US2120538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of oxidizing naphthalene to phthalic anhydride
Assignee: Wyeth Holdings LLC
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Filing: 1932-06-29
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Granted: 1938-06-14
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Expires: 1952-06-29
Abstract
No abstract record available.
Inventors
- 👤 Chester E Andrews
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:04
CPC Classifications
B; B01; B01J; B01J8/00; B01J8/02; B01J8/06; B01J8/067; C; C07; C07C; C07C51/00; C07C51/16; C07C51/31; C07C51/313; B01J2208/00; B01J2208/00008; B01J2208/00017; B01J2208/00106; B01J2208/00168; B01J2208/00212
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) | 1941-06-13 | 1941-12-13 | 1942-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1945-06-13 | 1945-12-13 | 1946-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1949-06-13 | 1949-12-13 | 1950-06-14 | $7700.00 | Window Closed / Lapsed |