Abstract: The present invention provides a lubricating oil composition in contact with a silver-containing material, which comprises: a lubricant base oil made of a mineral base oil and/or a synthetic base oil; (A) metallic detergent; (B) one or more species of alkenyl succinimide and/or boron-containing alkenyl succinimide; and (C) zinc dialkyl dithiophosphate, wherein the content of these components to the total mass of the lubricating oil composition are defined as, (A) component: 0.12-2.0 mass % as metal content; (B) component: 0-0.03 mass % as boron content, 0.005 mass % to less than 0.08 mass % as nitrogen content, and the mass ratio (B/N) between the boron content (B) and the nitrogen content (N) is 0-0.55; and (C) component: 0.005-0.10 mass % as phosphorous content. As a lubricating oil in contact with silver-containing material, the lubricating oil composition can inhibit sulfidation corrosion of silver while containing zinc dialkyl dithiophosphate.

Abstract: The present invention provides a lubricating oil composition comprising: a lubricant base oil; and a dialkyl monothiophosphate metal salt, wherein based on the total mass of the lubricating oil composition, the dialkyl monothiophosphate metal salt is contained in an amount of 0.005 to 0.12 mass % in terms of phosphorus; thereby it is possible to provide the lubricating oil composition which can be reduced in the sulfur content and which exhibits excellent friction reduction while maintaining the anti-wear property equivalent to that of the ZnDTP-added oil.

Abstract: The lubricating oil composition of the present invention comprises at least one species of aromatic constituent selected from the following (a1) to (a5): (a1) a lubricating base oil comprising a polycyclic aromatic content of 0.01% by mass or more based on the total amount of base oil (a2) a lubricating base oil comprising a total aromatic content of 20 to 100% by mass based on the total amount of base oil (a3) an aromatic solvent (a4) at least one species of polycyclic aromatic compound selected from alkyl naphthalene and compounds having three or more aromatic rings, and (a5) an aromatic compound having a nitrogen atom, an oxygen atom or a sulfur atom; and an organic molybdenum compound.

Abstract: A lubricating oil composition has excellent oxidation stability, suitable as a lubricating oil for internal combustion engines and automatic transmissions. The lubricating oil composition includes a lubricating base oil and one or more types of phosphorus compound represented by formula (1) as Component (A), the element ratio of sulfur derived from the compound of formula (1) to phosphorus in the oil (S/P molar ratio) being from 0.05 to 0.8 and the amount of phosphorus derived from Component (A) in the oil being from 0.01 to 0.5 percent by mass (in formula 1, R1 through R4 are each a hydrocarbon group with 1 to 30 carbon atoms or an alkylthioethyl group having an alkyl or alkenyl group with 1 to 30 carbon atoms and may be the same or different from one another, X1 to X4 are each independently sulfur or oxygen, and Y represents a metal element).

Abstract: The present invention provides a lubricating oil composition exhibit excellent friction reduction properties with a small amount of molybdenum. The lubricating oil composition comprises a lubricating base oil, (A) a phosphoric acid ester metal salt represented by formula (1) and (B) an organic molybdenum compound with a ratio of molybdenum to sulfur of 1:3.5 or greater. (In formula 1, R1 to R4 are each a hydrocarbon group having 1 to 30 carbon atoms, an alkyl or alkenyl group having 1 to 30 carbon atoms, or an alkylthioethyl comprising an alkyl group having 1 to 30 carbon atoms and may be the same or different from each other; X1, X2, X3 and X4 are each sulfur or oxygen, either X1 or X2 is oxygen or both are oxygen, and either X3 or X4 is oxygen or both are oxygen; and Y is a metal element.

Abstract: The lubricating oil composition of the present invention comprises at least one species of aromatic constituent selected from the following (a1) to (a5): (a1) a lubricating base oil comprising a polycyclic aromatic content of 0.01% by mass or more based on the total amount of base oil (a2) a lubricating base oil comprising a total aromatic content of 20 to 100% by mass based on the total amount of base oil (a3) an aromatic solvent (a4) at least one species of polycyclic aromatic compound selected from alkyl naphthalene and compounds having three or more aromatic rings, and (a5) an aromatic compound having a nitrogen atom, an oxygen atom or a sulfur atom; and an organic molybdenum compound.

