Provided is a lubricating oil composition for use in turbomachinery, compressors, hydraulic equipments, or machine tools, which contains a mineral oil (A) and a synthetic oil (B) containing a polyalkylene glycol (B1) and a polyol ester (B2), in which the content of the mineral oil (A) is 5 to 95% by mass based on the total amount of the lubricating oil composition, and which is used in turbomachinery, compressors, hydraulic equipments, or machine tools. The lubricating oil composition is excellent in oxidation stability, has a strong effect of preventing sludge precipitation and has excellent water separability even in use for a long period of time in high-temperature environments.

A lubricating oil composition excellent in the wear resistance and a refrigerator oil composition excellent in the oxidation stability using the lubricating oil composition are provided by a lubricating oil composition containing a base oil (A) and a phosphine derivative (B) having one or more oxygen atom in a molecule.

A lubricating oil composition contains a base oil and a rust inhibitor, in which the base oil has a gas chromatogram measured by gas chromatography satisfying the particular condition (), and the rust inhibitor is at least one selected from a first rust inhibitor, a second rust inhibitor, a third rust inhibitor, and a fourth rust inhibitor, and satisfies the particular condition ().

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.

In some embodiments, ethylene-propylene random copolymers as viscosity modifiers were synthesized with pyridyldiamido catalyst systems and a chain transfer agent. In some embodiments, the present disclosure provides for ethylene-propylene random copolymers having an ethylene content between about 45 wt % and about 55 wt %. In some embodiments, the ethylene-propylene random copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

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):

##STR00001##

wherein R.sup.1 and R.sup.2 each independently represent a monovalent hydrocarbon group, R.sup.3 represents a divalent hydrocarbon group, and R.sup.4 represents hydrogen atom or a monovalent hydrocarbon group, and the refrigerating machine oil having a kinematic viscosity at 40 C. of 10 mm.sup.2/s or less.

The lubricating oil composition of the present invention contains a base oil, a 2,6-di-tert-butylphenol (A), and at least one compound (B) selected from a benzotriazole compound and a sorbitan compound.

A surface protection composition which is hard to deform or flow even placed under environments of a large temperature change with an external physical load such as pressure, and which stably protects a metal surface. A terminal fitted electric wire coated with the composition. The surface protection composition contains a high-consistency material (A) containing a lubricant base oil and an amide compound, and a phosphorus composition (B). The phosphorus composition (B) contains a composition (b1) containing one or more compounds represented by the general formulae (1) and (2) and one or more metals and/or one or more amines. The phosphorus composition (B) also contains one or more compounds (b2) represented by the general formula (3).

A refrigerating machine oil having a kinematic viscosity at 100 C. of 0.5 mm.sup.2/s or more and 2.5 mm.sup.2/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.

The present invention provides a refrigerating machine oil comprising: a base oil; a compound represented by the following formula (1): ##STR00001##
wherein R.sup.1 and R.sup.2 each independently represent a monovalent hydrocarbon group, R.sup.3 represents a divalent hydrocarbon group and R.sup.4 represents a hydrogen atom or a monovalent hydrocarbon group; and an epoxy compound.