US Patent 7914697 Refrigerating machine oil composition

The refrigerating machine oil composition of the invention is characterized by containing a mixed base oil which has a kinematic viscosity at 40° C. of 0.11 to 8 mm2/s and which is composed of a low-viscosity base oil (A) having a kinematic viscosity at 40° C. of 5 mm2/s or lower, and a high-viscosity base oil (B) having a kinematic viscosity at 40° C. of 20 to 400 mm2/s, each of the base oil (A) and (B) being composed of at least one species selected from among a mineral oil, a synthetic hydrocarbon compound, an oxygen-containing compound, and a sulfur-containing compound. The refrigerating machine oil composition exhibits enhanced energy saving performance by virtue of its low viscosity, has excellent sealing performance and load resistance, and can be employed in various refrigeration means, particularly suitably in a closed-type refrigerator.