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
  • G03C7/392—Additives
  • G03C7/39208—Organic compounds
  • G03C7/39212—Carbocyclic
  • G03C7/39216—Carbocyclic with OH groups

Definitions

• This invention relates to color photography and particularly to a method for preventing the formation of color fog or stain in photographic emulsions.
• colorforming or coupler compounds combine with the development product of aromatic amino photographic developers to produce dyes.
• the color formers or couplers may be added directly to the emulsion layers or may be incorporated in the developing solution as described in Fischer U. S. Patent 1,102,028, granted June 30, 1914, or they may be incorporated in a waterpermeable medium which is insoluble in the carrier for the sensitive silver salt as described in Mannes and Godowsky U. S. Patent 2,304,940, December 15, 1942, and Jelley and Vittum U. S. Patent 2,322,027, granted June 15, 1943.
• a difiiculty frequently encountered in these processes is the formation of color fog or stain.
• dye fog is frequently formed in the emulsion layer. This is because the developing agent has been oxidized to some extent by the action of the air and the oxidized developertends to couple with the color-forming compound at places in the photographic material where no silver image is produced. It is well known that in these processes the dye should be formed only where the silver halide is reduced to metallic silver, thereby oxidizing the developing agent to a form which couples with the color former. Once the developing agent is oxidized, it couples immediately with the color former whether a photographic image is present or not.
• Aerial oxidation of the developer or oxidation by means other than the photographic image therefore converts the developer to a form which will immediately react with the color former to produce a color fog or stain.
• This eifect is especially noticeable in materials having couplers incorporated in the sensitive layer since there is no coupler in the developing solution to react with any developing agent which is oxidized by the action of the air. Fog or stain arising from these causes is not readily controlled by the same procedures used to control silver fog.
• Antistain agents for direct incorporation in photographic emulsion layers must fulfill certain requirements such as the following:
• an object of the present invention to provide antistain agents which are easily compatible with and non-difiusing in the colloid of the photographic layer in which they are incorporated.
• a further object is to provide antistain agents which are non-diffusing in the photographic layer and which are strong enough reducing agents to react rapidly with oxidized color developer.
• a further object is to provide antistain agents which do not form highly colored oxidation products when the material containing them is put through an oxidizing bath.
• the compounds which we propose to use have the structure "ice H in which R represents hydrogen or an alkyl or aralkyl group and R represents an alkyl, aralkyl or acylamino group.
• the alkyl group may be a simple alkyl group such as methyl, ethyl, propyl, butyl or amyl or a longchain alkyl group such as undecyl, hexadecyl or octadecyl.
• the aralkyl group may be a benzyl or substituted phenethyl, phenylpropyl, etc.
• the compounds are sulfonated by incorporating a sulfonic acid radical either in the hydroquinone ring or in one of the substituent radicals attached to the hydroquinone nucleus. If the compound is to be non-migratory as, for example, when its action must be restricted to one layer of a multi-layer material, R must be larger than C10 when R is hydrogen. If the wandering of the antistain agent does not need to be restricted to a single emulsion layer, R and R may be lower alkyl or aralkyl groups.
• the compounds are incorporated ordinarily as a soluble salt, such as the sodium, potassium, lithium or ammonium salt.
• Antistain agents useful according to our invention are:
• hydrophilic antistain agents offer the advantage that they can be added directly to the emulsion melt befort coating without requiring the preparation of a dispersion.
• Our antistain agents may also be used in emulsions of the type described in Mannes and Godowsky U. S. Patent 2,304,940, and Jelley and Vittum U. S. Patent 2,322,027 where the coupler is present in a dispersed hydrophobic solvent.
• the presence of the antistain agent in the dispersed phase causes a reduction in the stability in the developed dye image. This situation exists in certain of the layers containing cyan and yellow-forming couplers.
• antistain agents of our invention may also be used in non-sensitive overcoating or filter layers such as the colloidal silver interlayer.
• EXAMPLE 1 brought to 200 cc. To this solution was then added a agent.
• the antistain agent 0.1 g. of potassium n-hexadecylhydroquinone-xsulfonate, was dissolved in 2.5 cc. of water and this solution was added to the coupler-emulsion mixture before coating on a suitable support.
• the resulting coating gave a clear cyan dye image on color development with distinctly lower stain than was obtained with a similar coating containing no antistain agent.
• the antistain agent e. g., 0.1 g. of potassium sec.-undecylhydroquinone-x-sulfonate, was dissolved in a minimum amount of water (about 2 cc.) and added to the coupler-emulsion mixture before coating on a suitable support.
