Provided are a perfluoroelastomer composition which contains 100 parts by weight of a perfluoroelastomer containing a constituent unit derived from a nitrile group-containing monomer, and 0.01 to 5 parts by weight of ketjen black; and a sealing material including a crosslinked product of the perfluoroelastomer composition.

A composition including a perfluoroelastomer, carbon black in an amount of 55 to 75 parts by weight per 100 parts by weight of the perfluoroelastomer, and a crosslinking agent represented by the following formula (1): wherein in the formula (1), A is a single bond, —O—, an alkylene group, or a fluoroalkylene group; R.sup.1, R.sup.2, and R.sup.3 are independently a hydrogen atom, a fluorine atom, an alkyl group, or a fluoroalkyl group; and provided that at least one of R.sup.1, R.sup.2, and R.sup.3 is a fluorine atom or a fluoroalkyl group.

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There is provided a copolymer containing tetrafluoroethylene unit and perfluoro(propyl vinyl ether) unit, wherein the copolymer has a content of perfluoro(propyl vinyl ether) unit of 3.9 to 4.9% by mass with respect to the whole of the monomer units, a melt flow rate at 372° C. of 4.0 to 9.0 g/10 min, and the number of functional groups of 40 or less per 10.sup.6 main-chain carbon atoms.

There is provided a copolymer containing tetrafluoroethylene unit and perfluoro(propyl vinyl ether) unit, wherein the copolymer has a content of perfluoro(propyl vinyl ether) unit of 4.6 to 5.1% by mass with respect to the whole of the monomer units, a melt flow rate at 372° C. of 11.0 to 17.0 g/10 min, and the number of functional groups of 40 or less per 10.sup.6 main-chain carbon atoms.

The present invention is directed to perfluoroelastomer compounds comprising carbon black having a particle size of 100 nm or greater; a mineral filler selected from the group consisting of titanium dioxide, barium sulfate, or a combination of these; a cure site monomer; and a curing agent. These perfluoroelastomer compounds, when cured into articles, exhibit desirable compression stress relaxation properties.

Provided area perfluoroelastomer composition containing a perfluoroelastomer and a compound having a perylene skeleton, in which the compound having a perylene skeleton is a compound other than perylene and 3,4,9,10-perylenetetracarboxylic acid diimide; and a sealing material containing a crosslinked product of the perfluoroelastomer composition.

A thermoplastic resin composition including a fluororesin (A) and a crosslinked fluoroelastomer (B). The fluororesin (A) is a copolymer containing a chlorotrifluoroethylene unit and a tetrafluoroethylene unit and having at least one functional group selected from a carbonyl group, an olefinic group and an amino group at a main chain terminal or side chain terminal of the polymer. The crosslinked fluoroelastomer (B) is obtained by subjecting a fluoroelastomer (b) to a dynamic crosslinking treatment along with a polyamine compound (c) having a thermal decomposition temperature of 210° C. or higher and a crosslinking accelerator (d) in the presence of the fluororesin (A) under conditions for melting the fluororesin (A). Further, a mass ratio between the fluororesin (A) and the fluoroelastomer (b) (fluororesin (A)/fluoroelastomer (b)) is less than 70/30 and 20/80 or more. Also disclosed is a method for producing the composition as well as various molded and laminated products formed therefrom.

A composition having excellent scorch resistance and storage stability, the composition containing composite particles and a fluoropolymer, and the composite particles including a polymer and inorganic particles dispersed in the polymer.

A gasket material to be mounted in a vehicle engine, wherein, on one or both sides of a steel plate, a rubber layer is formed via a coating film including a reaction product of an acid component and a metal or a reaction product of an acid component and a metal compound, and at least one selected from zirconia, alumina and titania.

A composition including a fluorine-containing polymer and a cross-linking agent, wherein the fluorine-containing polymer contains a vinylidene fluoride unit, a unit of a fluorine-containing monomer (1) represented by the following general formula (1):

CHX.sup.1═CX.sup.2Rf   (1) wherein one of X.sup.1 and X.sup.2 is H, the other is F, and Rf is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms, and a unit of a monomer providing a crosslinking site. The monomer providing a crosslinking site is a monomer having at least one crosslinkable group selected from a cyano group, a carboxyl group, an alkoxycarbonyl group and a hydroxyl group. Also disclosed is a crosslinked rubber molded article obtained by crosslinking the composition.