| abstract |
PURPOSE:To obtain a refrigerator oil excellent in thermal stability in the atmosphere of a fluoroethane refrigerant and in lubricity by using an ester prepared from a specified aliphatic polyhydric alcohol, a specified saturated aliphatic monocarboxylic acid, and a specified saturated aliphatic dicarboxylic acid. CONSTITUTION:An ester prepared from an aliphatic polyhydric alcohol (A) having one to six primary hydroxyl groups (e.g. neopentyl glycol or trimethylolpropane), a 2-9C straight-chain or branched saturated aliphatic monocarboxylic acid or its derivative (B) (e.g. caprylic acid or caproic acid), and a 2-10C straight-chain or branched saturated aliphatic dicarboxylic or its derivative (C) (e.g. adipic acid or glutaric acid) is employed as a base oil to give a refrigerator oil used in the atmosphere of a hydrofluoroethane refrigerant. It is a refrigerator lubricating oil excellent in compatibility with the refrigerant, thermal stability in the atmosphere of the refrigerant, and lubricity. |