| 摘要 |
PROBLEM TO BE SOLVED: To provide a refrigerator oil for a difluoromethane refrigerant which exhibits sufficiently high refrigerant compatibility and lubricity even when used together with a difluoromethane refrigerant, and also provide a fluid composition for a refrigerator prepared by using the same. SOLUTION: This refrigerator oil contains at least 50 mass% fatty acid esters of pentaerythritol. Fatty acids constituting the esters are characterized in that (a) the sum of contents of 5-6C linear fatty acids and 5-7C branched fatty acids is 10-80 mol%, (b) the content of 8-9C branched fatty acids is 20-90 mol%, and (c) the sum of contents of 5-6C linear fatty acids and 5-9C branched fatty acids is 80-100 mol%. The kinematic viscosity at 40 deg.C of the oil is 40-80 mm2/s. |
