Abstract: A method for utilizing a lubricating oil composition in which the content of a metal-based cleaning agent (X) having a base value of 100 mgKOH/g or less is 630 mass ppm or less in terms of metal atoms, and the content of sulfated ash is 1.5 mass % or less. The method includes measuring at least one physical property value among the capacitance and the dielectric constant of the lubricating oil composition while using the lubricating oil composition, and evaluating the progress of degradation of the lubricating oil composition.

Abstract: A dispersant for a lubricating oil, containing at least one compound selected from a specific nitrogen-containing compound which is obtained by using, as raw materials, (A) at least one polyolefin selected from polybutene and polyisobutene, (B) at least one maleic acid compound selected from maleic acid and maleic anhydride, and (C) polyamine; a boride of the specific nitrogen-containing compound; and an acylated product of the specific nitrogen-containing compound. The polyolefin (A) satisfies at least one of the following conditions (?) and (?). (?) a ratio (Sb/Sa) of an integrated value (Sb) of a peak present at 4.40 to 5.00 ppm in a 1H-NMR spectrum to an integrated value (Sa) of a peak present at 5.01 to 5.60 ppm in the 1H-NMR spectrum is 2 or more. (?) a ratio (Sd/Sc) of an integrated value (Sd) of a peak present at 1.76 to 2.10 ppm in the 1H-NMR spectrum to an integrated value (Sc) of a peak present at 1.65 to 1.75 ppm in the 1H-NMR spectrum is 1 or more.

Abstract: Provided is a mineral base oil satisfying the following requirements (I) to (III): Requirement (I): a kinematic viscosity at 100° C. is 2 mm2/s or more and less than 7 mm2/s; Requirement (II): a viscosity index is 100 or more; and Requirement (III): a temperature gradient ?|?*| of complex viscosity between two temperature points ?10° C. and ?25° C. is 60 Pa·s/° C. or less as measured with a rotary rheometer under conditions at an angular velocity of 6.3 rad/s and a strain amount of 0.1 to 100%. The foregoing mineral base oil can become a lubricating oil composition having desirable low-temperature viscosity characteristics, including low-temperature fuel consumption and low-temperature engine start-up performance, and also having excellent high-temperature piston detergency.

Abstract: The present invention provides a lubricating oil composition for two-wheeled vehicles, which is able to not only suppress a lowering of fatigue life of engine parts while making fuel saving properties (in particular, fuel saving properties at the time of low speed) favorable but also make clutch friction characteristics of two-wheeled vehicles favorable. The present invention is concerned with a lubricating oil composition for two-wheeled vehicles, including a base oil (A) having a viscosity index of 120 or more, an ethylene-propylene copolymer (B), and a metal-based detergent (C), wherein the content of the ethylene-propylene copolymer (B) is 0.

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: A dispersant for a lubricating oil, containing at least one compound selected from a specific nitrogen-containing compound which is obtained by using, as raw materials, (A) at least one polyolefin selected from polybutene and polyisobutene, (B) at least one maleic acid compound selected from maleic acid and maleic anhydride, and (C) polyamine; a boride of the specific nitrogen-containing compound; and an acylated product of the specific nitrogen-containing compound. The polyolefin (A) satisfies at least one of the following conditions (?) and (?). (?) a ratio (Sb/Sa) of an integrated value (Sb) of a peak present at 4.40 to 5.00 ppm in a 1H-NMR spectrum to an integrated value (Sa) of a peak present at 5.01 to 5.60 ppm in the 1H-NMR spectrum is 2 or more. (?) a ratio (Sd/Sc) of an integrated value (Sd) of a peak present at 1.76 to 2.10 ppm in the 1H-NMR spectrum to an integrated value (Sc) of a peak present at 1.65 to 1.75 ppm in the 1H-NMR spectrum is 1 or more.

Abstract: The present invention provides a mineral base oil having a kinetic viscosity at 100° C. of 7 mm2/s or more and less than 10 mm2/s, a viscosity index of 100 or more, and a temperature gradient ?|?*| complex viscosity between two temperature points of ?5° C. and ?15° C. of 240 mPa·s/° C. or less as measured with a rotary rheometer at an angular velocity of 6.3 rad/s. The use of the mineral base oil enables easy preparation of a lubricating oil composition and a grease composition having excellent oxidation stability while ensuring the freedom of selection of additives.

