Waterborne film-forming compositions containing reactive surfactants and/or humectants

Abstract

The present invention is directed to aqueous coating compositions, such as paints, containing a film-forming latex polymer and a reactive surfactant and/or a low VOC humectant. The reactive surfactant, a polyglycerol ester or ether of an unsaturated fatty acid, reduces or eliminates the need for traditional water-soluble additives that lower the water resistance of the dry coating. Additionally, the reactive surfactants of the invention are capable of oxidative cross-linking during the curing process, forming a dry film that is more durable and water-resistant than traditional latex paint composition. The low VOC humectant polyglycerol, isosorbide, or a derivative of isosorbide can replace at least in part traditional humectants such as propylene glycol which contribute to VOCs, while maintaining an effective open time for application of the aqueous coating compositions.

1 . An aqueous coating composition comprising:
 (a) one or more film-forming latex polymers, and   (b) a humectant comprising one or more of isosorbide or a derivative thereof.   
     
     
         2 . The composition of  claim 1 , wherein the isosorbide or a derivative thereof is present in an amount effective to achieve an open time of about 5 to about 30 minutes when the composition is applied to a substrate. 
     
     
         3 . The composition of  claim 1 , wherein the humectant is selected from the group consisting of isosorbide, dimethyl isosorbide, diacetyl isosorbide, and mixtures thereof. 
     
     
         4 . The composition of  claim 1 , further comprising one or more additives, fillers, dispersants, surfactants, thickeners, solvents, bases, defoamers, biocides, or pigments. 
     
     
         5 . A method of coating a substrate, comprising providing the aqueous coating composition of  claim 1  and applying the composition to the substrate. 
     
     
         6 . A substrate having the composition of  claim 1  applied thereto. 
     
     
         7 . An article of manufacture comprising the coated substrate of  claim 6 . 
     
     
         8 . A method for extending the open time of an aqueous coating composition, comprising:
 (a) forming an aqueous coating composition comprising at least one film-forming latex polymer; and   (b) combining with the coating composition a humectant selected from the group consisting of:
 (i) one or more polyglycerols; and 
 (ii) one or more of isosorbide or a derivative thereof, 
 in an amount effective to extend the open time of the coating composition. 
   
     
     
         9 . The method of  claim 8 , wherein the open time of the composition is from about 5 minutes to about 30 minutes, suitably from about 5 to about 15 minutes. 
     
     
         10 . The method of  claim 8 , wherein the open time of the composition is from about 5 minutes to about 15 minutes. 
     
     
         11 . A method for reducing the VOC content of an aqueous coating composition comprising one or more film-forming latex polymers and a humectant without substantially reducing open time of the composition when applied to a substrate, comprising combining the one or more film-forming latex polymers used in the aqueous coating composition with a humectant selected from the group consisting of:
 (i) one or more polyglycerols; and   (ii) one or more of isosorbide or a derivative thereof.