Electro immersion lacquer produced by melt emulsification

Abstract

Novel electrodeposition coating material preparable by (i) melting at least one self-crosslinking binder, or (ii) separately melting at least one externally crosslinking binder and at least one crosslinking agent and supplying the melts to a mixing unit in which the melts are homogenized, introducing the resultant melt into an aqueous medium, and emulsifying it therein; and the use of the novel electrodeposition coating material to coat electrically conductive substrates.

What is claimed is:  
     
         1 . An electrodeposition coating material preparable by (i) melting at least one self-crosslinking binder, or 
 (ii) separately melting at least one externally crosslinking binder and at least one crosslinking agent and supplying the melts to a mixing unit in which the melts are homogenized,    introducing the resultant melt into an aqueous medium, and emulsifying it therein.    
     
     
         2 . The coating material as claimed in  claim 1 , wherein the aqueous medium comprises at least one neutralizing agent.  
     
     
         3 . The coating material as claimed in  claim 2 , wherein the neutralizing agent is at least one acid.  
     
     
         4 . The coating material as claimed in any of  claims 1  to  3 , wherein the mixing unit is a static mixer.  
     
     
         5 . The coating material as claimed in any of  claims 1  to  4 , wherein the melt is emulsified in the aqueous medium in a static mixer, in a rotor-stator system or in a high-pressure homogenizer.  
     
     
         6 . The coating material as claimed in  claim 5 , wherein a high-pressure homogenizer is used which operates in accordance with the opposed-jet principle.  
     
     
         7 . The coating material as claimed in  claim 5 , wherein said rotor-stator system comprises a high-speed stirrer (Ultraturrax), a wet rotor mill, an in-line dissolver, or a toothed-wheel dispersing unit.  
     
     
         8 . The coating material as claimed in any of  claims 1  to  7 , wherein the discontinuous phase of the emulsion has an average droplet size of 40 to 1000 nm.  
     
     
         9 . The use of the coating material as claimed in any of  claims 1  to  8  to coat electrically conductive substrates.  
     
     
         10 . A process for coating electrically conductive substrates by electrophoretically depositing an electrodeposition coating material on the substrates and thermally curing the resultant electrodeposition coating film alone or together with at least one further coating film present thereon, which comprises using an electro-deposition coating material as claimed in any of  claims 1  to  8 .