US3533738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of synthetic mullite
Assignee: WR Grace and Co
•
Filing: 1968-12-16
•
Granted: 1970-10-13
•
Expires: 1988-12-16
Abstract
No abstract record available.
Inventors
- 👤 Clark A Rundell
- 👤 John A Kwedar
- 👤 Heyman C Duecker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:55
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/36; C01B33/38; C01B33/42; B; B01; B01J; B01J21/00; B01J21/16; C01B33/26; C01B33/40; C01B33/46
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1741920A
Cited
US2232727A
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US2428895A
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US2678282A
Cited
US2688003A
Cited
DE1068232B
Cited
US3366445A
Cited
US3459501A
Cited
US3460904A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-10-12 | 1974-04-13 | 1974-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-10-12 | 1978-04-13 | 1978-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-10-12 | 1982-04-13 | 1982-10-13 | $7700.00 | Window Closed / Lapsed |