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.