| 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. |