A lubricating oil composition includes at least one base oil selected from the group consisting of a mineral oil-based lubricating oil, a synthetic oil-based lubricating oil, and a mixed oil thereof, zinc dialkyldithiophosphate X represented by Formula (1), and an acid phosphate ester amine salt Y represented by Formula (2), in which a content P.sub.X of the X is from 0.06% by mass to 0.08% by mass in terms of phosphorus concentration with respect to a total mass of the lubricating oil composition, and a content P.sub.Y of the Y is from 0.015% by mass to 0.025% by mass in terms of phosphorus concentration with respect to the total mass of the lubricating oil composition.

A complex including an active ingredient, and a surfactant. The active ingredient is one or more less-oil-soluble substances selected from the group consisting of a hardly-oil-soluble substance and an oil-insoluble substance, and the one or more less-oil-soluble substances function as an additive for lubricating oil. A method of making the complex.

Provided is a water-soluble metalworking oil comprising a base oil (A) comprising oil-soluble polyalkylene glycol (A1), wherein a total content of water-soluble polyalkylene glycol and methoxypolyethylene glycol is less than 60% by mass based on the total amount excluding water.

A water-soluble metalworking oil may include 0.7% by mass or more of 2-phenoxyethanol (A), based on the total water-soluble metalworking oil mass. A content of petroleum sulfonate may be less than 10 parts by mass, based on 100 parts by mass of the 2-phenoxyethanol (A). The 2-phenoxyethanol (A) may be present in a range of from 0.7 to less than 5.0% by mass. The water-soluble metalworking oil may further include: an amine, a fatty acid (C), and/or a nonionic surfactant (D).

A lithium-based grease and the preparation method thereof are provided. The raw materials for preparing the lithium-based grease include in parts by weight: 75-88 parts of base oil, 0.5-2.5 parts of antiwear agent, 0.1-1.5 parts of antirust agent, 0.1-1.5 parts of antioxidant, 5-25 parts of lubricant, 5-15 parts of thickening agent, and 0.6-2.0 parts of saponifying agent. The raw materials also include hydroxyl compound-containing modified graphene containing quaternary ammonium salt or aromatic ring. The grease has good colloid stability and mechanical stability, can greatly improve the antiwear property. More than that, the grease has excellent oxidation resistance, and can significantly shorten the reaction time of the saponification, reduce the reaction temperature of the saponification.

The disclosure relates to a biobased metal-working fluid (MWF) composition and method for making same, and more particularly metal-working fluid with biobased lubricants with improved emulsion stability. At least 50 wt. % of the base oil component in the MWF concentrate is a plant-derived liquid decarboxylated rosin acid oil (“DCR”). The DCR comprises 50 to 100 wt. % of tricyclic compounds having 18-20 carbon atoms, one or more C═C groups, and m/z (mass/charge) value of 220-280; an oxygen content of <5%; a density of 0.9 to 1.0 g/cm.sup.3 at 20° C.; and an acid value of <10 mg KOH/g. The resulting MWF is characterized as having comparable if not better performance compared to a MWF containing only mineral oil (e.g., Group I or Group II).

An aspect of the present invention relates to a lubricant composition containing at least: (A) 50 to 80 mass % of silicone oil represented by formula (1) below, and having a mass-average molecular weight of 900 to 4000, a ratio (C/Si ratio) of carbon to silicon of 3.03 or higher in the structure, and a viscosity index (VI) of 300 or higher; (B) 10 to 49 mass % of hydrocarbon-based lubricant; and (C) 1 to 10 mass % of antioxidant.

Disclosed are solvency enhancer compositions, for example, as additives to lubricating oils and as formulated in lubricating oil compositions and associated methods of preparation and use thereof. The compositions and methods can dissolve at least one of oxidation products and other organic polar compounds, due to lubricant degradation, formed and suspended in oil compositions including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols. Further described are methods for dissolving organic deposits in an oil system including adding an effective amount of a solvency enhancer to the oil system, wherein the solvency enhancer includes Guerbet alcohols. Also provided are methods for preventing sludge and varnish formation in in-service oils including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols.

Brine-tolerant lubricants are provided. The brine-tolerant lubricants may comprise an oil component, a surfactant component, and, optionally, an additive component. In one aspect, the oil component comprises a fatty acid alkyl ester. In one aspect, the surfactant component comprises at least one of an alkoxylated fatty acid and an alkoxylated fatty alcohol. Also provided are methods for increasing the lubricity of a drilling fluid by contacting the drilling fluid with the brine-tolerant lubricants.

The present disclosure provides a lubricating oil concentrate containing an ethoxylated ether amine and a base oil. The lubricating oil concentrate is capable of forming a stable, low foaming emulsion when added to an aqueous medium and may be useful in metalworking and cleaning fluids.