Ascorbic acid developing compositions stabilized with sulfo compound and methods of use
AssigneeEastman Kodak Company
InventorsShirleyanne E. Haye, Janet M. Huston, John S. Badger, Jacques Roussilhe
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Abstract
A black-and-white photographic developing composition has improved stability and is more compatible with the environment when discarded. The composition includes one or more ascorbic acid developing agents and a preservative (such as a sulfite) and is essentially free of hydroquinone and similar developing agents. Improved stability is provided using a sulfo-substituted organic compound as a stabilizing agent. Such compounds are either aliphatic sulfo compounds or hydroxy-free aromatic sulfo compounds.
Claims14
A black-and-white photographic developing composition that is essentially free of dihydroxybenzene compounds and comprises:
- a) an ascorbic acid developing agent,
- b) a stabilizing amount of methanesulfonic acid, taurine, 4-sulfoisophthalic acid, 5-sulfoisophthalic acid, or a salt of any of these compounds, and
- c) a preservative.
An aqueous black-and-white photographic developing composition that has a pH of from about 8 to about 11, is essentially free of dihydroxybenzene compounds and comprises:
- a) from about 0.05 to about 0.3 mol/l of an ascorbic acid developing agent,
- b) from about 0.05 to about 0.25 mol/l of methanesulfonic acid, taurine, 4-sulfoisophthalic acid, 5-sulfoisophthalic acid, a salt of any of these, or a mixture of any two or more of these, as stabilizing agents,
- c) from about 0.05 to about 0.5 mol/l of a sulfite preservative,
- d) from about 0.01 to about 0.04 mol/l of a 3-pyrazolidone co-developing agent,
- e) an organic antifoggant.
A method of providing an image comprising contacting an imagewise exposed silver halide photographic material with the following black-and-white photographic developing composition for at least 10 seconds:
- a black-and-white photographic developing composition that is essentially free of dihydroxybenzene compounds and comprises:
- a) an ascorbic acid developing agent,
- b) a stabilizing amount of methanesulfonic acid, taurine, 4-sulfoisophthalic acid, 5-sulfoisophthalic acid, or a salt of any of these compounds, and
- c) a preservative.
Dependencies are inferred from the claim text.