Polymeric dispersant viscosity modifier composition

Abstract

The present invention provides a composition containing: (a) an oil of lubricating viscosity; (b) an amine salt of a phosphorus compound; (c) a compound selected from the group consisting of: 1) a polymeric dispersant viscosity modifier wherein the polymeric dispersant viscosity modifier excludes copolymers derived from (a) a nitrogen containing monomer; and (b) methacrylic acid esters containing from about 9 to about 25 carbon atoms in the ester group; 2) a polymeric dispersant viscosity modifier, a borated dispersant; and a sulphurised olefin; and 3) mixtures thereof. The invention further provides a process for preparing the composition and a method for improving oxidation cleanliness of surface.

1 . A composition comprising: 
 (a) an oil of lubricating viscosity;    (b) an amine salt of a phosphorus compound; and    (c) a compound selected from the group consisting of: 
 1) a polymeric dispersant viscosity modifier wherein the polymeric dispersant viscosity modifier excludes copolymers derived from (a) a nitrogen containing monomer; and (b) methacrylic acid esters containing from about 9 to about 25 carbon atoms in the ester group;  
 2) a polymeric dispersant viscosity modifier, a borated dispersant; and a sulphurised olefin; and  
 3) mixtures thereof.  
   
   
   
       2 . The composition of  claim 1 , wherein the amine salt of a phosphorus compound is an extreme pressure agent, a wear preventing agent, a friction modifier or mixtures thereof.  
   
   
       3 . The composition of  claim 1 , wherein the amine salt of a phosphorus compound further comprises a sulphur atom in the molecule.  
   
   
       4 . The composition of  claim 1 , wherein the amine salt of a phosphorus compound contains a hydrocarbyl group on the amine with about 8 to about 26 carbon atoms.  
   
   
       5 . The composition of  claim 1 , wherein the polymeric dispersant viscosity modifier is derived from at least one polymer selected from the group consisting of a poly(meth)acrylate, a functionalised polyolefin, an interpolymer derived from: (i) a vinyl aromatic monomer; and (ii) an unsaturated carboxylic acid or derivatives thereof; and mixtures thereof.  
   
   
       6 . The composition of  claim 1 , wherein the polymeric dispersant viscosity modifier is a poly(meth)acrylate copolymer with a nitrogen containing monomer.  
   
   
       7 . The composition of  claim 6 , wherein the nitrogen containing monomer is a vinyl substituted nitrogen heterocyclic monomer, a dialkylaminoalkyl (meth)acrylate monomer, a dialkylaminoalkyl (meth) acrylamide monomer, a tertiary-(meth)acrylamide monomer or mixtures thereof.  
   
   
       8 . The composition of  claim 6 , wherein the poly(meth)acrylate has a molecular weight (M w ) of about 15,000 to about 150,000.  
   
   
       9 . The composition of  claim 1 , wherein the polymeric dispersant viscosity modifier is a functionalised polyolefin derived from an ethylene monomer and at least one other comonomer derived from an alpha-olefin having the formula H 2 C═CHR 5 , wherein R 5  is a hydrocarbyl group, containing 1 to about 6 carbon atoms.  
   
   
       10 . The composition of  claim 9 , wherein the functionalised polyolefin contains a nitrogen derived from a nitrogen containing compound capable of reacting with a functionalised polymer backbone.  
   
   
       11 . The composition of  claim 9 , wherein the functionalised polyolefin has a molecular weight (M w ) from about 1000 to about 50,000.  
   
   
       12 . The composition of  claim 1 , wherein the polymeric dispersant viscosity modifier is an interpolymer derived from a styrene-maleic anhydride copolymer.  
   
   
       13 . The composition of  claim 12 , wherein the interpolymer has a reduced specific viscosity of about 0.06 to about 1.  
   
   
       14 . The composition of  claim 1 , wherein the borated dispersant is a N-substituted long chain alkenyl succinimide and wherein the sulphurised olefin includes an olefin derived from propylene, isobutylene, pentene or mixtures thereof.  
   
   
       15 . The composition of  claim 1 , wherein: 
 (a) the oil of lubricating viscosity is present at up to about 99.9 wt % of the composition;    (b) the amine salt of a phosphorus compound is present at about 0.001 wt % to 30 wt % of the composition; and    (c) the polymeric dispersant viscosity modifier wherein the polymeric dispersant viscosity modifier excludes copolymers derived from (a) a nitrogen containing monomer; and (b) methacrylic acid esters containing from about 9 to about 25 carbon atoms in the ester group.    
   
   
       16 . The composition of  claim 1 , wherein: 
 (a) the oil of lubricating viscosity is present at up to about 99.9 wt % of the composition;    (b) the amine salt of a phosphorus compound is present at about 0.001 wt % to 30 wt % of the composition;    (c) the polymeric dispersant viscosity modifier is present at about 0.001 wt % to about 60 wt % of the composition;    (d) the borated dispersant is present at 0.01 wt % to about 15 wt % of the composition; and    (e) the sulphurised olefin is present at about 0.001 wt % to 30 wt % of the composition.    
   
   
       17 . A method comprising lubricating a surface while imparting deposit control, the method employing a composition comprising: 
 (a) an oil of lubricating viscosity;    (b) an amine salt of a phosphorus compound; and    (c) a compound selected from the group consisting of: 
 1) a polymeric dispersant viscosity modifier wherein the polymeric dispersant viscosity modifier excludes copolymers derived from (a) a nitrogen containing monomer; and (b) methacrylic acid esters containing from about 9 to about 25 carbon atoms in the ester group;  
 2) a polymeric dispersant viscosity modifier, a borated dispersant; and a sulphurised olefin; and  
 3) mixtures thereof,  
 wherein the surface is a gear, a bearing or mixtures thereof.  
   
   
   
       18 . A process for the preparation of a composition comprising mixing: 
 (a) an oil of lubricating viscosity;    (b) an amine salt of a phosphorus compound; and    (c) a compound selected from the group consisting of: 
 1) a polymeric dispersant viscosity modifier wherein the polymeric dispersant viscosity modifier excludes copolymers derived from (a) a nitrogen containing monomer; and (b) methacrylic acid esters containing from about 9 to about 25 carbon atoms in the ester group;  
 2) a polymeric dispersant viscosity modifier, a borated dispersant; and a sulphurised olefin; and  
 3) mixtures thereof.  
   
   
   
       19 . The use of the composition of  claim 1  for imparting one or more performance characteristics including deposit control, reduced carbon varnish, decreased wear, low temperature viscometrics, high temperature viscometrics or mixtures thereof.