Tartaric Acid Derivatives as Fuel Economy Improvers and Antiwear Agents in Crankcase Oils and Preparation Thereof

Abstract

Formulations using tartaric compounds of the present invention in a low sulfur, low ash and low phosphorous lubricant lower wear, and friction and improves fuel economy.

1 . A low-sulfur, low-phosphorus, low-ash lubricant composition suitable for use in an internal combustion engine, comprising:
 (a) an oil of lubricating viscosity, and   (b) a condensation product of a material represented by formula I and an alcohol having 6 to 12 carbon atoms;   
       
         
           
           
               
               
           
         
       
       wherein each R is independently H, or a hydrocarbyl group, or wherein the R groups together form a ring; and wherein if R is H, the condensation product is optionally further functionalized by acylation or reaction with a boron compound;
 wherein said lubricant composition has a sulfated ash value of up to about 1.0, a phosphorus content of up to about 0.08 percent by weight and a sulfur content of up to about 0.4 percent by weight. 
 
     
     
         2 . The composition of  claim 1 , wherein the alcohol is linear, branched or mixtures thereof. 
     
     
         3 . The composition of  claim 1 , wherein the alcohol has about 8 to about 10 carbon atoms. 
     
     
         4 . The composition of  claim 1 , wherein the condensation product (b) is a linear C 8-10  alkyl tartrate ester. 
     
     
         5 . The composition of  claim 1 , wherein the amount of the condensation product is about 0.05 to about 5.0 percent by weight. 
     
     
         6 . The composition of  claim 5 , wherein the amount of condensation product is about 0.1 to about 2.0 percent by weight. 
     
     
         7 . The composition of  claim 6 , wherein the amount of condensation product is about 0.25 to about 1.25 percent by weight. 
     
     
         8 . The composition of  claim 1 , further comprising a metal dialkyldithiophosphate. 
     
     
         9 . The composition of  claim 1 , wherein the metal dialkyldithiophosphate is zinc dialkyldithiophosphate wherein at least about 50 percent of the alkyl groups thereof are secondary alkyl groups. 
     
     
         10 . The composition of  claim 1 , further comprising a dispersant. 
     
     
         11 . The composition of  claim 10 , wherein the dispersant is a succinimide. 
     
     
         12 . The composition of  claim 1 , further comprising at least one calcium overbased detergent. 
     
     
         13 . The composition of  claim 12 , wherein the calcium overbased detergent is selected from the group consisting of calcium sulfonates, calcium phenates, calcium salicylates, calcium salixarates and mixtures thereof. 
     
     
         14 . The composition of  claim 1 , further comprising at least one antioxidant. 
     
     
         15 . The composition of  claim 14 , wherein the antioxidant is selected from the group consisting of hindered phenols, aryl amines and mixtures thereof. 
     
     
         16 . The composition of  claim 1 , further comprising additional friction modifiers other than (b). 
     
     
         17 . The composition of  claim 16 , wherein the additional friction modifiers are selected from the group consisting of glycerol monooleates, oleyl amides, diethanol fatty amines and mixtures thereof. 
     
     
         18 . The composition of  claim 1 , further comprising a defoamer. 
     
     
         19 . A method of lubricating an internal combustion engine, comprising supplying to said engine an oil of lubricating viscosity, and a condensation product of a material represented by formula I and an alcohol having 6 to 12 carbon atoms; 
       
         
           
           
               
               
           
         
       
       wherein in the product each R is independently H or a hydrocarbyl group, or wherein the R groups together form a ring; or wherein if R is H, then the resulting hydroxyl group is further functionalized by acylation or reaction with a boron compound;
 wherein said lubricant composition has a sulfated ash value of up to about 1.0, a phosphorus content of up to about 0.08 percent by weight and a sulfur content of up to about 0.4 percent by weight. 
 
     
     
         20 . The method of making a lubricant composition comprising:
 (a) blending an oil of lubricating viscosity and a condensation product of a material represented by formula I and an alcohol having 6 to 12 carbon atoms;   
       
         
           
           
               
               
           
         
         wherein in the product each R is independently H or a hydrocarbyl group, or wherein the R groups together form a ring; or wherein if R is H, then the resulting hydroxyl group is further functionalized by acylation or reaction with a boron compound; 
         resulting in a lubricant composition wherein said lubricant composition has a sulfated ash value of up to about 1.0, a phosphorus content of up to about 0.08 percent by weight and a sulfur content of up to about 0.4 percent by weight.