| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lubricating oil composition having excellent abrasion resistance and high oxidation resistance in the presence of nitrogen oxides at high temperature, and continuing the low friction state and useful for an internal combustion engine by compounding a base oil with a specific zinc dithiophosphate mixture, a sulfur compound and a molybdenum compound. SOLUTION: This oil composition is produced by compounding a lubricating base oil with (A) a compound of formula I (R<1> to R<4> are each a 1-20C primary alkyl) (A1 ) and a compound of formula II (R<5> to R<8> are each a 3-7C secondary alkyl) (A2 ), (B) a sulfur compound such as zinc salt, copper salt, etc., of a di (2-18C alkyl) dithiocarbamic acid salt, tetra (2-18C alkyl) thiuram disulfide, a disulfide having a 2-18C alkyl group or a 3-24C thiadiazol compound substituted with an S-containing group and (C) a compound of formula III (R<9> to R<12> are each a 1-30C alkyl, etc.; X is O or S) or a compound of formula IV (R<13> to R<16> are each R<9> ) at an A1 /A2 weight ratio of (20-80):(80-20). The amounts the components A, B and C in the composition are 700-1,500ppm in terms of P, 300-1,200ppm in terms of S and 200-2,000ppm in terms of Mo, respectively. |
