Method of forming an electrocoating film, electrocoating film, and electrodeposited article

Abstract

The present invention has for its object to provide a method of forming an electrocoating film having an excellent smoothness and exceptionally high dielectric properties with a drastically reduced incidence of pinhole formation, such an electrocoating film, and such an electrodeposited article. A method of forming an electrocoating film comprising coating a work with an electrocoating composition curable by heating and irradiation with an activation energy beam in which an electrodepositing step, an aqueous cleaning step, a pre-baking step, an activation energy beam irradiation step, and a post-baking step are serially carried out in the order mentioned.

1 . A method of forming an electrocoating film comprising coating a work with an electrocoating composition curable by heating and irradiation with an activation energy beam 
 in which an electrodepositing step, an aqueous cleaning step, a pre-baking step, an activation energy beam irradiation step, and a post-baking step are serially carried out in the order mentioned.    
   
   
       2 . The method of forming an electrocoating film according to  claim 1 , wherein said activation energy beam irradiation step is carried out directly following said pre-baking step without cooling the work.  
   
   
       3 . The method of forming an electrocoating film according to  claim 1 , 
 wherein the heating in said post-baking step is continuous from said pre-baking step.    
   
   
       4 . The method of forming an electrocoating film according to  claim 1 , 
 wherein said electrocoating composition comprises a resin composition containing sulfonium and propargyl groups.    
   
   
       5 . The method of forming an electrocoating film according to  claim 1 , 
 wherein said electrocoating composition is a cationic electrocoating composition.    
   
   
       6 . An electrocoating film 
 which is formed by the method of forming an electrocoating film according to  claim 1 .    
   
   
       7 . An electrodeposited article having the electrocoating film according to  claim 6 .  
   
   
       8 . A method of forming a multilayer film 
 in which the electrocoating film according to  claim 6  is further coated with an overcoat.    
   
   
       9 . A multilayer film 
 which is formed by the method of forming a multilayer film according to  claim 8 .    
   
   
       10 . An article having the multilayer film according to  claim 9 .  
   
   
       11 . The method of forming an electrocoating film according to  claim 2 , wherein the heating in said post-baking step is continuous from said pre-baking step.  
   
   
       12 . The method of forming an electrocoating film according to  claim 2 , 
 wherein said electrocoating composition comprises a resin composition containing sulfonium and propargyl groups.    
   
   
       13 . The method of forming an electrocoating film according to  claim 3 , 
 wherein said electrocoating composition comprises a resin composition containing sulfonium and propargyl groups.    
   
   
       14 . The method of forming an electrocoating film according to claims  2 , 
 wherein said electrocoating composition is a cationic electrocoating composition.    
   
   
       15 . The method of forming an electrocoating film according to  claim 3 , 
 wherein said electrocoating composition is a cationic electrocoating composition.    
   
   
       16 . The method of forming an electrocoating film according to  claim 4 , 
 wherein said electrocoating composition is a cationic electrocoating composition.    
   
   
       17 . An electrocoating film 
 which is formed by the method of forming an electrocoating film according to  claim 2 .    
   
   
       18 . An electrocoating film 
 which is formed by the method of forming an electrocoating film according to  claim 3 .    
   
   
       19 . An electrocoating film 
 which is formed by the method of forming an electrocoating film according to  claim 4 .    
   
   
       20 . An electrocoating film 
 which is formed by the method of forming an electrocoating film according to  claim 5.