Lubricant composition for preventing corrosion and/or tribo-corrosion of metal parts in an engine

Abstract

Lubricant composition comprising:at least one base oil; and0.1 to 30% by weight of an imidazoline compound of formula (A):defined such that:R1 represents a linear or branched alkyl or alkenyl group comprising 1 to 16 carbon atoms, optionally substituted at the end of the chain by a group selected from among NH2, OH or SH; andR2 represents a linear or branched alkyl or alkenyl group comprising 1 to 36 carbon atoms.

1 . A lubricant composition comprising:
 at least one base oil; and   0.1 to 30% by weight of an imidazoline compound of formula (A):   
       
         
           
           
               
               
           
         
       
       defined such that:
 R 1  represents a linear or branched alkyl group comprising 1 to 16 carbon atoms, optionally substituted at the end of the chain by a group selected from among NH 2  or SH, or R 1  represents a linear or branched alkenyl group comprising 2 to 16 carbon atoms, optionally substituted at the end of the chain by a group selected from among NH 2  or SH; and 
 R 2  represents a linear or branched alkyl group comprising 1 to 36 carbon atoms, or R 2  represents a linear or branched alkenyl group comprising 2 to 36 carbon atoms. 
 
     
     
         2 . The composition according to  claim 1 , further comprising at least one additive selected from among detergents, dispersants and mixtures thereof. 
     
     
         3 . The composition according to  claim 2 , wherein:
 the amount of detergent varies from 3 to 40%; by weight, relative to the total weight of the lubricant composition; and/or   the amount of dispersant varies from 0.01% to 10%, by weight, relative to the total weight of the lubricant composition.   
     
     
         4 . The composition according to  claim 2 , wherein the dispersants are selected from among succinimides. 
     
     
         5 . The composition according  claim 2 , wherein the detergents are calcium carbonate overbased detergents chosen in the group consisting of carboxylates, phenates, sulfonates, salicylates, and mixed phenate-sulfonate-salicylate detergents. 
     
     
         6 . The composition according to  claim 1 , wherein the compound of formula (A) corresponds to the compound of formula (I) defined by the following formula: 
       
         
           
           
               
               
           
         
       
     
     
         7 . Method for preventing and/or reducing corrosion and/or tribocorrosion of at least one metal part of an engine, comprising the addition in a lubricating composition comprising at least one base oil of a compound of formula (A) as defined in  claim 1 . 
     
     
         8 . Method of preventing and/or reducing corrosion and/or tribocorrosion of at least one metal part in an engine, comprising lubricating said metal part with a lubricating composition according to  claim 1 . 
     
     
         9 . The method according to  claim 8  wherein the metal part is a cylinder. 
     
     
         10 . A method for passivating at least one metal part of an engine, comprising at least one step to place said metal part in contact with a lubricant composition defined according to  claim 1 .