Method of coating a substrate including a simultaneous cure

Abstract

A method of coating a substrate includes the steps of applying an electrocoat to the substrate, applying a powder primer onto the electrocoat, and then applying a topcoat onto the powder primer. The topcoat typically includes a powder basecoat and a clearcoat. The powder primer is applied to the electrocoat without first curing the electrocoat before application of the powder primer. The powder basecoat is applied to the powder primer without first curing the powder primer before application of the powder basecoat. The clearcoat is applied over the powder basecoat after which the electrocoat, the powder primer, the powder basecoat, and the clearcoat are simultaneously cured in an oven.

1 . A method of coating a substrate with an electrocoat, a powder primer, and a topcoat, said method comprising the steps of:
 applying the electrocoat onto the substrate;   applying the powder primer onto the electrocoat;   applying the topcoat onto the powder primer; and   simultaneously curing the electrocoat, the powder primer, and the topcoat in an oven by application of heat.   
   
   
       2 . A method as set forth in  claim 1  wherein the step of simultaneously curing the electrocoat, the powder primer, and the topcoat is further defined as simultaneously curing the electrocoat, the powder primer, and the topcoat at a temperature between the range of 150° C. and 180° C. for a time between the range of 15 minutes and 30 minutes. 
   
   
       3 . A method as set forth in  claim 1  further comprising the step of dehydrating the electrocoat. 
   
   
       4 . A method as set forth in  claim 3  wherein the step of dehydrating the electrocoat is further defined as dehydrating the electrocoat at a temperature of 100° C. for a time of 10 minutes. 
   
   
       5 . A method as set forth in  claim 1  wherein the topcoat includes a basecoat and the step of applying the topcoat is further defined as applying the basecoat onto the powder primer. 
   
   
       6 . A method as set forth in  claim 5  wherein the basecoat includes a powder basecoat and the step of applying the basecoat is further defined as applying the powder basecoat onto the powder primer. 
   
   
       7 . A method as set forth in  claim 6  wherein the powder basecoat comprises a flake additive and the step of applying the powder basecoat is further defined as applying the powder basecoat comprising the flake additive onto the powder primer. 
   
   
       8 . A method as set forth in  claim 7  wherein the flake additive comprises at least one of a mica flake and a metal flake. 
   
   
       9 . A method as set forth in  claim 6  wherein the step of simultaneously curing the electrocoat, the powder primer and the topcoat is further defined as simultaneously curing the electrocoat, the powder primer, and the powder basecoat in an oven by application of heat. 
   
   
       10 . A method as set forth in  claim 6  wherein the step of applying the powder basecoat comprises a polyurethane. 
   
   
       11 . A method as set forth in  claim 6  wherein the step of applying the powder basecoat is further defined as applying the powder basecoat having a film build between the range of 40 microns and 50 microns. 
   
   
       12 . A method as set forth in  claim 11  wherein the step of applying the powder primer is further defined as applying the powder primer having a film build between the range of 30 microns and 40 microns. 
   
   
       13 . A method as set forth in  claim 5  wherein the basecoat includes a liquid basecoat and the step of applying the basecoat is further defined as applying the liquid basecoat onto the powder primer. 
   
   
       14 . A method as set forth in  claim 13  wherein the step of simultaneously curing the electrocoat, the powder primer and the topcoat is further defined as simultaneously curing the electrocoat, the powder primer, and the liquid basecoat in an oven by application of heat. 
   
   
       15 . A method as set forth in  claim 13  wherein the liquid basecoat comprises a polyurethane. 
   
   
       16 . A method as set forth in  claim 13  wherein the step of applying the liquid basecoat is further defined as applying the liquid basecoat having a film build between the range of 20 microns and 25 microns. 
   
   
       17 . A method as set forth in  claim 1  wherein the topcoat includes a clearcoat and the step of applying the topcoat is further defined as applying the clearcoat onto the powder primer. 
   
   
       18 . A method as set forth in  claim 17  wherein the step of applying the clearcoat is further defined as applying a powder clearcoat. 
   
   
       19 . A method as set forth in  claim 17  wherein the step of applying the clearcoat is further defined as applying a liquid clearcoat. 
   
   
       20 . A method as set forth in  claim 17  wherein the step of applying the clearcoat is further defined as applying the clearcoat having a film build between the range of 40 microns and 50 microns. 
   
   
       21 . A method as set forth in  claim 17  wherein the step of simultaneously curing the electrocoat, the powder primer and the topcoat is further defined as simultaneously curing the electrocoat, the powder primer, and the clearcoat in an oven by application of heat. 
   
   
       22 . A method as set forth in  claim 17  wherein the clearcoat comprises a resin selected from the group of acrylic polymers, polyester polymers, polyurethane polymers, and combinations thereof. 
   
   
       23 . A method as set forth in  claim 1  wherein the powder primer comprises a polyurethane. 
   
   
       24 . A method as set forth in  claim 1  wherein the topcoat includes a basecoat and a clearcoat and the step of simultaneously curing the electrocoat, the powder primer, and the topcoat is further defined as simultaneously curing the electrocoat, the powder primer, the basecoat, and the clearcoat in an oven by application of heat. 
   
   
       25 . A method as set forth in  claim 1  further comprising the step of applying a clearcoat onto the topcoat after simultaneously curing the electrocoat, the powder primer, and the topcoat. 
   
   
       26 . A method as set forth in  claim 25  further comprising the step of curing the clearcoat in an oven by application of heat.