USE OF A SUCCINIMIDE COMPOUND AS AN ANTI-CORROSION ADDITIVE IN A LUBRICANT COMPOSITION FOR A PROPULSION SYSTEM OF AN ELECTRIC OR HYBRID VEHICLE

1 - 10 . (canceled)

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

adding at least one succinimide compound to a lubricant composition for lubricating the propulsion system, the lubricant composition comprising an amine-based anti-wear additive and/or a sulfur-based anti-wear additive.

12 . The method of claim 11 , wherein the at least one succinimide compound is chosen from polyalkylene mono- or bis-succinimides; borate derivatives of polyalkylene mono- or bis-succinimides; succinic anhydride derivatives of polyalkylene mono- or bis-succinim ides; compounds obtained by opening such a succinic anhydride ring; or a combination thereof.

13 . The method of claim 11 , wherein the at least one succinimide compound is chosen from: polyisobutene (PIB) mono- or bis-succinim ides; borate derivatives of polyisobutene (PIB) mono- or bis-succinimides; polyisobutylene succinic anhydrides (PIBSA); polyisobutylene pentaerythritol ester succinimides; or a combination thereof.

14 . The method of claim 11 , wherein the at least one succinimide compound comprises at least one substituted succinimide group of formula (ii) below:

borate derivatives of formula (ii),

succinic anhydride derivatives of formula (ii), or

a compound obtained by opening of the succinic anhydride ring of formula (ii),

wherein R 1 represents a hydrocarbon-based group comprising from 8 to 400 carbon atoms.

15 . The method of claim 14 , wherein R 1 represents a polyalkene group optionally linked to the succinimide group via a —(C═CH 2 )—group and having a mass-average molecular mass Mw of between 2000 and 30,000.

16 . The method of claim 14 , wherein R 1 represents a polyisobutylene group optionally linked to the succinimide group via a —(C═CH 2 )—group and having a mass-average molecular mass Mw of between 2000 and 7000.

17 . The method of claim 11 , wherein the at least one succinimide compound is a mono-succinimide of formula (II) below:

or a borate derivative thereof,

wherein:

R 1 represents a polyalkylene group optionally linked to the succinimide group via a —(C═CH 2 )—group;

A represents a linear or branched C 2 to C 6 alkylene group; and

y represents an integer ranging from 2 to 5.

18 . The method of claim 17 , wherein:

R 1 represents a polyisobutylene group optionally linked to the succinimide group via a —(C═CH 2 )—group;

A represents at least one of the following segments: —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —, —CH 2 —CH(CH 3 )—; and

y represents 2, 3, or 4.

19 . The method of claim 11 , wherein the at least one succinimide compound is a bis-succinimide of formula (III) below:

or a borate derivative thereof,

wherein:

R 1 represents polyalkylene groups optionally linked to the succinimide group via a —(C═CH 2 )—group;

z represents an integer ranging from 1 to 10; and

s represents an integer ranging from 2 to 6.

20 . The method of claim 19 , wherein:

R 1 represents polyisobutylene groups optionally linked to the succinimide group via a —(C═CH 2 )—group;

z represents an integer ranging from 2 to 6; and

s represents an integer ranging from 2 to 4.

21 . The method of claim 11 , wherein the amine-based anti-wear additive and/or the sulfur-based anti-wear additive is chosen from 2,5-dimercapto-1,3,4-thiadiazole derivatives having the following formulae, taken alone or as a mixture:

wherein:

each R 1 group is independently selected from a hydrogen atom, a linear or branched alkyl or alkenyl group comprising from 2 to 18 carbon atoms, or an aromatic substituent; and

each n is independently selected from 1, 2, 3, or 4.

22 . The method of claim 21 , wherein:

each R 1 group is independently selected from a hydrogen atom or linear or branched alkyl or alkenyl groups comprising from 8 to 12 carbon atoms or aromatic substituents; and

n is 1.

23 . The method of claim 11 , wherein:

the at least one succinimide compound is present in an amount ranging from 0.1% to 10% by mass, relative to the total mass of the lubricant composition; and

the amine-based anti-wear additive and/or the sulfur-based anti-wear additive is present in an amount ranging from 0.01% to 10% by mass, relative to the total mass of the lubricant composition.

24 . The method of claim 23 , wherein:

the at least one succinimide compound is present in an amount ranging from 0.5% to 8% by mass, relative to the total mass of the lubricant composition; and

the amine-based anti-wear additive and/or the sulfur-based anti-wear additive is present in an amount ranging from 0.5% to 3% by mass, relative to the total mass of the lubricant composition.

25 . A method of reducing corrosion in a propulsion system of an electric or hybrid vehicle, the method comprising lubricating an electric motor and/or power electronics of the electric or hybrid vehicle with a lubricant composition comprising:

at least one succinimide compound; and

an amine-based anti-wear additive and/or a sulfur-based anti-wear additive.

26 . The method of claim 25 , wherein:

at least one succinimide compound is chosen from: polyisobutene (PIB) mono- or bis-succinimides; borate derivatives of polyisobutene (PIB) mono- or bis-succinimides; polyisobutylene succinic anhydrides (PIBSA); polyisobutylene pentaerythritol ester succinim ides; or a combination thereof; and

the amine-based anti-wear additive and/or the sulfur-based anti-wear additive is a 2,5-dimercapto-1,3,4-thiadiazole derivative.

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

28 . The method of claim 25 , further comprising lubricating a transmission of the electric or hybrid vehicle with the lubricant composition.