USE OF A PHOSPHORUS COMPOUND AS A NON-CORROSIVE EXTREME-PRESSURE AND ANTI-WEAR ADDITIVE IN A LUBRICANT FOR A PROPULSION SYSTEM OF AN ELECTRIC OR HYBRID VEHICLE

1 - 10 . (canceled)

11 . A method of improving the anti-wear properties of a lubricant composition for a propulsion system of an electric or hybrid vehicle, comprising:

adding at least one phosphorus compound to a lubricant composition for lubricating the propulsion system,

wherein the at least one phosphorous compound is free of sulfur and amine functional groups.

12 . The method of claim 11 , wherein the at least one phosphorus compound is selected from phosphate esters, phosphonate esters, phosphinate esters, phosphite esters, phosphine oxides, or a combination thereof.

13 . The method of claim 11 , wherein the at least one phosphorus compound is selected from compounds of formula (I) below:

wherein:

s is 0 or 1; and

each X group is independently selected from —OR′ or R′ groups, wherein R′ represents a hydrocarbon group having from 1 to 24 carbon atoms;

when s is 0, each X group is an —OR′ group; and

when s is 1, at least two of the X groups are —OR′ groups.

14 . The method of claim 11 , wherein the at least one phosphorus compound is selected from phosphate esters of formula (II) below:

wherein:

each R group is independently selected from linear or branched, C 1 to C 10 alkyl groups; and

each n is independently selected from 0, 1 or 2.

15 . The method of claim 14 , wherein:

each n is 1; and

each R group is a branched C 3 to C 6 alkyl group in a para position.

16 . The method of claim 11 , wherein the at least one phosphorus compound is tri(isopropylphenyl) phosphate.

17 . The method of claim 11 , wherein the at least one phosphorus compound is selected from phosphite esters of formula (II′) below:

wherein:

each R group is independently selected from linear or branched, C 1 to C 10 alkyl groups; and

each n is independently selected from 0, 1 or 2.

18 . The method of claim 17 , wherein:

each n is 1; and

each R group is a branched C 3 to C 6 alkyl group in a para position.

19 . The method of claim 11 , wherein the at least one phosphorus compound is tris(2,4-di-tert-butylphenyl) phosphite.

20 . The method of claim 11 , wherein the lubricant composition comprises from 0.01% and 10% by mass of the at least one phosphorus compound, relative to the total mass of the lubricant composition.

21 . The method of claim 11 , wherein the lubricant composition comprises from 0.5% and 3% by mass of the at least one phosphorus compound, relative to the total mass of the lubricant composition.

22 . The method of claim 11 , wherein the lubricating composition comprises at least one base oil selected from polyalkylene glycols, polyalphaolefins, esters of carboxylic acids, alcohols, or a combination thereof.

23 . A method of reducing wear in in a propulsion system of an electric or hybrid vehicle, the method comprising lubricating and/or cooling an electric motor and/or power electronics of the electric or hybrid vehicle with a lubricant composition comprising at least one phosphorus compound that is free from sulfur and amine functional groups.

24 . The method of claim 23 , wherein the at least one phosphorus compound comprises tri(isopropylphenyl) phosphate, tris(2,4-di-tert-butylphenyl) phosphite, or a combination thereof.

25 . The method of claim 23 , further comprising lubricating rolling bearings located between a rotor and a stator of the electric motor with the lubricant composition.

26 . The method of claim 23 , further comprising lubricating a reduction gear of a transmission of the electric or hybrid vehicle with the lubricant composition.

27 . The method of claim 23 , wherein the lubricating composition comprises, relative to the total mass of the lubricating composition:

from 0.1% to 5% by mass of the at least one phosphorus compound;

from 50% to 99.5% by mass of at least one base oil selected from group III base oils, group IV base oils, group V base oils, or a combination thereof; and

optionally from 0.1 to 5% by mass of at least one additive selected from antioxidants, detergents, dispersants, pourpoint depressants, antifoam agents, or a combination thereof.

28 . The method of claim 27 , wherein:

the lubricating composition comprises from 0.5 to 3% by mass of the at least one phosphorus compound;

the at least one phosphorus compound is selected from tri(isopropylphenyl) phosphate, tris(2,4-di-tert-butylphenyl) phosphite, or a combination thereof; and

the lubricating composition comprises from 60 to 99% by mass of the at least one base oil.