US2618558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic developers comprising an n,n - dialkyl-p-phenylenediamine and a benzenesulfonate
Assignee: Eastman Kodak Co
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Filing: 1949-04-12
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Granted: 1952-11-18
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Expires: 1969-04-12
Abstract
No abstract record available.
Inventors
- 👤 Paul W Vittum
- 👤 George W Kerridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:24
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/305
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
20 words
A PHOTOGRAPHIC DEVELOPING SOLUTION COMPRISING AN N,N-DIALKYL-P-PHENYLENEDIAMINE DEVELOPING AGENT AND A SUBSTANTIAL AMOUNT OF A COMPOUND OF THE FOLLOWING STRUCTURE:
Claim 2
Dependent Claim
20 words
A PHOTOGRAPHIC DEVELOPING SOLUTION COMPRISING AN N,N-DIALKYL-P-PHENYLENEDIAMINE DEVELOPING AGENT AND A SUBSTANTIAL AMOUNT OF A COMPOUND OF THE FOLLOWING STRUCTURE:
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-11-18 | 1956-05-19 | 1956-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-11-18 | 1960-05-19 | 1960-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-11-18 | 1964-05-19 | 1964-11-18 | $7700.00 | Window Closed / Lapsed |