A process for making functional or decorative flakes or platelets
economically and at high production rates comprises applying a multi-layer
sandwich of vapor deposited metal and release coats in alternating layers
to a rotating chilled drum or suitable carrier medium contained in a vapor
deposition chamber. The alternating metallized layers are applied by vapor
deposition and the intervening release layers are preferably solvent
soluble thermoplastic polymeric materials applied by vapor deposition
sources contained in the vapor deposition chamber. The multi-layer
sandwich built up in the vacuum chamber is removed from the drum or
carrier and treated with a suitable organic solvent to dissolve the
release coating from the metal in a stripping process that leaves the
metal flakes essentially release coat free. The solvent and dissolved
release material are then removed by centrifuging to produce a cake of
concentrated flakes which can be air milled and let down in a preferred
vehicle and further sized and homogenized for final use in inks, paints or
coatings. In one embodiment the finished flakes comprise single-layer thin
metal or metal alloy flakes or flakes of inorganic materials, and in
another embodiment flakes are coated on both sides with protective
polymeric coatings that were applied from suitable vacuum deposition
sources or the like contained in the vapor deposition chamber.
