A grease composition for constant velocity joints can have excellent wear resistance, and may include a base oil (A) and a urea-based thickening agent (B) of formula (B1): R.sup.1—NHCONH—R.sup.3—NHCONH—R.sup.2 (B1), wherein R.sup.1 and R.sup.2 are independently a monovalent C6 to C24 hydrocarbon group, R.sup.1 and R.sup.2 optionally differing; and R.sup.3 is a divalent C6 to C18 aromatic hydrocarbon group, the monovalent hydrocarbon group containing an alicyclic hydrocarbon group and a hydrocarbon chain, and optionally containing an aromatic hydrocarbon group, wherein, in R.sup.1 and R.sup.2 of formula (B1), if the content of the alicyclic hydrocarbon group is X molar equivalent, the content of the hydrocarbon chain is Y molar equivalent, and the content of the aromatic hydrocarbon group is Z molar equivalent, (a) and (b) are satisfied: (a): a value of {(X+Y)/(X+Y+Z)}×100 is 90 or more; (b): an X/Y ratio is 10/90 to 75/25.

A non-volatile memory circuit in embodiments of the present invention may have one or more of the following features: (a) a logic source, and (b) a semi-conductive device being electrically coupled to the logic source, having a first terminal, a second terminal and a nano-grease with significantly reduced amount of carbon nanotube loading located between the first and second terminal, wherein the nano-grease exhibits non-volatile memory characteristics.

The present invention provides a mineral base oil having a kinetic viscosity at 100 C. of 7 mm.sup.2/s or more and less than 10 mm.sup.2/s, a viscosity index of 100 or more, and a temperature gradient |*| complex viscosity between two temperature points of 5 C. and 15 C. of 240 mPa.Math.s/ C. or less as measured with a rotary rheometer at an angular velocity of 6.3 rad/s. The use of the mineral base oil enables easy preparation of a lubricating oil composition and a grease composition having excellent oxidation stability while ensuring the freedom of selection of additives.

A grease composition includes a base oil, a thickener, and zirconium oxide particles. The base oil is a poly--olefin. The zirconium oxide particles have a median diameter D.sub.50 of 0.6 m to 4 m. A content of the zirconium oxide particles is 2% by mass to 15% by mass with respect to a total amount of the base oil and the thickener.

The present invention provides a grease composition for constant velocity joints, which includes a lubricating base oil, a thickener including a nitrogen-containing compound, a triglyceride, a diester, and a boron nitride, wherein a total content of the triglyceride and the diester is 1 to 5 mass % based on a total amount of the grease composition, and a mass ratio of a content of the triglyceride to a content of the diester (triglyceride/diester) is 0.3 to 1.5.

A lubricant composition according to the present invention contains a fatty acid metal salt, a metal dithiocarbamate, and an additive having an effect of increasing an acid value of the lubricant composition, whereby fretting resistance performances are further improved.

A grease of the invention contains a base oil and a thickener, where, when the volumetric-based arithmetic mean particle size of particles contained in the grease measured using laser diffraction/scattering method is A (unit: m), a formula A3 (1) is satisfied.

A grease of the invention contains a base oil and a thickener, where, when the volumetric-based arithmetic mean particle size of particles contained in the grease measured using laser diffraction/scattering method is A (unit: m), a formula A3 (1) is satisfied.

This disclosure relates to grease compositions having at least one base oil, and at least one thickener. The at least one thickener includes a combination of calcium sulfonate and a polyurea. The grease compositions have a service life or time at which 50 percent of the bearings fail (L50) of at least 100 hours at a temperature of 160 C., in accordance with DIN 51821 (FAG FE9). The calcium sulfonate includes from 60 weight percent to 95 weight percent, based on the total weight of the thickener, and the polyurea comprises from 5 weight percent to 40 weight percent, based on the total weight of the thickener. This disclosure also relates to a method of preparing the grease compositions. This disclosure further relates to a method for improving high temperature performance of a grease composition in a mechanical component lubricated with the grease composition.

This disclosure relates to grease compositions having at least one base oil, and at least one polyurea thickener. The at least one polyurea thickener is prepared by reacting an isocyanate-terminated prepolymer with at least one amine under reaction conditions sufficient to prepare the at least one polyurea thickener. The isocyanate-terminated prepolymer is prepared by reacting a polyisocyanate with a polyol, at an NCO/OH equivalent ratio of 1.05:1 to 10:1, under reaction conditions sufficient to prepare said isocyanate-terminated prepolymer. When the grease compositions are used under high temperature conditions, structural stability and resistance to breaking down in accordance with DIN 51821 (FAG FE9) is improved. This disclosure also relates to a method of preparing the grease compositions. This disclosure further relates to a method for improving high temperature performance of a grease composition in a mechanical component lubricated with the grease composition.