| abstract |
A refrigerating machine oil composition for carbon dioxide refrigerants whic h consists mainly of a mixture of (A) 40 to 99.1 wt.%, excluding 40 wt.%, polyvinyl ether having a dynamic viscosity at 100~C of 3 to 50 mm2/s and (B) 0.1 to 40 wt.%, excluding 40 wt.%, polyoxyalkylene glycol having a dynamic viscosity at 100~C of 3 to 50 mm2/s. It has satisfactory lubricating properties and a high viscosity index even in the presence of a refrigerant consisting mainly of carbon dioxide. The composition can be excellent in stability and lubricating properties and used over long even in an atmospher e of supercritical carbon dioxide, while retaining those features. |