Method of preparing flake-like ceramic particle of zinc sulfide phosphor
First Claim
1. A method of preparing flake-like ceramic particles of zinc sulfide phosphor, which comprises the steps ofpreparing flake-like particles of basic zinc sulfate crystal doped with activator, by precipitating said basic zinc sulfate particles from an aqueous solution containing zinc sulfate, urea and an activator metal ion component which is at least one activator metal ion selected from the group consisting of copper, silver, gold, aluminum, indium, gallium, rare earth metal and manganese, the atomic ratio of said activator metal ion component in said aqueous solution being 10-5 to 10-2 with respect to the zinc atom of said zinc sulfate,sulfurizing said basic zinc sulfate particles in a carbon disulfide atmosphere at a temperature from 400°
- to 800°
C., andheating the thus sulfurized particles in a hydrogen sulfide atmosphere at a temperature from 800°
to 1200°
C.
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Abstract
Flake-like ceramic particles of zinc sulfide phosphor and method of preparing the same including the steps of preparing flake-like particles of basic zinc sulfate crystal doped with activator, sulfurizing in the particles carbon disulfide, and heating the sulfurized particles in hydrogen sulfide. Particularly by steeping said particles in a solution of alkaline earth metal salt prior to or after sulfurizing, grain growth in ceramic particles can be improved.
14 Citations
11 Claims
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1. A method of preparing flake-like ceramic particles of zinc sulfide phosphor, which comprises the steps of
preparing flake-like particles of basic zinc sulfate crystal doped with activator, by precipitating said basic zinc sulfate particles from an aqueous solution containing zinc sulfate, urea and an activator metal ion component which is at least one activator metal ion selected from the group consisting of copper, silver, gold, aluminum, indium, gallium, rare earth metal and manganese, the atomic ratio of said activator metal ion component in said aqueous solution being 10-5 to 10-2 with respect to the zinc atom of said zinc sulfate, sulfurizing said basic zinc sulfate particles in a carbon disulfide atmosphere at a temperature from 400° - to 800°
C., andheating the thus sulfurized particles in a hydrogen sulfide atmosphere at a temperature from 800°
to 1200°
C. - View Dependent Claims (2, 3, 4, 5, 6)
- to 800°
-
7. A method of preparing flake-like ceramic particles of zinc sulfide phosphor, which comprises the steps of
preparing flake-like particles of basic zinc sulfate crystal doped with activator, by precipitating said basic zinc sulfate particles from an aqueous solution containing zinc sulfate, urea and an activator metal ion component which is at least one activator metal ion selected from the group consisting of copper, silver, gold, aluminum, indium, gallium, rare earth metal and manganese, the atomic ratio of said activator metal ion component in said aqueous solution being 10-5 to 10-2 with respect to the zinc atom of said zinc sulfate, sulfurizing said basic zinc sulfate particles in a carbon disulfide atmosphere at a temperature from 400° - to 800°
C.,steeping the thus sulfurized particles in an aqueous solution of 0.001 to 2.0 mole per liter of at least one alkaline earth metal salt selected from the group consisting of carbonates, sulfates and halides of calcium, magnesium, strontium and barium, filtering and drying the thus treated particles, and heating the dried particles in a hydrogen sulfide atmosphere at a temperature from 800°
to 1200°
C. - View Dependent Claims (8, 9, 10, 11)
- to 800°
Specification