| abstract |
Provided is a pressure transmission medium which contains, as a pressure transmission medium base oil, an ester or an ether having two or more aromatic rings or saturated naphthene rings. The pressure transmission medium is small in energy loss by compression, excellent in responsiveness when used in a hydraulic circuit, saving energy in the hydraulic circuit, increasing speed, improving the accuracy of control, having low viscosity and small agitating resistance, and saving energy. Also provided is a hydraulic device using the medium. |