Problems addressed by the present invention are to provide a lubricant composition that is capable of being used as an alternative to chemical conversion treatment by means of phosphate, to provide a lubricant composition having practical stable lubricative performance without the need for additional unwanted operations, and to provide a method for using this to form a lubrication coating, and a metal workpiece at which a lubrication coating is formed on a surface thereof. Provided as a means for solving such problems is a lubricant composition for causing formation of a hemimorphite-containing lubrication coating that contains a silicate compound (e.g., colloidal silica) and water-soluble zinc in solution.

A constant velocity joint having a boot constructed from a thermoplastic polyether ester as the boot material. The boot includes a lubricating grease composition for lubricating the constant velocity joint, the lubricating grease composition comprising calcium lignin sulfonate.

Provided is a rust-preventive composition showing excellent rust-preventive performance for plate joining parts such as doors of automotive bodies, the composition having sufficient corrosion resistance and being capable of preventing dripping from automotive bodies. A rust-preventive composition including: a rust-preventive additive; a wax having a melting point within the range of 60° C. to 130° C. selected from microcrystalline waxes and polyethylene-based or polypropylene-based synthetic waxes; bentonite; a hydrogenated oil; and two or more kinds of diluents having different viscosities; the rust-preventive additive being contained in an amount within the range of 12% by mass to 39% by mass with respect to the total composition, the bentonite being contained in an amount within the range of 2% by mass to 6% by mass with respect to the total composition, the wax being contained in an amount within the range of 3% by mass to 13% by mass with respect to the total composition.

Provided is a rust-preventive composition showing excellent rust-preventive performance for plate joining parts such as doors of automotive bodies, the composition having sufficient corrosion resistance and being capable of preventing dripping from automotive bodies. A rust-preventive composition including: a rust-preventive additive; a wax having a melting point within the range of 60° C. to 130° C. selected from microcrystalline waxes and polyethylene-based or polypropylene-based synthetic waxes; bentonite; a hydrogenated oil; and two or more kinds of diluents having different viscosities; the rust-preventive additive being contained in an amount within the range of 12% by mass to 39% by mass with respect to the total composition, the bentonite being contained in an amount within the range of 2% by mass to 6% by mass with respect to the total composition, the wax being contained in an amount within the range of 3% by mass to 13% by mass with respect to the total composition.

A lubricating oil composition may include a base oil (A), succinimide (B) which has not been modified with boron, succinimide (C) modified with boron, a metallic detergent (D), and an antioxidant (E), wherein the ratio of the content of boron atoms derived from ingredient (C) to the content of nitrogen atoms derived from ingredients (B) and (C), B/N, is 0.30 or less by mass, the lubricating oil composition satisfying requirement (I) and/or requirement (II). Requirement (I): Ingredient (D) includes a metallic detergent (D1) having a base value less than 100 mgKOH/g. Requirement (II): Ingredient (E) includes an amine-based antioxidant (E1), the content of ingredient (E1) being 1.00 mass % or less.

A lubricating oil composition may include a base oil (A), succinimide (B) which has not been modified with boron, succinimide (C) modified with boron, a metallic detergent (D), and an antioxidant (E), wherein the ratio of the content of boron atoms derived from ingredient (C) to the content of nitrogen atoms derived from ingredients (B) and (C), B/N, is 0.30 or less by mass, the lubricating oil composition satisfying requirement (I) and/or requirement (II). Requirement (I): Ingredient (D) includes a metallic detergent (D1) having a base value less than 100 mgKOH/g. Requirement (II): Ingredient (E) includes an amine-based antioxidant (E1), the content of ingredient (E1) being 1.00 mass % or less.

A lubricating oil composition containing a base oil (A), a comb-shaped polymer (B), and an olefin-based copolymer (C), wherein a content of the component (B) is more than 0.80 mass % based on the total amount of the lubricating oil composition, a weight average molecular weight of the component (C) is 500,000 or more, and the lubricating oil composition has a viscosity index of 200 or more and a kinematic viscosity at 100° C. of 9.3 to 11.0 mm.sup.2/s.

A lubricating oil composition containing a base oil (A), a comb-shaped polymer (B), and an olefin-based copolymer (C), wherein a content of the component (B) is more than 0.80 mass % based on the total amount of the lubricating oil composition, a weight average molecular weight of the component (C) is 500,000 or more, and the lubricating oil composition has a viscosity index of 200 or more and a kinematic viscosity at 100° C. of 9.3 to 11.0 mm.sup.2/s.

A grease composition which contains a base oil (A), a urea-based thickener (B), a sarcosine derivative (C), and a fatty acid zinc salt (D), wherein particles containing the urea-based thickener (B) in the grease composition satisfies Requirement (I). The base oil (A) is a blended base oil containing a high viscosity hydrocarbon-based synthetic oil having a specific kinematic viscosity (A1). A low viscosity hydrocarbon-based synthetic oil having a specific kinematic viscosity (A2). An ultra-high viscosity hydrocarbon-based synthetic oil has a number average molecular weight (Mn) of 2,500 to 4,500 and a specific kinematic viscosity (A3). A 40° C. kinematic viscosity of the base oil (A) is 500 mm.sup.2/s to 1,500 mm.sup.2/s. A viscosity index of the base oil (A) is 140 or more. A content of the fatty acid zinc salt (D) is 10 mass % to 20 mass % based on a total amount of the grease composition.

A grease composition which contains a base oil (A), a urea-based thickener (B), a sarcosine derivative (C), and a fatty acid zinc salt (D), wherein particles containing the urea-based thickener (B) in the grease composition satisfies Requirement (I). The base oil (A) is a blended base oil containing a high viscosity hydrocarbon-based synthetic oil having a specific kinematic viscosity (A1). A low viscosity hydrocarbon-based synthetic oil having a specific kinematic viscosity (A2). An ultra-high viscosity hydrocarbon-based synthetic oil has a number average molecular weight (Mn) of 2,500 to 4,500 and a specific kinematic viscosity (A3). A 40° C. kinematic viscosity of the base oil (A) is 500 mm.sup.2/s to 1,500 mm.sup.2/s. A viscosity index of the base oil (A) is 140 or more. A content of the fatty acid zinc salt (D) is 10 mass % to 20 mass % based on a total amount of the grease composition.