US3672891A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic element and process comprising a pyrimidine silver halide developing agent
Assignee: Eastman Kodak Co
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Filing: 1969-10-02
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Granted: 1972-06-27
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Expires: 1989-10-02
Abstract
Abstract PHOTOGRAPHIC DEVELOPING AGENTS WHICH ARE PYRIMIDINE COMPOUNDS SUCH AS 5-HYDROXY AND/OR 5-AMINO-PYRIMIDINE DEVELOPING AGENTS PROVIDE REDUCED STAIN WITHOUT LOSS OF DESIRED SENSITOMETRIC PROPERTIES IN A DIFFUSION TRANSFER SYSTEM. THESE CAN BE USED IN COMBINATION WITH OTHER PHOTOGRAPHIC DEVELOPING AGENTS, SUCH AS REDUCTONE DEVELOPING AGENTS, AMINOMETHYL HYDROQUINONE DEVELOPING AGENTS, CINNAMIC ACID DEVELOPING AGENTS, LACTONE DEVELOPING AGENTS, OR DEVELOPING AGENT PRECURSORS E.G. COUMARIN DEVELOPING AGENTS OR DEVELOPING AGENT PRECURSORS. THEY ARE ESPECIALLY USEFUL IN A BLACK-AND-WHITE SILVER SALT DIFFUSION TRANSFER PROCESS.
Inventors
- 👤 Edwin B Wyand
- 👤 William C Farley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:31
CPC Classifications
G; G03; G03C; G03C8/00; G03C8/02; G03C8/04; G03C8/06
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |