Use of a sterically hindered aromatic amine or phenol compound as an anti-corrosion additive in a lubricant composition for a propulsion system of an electric or hybrid vehicle

Abstract

The invention relates to the use of at least one compound, which has at least one sterically hindered amine or phenolic function, as an anti-corrosion additive in a lubricant composition for a propulsion system of an electric or hybrid vehicle, said lubricant composition comprising one or more amino and/or sulfur anti-wear additives. The invention also relates to the use of a lubricant composition comprising one or more compounds, which has at least one sterically hindered amine or phenolic function, as one or more anti-corrosion additives, further comprising one or more amino and/or sulfur anti-wear additives, for lubricating a propulsion system of an electric or hybrid vehicle, in particular for lubricating the electric motor and the power electronics of an electric or hybrid vehicle.

1 - 10 . (canceled) 
     
     
         11 . A method for improving the anti-corrosion properties of a lubricant composition of a propulsion system of an electric or hybrid vehicle, comprising:
 adding at least one anti-corrosion compound bearing at least one sterically hindered amine or phenol functional group 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 anti-corrosion compound is chosen from sterically hindered aromatic amines, sterically hindered phenols, or a combination thereof. 
     
     
         13 . The method of  claim 11 , wherein the at least one anti-corrosion compound is chosen from sterically hindered diarylamine compounds, sterically hindered alkylphenols, or a combination thereof. 
     
     
         14 . The method of  claim 11 , wherein the at least one anti-corrosion compound is chosen from diarylamine compounds having the following formula:
   R 6 —NH—R 7 ,
   wherein R 6  and R 7  are independently chosen from:   a phenyl group that is optionally substituted para to the amine function with hydrocarbon-based groups chosen from alkyl or alkenyl groups comprising from 1 to 12 carbon atoms; and   a naphthyl group that is optionally substituted para to the amine function with alkyl or alkenyl groups comprising from 1 to 12 carbon atoms.   
     
     
         15 . The method of  claim 11 , wherein the at least one anti-corrosion compound is chosen from diarylamine compounds having the following formula (I): 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently chosen from a hydrogen atom, linear or branched alkyl or alkenyl groups comprising from 1 to 12 carbon atoms. 
       
     
     
         16 . The method of  claim 11 , wherein the at least one anti-corrosion compound is chosen from diarylamine compounds having the following formula (I′): 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently chosen from linear or branched C 1  to C 12  alkyl groups. 
       
     
     
         17 . The method of  claim 16 , wherein R 1  and R 2  are independently chosen from linear or branched octyl or butyl groups. 
     
     
         18 . The method of  claim 11 , wherein the at least one anti-corrosion compound is chosen from sterically hindered phenols having the formula (II′): 
       
         
           
           
               
               
           
         
         wherein: 
         R 1  and R 2  are independently chosen from a C 1 -C 10  alkyl group or a hydroxyl group, with at least one of R 1  and R 2  representing C 1 -C 10  alkyl group; 
         n is 1 or 2; 
         each R group is independently chosen from a hydroxyl group or C 1 -C 10  alkyl groups that are optionally substituted with one or more C 2  to C 10  alkoxycarbonyl groups and/or with one or more aryl groups that are optionally substituted with one or more alkyl groups. 
       
     
     
         19 . The method of  claim 18 , wherein at least one of R 1  and R 2  represents a C 4  alkyl group. 
     
     
         20 . The method of  claim 11 , wherein the at least one anti-corrosion compound is chosen from p,p′-butyloctyldiphenylamine, octyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, 2,6-di-tert-butylphenol, or a combination thereof. 
     
     
         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 in combination: 
       
         
           
           
               
               
           
         
         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, 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, relative to the total mass of the lubricant composition:
 the at least one anti-corrosion compound is present in an amount ranging from 0.01% to 5% by mass; and/or   the amine-based and/or sulfur-based anti-wear additive is present in an amount ranging from 0.01% to 5% by mass.   
     
     
         24 . The method of  claim 23 , wherein, relative to the total mass of the lubricant composition:
 the at least one anti-corrosion compound is present in an amount ranging from 0.1% to 1% by mass; and/or   the amine-based anti-wear additive and/or the sulfur-based anti-wear additive is present in a content ranging from 0.1% to 1% by mass.   
     
     
         25 . 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:
 at least one anti-corrosion compound bearing at least one sterically hindered amine or phenol functional group; and   an amine-based anti-wear additive and/or a sulfur-based anti-wear additive.   
     
     
         26 . The method of  claim 25 , wherein:
 the at least one anti-corrosion compound is chosen from sterically hindered diphenylamine compounds, sterically hindered alkylphenol compounds, 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.