Antiwear inhibiting and load enhancing additive combinations for lubricating oils

Abstract

The anti-wear and load carrying properties of lubricating oils is enhanced by the addition of the combination of thiosalicylic acid and adenine. Phosphate ester anti-wear and load carrying additives may be employed with the combination of thiosalicylic acid and adenine.

1 . A lubricating composition comprising: 
 (a) a major amount of an oil of lubricating viscosity, and    (b) an effective amount of an additive combination comprising thiosalicylic acid and adenine.    
   
   
       2 . The composition of  claim 1  wherein the weight ratio of thiosalicylic acid to adenine is in the range of about 5:1 to about 50:1.  
   
   
       3 . The composition of  claim 2  wherein the combined thiosalicylic acid and adenine comprises about 0.01 wt % to about 1.0 wt % based on the total weight of composition.  
   
   
       4 . The composition of  claim 2  wherein the lubricating composition includes a phosphate ester anti-wear and load carrying additive.  
   
   
       5 . The composition of  claim 4  wherein the anti-wear and load carrying additive is tricresyl phosphate.  
   
   
       6 . The composition of  claim 4  wherein the anti-wear and load carrying additive is a phosphate oligomer.  
   
   
       7 . The composition of  claim 3  wherein the additive combination and phosphate ester additive comprises from about 0.1 to about 5.0 wt % of the total lubricating composition.  
   
   
       8 . The composition of  claim 5  wherein the weigh ratio of the combined thiosalicylic acid and adenine to tricresyl phosphate is in the range of about 1:1 to about 1:50.  
   
   
       9 . The composition of claims  1  and  5  wherein the oil of lubricating viscosity is a gas to liquid base oil.  
   
   
       10 . The composition of claims  1  and  6  wherein the oil of lubricating viscosity is an ester base oil.  
   
   
       11 . A lubricating oil additive combination comprising thiosalicylic acid and adenine in the weight ratio of about 50:1 to about 5:1.  
   
   
       12 . The additive of  claim 11  including an anti-wear and load carrying phosphate ester additive wherein the weight ratio of the combined thiosalicylic acid and adenine to phosphate ester additive is in the range of about 1:1 to about 1:50.  
   
   
       13 . The additive of  claim 12  wherein the phosphate ester is tricresyl phosphate.  
   
   
       14 . The additive of  claim 12  wherein the phosphate ester is a phosphate oligomer.  
   
   
       15 . A method for enhancing the antiwear and load carrying performance of a lubricating oil comprising adding from about 0.5 to about 15 wt % of an additive of any one of  claims 12  to  14 .