| abstract |
A lubricant oil composition comprising a minor portion of calcium sulfonate(s), barium sulfonate(s), or mixture thereof being neutral or having the total base number of 100 mg KOH/g or less, and straight chain univalent fatty acid(s) having 8 to 18 carbon atoms and a major portion of a base oil of mineral oil series and/or synthetic oil series, said base oil having a kinematic viscosity of 10 to 50 mm2/s at 40 DEG C. The lubricant oil composition of the present invention exerts excellent separation properties from a cutting fluid prepared by diluting a water-soluble cutting fluid. Therefore, the composition so readily separates and floats in a reservoir tank for the cutting fluid that the composition can be removed simply by means of an oil skimmer and the like. Thus, the properties of the water-soluble cutting fluid can be maintained for a long term, with no occurrence of poor work environment due to rot and so on. |