| abstract |
A synthetic lubricating oil based on an aliphatic polyester derivative having repeating units represented by general formula (I), wherein R?1 and R2¿ are as defined in the specification, and a molecular weight of 300 to 2000. This lubricating oil is excellent in the compatibility with a refrigerant and in the lubricity, which renders it suitable as a lubricating oil for a refrigerator, particularly a compression refrigerator. |