US2481744A
Expired / Lapsed
US
⏱️ 0.0 years remaining
3':4'-phthaloylacridones
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1945-08-14
•
Granted: 1949-09-13
•
Expires: 1965-08-14
Abstract
No abstract record available.
Inventors
- 👤 Heslop Robert Norman
- 👤 Irving Francis
- 👤 Livingston Alistair
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:34
CPC Classifications
C; C09; C09B; C09B5/00; C09B5/24; C09B5/34; C09B5/36
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE287614C
Cited
US961047A
Cited
US998772A
Cited
US1002270A
Cited
GB191100894A
Cited
US2005321A
Cited
US2052592A
Cited
US2133274A
Cited
US2374891A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-09-12 | 1953-03-14 | 1953-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-09-12 | 1957-03-14 | 1957-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-09-12 | 1961-03-14 | 1961-09-13 | $7700.00 | Window Closed / Lapsed |