USE OF SURFACTANTS WITH HIGH MOLECULAR WEIGHT AS FILTERABILITY-ENHANCING AGENTS IN HYDRAULIC LUBRICANTS

摘要

The invention concerns a lubricating fluid comprising: 1) a predominant amount of oil with appropriate lubricating viscosity; and 2) between 0.03 % and 0.06 % of a filterability-enhancing agent corresponding to the following formula: R-Z in which Z represents: (i) a succinic ester acid comprising the reaction product of succinic anhydride and an aliphatic polyhydric alcohol; or (ii) a succinimide comprising the reaction product of succinic anhydride and a polyamine, said reaction product being subjected to a postcure with a cyclic carbonate, boric acid or a boric acid derivative; and R represents a polyolefin having a molecular weight (Mn) of 500 to 2500 and a Mw/Mn ratio of 1 to 5. This fluid is particularly suitable for hydraulic systems and has improved filterability characteristics.