Abstract: The invention addresses a problem of providing a lubricating oil composition for gas engines capable of suppressing viscosity increase while reducing a sulfated ash content and excellent in high-temperature detergency and base number retention. The lubricating oil composition is used for gas engines and contains a base oil (A), at least one ash-free additive (B) selected from an ash-free sulfur-based antioxidant (B1) and a hindered amine compound (B2), and a boronated imide-type dispersant (C), and satisfies the following requirements (X1) to (X3): Requirement (X1): the sulfated ash content is 0.2% by mass or less. Requirement (X2): the content of the ash-free additive (B) is 1.2% by mass or less based on the total amount of the lubricating oil composition, provided that in the case where the ash-free additive (B) contains the hindered amine compound (B2), the content of the hindered amine compound (B2) is less than 1.0% by mass based on the total amount of the lubricating oil composition.

Abstract: Provided is a lubricating oil composition for use in internal-combustion engines, containing a base oil (A), an ashless dispersant (B) containing a non-boronated alkenylsuccinic acid imide (B1) and a boronated alkenylsuccinic acid imide (B2), a thiadiazole compound (C), and an aromatic carboxylate (D) having one or more hydroxy groups, wherein the content of the component (C) is 0.2 to 1.2% by mass based on the total amount of the lubricating oil composition, the content of a zinc dithiophosphate is, as calculated in terms of zinc atoms, less than 500 ppm by mass based on the total amount of the lubricating oil composition, and the content of a metal-based detergent is, as calculated in terms of metal atoms, less than 600 ppm by mass based on the total amount of the lubricating oil composition.

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: The present invention provides a lubricating oil composition including a viscosity index improver (A) containing a comb-shaped polymer and having an SSI (shear stability index) of 30 or less together with a base oil, wherein an HTHS viscosity (high temperature high shear viscosity) at 150° C. (T150) is 1.6 to 2.9 mPa·s, and a ratio of a kinematic viscosity at 40° C. (V40) [mm2/s] to the HTHS viscosity at 150° C. (T150) [mPa·s] (V40/T150) is 12.4 or less. The lubricating oil composition of the present invention is excellent in fuel consumption reducing properties in a low-temperature region assuming the time of starting an engine while making various properties, such as a viscosity, etc., in a high-temperature region assuming the time of high-speed operation of an engine favorable.

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 for an internal combustion engine according to the present invention contains a lubricating base oil, (A1) a basic calcium salicylate having a TBN of 200 mgKOH/g or more, (A2) a basic sodium sulfonate having a TBN of 200 mgKOH/g or more and/or a basic calcium sulfonate having a TBN of 50 mgKOH/g or less, (B) a binuclear organic molybdenum compound and/or a trinuclear organic molybdenum compound, and (C) a polyalkyl (meth)acrylate having an SSI of 30 or less, a total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds being 0.025 mass % or more relative to the whole amount of the composition and the lubricating oil composition having predetermined values of a high-temperature high-shear viscosity and a NOACK value (250° C., 1 hr).

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 for an internal combustion engine of the invention contains (A) a lubricant base oil composed of a mineral oil and/or a synthetic oil, (B) a boron-containing alkenylsuccinimide and/or a boron-containing alkylsuccinimide in an amount of 0.001 to 0.1% by mass as a boron-equivalent amount based on the total amount of the composition, and (C) a poly(meth)acrylate in an amount of 0.1 to 30% by mass based on the total amount of the composition, and the poly(meth)acrylate has Mw of 100,000 to 700,000 and Mw/X of 30,000 or more, in which the weight-average molecular weight thereof is represented by Mw and the mean carbon number of the alkyl groups therein, as measured through 13C-NMR, is represented by X.

Abstract: The present invention provides a lubricating oil composition including a viscosity index improver (A) containing a comb-shaped polymer and having an SSI (shear stability index) of 30 or less together with a base oil, wherein an HTHS viscosity (high temperature high shear viscosity) at 150° C. (T150) is 1.6 to 2.9 mPa·s, and a ratio of a kinematic viscosity at 40° C. (V40) [mm2/s] to the HTHS viscosity at 150° C. (T150) [mPa·s] (V40/T150) is 12.4 or less. The lubricating oil composition of the present invention is excellent in fuel consumption reducing properties in a low-temperature region assuming the time of starting an engine while making various properties, such as a viscosity, etc., in a high-temperature region assuming the time of high-speed operation of an engine favorable.