• the resulting coating gave a bright yellow dye image on color development, and showed a marked reduction in stain over a similar material prepared without the antistain agent.
• a complete three-color coating may be prepared as follows EXAMPLE 4
• a multi-layer coating was prepared as follows: On the support was coated a red-sensitized emulsion layer containing a cyan coupler prepared as in Example 2. Over this was coated a thin gelatin interlayer, and then a layer of green-sensitized emulsion containing the magenta coupler, 1-[(p-tert.butylphenoxy)-phenyl]-3-[a-p tert.- butylphenoxy) -propionyl-amino]-5-pyrazolone, and the antistain agent di-isoctylhydroquinone.
• This magenta layer was prepared according to the general methods given in U. S.
• the compounds of our invention are prepared by treating a hydroquinone with a suitable unsaturated hydrocarbon, sulfonated or not. If the unsaturated hydrocarbon is unsulfonated the resulting compound is sulfonated, or oxidized to a quinone which is then sulfonated by addition of sodium bisulfite."-- - The-following example is typical.
• the oil was then taken up in 200 cc. of ether and Washed twice with water. After filtration and evaporation, the residual oil was twice fractionally distilled under vacuum. The final product weighed 31.5 g. (24%) 170.5 163-166 C.
• the reaction mixture was stirred for 1 hour longer and then concentrated to dryness under vacuum on a steam bath.
• the residue was dissolved in 10 cc. of water, and 2.0 g. of potassium chloride was added.
• the semi-solid potassium salt of the sulfonic acid separated as the potassium chloride dissolved.
• the aqueous layer was decanted and the residue redissolved in 10 cc. of water and treated with 2.0 g. of potassium chloride. This process was repeated once more.
• a pasty solid resulted.
• the solid was dissolved in 15 cc. of acetone, leaving an insoluble inorganic material which was removed by filtration.
• the clear solution was concentrated on a steam bath, giving a clear resinous material which showed a tendency to harden.
• the residue was placed in a vacuum desiccator over sulfuric acid overnight, forming hard lumps.
• the lumps were pulverizzed and replaced in the desiccator for final drying.
• the yield was 2.2 g. (57.9%) of very hygroscopic power.
• the reducing agents of our invention are used in the emulsion or other layer in quantities ranging from 0.07 grams to 4.3 grams per liter of emulsion or gelatin solution. These values are, however, merely illus trative.
• the antistain agents of our invention may be incorporated in a processing solution such as a prebath, first developer bath, or color-forming developer used with color film which is developed with a primary aromatic amino developing agent.
• a processing solution such as a prebath, first developer bath, or color-forming developer used with color film which is developed with a primary aromatic amino developing agent.
• the antistain agents which we propose to use are soluble in alkaline solution and would serve to react with any oxidized developer in the solution but would not diffuse into the film, because of their complex structure.
• a color-forming photographic element having an emulsion of reduced color fogging tendency comprising a support having thereon at least a silver halide emulsion layer containing a non-diffusing coupler compound, at least one layer of said element containing a non-diffusing antistain agent of the following structure:
• R is selected from the class consisting of alkyl groups having 4 carbon atoms, benzamido alkyl groups, benzamido benzamido groups, benzamido benzamido alkyl groups, and benzamido benzamido phenyl carbamyl alkyl roups.
• R is selected from the class consisting of alkyl groups having 4 carbon atoms, benzamido alkyl groups, benzamido benzamido groups, benzamido benzamido alkyl groups, and benzamido benzamido phenyl carbamyl alkyl roups.
• g 2 The method of preventing the formation of color fog in a layer of a photographic element containing a non-diffusing color coupler, said element comprising a support having at least one silver halide emulsion thereon, which comprises incorporating in a layer of said element a non-diffusing antistain agent of the following
• R is selected from the class consisting of alkyl groups having 4 carbon atoms, benzamido alkyl groups, benzamido benzamido groups, benzamido benzamido alkyl groups, and benzamido benzamido phenyl carbamyl alkyl groups, exposing said emulsion and developing it with a primary aromatic amino developing agent.
• a color-forming photographic emulsion having reduced fogging tendency comprising a silver halide emulsion having incorporated therein a non-diffusing coupler compound and a water-soluble salt of a non-diffusing antistain agent having the formula:
• a color-forming photographic emulsion having reduced fogging tendency comprising a silver halide em-ulsion having incorporated therein a non-difiusing coupler compound and a water-soluble salt of a non-diffusing antistain agent having the formula:

Landscapes

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

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22995431

Family Applications (1)

Country Status (4)

Cited By (22)

Families Citing this family (1)

Citations (8)

• 0
  • BE BE516242D patent/BE516242A/xx unknown
• 1951
  • 1951-12-15 US US261914A patent/US2701197A/en not_active Expired - Lifetime
• 1952
  • 1952-12-15 FR FR1080507D patent/FR1080507A/fr not_active Expired
  • 1952-12-15 GB GB31797/52A patent/GB731301A/en not_active Expired

Patent Citations (8)

Also Published As

Similar Documents