abstract |
(57) [Summary] [Structure] An ester obtained from (a) an aliphatic polyhydric alcohol having 2 to 12 carbon atoms and (b) a saturated aliphatic monocarboxylic acid having 4 to 9 carbon atoms or a derivative thereof. And a composition for a refrigerator working fluid containing difluoromethane and a refrigerating machine oil comprising an ester having a ratio of the number of acyl groups having a branched chain to the total number of acyl groups in the ester of 95% or more. [Effect] Since the composition for a working fluid of a refrigerator of the present invention contains the above-mentioned ester, it is excellent in compatibility, lubricity and electric insulation and, in contrast to the conventional one, is particularly excellent in thermal stability. . |