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.

The present invention relates to a lubricant composition, in particular for a gas or steam turbine, comprising: at least one base oil; at least one phenylnaphthylamine (PAN) compound, preferably alkylphenyl--naphthylamine (APAN) compound; at least one diphenylamine (DPA) compound, preferably dialkyl-diphenylamine compound; and at least one phosphite ester compound, preferably triaryl phosphite ester compound; in which the ratio by weight between said diphenylamine compound(s) and said phosphite ester compound(s) is strictly greater than 1.0.

A lubricant composition, including 20 to 99.5 wt. %, based on a total weight of the lubricant composition, of a base oil, the base oil having a solubility for ionic liquid methyltrioctylammonium-bis(fluorosulfonyl)imide of at least 3 wt. % at a room temperature of 20 C. The base oil contains a base stock A in a proportion of at least 50 wt. %, based on a total weight of the base oil, the base stock A having a solubility for the ionic liquid methyltrioctylammonium-bis(fluorosulfonyl)imide of at least 3 wt. % at a room temperature of 20 C. The lubricant composition further includes 0.5 to 80% wt. %, based on the total weight of the lubricant composition, of an ionic liquid whose anion is bis(fluorosulfonyl)imide.

A lubricant fluid comprising a base oil, which utilizes carboxylic esters of carboxyl di-end-capped-polyethylene glycols, or a mixture thereof, to have ultra-low viscosity, high flash point, high viscosity index (VI), excellent low temperature properties (viscosity and pour/freeze points), and low elastohydrodynamic (EHD) shear strength, and to enable the production of high efficiency fluids with enhanced temperature properties for machines or machine elements that operate in the elastohydrodynamic regime of lubrication.

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.