US4859361A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing electroluminescent phosphors of improved brightness
Assignee: Osram Sylvania Inc
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Filing: 1989-01-17
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Granted: 1989-08-22
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Expires: 2009-01-17
Abstract
Abstract A process is disclosed for producing an electroluminescent phosphor which comprises blending a chloride flux, a copper source, and zinc sulfide to form a relatively uniform admixture, heating the admixture at a temperature of from about 1000° C. to about 1300° C. for about 2 to about 8 hours to convert at least a portion of the admixture to a crystalline material containing zinc sulfide, at least some chloride ions, and copper ions, washing the material with sufficient water to remove at least a major portion of the water soluble material from the crystalline material, drying the material to produce a relatively moisture-free material which is low intensity milled for a sufficient time to change the crystallographic structure of at least a portion of the moisture-free material, blending the milled material with zinc sulfate and copper sulfate, with or without manganese carbonate depending on whether manganese is desired as an activator, to form a second admixture, which is heated at a temperature of from about 750° C. to about 850° C. for about 1.5 to about 3 hours to form an activated material which is cooled for a period of time of from about 10 minutes to about 20 minutes followed by immediately quenching in water, removing the water from the cooled and quenched activated material, washing the material with reactive aqueous solutions to remove residual fluxes and excess activator materials, and drying the material to form an electroluminescent phosphor.
Inventors
- 👤 Kenneth T. Reilly
- 👤 Richard G. W. Gingerich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:10
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/61; C09K11/611; C09K11/612
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
263 words
A process for producing an electroluminescent phosphor comprising: (a) blending a chloride flux, a copper source, and zinc sulfide to form a relatively uniform admixture; (b) heating the resulting admixture at a temperature of from about 1000° C. to about 1300° C. for about 2 to about 8 hours to convert at least a portion of the admixture to a crystalline material containing zinc sulfide, at least some chloride ions, and copper ions, (c) washing the resulting material with sufficient water to remove at least a major portion of the water soluble material from the crystalline material; (d) drying the washed material to produce a relatively moisture-free material; (e) subjecting said relatively moisture-free material to low intensity milling for a sufficient time to change the crystallographic structure of at least a portion of the moisture-free material from a hexagonal structure to a cubic structure; (f) blending the resulting milled material with zinc sulfate and copper sulfate to form a second admixture; (g) heating said second admixture at a temperature of from about 750° C. to about 850° C. for about 1.5 to about 3 hours to form an activated material; (h) cooling said activated material by allowing it to stand at room temperature for a period of time of from about 10 minutes to about 20 minutes followed by immediately quenching said cooled material in water; (i) removing said water from the resulting cooled and quenched activated material; (j) washing said quenched activated material to remove residual fluxes and excess activator materials; (k) drying the resulting washed material to form an electroluminescent phosphor.
Claim 2
Dependent Claim
263 words
A process for producing an electroluminescent phosphor comprising: (a) blending a chloride flux, a copper source, and zinc sulfide to form a relatively uniform admixture; (b) heating the resulting admixture at a temperature of from about 1000° C. to about 1300° C. for about 2 to about 8 hours to convert at least a portion of the admixture to a crystalline material containing zinc sulfide, at least some chloride ions, and copper ions, (c) washing the resulting material with sufficient water to remove at least a major portion of the water soluble material from the crystalline material; (d) drying the washed material to produce a relatively moisture-free material; (e) subjecting said relatively moisture-free material to low intensity milling for a sufficient time to change the crystallographic structure of at least a portion of the moisture-free material from a hexagonal structure to a cubic structure; (f) blending the resulting milled material with zinc sulfate and copper sulfate to form a second admixture; (g) heating said second admixture at a temperature of from about 750° C. to about 850° C. for about 1.5 to about 3 hours to form an activated material; (h) cooling said activated material by allowing it to stand at room temperature for a period of time of from about 10 minutes to about 20 minutes followed by immediately quenching said cooled material in water; (i) removing said water from the resulting cooled and quenched activated material; (j) washing said quenched activated material to remove residual fluxes and excess activator materials; (k) drying the resulting washed material to form an electroluminescent phosphor.
