Patent ID: 7018961

Claim:
A refrigerator oil composition for carbon dioxide refrigerant, the refrigerator oil composition comprising a base oil and an acid scavenger, wherein the base oil comprises an oxygen-containing organic compound and has a kinematic viscosity at 100° C. of from 5 to 50 mm 2 / sec, a viscosity index of at least 60, and a water content of at most 300 ppm; the oxygen-containing organic compound is one or more selected from polyoxyalkylene glycols, polyvinyl ethers and carbonates; the acid scavenger is one or more selected from alkyl glycidyl ethers each comprising an alkyl group containing between 3 and 30 carbon atoms, alkylene glycol glycidyl ethers each comprising an alkylene group containing between 3 and 30 carbon atoms, and α-olefin oxides each containing between 4 and 30 carbon atoms; and the acid scavenger content of the refrigerator oil composition falls between 0.005 and 5% by weight relative to the base oil.