Abstract: The lubricating oil composition of the invention comprises a lubricant base oil, a 3,4,5-trihydroxybenzoic acid ester at 5-5000 ppm by mass, and a phosphorus compound at 0.001-10.0% by mass, based on the total mass of the lubricating oil composition. The lubricating oil composition of the invention significantly lowers wear and exhibits a stable low frictional coefficient, while having a high rust-preventing effect for iron-based sliding sections. The lubricating oil composition of the invention is therefore suitable for prolonged use, and exhibits a notable effect for energy savings as well due to its stable low frictional coefficient property.

Abstract: The working fluid composition for a refrigerating machine of the present invention comprises: a refrigerating machine oil comprising a mineral oil and an alkylbenzene in a mass ratio, the mineral oil/the alkylbenzene, of 85/15 to 15/85, wherein the mineral oil has a % CN by n-d-M ring analysis of 20 to 60, a pour point of ?15° C. or less and a kinematic viscosity at 40° C. of 1.5 to 15 mm2/s; and a hydrocarbon refrigerant having 2 to 4 carbon atoms, wherein the refrigerating machine oil having a kinematic viscosity at 40° C. of 2 to 12 mm2/s and a flash point of 120° C. or more.

Abstract: A working fluid composition for a refrigerating machine comprising: a refrigerating machine oil containing at least one lubricating base oil selected from a mineral oil and a synthetic oil, and at least one phosphorus compound selected from a mono(alkylphenyl) diphenyl phosphate having a C3-C5 alkyl group and a di(alkylphenyl) phenyl phosphate having two C3-C5 alkyl groups, wherein a content of the phosphorus compound is 0.01 to 5% by mass based on a total amount of the refrigerating machine oil; and a hydrocarbon refrigerant having 2 to 4 carbon atoms.

Abstract: The working fluid composition for a refrigerating machine of the present invention comprises: a refrigerating machine oil comprising a mineral oil and an alkylbenzene in a mass ratio, the mineral oil/the alkylbenzene, of 85/15 to 15/85, wherein the mineral oil has a % CN by n-d-M ring analysis of 20 to 60, a pour point of ?15° C. or less and a kinematic viscosity at 40° C. of 1.5 to 15 mm2/s; and a hydrocarbon refrigerant having 2 to 4 carbon atoms, wherein the refrigerating machine oil having a kinematic viscosity at 40° C. of 2 to 12 mm2/s and a flash point of 120° C. or more.

Abstract: The lubricating oil composition of the invention comprises a lubricant base oil, a 3,4,5-trihydroxybenzoic acid ester at 5-5000 ppm by mass, and a phosphorus compound at 0.001-10.0% by mass, based on the total mass of the lubricating oil composition. The lubricating oil composition of the invention significantly lowers wear and exhibits a stable low frictional coefficient, while having a high rust-preventing effect for iron-based sliding sections. The lubricating oil composition of the invention is therefore suitable for prolonged use, and exhibits a notable effect for energy savings as well due to its stable low frictional coefficient property.