| 摘要 |
PROBLEM TO BE SOLVED: To provide an industrial hydraulic oil excellent in thermal oxidation stability, a sludge generation inhibiting effect, demulsibility and abrasion resistance of a hydraulic pump while reducing the blended amount of ZnDTP, which is a load resistant additive and an antioxidant.SOLUTION: There is provided an industrial hydraulic oil composition containing (A) a base oil, (B) primary zinc dialkyldithiophosphate of 0.01 to 0.5 mass%, (C) perbasic metal phenate of 0.03 to 1 mass%, and (D) phosphorous ester of 0.005 to 0.1 mass%, and having the content of a zinc component in the composition of 100 to 500 mass ppm and a mass ratio of a phosphorus component/a zinc component in the composition of 0.75 to 2.0.SELECTED DRAWING: None |
