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US 6,686,135 B2Granted
Stabilized black-and-white developing compositions and methods of use
AssigneeEastman Kodak Company
InventorsPaul A. Schwartz, Susan M. Flavin
Life of this patent
Estimating the term…
Abstract
A black-and-white photographic developing composition or developing kit includes an ascorbic acid developing agent and is essentially free of hydroquinone and similar developing agents. The developing composition further includes a water-miscible hydroxy-containing organic solvent having a molecular weight of from about 50 to about 200. The weight ratio of the organic solvent to water is from about 0.1:1 to about 8:1.
Claims8
A two-part aqueous black-and-white developing composition kit comprising:
- a) an aqueous first solution having a pH of from about 3 to about 6 that is essentially free of dihydroxybenzene compounds and comprises:
- at least 0.05 mol/l of an ascorbic acid developing agent,
- a water-miscible hydroxy-containing organic solvent having a molecular weight of from about 50 to about 200, the weight ratio of said organic solvent to water being from about 0.05:1 to about 8:1, and
- at least 0.0005 mol/l of a 3-pyrazolidone co-developing agent, and
- b) a second aqueous solution having a pH of from about 8 to about 12 and comprising a borate buffer and at least 0.05 mol/l of sulfite ions.
2 more elements
Dependencies are inferred from the claim text.