| 摘要 |
PROBLEM TO BE SOLVED: To obtain a refrigerator oil excellent in compatibility with a refrigerant, lubrication, hydrolysis resistance, thermal stability and electric insulation by including pentaerythritol and an ester obtained from a specific carboxylic acid mixture. SOLUTION: This refrigerator oil comprises pentaerythritol and an ester obtained from a carboxylic acid mixture composed of 20-50 wt.% n-pentanoic acid, 20-50 wt.% n-heptanoic acid and 5-60 wt.% 3,5,5-trimethylhexanoic acid based on the total amount of the carboxylic acid mixture, preferably in a proportion of 90 wt.% (based on the total amount of the refrigerator oil). |
