| 摘要 |
PROBLEM TO BE SOLVED: To provide a gear oil composition for a car which shows excellence in oxidation stability at a high temperature, copper corrosion resistance, an extreme pressure property, abrasion resistance and a synchronizing property and is usable both for a manual speed change gear and a final reduction gear. SOLUTION: A base oil having kinematic viscosity of 2 to 80 mm2s at 100 deg.C contains, as essential components, (A) 0.1 to 10 wt.% of not less than one of dialkyl trisulfides represented by formula I, formula I: R1-S-S-S-R1 (wherein R1 is a hydrocarbon group) (B) 0.1 to 5 wt.% of not less than one of dithiophosphoric esters represented by general formula II formula II: (R2O)2P(=S) SR3 (wherein R2 and R3 are each a group independently selected from hydrocarbon groups) and (C) 0.1 to 5 wt.% of not less than one of phosphorus compounds selected from an acidic phosphate, a phosphite and an alkylamine salt thereof represented by formula III. formula III: (R4O)nP(=O)(OH)3-n (wherein R4 is a hydrocarbon group; and n is 1, 2 or 3). |
