The disclosure relates to viscosity improver concentrates comprising a bio-based liquid decarboxylated rosin acid as a solubilizer, and a viscosity index improver. The viscosity improver concentrate is used in lubricating oil compositions comprising base oil and optional additives. The decarboxylated rosin acid component has at least one or more of: one or more CC groups, and 40-100 wt. % of tricyclic compounds having 18-20 carbon atoms; a sum of tricyclic compounds as aromatic and cycloaliphatic of 50-100 wt. %, based on total weight of the decarboxylated rosin acid; and an amount of cycloaliphatic compounds of 15-100 wt. %, based on total weight of the decarboxylated rosin acid. The viscosity improver concentrates comprising the solubilizer have comparable properties, including compatibility, kinematic viscosity, and viscosity index, to other commonly used fossil based solubilizers.

A liquid composition for use in purifying an oil contains a polar polymer, a surface active hydrotrope/solubilizer, and a co-tenside. The polar polymer may be a polyalkylene glycol, such as polyethylene glycol. The hydrotrope/solubilizer may be an anionic sulfonic acid, a phosphate ester-based substance or a non-ionic surfactant from the poly-glycoside family. The co-tenside may be at least one amphoteric co-surfactant, such as sodium caprylimino dipropionate.

The invention relates to an aqueous lubricant composition comprising at least: water; at least one polyalkylene glycol; at least one antifreeze compound selected from glycols, preferably alkylene glycols; glycerol; diglycerol; triglycerol, and mixtures thereof; at least one gallic acid ester; andat least one pH-regulating additive, making it possible to maintain the pH of said lubricant composition between (8) and (15). It also relates to the use of such an aqueous lubricant composition, for lubricating and/or cooling the moving parts in a mechanical system or as a hydraulic fluid. The invention also relates to the use of at least one gallic acid ester as an additive for improving the tribological properties of an aqueous lubricant composition.

The invention relates to an aqueous lubricant composition comprising at least: water; at least one polyalkylene glycol; at least one antifreeze compound selected from glycols, preferably alkylene glycols; glycerol; diglycerol; triglycerol, and mixtures thereof; at least one ascorbic acid ester; and at least one pH-regulating additive, making it possible to maintain the pH of said lubricant composition between (8) and (15). It also relates to the use of such an aqueous lubricant composition, for lubricating and/or cooling the moving parts in a mechanical system or as a hydraulic fluid. The invention also relates to the use of at least one ascorbic acid ester as an additive for improving the tribological properties of an aqueous lubricant composition.

The invention relates to a use of a blend comprising an amphiphilic amine, and an amphiphilic acid for increasing the electric conductivity of a lubricant based on a hydrocarbon oil. The invention further relates to a method for increasing the electric conductivity of a lubricant based on a hydrocarbon oil comprising the step of contacting the hydrocarbon oil with a blend comprising the amphiphilic amine, and the an amphiphilic acid; and to a lubricant based on a hydrocarbon oil comprising a blend comprising the amphiphilic amine which is a compound of formula (A1) and the amphiphilic acid which is selected from compounds (B1), (B3), (B4), (B5), fatty acids, or alkylbenzene sulfonic acids.

A viscosity modifier for lubricating oil, including an (C) ethylene--olefin copolymer having an ethylene molar content rate within a range of 30 to 70 mol %, a rotational viscosity at 150 C. of 300 to 8,000 mPa.Math.s, a Hasen chromaticity of 30 or lower, a molecular weight distribution (Mw/Mn) of 2.5 or less, and a B value of 1.1 or more; a lubricating oil composition with a lubricating oil base oil including a (A) mineral oil having a kinematic viscosity at 40 C. of 10 to 100 mm.sup.2/s, a viscosity index of 90 or more, and a pour point of 0 C. or lower and/or a (B) synthetic oil having a kinematic viscosity at 40 C. of 4 to 100 mm.sup.2/s, a viscosity index of 90 or more and a pour point of 30 C. or lower; and the viscosity modifier having has a kinematic viscosity at 40 C. of 28 to 170 mm.sup.2/s.

The present invention is a lubricating oil composition containing, per 100 parts by mass of (A) an ester compound of a neopentyl polyol having 5 to 10 carbon atoms and a valence of alcohol of 2 to 6 and a linear unsaturated fatty acid having 16 to 22 carbon atoms, 0.1 to 1.5 parts by mass of a specific (B) acid phosphate ester amine salt, 0.01 to 0.25 parts by mass of a specific (C) succinic acid monoester, and 0.01 to 0.25 parts by mass of (D)N-oleoylsarcosine. According to the present invention, it is possible to provide a lubricating oil composition which is excellent in biodegradability, lubricity (anti-wear property), and rust preventive property against seawater, which is low in toxicity and accumulation to aquatic organisms, and further which is excellent in oxidation stability even in the presence of seawater.

A lubricant composition with excellent high-temperature operability, the lubricant composition including: 85 wt % to 95 wt % of a polyalkylene glycol base oil; 1 wt % to 5 wt % of an antioxidant; 1 wt % to 5 wt % of a first anti-wear extreme-pressure additive; and 1 wt % to 5 wt % of a second anti-wear extreme-pressure additive, wherein the antioxidant includes an amine-based compound, the first anti-wear extreme-pressure additive includes an amine salt of phosphate, and the second anti-wear extreme-pressure additive includes a nano-diamond dispersion.

A lubricant composition with excellent high-temperature operability, the lubricant composition including: 85 wt % to 95 wt % of a polyalkylene glycol base oil; 1 wt % to 5 wt % of an antioxidant; 1 wt % to 5 wt % of a first anti-wear extreme-pressure additive; and 1 wt % to 5 wt % of a second anti-wear extreme-pressure additive, wherein the antioxidant includes an amine-based compound, the first anti-wear extreme-pressure additive includes an amine salt of phosphate, and the second anti-wear extreme-pressure additive includes a nano-diamond dispersion.

The present invention provides a magnetic viscous fluid and a mechanical device with both improved drag force during excitation and improved rubber-resistant properties. The magnetic viscous fluid comprises a magnetic particle and base oil, wherein the base oil comprises ester base oil and non-polar base oil, and a non-polarity index of the base oil is in the range of 10 to 45.