Abstract: The present invention provides a lubricating oil composition for two-wheeled vehicles, which is able to not only suppress a lowering of fatigue life of engine parts while making fuel saving properties (in particular, fuel saving properties at the time of low speed) favorable but also make clutch friction characteristics of two-wheeled vehicles favorable. The present invention is concerned with a lubricating oil composition for two-wheeled vehicles, including a base oil (A) having a viscosity index of 120 or more, an ethylene-propylene copolymer (B), and a metal-based detergent (C), wherein the content of the ethylene-propylene copolymer (B) is 0.

Abstract: Disclosed herein is a mineral base oil satisfying the following requirements (I) to (V): (I): a kinematic viscosity at 100° C. is 2 mm2/s or more and less than 7 mm2/s; (II): a viscosity index is 100 or more; (III): a temperature gradient ?|?*| of complex viscosity between two points of ?10° C. and ?25° C. is 60 Pa·s/° C. or less as measured with a rotary rheometer under conditions at an angular velocity of 6.3 rad/s and a strain amount of 0.1 to 100%; (IV): a content ratio [R1/R2] of a monocyclo paraffin component (R1) to a dicyclo to hexacyclo paraffin component (R2) is 0.70 or less by a volume ratio as measured in accordance with ASTM D2786; and (V): a % CA is less than 1.0.

Abstract: The present invention provides a mineral base oil having a kinetic viscosity at 100° C. of 7 mm2/s or more and less than 10 mm2/s, a viscosity index of 100 or more, and a temperature gradient ?|?*| complex viscosity between two temperature points of ?5° C. and ?15° C. of 240 mPa·s/° C. or less as measured with a rotary rheometer at an angular velocity of 6.3 rad/s. The use of the mineral base oil enables easy preparation of a lubricating oil composition and a grease composition having excellent oxidation stability while ensuring the freedom of selection of additives.

Abstract: Provided is a mineral base oil satisfying the following requirements (I) to (III): Requirement (I): a kinematic viscosity at 100° C. is 2 mm2/s or more and less than 7 mm2/s; Requirement (II): a viscosity index is 100 or more; and Requirement (III): a temperature gradient ?|?*| of complex viscosity between two temperature points ?10° C. and ?25° C. is 60 Pa·s/° C. or less as measured with a rotary rheometer under conditions at an angular velocity of 6.3 rad/s and a strain amount of 0.1 to 100%. The foregoing mineral base oil can become a lubricating oil composition having desirable low-temperature viscosity characteristics, including low-temperature fuel consumption and low-temperature engine start-up performance, and also having excellent high-temperature piston detergency.

Abstract: Provided is a lubricating oil composition to be used in an internal combustion engine having a sliding mechanism including a piston ring and a liner, the lubricating oil composition including: a base oil; (A) a poly(meth)acrylate; and (B) an organic molybdenum compound, in which: (A) the poly(meth)acrylate contains a polymer (A1) including a repeating unit derived from a (meth)acrylate represented by the following formula (1) and having a mass-average molecular weight of from 1,000 to 500,000; and a content of (B) the organic molybdenum compound in a total amount of the composition is from 0.01 mass % to 0.2 mass % in terms of a molybdenum atom: wherein R1 represents a hydrogen atom or a methyl group, and X represents a hydrogen atom, a hydrocarbon group having 1 to 60 carbon atoms, or a functional group-containing hydrocarbon group having 1 to 60 carbon atoms.

Abstract: Disclosed is a lubricating oil composition for low-friction sliding materials, which is used in a sliding mechanism where a DLC film containing hydrogen in an amount of from 5 atom % to 50 atom % is formed on at least one sliding surface. The lubricating oil composition contains, in the lubricant base oil therein and based on the total amount of the composition, (A) an organic zinc dithiophosphate in an amount of from 0.005% by mass to 0.12% by mass in terms of the phosphorus concentration therein, (B) an amine-based friction-reducing agent in an amount of from 0.05% by mass to 5.0% by mass, and (C) an alkaline earth metal salicylate-based detergent and/or an alkaline earth metal sulfonate-based detergent in an amount of from 0.05% by mass to 0.5% by mass in terms of the alkaline earth metal concentration therein, wherein the component (A) contains, based on the total amount of the composition, a zinc primary dialkyldithiophosphate in an amount of from 0.005% by mass to 0.

