Dye bleach preparation for the photographic silver dye bleach process
US3961957A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 1974 |
| Grant date | Jun 8, 1976 |
| Priority date | — |
| Expiry date | May 10, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/44
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention relates to a dye bleach preparation which contains in addition to an acid, a water-soluble iodide and optionally a dye bleach catalyst at least one bifunctional sulphur compound having a sufficient solubility in the preparation and a low vapor pressure and containing at least one HS-group and at least one oxygen, nitrogen, phosphorus or additional sulphur atom, the sulphur atom of each HS-group being separated from the next oxygen, sulphur, nitrogen and phosphorus atom present in the molecule by at least three carbon atoms. The subject of the present invention is a dye bleach preparation for the photographic silver dye bleach process, which contains an acid, a water-soluble iodide and optionally a dye bleach catalyst. The preparation is characterised in that it contains at least one organic, at least bifunctional sulphur compound of which the solubility is at least 5.times.10.sup.-.sup.4 mol per liter of preparation and of which the vapour pressure in the temperature range of -20.degree.C to +100.degree. C is at most as great as that of water, and which contains at least one HS-- group and at least one oxygen, nitrogen, phosphorus or additional sulphur atom, with the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.