Abstract: Provided are: a lubricating oil composition for transmissions having a long fatigue life and a low viscosity, which contains a base oil and an olefin copolymer and in which the mass-average molecular weight of the olefin copolymer is 5,000 or more and 30,000 or less, the hydrodynamic radius of the olefin copolymer is 1.00 nm or more and 5.00 nm or less, and the content of the olefin copolymer based on the total amount of the composition is 1.0% by mass or more and 8.0% by mass or less; and a production method for the composition, a lubricating method using a lubricating oil composition for transmissions, and a transmission.

Abstract: A lubricating oil composition may include a base oil (A), an olefin copolymer (B), and a poly(alkyl(meth)acrylate) (C), in which a weight average molecular weight of the olefin copolymer (B) is 10,000 to 80,000, a content of the olefin copolymer (B) is 0.01% to 0.23% by mass based on the total amount of the lubricating oil composition, and a content of the poly(alkyl(meth)acrylate) (C) is 0.02% to 0.40% by mass based on the total amount of the lubricating oil composition.

Abstract: A lubricating oil composition may include a base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D) and a metal salt (E) including a metal sulfonate, a metal salicylate, and/or a metal phenate, in which a content of the acidic phosphorus compound (C) in terms of phosphorus atoms is 10 to 180 ppm by mass based on the total amount of the lubricating oil composition, a content of the sulfur compound (D) in terms of sulfur atoms is 10 to 1000 ppm by mass based on the total amount of the lubricating oil composition, and a content of the metal salt (E) in terms of metal atoms is 5 to 180 ppm by mass based on the total amount of the lubricating oil composition.

Abstract: Provided are: a lubricating oil composition for transmissions having a long fatigue life and a low viscosity, which contains a base oil and an olefin copolymer and in which the mass-average molecular weight of the olefin copolymer is 5,000 or more and 30,000 or less, the hydrodynamic radius of the olefin copolymer is 1.00 nm or more and 5.00 nm or less, and the content of the olefin copolymer based on the total amount of the composition is 1.0% by mass or more and 8.0% by mass or less; and a production method for the composition, a lubricating method using a lubricating oil composition for transmissions, and a transmission.

Abstract: A lubricating oil composition may include a base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D) and a metal salt (E) including a metal sulfonate, a metal salicylate, and/or a metal phenate, in which a content of the acidic phosphorus compound (C) in terms of phosphorus atoms is 10 to 180 ppm by mass based on the total amount of the lubricating oil composition, a content of the sulfur compound (D) in terms of sulfur atoms is 10 to 1000 ppm by mass based on the total amount of the lubricating oil composition, and a content of the metal salt (E) in terms of metal atoms is 5 to 180 ppm by mass based on the total amount of the lubricating oil composition.

Abstract: A lubricating oil composition may include a base oil (A), an olefin copolymer (B), and a poly(alkyl(meth)acrylate) (C), in which a weight average molecular weight of the olefin copolymer (B) is 10,000 to 80,000, a content of the olefin copolymer (B) is 0.01% to 0.23% by mass based on the total amount of the lubricating oil composition, and a content of the poly(alkyl(meth)acrylate) (C) is 0.02% to 0.40% by mass based on the total amount of the lubricating oil composition.

Abstract: A lubricating oil base oil may include a solid surface distance of 1.0 nm or more at a surface pressure of 12.4 MPa and a normalized peak intensity ratio of more than 0.2 to 1.0 measured using a resonance shear measurement system and a lubricating oil composition may include the lubricating oil base oil.

Abstract: Provided is a lubricating oil composition for engine equipped with a forced-induction mechanism capable of lowering the frequency of occurrence of LSPI, while using a calcium-based detergent. The lubricating oil composition for engine equipped with a forced-induction mechanism contains a base oil (A), a metal-containing surfactant (B) containing at least a calcium-containing surfactant (b1), and at least one basic compound (C) selected from a metal carbonate, a metal hydroxide, and an amine-based compound, wherein the content of sulfur contained in the metal-containing surfactant (B) is 0.2 mass % or more on the basis of the whole amount of the metal-containing surfactant (B); the content of a calcium atom is 0.08 to 0.20 mass % on the basis of the whole amount of the composition; and a mass ratio of the content of the basic compound (C) and the content of a calcium atom derived from the calcium-containing surfactant (b1) [(content of (C))/(calcium content derived from (b1))] is 2.0 or more.

