SYNTHETIC LUBRICANT
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.