An overbased calcium sulfonate grease composition comprising a reduced amount of overbased calcium sulfonate, calcium hydroxyapatite, base oil, one or more converting agents, and one or more complexing acids if a complex grease is desired. The calcium sulfonate grease composition improves thickener yield and expected high temperature utility as demonstrated by dropping point. A method of making the composition comprising the steps of mixing the calcium sulfonate and base oil, adding the calcium carbonate either before or after conversion, adding one or more converting agents, and adding one or more complexing acids. All or a portion of one or more of the complexing acids may be added with or prior to the one or more converting agents.

A grease composition containing a urea compound as a thickener, a base oil, an alkaline earth metal salicylate and/or an alkaline earth metal phenate as a first additive constituent, a metal soap, being a stearic acid metal salt, as a second additive constituent, and a calcium sulphonate and/or a zinc naphthenate as a third additive constituent.

A grease composition containing a urea compound as a thickener, a base oil, an alkaline earth metal salicylate and/or an alkaline earth metal phenate as a first additive constituent, a metal soap, being a stearic acid metal salt, as a second additive constituent, and a calcium sulphonate and/or a zinc naphthenate as a third additive constituent.

The invention provides a lubricant composition for an eccentrically oscillating speed reducer of planetary gear type, which is capable of extending the life of the speed reducer under high temperatures and keeping low input torque at low temperatures, and includes (a) a base oil containing a synthetic oil, (b) a hydrocarbon wax, and (c) at least one calcium salt selected from the group consisting of a calcium salt of petroleum sulfonic acid, a calcium salt of alkyl aromatic sulfonic acid, a calcium salt of oxidized wax, an overbasic calcium salt of petroleum sulfonic acid, an overbasic calcium salt of alkyl aromatic sulfonic acid, and an overbasic calcium salt of oxidized wax.

Provided is a grease composition which is excellent in fire extinguishing performance without water and can suppress fuming, malodor, and liquefaction on burning and a method for producing the grease composition. A grease composition contains a base oil (A), a thickener (B), and a fire retardant (C), wherein the base oil (A) contains a base oil (A1) having a 40° C. kinematic viscosity of 300 mm.sup.2/s or more, a sulfur content of 20 ppm by mass or less, and an initial boiling point of 400° C. or higher, the fire retardant (C) is at least one of aluminum hydroxide (C1) and 1,3,5-triazine-1,3,5 (2H, 4H, 6H)-tris(ethanol) (C2), and a content of the fire retardant (C) is 1.0 to 12.0 mass % based on a total amount of the grease composition.

Provided is a mixed grease containing a grease (A) prepared from a base oil (a1) and a thickening agent (a2) that is a lithium soap consisting of a lithium salt of a monovalent fatty acid, and a grease (B) prepared from a base oil (b1) and a thickening agent (b2) that is a lithium complex soap consisting of a lithium salt of a monovalent fatty acid and a lithium salt of a divalent fatty acid. The mixed grease has good wear resistance and load bearing properties and has excellent grease leakage preventing properties.

Provided is a mixed grease containing a grease (A) prepared from a base oil (a1) and a thickening agent (a2) that is a lithium soap consisting of a lithium salt of a monovalent fatty acid, and a grease (B) prepared from a base oil (b1) and a thickening agent (b2) that is a lithium complex soap consisting of a lithium salt of a monovalent fatty acid and a lithium salt of a divalent fatty acid. The mixed grease has good wear resistance and load bearing properties and has excellent grease leakage preventing properties.

A grease composition containing a base oil (A), a urea-based thickener (B), an antioxidant (C), and a rust inhibitor (D), wherein in a particle size distribution curve obtained by measuring the particle size of particles containing the urea-based thickener (B) in the grease composition on a volume basis with light scattering, a peak indicating the maximum frequency satisfies the following Requirements (I) and (II): (I) a particle size indicating the maximum frequency of the peak is 1.0 μm or less; and (II) a half width of the peak is 1.0 μm or less.

The invention provides a grease composition for lubricating resins which contains a base oil, a diurea compound represented by formula (I) as a thickener: R.sup.1NHCONHR.sup.2NHCONHR.sup.3 (I) (wherein R.sup.2 represents a bivalent aromatic hydrocarbon group having 6 to 15 carbon atoms, and R.sup.1 and R.sup.3 each independently represent a straight-chain or branched alkyl group having 8 to 22 carbon atoms), and a chained hydrocarbon polymer having a weight-average molecular weight of 20,000 to 300,000.

The invention provides a grease composition for lubricating resins which contains a base oil, a diurea compound represented by formula (I) as a thickener: R.sup.1NHCONHR.sup.2NHCONHR.sup.3 (I) (wherein R.sup.2 represents a bivalent aromatic hydrocarbon group having 6 to 15 carbon atoms, and R.sup.1 and R.sup.3 each independently represent a straight-chain or branched alkyl group having 8 to 22 carbon atoms), and a chained hydrocarbon polymer having a weight-average molecular weight of 20,000 to 300,000.