Abstract: Provided is a vulcanized rubber surface treatment agent that enables firm adhesion between vulcanized rubbers without heating and has little effect on rubber deterioration. The vulcanized rubber surface treatment agent is used for adhering vulcanized rubbers to each other, which is an aqueous solution of hypochlorous acid having a pH value of 2 or more and 7 or less and an effective chlorine concentration of 100 ppm or more and 13000 ppm or less.

Abstract: Provided is a thin film with good durability that is easy to handle during storage and use. The film contains, as a rubber component, at least a copolymer having a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit, and having a proportion of a butylene unit of 0 mol %, where a filler content is 15 parts by mass or less with respect to 100 parts by mass of the rubber component, no cross-linking agent is contained, and the thickness is 300 ?m or less.

Abstract: The present invention relates to a steel cord-rubber composite including a rubber composition and a steel cord, wherein the rubber composition is a rubber composition containing a rubber component, a filler, a thermosetting resin, a methylene donor, a thiuram-based vulcanization accelerator, and a sulfenamide-based vulcanization accelerator; the content of a cobalt compound is 0.01 parts by mass or less; and the steel cord is a steel cord subjected to ternary alloy plating. The steel cord-rubber composite improves not only the adhesiveness of the steel cord-rubber composite, particularly the adhesiveness after hygrothermal aging, but also improves the crack propagation resistance and the low fuel consumption of the pneumatic tire using this steel cord-rubber composite and favorably makes the both compatible with each other.

Abstract: An object of the present disclosure is to provide a rubber composition possessing both satisfactory low exothermic property and satisfactory durability in adhesion to metal, crack resistance, and the like in a compatible manner. Specifically, a rubber composition comprises: a rubber component; N-cyclohexyl-2-benzothiazolylsulfenamide; a nitrogenous cyclic compound having no benzene ring; a cobalt compound containing no boron; and silica, wherein a content of the nitrogenous cyclic compound is 0.4 parts by mass or less with respect to 100 parts by mass of the rubber component, and a mass ratio (Co/N) of the cobalt content (Co) in the cobalt compound with respect to the nitrogen content (N) in the nitrogenous cyclic compound is in the range of 1.2 to 7.0.

Abstract: To provide a piston ring comprising a hard carbon film that is easy to form and exhibits excellent wear resistance. The above-described problem is solved by having a hard carbon film 4 formed on at least an outer peripheral sliding surface 11 of a piston ring base material 1, wherein the hard carbon film 4 is a laminated film comprising a plurality of layers, and is configured so as to contain boron within a range of an atomic density of 0.2×1022 atoms/cm3 to 2.0×1022 atoms/cm3 inclusive. This hard carbon film 4 may be configured to have an sp2 component ratio within a range of 40% to 80% inclusive, measured in a TEM-EELS spectrum formed by combining electron energy loss spectroscopy (EELS) with a transmission electron microscope (TEM), and a hydrogen content within a range of 0.1 atom % to 5 atom % inclusive. Further, a total thickness of this hard carbon film 4 may be configured to be within a range of 0.5 ?m to 20 ?m inclusive.

Abstract: To provide a piston ring comprising a hard carbon film that is easy to form and exhibits excellent adhesion and wear resistance, and a manufacturing method therefor. The above-described problem is solved by means of a piston ring comprising a hard carbon film 50 formed on at least an outer peripheral sliding surface 11 of a piston ring base material 1, wherein the hard carbon film 50 is a laminated film comprising a plurality of layers, including an upper layer 5 with a lamination pitch within a range of 3 nm to 50 nm inclusive, a middle layer 4 with a lamination pitch less than that of the upper layer 5, and a lower layer 3 with a lamination pitch within the same range as that of the upper layer 5 and greater than that of the middle layer 4.

Abstract: A piston ring having a hard carbon film formed on at least an external peripheral sliding surface of a piston ring base material, the hard carbon film having an sp2 component ratio within a range of 40% to 80% inclusive as measured by a TEM-EELS spectrum which combines electron energy loss spectroscopy (EELS) with a transmission electron microscope (TEM), a hydrogen content being in a range of 0.1 at. % to 5 at. % inclusive, and an amount of macroparticles appearing on the surface being within a range of 0.1% to 10% inclusive by area ratio. The hard carbon film is formed on a hard carbon foundation film formed under low-speed film-forming conditions on the side of the piston ring base material, and the hard carbon foundation film is formed with an arc current value 80% or less of the arc current value during the formation of the hard carbon film.

