A working fluid composition for a refrigerating machine, containing: a refrigerant containing trifluoroiodomethane; and a refrigerating machine oil containing a complex ester synthesized from a polyhydric alcohol, a polybasic acid, and at least one selected from a monohydric alcohol and a monocarboxylic fatty acid.

An aspect of the present invention provides a refrigerating machine oil containing an ester-based base oil, at least one epoxy compound selected from an alkyl glycidyl ether and an aryl glycidyl ether, and a phenol-based antioxidant, wherein a content of the epoxy compound is 0.7% by mass or more based on a total amount of the refrigerating machine oil, and the refrigerating machine oil is used with a refrigerant containing trifluoroiodomethane.

The present invention provides a compressor for refrigeration and air conditioning and a refrigeration and air conditioning device capable of achieving both favorable environmental performance and favorable refrigeration cycle efficiency. In the compressor for refrigeration and air conditioning, a refrigerator oil containing a polyol ester and a refrigerant containing difluoromethane are enclosed. The polyol ester has two or more repetitions of poly[2,2-di(alkanoyloxymethyl)oxytrimethylene] as a structural unit. Further, the polyol ester is composed of only one or both of a cyclic polyol ester, which is obtained by cyclically polymerizing a molecular chain having the structural unit, and a crosslinked polyol ester, which is obtained by crosslinking molecular chains having the structural unit with each other through a crosslinkable structural unit polymerized with the structural unit.

Described herein are methods of stabilizing the beta hydrogen of glycerol based esters by the insertion of alkoxy groups to significantly improve the thermal, oxidative, and hydrolytic stability of the ester and allow for controlling the molar density of esters bonds in the lubricants to maximize hydrolytic stability while maintaining biodegradability and further improving performance properties.

A lubricant composition comprising an oil-soluble polyalkylene glycol; an ester compound selected from the group of natural esters and synthetic esters, and combinations thereof; and an additive mixture comprising an antioxidant and an anticorrosive, wherein the anticorrosive is selected from neutral alkali metal and alkaline earth metal salts of sulfonic acids, carboxylic acids, naphthoic acids, naphthenic acids, benzoic acids and phosphoric acids, and derivatives and combinations thereof.

The present invention provides a working fluid composition for a refrigerating machine, comprising: a refrigerating machine oil comprising, as a base oil, a mixed ester of (A) a complex ester obtainable by synthesis of at least one polyhydric alcohol selected from neopentyl glycol, trimethylolpropane and pentaerythritol, a C6-C12 polybasic acid, and a C4-C18 monohydric alcohol or a C4-C18 monocarboxylic fatty acid, and (B) a polyol ester obtainable by synthesis of at least one polyhydric alcohol selected from neopentyl glycol, trimethylolpropane, pentaerythritol and dipentaerythritol, and a C4-C18 monocarboxylic fatty acid, in a mass ratio of (A) the complex ester/(B) the polyol ester of 5/95 to 95/5; and a hydrocarbon refrigerant having 3 or 4 carbon atoms, wherein a refrigerant dissolved viscosity, at a temperature of 80° C. and an absolute pressure of 1.5 MPa, is 1.0 mm.sup.2/s or more.

The present invention provides a working fluid composition for a refrigerating machine, comprising: a refrigerating machine oil comprising, as a base oil, a mixed ester of (A) a complex ester obtainable by synthesis of at least one polyhydric alcohol selected from neopentyl glycol, trimethylolpropane and pentaerythritol, a C6-C12 polybasic acid, and a C4-C18 monohydric alcohol or a C4-C18 monocarboxylic fatty acid, and (B) a polyol ester obtainable by synthesis of from at least one polyhydric alcohol selected from neopentyl glycol, trimethylolpropane, pentaerythritol and dipentaerythritol, and a C4-C18 monocarboxylic fatty acid, in a mass ratio of (A) the complex ester/(B) the polyol ester of 5/95 to 95/5; and tetrafluoropropene as a refrigerant, wherein a refrigerant dissolved viscosity, at a temperature of 80° C. and an absolute pressure of 1.6 MPa, is 1.5 mm.sup.2/s or more.

A liquid anti-friction composition includes an ester product having a number average molecular weight that is greater than 3800 g/mol, and obtained by subjecting a mixture that includes diglycerol, a monobasic acid component, and a dibasic acid component to an esterification reaction. The monobasic acid component includes at least one C.sub.14-C.sub.24 branched chain fatty acid.

Described herein are methods of stabilizing the beta hydrogen of glycerol based esters by the insertion of alkoxy groups to significantly improve the thermal, oxidative, and hydrolytic stability of the ester and allow for controlling the molar density of esters bonds in the lubricants to maximize hydrolytic stability while maintaining biodegradability and further improving performance properties.

Described herein are methods of stabilizing the beta hydrogen of glycerol based esters by the insertion of alkoxy groups to significantly improve the thermal, oxidative, and hydrolytic stability of the ester and allow for controlling the molar density of esters bonds in the lubricants to maximize hydrolytic stability while maintaining biodegradability and further improving performance properties.