Seal ring

Abstract

There is provided a seal ring which is excellent since the seal ring has a high durability under sliding at high pressure during a long-term use, and a necessary suitability for fitting. The seal ring can provide an effect of sealing oil stably for a long period of time, and possesses properties suitable particularly for a seal ring of endless type. The seal ring with a sliding surface, which is obtained by molding a molding powder or granulated powder of non-melt-moldable modified polytetrafluoroethylene containing 0.01 to 1% by weight of a perfluorovinylether unit represented by the formula (I): —CF2—CF(—O—X)—  (I) wherein X represents a perfluoroalkyl group having 1 to 6 carbon atoms or a perfluoroalkoxyalkyl group having 2 to 9 carbon atoms, said modified polytetrafluoroethylene having a heat of crystallization of 18 to 25 J/g measured by a differential scanning calorimeter.

Dependencies are inferred from the claim text.