Lubricating composition

Abstract

Use of a nitrogen-containing ashless dispersant in a lubricating composition for the purpose of reducing wear in the presence of ZDTP and soot wherein the nitrogen-containing ashless dispersant has a Functionality (F) of greater than 1.4.

1 . A lubricating composition for the purpose of reducing wear in the presence of a zinc dithiophosphate compound and soot, the lubricating composition comprising a nitrogen-containing ashless dispersant that has a Functionality (F) of greater than 1.4. 
     
     
         2 . The lubricating composition of  claim 1 , wherein the nitrogen-containing ashless dispersant has a Functionality (F) of greater than 1.5. 
     
     
         3 . The lubricating composition of  claim 1 , wherein the nitrogen-containing ashless dispersant comprises a functionalized oil-soluble polymeric hydrocarbon backbone which has been derivatized with a nitrogen-containing nucleophilic reactant. 
     
     
         4 . The lubricating composition of  claim 3 , wherein the nitrogen-containing nucleophilic reactant is selected from an amine, amino-alcohol, amide, or mixture thereof. 
     
     
         5 . The lubricating composition of  claim 3 , wherein the nitrogen-containing nucleophilic reactant is an amine. 
     
     
         6 . The lubricating composition of  claim 1 , wherein the nitrogen-containing ashless dispersant comprises at least one polyalkenyl succinimide, which is the reaction product of a polyalkenyl substituted succinic anhydride and a polyamine. 
     
     
         7 . The lubricating composition of  claim 1 , wherein the nitrogen-containing ashless dispersant comprises at least one polyisobutylene succinimide. 
     
     
         8 . The lubricating composition of  claim 1 , wherein the nitrogen-containing dispersant is present in the lubricating composition at a level such as to provide a level of nitrogen of from 0.001 wt % to 15 wt %, by weight of the lubricating composition. 
     
     
         9 . The lubricating composition of  claim 1 , wherein the nitrogen-containing dispersant is present in the lubricating composition at a level such as to provide a level of nitrogen of from 0.05 wt % to 0.1 wt %, by weight of the lubricating composition. 
     
     
         10 . The lubricating composition of  claim 1 , wherein the lubricating composition comprises a base oil and one or more additives.