Dispersing polymers

Abstract

A pigment dispersing polymer comprising a backbone having one or more urea groups and having polymeric side chains extending therefrom. The dispersing polymer may be formed from the reaction of a compound having one or more carbodiimide groups with acid functional resins such as acid functional polyesters, acid functional acrylics, acid functional polyethers, and fatty acids.

1 . A polymer comprising the reaction product of:
 (a) an acid functional resin; and   (b) a compound comprising one or more reactive carbodiimide groups and an acid functional resin;   wherein when the polymer and pigment are physically mixed in a carrier liquid, the polymer is capable of dispersing the pigment in the carrier liquid.   
   
   
       2 . The polymer of  claim 1 , wherein the acid functional resin is an acid functional polycaprolactone. 
   
   
       3 . The polymer of  claim 2 , wherein the acid functional polycaprolactone is the product of ring opening polymerization of caprolactone initiated by dimethylolpropionic acid. 
   
   
       4 . The polymer of  claim 1 , wherein the acid functional resin is selected from mono-acid functional polyesters, acid functional polycaprolactones, fatty acids, the reaction product of a hydroxyl or amino functional polyether with anhydride, fatty acid, or mixtures thereof. 
   
   
       5 . The polymer of  claim 1 , wherein the compound including at least one reactive carbodiimide group comprises at least 4 reactive carbodiimide groups. 
   
   
       6 . The polymer of  claim 3 , wherein the polymer comprises a backbone having repeating acyl urea groups. 
   
   
       7 . The polymer of  claim 4 , further comprising at least one polymeric side chain attached to the backbone. 
   
   
       8 . The polymer of  claim 1 , wherein the polymer comprises a backbone comprising at least one acyl urea group and at least one polymeric side chain. 
   
   
       9 . The polymer of  claim 1 , wherein the number average molecular weight is at least about 500. 
   
   
       10 . The polymer of  claim 1 , wherein the number average molecular weight is about 3000 to about 12,000. 
   
   
       11 . The polymer of  claim 1 , wherein the molar ratio of reactive carbodiimide groups to acid groups on the acid functional resin is about 0.5:1 to about 5:1. 
   
   
       12 . The polymer of  claim 1 , wherein the molar ratio of reactive carbodiimide groups to acid groups on the acid functional resin is about 1:1 to about 2:1. 
   
   
       13 . A dispersion comprising:
 (a) a polymer comprising the reaction product of
 (i) a compound comprising one or more reactive carbodiimide groups, and 
 (ii) an acid functional resin or a blend of acid functional resins; 
   (b) at least one pigment; and   (c) a carrier liquid,   
     wherein when the polymer and at least one pigment are physically mixed in the carrier liquid, the polymer is capable of dispersing the pigment in the carrier liquid. 
   
   
       14 . The polymer of  claim 13 , wherein the acid functional resin is selected from mono-acid functional polyesters, acid functional polycaprolactones, fatty acids, the reaction product of a hydroxyl or amino functional polyether with anhydride, fatty acid, or mixtures thereof. 
   
   
       15 . The dispersion of  claim 13 , wherein said compound comprising one or more reactive carbodiimide groups comprises at least 4 reactive carbodiimide groups. 
   
   
       16 . The dispersion of  claim 15 , wherein said polymer comprises a backbone having repeating acyl urea groups and one or more side chains attached to the backbone. 
   
   
       17 . The dispersion of  claim 13 , wherein the pigment dispersing polymer comprises a backbone having at least one acyl urea group and at least one polymeric side chain. 
   
   
       18 . The dispersion of  claim 17 , wherein the at least one polymeric side chain has hydroxyl functionality. 
   
   
       19 . The dispersion of  claim 13 , wherein the at least one pigment is an inorganic pigment. 
   
   
       20 . A surface coating composition, said coating composition comprising:
 (a) a polymer comprising the reaction product of
 (i) a compound comprising one or more reactive carbodiimide groups, and 
 (ii) an acid functional resin or a blend of acid functional resins; 
   (b) at least one pigment;   (c) a carrier liquid, wherein when the polymer and at least one pigment are physically mixed in the carrier liquid, the polymer is capable of dispersing the pigment in the carrier liquid; and   (d) a film forming polymer.