Abstract: The present invention provides a belt excellent in mechanical properties at high temperatures. The belt of the present invention comprises a cross-linked fluororubber layer obtainable by cross-linking a fluororubber composition containing a fluororubber (A) and a carbon black (B). The cross-linked fluororubber layer has a loss modulus E? of 400 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test (measurement temperature: 160° C., tensile strain: 1%, initial force: 157 cN, frequency: 10 Hz).

Abstract: A fluoroelastomer mixture, including: a peroxide-vulcanizable fluoroelastomer (A) containing an iodine atom; and a peroxide-vulcanizable fluoroelastomer (B) containing an iodine atom. The fluoroelastomer (A) is a copolymer (a1) consisting of 50 to 85 mol % of a vinylidene fluoride unit and 15 to 50 mol % of a perfluoro(alkyl vinyl ether) unit, or a copolymer (a2) consisting of 45 to 85 mol % of a vinylidene fluoride unit, 1 to 30 mol % of a tetrafluoroethylene unit, and 14 to 30 mol % of a perfluoro(alkyl vinyl ether) unit. Further the fluoroelastomer (B) has a fluorine content of 70.0% or more. Also disclosed is a composition for peroxide vulcanization containing the above fluoroelastomer composition (i), a polyfunctional unsaturated compound (ii) and a peroxide (iii), as well as a method for producing the fluoroelastomer mixture.

Abstract: There is provided a fluorine-containing elastomer composition assuring easy kneading and providing a crosslinked article having improved strength. The fluorine-containing elastomer composition comprises (A) an elastomer of a vinylidene fluoride/hexafluoropropylene copolymer having a branching coefficient of 30 to 300 ppm, a Mooney viscosity (ML1+10: 121° C.) of 7 to 80 and a molecular weight distribution (Mw/Mn) of 1.5 to 4, and (B) an elastomer of a vinylidene fluoride/hexafluoropropylene copolymer having a storage modulus G? at 180° C. at 500 cpm of 500 to 900, and a mass ratio of (A)/(B) is 70/30 to 90/10.

Abstract: The present invention provides a complex-shaped fluororubber formed product having excellent demoldability in molding. The complex-shaped fluororubber formed product of the present invention comprises a cross-linked fluororubber layer obtainable by cross-linking a fluororubber composition containing a fluororubber (A) and a carbon black (B). The cross-linked fluororubber layer has a loss modulus E? of 400 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test (measurement temperature: 160° C., tensile strain: 1%, initial force: 157 cN, frequency: 10 Hz).

Abstract: The present invention provides a fluororubber composition that has excellent heat resistance and excellent mechanical properties at high temperatures. The fluororubber composition comprises a peroxide cross-linkable fluororubber (A); a carbon black (B); a peroxide cross-linking agent (C); and a low-self-polymerizing cross-linking accelerator (D), wherein to 100 parts by mass of the fluororubber (A), the amount of the carbon black (B) is 5 to 50 parts by mass, the amount of the cross-linking agent (C) is 0.01 to 10 parts by mass, and the amount of the cross-linking accelerator (D) is 2.5 parts by mass or smaller.

Abstract: The present invention provides a vibration isolation rubber excellent not only in heat-aging resistance and oil resistance but also in mechanical properties at high temperatures. The vibration isolation rubber of the present invention comprises a cross-linked fluororubber layer obtainable by cross-linking a fluororubber composition containing a fluororubber (A) and a carbon black (B). The cross-linked fluororubber layer has a loss modulus E? of 400 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test (measurement temperature: 160° C., tensile strain: 1%, initial force: 157 cN, and frequency: 10 Hz).

Abstract: The present invention provides a fluororubber composition that has excellent heat resistance and excellent mechanical properties at high temperatures. The fluororubber composition comprises 100 parts by mass of a peroxide cross-linkable fluororubber (A); 5 to 50 parts by mass of a carbon black (B); 0.1 to 10 parts by mass of a peroxide cross-linking agent (C); and 10 parts by mass or smaller of a bisolefin (D).

Abstract: To provide a sealing material which is excellent in sealability under high-temperature conditions as well as crack resistance at high temperatures and high compression. A sealing material comprising a cross-linked fluororubber layer obtainable by cross-linking a fluororubber composition containing a fluororubber (A) and a carbon black (B), the cross-linked fluororubber layer having a loss modulus E? of 600 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test under conditions of measurement temperature: 160° C., tensile strain: 1%, initial force: 157 cN, and frequency: 10 Hz.

Abstract: The present invention provides a method for producing a fluororubber composition that has excellent heat resistance and excellent mechanical properties at high temperatures. The production method comprises the step of mixing a fluororubber (A) and a carbon black (B) in the presence of an organic amine compound (C1) and/or an acid acceptor (C2) to prepare a mixed product, wherein the mixed product has a highest temperature Tm of 80° C. to 220° C. while being mixed and has a highest temperature of 80° C. to 220° C. upon being discharged.

