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
  • G03C7/28—Silver dye bleach processes; Materials therefor; Preparing or processing such materials

Definitions

• This invention relates to a method for producing colored photographic images and particularly to a method of forming colored images in image in which a dyed gelatin layer containing a silver image is treated with a solution of a strong reducing agent such as sodium hydrosulilte or stannous chloride.
• the reducing bleach bath destroys the dye in the layer selectively in the region of the silver image, giving'a positive dye image from a. negative silver image.
• the destruction of a dye to form a photographic image in this process appears to depend upon the catalytic action of the silver image which results in the destruction of thedye in that portion of the film when treated with a suitable reducing bleach bath.
• the silver salt image may be produced, for example, by rehalogenizing a developed and fixed'silver image.
• an objeetto provide a novel method of forming a colored photographic image in a photographic layer.
• A-iurther object is to provide a novel method for destroying a dye uniformly dispersed in a photographic layer under the influence of a silver salt image.
• the photographic element treated according to my invention may comprise a single emulsion of poly-azo dyes as disclosed in Christensen U. S.
• the three emulsion layers preferably contain dyes coupling with 2 mols of R-salt.
• the red sensitive layer may be colored blue-green with one of the following dyes.
• Example 1 Pontamine Fast Green 581. (Du Pont)
• Example 2. A blue dye of less suitable color, bfit of satisfactory bleaching properties, made by tetrazotizing 4,4"-diamino-2,2'-dimethyl, 5,5'-dimethoxy triphenylmethane and coupling it with two mols of chromotropic acid.
• the green-sensitive magenta with one of the following dyes, some of which are described in Seymour, Young, and
• Example 4. Monosol Carmine LS (Color Index Example 5.-A dye made by tetrazotizing 4,4 diamino-Zi,3'-dimethoxy diphenyl methane and Example 6. The dye made by tetrazotizing 1 mol of 4,4'-diamino triphenyl methane and coupling with 2 mols of N-lauroyl H-acid.
• Example 7 The dyes made by tetrazotizing 1 1 mol of 4,4'-diamino-3,3', 6,6'.-tetramethyl triphenyl methane and coupling-with 2 mols of N-he'ptoyl H-acicl or one of the following compounds:
• Example Z --N(naphthalene B sulfonyl) H- acid.
• Example 1%.Thfi dye made by tetrazotlzing 4,4'-diam.ino 2,2-dimetl1yl-5,5-dimethoxy trl phenylmethane and coupling with .2 mols of 1-naphthol-8-para-tolyl sulionatedfi-disulionlc acid.
• Example i The dye made by tetrazotizing Pool-amine l'liaao Yellow 2G1 and coupling with layer may be colored Example 19.--The dye made by tetrazotizing 4A-cliamino3,3-dimethyl-d' -"nethoxy triphenylmethane-3"-sulfonic acid and coupling with 2 mols of haphthionic acid.
• Example 20 The dye made by diaaotizing 2- naphthyla1nine-4, li-disulfonlc acid, coupling with meta-toluidine and treating the product with phosgene.
• Example 21 The dye made by tetrazotizing benzicline and coupling with 2 mols of phenol p-sulfonlc acid.
• Example 22 The dye made by tetrazotizing d,e'-diarnino stilbene disulionic acid, coupling with 2 mols of phenol and forming the di-npropyl ether of the product.
• Example 23 The dye made by tetrazotizing e-,ddiarnino stilbene disulfonic acid, coupling with 2 mole of phenol and forming the dibutyl ether of the product.
• Example 2 The dye made by tetrazotizing i,'diamino stilbene .disulfonic acid, coupling with 2 mole of 2,6-dimethyl phenol and forming the di-n-propyl ether of the product.
• the layers need not be colored complementary to their sensitivity, however, but may be colored alternatively with a dye that transmits the color for which the layer is mainly sensitive.
• This film is exposed in a camera or under a suitable color positive or negative.
• it may be exposed to a natural color transparency by a single exposure to tungsten light through suitable correcting filters or by three simultaneous or successive exposures to light transmitted by red, green and blue filters in a suitable ratio of times or intensities. It is then developed in an ordinary black and white developer, washed,
• the silver image is then reconverted to a sliver halide such as silver chloride and the dyes are bleached by treatment in a sodium stannite or sodium hydrosulfite bleach bath. This reduces the silver halide image to metallic silver, and during the same operation, destroys the dye in the region of the silver image so formed.
• the film is then again washed and the silver image is reconverted to silver halide in the same solution previously used for this purpose or in any other suitable bath.
• the film is then fixed in hypo to remove the silver halide and is washed and dried leaving pure dye images in the layers,
• the element is again washed and may then be hardened in a 1 to 20 formalin solution, although this hardening step may be omitted if the emulsions have been suitably hardened before coatmg.
• the silver images produced by the development are bleached to silver chloride by treatment for about ten minutes in the following solution:
• baths of the following composition may be used:
• Pontamine Fast Green 58L for example, a 2% solution of sodium hydrosulfite can be used to bleach the dyes in the presence of the silver chloride image.
• a photographic element containing the dyes reierred to above may be processed according to the method of the present invention to form coloreduccessfully bleached by these aflected the dye in the remaining claims.
• the method -'of forming a colored image in a photographic layer containing a bleachable azo dye uniformly dispersed therein and a rehalogenized silver image, which comprises bleaching the dye in the region of said image with a sodium hydrosulflte bleach bath.
• the method of forming a colored image in a photographic layer containing a bleachable azo dye and unexposed silver halide uniformly dispersed therein which comprises exposing and developing said layer, removing the silver halide without aiiecting the silver image formed by development, reconverting the silver image to silver halide. and bleaching the dye in the presence of said image with a stannit oi alkali-metal to form a colorless dye compound and leave unafiected the dye in the remaining portions of the layer.
• the method of forming a colored image in a photographic layer containing a bleachable aao dye and unexposed silver halide uniformly dispersed therein which comprises exposing and developing said layer, removing the undeveloped silver halide without aflecting the silver image formed by development, reconverting the silver image'to silver halide, and bleaching the dye in an alkaline, reducing bleach bath comprising an alkali metal salt of an acid selected from the group consisting oi stannous acid and hydrosulfurous acid and free of silver halide developing agent in the presence of said image to form a colorless dye compound and leave unaffected the dye in the remaining portions of the layer.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Indole Compounds (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=26247618

Family Applications (2)

Family Applications After (1)

Country Status (3)

Cited By (6)

Families Citing this family (6)

• 1940
  • 1940-10-10 US US360622A patent/US2322001A/en not_active Expired - Lifetime
• 1941
  • 1941-01-21 GB GB812/41A patent/GB546704A/en not_active Expired
  • 1941-08-19 GB GB10577/41A patent/GB551501A/en not_active Expired
• 1942
  • 1942-06-06 US US446054A patent/US2326055A/en not_active Expired - Lifetime
• 1945
  • 1945-08-02 FR FR919792D patent/FR919792A/fr not_active Expired
• 1946
  • 1946-08-23 FR FR54933D patent/FR54933E/fr not_active Expired

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