Lubricating oil additive comprising EC-treated succinimide, borated dispersant and corrosion inhibitor

Abstract

An additive formulation comprising one or more ec-treated dispersants, borated dispersants, and a dispersed aromatic dicarboxylic acid corrosion inhibitor; a dispersant inhibitor package comprising one or more ec-treated dispersants, borated dispersants, and a dispersed aromatic dicarboxylic acid corrosion inhibitor; a lubricating oil comprising said dispersant inhibitor package; and a method for lubricating engines.

What is claimed is:  
     
         1 . A lubricating oil additive composition comprising: 
 (a) one or more ethylene carbonate-treated succinimides;    (b) one or more borated succinimides, and    (c) one or more dispersed aromatic dicarboxylic acid corrosion inhibitors which are succinimide salts of one or more aromatic dicarboxylic acids.    
     
     
         2 . The lubricating oil additive composition of  claim 1 , wherein the corrosion inhibitors are one of more succinimide salts of terephthalic acid.  
     
     
         3 . The lubricating oil additive composition of  claim 2 , wherein the succinimide salts of terephthalic acid are polyisobutenyl succinimide salts.  
     
     
         4 . The lubricating oil additive composition of  claim 1 , wherein the ethylene carbonate-treated succinimide is a polybutene succinimide derived from the reaction product of a polyisobutenyl succinic anhydride with a polyamine.  
     
     
         5 . The lubricating oil additive composition of  claim 4 , wherein the ethylene carbonate-treated succinimide is derived from polybutenes having a molecular weight of from at least 1800.  
     
     
         6 . The lubricating oil additive composition of  claim 1 , wherein the borated succinimide is derived from the reaction product of a polyisobutenyl succinic anhydride with a polyamine.  
     
     
         7 . The lubricating oil additive composition of  claim 6 , wherein the borated succinimide is derived from polybutenes having a molecular weight of from 1200 to 1400.  
     
     
         8 . A lubricating oil composition comprising a major amount of an oil of lubricating viscosity and a lubricating oil additive composition comprising: 
 (a) one or more ethylene carbonate treated succinimides,    (b) one or more borated succinimides, and    (c) one or more dispersed aromatic dicarboxylic acid corrosion inhibitors which are succinimide salts of one or more aromatic dicarboxylic acids.    
     
     
         9 . A method for lubricating an internal combustion engine comprising contacting the engine with a lubricating oil composition of  claim 8 .  
     
     
         10 . The method of  claim 9 , wherein the internal combustion engine is a heavy duty diesel engine.  
     
     
         11 . A method for reducing bearing corrosion in a diesel engine which comprises operating the engine with a lubricating oil composition of  claim 8.