| 摘要 |
PURPOSE:To prepare a lubricating oil compsn. having excellent oxidation stability and low-temp. stability, by incorporating an antioxidant in a mineral oil which has a kinetic viscosity, an arom. content and a naphthene content each falling within a predetermined range, high viscosity index and high flocculation point. CONSTITUTION:0.001-10wt.% antioxidant (e.g., 2,6-di-tert-butyl-p-cresol) is incorporated in a mineral oil having a kinetic viscosity (40 deg.C) of 2-500cSt, an arom. content of 5% or less, a naphthene content of 30% or more, a viscosity index of 70 or more and a flocculation point of -25 deg.C or below. Thus, there is obtd. a lubricating oil compsn. which is excellent in the oxidation stability, forms no significant sludge even when used for a long period of time, and is excellent in the low-temp. working property. Therefore, the use of this compsn. can eliminate troubles such as failure of operation of valves such as a solenoid valve or a servo valve, and failure of starting of a machinery at a low temp. This renders this compsn. useful as a lubricating oil for each part of a generator, a compressor (particularly screw compressor), hydraulic equipment, a machine tool, etc. |
