| 摘要 |
PURPOSE: To prepare a lubricating oil compsn. comprising a base oil for lubricating oil, an Mo-contg. friction modifier and a B-contg. compd. which can reduce a coking deposit and, hence, can maintain low fuel consumption for a long period of time by limiting the Mo and B contents to respective particular ranges. CONSTITUTION: The Mo content of an Mo-contg. friction modifier is limited to 100 to 2000ppm (by weight) based on the total amt. of the compsn., and the B content of a B-contg. compd. is limited to not less than 0.015wt.%. Any base oil for lubrication oil may be used without limitation, and examples thereof include mineral oils and synthetic oils. In general, the kinematic viscosity at 100 deg.C is pref. 3 to 20mm<2> /sec. The Mo-contg. friction modifier is not particularly limited so far as it contains Mo and, when added to the lubricating oil, functions to lower the friction properties. Examples thereof include molybdenum oxysulfide dithiocarbamate, and B-contg. compds. for preventing coking deposit include, e.g. boron-contg. succinimide. When the Mo content is constant, the deposit preventive effect increases with an increasing B content. |
