| 摘要 |
PURPOSE:To provide an incombustible hydraulic liquid of high-performance, suitable for the hydraulic system with precision control circuits, comprising a liquid paraffin, a nonion surfactant, and, as a thickening agent, a water-soluble polymer. CONSTITUTION:The objective hydraulic liquid comprising (1) a liquid paraffin with such a high-purity that a sulfur content in it is <=100ppm, (2) a nonion surfactant, and (3) a thickening agent for preventing leak and corrosion by increasing viscosity of the liquid. Said thickening agent is, pref., e.g., polyvinyl alcohol, polyacrylic acid (or its sodium salt), because of their outstanding thickening effect with a small amount of application and of being free from impairing the incombustibility of the liquid. The thrace amont of surfur present in the liquid leading to prevention of cavitation development due to its high viscosity enables the discoloration and/or corrosion of equipment materials to be negligibly low. |
