Photographic processing using biodegradable bleaching agent followed by fixing
US6197483A · kind A · utility
1Cited by
11References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1998 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Dec 18, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/52
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Color photographic silver halide materials, especially color photographic papers, are processed effectively with reduced iron retention after bleaching with a biodegradable bleaching composition. Bleaching is accomplished using an iron chelate of a biodegradable chelating ligand in the presence of a polyphosphonic acid. This bleaching step is followed by fixing using a fixing composition that includes a fixing agent and a polycarboxylic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.