Lubricating composition containing a dispersant

Abstract

The invention provides a lubricating composition containing a compound comprising the reaction product of a polyolefin, an ethylenically unsaturated aromatic acylating agent (or carboxylic reactant), and an amine, and an oil of lubricating viscosity. The invention further relates to the use of the lubricating composition in an internal combustion engine.

What is claimed is: 
     
         1 . A lubricating composition comprising:
 (a) an oil of lubricating viscosity,   (b) a compound comprising the reaction product of a polyisobutylene, an ethylenically unsaturated aromatic acylating agent (or carboxylic reactant), and an amine   (c) an overbased metal-containing detergent, and   (d) a succinimide dispersant.   
     
     
         2 . The lubricating composition of  claim 1 , wherein the amine is an acyclic polyamine. 
     
     
         3 . The lubricating composition of  claim 2 , wherein the acyclic polyamine is an ethylenepolyamine. 
     
     
         4 . The lubricating composition of  claim 3 , wherein the ethylenepolyamine is selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyamine still bottoms, and mixtures thereof. 
     
     
         5 . The lubricating composition of  claim 1 , wherein the ethylenically unsaturated aromatic acylating agent (or carboxylic reactant) is selected from cis-cinnamic acid, trans-cinnamic acid, and mixtures thereof. 
     
     
         6 . The lubricating composition of  claim 1 , wherein the compound is non-borated. 
     
     
         7 . The lubricating composition of  claim 1 , wherein the compound (b) is present at 0.1 wt % to 15 wt % of the lubricating composition. 
     
     
         8 . The lubricating composition of  claim 1 , wherein the lubricating composition has a sulphated ash content of 0.3 wt % to 1.2 wt %. 
     
     
         9 . The lubricating composition of  claim 1 , wherein the overbased metal-containing detergent is selected from the group consisting of non-sulphur containing phenates, sulphur containing phenates, sulphonates, salixarates, salicylates, and mixtures thereof. 
     
     
         10 . The lubricating composition of  claim 9 , wherein the overbased metal-containing detergent is a sodium, calcium or magnesium salt of a phenate, sulphur containing phenate, sulphonate, salixarate or salicylate, wherein the salixarate, phenate or salicylate has a total base number of 180 to 450 TBN, and wherein the sulphonate has a total base number of 250 to 600. 
     
     
         11 . The lubricating composition of  claim 1 , wherein the lubricating composition contains 0.2 wt % to 3 wt % of the overbased metal-containing detergent. 
     
     
         12 . The lubricating composition of  claim 1 , wherein the polyisobutylene has a number average molecular weight of 350 to 5000. 
     
     
         13 . The lubricating composition of  claim 12 , wherein the polyisobutylene has a number average molecular weight of 550 to 3000. 
     
     
         14 . The lubricating composition of  claim 13 , wherein the polyisobutylene has a number average molecular weight of 750 to 2500 
     
     
         15 . A method of lubricating an internal combustion engine comprising supplying to the internal combustion engine a lubricating composition comprising the lubricating composition of  claim 1 . 
     
     
         16 . A lubricating composition comprising:
 a. an oil of lubricating viscosity,   b. 0.1 wt % to 15 wt % of a first dispersant, wherein the first dispersant comprises the reaction product of a polyisobutylene, an ethylenically unsaturated aromatic acylating agent (or carboxylic reactant), and an acyclic amine,   c. 0.1 wt % to 10 wt % of an overbased metal-containing detergent, and   d. 0.1 wt % to 10 wt % of a second dispersant other than the first dispersant, wherein the second dispersant is a succinimide dispersant.   
     
     
         17 . The lubricating composition of  claim 17 , wherein the wherein the acyclic amine is selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyamine still bottoms, and mixtures thereof.