| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic operating oil composition excellent in sludge resistance, inhibiting the discoloration or corrosion of a metal material such as a copper material, etc., and also inhibiting the sliding resistance elevation caused by the sludge. SOLUTION: This hydraulic operating oil composition is provided by incorporating (A) 0.001 to 0.5 mass% metal salt of phosphorus-containing acid represented by general formula (a) or (b) as the amount of the metal (Z) based on the total amount of the composition and (B) 0.001 to 5 mass% amine-based antioxidant to at least 1 kind of the base oil of the lubrication oil selected from mineral oil-based base oil, synthetic base oil, and oils and fats. COPYRIGHT: (C)2009,JPO&INPIT |
