Patent ID: 8338519

Claim:
A PTFE resin composition for use as a molding material of a seal ring against a metal having a rough surface to be polished as a mating material which consists of polytetrafluoroethylene (PTFE) resin molding powder consisting of at least one of tetrafluoroethylene homopolymer, tetrafluoroethylene copolymer having fluoroalkyl group on a side chain and tetrafluoroethylene-ethylene copolymer, tungsten carbide (WC) having a Vickers hardness of 1,200HV or more, and an inorganic fibrous filler, wherein the tungsten carbide imparts a polishing function to the PTFE resin so that when used as a molding material of a seal ring against a metal having a rough surface, the PTFE resin polishes that rough surface.