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.

Lubricant compositions comprising an oil of lubricating viscosity and a viscosity modifier that is a hydrocarbon polymer having a number average molecular weight (M.sub.n) of less than 10,000 Daltons (Da). The viscosity modifier is present at greater than 2 wt %, based on a total weight of the lubricant composition. Exemplary hydrocarbon polymers include, but are not limited to, olefin polymers, such as polyisobutylene polybutene, ethylene ?-olefin copolymers, or combinations thereof.

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 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.

A refrigerator oil according to one embodiment of the present invention contains: a base oil containing an oxygen-containing organic compound; a polyphosphate ester compound; and a metal salt of an organic carboxylic acid having 6 to 60 carbon atoms.

A refrigerator oil according to one embodiment of the present invention contains: a base oil containing an oxygen-containing organic compound; a polyphosphate ester compound; and a benzotriazole compound.

This invention relates to the use of chloro-trifluoropropenes as refrigerants in negative-pressure liquid chillers and methods of replacing an existing refrigerant in a chiller with chloro-trifluoropropenes. The chloro-trifluoropropenes, particularly 1-chloro-3,3,3-trifluoropropene, have high efficiency and unexpectedly high capacity in liquid chiller applications and are useful as more environmentally sustainable refrigerants for such applications, including the replacement of R-123 and R-11.

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.