Abstract: To provide a fluororubber formed product having excellent heat resistance and excellent mechanical properties at high temperatures. A formed product comprising: a cross-linked fluororubber product obtained by cross-link-molding a fluororubber composition containing a fluororubber (A) and a carbon black (B), the cross-linked fluororubber product having a loss modulus E? of 400 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test under conditions of a measurement temperature of 160° C., tensile strain of 1%, initial force of 157 cN, and frequency of 10 Hz.

Abstract: The present invention provides a fluororubber formed product having excellent heat resistance and excellent mechanical properties at high temperatures. The formed product comprises a cross-linked fluororubber product obtainable by cross-linking a fluororubber composition containing a fluororubber (A) and a carbon black (B), the fluororubber (A) being a vinylidene fluoride fluororubber including 48 to 88 mol % of a structural unit derived from vinylidene fluoride and 0 to 10 mol % of a structural unit derived from tetrafluoroethylene relative to the total amount 100 mol % of structural units derived from all monomer components, the cross-linked fluororubber product having a loss modulus E? of 400 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test (measurement temperature: 160° C., tensile strain: 1%, initial force: 157 cN, and frequency: 10 Hz).

Abstract: The present invention provides a hose excellent in mechanical properties at high temperatures. The hose of the present invention comprises a cross-linked fluororubber layer obtainable by cross-linking a fluororubber composition containing a fluororubber (A) and a carbon black (B). The cross-linked fluororubber layer has a loss modulus E? of 400 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test (measurement temperature: 160° C., tensile strain: 1%, initial force: 157 cN, frequency: 10 Hz).

Abstract: The present invention provides a belt excellent in mechanical properties at high temperatures. The belt of the present invention comprises a cross-linked fluororubber layer obtainable by cross-linking a fluororubber composition containing a fluororubber (A) and a carbon black (B). The cross-linked fluororubber layer has a loss modulus E? of 400 kPa or higher and 6,000 kPa or lower determined by a dynamic viscoelasticity test (measurement temperature: 160° C., tensile strain: 1%, initial force: 157 cN, frequency: 10 Hz).

Abstract: A fluoroelastomer mixture, including: a peroxide-vulcanizable fluoroelastomer (A) containing an iodine atom; and a peroxide-vulcanizable fluoroelastomer (B) containing an iodine atom. The fluoroelastomer (A) is a copolymer (a1) consisting of 50 to 85 mol % of a vinylidene fluoride unit and 15 to 50 mol % of a perfluoro(alkyl vinyl ether) unit, or a copolymer (a2) consisting of 45 to 85 mol % of a vinylidene fluoride unit, 1 to 30 mol % of a tetrafluoroethylene unit, and 14 to 30 mol % of a perfluoro(alkyl vinyl ether) unit. Further the fluoroelastomer (B) has a fluorine content of 70.0% or more. Also disclosed is a composition for peroxide vulcanization containing the above fluoroelastomer composition (i), a polyfunctional unsaturated compound (ii) and a peroxide (iii), as well as a method for producing the fluoroelastomer mixture.

Abstract: A curable composition comprising (A) a vinylidene fluoride elastomer which is a copolymer of vinylidene fluoride (a1), at least one kind of perfluoroolefin (a2) selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoro(alkyl vinyl ether) and a cyano group-containing monomer (a3) (a proportion of the vinylidene fluoride exceeds 20% by mole), (B) a specific curing agent and (C) a compound generating ammonia at 40° to 330° C. The present invention can provide a curable composition of a vinylidene fluoride elastomer assuring improved crosslinking speed, and a molded article obtained from the curable composition. Physical properties under normal conditions are improved by the presence of a solvent having affinity for the compound generating ammonia.

Abstract: A curable composition comprising (A) a vinylidene fluoride type elastomer which is a copolymer of vinylidene fluoride (a1), at least one perfluoroolefin (a2) selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoro(alkyl vinyl ether) and a cyano group-containing monomer (a3) (the proportion of vinylidene fluoride exceeds 20% by mole), and (B) a compound generating ammonia at 40° to 330° C. alone as a curing agent. The present invention can provide a curable composition of a vinylidene fluoride type elastomer assuring improved crosslinking speed and making it possible to use a cheap curing agent, and a molded article obtained from the curable composition. Physical properties under normal conditions can also be improved by the presence of the solvent having affinity for the compound generating ammonia.

Abstract: There is provided a fluorine-containing elastomer composition assuring easy kneading and providing a crosslinked article having improved strength. The fluorine-containing elastomer composition comprises (A) an elastomer of a vinylidene fluoride/hexafluoropropylene copolymer having a branching coefficient of 30 to 300 ppm, a Mooney viscosity (ML1+10: 121° C.) of 7 to 80 and a molecular weight distribution (Mw/Mn) of 1.5 to 4, and (B) an elastomer of a vinylidene fluoride/hexafluoropropylene copolymer having a storage modulus G? at 180° C. at 500 cpm of 500 to 900, and a mass ratio of (A)/(B) is 70/30 to 90/10.