Synthetic lubricant

Abstract

Provided is a lubricating oil additive which is able to impart friction adjusting performance and rust preventing performance which are essential for practical use of a lubricant composed of an ionic liquid, and is dissolved or dispersed in the ionic liquid even when blended with the ionic liquid, and thus, does not inhibit performances as a base oil of the ionic liquid. The present invention relates to a synthetic lubricant including a fluorine atom-containing ionic liquid (A) as a main component, wherein the synthetic lubricant contains an imidazolium phosphate ester salt (B).

1 . A synthetic lubricant including a fluorine atom-containing ionic liquid (A) as a main component, wherein the synthetic lubricant contains an imidazolium phosphate ester salt (B). 
     
     
         2 . The synthetic lubricant according to  claim 1 , wherein a cation moiety of the fluorine atom-containing ionic liquid (A) is an imidazolium cation. 
     
     
         3 . The synthetic lubricant according to  claim 1 , wherein an anion moiety of the fluorine atom-containing ionic liquid (A) is a fluorine-containing imide anion represented by the following formula (1):
   (C n F 2n+1 SO 2 ) 2 N −   (1)
   wherein n is an integer of 0 to 15.   
     
     
         4 . The synthetic lubricant according to  claim 1 , wherein the anion moiety of the fluorine atom-containing ionic liquid (A) is bis(fluorosulfonyl)imide or bis(trifluoromethanesulfonyl)imide. 
     
     
         5 . The synthetic lubricant according to  claim 1 , wherein the imidazolium cation of the imidazolium phosphate ester salt (B) is a 1,3-disubstituted imidazolium cation. 
     
     
         6 . The synthetic lubricant according to  claim 1 , wherein the phosphate ester anion of the imidazolium phosphate ester salt (B) is a phosphate ester anion having a diester structure. 
     
     
         7 . The synthetic lubricant according to  claim 1 , wherein the imidazolium phosphate ester salt (B) is a compound represented by the following formula (2): 
       
         
           
           
               
               
           
         
         wherein each of R1 and R2 is independently an alkyl group having 1 to 16 carbon atoms, and R3 is an alkyl group having 1 to 8 carbon atoms.