Abstract: Provided are a lubricant composition capable of reducing friction between sliding parts at least one of which contains an aluminum-based material in a lubrication section, and a method for lubricating an aluminum-based member with the composition. The lubricant composition is for use in a lubrication section having sliding parts at least one of which contains an aluminum-based material, and contains a lubricant base oil and at least one of a phosphorus-containing carboxylic compound and a metal salt thereof (component (A)) at 0.001 to 1 mass % of the composition in terms of phosphorus. The composition may suitably be used as lubricant such as drive train lubricant for automatic or manual transmissions, grease, wet brake oil, hydraulic actuation oil, turbine oil, compressor oil, bearing oil, refrigerant oil, and the like used in apparatus having the sliding parts.

Abstract: Lubricating oil compositions have low friction properties and anti-wear properties and are excellent in long drain capability. The lubricating oil compositions are particularly suitable for use as a fuel efficient type lubricating oil for internal combustion engines. The lubricating oil compositions contain a lubricating oil additive comprising one or more compounds selected from a specific nitrogen-containing compound, an acid-modified derivative thereof, and an oil soluble metal complex obtained by mixing the nitrogen-containing compound and/or acid-modified derivative thereof with an organic metal salt and/or organic metal complex.

Abstract: The lubricating oil composition of the present invention comprises a base oil for lubricating oil, (A) at least one species selected from the phosphorus compounds represented by the following General Formula (1) or (2) as well as metal salts (excluding molybdenum salts) and amine salts thereof, and (B) an organic molybdenum compound not containing sulfur as a constituent element (in the formula, R1 and R4 represent hydrocarbon groups having 1 to 30 carbons, R2, R3, R5 and R6 represent hydrogen atoms or hydrocarbon groups having 1 to 30 carbons, X1 to X7 represent oxygen atoms or sulfur atoms, and n represents 0 or 1).

Abstract: The present invention provides a lubricating oil composition comprising: a lubricant base oil; and a dialkyl monothiophosphate metal salt, wherein based on the total mass of the lubricating oil composition, the dialkyl monothiophosphate metal salt is contained in an amount of 0.005 to 0.12 mass % in terms of phosphorus; thereby it is possible to provide the lubricating oil composition which can be reduced in the sulfur content and which exhibits excellent friction reduction while maintaining the anti-wear property equivalent to that of the ZnDTP-added oil.

Abstract: An additive composition is provided for a lubricating oil that is easy to produce, does not have adverse effects, such as causing rubber seals to swell, and is excellent in storage stability. The additive composition contains a metal salt of a phosphorus-containing compound represented by formula (1) in an amount of 10 to 90 percent by mass of the composition, contained in a hydrocarbon solvent selected from a mineral oil, a hydrocarbon synthetic oil and a mixture thereof, the hydrocarbon solvent having a 100° C. kinematic viscosity of 0.5 to 4.5 mm2/s, a % CA of 3 or less, and a sulfur content of 0.05 percent by mass or less: wherein X1 and X2 are each independently oxygen or sulfur, R1, R2, R3, and R4 are each independently a straight-chain alkyl group having 3 to 12 carbon atoms, the average of the carbon number is 5 or greater, and M is a divalent metal atom.

Abstract: The present invention provides a low ash engine oil composition which, despite the low ash content, has engine detergency which enables the composition to pass severe detergency tests for diesel engine oils. The engine oil composition contains 0.6 percent by mass or less of a sulfated ash and comprises a low ash engine oil composition with a sulfated ash content of 0.6 percent by mass or less, which comprises: a lubricating base oil with a % CA of 2 or less, a kinematic viscosity at 40° C. of 25 mm2/s or less and a viscosity index of 120 or greater; a viscosity index improver contained in such an amount that the viscosity index of the composition will be 160 or greater; (A) a metallic detergent with a metal ratio of 3 or less; and/or (B) a sulfur-free phosphorus compound.

Abstract: The present invention provides a lubricating oil composition in contact with a silver-containing material, which comprises: a lubricant base oil made of a mineral base oil and/or a synthetic base oil; (A) metallic detergent; (B) one or more species of alkenyl succinimide and/or boron-containing alkenyl succinimide; and (C) zinc dialkyl dithiophosphate, wherein the content of these components to the total mass of the lubricating oil composition are defined as, (A) component: 0.12-2.0 mass % as metal content; (B) component: 0-0.03 mass % as boron content, 0.005 mass % to less than 0.08 mass % as nitrogen content, and the mass ratio (B/N) between the boron content (B) and the nitrogen content (N) is 0-0.55; and (C) component: 0.005-0.10 mass % as phosphorous content. As a lubricating oil in contact with silver-containing material, the lubricating oil composition can inhibit sulfidation corrosion of silver while containing zinc dialkyl dithiophosphate.

