Lubricating oil compositions for internal combustion engines with improved wear performance

Abstract

The present invention concerns a lubricating oil composition comprising an oil of lubricating viscosity; about 0.05 to about 5 weight percent of an organo molybdenum compound; and about 0.1 to about 12 weight percent of a borated polyisobutenyl mono- and bis-succinimide wherein the polyisobutenyl group has a molecular weight (Mn) from about 500 to about 2300.

What is claimed is:  
     
         1 . A lubricant additive comprising: 
 (a) at least one organo molybdenum compound; and    (b) borated polyisobutenyl mono- and bis-succinimide wherein the polyisobutenyl group has a molecular weight (Mn) from about 500 to about 2300.    
     
     
         2 . A lubricating oil composition comprising: 
 (a) an oil of lubricating viscosity;    (b) about 0.05 to about 5 weight percent of an organo molybdenum compound; and    (c) about 0.1 to about 12 weight percent of a borated polyisobutenyl mono- and bis-succinimide wherein the polyisobutenyl group has a molecular weight (Mn) from about 500 to about 2300.    
     
     
         3 . The lubricating oil of  claim 2  wherein the oil of lubricating viscosity is selected from the group consisting of Group II, Group III, and synthetic base stocks.  
     
     
         4 . The lubricating oil of  claim 3  wherein the synthetic base stock is a polyalphaolefin.  
     
     
         5 . The lubricating oil of  claim 3  additionally comprising at least one co-basestock selected from the group consisting of hydrocarbyl aromatic and ester base stocks.  
     
     
         6 . The lubricating oil of  claim 3  wherein the molybdenum compound is at least one compound selected from the group consisting of molybdenum phosphorodithioates, molybdenum complexes of amines, alcohols and/or esters, molybdenum dithiocarbamates, and molybdenum (trimeric) dithiocarbamates.  
     
     
         7 . The lubricating oil of  claim 6  wherein the organic molybdenum compound is present in an amount of about 0.1 to about 3 weight percent.  
     
     
         8 . The lubricating oil composition of  claim 7  where in the borated polyisobutenyl mono- and bis-succinimide compound is present in an amount of about 0.5 to about 8 weight percent.  
     
     
         9 . The lubricating oil of  claim 8  wherein the lubricating oil is a Group II, Group III, or Gas-to-Liquids base stock.  
     
     
         10 . The lubricating oil of any one of the claims  2  through  9  wherein the borated polyisobutenyl mono- and bis-succinimide is present at about 20% of the total borated succinimide.  
     
     
         11 . A method of improving wear performance of a lubricating oil composition comprising the step of adding the following to the lubricating oil: 
 (i) about 0.05 to about 5 weight percent of an organo molybdenum compound; and    (ii) about 0.1 to about 12 weight percent of a borated polyisobutenyl mono- and bis-succinimide wherein the polyisobutenyl group has a molecular weight (Mn) from about 500 to about 2300.    
     
     
         12 . The borated polyisobutenyl mono- and bis-succinimide of  claim 1  wherein the mono-succinimide is present at about 20% of the total borated succinimide.  
     
     
         13 . A method of reducing lead loss under catalytic oxidation test conditions of a lubricating oil composition comprising the step of adding the following to the lubricating oil: 
 (i) about 0.05 to about 5 weight percent of an organo molybdenum compound; and    (ii) about 0.1 to about 12 weight percent of a borated polyisobutenyl mono- and bis-succinimide wherein the polyisobutenyl group has a molecular weight (Mn) from about 500 to about 2300.    
     
     
         14 . A method of improving viscosity increase control under high-temperature oxidizing conditions of a lubricating oil composition comprising the step of adding the following to the lubricating oil: 
 (i) about 0.05 to about 5 weight percent of an organo molybdenum compound; and    (ii) about 0.1 to about 12 weight percent of a borated polyisobutenyl mono- and bis-succinimide wherein the polyisobutenyl group has a molecular weight (Mn) from about 500 to about 2300.    
     
     
         15 . The lubricating oil of  claim 6  where the molybdenum compound is present at a concentration sufficient to provide 20 ppm to 1000 ppm molybdenum.