Abstract: Provided is a fluororubber composition capable of providing a crosslinked fluororubber article that exhibits not only heat resistance, but also excellent mechanical properties at high temperatures. The fluororubber composition includes a fluororubber (A), a carbon black (B), and an aromatic petroleum resin (E), and the fluororubber composition has a difference ?G? (G? (1%)?G? (100%)) of not lower than 120 kPa and not higher than 3,000 kPa, where G? (1%) denotes a shear modulus at a dynamic strain of 1%, G? (100%) denotes a shear modulus at a dynamic strain of 100%, and G? (1%) and G? (100%) are determined by a dynamic viscoelasticity test carried out on an unvulcanised rubber with a rubber process analyzer (RPA) in a condition that the measurement frequency is 1 Hz and the measurement temperature is 100° C.

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: 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: A diaphragm including a cross-linked fluororubber layer obtained 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 400 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%, static tension under a constant static load condition for measuring strain distribution: 157 cN, and frequency: 10 Hz.

Abstract: A fluororubber composition including a fluororubber having an iodine content of 10 to 90 mol % for the total mole of the polymer end groups and a carbon black (B), wherein a difference (?G?), represented by G?(1%)-G?(100%), is not lower than 120 kPa and not higher than 3,000 kPa, where G?(1%) denotes a shear modulus at a dynamic strain of 1% under an uncrosslinked state and G?(100%) denotes a shear modulus at a dynamic strain of 100% under an uncrosslinked state, and G?(1%) and G?(100%) are determined by a dynamic viscoelasticity test with a rubber process analyzer (RPA) in a condition that the measurement frequency is 1 Hz and the measurement temperature is 100° C.

Abstract: A fluororubber composition which includes a fluororubber (A) and a carbon black (B). The fluororubber (A) is a vinylidene fluoride-based fluororubber including a structural unit (VdF unit) derived from vinylidene fluoride and a structural unit derived from at least one monomer selected from the group consisting of hexafluoropropylene (HFP), 2,3,3,3-tetrafluoro propylene, and perfluoro(alkyl vinyl ether) (PAVE). The molar ratio of the VdF unit to the structural unit derived from at least one monomer selected from the group consisting of HFP, 2,3,3,3-tetrafluoro propylene, and PAVE is 50/50 to 78/22. The fluororubber composition has a difference ?G? (G? (1%)-G? (100%)) of not lower than 120 kPa and not higher than 3,000 kPa, where G? (1%) denotes a modulus of shearing elasticity at a dynamic strain of 1%, G? (100%) denotes a modulus of shearing elasticity at a dynamic strain of 100%, and G? (1%) and G? (100%) are determined by a dynamic viscoelasticity test.

Abstract: The invention provides a fluororubber composition able to produce a crosslinked fluororubber article that exhibits not only heat resistance, but also excellent mechanical properties at high temperatures, and a method for producing same. The fluororubber composition contains: a fluororubber (A); and carbon black (B), wherein when the aforementioned fluororubber composition is immersed for 160 hours in an extraction solvent of acetone and hexane at an acetone:hexane mass ratio of 42.29:57.71 at 40° C. and an extraction residue that is not extracted and remains as a solid is separated from the aforementioned extraction solvent and dried and then the dry weight of the extraction residue is measured, the quantity of a solvent-insoluble polymer is not lower than 5%.

Abstract: The present invention provides a method for producing a fluoroelastomer using an emulsifier which is inexpensive and hardly remains in product polymers. The present invention is related to a method for producing a fluoroelastomer, wherein vinylidene fluoride and at least one fluoroolefin monomer other than vinylidene fluoride are copolymerized in the manner of an emulsion polymerization in the presence of an emulsifier represented by C5F11COOM, wherein M represents H, NH4 or an alkali metal.

Abstract: Provided is a fluororubber composition capable of providing a crosslinked fluororubber article that exhibits not only heat resistance, but also excellent mechanical properties at high temperatures. The fluororubber composition includes a fluororubber (A), a carbon black (B), and an aromatic petroleum resin (E), and the fluororubber composition has a difference ?G? (G? (1%)?G? (100%)) of not lower than 120 kPa and not higher than 3,000 kPa, where G? (1%) denotes a shear modulus at a dynamic strain of 1%, G? (100%) denotes a shear modulus at a dynamic strain of 100%, and G? (1%) and G? (100%) are determined by a dynamic viscoelasticity test carried out on an unvulcanised rubber with a rubber process analyzer (RPA) in a condition that the measurement frequency is 1 Hz and the measurement temperature is 100° C.

