LUBRICATING OIL FOR COMPRESSION-TYPE FREEZER

摘要

PROBLEM TO BE SOLVED: To obtain the subject lubricating oil having excellent compatibility with a hydrofluorocarbon-mixed cooling medium and excellent in stability, etc., by compounding a polyvinyl ether compound having a specific constituent unit as a main component. SOLUTION: This lubricating oil contains (A) a polyvinylether compound having a constituent unit of formula I (R is a 1-3C hydrocarbon group and may contains an ether bonding in a molecule) or (B) a polyvinyl ether compound having a constituent unit of formula I and that of formula II (R' is a 3-20C hydrocarbon group and may have an ether bonding in a molecule) as a main component. A cooling medium having compatibility with the lubricating oil is preferably a hydrofluorocarbon-based cooling medium containing pentafluoroethane in an amount of 20-80wt.%.