Calcium ion stable photographic color developing composition and method of use
AssigneeEastman Kodak Company
InventorsShirleyanne E. Haye, Janet M. Huston, William G. Henry
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Abstract
A color developing composition is stable in the presence of calcium ion because of the presence of a specific polyphosphonic acid sequestering agent. The composition also comprises a color developing agent in free base form and an antioxidant for the color developing agent. The calcium ion sequestering agent is morpholinomethanediphosphonic acid or a salt thereof. This sequestering agent can be used alone to control calcium ion precipitates, or in combination with a polyaminopolyphonic acid or salt thereof. The composition can be used to provide images in various color photographic silver halide materials.
Claims20
A photographic color developing composition that, when in aqueous form, has a pH of from about 7 to about 13 and comprises:
- a) at least 0.0005 mol/l of a color developing agent in free base form,
- b) at least 0.0005 mol/l of an antioxidant for said color developing agent, and
- c) at least 0.00005 mol/1 of morpholinomethanedisphosphonic acid or a salt thereof, alone or in combination with at least 0.0005 mol/l of a polyaminopolyphosphonic acid or salt thereof that has at least five phosphonic acid groups.
An aqueous color developing composition having a pH of from about 8 to about 12 and comprising:
- a) from about 0.005 to about 0.03 mol/l of a color developing agent in free base form,
- b) from about 0.005 to about 0.05 mol/l of a hydroxylamine derivative antioxidant for said color developing agent,
- c) a water-miscible or water-soluble hydroxy-substituted, straight-chain organic solvent that has a molecular weight of from about 100 to about 200,
- d) a carbonate buffering agent, and
- e) from about 0.0001 to about 0.0008 mol/l of morpholinomethanediphosphonic acid or a salt thereof, alone or in combination with from about 0.001 to about 0.01 mol/l of diethylenetriamine-pentamethylenephosphonic acid or a salt thereof.
Dependencies are inferred from the claim text.