| 摘要 |
PROBLEM TO BE SOLVED: To provide a seal method and a hydraulic system which can prevent oil leakage and employ harmless hydraulic oil with high oxidation stability.SOLUTION: A seal method preventing oil leakage in a hydraulic system including a seal member (1), employs, as hydraulic oil (30) of the hydraulic system, a fat composition containing 90 mass% or more triglyceride having middle chain fatty as constitutional fatty acid; and fluoride carbon resin as a material of a seal member. |
