Method of preparing zinc sulfide phosphor coactivated with copper and gold
Patent 4208299 Issued on June 17, 1980. Estimated Expiration Date: 
January 31, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
January 31, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2623858 2956028 3922233 Method for producing cadmium free green emitting cathodoluminescent phosphor Color television cathode ray tube Patent #: 4151442 InventorsAssigneeApplicationNo. 05/873957 filed on 01/31/1978US Classes:252/301.6SSulfur containingExaminersPrimary: Cooper, JackAttorney, Agent or FirmInternational ClassesC09K 11/64 (20060101)H01J 29/32 (20060101) H01J 29/18 (20060101) Foreign Application Priority Data1977-01-31 JPAbstractA zinc sulfide phosphor having no segregated free sulfides of copper and gold on the surface layer thereof, which contains 0.003 to 0.03% by weight of copper and 0.01 to 0.2% by weight of gold as co-activators and further 0.0025 to 0.04% by weight of aluminum each on the basis of the zinc sulfide. The chromaticity of the emission from the phosphor is in the range of x=0.310 to 0.350 and y=0.560 to 0.600 on CIE chromaticity coordinates.A method for the preparation of this zinc sulfide phosphor which comprises adding aluminum fluoride as the aluminum ion source and ammonium iodide as the flux compound to powdery raw material for phosphor composed of zinc sulfide and the activator compounds, and firing the formed mixture in a reducing sulfurous atmosphere, thereby removing any segregated free sulfides of copper and gold.Other References
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