Ashless or reduced ash quaternary detergents
A composition of an oil-soluble ionic detergent that does not contribute metal ions to the composition, and which comprises a quaternary non-metallic pnictogen cation and an organic anion having at least one hydrocarbyl group of sufficient length to impart oil solubility to the detergent, the detergent having a total base number (TBN) to total acid number (TAN) ratio of at least 2:1 imparts ash-free basicity to a lubricant composition.
1. A composition comprising an oil-soluble ionic detergent, which detergent comprises
(a) a quaternary ammonium cation and
(b) an organic anion having at least one aliphatic hydrocarbyl group of sufficient length to impart oil solubility to the detergent;
said oil-soluble ionic detergent having a total base number (TBN) to total acid number (TAN) ratio of at least about 2:1;
wherein said oil-soluble ionic detergent exhibits a TBN of at least about 10 arising from a non-metallic base, and wherein said oil-soluble ionic detergent comprises a stoichiometric excess of quaternary ammonium cations of (a) over organic anions of (b) such that said cations and anions are present in an equivalent ratio (a):(b) of at least about 2:1;
and wherein the overbased detergent further comprises an oxo-anion which comprises a carbonate, bicarbonate, borate, hydroxide, nitrate, phosphate, sulfate, or carboxylate ion or mixtures thereof, said carboxylate ion containing 5 or fewer carbon atoms.
2. The composition of claim 1 wherein the cation comprises a tetrahydrocarbyl ammonium ion.
3. The composition of claim 1 wherein the cation comprises four groups selected from the group consisting of methyl groups, ethyl groups, propyl groups, butyl groups, benzyl groups, phenyl groups, hydroxyalkyl groups, aminoalkyl groups, and mixtures thereof.
4. The composition of claim 1 wherein the cation comprises a pyridinim ion or an imidazolium ion.
5. The composition of claim 1 wherein the oil-soluble ionic detergent comprises a sulfonate, carboxylate, salicylate, or phenate anion.
6. The composition of claim 1 wherein the oil-soluble ionic detergent has a TBN of about 50 to about 300 and a TAN of less than about 10.
7. The composition of claim 1 wherein the oil-soluble detergent has a TBN:TAN ratio of about 7:1 to about 150:1.
8. The composition of claim 1 wherein the oil-soluble ionic detergent does not contribute metal ions to the composition.
9. A composition comprising an oil-soluble ionic detergent, which detergent comprises
(a) a quaternary ammonium cation wherein the cation comprises a pyridinim ion or an imidazolium ion, and
(b) an organic anion having at least one aliphatic hydrocarbyl group of sufficient length to impart oil solubility to the detergent;
said oil-soluble ionic detergent having a total base number (TBN) to total acid number (TAN) ratio of at least about 2:1;
wherein said oil-soluble ionic detergent exhibits a TBN of at least about 10 arising from a non-metallic base, and wherein said oil-soluble ionic detergent comprises a stoichiometric excess of quaternary ammonium cations of (a) over organic anions of (b) such that said cations and anions are present in an equivalent ratio (a):(b) of at least about 2:1.