Abstract: Disclosed is a lubricating oil composition for low-friction sliding materials, which is used in a sliding mechanism where a DLC film containing hydrogen in an amount of from 5 atom % to 50 atom % is formed on at least one sliding surface. The lubricating oil composition contains, in the lubricant base oil therein and based on the total amount of the composition, (A) an organic zinc dithiophosphate in an amount of from 0.005% by mass to 0.12% by mass in terms of the phosphorus concentration therein, (B) an amide-based friction-reducing agent in an amount of from 0.05% by mass to 5.0% by mass, and (C) an alkaline earth metal salicylate-based detergent and/or an alkaline earth metal sulfonate-based detergent in an amount of from 0.05% by mass to 0.5% by mass in terms of the alkaline earth metal concentration therein.

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.

Abstract: The present invention provides a lubricating oil composition for internal combustion engine exhibiting excellent fuel-saving performance for a long period of time. The lubricating oil composition for internal combustion engine is characterized by containing a base oil having a kinematic viscosity as measured at 100° C. of 2 to 10 mm2/s, an aromatic content (% CA) of 3 or less, and a sulfur content of 300 ppm by mass or less, and the following additives: (1) an alkaline earth metal salicylate-based detergent in an amount of 0.3 to 1.5 mass % as reduced to sulfated ash; (2) a zinc dihydrocarbyldithiophosphate in an amount of 0.03 to 0.10 mass % as reduced to phosphorus; (3) a succinimide-based ashless dispersant having a molecular weight of 500 to 4,000, and an alkenyl group or an alkyl group in an amount of 0.05 to 0.20 mass % as reduced to nitrogen; (4) a phenol-based ashless antioxidant in an amount of 0.05 to 3.0 mass %; (5) an amine-based ashless antioxidant in an amount of 0.05 to 3.

Abstract: A lubricating oil composition of the invention contains: a lubricating base oil; a component (A) that is a polymethacrylate having a mass average molecular weight in a range from 30,000 to 600,000; and a component (B) that is an olefin copolymer having a 95% weight-loss temperature of 500 degrees C. or less as calculated by differential thermal analysis and having 40 or less of SSI (Shear Stability Index).

Abstract: Disclosed is a lubricating oil composition for low-friction sliding materials, which is used in a sliding mechanism where a DLC film containing hydrogen in an amount of from 5 atom % to 50 atom % is formed on at least one sliding surface. The lubricating oil composition contains, in the lubricant base oil therein and based on the total amount of the composition, (A) an organic zinc dithiophosphate in an amount of from 0.005% by mass to 0.12% by mass in terms of the phosphorus concentration therein, (B) an amine-based friction-reducing agent in an amount of from 0.05% by mass to 5.0% by mass, and (C) an alkaline earth metal salicylate-based detergent and/or an alkaline earth metal sulfonate-based detergent in an amount of from 0.05% by mass to 0.5% by mass in terms of the alkaline earth metal concentration therein, wherein the component (A) contains, based on the total amount of the composition, a zinc primary dialkyldithiophosphate in an amount of from 0.005% by mass to 0.

Abstract: Disclosed is a lubricating oil composition for low-friction sliding materials, which is used in a sliding mechanism where a DLC film containing hydrogen in an amount of from 5 atom % to 50 atom % is formed on at least one sliding surface. The lubricating oil composition contains, in the lubricant base oil therein and based on the total amount of the composition, (A) an organic zinc dithiophosphate in an amount of from 0.005% by mass to 0.12% by mass in terms of the phosphorus concentration therein, (B) an amide-based friction-reducing agent in an amount of from 0.05% by mass to 5.0% by mass, and (C) an alkaline earth metal salicylate-based detergent and/or an alkaline earth metal sulfonate-based detergent in an amount of from 0.05% by mass to 0.5% by mass in terms of the alkaline earth metal concentration therein.

Abstract: Provided by the present invention is a lubricating oil composition showing a very low frictional coefficient when used as a lubricating oil for a low friction sliding material prepared by blending with an additive selected from a specific phosphorus-zinc-containing compound and a specific sulfur-containing compound, and a sliding mechanism having an excellent low frictional property in which a DLC film containing 5 to 50 atom % of hydrogen is formed or a sliding mechanism having an excellent low frictional property in which 1 to 30 atom % of tungsten (W) or molybdenum (Mo) is contained is provided by combining the above lubricating oil composition with a sliding member having a film of a specific low frictional sliding material on a sliding face.