Use of a triazole compound as an additive for improving the anti-corrosion properties of a lubricant composition for a propulsion system of an electric or hybrid vehicle

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

adding at least one triazole compound to a lubricant composition for lubricating the propulsion system, the lubricant composition comprising from 0.5% to 2% by mass, relative to the total mass of the lubricant composition, of at least one anti-wear additive chosen from polysulfide additives, amine phosphates, phospho-sulfur additives, sulfur-based olefins, alkylthiophosphates, dimercaptothiadiazole derivatives, 2,5-dimercapto-1,3,4-thiadiazole derivatives, or mixtures of two or more thereof,

wherein the 2,5-dimercapto-1,3,4-thiadiazole derivatives are chosen from compounds having the following formulae:

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, and

wherein the at least one triazole compound is a tolyltriazole derivative represented by the following formula:

wherein:

R 4 and R 5 are independently selected from a hydrogen atom or a branched C 6 to C 12 alkyl group; and

-A- represents a methylene group (—CH 2 —) group.

2. The method of claim 1 , wherein the at least one triazole compound is chosen from optionally substituted triazoles, benzotriazoles and derivatives thereof, or a combination thereof.

3. The method of claim 1 , wherein the at least one triazole compound is chosen from 1,2,3-triazole, a tolyltriazole derivative, or a combination thereof.

4. The method of claim 1 , wherein the tolyltriazole derivative is 2-ethyl-N-(2-ethylhexyl)-N-[(4-methylbenzotriazol-1-yl)methyl]hexan-1-amine.

5. The method of claim 1 , wherein:

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

n is 1.

6. The method of claim 1 , wherein the at least one triazole compound is present in an amount ranging from 0.01% to 5% by mass, relative to the total mass of the lubricant composition.

7. The method of claim 6 , wherein the at least one triazole compound is present in an amount ranging from 0.5% to 2% by mass, relative to the total mass of the lubricant composition.

8. The method of claim 1 , wherein:

the at least one anti-wear additive is a 2,5-dimercapto-1,3,4-thiadiazole derivative; and

the at least one triazole compound is 2-ethyl-N-(2-ethylhexyl)-N-[(4-methylbenzotriazol-1-yl)methyl]hexan-1-amine.

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

an anti-corrosion additive comprising at least one triazole compound; and

from 0.5% to 2% by mass, relative to the total mass of the lubricant composition, of at least one anti-wear additive chosen from polysulfide additives, amine phosphates, phospho-sulfur additives, sulfur-based olefins, alkylthiophosphates, dimercaptothiadiazole derivatives, 2,5-dimercapto-1,3,4-thiadiazole derivatives, or mixtures of two or more thereof,

wherein the 2,5-dimercapto-1,3,4-thiadiazole derivatives are chosen from compounds having the following formulae:

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, and

wherein the at least one triazole compound is a tolyltriazole derivative represented by the following formula:

wherein:

R 4 and R 5 are independently selected from a hydrogen atom or a branched C 6 to C 12 alkyl group; and

-A- represents a methylene group (—CH 2 —) group.

10. The method of claim 9 , wherein:

the at least one triazole compound is 2-ethyl-N-(2-ethylhexyl)-N-[(4-methylbenzotriazol-1-yl)methyl]hexan-1-amine; and

the at least one anti-wear additive is a 2,5-dimercapto-1,3,4-thiadiazole derivative.

11. The method of claim 9 , further comprising lubricating rolling bearings located between a rotor and a stator of the electric motor with the lubricant composition.

12. The method of claim 9 , further comprising lubricating a transmission of the electric or hybrid vehicle with the lubricant composition.