| 摘要 |
PURPOSE:To obtain the title composition which can prevent the corrosion of piston sealing material, does not cause leakage of a hydraulic fluid, and enables long-term stable utilization of a power steering operation by using a specified phosphate compound and a specified thiazole derivative as constituents. CONSTITUTION:The title composition comprises at least one compound selected from groups of compounds, i.e., an alkyl, alkyl-substituted or unsubstituted phenyl phosphate compound, an alkyl, alkyl-substituted or unsubstituted phenyl thiophosphate compound, and an alkyl, alkyl-substituted or unsubstituted phenyl dithiophosphate compound (e.g. trilauryl phosphate); and a thiadiazole derivative of the formula (wherein R1 and R2 are each 1-12C alkyl) [e.g. 2,5-bis(t- octyldithio)-1,3,4-thiadiazole]. This composition can prevent corrosion damage to sealing material for a piston of a power cylinder, which has been a problem that could not be solved before; it does not cause leakage of a hydraulic fluid and it can ensure long-term stable utilization of power steering operation. |
