Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
  • G03C7/30—Colour processes using colour-coupling substances; Materials therefor; Preparing or processing such materials
  • G03C7/407—Development processes or agents therefor
  • G03C7/413—Developers
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/29—Development processes or agents therefor
  • G03C5/305—Additives other than developers

Definitions

• This invention relates to photographic developers and particularly to an improved firstde- Veloper for multi-layer color film of the reversal type.
• silver-halide grains are reduced to metallic silver.
• the developing agents heretofore employed contain, in addition to the organic reducing agent such as hydroquinone or p-monomethylaminophenol, a small quantity of potassium bromide and sodium thiocyanate.
• the potassium bromide lowers the degree of ionization of silver bromide and by reducing the concentration of silver cations restrains development, whereas the sodium thiocyanate dissolves the residual silverhalide, which otherwise would prevent the clearing out of the highlight portions of the image.
• Another object is to provide an improved first developer for reversal multi-layer color film which restrai-ns the development of the yellow top layer and produces-a greater density in such layer.
• the iodide ion is absorbed on the silver bromide crystal, in some cases ac-' tually replacing the bromideion inthe-latti'ce of the silver-h-alide.-
• the absorbed iodide ion greatly reduces the solubility of the silver ha-lide crystal in the silver solventsuch as sodium thiccyanate, etc.
• Photographic multi-layer color materials which may be developed with the first developer in ac-- cordance with the present invention, include all color reversible film.
• Such-color reversible film consists of an integral tripack emulsion coated on the usual clear cellulose acetate or nitrate filmbase.
• Each of the emulsions is sensitized toone of the primary colors, namely, blue, green, and red.
• the top layer is blue sensitive;
• the filter layer yellow in color and blue absorbing, lies A 4" x multi-layer color film sheet of the reversal type, such as prepared according to United States Patents 2,179,228; 2,179,239; 2,186,- 849 and 2,220,187, was exposed and developed for minutes at 68 F. in a developer of the following composition:
• the developed film was short stopped for 3 minutes in a 3% aqueous solution of acetic acid, and washed for 2 minutes in running water.
• the washed film was given a second exposure for 3 minutes to light of a N0. 1 photofiood lamp 30 inches away from the film.
• the reexposed film was color developed for minutes in a developer of the following composition:
• the color developed film was rinsed for 1 minute in running water, and hardened for 5 minutes in a 3% aqueous solution of chrome alum.
• the hardened film was washed for 5 minutes in running water, and bleached for 10 minutes in a bath of the following composition:
• the bleached film was then washed in running water for 5 minutes, fixed in a solution of hypo for 5 minutes, Washed for another 5 minutes in running water and then dried.
• the resulting transparency was of superior quality and showed a greater density in the top yellow layer with a pleasing color balance in all layers.
• ethylenediamine or its salts such as the sulfate, chloride, tc. and ammonium chloride may be employed in a concentration ranging from 1 to 8 grams per liter of developer.
• any reducing agent which is normally employed in black and white developers may be used, provided it does 4 not color or stain the mutilayer film as pyrogallol does.
• the improvement comprising using as the first developing bath an aqueous developing solution comprising a developing agent for silver-halide, potassium bromide, a silver solvent, and potassium iodide in an amount ranging from 2 to 12 mgs. per liter of developer.
• the silver solvent is a member selected from the class consisting of sodium thiocyanate, ammonium chloride, and ethylenediamine and its salts.
• the improvement comprising using as the first developing bath an aqueous developing solution comprising a developing agent for silver-halide, potassium bromide, sodium thiocyanate, and potassium iodide in an amount ranging from 2 to 12 mgs. per liter of developer.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=25139652

Family Applications (1)

Country Status (4)

Cited By (3)

Citations (10)

Family Cites Families (2)

• 0
  • BE BE484696D patent/BE484696A/xx unknown
• 1947
  • 1947-11-18 US US786811A patent/US2553498A/en not_active Expired - Lifetime
• 1948
  • 1948-07-21 GB GB19551/48A patent/GB640136A/en not_active Expired
• 1949
  • 1949-01-01 DE DEP29332A patent/DE968447C/de not_active Expired

Patent Citations (10)

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