| 摘要 |
A seal ring seals operating oil hermetically and is attached to an annular seal ring groove provided on an outer circumference of a shaft member. The seal ring comprises fluororesin, metal powder having a hardness equal to or more than that of any of a side surface of the seal ring groove serving as a sliding partner and an inner circumferential surface of a housing engaged relatively rotatable with the outer circumference of the shaft member, and modified fluororesin formed by irradiating an ionizing radiation in a range from 1 kGy to 10 MGy inclusive in a state of being heated up to a melting point thereof or higher under an inert gas atmosphere with an oxygen partial pressure of 1.33 kPa or less. |
