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US 5,508,151 AGranted
Processing of photographic elements using copper ligand complexes to catalyze peracid bleaching agents
AssigneeEastman Kodak Company
InventorsTerrence R. O'Toole, Mark F. Sistare, Eric R. Schmittou
Life of this patent
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Abstract
Copper (II) ligand complexes are useful to catalyze the activity of peracid bleaching agents. The complexes can be included in the bleaching solutions, or used in a suitable solution prior to the bleaching step. The ligands are .alpha.-diimines having sites available to complex with copper (II).
Claims16
A method for processing a color silver halide photographic element comprising:
- treating an imagewise exposed and developed color silver halide photographic element with a peroxide bleaching solution comprising a peroxide bleaching agent, and a complex of copper(II) ion and an .alpha.-diimine ligand, said copper(II) ion being present in an amount of at least about 0.0002 mol/l, and said peroxide bleaching solution having a molar ratio of copper(II) ion to said ligand of less than or equal to about 4:1.
A method for processing a color silver halide photographic element comprising:
- A) treating an imagewise exposed and developed color silver halide photographic element with a solution comprising a complex of copper(II) ion and an .alpha.-diimine ligand, said copper(II) ion being present in an amount of at least about 0.0002 mol/l, and said solution having a molar ratio of copper(II) ion to said ligand of less than or equal to about 4:1, and
- B) bleaching said element with a peroxide bleaching solution comprising a peroxide bleaching agent.
A peroxide bleaching solution comprising:
- a peroxide bleaching agent,
- a complex of copper(II) ion and an .alpha.-diimine ligand, said copper((II) ion being present in an amount of at least about 0.0002 mol/l, and said solution having a molar ratio of copper(II) ion to said ligand of less than or equal to 4:1, and
- a rehalogenating agent.
Dependencies are inferred from the claim text.