The lubricating oil composition for a refrigerator of the present invention is used with a refrigerant containing carbon dioxide, and contains a base oil (A) containing a polyoxyalkylene glycol as a major component, and an alcohol (B) having at least one hydroxy group, in which a total number of the hydroxy group and an ether bond is from 2 to 3 (provided that the number of an ether bond may be 0).

The present invention relates to a refrigerator oil containing a polyvinyl ether-based compound (A) containing a structural unit (a1) having a methoxy group in a side chain thereof in an amount of 30 mol % or more and 100 mol % or less on a basis of 100 mol % of the whole amount of structural units excluding a terminal structural unit in a molecular structure thereof, a refrigerator oil composition containing the refrigerator oil, and a production method of the refrigerator oil.

A working fluid for use in a compression refrigeration, air conditioning or heat pump system, is described, which has a refrigerant composed of a fluoro-olefin, and a lubricant which is a mixture of polyol ester and a polyoxyalkylene glycol, and the polyol ester is present in an amount of at least 50% by weight based on the total weight of the polyol ester and the polyoxyalkylene glycol. A lubricant, being a mixture of a polyol ester and a polyoxyalkylene glycol, is described and comprises at least 10% by weight of polyoxyalkylene glycol based on the total weight of the polyol ester and the polyoxyalkylene glycol.

The present invention relates to a refrigerant composition, including trifluoroiodomethane (CF.sub.3I); 1,1,1,2-tetrafluoropropene (HFO-1234yf); difluoromethane (HFC-32); and carbon dioxide (CO.sub.2), for use in a heat exchange system, including refrigeration applications and in particular aspects to the use of such compositions as a replacement of the refrigerant R-404A for heating and cooling applications and to retrofitting heat exchange systems, including systems designed for use with R-404A.

Provided herein are compositions comprising at least one estolide compound of formula: ##STR00001##
in which n is an integer equal to or greater than 0; m is an integer equal to or greater than 1; R.sub.1, independently for each occurrence, is selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; R.sub.2 is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; and R.sub.3 and R.sub.4, independently for each occurrence, are selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched. Also provided are uses of the compositions described herein.

In accordance with a refrigerator oil including a polyphosphate ester-based compound, a polyhydric alcohol, and a base oil containing an oxygen-containing organic compound, it is possible to provide a refrigerator oil capable of reducing a coefficient of friction, a refrigerator oil composition, and a method for producing a refrigerator oil.

The working fluid composition for a refrigerating machine of the present invention comprises a refrigerant comprising a first refrigerant component and a second refrigerant component, and having a global warming potential (GWP) of 500 or less, wherein the first refrigerant component is at least one selected from difluoromethane and tetrafluoropropene, and the second refrigerant component is at least one selected from carbon dioxide and a hydrocarbon having 3 to 4 carbon atoms; and a refrigerating machine oil comprising at least one selected from a polyol ester, a polyvinyl ether arid a polyalkylene glycol compound as a base oil, wherein a carbon/oxygen molar ratio of the base oil is 2.5 or more and 5.8 or less.

The working fluid composition for a refrigerating machine of the invention is characterized by comprising an ester of a polyhydric alcohol and a fatty acid with a content of a C5-C9 branched fatty acid of 50-100% by mole, and a fluoropropene refrigerant and/or trifluoroiodomethane refrigerant. The refrigerating machine oil of the invention is characterized by comprising an ester of a polyhydric alcohol and a fatty acid with a content of a C5-C9 branched fatty acid of 50-100% by mole, and by being used together with a fluoropropene refrigerant and/or trifluoroiodomethane refrigerant.

The refrigerator oil according to the present invention includes a base oil including an oxygen-containing organic compound and a phosphorus-based compound represented by the following general formula (1). ##STR00001## In the formula (1), n represents an integer of 1 to 10; R.sup.1 to R.sup.8 each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and Ar represents a divalent hydrocarbon group having 2 to 20 carbon atoms.

Refrigerant compressor includes electromotive element, and compression element that is driven by electromotive element, includes a slider, and compresses a refrigerant. Freezer oil that lubricates the slider is added with fullerene having a diameter that ranges from 100 pm to 10 nm.