Abstract: The present invention provides a refrigerating machine oil containing an ester base oil obtained from pentaerythritol and mixed fatty acids of a fatty acid having 8 carbon atoms and a fatty acid having 9 carbon atoms, wherein a ratio of a weight average molecular weight Mw to a number average molecular weight Mn, Mw/Mn, of the ester base oil is 1.06 to 1.20, and used with a mildly flammable hydrofluorocarbon refrigerant.

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 5.8 or less, wherein the refrigerating machine oil is used with a refrigerant comprising 15% by mass or more of difluoromethane, 15% by mass or more of pentafluoroethane, 15% by mass or more of 2,3,3,3-tetrafluoropropene and 15% by mass or more of 1,1,1,2-tetrafluoroethane based on the total amount of the refrigerant.

Abstract: The present invention provides a refrigerating machine oil comprising: a base oil; 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 a hydrogen atom or a monovalent hydrocarbon group; and an epoxy compound.

Abstract: The present invention provides a working fluid composition for a refrigerating machine containing: a refrigerating machine oil containing, as a base oil, a mixed ester of (A) a complex ester synthesized from a polyhydric alcohol such as neopentyl glycol, a polybasic acid having 6 to 12 carbon atoms, a monohydric alcohol having 4 to 18 carbon atoms and the like, and (B) a polyol ester synthesized from a polyhydric alcohol such as neopentyl glycol and a monocarboxylic fatty acid having 4 to 18 carbon atoms, in a mass ratio of (A) the complex ester/(B) the polyol ester of 5/95 to 95/5; and a refrigerant such as carbon dioxide.

Abstract: The present invention provides a refrigerating machine oil comprising: a base oil comprising an ester of a polyhydric alcohol and a fatty acid comprising 20 to 100% by mol of a branched fatty acid having 4 to 9 carbon atoms; and 0.2 to 0.5% by mass of a phenol-based antioxidant based on a total amount of the refrigerating machine oil, and the refrigerating machine oil being used with trifluoroethylene refrigerant.

Abstract: A method of producing a regenerated hydrotreating catalyst, including a first step of preparing a hydrotreating catalyst that has been used for hydrotreatment of a petroleum fraction and has a metal element selected from Group 6 elements of the periodic table; a second step of performing regeneration treatment for part of the catalyst prepared in the first step, then performing X-ray absorption fine structure analysis for the catalyst after the regeneration treatment, and obtaining regeneration treatment conditions in which a ratio IS/IO of a peak intensity IS of a peak attributed to a bond between the metal element and a sulfur atom to a peak intensity IO of a peak attributed to a bond between the metal element and an oxygen atom is in the range of 0.1 to 0.3 in a radial distribution curve obtained from an extended X-ray absorption fine structure spectrum.

Abstract: A working fluid composition for a refrigerating machine comprises a refrigerant comprising monofluoroethane and a refrigerating machine oil comprising, as a base oil, at least one selected from a mineral oil having % CN in an n-d-M ring analysis of 10 to 60 and a pour point of ?15° C. or lower and a synthetic hydrocarbon oil having a pour point of ?15° C. or lower, and the refrigerating machine oil having a kinematic viscosity at 40° C. of 3 to 500 mm2/s.

Abstract: 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 mm2/s or more.

Abstract: The present invention provides a refrigerating machine oil comprising, as a base oil, a polymer having a structural unit represented by the following formula (1): wherein R1, R2 and R3, which may be the same as or different from each other, represent a hydrogen atom or a hydrocarbon group; and R4 represents a hydrocarbon group or an organic group containing an oxygen atom, and having a number average molecular weight Mn of 300 or more and 3000 or less and a ratio of a weight-average molecular weight Mw to a number average molecular weight Mn (Mw/Mn) of 1.10 or more and 2.00 or less, and the refrigerating machine oil being used with a refrigerant selected from the group consisting of 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, unsaturated hydrofluorocarbons, hydrocarbons and carbon dioxide.

Abstract: 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 mm2/s or more.

