Weakly alkaline ascorbic acid developing composition, processing kit and method using same
AssigneeEastman Kodak Company
InventorsRobert John Opitz, Silvia Zawadzki
Life of this patent
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Abstract
A black-and-white developing composition includes as ascorbic acid developing agent, an auxiliary super-additive developing agent, borate buffer and a preservative. The composition pH is from 7 but less than 9. The composition can be formulated from two separately packaged parts that may be in dry or liquid form. The borate buffer is present to maintain the desired pH, and the two developing agents are present in desired molar ratios for optimal developing activity. Improved photographic properties are obtained while avoiding the use of environmentally unfriendly dihydroxybenzenes.
Claims13
A method of providing a black-and-white photographic image comprising:
- processing an imagewise exposed black-and-white silver halide photographic material with a black-and-white developing composition that is free of dihydroxybenzene developing agents, said developing composition having a pH of from 7 but less than 9, and comprising:
- an ascorbic acid developing agent,
- an auxiliary super-additive developing agent,
- borate as the sole buffer in an amount of at least 0.001 mol/l, and
- a preservative,
- provided the molar ratio of said ascorbic acid developing agent to said auxiliary super-additive developing agent is at least 10:1.
Dependencies are inferred from the claim text.