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 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: A fluororubber composition which includes a fluororubber (A) and a carbon black (B). The fluororubber (A) is a vinylidene fluoride-based fluororubber including a structural unit (VdF unit) derived from vinylidene fluoride and a structural unit derived from at least one monomer selected from the group consisting of hexafluoropropylene (HFP), 2,3,3,3-tetrafluoro propylene, and perfluoro(alkyl vinyl ether) (PAVE). The molar ratio of the VdF unit to the structural unit derived from at least one monomer selected from the group consisting of HFP, 2,3,3,3-tetrafluoro propylene, and PAVE is 50/50 to 78/22. The fluororubber composition has a difference ?G? (G? (1%)-G? (100%)) of not lower than 120 kPa and not higher than 3,000 kPa, where G? (1%) denotes a modulus of shearing elasticity at a dynamic strain of 1%, G? (100%) denotes a modulus of shearing elasticity at a dynamic strain of 100%, and G? (1%) and G? (100%) are determined by a dynamic viscoelasticity test.

Abstract: A fluororubber composition including a fluororubber having an iodine content of 10 to 90 mol % for the total mole of the polymer end groups and a carbon black (B), wherein a difference (?G?), represented by G?(1%)-G?(100%), is not lower than 120 kPa and not higher than 3,000 kPa, where G?(1%) denotes a shear modulus at a dynamic strain of 1% under an uncrosslinked state and G?(100%) denotes a shear modulus at a dynamic strain of 100% under an uncrosslinked state, and G?(1%) and G?(100%) are determined by a dynamic viscoelasticity test with a rubber process analyzer (RPA) in a condition that the measurement frequency is 1 Hz and the measurement temperature is 100° C.

Abstract: The invention provides a method for producing a fluororubber composition that is able to give a crosslinked article that exhibits not only heat resistance, but also excellent mechanical properties at high temperatures. A method for producing a fluororubber composition includes: a step (1-1) of mixing a fluororubber (A) and a carbon black (B) by means of an internal mixer until the maximum temperature reaches 80 to 220° C. so as to obtain an intermediate composition; a step (1-2) of cooling the intermediate composition to a temperature of less than 50° C.; and a step (2-1) of mixing the cooled intermediate composition until the maximum temperature reaches not lower than 10° C. but lower than 80° C. so as to obtain a fluororubber composition.

Abstract: The invention provides a fluororubber composition able to produce a crosslinked fluororubber article that exhibits not only heat resistance, but also excellent mechanical properties at high temperatures, and a method for producing same. The fluororubber composition contains: a fluororubber (A); and carbon black (B), wherein when the aforementioned fluororubber composition is immersed for 160 hours in an extraction solvent of acetone and hexane at an acetone:hexane mass ratio of 42.29:57.71 at 40° C. and an extraction residue that is not extracted and remains as a solid is separated from the aforementioned extraction solvent and dried and then the dry weight of the extraction residue is measured, the quantity of a solvent-insoluble polymer is not lower than 5%.

Abstract: A noncrystalline fluoroelastomer which is a copolymer consisting essentially of vinylidene fluoride and a fluoromonomer represented by the general formula (1): CH2?CFRf??(1) wherein Rf is a straight or branched fluoroalkyl group containing 1 to 12 carbon atoms, and has a vinylidene fluoride units/fluoromonomer units mol ratio of 78/22 to 22/78 and a glass transition temperature of not higher than 25° C.

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: A diaphragm including a cross-linked fluororubber layer obtained 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 400 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%, static tension under a constant static load condition for measuring strain distribution: 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: The present invention provides a method of producing a fluoroelastomer excellent in dispersion stability at low cost, at a high rate of polymerization and in high yields. The present invention is a method of producing a fluoroelastomer comprising an emulsion polymerization of a fluorinated monomer in the presence of a water-soluble radical polymerization initiator, wherein the emulsion polymerization is carried out in the presence of a compound (1) containing a functional group reactive in radical polymerization and a hydrophilic group and a fluorinated compound (2) containing a fluorocarbon group comprising 1 to 6 continuously united carbon atom with fluorine atom directly bound to each of them as well as a hydrophilic group.