Claim 3
Dependent Claim
20 words
A process of claim 1 wherein said quenched activated material is washed with acetic acid to remove unreacted zinc materials.
Claim 4
Dependent Claim
24 words
A process of claim 1 wherein said quenched activated material is washed with an aqueous solution of potassium cyanide to remove excess copper materials.
Claim 5
Dependent Claim
35 words
A process of claim 1 wherein the electroluminescent phosphor is classified to remove undesirable size material and to yield a material having a particle size of from about 15 to about 60 micrometers in diameter.
Claim 6
Dependent Claim
265 words
A process for producing an electroluminescent phosphor comprising: (a) blending a chloride flux, a copper source, and zinc sulfide to form a relatively uniform admixture; (b) heating the resulting admixture at a temperature of from about 1000° C. to about 1300° C. for about 2 to about 8 hours to convert at least a portion of the admixture to a crystalline material containing zinc sulfide, at least some chloride ions, and copper ions, (c) washing the resulting material with sufficient water to remove at least a major portion of the water soluble material from the crystalline material; (d) drying the washed material to produce a relatively moisture-free material; (e) subjecting said relatively moisture-free material to low intensity milling for a sufficient time to change the crystallographic structure of at least a portion of the moisture-free material from a hexagonal structure to a cubic structure; (f) blending the resulting milled material with zinc sulfate, copper sulfate, and manganese carbonate to form a second admixture; (g) heating said second admixture at a temperature of from about 750° C. to about 850° C. for about 1.5 to about 3 hours to form an activated material; (h) cooling said activated material by allowing it to stand at room temperature for a period of time of from about 10 minutes to about 20 minutes followed by immediately quenching said cooled material in water; (i) removing said water from the resulting cooled and quenched activated material; (j) washing said quenched activated material to remove residual fluxes and excess activator materials; (k) drying the resulting washed material to form an electroluminescent phosphor.
Claim 7
Dependent Claim
265 words
A process for producing an electroluminescent phosphor comprising: (a) blending a chloride flux, a copper source, and zinc sulfide to form a relatively uniform admixture; (b) heating the resulting admixture at a temperature of from about 1000° C. to about 1300° C. for about 2 to about 8 hours to convert at least a portion of the admixture to a crystalline material containing zinc sulfide, at least some chloride ions, and copper ions, (c) washing the resulting material with sufficient water to remove at least a major portion of the water soluble material from the crystalline material; (d) drying the washed material to produce a relatively moisture-free material; (e) subjecting said relatively moisture-free material to low intensity milling for a sufficient time to change the crystallographic structure of at least a portion of the moisture-free material from a hexagonal structure to a cubic structure; (f) blending the resulting milled material with zinc sulfate, copper sulfate, and manganese carbonate to form a second admixture; (g) heating said second admixture at a temperature of from about 750° C. to about 850° C. for about 1.5 to about 3 hours to form an activated material; (h) cooling said activated material by allowing it to stand at room temperature for a period of time of from about 10 minutes to about 20 minutes followed by immediately quenching said cooled material in water; (i) removing said water from the resulting cooled and quenched activated material; (j) washing said quenched activated material to remove residual fluxes and excess activator materials; (k) drying the resulting washed material to form an electroluminescent phosphor.
Claim 8
Dependent Claim
20 words
A process of claim 5 wherein said quenched activated material is washed with acetic acid to remove unreacted zinc materials.
Claim 9
Dependent Claim
24 words
A process of claim 5 wherein said quenched activated material is washed with an aqueous solution of potassium cyanide to remove excess copper materials.
Claim 10
Dependent Claim
20 words
A process of claim 5 wherein said quenched activated material is washed with hydrochloric acid to remove unreacted manganese materials.
Claim 11
Dependent Claim
39 words
A process of claim 5 wherein the electroluminescent phosphor is subjected to particle size classification to remove undesirable size material and to yield a material having a particle size of from about 15 to about 60 micrometers in diameter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-21 | 1993-02-20 | 1993-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-21 | 1997-02-20 | 1997-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-21 | 2001-02-20 | 2001-08-22 | $7700.00 | Window Closed / Lapsed |