead. The bead includes portions having different widths in a short direction thereof. Compared to a moving speed of a dispensing apparatus relative to the separator body in a narrow portion where the width is small, the moving speed is slower in a wide portion having a larger width than the narrow portion.

Abstract: Provided are a ball joint and a dust cover that make it possible to suppress contact of a body portion of the dust cover with the vicinity of a flange portion of a ball stud. A dust cover integrally includes: a deformable bellows-shaped body portion made of an elastic body; a fixed portion made of an elastic body and provided on one end side of the body portion; and a sealing portion made of an elastic body and provided on the other end side of the body portion. The sealing portion includes: an inner peripheral sealing portion configured to be slidable on a part of a shank portion on the opposite side of the shank portion from a spherical portion with respect to a flange portion; and a cover portion that continuously covers, in an outer wall surface of the flange portion, a radially outward tip end portion and a part of a portion that decreases in diameter from the tip end portion toward the spherical portion side.

Abstract: A fluororubber composition comprising 3 to 20 parts by weight of carbon fibers and 1 to 8 parts by weight of carbon nanotubes based on 100 parts by weight of fluororubber. The crosslinked molded article obtained from the fluororubber composition has excellent effects of not only imparting oil film retention, but also improving the material strength of fluororubber due to the combined use of carbon nanotubes, which have high reinforcing properties. Further, the fluororubber composition can give a fluororubber crosslinked product excellent in abrasion resistance and pressure resistance.

Abstract: A coating solution comprising an organic solvent solution containing polyol-crosslinkable fluororubber, a polyol vulcanizing agent, and N-phenyl-3-aminopropyltrialkoxysilane, preferably a coating solution further containing an epoxy resin in addition thereto, and a fluororubber metal laminated sheet formed by applying the above coating solution to a metal sheet, followed by vulcanization. The coating solution can not only impart stability over time to the fluororubber paste, but also improve the interlayer adhesion and abrasion resistance of the fluororubber metal laminated sheet. Therefore, when it is used as a cylinder head gasket, it is possible to cope with the reduction in rigidity due to the increase in combustion pressure of the engine, and with weight saving. As a result, it will greatly contribute to the improvement of fuel efficiency of automobiles.