Process for producing a high contrast photographic image
US4221857A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 18, 1978 |
| Grant date | Sep 9, 1980 |
| Priority date | — |
| Expiry date | Aug 18, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/305
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for producing a high contrast photographic image comprising developing an image-wise exposed silver halide photographic light-sensitive material comprising a support having thereon at least one silver halide emulsion layer with a developer containing (a) free sulfite ion in a concentration of at least 0.18 mol/l and (b) as substantially the only developing agent a dihydroxybenzene in the presence of (i) at least one compound represented by the following general formula (I); EQU R.sup.1 NHNHCOR.sup.2 (I) wherein R.sup.1 represents an aryl group; R.sup.2 represents a hydrogen atom, a phenyl group or an unsubstituted alkyl group having 1 to 3 carbon atoms and (ii) at least one polyalkylene oxide having a molecular weight of at least 600 or a derivative thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.