Bleach regenerator composition and its use to process reversal color photographic elements
US6451519B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1997 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Apr 17, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/44
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A ferric-EDTA bleach regenerator composition can be mixed with bleach overflow to provide a bleach replenisher for reversal color silver halide photographic processes. The bleach regenerator composition has a critically controlled pH between about 6.0 and about 6.5, and comprises a total bromide ion concentration of at least about 210 g/l, and ferric ion in an amount of at least about 50 g/l. At least 50% of the bleach overflow and the bleach regenerator composition are mixed in at least a 1:1 volume ratio. After pH adjustment to from about 5.4 to about 5.6, the pH adjusted replenisher is supplied to the bleach tank for use in the process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.