A continuous process for producing a polyurea concentrate or powder. The process includes combing at least one amine and an isocayante in the presence of a liquid diluent or a base oil in a rotor stator mixer. The concentrate comprises a polyurea in a base oil wherein the concentration of from about 20 weight percent to about 50, or 40 or 35 or 30 weight percent of polyurea based on total weight of grease thickener. The powder has particle size of 2 to 400 microns. This concentrate or powder can then be formulated by grease manufacturers to the desired final properties without the need for handling of the isocyanate and amine raw materials

A grease composition contains a mixture of a lubricating base oil, an ester-terminated polyamide and at least one polyolefin. The ester-terminated polyamide has the formula:
R1-O—CO—R2-CO—[NH—R3-NH—CO—R2-CO]n-O—R1.
R1 contains 4-22 carbon atoms, R2 contains 4-42 carbon atoms, R3 contains 2-9 carbon atoms and n is an integer in the range of 1-20. The grease composition can be used for lubricating a mechanical component having a metal surface and/or for protecting a mechanical component having a metal surface against corrosion, wear and/or fretting.

A grease composition contains a mixture of a lubricating base oil, an ester-terminated polyamide and at least one polyolefin. The ester-terminated polyamide has the formula:
R1-O—CO—R2-CO—[NH—R3-NH—CO—R2-CO]n-O—R1.
R1 contains 4-22 carbon atoms, R2 contains 4-42 carbon atoms, R3 contains 2-9 carbon atoms and n is an integer in the range of 1-20. The grease composition can be used for lubricating a mechanical component having a metal surface and/or for protecting a mechanical component having a metal surface against corrosion, wear and/or fretting.

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 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.

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.

The present disclosure provides a grease composition with improved water resistance and mechanical stability at high-temperatures, including: at least one base oil; a water insoluble thickener; and a low molecular weight thixotropic polyamide composition having molecular weight distribution characteristics meeting the requirement described by the relationship: $\frac{\left(A+D\right)}{\left(B+C\right)}0.05$
where A=the % mass of the polyamide composition with a molecular weight greater than 1700 AMU; B=the % mass of the polyamide composition with a molecular weight between 1100 AMU and 1300 AMU; C=the % mass of the polyamide composition with a molecular weight between 700 AMU and 1000 AMU; and D=the % mass of the polyamide composition with a molecular weight of 600 AMU or lower (determined by GPC). The grease composition of the present disclosure provides a less than 50 penetration point change as determined by ASTM-D7342, a less than 10 mg weight loss as determined by ASTM-D4170, or both.

The present disclosure provides a grease composition with improved water resistance and mechanical stability at high-temperatures, including: at least one base oil; a water insoluble thickener; and a low molecular weight thixotropic polyamide composition having molecular weight distribution characteristics meeting the requirement described by the relationship: $\frac{\left(A+D\right)}{\left(B+C\right)}0.05$
where A=the % mass of the polyamide composition with a molecular weight greater than 1700 AMU; B=the % mass of the polyamide composition with a molecular weight between 1100 AMU and 1300 AMU; C=the % mass of the polyamide composition with a molecular weight between 700 AMU and 1000 AMU; and D=the % mass of the polyamide composition with a molecular weight of 600 AMU or lower (determined by GPC). The grease composition of the present disclosure provides a less than 50 penetration point change as determined by ASTM-D7342, a less than 10 mg weight loss as determined by ASTM-D4170, or both.

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.