Mixture of nondiffusible redox dye-releasers for curve shape control
US4391896A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1978 |
| Grant date | Jul 5, 1983 |
| Priority date | — |
| Expiry date | Sep 20, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Curve shape control, especially for lower scale contrast, of a photographic element is achieved by employing with the silver halide emulsion layer two nondiffusible redox dye-releasing compounds of different relative reactivities, the reactivity of the compound which is more reactive being at least 1.5 times the reactivity of the compound which is less reactive. Preferred compounds are ballasted sulfonamido compounds, each of which has a color-providing moiety attached thereto through a sulfonamido group which is alkali-cleavable upon oxidation. Preferred more reactive sulfonamido compounds have a N,N-disubstituted carbamoyl ballast group. The color-providing moieties can be (1) transferred imagewise to an image-receiving layer to provide a useful image, or (2) can be merely diffused out of the element to provide a retained image therein which can be treated to form a color transparency or a motion picture film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.