Novel Dispersants

Abstract

The present invention provides a composition comprising: (a) a hydrocarbon fluid; and (b) a dispersant/detergent comprising the structure of Formula (1): (E) p −Z Formula (1), wherein Z is a residue of a polyamine or polyimine; E is (i) a residue of a polyester having a free carboxylic acid group, or (ii) a residue of a hydrocarbyl-substituted acylating agent, with the proviso that if E is the hydrocarbyl-substituted acylating agent, Z is a polyimine, and wherein when E is the hydrocarbyl-substituted acylating agent, the composition has a phosphorus content of 0 ppm to 650 ppm. The invention further provides a use for the composition.

1 . A composition comprising: 
 (a) a hydrocarbon fluid; and    (b) a dispersant/detergent comprising the structure of Formula (1):     (E) p -Z  Formula (1)   wherein    Z is a residue of a polyamine or polyimine;    E is (i) a residue of a polyester having a free carboxylic acid group, or 
 (ii) a residue of a hydrocarbyl-substituted acylating agent,  
 with the proviso that if E is the residue of the hydrocarbyl-substituted acylating agent, Z is a polyimine and the composition has a phosphorus content of 0 ppm to 650 ppm; and  
   p is at least 1.    
   
   
       2 . The composition of  claim 1 , wherein the residue of a polyester having a free carboxylic acid group comprises a residue of formula ((T-(O-A-CO) n (O—B—CO) m ))—, 
 wherein    T is H or a polymerisation terminating group;    A is C2-C40 alkenylene;    B is C2-C40 alkylene;    n is 0 to 50;    m is 0 to 50, provided the sum of m+n is 1 or more; and    p is at least 1.    
   
   
       3 . The composition of  claim 2 , wherein the sum of m+n is less than 15.  
   
   
       4 . The composition of  claim 2 , wherein A (the alkenylene) contains 8-30 carbon atoms; and wherein B (the alkylene) contains 8-30 carbon atoms.  
   
   
       5 . The composition of  claim 1 , wherein the hydrocarbyl-substituted acylating agent comprises a polyisobutylene succinic anhydride.  
   
   
       6 . The composition of  claim 1 , wherein the polyimine is a poly (C 2-6 -alkyleneimine).  
   
   
       7 . The composition of  claim 1 , wherein the polyimine has a number-average molecular weight of not less than 350.  
   
   
       8 . The composition of  claim 1 , wherein the polyamine comprises polyalkylenepolyamines.  
   
   
       9 . The composition of  claim 2 , wherein the dispersant of Formula (1) has E defined as the residue of formula ((T-(O-A-CO) n (O—B—CO) m ))—; and Z is the residue of a polyamine.  
   
   
       10 . The composition of  claim 2 , wherein the dispersant of Formula (1) has E defined as the residue of formula ((T-(O-A-CO) n (O—B—CO) m ))—; and Z is the residue of a polyimine.  
   
   
       11 . The composition of  claim 2 , wherein E is the residue of formula ((T-(O-A-CO) n (O—B—CO) m ))— and the weight ratio of ((T-(O-A-CO) n (O—B—CO) m ))— to Z is 8:1 to 30:1.  
   
   
       12 . The composition of  claim 1 , wherein the hydrocarbon fluid is a liquid fuel, an oil of lubricating viscosity or an unrefined or partially refined heterogeneous fluid.  
   
   
       13 . The composition of  claim 1 , wherein the hydrocarbon fluid is an oil of lubricating viscosity; and wherein the dispersant of Formula (1) has E defined as the hydrocarbyl-substituted acylating agent; and Z is the residue of a polyimine.  
   
   
       14 . The composition of  claim 13 , wherein the composition has a phosphorus content of 0 ppm to 650 ppm; and a sulphur content of 0.5 wt % or less.  
   
   
       15 . The composition of  claim 13 , further comprising a metal dialkyldithiophosphate present at less than 0.6 wt %.  
   
   
       16 . The composition of  claim 13 , wherein the composition has a total sulphated ash content of less than 1.0 wt %; a sulphur content of 1 ppm to 0.1 wt % or less; and a phosphorus content of 0 ppm to 650 ppm.  
   
   
       17 . A method for lubricating an internal combustion engine, comprising supplying thereto a lubricant comprising the composition of  claim 1 , wherein the hydrocarbon fluid is an oil of lubricating viscosity.  
   
   
       18 . A method for fuelling an internal combustion engine, comprising supplying thereto a fuel comprising the composition of  claim 1 , wherein the hydrocarbon fluid is a liquid fuel.  
   
   
       19 . A method of asphaltene control in an unrefined or partially refined heterogeneous fluid, the method comprising employing therein a dispersant/detergent of Formula (1) 
       (E) p -Z  Formula (1) 
     wherein 
 Z is a residue of a polyamine or polyimine;  
 E is (i) a residue of a polyester having a free carboxylic acid group, or 
 (ii) a residue of a hydrocarbyl-substituted acylating agent,  
 with the proviso that if E is the residue of the hydrocarbyl-substituted acylating agent, Z is a polyimine; and p is at least 1.  
 
 
   
   
       20 . A process for preparing a composition, comprising: 
 (1) mixing 
 (a) an aliphatic hydrocarbon solvent; and  
 (b) a hydrocarbyl-substituted acylating agent to form a mixture;  
   (2) reacting component (b) of the mixture with a polyimine to form a dispersant/detergent additive; and    (3) adding a hydrocarbon fluid to the mixture of step (1), to the reactants during step (2), to the dispersant/detergent additive formed in step (2), or a combination thereof.