| 摘要 |
PROBLEM TO BE SOLVED: To provide a lubricant that comprises a base oil of reduced degree of hydrorefining, solvent-dewaxed base oil and Zn DTP and is long-lived nevertheless, resistant to sludge formation by thermal and oxidative deterioration. SOLUTION: Use of the lubricant containing (a) 100 pts.wt. of mineral oil and/or synthetic oil, (b) 0.05-0.3 pt.wt. of a zinc salt of dithiophosphoric acid bearing two hydrocarbon groups calculated as the weight of Zn, (c) 0.1-3 pts.wt. of a phosphorus antioxidant only or a combination thereof with a phenolic antioxidant, (d) 0.1-2 pts.wt. of a dispersant and (e) 0.1-2 pts.wt. of a thiophosphate bearing three hydrocarbon groups can inhibit the occurrence of sludge for a long period of time. |
