Photographic color developing composition containing calcium ion sequestering agent combination and method of use
AssigneeEastman Kodak Company
InventorsShirleyanne E. Haye, Janet M. Huston
Life of this patent
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Abstract
Concentrated and working strength photographic color developing compositions are stabilized with the inclusion of two specific types of calcium ion sequestering agents. One of the sequestering agents is a polyelectrolyte such as a polycarboxylic acid or salt thereof having a molecular weight of from about 2000 to about 100,000. The other one is a non-polymeric aminocarboxylic acid, polyphosphonic acid, or a salt thereof. The weight ratio of the first calcium ion sequestering agent to the second calcium ion sequestering agent is from about 1:1 to about 20:1. These compositions can be used to process color photographic materials such as color photographic papers.
Claims12
A aqueous photographic color developing composition having a pH of from about 7 to about 13 and comprising:
- a) at least 0.0005 mol/l of a color developing agent,
- b) at least 0.0005 mol/l of an antioxidant for said color developing agent,
- c) from about 1 to about 25 g/l of a first calcium ion sequestering agent that is a polycarboxylic acid or salt thereof having a molecular weight of from about 2000 to about 10,000, and
- d) at least 0.0005 mol/l of a second calcium ion sequestering agent that is a non-polymeric aminocarboxylic acid, polyphosphonic acid, or a salt thereof,
- wherein the weight ratio of said first calcium ion sequestering agent to said second calcium ion sequestering agent is from about 1:1 to about 20:1.
A concentrated, aqueous, single-part color developing composition having a pH of from about 8 to about 12 and comprising:
- a) from about 0.005 to about 1 mol/l of a color developing agent in free base form,
- b) from about 0.005 to about 1 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 50 to about 200,
- d) a buffering agent that is soluble in said organic solvent,
- e) from about 1 to about 50 g/l of a first calcium ion sequestering agent that is a polycarboxylic acid or salt thereof having a molecular weight of from about 2000 to about 10000, and
- f) from about 0.001 to about 0.3 mol/l of a second calcium ion sequestering agent that is a non-polymeric aminocarboxylic acid, polyphosphonic acid, or a salt thereof
- wherein the weight ratio of said first calcium ion sequestering agent to said second calcium ion sequestering agent is from about 1:1 to about 15:1.
Dependencies are inferred from the claim text.