Abstract: It is provided an ester for a refrigerator oil and of mixed alcohols and mixed monocarboxylic acids. The mixed alcohols include dipentaerythritol and tripentaerythritol in a mass ratio of 90/10 to 99.7/0.3, and the mixed monocarboxylic acids include n-pentanoic acid and 2-methyl butanoic acid in a mass ratio of 50/50 to 80/20. The ester has a kinematic viscosity of 50 to 150 mm2/s at 40° C.

Abstract: It is provided an ester for a refrigerator oil and of mixed alcohols and mixed monocarboxylic acids. The mixed alcohols include dipentaerythritol and tripentaerythritol in a mass ratio of 90/10 to 99.7/0.3, and the mixed monocarboxylic acids include n-pentanoic acid and 2-methyl butanoic acid in a mass ratio of 50/50 to 80/20. The ester has a kinematic viscosity of 50 to 150 mm2/s at 40° C.

Abstract: The present invention relates to an ester for refrigerator oils having less remaining by-products in the ester and having high thermal stability, and a method for producing the ester for refrigerator oils. The ester for refrigerator oils is obtained by treating a crude ester product, which is obtained by reacting a neopentyl polyol having a carbon number of 5 to 10 with an aliphatic carboxylic acid having a carbon number of 4 to 12, with one or more kinds of salts selected from the group consisting of sulfite, bisulfite, and pyrosulfite.

Abstract: The present invention relates to an ester for refrigerator oils having less remaining by-products in the ester and having high thermal stability, and a method for producing the ester for refrigerator oils. The ester for refrigerator oils is obtained by treating a crude ester product, which is obtained by reacting a neopentyl polyol having a carbon number of 5 to 10 with an aliphatic carboxylic acid having a carbon number of 4 to 12, with one or more kinds of salts selected from the group consisting of sulfite, bisulfite, and pyrosulfite.

Abstract: A refrigeration lubricant composition contains an ester compound obtained from a polyol and a fatty acid, and a five- or six-membered ring cyclic ether compound having a side chain with an ester bonding. The content of the cyclic ether compound is adjusted to 0.01 to 5 parts by mass based on 100 parts by mass of the ester compound.

Abstract: The present invention provides a refrigeration lubricant composition that have necessary properties such as compatibility with a hydrofluorocarbon refrigerant, thermal stability, hydrolytic stability and low-temperature fluidity, and good lubricity, and has high stability under low temperature conditions so that crystals are prevented from being precipitated over a long term. The refrigeration lubricant includes an ester obtained from a mixed alcohol and a mixed carboxylic acid, wherein the mixed alcohol consists of 65 to 99.95 mol % of pentaerythritol and 0.05 to 35 mol % of dipentaerythritol, the mixed carboxylic acid consists of n-pentanoic acid, n-heptanoic acid, and isononanoic acid, the molar ratio of the n-pentanoic acid to the n-heptanoic acid is 0.3 or more and 10 or less, and the isononanoic acid is contained in the mixed carboxylic acid at a ratio of 10 mol % or more and 45 mol % or less.

Abstract: A refrigeration lubricant composition contains an ester compound obtained from a polyol and a fatty acid, and a five- or six-membered ring cyclic ether compound having a side chain with an ester bonding. The content of the cyclic ether compound is adjusted to 0.01 to 5 parts by mass based on 100 parts by mass of the ester compound.

Abstract: The present invention provides a refrigeration lubricant composition that have necessary properties such as compatibility with a hydrofluorocarbon refrigerant, thermal stability, hydrolytic stability and low-temperature fluidity, and good lubricity, and has high stability under low temperature conditions so that crystals are prevented from being precipitated over a long term. The refrigeration lubricant includes an ester obtained from a mixed alcohol and a mixed carboxylic acid, wherein the mixed alcohol consists of 65 to 99.95 mol % of pentaerythritol and 0.05 to 35 mol % of dipentaerythritol, the mixed carboxylic acid consists of n-pentanoic acid, n-heptanoic acid, and isononanoic acid, the molar ratio of the n-pentanoic acid to the n-heptanoic acid is 0.3 or more and 10 or less, and the isononanoic acid is contained in the mixed carboxylic acid at a ratio of 10 mol % or more and 45 mol % or less.