| abstract |
PROBLEM TO BE SOLVED: To provide a refrigerating machine oil for a difluoromethane refrigerant having sufficiently high refrigerant compatibility and sufficiently high lubricity even when used together with a difluoromethane refrigerant, and a refrigerator using the same. Providing a fluid composition for use. SOLUTION: The refrigerating machine oil for difluoromethane refrigerant of the present invention contains an ester of pentaerythritol and a fatty acid in an amount of 50% by mass or more based on the total amount of the refrigerating machine oil. The sum of the ratio of the linear fatty acid having a carbon number of 6 to 6 and the ratio of the branched fatty acid having a carbon number of 5 to 7 is 10 to 80 mol% based on the total amount of the fatty acid, and (b) the ratio of the branched fatty acid having 8 to 9 carbon atoms is 20 to 90 mol% based on the total amount of fatty acids, and (c) the sum of the ratio of the straight-chain fatty acids having 5 to 6 carbon atoms and the ratio of the branched-chain fatty acids having 5 to 9 carbon atoms is 80 to 90% based on the total fatty acids. 10 0 mol%, and the kinematic viscosity at 40 ° C. is 40 to 8 0 mm 2 / s. |