| 摘要 |
<p>A seal ring made of polytetrafluoroethylene of 25 to 35% in crystallinity, not damaged for long time even in service under high pressure, excellent in durability, small in diameter variation rate, and excellent in easiness of mounting, whereby a stable sealing effect can be provided for long period and, particularly, the suitable characteristics of an endless type seal ring can be provided.</p> |
