Abstract: A refrigerating machine oil containing: a lubricating base oil; and a compound represented by the following formula (1): wherein R1 and R2 each independently represent a monovalent hydrocarbon group, R3 represents a divalent hydrocarbon group, and R4 represents hydrogen atom or a monovalent hydrocarbon group, and the refrigerating machine oil having a kinematic viscosity at 100° C. of 0.5 mm2/s or more and 2.5 mm2/s or less.

Abstract: The present invention provides a refrigerating machine oil comprising a hydrocarbon-based base oil having a viscosity index of 120 or less, and the refrigerating machine oil being used with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.

Abstract: A refrigerating oil comprising a lubricating base oil, a first extreme pressure agent containing sulfur and phosphorus as constituent elements and a second extreme pressure agent containing phosphorus but not containing sulfur as constituent elements, and having a kinematic viscosity at 100° C. of 0.5 mm2/s or more and 2.5 mm2/s or less.

Abstract: The present invention provides a refrigerating machine oil comprising a lubricating base oil and at least one selected from the group consisting of an amine salt of phosphonic acid and an amine salt of phosphonic acid monoester, and a method for producing the same.

Abstract: A working fluid composition for a refrigerating machine, containing: a refrigerant containing trifluoroiodometbane; and a refrigerating machine oil containing a polyol ester and a hindered phenol compound, wherein a content of the hindered phenol compound is 0.6 to 10% by mass based on a total amount of the refrigerating machine oil.

Abstract: 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.

Abstract: The present invention provides a refrigerating machine oil containing a lubricating base oil, a dialkyl hydrogen phosphite having two alkyl groups having 1 to 12 carbon atoms in the molecule, and an epoxy compound.

Abstract: A method for operating a refrigerant circulation system comprising a compressor, a condenser, an expansion mechanism, and an evaporator connected in this order with piping, wherein a refrigerant comprising trifluoroiodomethane is used as a refrigerant; a refrigerating machine oil comprising, as a base oil, a polyolester synthesized from a polyhydric alcohol and fatty acids, with a proportion of a fatty acid having 9 carbon atoms in the fatty acids being 65 mol % or less is used as a refrigerating machine oil; and a temperature of an entire area of the refrigerant circulation system is kept at 160° C. or lower.

Abstract: One aspect of the present invention is a refrigerating machine oil containing: a base oil containing an ester of an alcohol and a fatty acid; a compound represented by the following formula (1): wherein R1 and R2 each independently represent a monovalent hydrocarbon group, R3 represents a divalent hydrocarbon group, and R4 represents hydrogen atom or a monovalent hydrocarbon group, and the refrigerating machine oil having a kinematic viscosity at 40° C. of 10 mm2/s or less.

Abstract: One aspect of the present invention is a refrigerating machine including a refrigerant circulation system including a compressor, a condenser, an expansion mechanism, and an evaporator, and the refrigerant circulation system being filled with a refrigerant and a refrigerating machine oil, wherein the refrigerating machine oil contains: a first base oil having a compatible region with the refrigerant in a range of a temperature of 30° C. or lower and an oil ratio of 1 to 80% by mass; and a second base oil having a kinematic viscosity at 40° C. lower than the first base oil and having a narrower compatible region with the refrigerant than the first base oil.

Abstract: An aspect of the present invention relates to a refrigerating machine oil with a kinematic viscosity at 100° C. of 0.5 mm2/s or more and 1.5 mm2/s or less, a 90% distillation temperature in gas chromatography distillation of 280° C. or more and less than 360° C., and an aniline point of 70° C. or more.

Abstract: A refrigerating machine oil having a kinematic viscosity at 100° C. of 0.5 mm2/s or more and 2.5 mm2/s or less, a distillation end point in gas chromatography distillation of 380° C. or more and 450° C. or less, and a sulfur content of 0.001 mass % or more and 0.2 mass % or less.

Abstract: A lubrication method including lubricating a sliding member which contains at least one selected from the group consisting of a liquid crystal polymer and polyetheretherketone by using a lubricating oil composition which contains at least one selected from the group consisting of a mineral oil and alkyl benzene as a lubricating base oil.

Abstract: One aspect of the present invention is a refrigerating machine oil comprising a base oil, a dithiophosphoric acid ester, and a phosphonate ester.

Abstract: The present invention provides a method for producing a refrigerating machine oil, comprising blending a hydrocarbyl hydrogen phosphite having an acid value of 100 mgKOH/g or less with a lubricating base oil or an oil composition containing a lubricating base oil, and a refrigerating machine oil obtained by the method.

Abstract: The present invention provides a refrigerating machine oil comprising a lubricating base oil and at least one selected from the group consisting of an amine salt of phosphonic acid and an amine salt of phosphonic acid monoester, and a method for producing the same.

Abstract: One aspect of the present invention is a refrigerating machine oil comprising a base oil, a dithiophosphoric acid ester, and an amine salt of an acidic phosphoric acid ester.

Abstract: In an aspect, the present invention provides a refrigerating machine oil comprising a poly(meth)acrylate as a base oil, wherein the poly(meth)acrylate comprises a hydrogenated poly(meth)acrylate, a content of a unit having a carbon-carbon double bond present at a terminal in the poly(meth)acrylate is 6% by mole or less relative to total units constituting the poly(meth)acrylate, and a kinematic viscosity at 40° C. of the hydrogenated poly(meth)acrylate is 1 to 1000 mm2/s, the refrigerating machine oil being used with a refrigerant comprising a refrigerant selected from difluoromethane, a mixture of difluoromethane and pentafluoroethane, a mixture of difluoromethane, pentafluoroethane, and 1, 1, 1, 2-tetrafluoroethane, a mixture of pentafluoroethane, 1, 1, 1, 2-tetrafluoroethane, and 1, 1, 1-trifluoroethane, an unsaturated hydrofluorocarbon, a hydrocarbon, and carbon dioxide.

Abstract: The present invention provides a refrigerating machine oil containing a lubricating base oil, a dialkyl hydrogen phosphite having two alkyl groups having 1 to 12 carbon atoms in the molecule, and an epoxy compound.

Abstract: A lubrication method including lubricating a sliding member which contains at least one selected from the group consisting of a liquid crystal polymer and polyetheretherketone by using a lubricating oil composition which contains an ester as a lubricating base oil.