The refrigeration oil composition comprises (1) a hydrogenated fluoroethane and (2) an ester compound obtained from (2-a) an aliphatic polyhydric alcohol having 1 to 6 primary hydroxyl groups, (2-b) a saturated aliphatic monocarboxylic acid having 2 to 9 carbon atoms, straight or branched, or a derivative thereof and (2-c) a saturated aliphatic dicarboxylic acid having 2 to 10 carbon atoms, straight or branched, or a derivative thereof, said ester compound having a kinematic viscosity at 100 degree C of 1 to 100 cst.  
                            该冷冻机油组合物包括(1)氢化
氟乙烷和(2)一种
酯类化合物,该
酯类化合物由(2-a)具有1至6个伯羟基的脂肪族多元醇、(2-b)具有2至9个碳原子的饱和脂肪族一元
羧酸、直链或支链、或其衍
生物和(2-c)具有2至10个碳原子的饱和脂肪族二元
羧酸、直链或支链、或其衍
生物得到、(2-c) 具有 2 至 10 个碳原子(直链或支链)的饱和脂肪族二
羧酸或其衍
生物,所述
酯类化合物在 100 摄氏度时的运动粘度为 1 至 100 cst。