A formed body including: a polytetrafluoroethylene or a modified polytetrafluoroethylene; and an unmodified polymerization inhibitor, the content of the unmodified polymerization inhibitor being 0.02 to 15 wt %.

A fluorine-containing elastomer composition comprising 0.4 to 4.0 parts by weight of a pigment that is a perylene-based compound, a naphthalenecarboxamide-based compound, a pyrimidinetrione-based compound, or a benzimidazolone-based compound, and 0.2 to 5.0 parts by weight of a bisamidoxime compound or 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, based on 100 parts by weight of a fluorine-containing elastomer having a copolymer composition of (A) 60.0 to 80.0 mol % of tetrafluoroethylene, (B) 19.8 to 39.8 mol % of perfluoro(lower alkyl vinyl ether) or perfluoro(lower alkoxy lower alkyl vinyl ether), and (C) 0.2 to 5.0 mol % of a perfluoro unsaturated nitrile compound.

An uncrosslinked fluororubber composition contains a rubber component containing fluororubber as a main component, ionic liquid, and an organic resin filler other than perfluoro resin.

Described herein are fluoropolymer compositions comprising a bis phthalonitrile-containing compound. In one embodiment, the bis phthalonitrile-containing compound is used to crosslink a dehydrohalogenated polymer, and optionally with a polyhydroxy curative. In another embodiment, the bis phthalonitrile-containing compound is added to a composition comprising (i) a fluorinated elastomeric gum, wherein the fluorinated elastomeric gum comprises a fluoropolymer having a cure-site and (ii) a peroxide curing system.

The present invention provides a seal comprising an elastomeric composite, said composite comprising an elastomeric polymer and a negative thermal expansion (NTE) filler, the NTE filler has a coefficient of thermal expansion (CTE) lower than ?6?10-6 K-1 within a temperature range of 220-293 K and is present in an amount of 0.01-50 volume % based on the total volume of the elastomeric composite at 20? C.

A material for gaskets is disclosed, wherein a metal surface coating layer, a primer layer and a rubber layer are formed, or a metal surface coating layer and a rubber layer are formed on at least a part of one side or both sides of a substrate formed of a metal plate sequentially from the metal plate side, and the metal surface coating layer comprises (A) one or more carbonates selected from the group consisting of Mg carbonate, Co carbonate, Zr carbonate, Mn carbonate, Ni carbonate, and Cu carbonate and (B) one or more selected from the group consisting of silica, alumina, zirconia, and titania.

A formed body including: a polytetrafluoroethylene or a modified polytetrafluoroethylene; and an unmodified polymerization inhibitor, the content of the unmodified polymerization inhibitor being 0.02 to 15 wt %.

A composition containing a fluorine-containing polymer and a silicon oxide represented by formula: SiO.sub.x, where 0<x<2. In a preferred embodiment, the composition contains a cross-linking agent. Also disclosed is a crosslinked product which may be a sealing material obtained by crosslinking the composition.

A composition comprising 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. ##STR00001##

A fluororubber composition in which fluororubber is compounded with triiron tetraoxide having a BET specific surface area of 4.0 m.sup.2/g or less at a ratio of 7.0 vol % or more as a volume fraction. A crosslinked product obtained by the fluororubber composition according to the present invention can be detected 1 mm pieces thereof by using a metal detector ND-840, produced by Nissin Electronics Co., Ltd., under the detection sensitivity conditions (Fe: 0.6 in diameter, SUS: 1.5 in diameter). Further, the compression set of the crosslinked product using an O-ring at 175 C. after 70 hours is 21% or less, and thus the crosslinked product can be effectively used for gaskets, O-rings, and the like for food production facilities, food machinery, automobiles, etc.