Lubricating Composition Containing an Antiwear Agent

Abstract

The invention provides a lubricating composition containing an antiwear agent and an oil of lubricating viscosity. The invention further relates to the use of the lubricating composition in an internal combustion engine, or a driveline device.

What is claimed is: 
     
         1 - 22 . (canceled) 
     
     
         23 . A lubricating composition comprising an oil of lubricating viscosity and 0.01 wt % to 2 wt % a non-metallic cationic pnictogen salt of a hydroxy-carboxylic acid, or mixtures thereof,
 wherein the non-metallic cationic pnictogen salt of a hydroxy-carboxylic acid is an amine salt or ammonium salt of a hydroxy-carboxylic acid, wherein the hydroxycarboxylic acid is represented by the formula:   
       
         
           
           
               
               
           
         
         wherein 
         n and m are independently integers of 1 to 5; 
         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  is 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  of the —OR 2  group per molecule is hydrogen, and at least one R of the —Y—R group per molecule is —H (i.e., —Y—R group is —OH) 
         wherein the hydroxy-carboxylic acid is glycolic acid (n and m both equal 1), malic acid (n=2, m=1), tartaric acid (n and m both equal 2), citric acid (n=3, m=1), or mixtures thereof. 
       
     
     
         24 . The lubricating composition of  claim 23 , wherein the ammonium salt comprises a tertiary or a quaternary ammonium salt. 
     
     
         25 . The lubricating composition of  claim 23 , wherein lubricating composition contains 0.05 wt % to 0.1 wt % of the non-metallic cationic pnictogen salt of a hydroxy-carboxylic acid, or mixtures thereof. 
     
     
         26 . The lubricating composition of  claim 23 , wherein lubricating composition contains 0.03 wt % to 0.5 wt % of the non-metallic cationic pnictogen salt of a hydroxy-carboxylic acid, or mixtures thereof. 
     
     
         27 . The lubricating composition of  claim 23 , wherein lubricating composition contains 0.05 wt % to 0.1 wt % of either (i) an amine salt or (ii) a quaternary ammonium salt of a hydroxy-carboxylic acid, or (iii) mixtures thereof. 
     
     
         28 . The lubricating composition of  claim 23  further comprising a zinc dialkyldithiophosphate. 
     
     
         29 . The lubricating composition of  claim 23  further comprising an overbased detergent, wherein the overbased detergent is typically selected from the group consisting of phenates, sulphur containing phenates, sulphonates, salixarates, salicylates, and mixtures thereof. 
     
     
         30 . The lubricating composition of  claim 23 , wherein the lubricating composition is characterised as having (i) a sulphur content of 0.5 wt % or less, (ii) a phosphorus content of 0.1 wt % or less, and (iii) a sulphated ash content of 1.5 wt % or less. 
     
     
         31 . A method of lubricating an internal combustion engine comprising supplying to the internal combustion engine a lubricating composition of  claim 23 . 
     
     
         32 . The method of  claim 31 , wherein the internal combustion engine has an aluminium alloy, an aluminium composite or a steel (i.e., iron-containing) surface on a cylinder bore, cylinder block, or piston ring. 
     
     
         33 . The method of  claim 31 , wherein the internal combustion engine has a steel surface on a cylinder bore, cylinder block, or piston ring. 
     
     
         34 . The method of  claim 31 , wherein the internal combustion engine has a surface of steel, or an aluminium alloy, or an aluminium composite. 
     
     
         35 . A method of lubricating a driveline device comprising supplying to the driveline device a lubricating composition of  claim 23 . 
     
     
         36 . The method of  claim 35 , wherein the driveline device includes a manual transmission that may or may not contain a synchronizer system, or an automatic transmission, or an axle. 
     
     
         37 . The method of any  claim 35 , wherein the lubricating composition has a sulphur-content of greater than 0.5 wt % to 3 wt % of the lubricating composition. 
     
     
         38 . The method of any  claim 35 , wherein the lubricating composition has a phosphorus content of 450 ppm to 4000 ppm.