| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lubricating oil compsn. for internal combusting engine, excellent in oxidation stability against NOx, material adaptability, shear stability, and which has a long life even used in an engine exposed to a high temp. blow-by gas contg. nitrogen oxides (NOx) gas. SOLUTION: This lubricating oil compsn. for internal combustion engine is manufactured by compounding with a base oil for lubricating oil comprising a mineral oil and/or a synthetic oil (A), a succinic imide (B) contg. boron of 0.005-0.06 wt.% as boron quantity (based on the total compsn.), 0.5-4.0 wt.% over basis metal phenate (C), 0.5-4.0 wt.% over basic metal sulfonate (D), and 0.5-10.0 wt.% olefin copolymer having a wt. average mol.wt. of 4.5×104-1.0×105. Total base number of the compsn. is 7-11 mg KOH/g, and the total base number coming from the component (C) is 10-40% of the total base number coming from the components (C) and (D). |