Abstract: Provided is a lubricating oil composition having excellent detergency and LSPI preventing performance, and specifically a lubricating oil composition including a base oil, a calcium detergent, and a magnesium detergent and/or a sodium detergent, wherein the content of the calcium detergent as converted into a calcium atom and a mass ratio of a magnesium atom (Mg) contained in the magnesium detergent and/or a sodium atom (Na) contained in the sodium detergent to a calcium atom (Ca) [(Mg and/or Na)/Ca] fall within the specific ranges.

Abstract: The lubricating oil composition of the present invention contains, together with a base oil, a viscosity index improver (A) including a comb-shaped polymer (A1), a detergent dispersant (B) including an alkali metal borate (B1) and an organometallic compound (B2) containing a metal atom selected from an alkali metal atom and an alkaline earth metal atom, and a friction modifier (C) including a molybdenum-containing friction modifier, with the total content of an alkali metal atom and an alkaline earth metal atom being 2,000 mass ppm or less. The lubricating oil composition of the present invention has excellent detergency, fuel saving properties, and LSPI-preventing properties.

Abstract: Provided is a lubricating oil composition having excellent detergency and LSPI preventing performance, and specifically a lubricating oil composition including a base oil, a calcium detergent, and a magnesium detergent and/or a sodium detergent, wherein the content of the calcium detergent as converted into a calcium atom and a mass ratio of a magnesium atom (Mg) contained in the magnesium detergent and/or a sodium atom (Na) contained in the sodium detergent to a calcium atom (Ca) [(Mg and/or Na)/Ca] fall within the specific ranges.

Abstract: Provided is a lubricating oil composition for engine equipped with a forced-induction mechanism capable of lowering the frequency of occurrence of LSPI, while using a calcium-based detergent. The lubricating oil composition for engine equipped with a forced-induction mechanism contains a base oil (A), a metal-containing surfactant (B) containing at least a calcium-containing surfactant (b1), and at least one basic compound (C) selected from a metal carbonate, a metal hydroxide, and an amine-based compound, wherein the content of sulfur contained in the metal-containing surfactant (B) is 0.2 mass % or more on the basis of the whole amount of the metal-containing surfactant (B); the content of a calcium atom is 0.08 to 0.20 mass % on the basis of the whole amount of the composition; and a mass ratio of the content of the basic compound (C) and the content of a calcium atom derived from the calcium-containing surfactant (b1) [(content of (C))/(calcium content derived from (b1))] is 2.0 or more.

Abstract: A lubricating oil composition that hardly generates precipitation attributable to a molybdenum compound under the low temperature environment and is excellent in a friction-reducing effect under the low temperature environment is provided. The lubricating oil composition is one including (A) a lubricating base oil, (B) a molybdenum-based compound, (C) a metal-based detergent, and (D) an ester compound having one or more hydroxyl groups in a molecule thereof, wherein the metal-based detergent (C) includes (C1) a calcium detergent and (C2) a magnesium detergent, and a content of the ester compound (D) having one or more hydroxyl groups in a molecule thereof is 0.03 to 1.20 mass % on a basis of the total amount of the lubricating oil composition.

Abstract: Provided are a lubricating oil composition for internal combustion engine capable of preventing a deterioration of the combustion state of a spark-ignition internal combustion engine, specifically, a lubricating oil composition to be used for a spark-ignition internal combustion engine in which a total tension per piston of tensions applied to the piston ring is 100 N or less, the lubricating oil composition being a lubricating oil composition including a base oil, (A) a calcium-based detergent, at least one selected from (B1) a sodium-based additive and (B2) a magnesium-based additive, and (C) an ash-free sulfur-based additive in predetermined contents; a method for producing the lubricating oil composition; a spark-ignition internal combustion engine using the lubricating oil composition; and a method for lubricating the internal combustion engine.

