REFRIGERATOR OIL, AND WORKING FLUID COMPOSITION FOR REFRIGERATORS

摘要

A refrigerator oil according to the present invention comprises a polyalkylene glycol represented by general formula (1): R1-(OR3)n-OR2 [wherein R1 and R2 may be the same as or different from each other and independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an acyl group having 2 to 5 carbon atoms; R3 represents an alkylene group having 2 to 4 carbon atoms; and n represents such an integer that the polyalkylene glycol represented by general formula (1) can have a number average molecular weight of 1000 to 2500], has a ratio of the weight average molecular weight (Mw) thereof to the number average molecular weight (Mn) thereof, i.e., Mw/Mn, of 1.00 to 1.15, and can be used together with a mildly flammable hydrofluorocarbon cooling medium.