| 摘要 |
PROBLEM TO BE SOLVED: To provide a lubricating oil for a refrigerator using ammonia as a refrigerant having excellent compatibility with the ammonia and sludge dispersibility. SOLUTION: The lubricating oil for the refrigerator using the ammonia as the refrigerant comprises a cyclic ether derivative (A) represented by formula (1) [wherein R2 is hydrogen, a 1-6C alkyl group, a group represented by formula (2); (in the formulas (1) and (2), A is a 2-4C alkylene group; m1 is an integer of 0 or 1-66; m2 is an integer of 0 or 1-66; k is an integer of 1-4; R3 and R4 are each a single bond or a 1-10C alkylene group, and the sum of (a) carbon number(s) of R3 and R4 is 3-10; R5 is a single bond or a 1-4C alkylene group; and R6 is hydrogen or a 1-4C hydrocarbon group)], and an HLB value of the derivative (A) being >=5.6. |
