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.
本发明提供了一种密封环,该密封环在长期使用过程中的高压滑动下具有很高的耐久性,而且非常适合安装。该密封环可以长期稳定地提供密封油的效果,并具有特别适合无端型密封环的特性。
带有滑动表面的密封环是通过将含有 0.01 至 1%(重量)由式(I)表示的
全氟乙烯基醚单 位的非熔模改性聚
四氟乙烯的模塑粉末或颗粒粉末进行模塑而获得的:
-
CF2-CF(-O-X)-(I)
其中 X 代表具有 1 至 6 个碳原子的
全氟烷基或具有 2 至 9 个碳原子的
全氟烷氧基,用差示扫描量热计测量,所述改性聚
四氟乙烯的结晶热为 18 至 25 焦耳/克。