Photographic processing composition and method using cationic hydroquinone as organic catalyst for persulfate bleaching agent

A method for processing a photographic element comprising:

• A) treating an imagewise exposed and developed photographic element with a nonbleaching solution comprising at least about 0.0005 mol/l of a cationic hydroquinone which has the following properties:
• a) a reduced form which is oxidizable by a persulfate at a pH of from about 1 to about 7,
• b) an oxidized form which is reducible by silver metal in the presence of bromide or chloride at a pH of from about 1 to about 7,
• c) a chemically reversible redox couple, versus a saturated calomel electrode, of from about -0.20 to about +1.5 volts, and
• d) is represented by the structure (I) or (II):
• ##STR4## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are independently hydrogen, halo, nitro, sulfonate, phosphonate, amide, sulfonamide, carboxyl, hydroxy, an ester, an ether, a primary, secondary or tertiary amine, an alkyl group of 1 to 12 carbon atoms, an aryl group of 6 to 12 carbon atoms in the ring structure, a cycloalkyl group of 5 to 12 carbon atoms in the ring structure or a quaternized aliphatic or aromatic amine, or
• any two adjacent groups chosen from R.sub.1, R.sub.2, R.sub.3 and R.sub.4, can represent the carbon, nitrogen, oxygen or sulfur atoms necessary to complete a 5- to 12-membered fused carbocyclic or heterocyclic ring structure connected to the primary nucleus of structure (I) or (II),
• provided at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is a quaternized aliphatic or aromatic amine, or at least one ring structure formed from adjacent groups contains a quaternized amine or imine moiety,
• X is an anion,
• m is the absolute value of the ratio of n to y,
• n is 1 to 3,
• y is a negative integer having an absolute value of 1 to 3, and
• B) bleaching said treated film with a persulfate bleaching solution.