Multilayer coatings for metal substrates

Abstract

A multilayered coating ( 10 ) that is applied to a metal substrate ( 12 ). The coating comprises a protective zone of an insoluble crystalline phosphate formed by reaction of the substrate ( 12 ) with zinc phosphate. A film ( 16 ) of a polymer resin is deposited on the insoluble crystalline phosphate zone ( 14 ). In one embodiment, the multilayered coating ( 10 ) includes a coat of paint ( 18 ) that is applied to the polymer resin ( 16 ). A process for applying the multilayered coating to the metal substrate includes the steps of: applying a zinc phosphating solution to at least a portion of the substrate, which converts the surface to a zone of an insoluble crystalline phosphate; rinsing the zone; and autodepositing a film of a polymer resin thereupon.

What is claimed is:  
     
         1 . A multilayered coating that is applied to a metal substrate, comprising: 
 a protective zone of an insoluble crystalline phosphate formed by reaction of the substrate with a zinc phosphating solution disposed upon at least a portion of the substrate; and    a film of a polymer resin that is autodeposited on the crystalline phosphate.    
     
     
         2 . The multilayered coating of  claim 1 , further including a coat of paint applied to the polymer resin.  
     
     
         3 . The multilayered coating of  claim 1 , further including a paint pigment contained within the polymer resin.  
     
     
         4 . The multilayered coating of  claim 1 , wherein the polymer resin is autodeposited.  
     
     
         5 . The multilayered coating of  claim 2 , wherein the coat of paint is applied by a method selected from the group of steps consisting of electrodepositing, spraying, rolling, brushing, powder painting, and combinations thereof.  
     
     
         6 . The multilayered coating of  claim 2 , wherein the polymer resin is selected from the group consisting of an epoxy, an acrylic, polyvinylidine chloride, copolymers, and mixtures thereof.  
     
     
         7 . A coating that is applied to a metal substrate, comprising: 
 a film of a polymer resin applied to the substrate, the substrate including aluminum, the polymer resin-covered aluminum substrate having the characteristics of adherence between the polymer resin and the substrate, and corrosion resistance.    
     
     
         8 . A process for applying a multilayered coating to a metal substrate, comprising the steps of: 
 applying a zinc phosphating solution to at least a portion of the substrate, the zinc phosphating solution converting the surface of the substrate to an integral, protective zone of an insoluble crystalline phosphate;    rinsing the zone of crystalline phosphate; and    autodepositing a film of a polymer resin upon the rinsed crystalline phosphate.    
     
     
         9 . The process of  claim 8 , further comprising a curing step.  
     
     
         10 . The process of  claim 8 , further comprising the steps of: 
 post-rinsing the film of a polymer resin; and    electrodepositing a coat of paint upon the film of post-rinsed polymer resin.    
     
     
         11 . The process of  claim 10  further comprising the step of: 
 curing the autodeposited film of a polymer resin and the electrodeposited paint.  
 
     
     
         12 . The process of  claim 10  further comprising the steps of: 
 applying a number of coats of paint upon the electrodeposited coat of paint, wherein the number lies between zero and two; and  
 applying a clear-coat.  
 
     
     
         13 . A process for applying a multilayered coating to a metal substrate, comprising the steps of: 
 rinsing the substrate;    autodepositing a film of a polymer resin upon the rinsed substrate;    rinsing; and    curing the autodeposited film of a polymer resin.    
     
     
         14 . The multilayered coating of  claim 2 , wherein the polymer resin comprises a latex.