Synthetic Lubricating Oil

Abstract

The object of the present invention is to provide a synthetic lubrication oil which shows low viscosity, is excellent in viscosity properties at high temperature and shows stable lubricating properties in a wide range of temperature. The synthetic lubricating oil is one comprising an ionic liquid containing an organic cation selected from the group consisting of an imidazolium cation, a pyridinium cation, a quaternary ammonium cation and a quaternary phosphonium cation and a bis(fluorosulfonyl)imide anion, and one comprising an ionic liquid composition which comprises an ionic liquid (A) containing a 1-ethyl-3-methylimidazolium cation and an ionic liquid (B1) containing a 1-methyl-3-propylimidazolium cation and/or an ionic liquid (B2) containing a 1-methyl-3-isopropylimidazolium cation.

1 . A synthetic lubricating oil comprising an ionic liquid containing an organic cation selected from the group consisting of an imidazolium cation, a pyridinium cation, a quaternary ammonium cation and a quaternary phosphonium cation and a bis(fluorosulfonyl)imide anion. 
   
   
       2 . The synthetic lubricating oil of  claim 1 , wherein the organic cation is an imidazolium cation. 
   
   
       3 . The synthetic lubricating oil of  claim 2 , wherein the imidazolium cation is a 1,3-disubstituted imidazolium cation in which the substituents on the position-1 and the position-3 may be same or different, or a 1,2,3-trisubstituted imidazolium cation in which the substituents on the position-1, the position-2 and the position-3 may be same or different. 
   
   
       4 . A synthetic lubricating oil comprising an ionic liquid composition comprising an ionic liquid (A) containing a 1-ethyl-3-methylimidazolium cation and an ionic liquid (B1) containing a 1-methyl-3-propylimidazolium cation and/or an ionic liquid (B2) containing a 1-methyl-3-isopropylimidazolium cation. 
   
   
       5 . The synthetic lubricating oil of  claim 4 , wherein an anion part of the ionic liquid (A) and an anion part of the ionic liquid (B1) and/or the ionic liquid (B2) are same. 
   
   
       6 . The synthetic lubricating oil of  claim 5 , wherein the anion parts of the ionic liquid (A) and the ionic liquid (B1) and/or the ionic liquid (B2) are bis(fluorosulfonyl)imide or (fluorosulfonyl)(trifluoromethanesulfonyl)imide. 
   
   
       7 . The synthetic lubricating oil of  claim 6 , wherein a mixing ratio (weight ratio) of the ionic liquid (A) to the ionic liquid (B1) and/or the ionic liquid (B2) is (A):(B1) and/or (B2)=8:2 to 2:8. 
   
   
       8 . The synthetic lubricating oil of  claim 4 , wherein the anion parts of the ionic liquid (A) and the ionic liquid (B1) and/or the ionic liquid (B2) are bis(fluorosulfonyl)imide or (fluorosulfonyl)(trifluoromethanesulfonyl)imide. 
   
   
       9 . The synthetic lubricating oil of  claim 4 , wherein a mixing ratio (weight ratio) of the ionic liquid (A) to the ionic liquid (B1) and/or the ionic liquid (B2) is (A):(B1) and/or (B2)=8:2 to 2:8. 
   
   
       10 . The synthetic lubricating oil of  claim 5 , wherein a mixing ratio (weight ratio) of the ionic liquid (A) to the ionic liquid (B1) and/or the ionic liquid (B2) is (A):(B1) and/or (B2)=8:2 to 2:8.