US3674703A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of silver dispersions for use in filter and antihalation layers
Assignee: Agfa Gevaert AG
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Filing: 1970-03-26
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Granted: 1972-07-04
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Expires: 1990-03-26
Abstract
Abstract Silver dispersions for photographic filter and antihalation layers are produced by reduction of an aqueous silver salt solution containing a protective colloid with a compound of the oxytetronic acid series, such as ascorbic acid. Reduction is carried out in the presence of cadmium ions. This causes the silver to be precipitated in very fine grains in the dispersion so that neutral gray silver dispersions with a high covering power are obtained.
Inventors
- 👤 Franz Moll
- 👤 Rolf-Fred Posse
- 👤 Werner Ringe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:15
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/76; G03C1/825; G03C1/8255
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) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |