Photographic materials and processes comprising color-forming sulfonamidodiphenylamine dye precursors and corresponding phenazine dyes
US4368246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 1981 |
| Grant date | Jan 11, 1983 |
| Priority date | — |
| Expiry date | Jul 6, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/156
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
In a photographic material for producing a dye image or a dye image and silver image comprising (1) a photographic metal salt, such as photographic silver halide, and (2) a dye precursor, improved images are provided by means of a color-forming para-sulfonamidodiphenylamine dye precursor having one to two sulfonamido groups in positions ortho to the --NH-- moiety separating the two phenyl groups of the sulfonamidodiphenylamine and wherein the sulfonamidodiphenylamine, in oxidized form, intramolecularly reacts to produce a sulfonamido-substituted phenazine dye. An exposed photographic material containing the color-forming sulfonamidodiphenylamine dye precursor is processed to produce a negative phenazine dye-enhanced silver image. Alternatively, the exposed photographic material is processed to produce a positive phenazine dye image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.