High contrast development of photographic elements
AssigneeEastman Kodak Company
InventorRonald J. Nothnagle
Life of this patent
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Abstract
High contrast development of photographic elements, such as lithographic films used in the field of graphic arts, is carried out in the presence of a hydrazine compound with an aqueous alkaline developing solution which has a pH of above 10 and below 12 and contains a dihydroxybenzene developing agent, a 3-pyrazolidone developing agent, a sulfite preservative, and a contrast-promoting amount of an amino compound. The developing solution combines the advantages of high capacity, a high degree of stability, and a long effective life, while providing excellent contrast and speed characteristics.
Claims25
A method for high contrast development of a photographic element comprising at least one silver halide emulsion layer, which method comprises contacting said element in the presence of a hydrazine compound with an aqueous alkaline developing solution which has a pH of above 10 and below 12 and contains a dihydroxybenzene developing agent, a 3-pyrazolidone developing agent, a sulfite preservative, and a contrast-promoting amount of an amino compound.
A method for high contrast development of a photographic element comprising at least one silver halide emulsion layer containing a hydrazine compound, which method comprises contacting said element with an aqueous alkaline developing solution which has a pH of above 10 and below 12 and contains a dihydroxybenzene developing agent, a 3-pyrazolidone developing agent, a sulfite preservative, and a contrast-promoting amount of an amino compound.
A method for high contrast development of a photographic element comprising at least one silver halide emulsion layer, which method comprises contacting said element with an aqueous alkaline developing solution which has a pH of above 10 and below 12 and contains a hydrazine compound, a dihydroxybenzene developing agent, a 3-pyrazolidone developing agent, a sulfite preservative, and a contrast-promoting amount of an amino compound.
A method for high contrast development of a photographic element comprising at least one silver halide emulsion layer containing 1-formyl-2-{4-[2-(2,4-di-t-pentylphenoxy)butyramido]phenyl}hydrazide, which method comprises contacting said element with an aqueous alkaline developing solution which has a pH in the range of from 10.8 to 11.4 and contains hydroquinone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, sodium sulfite, and a contrast-promoting amount of 2-diethylamino-1-ethanol.
An aqueous alkaline photographic developing solution for use in high contrast processing of photographic elements, said solution having a pH of above 10 and below 12 and containing a hydrazine compound, a dihydroxybenzene developing agent, a 3-pyrazolidone developing agent, a sulfite preservative, and a contrast-promoting amount of an amino compound.
Dependencies are inferred from the claim text.