US3575876A
Expired / Lapsed
US
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Wet process for preparing antimony activated alkaline earth metal halophosphate phosphors
Assignee: Mallinckrodt Chemical Works
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Filing: 1970-02-06
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Granted: 1971-04-20
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Expires: 1990-02-06
Abstract
Abstract APATITE-TYPE FLUORESCNET COMPOSITIONS ARE PREPARED BY FIRST PRECIPITATING AN ALKALINE EARTH HALOPHOSPAHTE INTERMEDIATE THAT IS DEFICIENT IN ANTIMONY ACTIVATOR, THEN DIGESTING THE INTERMEDIATE IN A SOLUTION CONTAINING THE ANTIMONY ACTIVATOR IONS. A FRIEF FIRING DEVELOPS THE FLUORESCENT CAPACITY TO THE CONVENTIONAL RANGE.
Inventors
- 👤 Roger D Piper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:19
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/74; C09K11/75; C09K11/76
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |