Abstract: The double-tube heat exchanger has an outer tube and an inner tube inserted into the outer tube, is provided with an inside channel within the inner tube and an outside channel between the inner tube and the outer tube, and is configured to exchange heat between the fluid flowing in the inside channel and the fluid flowing in the outside channel. The inner tube has an uneven portion having unevenness on the outer peripheral surface. A large-diameter sealing portion is interposed between one axial end of the outer tube and the inner tube. A small-diameter sealing portion, which has a smaller diameter than the large-diameter sealing portion, is interposed between the other axial end of the outer tube and the inner tube. The outside channel and the uneven portion are arranged using the difference in axial position and diameter between the large-diameter sealing portion and the small-diameter sealing portion.

Abstract: A refrigerant-transporting hose includes a tubular inner layer 1 in contact with a fluorine refrigerant, an intermediate layer 2 formed on an outer periphery surface thereof, and at least one rubber layer 3 and 5 formed on a further outer periphery thereof, and the inner layer 1 is made of a inner layer material including maleic anhydride-modified polypropylene as a main component and the intermediate layer 2 is made of a intermediate layer material including polyamide resin as a main component.

Abstract: A hose base body of multilayered construction including an inner surface layer, a reinforcing layer and an outer surface layer has uniform inner diameter, outer diameter and wall-thickness over an entire length thereof. A longitudinal end portion of the hose base body is diametrically expanded, and a main hose body is formed with a small diameter main portion, a large diameter swaged portion and a tapered portion. A braid angle of the reinforcing layer is designed 48° to lower than 54° on the main portion, a braid angle of the reinforcing layer is designed over 57° to 68° on the tightened portion, and a braid angle of the reinforcing layer is designed over about 55° to 61° on the tapered portion.

Abstract: A hose base body of multilayered construction including an inner surface layer, a reinforcing layer and an outer surface layer has uniform inner diameter, outer diameter and wall-thickness over an entire length thereof. A longitudinal end portion of the hose base body is diametrically expanded, and a main hose body is formed with a small diameter main portion, a large diameter swaged portion and a tapered portion. A braid angle of the reinforcing layer is designed 48° to lower than 54° on the main portion, a braid angle of the reinforcing layer is designed over 57° to 68° on the tightened portion, and a braid angle of the reinforcing layer is designed over about 55° to 61° on the tapered portion.

Abstract: A vibration absorbing hose excellent in vibration absorbing property, mounting stability and shape retaining property. The vibration absorbing hose comprises at least one rubber layer composed of a rubber composition having a storage elastic modulus (E?) of 20 to 100 MPa at 200 Hz with an elongation strain of 0.1% at an ordinary temperature (about 20° C.), and a damping factor (tan ?) of not lower than 0.4.

Abstract: A vibration absorbing rubber hose having a laminar structure including an inner rubber layer, a reinforcing layer, and an outer rubber layer, which layers are laminated integrally with one another in the order of description in a radially outward direction of the rubber hose, wherein the inner rubber layer is formed of a butyl rubber material and/or a halogenated butyl rubber material while the outer rubber layer is formed of an EPM material consisting of ethylene-propylene copolymer.

Abstract: A sulfur vulcanizing system rubber composition comprises EPDM, zinc as a vulcanization accelerator activator, at least one thiazole type vulcanization accelerator serving to control the dissolution of zinc from the composition, and at least one ultra-accelerator of the thiuram or dithiocarbamate type, these accelerators being preferably combined under specified quantitative limitations. The hose using this rubber composition is particularly suitable for use in a cooling system for an automobile engine, since the dissolution of zinc into a coolant is prevented, thereby preventing the formation of any zinc compound causing the blocking of the hose, or the leakage of the coolant through the seal between the hose and any pipe connected therewith.

Abstract: A refrigerant hose for an air conditioner has an inner wall layer formed of a laminate of an inner resin layer and an outer rubber layer bonded by its vulcanization to the resin layer. The rubber layer is of a composition comprising butyl rubber, an adhesive material based on resorcinol and a vulcanizing agent based on an alkylphenol-formaldehyde resin, and having a bromine content of at least 0.5% by weight. The hose having the inner wall layer surrounded by a reinforcing layer and an outer wall layer exhibits a high adhesive strength even at an elevated temperature between its refrigerant-impermeable resin layer and its water-impermeable rubber layer.

