The invention provides a grease composition suitable for being packed in roll bearings to be lubricated at elevated temperatures and a bearing in which the above-mentioned grease composition is packed. In the grease composition containing a base oil, a urea-containing thickener and an additive, the additive includes an overbased metal sulfonate and the amount of the overbased metal sulfonate is 0.05 to 1.00 mass % with respect to the total amount of the grease composition. The bearing has the above-mentioned grease composition sealed therein.

A lithium-based thickener is contained in an amount of 6 to 14 wt % based on a total weight of a grease composition. The amount of the lithium-based thickener contained in the grease composition can be reduced by about half compared to a conventional thickener, thus effectively increasing viscosity of base oil and reducing fluidity.

A grease composition comprises a thickener, a base oil, and a friction modifier. The friction modifier comprises: at least one selected from the group consisting of fatty acids, fatty acid metal salts, phosphate esters, thiophosphate esters, and zinc dithiophosphates; and a polyhydric alcohol ester.

A grease composition comprises a thickener, a base oil, and a friction modifier. The friction modifier comprises: at least one selected from the group consisting of fatty acids, fatty acid metal salts, phosphate esters, thiophosphate esters, and zinc dithiophosphates; and a polyhydric alcohol ester.

The invention provides a lubricating grease composition comprising an oil of lubricating viscosity, a metallic soap thickener and a boron-containing compound, wherein the boron containing compound comprises a borate ester comprising at least one alkyl group having a branch at the position or higher. The invention further relates to a method of lubricating a mechanical device with the lubricant composition.

The present disclosure is related to provide a lubricating grease composition having a high static friction coefficient while maintaining excellent low-temperature torque characteristics, high-temperature shear stability, and high-temperature oil separation characteristics.

A lubricating grease composition of the present disclosure contains a base oil, a thickener, and a solid lubricant, wherein the solid lubricant is calcium carbonate, the amount of the calcium carbonate blended is 1 to 60% by weight based on the total weight of the lubricating grease composition, the calcium carbonate has an average particle diameter of 0.1 to 30 m, the base oil has a kinematic viscosity of 18 to 300 mm.sup.2/s at 40 C., and the lubricating grease composition has a worked penetration of 240 to 320.

Disclosed in certain embodiments is a lubricating grease composition comprising an antioxidant polymer (e.g., oligomer) composition comprising repeat units of diphenylamine monomers of formula I

##STR00001##

wherein
R is H, C.sub.1-C.sub.18 alkyl, C.sub.2-C.sub.18 alkenyl, C.sub.2-C.sub.18 alkynyl, C(O)C.sub.1-C.sub.18 alkyl, C(O)aryl and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently H or a linear or branched C.sub.1-C.sub.18 alkyl, C.sub.1-C.sub.18 alkoxy, C.sub.1-C.sub.18 alkylamino, C.sub.1-C.sub.18 dialkylamino, C.sub.1-C.sub.18 alkylthio, C.sub.2-C.sub.18 alkenyl, C.sub.2-C.sub.18 alkynyl or C.sub.7-C.sub.21 aralkyl and
wherein
the number average molecular weight (Mn) of the polymer composition is from about 350 g/mol to about 5000 g/mol.

The object of the present invention is to provide a foreign substance removing lubricant composition having high foreign substance removing effects and being capable of improving the lubricating properties as compared to conventional lubricant compositions, a foreign substance removing lubricant composition applied member, and a method for using the foreign substance removing lubricant composition. The foreign substance removing lubricant composition of the present invention comprises a perfluoroalkyl group containing compound (S) having a perfluoroalkyl group or a fluoropolyether containing compound. As a result, foreign substance removing effects can be enhanced, and the lubricating properties can be improved as compared to the conventional lubricant compositions.

Provided is a lubricant for a gas insulated switchgear, with which properties of a base oil such as heat resistance, evaporation loss, fluidity under a low temperature, and chemical stability (oxidation resistance and HF resistance) are balanced at a level higher than the conventional level, and long service life and high reliability of the gas insulated switchgear are achieved. A lubricant for a gas insulated switchgear according to the present invention, contains: a base oil containing a polyalphaolefin having a kinematic viscosity at 40 C. of 50 mm.sup.2/s or more; and a thickener containing bisamides.

Provided herein are grease compositions comprising at least one estolide compound of formula: ##STR00001##
in which n is an integer equal to or greater than 0; m is an integer equal to or greater than 2; R.sub.1, independently for each occurrence, is selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; R.sub.2 is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; and R.sub.3 and R.sub.4, independently for each occurrence, are selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched. Also provided are methods of making estolide-based grease products.