| abstract |
The refrigerator oil of the present invention is a refrigerator oil containing an ester of a polyhydric alcohol and a fatty acid, wherein the molar ratio of the fatty acid having 4 to 6 carbon atoms to the branched fatty acid having 7 to 9 carbon atoms in the fatty acid is 15:85 to 90:10, The fatty acid having 4 to 6 carbon atoms contains 2-methylpropanoic acid, and the total ratio of the fatty acid having 4 to 6 carbon atoms and the branched fatty acid having 7 to 9 carbon atoms in the total amount of the fatty acids constituting the ester is 20 mol% . Further, the working fluid composition for a refrigerator of the present invention contains the refrigerator oil and a difluoromethane refrigerant and / or an unsaturated fluorohydrocarbon refrigerant. |