Patent ID: 6398999
Filing Date: 2002-06-04
Classification: B22F,B82Y,C01P,C09C,C09D,C23C

Abstract:
A process for making metal flakes comprising:providing a vacuum deposition chamber containing a deposition surface; providing a release coat source and a metal deposition source in the vacuum deposition chamber, each directed toward the deposition surface; depositing on the deposition surface under vacuum in alternating layers a vaporized polymeric release coat layer from the release coat source and a vapor deposited metal layer from the metal deposition source to build up in sequence a multi-layer vapor deposit of metal layers separated by and deposited on corresponding intervening release coat layers; the release coat layers comprising a thermoplastic polymeric material which was vaporized under vacuum to form a smooth continuous barrier layer and support surface on which each of the metal layers is formed, the vapor deposited thermoplastic polymeric release coat layer dissolvable in an organic solvent; the metal layers comprising vapor-deposited metal in elemental form deposited to a film thickness of less than about 400 Angstroms; and removing the multi-layer vapor deposit from the vacuum deposition chamber and separating it into metal flakes by treatment with an organic solvent which dissolves the release coat layers and yields single layer metal flakes which are essentially free of the release coat material.