Copper-based metal flakes, in particular comprising aluminum, and method for production thereof

Abstract

The present invention relates to highly lustrous gold-colored metal effect pigments comprising a copper-based alloy and additional metallic alloy components, preferably aluminum, and which are produced by means of stripping and comminuting metal films deposited in vacuo.

1 . Lustrous copper-based metal flakes that contain, in addition to copper, at least one additional metallic alloy component and are produced via vacuum deposition of metal films onto a carrier sheet, stripping of the films from the carrier sheet, and subsequent comminuting of the films.  
     
     
         2 . Lustrous copper-based metal flakes according to  claim 1 , characterized in that the flakes contain at least 51% copper and between 1 and 49% aluminum.  
     
     
         3 . Lustrous copper-based metal flakes according to  claim 1 , characterized in that the flakes contain silicon as an additional alloy component.  
     
     
         4 . Lustrous copper-based metal flakes according to  claim 1 , characterized in that the flake-shaped effect pigment has plane-parallel surfaces and a thickness between 10 and 100 nm, preferably between 20 and 60 nm.  
     
     
         5 . Lustrous, copper-based metal flakes according to  claim 1 , characterized in that the surface of the pigment particles is coated with an anticorrosive layer.  
     
     
         6 . Lustrous copper-based metal flakes according to  claim 5 , characterized in that the anticorrosive layer contains aluminum oxide, silicon oxide, phosphate, phosphoric acid, phosphoric ester, phosphinic acid, silanes, organically modified silicates, titanates, zirconates or methacrylate-based polymer layers or combinations of these compounds.  
     
     
         7 . A method for producing lustrous, copper-based metal flakes according to  claim 1  with the following process steps: 
 a) optionally applying a release coat on a carrier sheet;    b) applying of a metal film onto the release coat or the carrier sheet;    c) stripping of the metal film; and    d) comminuting to pigment particles.    
     
     
         8 . A method according to  claim 7 , characterized in that applying of the metal film takes place through evaporation of the alloy components.  
     
     
         9 . A method according to  claim 7 , characterized in that applying of the metal film takes place through separate evaporation of the alloy components.  
     
     
         10 . A method according to  claim 7 , characterized in that applying of the metal film takes place through separate evaporation of an alloy and one or more additional components.  
     
     
         11 . A method according to  claim 7 , characterized in that applying of the metal film takes place through electron beam, resistance heating, or radiation heating.  
     
     
         12 . A method according to  claim 7 , characterized in that applying of the metal film takes places through flash evaporation, simultaneous evaporation, or jumping beam evaporation.