Abstract: To provide a piston ring comprising a hard carbon film that is easy to form and exhibits excellent wear resistance. The above-described problem is solved by having a hard carbon film 4 formed on at least an outer peripheral sliding surface 11 of a piston ring base material 1, wherein the hard carbon film 4 is a laminated film comprising a plurality of layers, and is configured so as to contain boron within a range of an atomic density of 0.2×1022 atoms/cm3 to 2.0×1022 atoms/cm3 inclusive. This hard carbon film 4 may be configured to have an sp2 component ratio within a range of 40% to 80% inclusive, measured in a TEM-EELS spectrum formed by combining electron energy loss spectroscopy (EELS) with a transmission electron microscope (TEM), and a hydrogen content within a range of 0.1 atom % to 5 atom % inclusive. Further, a total thickness of this hard carbon film 4 may be configured to be within a range of 0.5 ?m to 20 ?m inclusive.

Abstract: To provide a piston ring comprising a hard carbon film that is easy to form and exhibits excellent adhesion and wear resistance, and a manufacturing method therefor. The above-described problem is solved by means of a piston ring comprising a hard carbon film 50 formed on at least an outer peripheral sliding surface 11 of a piston ring base material 1, wherein the hard carbon film 50 is a laminated film comprising a plurality of layers, including an upper layer 5 with a lamination pitch within a range of 3 nm to 50 nm inclusive, a middle layer 4 with a lamination pitch less than that of the upper layer 5, and a lower layer 3 with a lamination pitch within the same range as that of the upper layer 5 and greater than that of the middle layer 4.

Abstract: A piston ring having a hard carbon coating film is provided that can be easily formed in the same batch, does not cause delamination, and is excellent in initial running-in and wear resistance. A hard carbon coating film is formed at least on an outer peripheral sliding surface of a piston ring base and contains substantially no hydrogen, wherein the hard carbon coating film has an sp2 content ratio ranging from 40% to 80% measured in a TEM-EELS spectrum where transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) are combined together, and an area ratio of contained macro particles on a surface of the hard carbon coating film ranges from 0.1% to 10.0%.

Abstract: The object is to solve the issue of an over-steered state at an exit straight portion in addition to enhance a curve passage performance than when a steering angle of front and rear axles is set at a radial steering angle. A steering method for a steering device intentionally turns two axles (12a, 12b) of a truck (12) of a railway vehicle relative to a frame of the truck. The two axles are arranged at front and rear of the truck with respect to a direction of running of the railway vehicle. The steering method includes steering the axles such that a steering angle (?1) of the front axle (12a) is larger than a steering angle (?2) of the rear axle (12b).

Abstract: A piston ring having a hard carbon film formed on at least an external peripheral sliding surface of a piston ring base material, the hard carbon film having an sp2 component ratio within a range of 40% to 80% inclusive as measured by a TEM-EELS spectrum which combines electron energy loss spectroscopy (EELS) with a transmission electron microscope (TEM), a hydrogen content being in a range of 0.1 at. % to 5 at. % inclusive, and an amount of macroparticles appearing on the surface being within a range of 0.1% to 10% inclusive by area ratio. The hard carbon film is formed on a hard carbon foundation film formed under low-speed film-forming conditions on the side of the piston ring base material, and the hard carbon foundation film is formed with an arc current value 80% or less of the arc current value during the formation of the hard carbon film.

Abstract: A piston ring having a hard carbon coating film is provided that can be easily formed in the same batch, does not cause delamination, and is excellent in initial running-in and wear resistance. A hard carbon coating film is formed at least on an outer peripheral sliding surface of a piston ring base and contains substantially no hydrogen, wherein the hard carbon coating film has an sp2 content ratio ranging from 40% to 80% measured in a TEM-EELS spectrum where transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) are combined together, and an area ratio of contained macro particles on a surface of the hard carbon coating film ranges from 0.1% to 10.0%.

Abstract: The object is to solve the issue of an over-steered state at an exit straight portion in addition to enhance a curve passage performance than when a steering angle of front and rear axles is set at a radial steering angle. A steering method for a steering device intentionally turns two axles (12a, 12b) of a truck (12) of a railway vehicle relative to a frame of the truck. The two axles are arranged at front and rear of the truck with respect to a direction of running of the railway vehicle. The steering method includes steering the axles such that a steering angle (?1) of the front axle (12a) is larger than a steering angle (?2) of the rear axle (12b).