Abstract: A lubricating oil composition of the present invention for an internal combustion engine is prepared by blending (A) a perbasic calcium sulfonate and/or a perbasic calcium phenate having a TBN of 200 mgKOH/g or higher, (B) predetermined binuclear and/or trinuclear organic molybdenum compounds, and (C) a polyalkyl (meth)acrylate having an SSI of 30 or lower into a lubricating base oil composed of a mineral oil and/or a synthetic oil, in which the total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds is 0.025% by mass or higher based on the total amount of the composition, and in which the lubricating oil composition has a high-temperature high-shear viscosity at 100° C. of 4.0 to 5.0 mPa·s, a high-temperature high-shear viscosity at 150° C. of 2.5 mPa·s or lower and a NOACK value (250° C., 1 hr) of 15% by mass or less.

Abstract: A lubricating oil composition for an internal combustion engine according to the present invention contains a lubricating base oil, (A1) a basic calcium salicylate having a TBN of 200 mgKOH/g or more, (A2) a basic sodium sulfonate having a TBN of 200 mgKOH/g or more and/or a basic calcium sulfonate having a TBN of 50 mgKOH/g or less, (B) a binuclear organic molybdenum compound and/or a trinuclear organic molybdenum compound, and (C) a polyalkyl (meth)acrylate having an SSI of 30 or less, a total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds being 0.025 mass % or more relative to the whole amount of the composition and the lubricating oil composition having predetermined values of a high-temperature high-shear viscosity and a NOACK value (250° C., 1 hr).

Abstract: The lubricating oil composition for spark-ignition internal combustion engine according to the present invention is a lubricating oil composition to be used for a spark-ignition internal combustion engine including a piston having a piston ring, in which a total tension per piston of tensions applied to the piston ring is 30 N or less, the lubricating oil composition being a lubricating oil composition comprising a base oil, (A) an organic metal-based additive containing an alkali metal and/or an alkaline earth metal, and (B) an organic zinc-based additive, wherein a concentration of the component (A) on a basis of the total amount of the lubricating oil composition is 0.15% by mass or less as converted into a metal content; a concentration of the component (B) on a basis of the total amount of the lubricating oil composition is 0.

Abstract: A lubricating oil composition of the present invention for an internal combustion engine is prepared by blending (A) a perbasic calcium sulfonate and/or a perbasic calcium phenate having a TBN of 200 mgKOH/g or higher, (B) predetermined binuclear and/or trinuclear organic molybdenum compounds, and (C) a polyalkyl (meth)acrylate having an SSI of 30 or lower into a lubricating base oil composed of a mineral oil and/or a synthetic oil, in which the total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds is 0.025% by mass or higher based on the total amount of the composition, and in which the lubricating oil composition has a high-temperature high-shear viscosity at 100° C. of 4.0 to 5.0 mPa·s, a high-temperature high-shear viscosity at 150° C. of 2.5 mPa·s or lower and a NOACK value (250° C., 1 hr) of 15% by mass or less.

Abstract: To provide a desulfurizing agent which can efficiently desulfurize a liquid fuel containing organic sulfur compounds at 80° C. or lower so as to attain a considerably low sulfur content, so that hydrogen can be produced from the desulfurized fuel through steam reforming, autothermal reforming, or partial-oxidation reforming, and that poisoning of a reforming catalyst employed in the reforming processes can be prevented. The desulfurizing agent for hydrocarbon compounds, including a porous carrier and Ag supported on the carrier, wherein the amount of Ag supported on the carrier is 0.5 to 50 mass %, and the ratio of amount by mole of nitrogen contained in the agent to amount by mole of Ag is 10 to 100%.

Abstract: The invention provides a carbon monoxide conversion method for hydrogen-containing gas. The method comprises selective CO conversion in hydrogen-containing gas through contact of CO with steam and oxygen in the presence of a catalyst containing copper, alumina and zinc oxide.