Fixer additives used in combination with iron complex based bleaches to prevent iron retention
US5508150A · kind A · utility
7Cited by
15References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1993 |
| Grant date | Apr 16, 1996 |
| Priority date | — |
| Expiry date | Dec 29, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/421
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of processing an image wise exposed and developed silver halide photographic element comprising bleaching the photographic element in a bleaching or bleach-fixing solution containing as the primary bleaching agent a complex of ferric ion and a tridentate or a tetradentate ligand, and then processing the photographic element in a solution containing a chelating compound represented by Formula I EQU HOOC(CH.sub.2).sub.m (X) ((CH.sub.2).sub.n COOH).sub.2 (I) where PA1 X is N, or C--OH; PA1 n and m are independently 0, 1, or 2; and PA1 M is a cationic ion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.