Abstract: 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 and (B) a polyol ester, wherein (A) is obtainable by synthesis from a specific polyhydric alcohol, a polybasic acid having 6 to 12 carbon atoms, and a monohydric alcohol having 4 to 18 carbon atoms or a monocarboxylic acid having 4 to 18 carbon atoms, wherein (B) is obtainable by synthesis from a specific polyhydric alcohol and a monocarboxylic acid having 4 to 18 carbon atoms, and wherein a mass ratio of (A)/(B) is 5/95 to 95/5; and difluoromethane used as a refrigerant, and the working fluid composition having a refrigerant dissolved viscosity of 5.5 mm2/s or more, at a temperature of 80° C. and an absolute pressure of 2.1 MPa.

Abstract: The present invention provides a refrigerating machine oil comprising a polyvinylether having a structural unit represented by the following formula (1): wherein R1, R2, and R3 may be the same or different from each other and each represent a hydrogen atom or a hydrocarbon group, R4 represents a divalent hydrocarbon group or an ethereal oxygen-containing divalent hydrocarbon group, R5 represents a hydrocarbon group, m represents an integer of 0 or more, and in the case where m is 2 or more, a plurality of R4 may be the same or different from each other, a number average molecular weight Mn is 500 or more and 2000 or less, a ratio of a weight average molecular weight Mw to a number average molecular weight Mn, Mw/Mn, is 1.10 or more and 1.25 or less, and the refrigerating machine oil is used with a mildly flammable hydrofluorocarbon refrigerant.

Abstract: Disclosed is a working fluid composition for a refrigerating machine, comprising a refrigerating machine oil comprising an ester of a polyhydric alcohol and a fatty acid, a carbodiimide compound, and a phosphorous compound, and at least one refrigerant selected from 1, 1, 1,2-tetrafluoroethane and 2,3,3,3-tetrafluoropropene, the fatty acid comprises at least one selected from fatty acids having 4 to 9 carbon atoms, and the carbodiimide compound and the phosphorus compound satisfy the conditions represented by the formula (1): 0.11 ? ( N C M C · W C ) ( N P M P · W P ) ? 4.

Abstract: The 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 5.8 or less, and the refrigerating machine oil being used with a 1-chloro-3,3,3-trifluoropropene refrigerant.

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

Abstract: The present invention provides a working fluid composition for a refrigerating machine, comprising a refrigerating machine oil that comprises an ester of a polyhydric alcohol and a fatty acid, an epoxy compound, and a phosphorus compound, and a fluoropropene refrigerant, wherein the polyhydric alcohol constituting the ester comprises pentaerythritol and dipentaerythritol, the fatty acid constituting the ester comprises at least one selected from fatty acids having 4 to 9 carbon atoms, and the epoxy compound and the phosphorus compound satisfy a condition represented by the following formula (1). [ Formula ? ? 1 ] ? 0.10 ? ( N E M E · W E ) ( N P M P · W P ) ? 1.

Abstract: The present invention provides a refrigerating machine oil comprising at least one oxygen-containing oil having a carbon/oxygen molar ratio of 2.5 or more and 5.8 or less as a base oil, and the refrigerating machine oil being used with a trifluoroethylene refrigerant.

Abstract: Disclosed is a working fluid composition for a refrigerating machine, comprising a refrigerating machine oil comprising an ester of a polyhydric alcohol and a fatty acid, a carbodiimide compound, and a phosphorous compound, and at least one refrigerant selected from 1, 1, 1,2-tetrafluoroethane and 2,3,3,3-tetrafluoropropene, the fatty acid comprises at least one selected from fatty acids having 4 to 9 carbon atoms, and the carbodiimide compound and the phosphorus compound satisfy the conditions represented by the formula (1): 0.11 ? ( N C M C · W C ) ( N P M P · W P ) ? 4.

Abstract: The present invention provides a working fluid composition for a refrigerating machine containing: a refrigerating machine oil containing, as a base oil, a mixed ester of (A) a complex ester synthesized from a polyhydric alcohol such as neopentyl glycol, a polybasic acid having 6 to 12 carbon atoms, a monohydric alcohol having 4 to 18 carbon atoms and the like, and (B) a polyol ester synthesized from a polyhydric alcohol such as neopentyl glycol and a monocarboxylic fatty acid having 4 to 18 carbon atoms, in a mass ratio of (A) the complex ester/(B) the polyol ester of 5/95 to 95/5; and a refrigerant such as carbon dioxide.

Abstract: 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 mm2/s or more.