Abstract: A fluoroelastomer composition containing (a) a polyol-crosslinkable fluoroelastomer, (b) a cross-linking agent for polyol crosslinking, (c) a crosslinking accelerator; and (d) at least one acid acceptor selected from basic magnesium carbonate and magnesium phosphate, wherein the content of a divalent metal oxide is lower than 1 part by mass with respect to 100 parts by mass of the fluoroelastomer (a). Also disclosed is a molded article obtained by crosslinking the fluoroelastomer composition.

Abstract: The invention provides a fluoroelastomer composition capable of providing a molded article that is inexpensive and has excellent heat-aging resistance. The fluoroelastomer composition is a peroxide-crosslinkable fluoroelastomer composition containing a fluorine-containing elastomer that contains 25 to 90 mol % of a unit of vinylidene fluoride, 10 to 75 mol % of a unit of a fluorine-containing monomer other than the vinylidene fluoride, 0 to 10 mol % of a unit of a fluorine-free monomer copolymerizable with the vinylidene fluoride, and 0.1% by mass or less of an iodine atom and a bromine atom; an organic peroxide having a specific structure; and a co-crosslinking agent. The organic peroxide is present in an amount of 0.3 to 10 parts by mass relative to 100 parts by mass of the fluorine-containing elastomer.

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 invention provides a fluoroelastomer composition capable of providing a molded article that is inexpensive and has excellent heat-aging resistance. The fluoroelastomer composition is a peroxide-crosslinkable fluoroelastomer composition containing a fluorine-containing elastomer that contains 25 to 90 mol % of a unit of vinylidene fluoride, 10 to 75 mol % of a unit of a fluorine-containing monomer other than the vinylidene fluoride, 0 to 10 mol % of a unit of a fluorine-free monomer copolymerizable with the vinylidene fluoride, and 0.1% by mass or less of an iodine atom and a bromine atom; an organic peroxide having a specific structure; and a co-crosslinking agent. The organic peroxide is present in an amount of 0.3 to 10 parts by mass relative to 100 parts by mass of the fluorine-containing elastomer.

Abstract: A fluororubber composition including a fluororubber, a silicone rubber, and perfluoropolyether. The fluororubber composition contains the silicone rubber in an amount of 5 to 55 parts by mass relative to 100 parts by mass of the fluororubber and the perfluoropolyether in an amount of 0.5 to 10 parts by mass relative to 100 parts by mass of the fluororubber.

Abstract: There is provided a crosslinkable fluorine-containing rubber composition being capable of giving a fluorine-containing rubber crosslinked and molded article having a low friction coefficient and assuring an increased proportion of a fluorine-containing resin around the surface of a fluorine-containing rubber, a molded article obtained by crosslinking the composition, and a method for producing the molded article. The crosslinkable fluorine-containing rubber composition comprises a fluorine-containing rubber (A) comprising vinylidene fluoride unit, a fluorine-containing resin (B) and a polyol crosslinking agent (C), wherein the fluorine-containing rubber (A) and the fluorine-containing resin (B) are kneaded at a temperature of not less than a temperature being lower by 5° C. than the melting point of the fluorine-containing resin (B).

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 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 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: 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 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: 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: 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 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 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 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: There is provided a crosslinkable fluorine-containing rubber composition being capable of giving a fluorine-containing rubber crosslinked and molded article having a low friction coefficient and assuring an increased proportion of a fluorine-containing resin around the surface of a fluorine-containing rubber, a molded article obtained by crosslinking the composition, and a method for producing the molded article. The crosslinkable fluorine-containing rubber composition comprises a fluorine-containing rubber (A) comprising vinylidene fluoride unit, a fluorine-containing resin (B) and a polyol crosslinking agent (C), wherein the fluorine-containing rubber (A) and the fluorine-containing resin (B) are kneaded at a temperature of not less than a temperature being lower by 5° C. than the melting point of the fluorine-containing resin (B).

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: To provide a novel crosslinking system of fluorine-containing elastomer giving a crosslinked product particularly having improved mechanical strength and compression set at high temperature. A fluorine-containing rubber composition comprising a fluorine-containing elastomer having carboxyl group and/or alkoxycarbonyl group at an end of a trunk chain and/or branched chain as a crosslinkable group.