| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lubricating oil composition having excellent oxidation stability and sludge production preventing property, free from lowering of oxidation stability even if used for a long time at a high temperature and useful for turbine oil, etc., by blending a lubricant base oil with a specific phenol compound and a nitrogen-containing compound. SOLUTION: This lubricating oil composition is obtained by blending (A) 100 pts.wt. lubricant base oil with (B) 0.1-5 pts.wt. compound of formula I (R<1> is a 1-4C alkyl; R<2> is a 1-24C alkyl or alkenyl) and (C) 0.001-1 pt.wt. nitrogen- containing compound selected from thiadiazole (C1 ) such as a compound of formula II [R<3> is a 1-30C (branched) alkyl; R<4> is H; (a) and (b) are each 1-3], a benzotriazole (derivative) (C2 ) such as a compound of formula III [R<5> is a 1-4C (branched) alkyl or H; C is 1-3] or a benzothiazole (C3 ) such as a compound of formula IV [R<10> is a 1-4C (branched) alkyl; R<11> is a 1-30C (branched) alkyl; (e) is 0-3; (f) is 1-3]. |
