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 mm.sup.2/s or more and 2.5 mm.sup.2/s or less.

Lubricant compositions comprising a base oil, one or more antioxidants selected from a group consisting of N-α-naphthyl-N-phenylamine antioxidants and diphenylamine antioxidants; and a sulfur-containing additive comprising up to seven carbon atoms exhibit outstanding oxidative stability and non-corrosion properties. The N-α-naphthyl-N-phenylamine antioxidants plus diphenylamine antioxidants in total may be present from about 0.2 wt % to about 0.8 wt %, based on the total weight of the lubricant composition. The sulfur provided by the sulfur-containing additive may be present from about 50 ppm to about 1000 ppm by weight, based on the total weight of the lubricant composition.

Provided is a grease composition which contains (A) a mixed base oil containing (A1) a low-viscosity base oil having a kinematic viscosity at 40° C. of 10 to 50 mm.sup.2/s and (A2) a high-viscosity base oil having a kinematic viscosity at 40° C. of 200 to 700 mm.sup.2/s, (B) a lithium-based thickener and (C) a polymer having a kinematic viscosity at 100° C. of 1,000 to 100,000 mm.sup.2/s, and has an apparent viscosity at −10° C., as measured according to JIS K2220:2013 and at a shear rate of 10 s.sup.−1, of 50 to 250 mPa.Math.s. The grease composition is excellent in pumpability and is also excellent in wear resistance under poor lubrication conditions.

A grease composition may contain a base oil (A) and a urea-based thickener (B). Particles containing the urea-based thickener (B) in the grease composition may satisfy requirement (I). The base oil (A) may be a mixed base oil containing a high-viscosity base oil (A1) having a kinematic viscosity at 40° C. of 250 mm.sup.2/s to 550 mm.sup.2/s, a low-viscosity base oil (A2) having a kinematic viscosity at 40° C. of 5.0 mm.sup.2/s to 110 mm.sup.2/s, and an ultra-high viscosity hydrocarbon-based synthetic oil (A3) having a number average molecular weight (Mn) of 2,500 to 4,500 and a kinematic viscosity at 40° C. of 25,000 mm.sup.2/s to 50,000 mm.sup.2/s. The base oil (A) may have a kinematic viscosity at 40° C. of 25 mm.sup.2/s to 105 mm.sup.2/s and a viscosity index of 120 or more. Both low-temperature characteristics and a lubricating life can be achieved.

Provided are: an ionic liquid including the fluorine-containing phosphate ester anions represented by formula (1); and a lubricating oil composition including said ionic liquid.

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(In the formula, Rf represents a C1-14 perfluoroalkyl group. R.sup.1 represents a C1-8 alkyl group.)

A lubricating oil composition may be capable of satisfactorily exhibiting sludge prevention properties and wear resistance evaluated by scoring resistance and seizure resistance over a long period of time. Such a lubricating oil composition may contain: a base oil (A); a hindered phenol-based antioxidant (B); one or more imide compounds (C) selected from the group consisting of a monoimide compound (C1) and a bisimide compound (C2); and an extreme pressure agent (D), in which the hindered phenol-based antioxidant (B) is 2,6-di-tert-butylphenol, the monoimide compound (C1) is one or more selected from the group consisting of an alkenyl succinic monoimide compound and an alkyl succinic monoimide compound, and the bisimide compound (C2) is one or more selected from the group consisting of an alkenyl succinic bisimide compound and an alkyl succinic bisimide compound.

The present disclosure relates to a synthetic vegetable oil and an environmental-friendly flame-retardant hydraulic oil composition including the same, and a preparation method thereof, and provides a method of preparing a glycerin-ester-based lubricating base oil through a catalyst-free and rinsing-free process, a glycerin-ester-based lubricating base oil that is a synthetic vegetable oil obtained by the method, and an environmental-friendly flame-retardant hydraulic oil composition that contains the glycerin-ester-based lubricating base oil and that is capable of reducing electricity consumption by 7 to 8% compared to mineral oil-based lubricating oils due to excellent flame retardancy (with self-extinguishing function) and lubricity.

The present invention relates to a lubricating composition containing: an oil of lubricating viscosity, a non-borated dispersant, a detergent, and an antiwear package comprising (a) a derivative of a hydroxycarboxylic acid, (b) an amine salt of a phosphoric acid ester, and (c) a phosphite having at least one hydrocarbyl group with 4 or more carbon atoms. The invention further provides for a method of lubricating a driveline device application by employing a lubricating composition containing the antiwear package.

The disclosed technology relates to an additive composition and lubricating grease composition containing a synergistic combination of ingredients for inhibiting rust, particularly rust on mechanical devices subject to contact with salt water.

The invention relates to a grease composition including a base oil and a thickener that provides hydrophilic metal oxide particles and one or more amides which contain one or more unsaturated C—C bonds and/or at least one OH group. The hydrophilic metal oxide particles have a BET specific surface area of at least 10 m2/g and at least 80% of the hydrophilic metal oxide particles have a particle size in the range of from 5 nm to 900 μm. The amount of the thickener is in the range of from 0.1-40% by weight, based on the total weight of the grease composition. The invention further relates to methods for manufacturing the grease composition, and the use of the grease composition for lubricating bearings, gears and couplings.