Lubricant compositions comprising a base oil, one or more antioxidants selected from a group consisting of N-α-naphthyl-N-phenylamine antioxidants and diphenylamine antioxidants; and a sulfur-containing additive comprising up to seven carbon atoms exhibit outstanding oxidative stability and non-corrosion properties. The N-α-naphthyl-N-phenylamine antioxidants plus diphenylamine antioxidants in total may be present from about 0.2 wt % to about 0.8 wt %, based on the total weight of the lubricant composition. The sulfur provided by the sulfur-containing additive may be present from about 50 ppm to about 1000 ppm by weight, based on the total weight of the lubricant composition.

The present invention relates to a dinuclear molybdenum complex with ligands selected from fatty tertiary amines of formula (I):
R—N[(CH.sub.2).sub.nR.sup.2][(CH.sub.2).sub.nR.sup.3]  (I)
wherein R represents a linear or branched alkyl comprising 3 to 30 carbon atoms, preferably 3 to 20, advantageously 7 to 17 carbon atoms; n, identical or different, represents 2 or 3; R.sup.2 and R.sup.3, identical or different, represent an O, OR, NR′.sub.2, COOR′, or COO group, where R′, identical or different, represents a hydrogen atom or an alkaline or alkaline earth metal, preferably R′ is H, preferably R.sup.2 and R.sup.3, identical or different, represent an OH or NH.sub.2 group.

Alkyl salicylic acids, overbased detergents derived from alkyl salicylic acids, lubricating compositions including the alkyl salicylic acids and/or overbased detergents, and processes of making and using the same, are described.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an ashless dispersant. The ashless dispersant may be selected from succinimide compounds prepared from aliphatic or aromatic amines.

The present disclosure describes lubricant compositions effective to minimize average engine sludge through selection of lubricant additives that control the total nitrogen as well as the origin of the nitrogen in the lubricant composition. In aspects, the lubricant compositions herein include at least a base oil of lubricating viscosity, a dispersant system, and at least one antioxidant.

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 including a base oil (X) having a tertiary carbon atom at a content of 8.0 at % or more based on the total carbon of hydrocarbons and an antioxidant (Y) having an amine-based antioxidant (A), a phenol-based antioxidant (B), and a phosphor-based antioxidant (C). The amine-based antioxidant (A) includes a diphenylamine compound (A1) represented by the following general formula (a1):

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where R.sup.a1 and R.sup.a2, na1 and na2 are defined in the disclosure.

The present invention provides a water-glycol hydraulic fluid composition comprising an alkanolamine compound according to the general formula (1), wherein the water-glycol hydraulic fluid composition comprises 20-60% by mass water, 20-60% by mass glycol, 0.6-1.2% by mass fatty acid lubricant, and 0.01-0.06% by mass alkaline hydroxide compound selected from potassium hydroxide and/or sodium hydroxide, and has an alkali reserve of 10-25, wherein R.sub.1 and R.sub.2 are hydrocarbon groups having from 1 to 8 carbon atoms, and R.sub.3 is a hydrocarbon group having 2 or more carbon atoms.

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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 R.sup.1 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.

The invention relates to a grease composition having a base oil and a thickener that includes hydrophilic metal oxide particles and one or more amines that contain one or more unsaturated C—C bonds and/or at least one OH group. The hydrophilic metal oxide particles have a BET specific surface area of at least 10 m.sup.2/g and at least 80% of the hydrophilic metal oxide particles have a particle size in the range of from 5 nm to 900 μm. The amount of the thickener is in the range of from 0.1-40% by weight, based on the total weight of the grease composition. The invention further relates to methods for manufacturing the grease composition, and the use of the grease composition for lubricating bearings, gears and couplings.