A viscosity index improver containing, in non-ester diluent oil, one or more hydrogenated, functionalized linear block copolymers having at least one block derived from monoalkenyl arene covalently linked to at least one block derived from diene in an amount that is greater than the critical overlap concentration (c.sub.h*), in mass %, for the linear block copolymers in the diluent oil; and an amount of ester base stock.

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 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.

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.

This disclosure relates to grease compositions having at least one base oil, at least one soap or non-soap thickener, and at least one elastomeric triblock copolymer of the general configuration A-B-A, in which A is a relatively hydrophobic polymer block and B is a relatively hydrophilic polymer block, and in which A forms less than 50% by weight of the total molecular weight of the elastomeric triblock copolymer. When the grease compositions are used under high shear conditions, structural stability and resistance to breaking down in accordance with ASTM D7342 is improved. When the grease compositions are used in low temperature conditions, low temperature starting and running torque in accordance with ASTM D1478 is improved.

This disclosure relates to grease compositions having at least one base oil, at least one soap or non-soap thickener, and at least one elastomeric triblock copolymer of the general configuration A-B-A, in which A is a relatively hydrophobic polymer block and B is a relatively hydrophilic polymer block, and in which A forms less than 50% by weight of the total molecular weight of the elastomeric triblock copolymer. When the grease compositions are used under high shear conditions, structural stability and resistance to breaking down in accordance with ASTM D7342 is improved. When the grease compositions are used in low temperature conditions, low temperature starting and running torque in accordance with ASTM D1478 is improved.

A grease composition includes base oil, a thickener, and an inorganic additive. The base oil is a poly--olefin having a base oil kinematic viscosity of 15 to 50 mm.sup.2/s at 40 C. The thickener is a diurea expressed by Structural Formula (1). The content of the thickener is 10 to 22 mass % with respect to the total amount of the base oil and the thickener. The inorganic additive is a mixture containing sepiolite and bentonite, and is organically modified. The content of the inorganic additive is 2 to 20 mass % with respect to the total amount of the base oil and the thickener.

R.sup.1NHCONHR.sup.2NHCONHR.sup.3 (1)

A grease composition includes base oil, a thickener, and an inorganic additive. The base oil is a poly--olefin having a base oil kinematic viscosity of 15 to 50 mm.sup.2/s at 40 C. The thickener is a diurea expressed by Structural Formula (1). The content of the thickener is 10 to 22 mass % with respect to the total amount of the base oil and the thickener. The inorganic additive is a mixture containing sepiolite and bentonite, and is organically modified. The content of the inorganic additive is 2 to 20 mass % with respect to the total amount of the base oil and the thickener.

R.sup.1NHCONHR.sup.2NHCONHR.sup.3 (1)

The invention discloses a lubricating grease with thixotropy and a preparation method thereof. The lubricating grease comprises a polyurea/high base number calcium sulfonate composite thickener, colloidally dispersed calcium carbonate solid particles in the form of calcite, a calcium borate or calcium borate composite, and a calcium soap of fatty acid having 12 to 24 carbon atoms. The above components are uniformly dispersed in an oil phase medium. The content of high base number calcium sulfonate in the lubricating grease is less than 22 wt %, and the lubricating grease has a worked cone penetration of 295 or less.