Patent US3905911A successfully refreshed from Google Patents.
US3905911A
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Copper activated hafnium phosphate phosphors and method of making
Assignee: GTE Sylvania Inc
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Filing: 1974-09-25
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Granted: 1975-09-16
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Expires: 1994-09-25
Abstract
Abstract Disclosed are hafnium phosphate phosphors activated by copper and having the general formula Hf3(PO4)4: Cu wherein copper is present as about 0.005 to 25% by weight of the matrix. The phosphors are prepared by forming a mixture of suitable sources of hafnium, phosphate and copper and first firing for about 30 minutes in a closed crucible at about 800*C. The cake formed thereby is mortared or ground and refired for about 30 minutes in a mildly reducing atmosphere at 1100*C. The finished phosphor emits green under the ultraviolet and cathode ray excitation and x-ray.
Inventors
- 👤 Jr Paul V Kelsey
- 👤 James E Mathers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:36
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/70
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
45 words
A LUMINESCENT COMPOSITION OF MATTER HAVING A MATRIX OF HR3CPO)4 ACTIVATED BY COPPER CORRESPONDING TO THE FORMULA HF3(PO4)4:CU WHEREIN THE AMOUNT OF COPPER IS FROM ABOUT 0.005 TO 25% BY WEIGHT OF SAID MATRIX, SAID COMPOSITION LUMINESCING GREEN UNDER ULTRAVIOLET, CATHODE RAY OR X-RAY EXCITATION.
Claim 2
Dependent Claim
45 words
A LUMINESCENT COMPOSITION OF MATTER HAVING A MATRIX OF HR3CPO)4 ACTIVATED BY COPPER CORRESPONDING TO THE FORMULA HF3(PO4)4:CU WHEREIN THE AMOUNT OF COPPER IS FROM ABOUT 0.005 TO 25% BY WEIGHT OF SAID MATRIX, SAID COMPOSITION LUMINESCING GREEN UNDER ULTRAVIOLET, CATHODE RAY OR X-RAY EXCITATION.
Claim 3
Dependent Claim
21 words
The composition of claim 1 wherein said amount of copper is from about 0.01 to 5% by weight of said matrix.
Claim 4
Dependent Claim
72 words
A method of making the composition of claim 1 which comprises the steps of: mixing together appropriate amounts of a hafnium compound, a phosphate compound and a copper compound to form a mixture which yields said composition upon subsequent firing; firing said mixture in a closed crucible at about 800*C for about 30 minutes; and mortaring said mixture and refiring at about 1, 100*C for about 30 minutes in a steam atmosphere.
Claim 5
Dependent Claim
25 words
The method of claim 3 wherein said hafnium compound is HfOCl2; said phosphate compound is (NH4)2HPO4; and said copper compound is (CH3COO)2 Cu . H2O.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |