Synthetic refrigeration oil composition for HFC applications

1. A refrigeration composition comprising:

at least one ester, each of the at least one esters formed by esterification of only two components: a hydroxycarboxylic acid component and an alcohol component, the hydroxycarboxylic acid component selected from the group consisting of hydroxycarboxylic acids comprising more than one carboxylic acid group, hydroxystearic acid, hydroxylauric acid, hydroxydecanoic acid, hydroxyarachidic acid, hydroxypalmitic acid, hydroxylinoleic acid, hydroxyerucic acid, hydroxyarachidonic acid, ricinoleic acid, and combinations thereof, and the alcohol component comprising a polyalkylene glycol; and

a base oil lubricant selected from the group consisting of alkylbenzenes, alkylated naphthenics, polyalkylene glycols, polyvinylethers, polyalphaolefins, mineral oils, polyol esters, and combinations thereof.

2. The refrigeration composition of claim 1 comprising at least two esters formed by esterification of only two components.

3. The refrigeration composition of claim 1 further comprising an ester of a fatty acid.

4. The refrigeration composition of claim 3 , wherein the ester of a fatty acid comprises a 2-ethylhexanoic acid ester.

5. The refrigeration composition of claim 1 comprising from about 1% by weight to about 60% by weight of the at least one ester.

6. The refrigeration composition of claim 1 , wherein the base oil lubricant is miscible with a hydrofluorocarbon refrigerant.

7. The refrigeration composition of claim 1 , wherein the base oil lubricant is immiscible with a hydrofluorocarbon refrigerant.

8. The refrigeration composition of claim 1 , wherein the base oil lubricant comprises a combination of a compound that is miscible with hydrofluorocarbon refrigerant and a compound that is immiscible with a hydrofluorocarbon refrigerant.

9. The refrigeration composition of claim 1 further comprising a refrigerant selected from the group consisting of R134a, R125, R32, R23, R143a, R116, R152a, and combinations thereof.

10. The refrigeration composition of claim 1 , wherein the at least one ester is a monoester.

11. The refrigeration composition of claim 1 , wherein the at least one ester has a kinematic viscosity at 40° C. that is in the range of from about 24 to about 27 centistokes.

12. A refrigeration composition comprising:

an ester formed by esterification of only two components: a hydroxycarboxylic acid component selected from the group consisting of hydroxycarboxylic acids comprising more than one carboxylic acid group, hydroxystearic acid, hydroxylauric acid, hydroxydecanoic acid, hydroxyarachidic acid, hydroxypalmitic acid, hydroxylinoleic acid, hydroxyerucic acid, hydroxyarachidonic acid, ricinoleic acid, and combinations thereof, and an alcohol component comprising a polyalkylene glycol, wherein the ester has an alkoxylate portion which comprises one or more oxide monomers higher than ethylene oxide; and

a base oil lubricant selected from the group consisting of alkylbenzenes, alkylated naphthenics, polyalkylene glycols, polyvinylethers, polyalphaolefins, mineral oils, polyol esters, and combinations thereof.

13. The refrigeration composition of claim 12 , wherein the hydroxycarboxylic acid component comprises from 8 to 22 carbons.

14. The refrigeration composition of claim 12 , wherein the hydroxycarboxylic acid component comprises more than one carboxylic acid group.

15. The refrigeration composition of claim 14 , wherein the hydroxycarboxylic acid component is selected from the group consisting of citric acid, malic acid, tartaric acid, and combinations thereof.

16. The refrigeration composition of claim 12 , wherein the ester has a kinematic viscosity at 40° C. that is in the range of from about 24 to about 27 centistokes.

17. The refrigeration composition of claim 12 , wherein the ester is a monoester formed by esterification of a 1:1 molar ratio of the hydroxycarboxylic acid component to the alcohol component.