Heat sensitive substrates coated with waterborne coating compositions

Abstract

The present invention is directed to a coated substrate comprising: A) a heat sensitive substrate having a heat distortion temperature less than 120 degrees C., and B) a coating layer deposited on at least one surface of the substrate, wherein the coating layer is deposited from a waterborne coating composition comprising: (a) a continuous phase comprising water, and (b) a dispersed phase comprising: (i) optional pigments; (ii) polymeric particles containing carboxylic acid functionality prepared from the polymerization of a mixture of ethylenically unsaturated compounds including ethylenically unsaturated monomers; and (iii) a polycarbodiimide or a polyhydrazide.

What is claimed is: 
     
         1 . A coated substrate comprising:
 A) a heat sensitive substrate having a heat distortion temperature less than 120 degrees C., and   B) a coating layer deposited on at least one surface of the substrate, wherein the coating layer is deposited from a waterborne coating composition comprising:   (a) a continuous phase comprising water, and   (b) a dispersed phase comprising:
 (i) optional pigments; 
 (ii) polymeric particles containing carboxylic acid functionality prepared from the polymerization of a mixture of ethylenically unsaturated compounds including ethylenically unsaturated monomers; and 
 (iii) a polycarbodiimide. 
   
     
     
         2 . The coated substrate of  claim 1 , wherein the substrate A) comprises an exterior automotive substrate. 
     
     
         3 . The coated substrate of  claim 1 , wherein the substrate A) comprises a plastic or a composite substrate. 
     
     
         4 . The coated substrate of  claim 3 , wherein the substrate A) comprises a composite substrate comprising a resinous matrix reinforced with fibers. 
     
     
         5 . The coated substrate of  claim 4 , wherein the resinous matrix comprises at least one of polypropylene, polybutylene terephthalate, polystyrene, polyaniline, polypyrrole, polyepoxide, poly(methyl methacrylate), polyurethane, and polycarbonate. 
     
     
         6 . The coated substrate of  claim 4 , wherein the fibers comprise at least one of stainless steel fibers, copper fibers, nickel fibers, silver fibers, aluminum fibers, glass fibers, and carbon fibers. 
     
     
         7 . The coated substrate of  claim 3 , wherein the automotive substrate is a body part with a primer coating layer applied thereto, and wherein the coating composition is applied directly to the primer coating layer on the automotive substrate. 
     
     
         8 . The coated substrate of  claim 1 , wherein automotive substrate is a body part selected from hoods, lids, fenders, door panels, roofs, and bumpers. 
     
     
         9 . The coated substrate of  claim 1 , further comprising one or more additional coating layers applied on top of the coating layer B). 
     
     
         10 . The coated substrate of  claim 1  wherein the equivalent ratio of carbodiimide functional groups to acid functional groups is from 0.5 to 1.5:1. 
     
     
         11 . A coated substrate comprising:
 A) a heat sensitive substrate having a heat distortion temperature less than 120 degrees C., and   B) a coating layer deposited on at least one surface of the substrate, wherein the coating layer is deposited from a waterborne coating composition comprising:   
       (a) a continuous phase comprising water, and 
       (b) a dispersed phase comprising:
 (i) pigments; 
 (ii) polymeric particles prepared from the polymerization of a mixture of ethylenically unsaturated compounds including ethylenically unsaturated monomers comprising from: 
 (A) 2 to 30 percent by weight of a multi-ethylenically unsaturated monomer and 
 (B) at least 30 percent by weight of an aldo or keto group-containing ethylenically unsaturated monomer, the percentages by weight being based on total weight of the ethylenically unsaturated monomers; and 
 (iii) a polyhydrazide. 
 
     
     
         12 . The coated substrate of  claim 11 , wherein the substrate A) comprises an exterior automotive substrate. 
     
     
         13 . The coated substrate of  claim 11 , wherein the substrate A) comprises a plastic or a composite substrate. 
     
     
         14 . The coated substrate of  claim 13 , wherein the substrate A) comprises a composite substrate comprising a resinous matrix reinforced with fibers. 
     
     
         15 . The coated substrate of  claim 14 , wherein the resinous matrix comprises at least one of polypropylene, polybutylene terephthalate, polystyrene, polyaniline, polypyrrole, polyepoxide, poly(methyl methacrylate), polyurethane, and polycarbonate. 
     
     
         16 . The coated substrate of  claim 14 , wherein the fibers comprise at least one of stainless steel fibers, copper fibers, nickel fibers, silver fibers, aluminum fibers, glass fibers, and carbon fibers. 
     
     
         17 . The coated substrate of  claim 13 , wherein the automotive substrate is a body part with a primer coating layer applied thereto, and wherein the coating composition is applied directly to the primer coating layer on the automotive substrate. 
     
     
         18 . The coated substrate of  claim 11 , wherein automotive substrate is a body part selected from hoods, lids, fenders, door panels, roofs, and bumpers. 
     
     
         19 . The coated substrate of  claim 11 , further comprising one or more additional coating layers applied on top of the coating layer B).