| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lubricating oil which is used for a refrigerator using ammonia as the refrigerant and is excellent in compatibility with ammonia and in dispersing sludge. SOLUTION: This lubricating oil comprises at least one cyclic amide derivative which is represented by general formula (1) (A is a 2-4C alkylene; R is H, a 1-6C alkyl, or a specific cyclic amide derivative group; m1 and m2 are each an integer of 1-66; and n1 and n2 are each an integer of 1-5) and has a number average mol.wt. of 200-3,000. |