Abstract: The lubricating oil composition of the present invention comprises at least one species of aromatic constituent selected from the following (a1) to (a5): (a1) a lubricating base oil comprising a polycyclic aromatic content of 0.01% by mass or more based on the total amount of base oil (a2) a lubricating base oil comprising a total aromatic content of 20 to 100% by mass based on the total amount of base oil (a3) an aromatic solvent (a4) at least one species of polycyclic aromatic compound selected from alkyl naphthalene and compounds having three or more aromatic rings, and (a5) an aromatic compound having a nitrogen atom, an oxygen atom or a sulfur atom; and an organic molybdenum compound.

Abstract: Disclosed are lubricating oil compositions excellent in friction reducing effect and long drain properties and particularly suitable for internal combustion engines, which comprise a lubricating base oil, a specific phosphorus compound in an amount of 0.005 to 0.5 percent by mass in terms of phosphorus based on the total mass of the composition, and at least one additive selected from the group consisting of (C) metallic detergents, (D) ashless dispersants, and (E) anti-oxidants, and further contains (F) a sulfur-containing organic molybdenum complex and (G) an ashless friction modifier and which satisfy prescribed requirements and have a sulfated ash content not exceeding a specified level.

Abstract: Disclosed are lubricating oil additives obtained by dissolving or reacting (A) a metal salt of a specific phosphorus compound which is insoluble or less soluble in lubricating oils in or with (B) an amine compound so as to be solved in the lubricating oils; a lubricating oil composition containing such an additive; a method of producing the additive and composition.

Abstract: A lubricating oil composition is disclosed which comprises a lubricating base oil, (A) at least one type of compound selected from specific phosphoric acid esters and salts thereof or in combination with (B) at least one type of compound selected from specific metal salts of specific phosphoric acid esters, with excellent oxidation stability, base number retention properties, anti-wear properties, extreme pressure properties and anti-corrosion properties and thus can be suitably used, in particular, as a lubricating oil for an internal combustion engine.

Abstract: The present invention provides a lubricating oil composition for an internal combustion engine which is very good in base number retention property, detergency at high temperature and valve train anti-wear property and does not substantially contain phosphorus- and/or sulfur-containing anti-wear agent. The composition comprises a lubricant base oil comprising a mineral oil and/or a synthetic oil, (A) 0.001 to 0.5% by mass of an ester of a boric acid in terms of boron element therein and (B) 0.01 to 5% by mass of an ashless antioxidant, wherein said composition contains substantially no metal salts of dithiophosphoric acid and has a sulfur content of 0.2% by mass or less, each percentage being based on a total mass of the composition.

Abstract: The present invention provides a lubricating oil composition, comprising: a lubricant base oil having a sulfur content adjusted to 0.1% or less by mass; and (A) one or more alkali metal or alkaline earth metal salicylates in which the ratio of a salicylate constituent having, in the 3-and 5-positions, hydrocarbon groups having 1 to 40 carbon atoms is adjusted to 10% or more by mol and/or (B) one or more alkali metal or alkaline earth metal salicylates in which the ratio of one or more monoalkylsalicylate constituents is adjusted to 85% or more by mol and the ratio of a monoalkylsalicylate constituent having, in the 3-position, a secondary alkyl group having 10 or more and less than 20 carbon atoms is adjusted to 50% or more by mol, the (A) and/or (B) being incorporated into the base oil in an amount of 0.005 to 5% by mass of the total of the composition, and the amount being an amount in terms of the metal element therein. In this way, the oxidation life under the contamination of water content is improved.

Abstract: A lubricating oil additive and a lubricating oil composition wherein no precipitation is generated to exhibit a good storage stability even if a combination of a salicylate detergent and another metal detergent is used is provided by rendering the additive and composition an additive and a composition obtained by incorporating, into a lubricant base oil, (A) an alkali metal or alkaline earth metal salicylate having at its 3 and 5-positions hydrocarbon groups having 1 to 40 carbon atoms and a (per)basic salt, and (B) a metal detergent other than any salicylate detergent.