Patent US3826659A successfully refreshed from Google Patents.
US3826659A
Expired / Lapsed
US
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High zirconia containing glass ceramics
Assignee: National Research Development Corp UK
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Filing: 1972-05-01
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Granted: 1974-07-30
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Expires: 1992-05-01
Abstract
Abstract A GLASS CERAMIC MATERIAL COMPRISING BY WEIGHT 20% TO 45% ZRO2, 20% TO 60% AL2O3, 0% TO 25% SIO2, 0% TO 30% CAO, 0% TO 10% NA2O, THE MATERIAL INCLUDING B2O3 AND/OR PHO IN THE AMOUNTS UP TO 35% AND 25% RESPECTIVELY, B2O3 IN THE ABSENCE OF PBO BEING IN AN AMOUNT MORE THAN 5%, PBO IN THE ABSENCE OF B2O3 BEING IN AN AMOUNT MORE THAN 2%.
Inventors
- 👤 T Busby
- 👤 G Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:40
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C03; C03C; C03C10/00; C03C10/0036; C03C10/0054; C03C12/00; C04B35/10
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) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |