Pigment dispersions containing aminated acrylic macromonomer dispersant

Abstract

A pigment dispersion useful for forming coating compositions containing dispersed pigment, a carrier solvent and an aminated macromonomer dispersant (binder) is disclosed. The aminated macromonomer dispersant is preferably prepared by the reaction of terminally unsaturated macromonomers synthesized by cobalt-catalyzed chain transfer free radical polymerizations of methacrylic monomers with monomeric or oligomeric amines.

1 . A pigment dispersion composition useful for forming coating compositions comprising a dispersed pigment, a liquid carrier and an aminated macromonomer dispersant; wherein:
 the aminated macromonomer dispersant comprises the structure   
     
       
         
         
             
             
         
       
       wherein each R 1  and R 2  are independently H, alkyl of 1-20 carbon atoms, aryl, substituted alkyl of 1-20 carbon atoms, or substituted aryl; R 3  and R 4  are independently H, alkyl of 1-100 carbon atoms, or substituted alkyl of 1-100 non-hydrogen atoms or R 3  is a polymer; R 5  is methyl, hydrogen or hydroxymethyl; n=1-100; m=1-100 or m+m′=2-100 and is equal to or less than the number of reactive amino groups on R 3 , and; R 6  are independently-CN, —CO 2 R 1 , —COR 1 , or —CONR 1 R 1 . 
     
   
   
       2 . The dispersion of  claim 1  wherein R 3  is derived from a polymeric amine. 
   
   
       3 . The dispersion of  claim 1  wherein R 3  is derived from polyethyleneimine. 
   
   
       4 . The dispersion of  claim 1  wherein R 3  is derived from a polymeric and polyfunctional amine. 
   
   
       5 . The dispersion of  claim 1  wherein R 2  is derived from a macromonomer of an alkyl methacrylate. 
   
   
       6 . The dispersion of  claim 1  wherein the weight ratio of pigment to said aminated macromonomer dispersant is about 1/100-200/100. 
   
   
       7 . The dispersion of  claim 1  wherein R 3  is derived from polyethyleneimine and R 2  is derived from a macromonomer of an alkyl methacrylate. 
   
   
       8 . The dispersion of  claim 1  wherein R 3  is derived from an N-aminoalkylphthalimide, an N-aminoalkylsaccharin, an aminoalkyl ester of nitrobenzoic acid or an aminoalkyl ester of benzoic acid and R 2  is derived from a macromonomer of an alkyl methacrylate. 
   
   
       9 . A coating composition comprising the pigment dispersion composition of  claim 1 . 
   
   
       10 . A substrate coated with a dried and cured layer of the coating composition of  claim 9 . 
   
   
       11 . A process for preparing the pigment dispersion of  claim 1 , wherein said process comprises:
 a) reacting a macromonomer having one terminal ethylenically unsaturated bond with an amine compound to form an aminated macromonomer dispersant wherein:
 the resulting aminated macromonomer dispersant comprises the structure 
   
     
       
         
         
             
             
         
       
       
         wherein each R 1  and R 2  are independently H, alkyl of 1-20 carbon atoms, aryl, substituted alkyl of 1-20 carbon atoms, or substituted aryl; R 3  and R 4  are independently H, alkyl of 1-100 carbon atoms, or substituted alkyl of 1-100 non-hydrogen atoms or R 3  is a polymer; R 5  is methyl, hydrogen or hydroxymethyl; n=1-100; m=1-100 or m+m′=2-100 and is equal to or less than the number of reactive amino groups on R 3 , and; R 6  are independently —CN, —CO 2 R 1 , —COR 1 , or —CONR 1 R 1 ; 
       
       b) forming, in an organic solvent, a dispersion of said aminated macromonomers of step (a); and 
       c) dispersing pigment in the aminated macromonomer dispersion to form said pigment dispersion. 
     
   
   
       12 . The pigment dispersion of  claim 1  wherein said liquid carrier is an aqueous medium or organic solvent.