| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic oil which has a high viscosity index and excellent shear stability and can realize the energy saving of a hydraulic system, and to provide a hydraulic system using the hydraulic oil. SOLUTION: This hydraulic oil is characterized by containing a mineral oil and/or a polyα-olefin as a base oil, and having a kinematic viscosity (40°C) of 10 to 600 mm<SP>2</SP>/s, a viscosity index of 140 to 200, a viscosity-lowering rate of≤0.5% at a high temperature and high shear time (TBS viscosity, 100°C), and a viscosity-lowering rate of≤0.5% in a shear stability test (JPI method). A hydraulic system uses the hydraulic oil. COPYRIGHT: (C)2008,JPO&INPIT |
