Patent ID: 6733826
Filing Date: 2004-05-11
Classification: C09K,Y10S

Abstract:
A process for preparing particles of zinc sulfide-based electroluminescent phosphor having a moisture resistant coating thereon comprising the steps of:selecting a reaction vessel having a given height and a porous disc at the bottom thereof; charging said reaction vessel with phosphor particles and fluidizing said particles by introducing an inert gas into said vessel through said porous disc; heating said reaction vessel to a reaction temperature; introducing a coating precursor into said reaction vessel at a position adjacent said bottom of said vessel but above said disc; introducing a co-reactant into said reaction vessel at a position substantially mid-way of said given height; and maintaining said inert gas flow, said precursor flow and said co-reactant flow for a time sufficient for a reaction to occur and coat said phosphor with said moisture resistant coating.