Abstract: A PTFE resin composition, which comprises PTFE resin, and metal carbide powder having a Vickers hardness of 1,200 HV, or more, and which preferably further contains an inorganic filler other than the metal carbide powder, for example, carbon fibers, glass fibers, etc., has an improved abrasion resistance, when molded into resin seal rings, etc., by reducing a self-abrasion amount of the resin against hard mating metals having a rough surface (Rz of about 6.3 to about 9.0 according to JIS B0601-1994), and by polishing the mating material roughness rapidly.

Abstract: A PTFE resin composition, which comprises PTFE resin, and metal carbide powder having a Vickers hardness of 1,200HV, or more, and which preferably further contains an inorganic filler other than the metal carbide powder, for example, carbon fibers, glass fibers, etc., has an improved abrasion resistance, when molded into resin seal rings, etc., by reducing a self-abrasion amount of the resin against hard mating metals having a rough surface (Rz of about 6.3 to about 9.0 according to JIS B0601-1994), and by polishing the mating material roughness rapidly.

Abstract: A seal ring which maintains a stable sealing performance over a long term is provided. In a first seal portion, linear contact portions which come into linear contact with the sidewall surface of an annular groove on the unsealed fluid side are continuously extended over the whole circumference of the seal ring from one side of a separation portion to the other side thereof, and the linear contact part provided at the convex part of the separation portion, and the linear contact part provided at the concave part of the separation portion are located at a distance in the radial direction of the seal ring.

Abstract: A seal ring which maintains a stable sealing performance over a long term is provided. In a first seal portion 4, linear contact portions which come into linear contact with the sidewall surface of an annular groove on the unsealed fluid side are continuously extended over the whole circumference of the seal ring from one side of a separation portion 2 to the other side thereof, and the linear contact part provided at the convex part 21 of the separation portion 2, and the linear contact part provided at the concave part 24 of the separation portion 2 are located at a distance in the diametric direction of the seal ring.

Abstract: An electroconductive resin composition, which comprises a thermosetting resin as a matrix and 40 to 90% by weight, on the basis of the composition, of carbon fibers and graphite as fillers, has a high electroconductivity and is suitable for use as a molding material for fuel cell separators. By using a molding material comprising phenol resin as a matrix and at least one kind of carbon fibers and graphite being coated by an electroconductive metal and molding fuel cell separators from the molding material, followed by post-curing at 130 to 300° C., fuel cell separators with a stable power generation capacity can be obtained.

Abstract: An electroconductive resin composition, which comprises a thermosetting resin as a matrix and 40 to 90% by weight, on the basis of the composition, of carbon fibers and graphite as fillers, has a high electroconductivity and is suitable for use as a molding material for fuel cell separators. By using a molding material comprising phenol resin as a matrix and at least one kind of carbon fibers and graphite being coated by an electroconductive metal and molding fuel cell separators from the molding material, followed by post-curing at 130 to 300° C., fuel cell separators with a stable power generation capacity can be obtained.