| abstract |
A refrigerating machine oil composition for refrigerants which comprises a composition comprising as an oil base (A) a polyoxyalkylene glycol having a dynamic viscosity at 100°C of 3 to 50 mm2/s and incorporated therein 0.1 to 40 wt.% at least either of (B) a carbonic acid carbonyl derivative and (C) a polyol ester each having a dynamic viscosity at 100°C of 3 to 50 mm2/s. In refrigeration cycles employing a refrigerant consisting mainly of supercritical carbon dioxide having a high temperature and high pressure, the refrigerating machine oil composition is excellent not only in wearing resistance and lubricity but in compatibility with the carbon dioxide refrigerant and can be stably used for long. |