Transition Metal Crosslinking of Acid-Containing Polymers

Abstract

An acid-functional polymer is reacted with a transition metal compound having an average particle size small enough to react with the polymer at a temperature below the glass transition temperature of the polymer, e.g., at room temperature, to produce cross-linked polymer. The process produces a liquid polymer product that dries to a cross-linked film without the required presence of volatile ligands. Improved coatings such as floor polishes that can be formed from these cross-linked polymers are also disclosed.

1 . A composition comprising the product of the reaction in an aqueous system of:
 (a) a polymer prepared from more than one unsaturated monomer, the polymer including from about 4 to about 90 weight percent of acid-functional monomer(s), said polymer having a calculated glass transition temperature less than the decomposition temperature of the polymer, with   (b) a transition metal compound having an average particle size sufficiently small to react with the polymer at a temperature approximately equal to or below the glass transition temperature of said polymer for a time sufficient to produce a degree of reaction of said acid and metal, wherein said reaction product is capable of forming a film.   
     
     
         2 . The composition of  claim 1 , wherein the transition metal is selected from the group consisting of zinc, aluminum, tin, tungsten and zirconium. 
     
     
         3 . The composition of  claim 1 , wherein the transition metal compound is an oxide, hydroxide carbonate or acetate. 
     
     
         4 . The composition of  claim 1  further comprising pigments, fillers wetting, emulsifying, buffering and dispersing agents. 
     
     
         5 . A composition comprising the product of the reaction in an aqueous system of:
 (a) a polymer prepared from more than one unsaturated monomer, the polymer including from about 4 to about 90 weight percent of acid-functional monomer(s), said polymer having a calculated glass transition temperature less than the decomposition temperature of the polymer, with   (b) a transition metal compound having an average particle size sufficiently small to react with the polymer at a temperature approximately equal to or below the glass transition temperature of said polymer for a time sufficient to produce a degree of reaction of said acid and metal, wherein said reaction product is capable of forming a film, wherein the transition metal compound has an average particle size less than 300 nm.   
     
     
         6 . The composition of  claim 5  wherein the transition metal compound has an average particle size of up to 100 nm. 
     
     
         7 . The composition of  claim 1  wherein the polymer is an acid-functional styrene/acrylic copolymer. 
     
     
         8 . The composition of  claim 1  wherein the glass transition temperature of the polymer is above room temperature, and wherein the transition metal compound reacts with the polymer at approximately room temperature. 
     
     
         9 . The composition of  claim 8  wherein the transition metal compound reacts with the polymer below room temperature. 
     
     
         10 . The composition of  claim 1 , wherein the polymer is an aqueous emulsion or dispersion and the transition metal compound is insoluble in water. 
     
     
         11 . The composition of  claim 11  wherein the transition metal compound is in the form of an aqueous dispersion.