Patent US2943109A successfully refreshed from Google Patents.
US2943109A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic developers
Assignee: Imperial Chemical Industries Ltd
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Filing: 1958-05-14
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Granted: 1960-06-28
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Expires: 1978-05-14
Abstract
No abstract record available.
Inventors
- 👤 Ramsay David William Crichton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:48
CPC Classifications
C; C07; C07D; C07D215/00; C07D215/02; C07D215/16; C07D215/38; G; G03; G03C; G03C7/00; G03C7/30; G03C7/407; G03C7/413; G03C7/4136
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
20 words
THE SALTS OF PHOTOGRAPHIC DEVELOPERS SELECTED FROM THE GROUP CONSISTING OF O-AMINO PHENOL, P-AMINOPHENOL AND P-PHENYLENE DIAMINES HAVING THE FORMULA
Claim 2
Dependent Claim
20 words
THE SALTS OF PHOTOGRAPHIC DEVELOPERS SELECTED FROM THE GROUP CONSISTING OF O-AMINO PHENOL, P-AMINOPHENOL AND P-PHENYLENE DIAMINES HAVING THE FORMULA
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) | 1963-06-28 | 1963-12-28 | 1964-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-06-28 | 1967-12-28 | 1968-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-06-28 | 1971-12-28 | 1972-06-28 | $7700.00 | Window Closed / Lapsed |