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
  • G03C7/18—Processes for the correction of the colour image in subtractive colour photography

Definitions

• This invention relates to a process of color correction of subtractive colors in color photographic multilayer materials by forming integral color correction masks in the layer. This is accomplished by reacting the residual color couplers with diazonium compounds derived from an amino salicylic acid.
• the subtractive colors are yellow, magenta and cyan.
• the yellow color coupler is incorporated into the blue-sensitive layer, the magenta color coupler into the green-sensitive layer and the cyan color coupler into the red-sensitive layer.
• the yellow dyestuff corresponds approximately to theoretical requirements necessary for its light absorption, this is not the case with the cyan and the magenta dyestuffs.
• the deficiency of the cyan and magenta color couplers lead to errors in the color reproduction.
• the masking images are formed in the photographic layers in the form of so-called integral color correction masks.
• the masking images which are produced are of a contrast opposite in sign to that of the partial images, since the density of the masking dye in any area of the layer is inversely proportional to the density of the dye of the primary partial image.
• Diazonium salts which are derived from aminosalicylic acids in solid form are quite resistant to shock, and stable in solid and dissolved form. According to a preferred embodiment of this invention the stability and storability can be improved quite considerably by mixing the diazonium compounds with alkyl-naphthalene sulfonic acids. Suitable sulfonic acids are, for example: diisobutyl-naphthalene sulfonic acid.
• the proportions of the diazonium salt and the alkyl naphthalene sulfonic acid is not critical and can be selected in accordance with the properties of the diazonium compound. It has been found that generally from about 0.1 part by weight to about 1 part by weight of the alkyl naphthalene sulfonic acid per part by weight of the diazonium compound are quite sufiicient to obtain the desired improvement of the stability.
• the diazonium salts of aminosalicylic acids are particularly advantageous in that they do not react with the residual color-coupler for the yellow partial image. On the other hand they form a yellow dyestufi with the residual coupler for the magenta-colored partial image and, in the case of substitution by nitro groups, they form a reddish-violet dyestuff with the residual coupler for the cyan partial image.
• diazonium salts derived from aminosalicylic acid of the following formula NHt wherein R hydrogen, alkyl preferably alkyl having up to 3 carbon atoms or nitro.
• Suitable compounds are:
• the mixture is then stirred for another hour and finally the diazonium salt is suction-filtered.
• the salt obtained is first of all washed with 600 cc. of alcohol and then with 300 cc. of ether. About 30 g. of dry diazonium salt are obtained. This is mixed with finely powdered sodium diisobutylnaphthalene sulfonate in a ratio by weight of 1:1.
• the diazonium salt mixture is used either after the usual color processing in a special bath, advantageously at pH 5.5, or it is added to a photographic processing bath, e.g., a bleaching bath, and the operation can in this way be effected without using an additional bath.
• a photographic processing bath e.g., a bleaching bath
• the process of the invention can be applied to any conventional color photographic materials which contain magenta and/ or cyan color couplers capable of reacting with the oxydation products of primary aliphatic amino developers to form a dye.
• color photographic materials which contain the color couplers in a diffusion-resistant form.
• Suitable are color couplers which are substituted by long-chain aliphatic groups and water solubilizing groups and which are distributed homogeneously in the layer, as well as color couplers which are soluble in organic solvents in which they are first dissolve-d and which combination is then dispersed in a finely divided state throughout the emulsion layer.
• Suitable solvents for this purpose are, for example, tries-ters of phosphoric or diesters of phthalic acids.
• Suitable are the usual aromatic amino developers such as p-phenylendiamin type developers, especially the N,N- dialkyl-p-phenylen diamines.
• the process of the present invention can generally be used for compensating the undesired absorption of the dyes produced by reaction of usual cyan or magenta couplers the oxidation products of color-forming developers.
• magenta couplers are, for example, those derived from pyrazolone, in particular l-phenyl-pyrazolone as described, for example, in British Patent No.
• Cyan couplers which can be reacted with the diazonium compounds according to the process of the present invention are particularly phenol or naphthol couplers.
• Example 1 An exposed multilayer color photographic film, of which the blue-sensitive silver halide layer contains 4-stearoyl aminobenzoylacetanilide 3', 5 dicarboxylic acid, the green-sensitive layer contains 1-(4'phenoxy-3'- sulfo)-phenyl-3-stearyl-5-pyrazolone, and the red-sensitive silver halide emulsion layer contains 2'-N-methyl-N- octadecyl-5-sulfo-l-hydroxynaphthoic acid-(2)-anilide, is processed as follows:
• the film is rinsed between the baths and after passing through the masking bath. After this processing, the film contains a yellow masked image in the magenta image layer, in addition to the partial image, and a reddishviolet masked image in the cyan image layer.
• Example 2 Layer structure of the color film and color development bath as in Example 1.
• Example 3 If the diazonium salt of 2-hydroxy-4-methyl-S-aminobenzoic acid is used as masking component and if the processing step is carried out as in Example 1 or 2, the processed film contains a positive yellow masking image and a negative magenta image in the green-sensitive layer.
• Example 4 The diazonium salt of 2-hydroxy-3-amino-S-nitrobenzoic acid is used as masking component. After processing as in Example 1 or 2, a yellow masking image is obtained in the magenta layer and a reddish-violet masking image in the cyan layer.
• Example 5 The diazonium salt of 2-hydroxy-3-amino-5-methylbenzoic acid is used as masking component. Processing as in Example 1 or 2 provides a yellow masking image in the magenta layer.
• Example 6 The diazonium salt of 2-hydroxy-5-aminobenzoic acid is used. After processing as described in Example 1 or 2, a yellow masking image is obtained in the magenta layer.

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

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Citations (2)

• 1964
  • 1964-01-30 DE DEA45117A patent/DE1195163B/de active Pending
  • 1964-12-29 US US421988A patent/US3274001A/en not_active Expired - Lifetime
• 1965
  • 1965-01-08 CH CH26865A patent/CH442983A/de unknown
  • 1965-01-29 BE BE659015D patent/BE659015A/xx unknown

Patent Citations (2)

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