Patent US2817074A successfully refreshed from Google Patents.
US3211527A
Expired / Lapsed
US
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Process for producing ultrafine silicon nitride
Assignee: Union Carbide Corp
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Filing: 1962-05-28
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Granted: 1965-10-12
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Expires: 1982-05-28
Abstract
No abstract record available.
Inventors
- 👤 Paul F Forsyth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:04
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/06; C01B21/068
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) | 1968-10-11 | 1969-04-12 | 1969-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-10-11 | 1973-04-12 | 1973-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-10-11 | 1977-04-12 | 1977-10-12 | $7700.00 | Window Closed / Lapsed |