US3647469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bisaminoalkyl disulfides as sensitizers and stabilizers for silver halide emulsions
Assignee: Agfa Gevaert AG
•
Filing: 1969-12-19
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Granted: 1972-03-07
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Expires: 1989-12-19
Abstract
Abstract The present invention relates to a process for increasing the sensitivity of photographic silver halide emulsions together with reduced fogging by the addition of bis-aminoalkyl disulfides.
Inventors
- 👤 Harald Huckstadt
- 👤 Wilhelm Saleck
- 👤 August Randolph
- 👤 Franz Moll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:40
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/08; G03C1/09; G03C1/34; G03C1/346
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
18 words
A light sensitive photographic material according to claim 1, wherein the emulsion layer in addition contains color couplers.
Claim 2
Dependent Claim
69 words
In the process for the preparation of photographic silver halide emulsions by the precipitation of the silver halide in the presence of the protective colloid, and washing and chemical ripening the improvement according to which the chemical ripening is carried out in the presence of an effective amount of a compound of the following formula: H2N-(CH2)n-S-S-(CH2)n-NH2.2HX wherein n 2 or 3; X the anion of any photographically inert acid.
References Cited (Backward Citations)
US2438716A
Cited
US3057725A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |