Rheological additives and paint and coating compositions containing such additives exhibiting improved intercoat adhesion

Abstract

An improved thickening composition for organic systems, including paints and coatings, is described. The additive provides paints and coatings more than adequate viscosity improvement without affecting intercoat adhesion characteristics.

1 .- 18 . (canceled) 
     
     
         19 . A method to make a rheological additive comprising the step of:
 a) conducting a condensation reaction of a reactant mixture consisting of:
 i. a diamine selected from the group consisting of ethylene diamine and hexamethylene diamine; 
 ii. one or more straight chain monocarboxylic acids selected from the group consisting of pentanoic acid, hexanoic acid, heptanoic acid and octanoic acid; and 
 iii. 12-hydroxystearic acid; 
   b) periodically measuring an acid value and an amine value; and   c) ceasing the condensation reaction when the acid value is less than 10 and the amine value is less than 10.   
     
     
         20 . The method of  claim 19 , wherein the reactant mixture consists of:
 i. 2 equivalents of said diamine;   ii. from 0.4 to 1.8 equivalents of one or more of said straight chain monocarboxylic acids having 3 to 7 carbon atoms in the straight chain saturated aliphatic hydrocarbon radical; and   iii. from 1.6 to 0.2 equivalents of 12-hydroxystearic acid.   
     
     
         21 . The method of  claim 19 , wherein the reactant mixture consists of:
 i. 2 equivalents of ethylene diamine;   ii. from 0.4 to 1.6 equivalents of one or more straight chain monocarboxylic acids having 3 to 7 carbon atoms in the straight chain saturated aliphatic hydrocarbon radical; and   iii. from 1.6 to 0.2 equivalents of 12-hydroxystearic acid.   
     
     
         22 . The method of  claim 19 , wherein the condensation reaction is conducted neat. 
     
     
         23 . The method of  claim 19 , wherein the diamine is ethylene diamine. 
     
     
         24 . The method of  claim 23 , wherein the straight chain monocarboxylic acid is hexanoic acid. 
     
     
         25 . The method of  claim 19 , wherein such condensation reaction is conducted until that there is no unreacted diamine and unreacted straight chain monocarboxylic acid.