Patent US3684731A successfully refreshed from Google Patents.
US3684731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing copper resistant silver activated zinc sulfide phosphors
Assignee: GTE Sylvania Inc
•
Filing: 1970-10-08
•
Granted: 1972-08-15
•
Expires: 1990-10-08
Abstract
Abstract AN IMPROVEMENT IN THE PROCESS FOR PREPARING SILVERACTIVATED ZINC SULFIDE PHOSPHORS, WHICH IMPARTS TO THE PHOSPHOR A COPPER RESISTANCE, WHICH COMPRISES ADJUSTING THE PH OF THE PHOSPHOR-WATER WASH SLURRY FROM ABOUT 7.5 TO ABOUT 9.5 AND AGITAING FOR A GIVEN PERIOD OF TIME, BEFORE FILTERING AND DRYING THE PHOSPHOR.
Inventors
- 👤 James O Frey
- 👤 Henry B Minnier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:33
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/58; C09K11/582; C09K11/584
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |