Polyalkylene glycol-based lubricant composition

Abstract

Disclosed is a lubricant composition including: an oil chosen from polyalkyl glycols (PAG or polyalkylene glycols); and an anti-wear additive chosen from compounds of formula (I) in which R1 and R2, which may be identical or different, independently represent a linear or branched secondary alkyl group including from 2 to 7 carbon atoms, preferably from 3 to carbon atoms. This lubricant composition is particularly useful for the lubrication of a vehicle engine, preferably of a motor vehicle.

1 - 14 . (canceled) 
     
     
         15 . Composition comprising 1 to 99.5% by weight of an oil selected from polyalkyl glycols (PAG or polyalkylene glycols) and an anti-wear additive selected from the compounds of formula (I) 
       
         
           
           
               
               
           
         
       
       in which R1 and R2, which may be identical or different, independently represent a linear or branched secondary alkyl group comprising from 2 to 7 carbon atoms. 
     
     
         16 . Composition according to  claim 15  wherein the PAG is a block polymer of formula (II) or a random polymer of formula (II) 
       
         
           
           
               
               
           
         
       
       in which:
 R3 represents a linear or branched C 1 -C 30 -alkyl group; 
 n represents a number ranging from 2 to 60; 
 R4 and R5, identical or different, independently represent a hydrogen atom or a C 1 -C 2 -alkyl group. 
 
     
     
         17 . Composition according  claim 15  for which the PAG is chosen from
 a block polymer of formula (IIA) or a random polymer of formula (IIA) 
 
       
         
           
           
               
               
           
         
       
       in which:
 R3 represents a linear or branched C 1 -C 30 -alkyl group; 
 m represents a number ranging from 2 to 60; 
 R6 and R7 represent a hydrogen atom; or R6 represents a hydrogen atom and R7 represents a methyl group; or R6 represents a methyl group and R7 represents a hydrogen atom; or R6 and R7 represent a methyl group; or R6 represents an ethyl group and R7 represents a hydrogen atom; or R6 represents a hydrogen atom and R7 represents an ethyl group; 
 a block polymer of formula (IIB) or a random polymer of formula (IIB) 
 
       
         
           
           
               
               
           
         
       
       in which:
 R3 represents a linear or branched C 1 -C 30 -alkyl group; 
 p and q independently represent a number ranging from 1 to 30; 
 R8 and R9 represent a hydrogen atom; or R8 represents a hydrogen atom and R9 represents a methyl group; or R8 represents a methyl group and R9 represents a hydrogen atom; or R8 and R9 represent a methyl group; or R8 represents an ethyl group and R9 represents a hydrogen atom; or R8 represents a hydrogen atom and R9 represents an ethyl group; 
 R10 and R11 represent a hydrogen atom; or R10 represents a hydrogen atom and R11 represents a methyl group; or R10 represents a methyl group and R11 represents a hydrogen atom; or R10 and R11 represent a methyl group; or R10 represents an ethyl group and R11 represents a hydrogen atom; or R10 represents a hydrogen atom and R11 represents an ethyl group. 
 
     
     
         18 . Composition according to  claim 15  for which the PAG is chosen from
 a block polymer of formula (III) or a random polymer of formula (III) 
 
       
         
           
           
               
               
           
         
       
       in which:
 R3 represents a linear or branched C 4 -C 12 -alkyl group; 
 p represents a number ranging from 1 to 30; 
 q represents a number ranging from 1 to 30, or a block polymer of formula (IV) or a random polymer of formula (IV) 
 
       
         
           
           
               
               
           
         
       
       in which:
 R3 represents a linear or branched C 8 -C 12 -alkyl group; 
 p represents a number ranging from 2 to 6; 
 q represents a number ranging from 2 to 5. 
 a block polymer of formula (V) or a random polymer of formula (V) 
 
       
         
           
           
               
               
           
         
       
       in which:
 R3 represents a linear or branched C 4 -C 12 -alkyl group; 
 r represents a number ranging from 2 to 60. 
 
     
     
         19 . Composition according to  claim 15  wherein the PAG is a block polymer of formula (VI) or a random polymer of formula (VI) 
       
         
           
           
               
               
           
         
       
       in which:
 R12 represents a linear or branched C 1 -C 30 -alkyl group; 
 s and t independently represent an average number ranging from 1 to 5. 
 
     
     
         20 . Composition according to  claim 15  comprising 1 to 99.5% by weight of PAG. 
     
     
         21 . Composition according to  claim 15  comprising from 1 to 30% by weight of PAG. 
     
     
         22 . Composition according to  claim 15  comprising from 40 to 99.5% by weight of PAG. 
     
     
         23 . Composition according to  claim 15  comprising from 5 to 80% by weight of PAG. 
     
     
         24 . Composition according to  claim 15  wherein the anti-wear additive is selected from compounds of formula (I) 
       
         
           
           
               
               
           
         
       
       in which R1 and R2, identical or different, represent a secondary C3-alkyl group or a secondary C6-alkyl group. 
     
     
         25 . Composition according to  claim 15  comprising from 0.1 to 3% by weight of compound of formula (I). 
     
     
         26 . Composition according to  claim 15  comprising a lubricating base oil. 
     
     
         27 . Composition according to  claim 15 , further comprising an organic friction modifier selected from esters. 
     
     
         28 . Method of lubricating a motor vehicle, preferably a motor vehicle, comprising at least one step of bringing the motor into contact with the lubricating composition according to  claim 15 .