| 摘要 |
PROBLEM TO BE SOLVED: To provide a refrigerator oil composition which exhibits an excellent lubricity in a freezing cycle using a refrigerant mainly comprising high- temperature high-pressure carbon dioxide in the supercritical state and can be stably used for a long term by compounding a base oil mainly comprising an oxygen-containing organic compound and having specified kinematic viscosity and viscosity index with a metal carboxylate. SOLUTION: A base oil mainly comprising an oxygen-containing organic compound represented by the formula: R1-[(OR2)m-OR3]n or by the formula and having a kinematic viscosity (100 deg.C) of 5-50 cSt and a viscosity index of 60 is compounded with 0.001-5 wt.% metal carboxylate. In the formulas, R1 is H, 1-10C alkyl, 2-10C acyl, or a 1-10C aliphatic hydrocarbon group having 2-6 bonding sites; R2 is 2-4C alkylene; R3 is H, 1-10C alkyl, or 2-10C acyl; n is 1-6; m is such a number that the mean value of m×n is 6-80; R16 to R18 are each H or a 1-8C hydrocarbon group; R19 is a 1-10C divalent hydrocarbon group; R20 is a 1-20C hydrocarbon group; and k is such a number that its mean value is 0-10. |
