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: 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: 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: 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: 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: The present invention, in one aspect, provides a refrigerating machine oil including a lubricating base oil and a compound represented by the following formula (A): wherein R1 and R2 each independently represent a monovalent hydrocarbon group, and R3 and R4 each independently represent a hydrogen atom or an alkyl group, the refrigerating machine oil being used with a refrigerant including an unsaturated hydrofluorocarbon.

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: The present invention provides a refrigerating machine oil comprising: a lubricating base oil; and 40 mass % or less of a polymer, based on a total amount of the refrigerating machine oil, the polymer having a structural unit represented by the following formula (I) and a weight average molecular weight of from 500 to 100000. [In formula (I), Ra, Rb and Rc each independently represents a hydrogen atom or a hydrocarbon group, and Rd represents an oxygen-containing organic group or a C1-18 hydrocarbon group.

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: 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 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: 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, as a base oil, at least one oxygen-containing oil having a carbon/oxygen molar ratio of 2.5 or more and 7.5 or less, and the refrigerating machine oil being used with a 1-chloro-2,3,3,3-tetrafluoropropene refrigerant.

Abstract: The present invention provides a working fluid composition for a refrigerating machine containing: a refrigerating machine oil containing: a first ester that is a polyol ester of dipentaerythritol and at least one fatty acid selected from fatty acids having 4 to 10 carbon atoms, and has a kinematic viscosity at 100° C. of 7.0 mm2/s or more; and a second ester that is a complex ester of a polyhydric alcohol containing at least one selected from neopentyl glycol, trimethylolpropane and pentaerythritol, a polybasic acid having 6 to 12 carbon atoms, and a monohydric alcohol having 4 to 18 carbon atoms or a fatty acid having 4 to 18 carbon atoms; and a refrigerant containing difluoromethane.

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 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 and 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.

Abstract: The present invention provides a refrigerating machine oil comprising: a base oil containing an ester of dipentaerythritol with 2-methylbutanoic acid and n-pentanoic acid; and at least one epoxy compound selected from the group consisting of a glycidyl ester compound and a glycidyl ether compound, the refrigerating machine oil being used with a difluoromethane refrigerant.