Metal effect pigments for use in the cathodic electrodeposition painting, method for the production and use of the same, and electrodeposition paint

Abstract

The invention relates to electrocoat material pigments, said electrocoat material pigments comprising metal effect pigment platelets coated with at least one coating material, said coating material comprising one or more functional groups for adhesion or attachment to the pigment surface and at least one amino-functional group, said amino-functional group being protonatable or positively charged. The invention further relates to a process for producing these electrocoat material pigments and to the use thereof, and to a cathodic electrocoat material which comprises the inventive pigments.

1 . An electrocoat material pigment,
 said electrocoat material pigment comprising metal effect pigment platelets coated with at least one coating material, said coating material comprising   a) one or more functional groups for adhesion or attachment to the pigment surface and   b) at least one amino-functional group, said amino-functional group being protonatable or positively charged.   
   
   
       2 . The electrocoat material pigment as claimed in  claim 1 ,
 wherein   the metal effect pigments have a coating which inhibits corrosion by aqueous systems or media.   
   
   
       3 . The electrocoat material pigment as claimed in  claim 1 ,
 wherein   the metal effect pigments are selected from the group comprising metal effect pigments provided with at least one of inorganic and organic coatings, metal effect pigments provided with inorganic/organic mixed layers, metal effect pigments coated with synthetic resin, surface-oxidized metal effect pigments and colored metal effect pigments.   
   
   
       4 . The electrocoat material pigment as claimed in  claim 1 ,
 wherein   the metal effect pigment platelets consist of metals or alloys which are selected from the group consisting of aluminum, copper, zinc, tin, brass, iron, titanium, chromium, nickel, steel, silver and alloys and mixtures thereof.   
   
   
       5 . The electrocoat material pigment as claimed in  claim 3 ,
 wherein   the synthetic resin coating of the metal effect pigment comprises at least one of a polyacrylate, a polymethacrylate and a combination thereof.   
   
   
       6 . The electrocoat material pigment as claimed in  claim 2 ,
 wherein   the corrosion-inhibiting coating consists essentially of a metal oxide.   
   
   
       7 . The electrocoat material pigment as claimed in  claim 2 ,
 wherein   the corrosion-inhibiting coating is a surface oxide layer.   
   
   
       8 . The electrocoat material pigment as claimed in  claim 6   wherein   the oxide layer additionally comprises color pigments.   
   
   
       9 . The electrocoat material pigment as claimed  claim 1 ,
 wherein   the coating material has one or more functional groups for adhesion or attachment to the metal effect pigment surface or to at least one of a synthetic resin surface and an inorganic coating applied to the metal effect pigment surface.   
   
   
       10 . The electrocoat material pigment as claimed in  claim 9 ,
 wherein   one or more functional groups of the coating material are selected from the group consisting of phosphonic ester, phosphoric ester, carboxylate, metallic ester, alkoxysilyl, silanol, sulfonate, hydroxyl, polyol groups and mixtures thereof.   
   
   
       11 . The electrocoat material pigment as claimed in  claim 1 ,
 wherein   the coating material is applied to the pigment in an amount of 1 to 100% by weight based on the weight of the metallic component of the metal effect pigment.   
   
   
       12 . The electrocoat material pigment as claimed in  claim 1 ,
 wherein   the coating material is a cathodic electrocoat material binder.   
   
   
       13 . A process for producing electrocoat material pigments as claimed in  claim 1 ,
 wherein   the process comprises the following steps:
 (a) coating a metal effect pigment with the coating material having an amino-functional group dissolved or dispersed in a solvent, said amino-functional group being protonatable or positively charged, 
 (b) optionally drying the metal effect pigments coated with the coating material in step (a), and 
 (c) optionally converting the metal effect pigments dried in step (b) to a paste. 
   
   
   
       14 . The process as claimed in  claim 13 ,
 wherein   steps (a) and (b) are combined into a single step, by applying the coating material as a solution or dispersion to metal effect pigments moving in a gas stream.   
   
   
       15 . A method of making a cathodic electrocoat material for use in cathodic electrocoating, said method comprising incorporating into said cathodic electrocoat material a plurality of electrocoat material pigments as claimed in  claim 1 . 
   
   
       16 . A cathodic electrocoat material comprising electrocoat material pigments as claimed in  claim 1 . 
   
   
       17 . The electrocoat material pigment as claimed in  claim 6 , wherein the metal oxide is silicon dioxide.