Abstract: Certain organic carbocyclic and heterocyclic compounds are useful catalysts for hydrogen peroxide bleaching agents in photographic processing methods. These compounds are oxidizable by hydrogen peroxide and reducible by silver metal at a pH of from 1 to 7, and have a chemically reversible redox couple of from about -0.20 to about +1.0 volts at the same pH. The hydrogen peroxide bleaching ability is enhanced by the presence of these compounds which can be used in the bleaching solution itself, or in a prebath solution. The combination of the organic compound with a transition metal ion co-catalyst provides a synergistic effect in bleaching acceleration.

Abstract: A simple and effective bleaching method includes the use of a bleaching solution including a peroxide bleaching agent and chloride ion in an amount of at least 0.35 mol/l. An organic phosphonic acid or tertiary aminocarboxylic acid can also be present for stability. The method is useful for bleaching color photographic films containing at least 20 mol % silver bromide and from 0 to about 0.5 mol % silver iodide in at least one silver halide emulsion.

Abstract: A method of treating a halogenated polymeric-containing substrate including exposing at least portions of the halogenated polymeric-containing substrate to a composition containing a reducing agent and an aprotic solvent selected from the group consisting of nitriles, nitro compounds, amides, esters, carbonates, oxides, sulfo compounds and mixtures thereof. The solvent is free of ethers, amines, ammonia. The composition is prepared by reacting a metal with an organic compound selected from the group consisting of polyaryl compounds, aromatic carbonyl containing compounds, aromatic nitriles, and aromatic heterocyclic nitrogen containing compounds in a reaction solvent that does not react with the metal but permits reaction between the metal and the organic compound to thereby provide the reducing agent. The reducing agent is isolated from the reaction solvent to obtain a reaction product as a solid. The reaction product is added to the aprotic solvent.

Abstract: Certain organic carbocyclic and heterocyclic compounds are useful catalysts for hydrogen peroxide bleaching agents in photographic processing methods. These compounds are oxidizable by hydrogen peroxide and reducible by silver metal at a pH of from 1 to 7, and have a chemically reversible redox couple of from about -0.20 to about +1.0 volts at the same pH. The hydrogen peroxide bleaching ability is enhanced by the presence of these compounds which can be used in the bleaching solution itself, or in a prebath solution. The combination of the organic compound with a transition metal ion co-catalyst provides a synergistic effect in bleaching acceleration.

Abstract: Certain organic carbocyclic and heterocyclic compounds are useful catalysts for hydrogen peroxide bleaching agents in photographic processing methods. These compounds are oxidizable by hydrogen peroxide and reducible by silver metal at a pH of from 1 to 7, and have a chemically reversible redox couple of from about -0.20 to about +1.0 volts at the same pH. The hydrogen peroxide bleaching ability is enhanced by the presence of these compounds which can be used in the bleaching solution itself, or in a prebath solution. The combination of the organic compound with a transition metal ion co-catalyst provides a synergistic effect in bleaching acceleration.