To provide a freezer oil composition excellent in lubricity, cooling medium compatibility, electric insulation, etc., and also enabling the high efficiency of the freezing system in the case of using it together with a HFC (hydrofluorocarbon) and a natural-based cooling medium such as carbon dioxide and a hydrocarbon, etc.
This freezer oil is characterized by containing a trans type alicyclic dicarboxylic acid ester compound having an alicyclic type ring and two ester groups expressed by COOR1, bonding the two ester groups with carbon atoms adjacent each other on the alicyclic ring and being the trans-form concerning the orientation of two ester groups (R1 expresses a 1-30C hydrocarbon group, and R1's of each of the ester groups may be the same or different).
SUDA SATOSHI
HIRANO HIROYUKI
