| abstract |
A refrigerator oil comprises an ester obtained from:pentaerythritol; anda carboxylic acid mixture comprising n-pentanoic acid in an amount of 20 to 50% by mass; n-heptanoic acid in an amount of 20 to 50 % by mass and 3,5,5-trimethylhexanoic acid in an amount of 5 to 60 % by mass, of the total amount of the carboxylic acid mixture. |