Photographic peracid bleaching composition and processing method using ternary iron carboxylate complexes as catalysts in peracid bleaching solutions
US5521056A · kind A · utility
13Cited by
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21Claims
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Key dates
| Filing date | Jan 10, 1995 |
| Grant date | May 28, 1996 |
| Priority date | — |
| Expiry date | Jan 10, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/144
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photographic peracid bleaching composition contains a peracid bleaching agent, and a water-soluble ternary complex of ferric ion, a polycarboxylate ligand, and a second ligand which has at least one carboxyl group on an aromatic nitrogen heterocycle, such as a pyridinecarboxylic acid. These complexes act as catalysts for the peracid bleaching agent. Preferred complexes are biodegradable, but all of the ternary complexes can be used in a variety of peracid bleaching processes to good advantage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.