Lubricating composition containing an antiwear agent

1. A method of lubricating a driveline device comprising supplying to the driveline device a lubricating composition comprising an oil of lubricating viscosity and 0.01 to 5 wt % of a product obtained/obtainable by reacting:

(i) a hydroxy-containing carboxylic compound, wherein the hydroxy-containing carboxylic compound is derived from glycolic acid, malic acid, tartaric acid, citric acid, or mixtures thereof, a (thio)phosphorylating agent, or reactive equivalents thereof, and optionally an alcohol, and

optionally (ii) reacting the product of (i) with an amine, or mixtures thereof, wherein the driveline device includes a manual transmission that may or may not contain a synchronizer system, or an automatic transmission, or an axle.

2. The method of claim 1 , wherein the product is present at 0.1 wt % to 1 wt of the lubricating composition.

3. The method of claim 1 , wherein the product is present at 0.2 wt % to 0.5 wt % of the lubricating composition.

4. The method of claim 1 , wherein the hydroxy-containing carboxylic compound is represented by the formulae:

wherein

n and m are independently integers of 1 to 5, wherein

n and m both equal 1,

n=2, m=1,

n and m both equal 2, or

n=3, m=1;

X is an aliphatic or alicyclic group, or an aliphatic or alicyclic group containing an oxygen atom in the carbon chain, or a substituted group of the foregoing types, said group containing up to 6 carbon atoms and having n+m available points of attachment;

each Y is independently —O—, >NH, or >NR 1 or two Ys together representing the nitrogen of an imide structure R—N< formed between two carbonyl groups; and

each R and R 1 are independently hydrogen or a hydrocarbyl group, provided that at least one R or R 1 group is a hydrocarbyl group; each R 2 is independently hydrogen, a hydrocarbyl group or an acyl group, further provided that at least one —OR 2 group is located on a carbon atom within X that is α or β to at least one of the —C(O)—Y—R groups, and with the proviso that at least one R 2 group is hydrogen.

5. The method of claim 1 , wherein the hydroxy-containing carboxylic compound is derived from tartaric acid or glycolic acid.

6. The method of claim 1 , wherein the hydroxy-containing carboxylic compound is a partially esterified polyol, or mixtures thereof.

7. The method of claim 1 , wherein the hydroxy-containing carboxylic compound is glycerol monooleate or glycerol dioleate.

8. The method of claim 1 , wherein the (thio)phosphorylating agent, or reactive equivalents thereof is POCl 3 , P 2 O 5 , P 4 O 10 , polyphosphoric acid, P 2 S 5 , or P 4 S 10 , or mixtures thereof.

9. The method of claim 1 , wherein the (thio)phosphorylating agent, or reactive equivalents thereof is POCl 3 , P 2 O 5 , P 4 O 10 , or polyphosphoric acid.

10. The method of claim 1 , wherein the product is obtained/obtainable by reacting: (i) a hydroxy-containing carboxylic compound, a sulphur-free phosphating agent, optionally an alcohol, and optionally (ii) reacting the product of (i) with an amine, or mixtures thereof.

11. The method of claim 1 , wherein the amine is a branched secondary or tertiary monoamine, or mixtures thereof.

12. The method of claim 1 , wherein the alcohol is a monohydric alcohol and wherein the monohydric alcohol 8 to 15 carbon atoms.

13. The method of claim 1 , wherein the alcohol is a branched alcohol containing 8 to 20 carbon atoms.

14. The method of claim 1 , wherein the relative amounts of the hydroxy-containing carboxylic compound to the alcohol may be 1:0 to 0.2:0.8.

15. The method of claim 1 , wherein the (thio)phosphorylating agent, or reactive equivalents thereof, is reacted with the hydroxy-containing carboxylic compound (and optionally the alcohol) in a ratio of 1 to 2.5 moles of hydroxyl groups per 1 mole of phosphorus from the (thio)phosphorylating agent, or reactive equivalents thereof.