Claims
- 1. A method for treating red emitting alkaline earth sulfide phosphor particles to provide moisture resistance which comprisesa) dispersing said phosphor particles in an anhydrous polar organic solvent containing a fluorinating agent at a concentration of about 0.01 molar or less, b) stirring said dispersion for a time sufficient to form a moisture impervious fluorinated coating on the phosphor particles, and c) removing the solvent and excess fluorinating agent.
- 2. A method according to claim 1 wherein the concentration of the fluorinating compound is 0.001 molar or less.
- 3. A method according to claim 1 wherein said alkaline earth sulfide is selected from the group consisting of calcium, strontium and barium sulfides.
- 4. A method according to claim 1 wherein said solvent is selected from the group consisting of alcohols having the formula ROH wherein R is an alkyl or alkenyl group of up to eight carbon atoms.
- 5. A method according to claim 4 wherein R is methyl.
- 6. A method according to claim 4 wherein R is ethyl.
- 7. A method according to claim 1 wherein after coating the phosphor particles with the fluorinating agent, the particles are washed with additional anhydrous polar solvent.
- 8. A method according to claim 1 wherein the fluorinating agent is a compound selected from the group consisting of ammonium fluoride, ammonium difluoride and ammonium fluorosilicate.
- 9. A method according to claim 1 wherein after a fluoride coating has been applied to the phosphor particles, a transparent organic polymer coating is applied thereover.
- 10. A method according to claim 9 wherein said transparent organic polymer coating is an acrylate-containing polymer.
- 11. A red emitting alkaline earth sulfide phosphor particle having an adherent, transparent fluorine-containing coating thereover and a second coating of a transparent organic polymer.
- 12. A phosphor particle according to claim 11 wherein said alkaline earth sulfide is selected from the group consisting of calcium sulfide, strontium sulfide and barium sulfide.
- 13. A phosphor particle according to claim 11 wherein said second organic polymer coating is an acrylate-containing polymer.
Parent Case Info
This application claims the benefit of U.S. provisional Application Ser. No. 60/104,368 filed Oct. 15, 1998.
US Referenced Citations (16)
Non-Patent Literature Citations (1)
Entry |
International Search Report for International PCT Applications No. PCT/US99/23927 dated Feb. 10, 2000. |
Provisional Applications (1)
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Number |
Date |
Country |
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60/104368 |
Oct 1998 |
US |