Photographic silver halide developer composition and process for forming photographic silver images
US5578434A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1995 |
| Grant date | Nov 26, 1996 |
| Priority date | — |
| Expiry date | May 15, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/30
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention relates to a black-and-white aqueous alkaline photographic developer composition, free of dihydroxybenzene developing agent, comprising a reductic acid developing agent and an auxiliary superadditive developing agent, wherein the reductic acid developing agent is represented by the formula (I): ##STR1## wherein, R.sub.1, R.sub.2, R.sub.3 and R.sub.4 each are selected from the group consisting of hydrogen and group CH.sub.2 R.sub.5, wherein R.sub.5 is hydrogen or a monovalent group, e.g. amino, cyano, halogen, hydroxyl, carboxyl, sulfonyl, alkyl, cycloalkyl, aryl. A process for forming a black-and-white photographic silver image comprising developing a silver halide photographic element with said black-and-white aqueous alkaline photographic developer composition is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.