Sulfur-containing phosphor powders, methods for making phosphor powders and devices incorporating same
AssigneeCabot Corporation
InventorsMark J. Hampden-Smith, Toivo T. Kodas, James Caruso, Daniel J. Skamser, Quint H. Powell, Klaus Kunze
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Abstract
Sulfur-containing phosphor powders, methods for making phosphor powders and devices incorporating same. The powders have a small particle size, narrow particle size distribution and are substantially spherical. The method of the invention permits the continuous production of such powders. The invention also relates to products such as display devices incorporating such phosphor powders.
Claims36
A method for securing a document comprising the step of applying a phosphor powder to said document, wherein the phosphor powder comprises sulfur-containing phosphor particles that are substantially spherical and have an average particle size of from about 0.3 μm to not greater than 10 μm.
A security document comprising a phosphor powder, the phosphor powder comprising sulfur-containing phosphor particles that are substantially spherical and have an average particle size of from about 0.3 μm to not greater than 10 μm.
A taggant comprising a metal sulfide phosphor powder, the phosphor powder comprising phosphor particles that are substantially spherical and have an average particle size of from about 0.3 μm to not greater than 10 μm and that emit characteristic wavelengths in the ultraviolet spectrum.
An ink comprising metal sulfide phosphor particles that are substantially spherical and having an average particle size from about 0.3 μm to not greater than 10 μm, and a liquid vehicle.
A taggant comprising a metal sulfide phosphor powder, the phosphor powder comprising phosphor particles that are substantially spherical and have an average particle size of from about 0.3 μm to not greater than 10 μm, wherein said metal sulfide phosphor is selected from the group consisting of SrS and CaS.
A security document comprising a taggant, wherein the taggant comprises a metal sulfide phosphor powder, the phosphor powder comprising phosphor particles that are substantially spherical and have an average particle size of from about 0.3 μm to not greater than 10 μm.
Currency comprising a taggant, wherein the taggant comprises a metal sulfide phosphor powder, the phosphor powder comprising phosphor particles that are substantially spherical and have an average particle size of from about 0.3 μm to not greater than 10 μm.
Dependencies are inferred from the claim text.