Method for processing silver dye-bleach materials
US4304846A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 4, 1980 |
| Grant date | Dec 8, 1981 |
| Priority date | — |
| Expiry date | Feb 4, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/28
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for processing exposed silver dye-bleach materials using novel preparations for combined dye bleaching and silver bleaching is described. In addition to a strong acid, a water-soluble iodide, a water-soluble oxidizing agent, an antioxidant and, if desired, a bleaching accelerator, these preparations also contain a mixture of 1,4- or 1,2-diazines as bleach catalysts. This mixture consists either of at least two bleach catalysts with redox potentials between +105 mV and -30 mV, the difference between the redox potentials of the catalysts being at least 15 mV, or of at least one bleach catalyst with a redox potential between +60 mV and -30 mV and at least one bleach catalyst with a redox potential between -30 mV and -100 mV, the difference between the redox potentials of the catalysts likewise being at least 15 mV. When exposed dye-bleach materials are processed using these preparations, images with improved color quality are obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.