| 摘要 |
PROBLEM TO BE SOLVED: To obtain a W/O emulsion type flame-retarded hydraulic oil having excellent heat stability and oxidation stability, not forming an inorganic solid deteriorated substance. SOLUTION: This W/O emulsion type flame-retarded hydraulic fluid is characterized in that the hydraulic fluid comprises (a) 0.2-10 wt.% of an alkenylsuccinimide type or an alkenylsuccinic acid ester type asheless cleaning dispersant, (b) >=20 wt.% of water and (c) >=40 wt.% of at least one kind of a mineral oil, oils and fats and a synthetic oil, uses any of an anionic, a cationic or a nonionic surfactant as an emulsifying agent, maintains an emulsion state of W/O emulsion and substantially does not contain (d) an inorganic cleaning dispersant represented by Ba sulfonate, Ca sulfonate or Mg sulfonate and a wear preventive containing a metal element represented by zinc dithiophosphate or its derivative. |
