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.
Claims11
A two-part color developing composition kit comprising:
- I) a first aqueous solution having a pH of from about 9 to about 13, and
- II) a second aqueous solution having a pH of from about 3 to about 7 and comprising:
- (a) at least 0.005 mol/l of a color developing agent,
- (b) at least 0.005 mol/l of an antioxidant for said color developing agent, and
- (c) at least 0.001 mol/l of sulfite ions,
- further comprising, in said first aqueous, 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 10,000, and in said first or second aqueous solution, or both, 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 when said first and second aqueous solutions are mixed at a volume ratio of from about 2:1 to about 1:2.
A three-part color developing kit comprising:
- (I) a first concentrated aqueous solution having a pH of from about 9 to about 13,
- (II) a second concentrated aqueous solution having a pH of from about 1 to about 4 and comprising:
- (a) at least 0.0005 mol/l of a color developing agent, and
- (b) at least 0.0005 mol/l of sulfite ions, and
- (III) a third concentrated aqueous solution having a pH of from about 10 to about 13.5,
- wherein said first or second concentrated aqueous solution, or both, includes 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 10,000, any of said first, second, and third concentrated aqueous solutions includes at least 0.001 mol/l of a second calcium ion sequestering agent that is a non-polymeric aminocarboxylic acid, polyphosphonic acid, or a salt thereof, and any of said first, second, and third concentrated aqueous solutions includes at least 0.005 mol/l of an antioxidant for said color developing agent,
- 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 when said first, second, and third concentrated aqueous solutions are mixed at a volume ratio of 2:1:3.
Dependencies are inferred from the claim text.