Conductive flakes manufactured by combined sputtering and vapor deposition

Abstract

A release agent is flash evaporated and deposited onto a support substrate under conventional vapor-deposition conditions and a conductive metal oxide, such as ITO, is subsequently sputtered or deposited by reactive electron beam onto the resulting release layer in the same process chamber to form a very thin film of conductive material. The resulting multilayer product is separated from the support substrate, crushed to brake up the metal-oxide film into flakes, and heated or mixed in a solvent to separate the soluble release layer from the metallic flakes. Thus, by judiciously controlling the deposition of the ITO on the release layer, transparent flakes may be obtained with the desired optical and physical characteristics.

What is claimed is:  
     
         1 . A process for producing flakes of a conductive material, comprising the following steps: 
 (a) flash evaporating a release material in a vacuum chamber to produce a vapor;    (b) cryocondensing the vapor to produce a solid film of said release material;    (c) sputtering or reactive electron-beam depositing a conductive-material precursor to form a layer thereof on said film of release material;    (d) crushing said layer of conductive-material precursor to produce conductive flakes; and    (e) isolating said conductive flakes from the release material.    
     
     
         2 . The process of  claim 1 , wherein said steps (a) and (c) are both carried out in said vacuum chamber.  
     
     
         3 . The process of  claim 2 , wherein said steps (a)-(c) are carried out continuously over a rotating drum.  
     
     
         4 . The process of  claim 2 , wherein said steps (a)-(c) are carried out continuously over a web in contact with a rotating drum.  
     
     
         5 . The process of  claim 1 , wherein said conductive-material precursor is selected from the group consisting of metal oxides, gold, palladium, platinum, nickel, silver, and copper.  
     
     
         6 . The process of  claim 2 , wherein said conductive-material precursor is selected from the group consisting of metal oxides, gold, palladium, platinum, nickel, silver and copper.  
     
     
         7 . The process of  claim 1 , wherein said release material is selected from the group consisting of polyethylene oligomers, poly(α-methylstyrene) oligomers, polycycloaliphatic oligomers, fluorocarbon oligomers, and silicone-based oligomer.  
     
     
         8 . The process of  claim 2 , wherein said release material is selected from the group consisting of polyethylene oligomers, poly(α-methylstyrene) oligomers, polycycloaliphatic oligomers, fluorocarbon oligomers, and silicone-based oligomer.  
     
     
         9 . A conductive flake produced by the process of  claim 1 .  
     
     
         10 . A conductive flake produced by the process of  claim 3 .  
     
     
         11 . A conductive flake produced by the process of  claim 4 .  
     
     
         12 . A conductive flake produced by the process of  claim 5 .  
     
     
         13 . A process for manufacturing a conductive ink for coating a clear surface and produce a clear conductive surface, comprising the following steps: 
 (a) flash evaporating a release material in a vacuum chamber to produce a vapor;    (b) cryocondensing the vapor to produce a solid film of said release material;    (c) sputtering or reactive electron-beam depositing a conductive-material precursor to form a layer thereof on said film of release material;    (d) crushing said layer of conductive-material precursor to produce conductive flakes; and    (e) isolating said conductive flakes from the release material: and    (f) dispersing the conductive flakes produced in step (e) in a binder to produce a conductive ink.    
     
     
         14 . The process of  claim 13 , wherein said steps (a) and (c) are both carried out in said vacuum chamber.  
     
     
         15 . The process of  claim 13 , wherein said steps (a)-(c) are carried out continuously over a rotating drum.  
     
     
         16 . The process of  claim 13 , wherein said steps (a)-(c) are carried out continuously over a web in contact with a rotating drum.  
     
     
         17 . The process of  claim 13 , wherein said conductive-material precursor is selected from the group consisting of metal oxides, gold, palladium, platinum, nickel, silver and copper.  
     
     
         18 . The process of  claim 14 , wherein said conductive-material precursor is selected from the group consisting of metal oxides, gold, palladium, platinum, nickel, silver and copper.  
     
     
         19 . The process of  claim 13 , wherein said release material is selected from the group consisting of polyethylene oligomers, poly(α-methylstyrene) oligomers, polycycloaliphatic oligomers, fluorocarbon oligomers, and silicone-based oligomers.  
     
     
         20 . The process of  claim 14 , wherein said release material is selected from the group consisting of polyethylene oligomers, poly(α-methylstyrene) oligomers, polycycloaliphatic oligomers, fluorocarbon oligomers, and silicone-based oligomers.  
     
     
         21 . A conductive ink produced by the process of  claim 13 .  
     
     
         22 . A conductive ink produced by the process of  claim 14 .  
     
     
         23 . A conductive ink produced by the process of  claim 15 .  
     
     
         24 . A conductive ink produced by the process of  claim 16 .  
     
     
         25 . Apparatus for producing a multi-layer body of a crushable conductive-material precursor film sandwiched between layers of release material, comprising: 
 (a) means for flash evaporating the release material in a vacuum chamber to produce a vapor thereof;    (b) means for cryocondensing the vapor to produce a solid film of said release material in said vacuum chamber; and    (c) sputtering means or reactive electron-beam-deposition means contained in said vacuum chamber for depositing the conductive-material precursor to form a layer thereof on said film of release material.