Use of Glycerides of Hydroxy Polycarboxylic Acids as Anti-Camshaft-Wear Additives in Lubricants and Fuels

Abstract

This invention relates to the use of an oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy polycarboxylic acid, or a derivative thereof, as an anti-camshaft-wear additive in a non-aqueous lubricant composition and/or in a fuel composition.

1 - 17 . (canceled) 
     
     
         18 . A method of improving anti-camshaft-wear properties of a non-aqueous lubricant composition and/or fuel composition comprising admixing an oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy polycarboxylic acid, or a derivative thereof, in the non-aqueous lubricant composition and/or in the fuel composition. 
     
     
         19 . The method of  claim 18 , wherein the oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy polycarboxylic acid, or a derivative thereof, reduces camshaft wear as measured in the OM646LA engine test. 
     
     
         20 . The method of  claim 18 , wherein the lubricant composition is used to lubricate an internal combustion engine. 
     
     
         21 . The method of  claim 20 , wherein the oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy polycarboxylic acid, or a derivative thereof, is provided in a liquid fuel composition used to operate the internal combustion engine, and a portion at least, of said glyceride ingresses into the lubricating oil composition during operation of said engine. 
     
     
         22 . The method of  claim 18 , wherein the hydroxy polycarboxylic acid has at least one hydroxy group which is in an alpha position with respect to a carboxylic moiety. 
     
     
         23 . The method of  claim 22 , wherein the hydroxy polycarboxylic acid is citric acid. 
     
     
         24 . The method of  claim 18 , wherein the glyceride is a glyceride of at least one hydroxy polycarboxylic acid and at least one second carboxylic acid which is a saturated, mono-unsaturated or poly-unsaturated, branched or linear, monocarboxylic or polycarboxylic acid having 4 to 22 carbon atoms, or a derivative thereof. 
     
     
         25 . The method of  claim 18 , wherein the glyceride is a glyceride of at least one hydroxy polycarboxylic acid and a mono-unsaturated C4 to C22 monocarboxylic acid, or a derivative thereof. 
     
     
         26 . The method of  claim 18 , wherein the glyceride is a glyceride of at least one hydroxy polycarboxylic acid and a polyunsaturated C4 to C22 monocarboxylic acid, or a derivative thereof. 
     
     
         27 . The method of  claim 25 , wherein the glyceride is a glyceride of at least one hydroxy polycarboxylic acid and a mono-unsaturated or polyunsaturated Cis monocarboxylic acid, or a derivative thereof. 
     
     
         28 . The method of  claim 27 , wherein the glyceride is a glyceride of citric acid and a mono-unsaturated or polyunsaturated C18 monocarboxylic acid, or a derivative thereof. 
     
     
         29 . The method of  claim 25 , wherein the mono-unsaturated or polyunsaturated C4 to C22 carboxylic acid is linear. 
     
     
         30 . The method of  claim 18 , wherein the glyceride is a glyceride of citric acid and oleic acid, a glyceride of citric acid and linoleic acid or a mixture thereof. 
     
     
         31 . The method of  claim 24 , wherein the carboxylic acid having 4 to 22 carbon atoms is a polycarboxylic acid and the derivative is an ester of a carboxylic acid moiety of said polycarboxylic acid. 
     
     
         32 . The method of  claim 18 , wherein the derivative of the glyceride is an ether of the hydroxy moiety of the hydroxy polycarboxylic acid. 
     
     
         33 . The method of  claim 18 , wherein the derivative of the glyceride is an ester of the hydroxy moiety of the hydroxy polycarboxylic acid. 
     
     
         34 . The method of  claim 18 , wherein the derivative of the glyceride is an ester of a carboxylic acid moiety of the hydroxy polycarboxylic acid. 
     
     
         35 . The method of  claim 19 , wherein the oil-soluble mono-, di-, or tri-glyceride of at least one hydroxy polycarboxylic acid, or a derivative thereof, is present in an amount of 0.1 to 5% by weight.