Process for the prevention of darkening and the formation of a sediment in photographic developer solutions
US4254215A · kind A · utility
17Cited by
4References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1979 |
| Grant date | Mar 3, 1981 |
| Priority date | — |
| Expiry date | Mar 26, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/305
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process is described for the prevention of darkening and the formation of a sediment in photographic developer solutions which contain a silver halide developer, a water-soluble silver halide solvent and organic sulfur compounds. The organic sulfur compounds are a combination of (a) an organic thiol compound or thione compound capable of tautomerism and (b) a Bunte salt which contains groups conferring solubility in water. Developer solutions which contain the indicated combination of sulfur compounds are outstandingly stable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.