Lubricating compositions

A lubricating composition wherein the ionic liquid is a salt of general formula C+A− wherein the cation C+ is selected from a quaternary ammonium cation, a phosphonium cation, an imidazolium cation, a pyridinium cation, a pyrazolium cation, an oxazolium cation, a pyrrolidinium cation, a piperidinium cation, a trialkylsulfonium cation, a thiazolium cation, a guanidinium cation, a morpholinium cation, a sulfonium cation and a triazolium cation and wherein the anion A−is selected from [PF6]−, [CF3CO2]−, [CF3SO3]−, as well as its higher homologues, [C4F9SO3]− or [C8F17SO3]− and higher perfluoroalkylsulfonates, [(CF3SO2)2N], [(CF3SO2)(CF3COO)N]−, Cl−, Br−, I−, [C(CN)3]−, SCN−, [B(C2O4)2]−, [N(SO2CF3)2]−, [R4SO3]−, [R4OSO3]−, [R4COO]−, [NO3]−, [N(CN)2]−, [HSO4]−, PF6-xR6x or [R4R5PO4]−, wherein R4 and R5 are independently selected from hydrogen, linear or branched, saturated or unsaturated, aliphatic or alicyclic alkyl groups with 1 to 20 carbon atoms;

• heteroaryl, heteroaryl-C1-C6-alkyl groups with 3 to 8 carbon atoms in the hetero aryl residue and at least one heteroatom selected from N, O and S, which can be substituted with at least one group selected from C1-C6 alkyl groups and/or halogen atoms;
• aryl-aryl-C1-C6-alkyl groups with 5 to 12 carbon atoms in the aryl residue, which can be substituted with at least one C1-C6-alkyl group, R6 can be a perfluoroethyl or a higher perfluoroalkyl group, and x is an integer of from 1 to 4.