Abstract: A production method comprising the steps of: spraying an aluminum hydroxide powder having a specific surface area measured by a nitrogen adsorption method of 0.3 m2/g or more and 3 m2/g or less; a ratio of an average particle diameter D50, which is a particle diameter at which 50% by weight of particles from the finest particle side are accumulated in a particle diameter distribution measured by a laser diffraction scattering method, to a sphere conversion particle diameter Dbet calculated from a specific surface area, of 10 or less; and the average particle diameter D50 of 2 ?m or more and 100 ?m or less, into flames, and then collecting it in the form of a powder to give a spherical alumina powder having a small specific surface area and a low uranium content, and capable of providing high thermal conductivity to resin compositions.

Abstract: A fluororubber composition which (1) is clean, (2) achieves a higher specific gravity, (3) achieves a better physical property in terms of breaking elongation, (4) is free of halogen substance (chlorine), and (5) provides a rubber surface which is non-tacky to metal(s); and a method for producing a crosslinked fluororubber product. The fluororubber composition includes a peroxide-crosslinkable fluororubber comprising a terfluoropolymer; barium sulfate; a peroxide crosslinking agent; and a salt having BF4? as a counter ion; wherein the barium sulfate is included in an amount of 50 to 180 parts by weight based on 100 parts by weight of the fluoropolymer; and wherein the salt having BF4? as a counter ion is included in an amount of 0.7 to 1.5 parts by weight based on 100 parts by weight of the fluoropolymer.

Abstract: A fluororubber composition which (1) is clean, (2) achieves a higher specific gravity, (3) achieves a better physical property in terms of breaking elongation, (4) is free of halogen substance (chlorine), and (5) provides a rubber surface which is non-tacky to metal(s); and a method for producing a crosslinked fluororubber product. The fluororubber composition includes a peroxide-crosslinkable fluororubber comprising a terfluoropolymer; barium sulfate; a peroxide crosslinking agent; and a salt having BF4? as a counter ion; wherein the barium sulfate is included in an amount of 50 to 180 parts by weight based on 100 parts by weight of the fluoropolymer; and wherein the salt having BF4? as a counter ion is included in an amount of 0.7 to 1.5 parts by weight based on 100 parts by weight of the fluoropolymer.

Abstract: A production method comprising the steps of: spraying an aluminum hydroxide powder having a specific surface area measured by a nitrogen adsorption method of 0.3 m2/g or more and 3 m2/g or less; a ratio of an average particle diameter D50, which is a particle diameter at which 50% by weight of particles from the finest particle side are accumulated in a particle diameter distribution measured by a laser diffraction scattering method, to a sphere conversion particle diameter Dbet calculated from a specific surface area, of 10 or less; and the average particle diameter D50 of 2 ?m or more and 100 ?m or less, into flames, and then collecting it in the form of a powder to give a spherical alumina powder having a small specific surface area and a low uranium content, and capable of providing high thermal conductivity to resin compositions.

Abstract: [Problem] To provide a fluororubber composition which (1) achieves an excellent shock absorbing property upon collision with an arm, (2) achieves non-tackiness, (3) is clean, and (4) is free of halogen substance (chlorine); and a method for producing a crosslinked fluororubber product. [Means for Solving the Problem] A fluororubber composition comprising: a polyol-crosslinkable fluororubber comprising a fluoropolymer; a polyol crosslinking agent; and a salt having BF4? as a counter ion; wherein the polyol crosslinking agent is included as an effective component in an amount of 1.25 to 3.0 parts by weight based on 100 parts by weight of the fluoropolymer; and wherein the salt having BF4? as a counter ion is included in an amount of 0.700 to 0.

Abstract: It is an object of the present invention to provide a fluororubber composition for cell seals of fuel cells, which can improve quality, productivity, etc. of a cell seal of a fuel cell by crosslinking a burr formed by an air vent area in the molding process for producing a cell seal of a fuel cell and thereby preventing separation of a fuel cell gasket. The fluororubber composition for cell seals of fuel cells of the present invention comprises a peroxide-crosslinkable fluorine-containing rubber (A) having a fluorine content of not less than 64% by weight and having a crosslinking site derived from a bromine-containing and/or iodine-containing compound, an organic peroxide (B) in an amount of 0.

Abstract: A fluororubber composition which (1) is clean, (2) achieves a higher specific gravity, (3) achieves a better physical property in terms of breaking elongation, (4) is free of halogen substance (chlorine), and (5) provides a rubber surface which is non-tacky to metal(s); and a method for producing a crosslinked fluororubber product. The fluororubber composition includes a peroxide-crosslinkable fluororubber comprising a terfluoropolymer; barium sulfate; a peroxide crosslinking agent; and a salt having BF4? as a counter ion; wherein the barium sulfate is included in an amount of 50 to 180 parts by weight based on 100 parts by weight of the fluoropolymer; and wherein the salt having BF4? as a counter ion is included in an amount of 0.7 to 1.5 parts by weight based on 100 parts by weight of the fluoropolymer.