Abstract: The lubricating oil composition of the present invention contains, together with a base oil, a viscosity index improver (A) including a comb-shaped polymer (A1), a detergent dispersant (B) including an alkali metal borate (B1) and an organometallic compound (B2) containing a metal atom selected from an alkali metal atom and an alkaline earth metal atom, and a friction modifier (C) including a molybdenum-containing friction modifier, with the total content of an alkali metal atom and an alkaline earth metal atom being 2,000 mass ppm or less. The lubricating oil composition of the present invention has excellent detergency, fuel saving properties, and LSPI-preventing properties.

Abstract: Provided is a lubricating oil composition having excellent detergency and LSPI preventing performance, and specifically a lubricating oil composition including a base oil, a calcium detergent, and a magnesium detergent and/or a sodium detergent, wherein the content of the calcium detergent as converted into a calcium atom and a mass ratio of a magnesium atom (Mg) contained in the magnesium detergent and/or a sodium atom (Na) contained in the sodium detergent to a calcium atom (Ca) [(Mg and/or Na)/Ca] fall within the specific ranges.

Abstract: The lubricating oil composition of the present invention is a lubricating oil composition containing a lubricating base oil, a metal-based detergent, a molybdenum dialkyldithiocarbamate compound, and a boron-containing compound, wherein the metal-based detergent contains a calcium salicylate and at least one selected from the group consisting of a calcium sulfonate and a magnesium-based detergent; the lubricating oil composition arbitrarily contains an ashless friction modifier; the content of a calcium atom is 0.12 to 0.16 mass % on the basis of the whole amount of the lubricating oil composition; the content of a molybdenum atom is 0.05 to 0.10 mass % on the basis of the whole amount of the lubricating oil composition; and a predetermined coefficient X is less than 0.050.

Abstract: A lubricating oil composition that hardly generates precipitation attributable to a molybdenum compound under the low temperature environment and is excellent in a friction-reducing effect under the low temperature environment is provided. The lubricating oil composition is one including (A) a lubricating base oil, (B) a molybdenum-based compound, (C) a metal-based detergent, and (D) an ester compound having one or more hydroxyl groups in a molecule thereof, wherein the metal-based detergent (C) includes (C1) a calcium detergent and (C2) a magnesium detergent, and a content of the ester compound (D) having one or more hydroxyl groups in a molecule thereof is 0.03 to 1.20 mass % on a basis of the total amount of the lubricating oil composition.

Abstract: A lubricating oil composition which exhibits an excellent friction-reducing effect and excellent fuel consumption reducing properties is provided. The lubricating oil composition includes a lubricating base oil (A), a molybdenum compound (B), and an ashless friction modifier (C), wherein the lubricating oil composition includes a binuclear organic molybdenum compound represented by the following general formula (I) as the molybdenum compound (B), with the content of the binuclear organic molybdenum compound as converted into molybdenum atoms being 0.030 mass % or more and 0.140 mass % or less based on the total amount of the lubricating oil composition; and an ester-based ashless friction modifier (C1) and/or an amine-based ashless friction modifier (C2) as the ashless friction modifier (C), with the total content of the ester-based ashless friction modifier (C1) and the amine-based ashless friction modifier (C2) being more than 0.1 mass % and 1.

Abstract: Provided is a lubricating oil composition favorable for reducing friction in a sliding mechanism equipped with a piston ring and a liner, in a device having the sliding mechanism. The lubricating oil composition contains a lubricant base oil, (1) a polymethacrylate and/or an olefin copolymer having a mass-average molecular weight of 100,000 to 600,000, and (2) an ester-type ashless friction modifier and/or an amine-type ashless friction modifier, and has a shear viscosity at 150° C. of 2.3 mPa· or more and less than 3.7 mPa·s.