Abstract: A vibration absorbing rubber hose having a laminar structure including an inner rubber layer, a reinforcing layer, and an outer rubber layer, which layers are laminated integrally with one another in the order of description in a radially outward direction of the rubber hose, wherein the inner rubber layer is formed of a butyl rubber material and/or a halogenated butyl rubber material while the outer rubber layer is formed of an EPM material consisting of ethylene-propylene copolymer.

Abstract: A vibration absorbing hose excellent in vibration absorbing property, mounting stability and shape retaining property. The vibration absorbing hose comprises at least one rubber layer composed of a rubber composition having a storage elastic modulus (E′) of 20 to 100 MPa at 200 Hz with an elongation strain of 0.1% at an ordinary temperature (about 20° C.), and a damping factor (tan &dgr;) of not lower than 0.4.

Abstract: A peroxide cure system rubber composition comprises EPDM having a high iodine value and an appropriate ethylene proportion, and preferably at least quinoline as an antioxidant, and is particularly suitable for use in making a hose in a cooling system for an automobile engine. The hose is highly resistant to hot air aging and cracking, though the composition does not contain zinc.

Abstract: A rubber composition comprising: (A) at least one copolymer ingredient selected from the group consisting of ethylene/&agr;-olefin copolymer rubber and ethylene/&agr;-olefin/unconjugated diene copolymer rubber, (B) nickel diisobutyldithiocarbamate, and (C) carbon black, and not containing any compound having zinc; a vulcanized rubber composition obtained by vulcanizing the rubber composition; and a heat-resistant rubber product using the vulcanized rubber composition.

Abstract: The fuel hose of this invention is a fuel hose comprising a tubular fluororesin inner ply and, as laminated onto the peripheral surface thereof, a thermoplastic resin or rubber outer ply, the tubular fluororesin inner ply having been molded from a fluororesin with an F/C ratio, i.e. ratio of the number of fluorine atoms (F) to the number of carbon atoms (C), of not greater than 1.6 and the peripheral surface layer of the fluororesin inner ply having been modified into the following treated layer (A).(A) a layer with a distribution of oxygen atoms and having an F/C ratio, i.e. ratio of the number of fluorine atoms (F) to the number of carbon atoms (C), of not greater than 1.12 and an O/C ratio, i.e. ratio of the number of oxygen atoms (O) to the number of carbon atoms (C), of not less than 0.08.

Abstract: The fuel hose of this invention is a fuel hose comprising a tubular fluororesin inner ply and, as laminated onto the peripheral surface thereof, a thermoplastic resin or rubber outer ply, the tubular fluororesin inner ply having been molded from a fluororesin with an F/C ratio, i.e. ratio of the number of fluorine atoms (F) to the number of carbon atoms (C), of not greater than 1.6 and the peripheral surface layer of the fluororesin inner ply having been modified into the following treated layer (A).(A) a layer with a distribution of oxygen atoms and having an F/C ratio, i.e. ratio of the number of fluorine atoms (F) to the number of carbon atoms (C), of not greater than 1.12 and an O/C ratio, i.e. ratio of the number of oxygen atoms (O) to the number of carbon atoms (C), of not less than 0.08.

Abstract: The fuel hose of this invention is a fuel hose comprising a tubular fluororesin inner ply and, as laminated onto the peripheral surface thereof, a thermoplastic resin or rubber outer ply, the tubular fluororesin inner ply having been molded from a fluororesin with an F/C ratio, i.e. ratio of the number of fluorine atoms (F) to the number of carbon atoms (C), of not greater than 1.6 and the peripheral surface layer of the fluororesin inner ply having been modified into the following treated layer (A). (A) a layer with a distribution of oxygen atoms and having an F/C ratio, i.e. ratio of the number of fluorine atoms (F) to the number of carbon atoms (C), of not greater than 1.12 and an O/C ratio, i.e. ratio of the number of oxygen atoms (O) to the number of carbon atoms (C), of not less than 0.08.