The present invention relates to additives for reducing friction and wear in lubricants. In particular, the present invention relates to novel salts and their use in lubricating oil compositions for reducing friction and wear. In particular, the present invention relates to one or more ionic liquids, wherein the one or more ionic liquids comprise one or more cations and one or more Group 6 metal mononuclear metallate anions.

A lubricating agent including an ionic liquid formed from a Bronsted acid (HX) and a Bronsted base (B), wherein the Bronsted base has a linear hydrocarbon group having 10 or more carbon atoms and the difference between the pKa value of the Bronsted acid in water and the pKa value of the Bronsted base in water is 12 or more.

A lubricant, which includes an ionic liquid including a conjugate base and a conjugate acid, wherein the conjugate acid has a group including a straight-chain hydrocarbon group having 6 or more carbon atoms, a pKa of an acid that is a source of the conjugate base in acetonitrile is 10 or less, and solubility of the ionic liquid to CF.sub.3(CHF).sub.2CF.sub.2CF.sub.3 is 0.1 parts by mass relative to 100 parts by mass of CF.sub.3(CHF).sub.2CF.sub.2CF.sub.3.

A lubricating agent including an ionic liquid formed from a Bronsted acid (HX) and a Bronsted base (B), wherein the Bronsted base has a linear hydrocarbon group having 10 or more carbon atoms and the difference between the pKa value of the Bronsted acid in water and the pKa value of the Bronsted base in water is 12 or more.

A low transition temperature mixture (LTTM) or deep eutectic solvent (DES) useful as a lubricating oil base stock and lubricating oil including a eutectic mixture of at least a first component and at least a second component. The at least first component comprises a hydrogen bond acceptor and the at least second component comprises a hydrogen bond donor. The eutectic mixture includes an equilibrium phase between the at least first component and the at least second component. The equilibrium phase does not exhibit physical characteristics of the at least first component in an unmixed state and the at least second component in an unmixed state. The at least first component and the at least second component form an intermolecular interaction between each other sufficient to prevent crystallization of the at least first component and the at least second component in the eutectic mixture. The eutectic mixture is a liquid at 20 C.

A lubricant which includes an ionic liquid including a conjugate acid and a conjugate base having 2 or more anions in a molecule of the conjugate base, wherein the conjugate acid has a group including a straight-chain hydrocarbon group having 6 or more carbon atoms, and a pKa of an acid that is a source of the conjugate base in acetonitrile is 10 or less.

The invention is directed to a zinc-free lubricating composition for an internal combustion engine containing a phosphorus anti-wear agent, an ashless antioxidant, and a metal-free basic detergent. The lubricating composition provides wear protection, deposit control, and improved acid control with reduced levels of metal-containing additives.

A method to reduce and/or eliminate and/or delay the corrosion in the internal parts of a combustion engine, includes at least a step of application to said engine of an ammonium-based ionic liquid compound of formula (I)

[CAT.sup.+] [X.sup.](I)

wherein [CAT.sup.+] is tri-n-octylmethylammonium and [X.sup.] is selected from compounds of formula (IA):

##STR00001##

wherein R is selected from linear or branched alkyl and alkenyl groups comprising from 2 to 8 atoms of carbon.

A guanidinium-based ionic liquid compound including a 1,1,3,3-tetramethylguanidinium cation and an alcoholate anion. A lubricant composition including it, and its use as a detergent and as anti-corrosion additive in a lubricant composition, in particular a marine lubricant.

Provided is a lubricant including a silicon-containing ionic liquid represented by formula (1).

##STR00001##

(In the formula, R.sup.1 represents an alkyl group having 1 to 10 carbon atoms, R.sup.2 represents an alkyl group having 8 to 20 carbon atoms, and R.sup.3 represents an alkyl group having 1 to 8 carbon atoms. Herein, it is provided that the number of carbon atoms in R.sup.2 is greater than the number of carbon atoms in R.sup.1.)