Activator solution with cold image tone-providing agent
AssigneeEastman Kodak Company
InventorDonald F. McLaen
Life of this patent
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Abstract
Potassium iodide (or a related iodide) when incorporated in an alkaline activator for use in a rapid access processor using developer-incorporated, resin-coated paper, (i) produces a cold image tone in black-and-white photographic prints, and (ii) maintains the image tone of a large number of prints within a narrow image tone range over a (one week or one thousand 8.times.10 inch print) design life of the activator solution.
Claims6
A cold tone-providing, activator solution suitable for use in preparing black-and-white photographic prints from developer incorporated, resin-coated photographic prints using a rapid access automated processing apparatus, said solution providing
- (i) from about 1.0 to about 8.0 g/l of an alkali metal iodide,
- (ii) sufficient alkali to provide enough hydroxyl ions to:
- (a) combine with all hydrogen ions liberated from the developer to form water,
- (b) to neutralize any acid by-products produced on formation of the silver image, and
- (c) to combine with alkali metabisulfite to provide a solution of sufficient alkalinity, a pH of from about 12 to about 14.5 so that image development can take place, and
- (iii) a stabilizer quantity of said alkali metal metabisulfite.
An activator/image tone-providing composition comprising per liter of water:
- 1 gram of ethylene diamine tetraacetic acid disodium salt,
- 218.4 grams of KOH
- 14.6 grams of sodium metabisulfite
- 2.0 grams of KBr, and from about 1.0 to about 8.0 grams of potassium iodide.
Dependencies are inferred from the claim text.