The present application concerns the use, for cooling and/or lubricating a propulsion system of an electric or hybrid vehicle, of an aqueous lubricating composition comprising at least: water and a polyalkylene glycol; the said aqueous lubricating composition comprising a phosphate ester salt(s) content of strictly less than 0.1% by mass, relative to the total mass of the said composition.

It also relates to the use of such an aqueous lubricant composition to reduce pitting by mechanical fatigue of the mechanical part(s) of an electric or hybrid vehicle propulsion system which is (are) brought into contact with the said composition.

Lastly, it relates to an aqueous lubricating composition for lubricating and/or cooling an electric or hybrid propulsion system, comprising: at least 45% by mass of water, relative to the total mass of the composition, and a polyalkylene glycol; the said composition comprising a phosphate ester salt(s) content of strictly less than 0.1% by mass, relative to the total mass of the said composition.

The present invention relates a lubricant comprising a base stock selected from hydrocarbons, 50 to 1000 ppm water, and an alkoxylated alcohol, where the alcohol is alkoxylated with a hydrophobic epoxide selected from C.sub.4-C.sub.20 epoxides. The invention also relates to a method for lubricating a mechanical device in an electric vehicle comprising the step of contacting the lubricant with the mechanical device; to a use of the alkoxylated alcohol for increasing the breakdown voltage of a lubricant comprising the basestock selected from the hydrocarbons; and to a use of the alkoxylated alcohol in a lubricant comprising the base stock selected from the hydrocarbons for reducing the electric discharge machining.

There has been a need for a novel lubricating oil composition which has characteristics (for example, scuffing resistance and copper corrosion resistance) that are suitable for lubrication of various mechanisms that are incorporated in a device. The present invention provides a lubricating oil composition which contains (A) a base oil and (B) a phosphite ester that has at least one sulfur atom-containing group having 2 to 20 carbon atoms, the group having at least one (S) x- group (wherein x is an integer of 1 or more) between two adjacent carbon atoms in the structure of an alkyl group, wherein: the content of a thiadiazole compound is less than 0.05% by mass based on the total amount of the lubricating oil composition; and the kinematic viscosity of the lubricating oil composition at 100 C. is 4.2 mm.sup.2/s or more.

A lubricating oil composition including: (A) a lubricant base oil; (B1) a first amide compound, and/or a salt thereof, the first amide compound being a monoamide of a fatty acid (a1), and an amine compound (a2), the compound (a2) being an oligomer of an alkanolamine (a3) of the general formula (1); and (B2) a second amide compound having a structure such that an amino group and at least one hydroxy group of the alkanolamine (a3) are acylated with the fatty acid (a1), wherein the inequation (eq1) is satisfied:

[00001]$\begin{array}{cc}{M}_{B2}0.50M_{B1}& \left(\mathrm{eq}1\right)\end{array}$

in the inequation, M.sub.B1 and M.sub.B2 are a content of the first amide compound, and a content of the (B2) component (mass %), respectively,

##STR00001##

in the formula, n is 1 or 2; R.sup.1 is C1-4 linear chain alkylene or C3-10 branched chain alkylene having a C2 main chain; and a plurality of R.sup.1's may be same, and may be different from each other.

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.

There has been a demand for a lubricating oil composition that has excellent cooling performance and insulating properties. This lubricating oil composition contains a base oil (A), solid particles (B) that have an average primary particle diameter of 500 nm or less, and a dispersant (C); the content of the solid particles (B) is 0.1 to 30% by mass based on the total amount of the lubricating oil composition; and the content of the dispersant (C) is 0.1 to 20% by mass based on the total amount of the lubricating oil composition.

A low-viscosity lubricating oil composition with improved durability and NVH (noise, vibration, and harshness) performance is provided. The durability and NVH performance of the low-viscosity lubricating oil can be improved by appropriately combining mineral oil and/or synthetic oil and a viscosity index improver.

The present invention relates to the use of a composition comprising 1-methylheptyl laurate as a lubricant composition for transmissions.

A lubricating oil additive composition including: (i) at least one first amide compound, and/or a salt thereof, the at least one first amide compound being a monoamide of at least one fatty acid (a1), and at least one amine compound (a2), the amine compound (a2) being an oligomer of at least one alkanolamine (a3) represented by the general formula (1); and (ii) at least one second amide compound having a structure such that an amino group and at least one hydroxy group of the alkanolamine (a3) are acylated with the fatty acid (a1): ##STR00001##
in the formula, n is 1 or 2; R.sup.1 is C1-4 linear chain alkylene or C3-10 branched chain alkylene having a main chain, the main chain having a carbon number of 2; and when n is 2, a plurality of R.sup.1's may be the same, and may be different from each other.