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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/40—Chemically transforming developed images
  • G03C5/44—Bleaching; Bleach-fixing
• • 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
• • 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
  • G03C7/42—Bleach-fixing or agents therefor ; Desilvering processes
  • G03C7/421—Additives other than bleaching or fixing agents

Definitions

• ..G03c 7/00, G036 5/50, G036 5/32 Pr comprises treating the photographic material [58] Field 61 Search ..96/20, 53,61,- 59, 60 with a acid bath free from that form sparingly 1 1 soluble silver salts and which bath contains an'oxidant [56] R fe Cit -d and a complexing agent.
• the oxidant has a standard redox potential of at most +0.8 Voltsand the com- UNITED STATES PATENTS plexing agent has a silver complex stability constant of 2,304,987 12/1942 Young; .Q ..96/60 109 (liter/mole)?
• the primarily developed silver must be removed without attacking any residual, undeveloped silver halide since in a further process step the latter is developed to the positive silver image.
• This can be done with oxidation baths which convert the silver into a soluble silver salt which can diffuse out of the photographic layer, for example, a sulphuric acid solution of potassium dichromate'orpotassium permanganate, for
• the oxidation of silver and .the washing out of the silver halide may-be carried out in separate baths by first oxidizing the silver and then dissolving the silver halide.
• oxidation of the silver may also be carried out with a solution that converts the silver into a sparingly soluble silver salt, forexample a hydrochlo-' ric acid solution of copper(ll)chlori de or a solution of potassium-iron(lll)cyanide since the sparingly soluble silver salts formed remain in the layer and are removed during the subsequent fixing operation.
• oxidation baths such as dichromate-sulphuric acid, cannot be used since theseoxidants also decompose other componentspresent in thephotographic layer.
• Suitable oxidants are copper(ll)salts or more especially quinones and iron(lll)salts. Particularly good resultsare obtained with iron(lll)salts, for example iron(lll)perchlorate,
• iron(lll)nitrate or ammonium iron(lll) sulfate According to this invention only anions that do not form sparingly soluble silver salts can be used.
• the oxidation potential of these oxidants must be below +0.8 Volt,
• the standard redox potential of the following elec rro-chemical reactions is, for example:
• complexin'g'agents are those which display a silver complex stability constant of from 10" to 10 (liter/mole).
• com plexing agents having a silver complex stability constant within this range are water-solubleunsaturated compounds,for example allyl alcohol,initriles, for example acetonitrile, certain heterocyclic amines, for example pyrazine, and thioethers'
• Especially suitable complexing agents are those having a silver complex stability constant of from 10 to 10 (liter/moleY, especially water-soluble thioethers, and preferably monothiosethers.
• water-soluble aliphatic monothioethers which corresponds to the formula v I r'- r 2 2 inwhich R, and R, whichmay be the same or different each represent an alkyl group containing from one to threecarbon' atoms, and X and X each represent a hydrogen atom or a hydroxyl or carboxyl group.
• Suitable water solublethioethers are, for example:
• water-soluble thioethers in "which R and R are aromatic or heterocyclic residues, for example the disodium saltof di-(para-sulphophenyl)-sulphide, 'or the free acid thereof.
• cyclic water-soluble thioethers 'such as thiophene- 2,5-dicarboxylic acids which correspond, for example, to the formula in which X, and X have the meanings defined above.
• the pH value of the treatment bath should advantageously be below 6.
• Acids suitable foradjusting the pH value are, for example, sulphamic acid, sulphuric acid, oxalic acid, citric acid, perchloric acid, nitric acid and other acids capable of forming readily soluble silver salts.
• the salts of the oxidant for example copper sulphate, form acid solutions'in water it is not necessary to add additional acid to the treatment bath.
• the proportions of the individual constituents may be varied within wide limits. It is also possible to use mixtures containing more than one of each of the acids, oxidants and complexing agents.
• the bath may further contain conventional additives, such as surface-active- I colored image by diffuse light and second development 54, pages 264 276 [1958] andE. Larsson in the book or by development in the presence of a fogging agent, or by sulphidation. i
• the invention is of special importance in carrying out the silver dye bleach-negative-positive process.
• a material that contains photosensitive silver -halide and a dyestuff; On exposure and development a silver image is formed whose gradation is the opposite of that of the master (negative silver image).
• a color gradation is achieved which is opposite to that of the silver image, that is to say equal to that of the master.
• a positive color image of a positive master is obtained.
• a reversal f to metallic silver and then decomposing the dyestuff the metallic silver and the sparingly. soluble silver salt are contained in the same silver emulsion layer. This is the case whenever the metallic silver is distributed to form an image, especially inreversal processes where a primarily .developed silver image isdissolved and the residual silver salt image is converted into a black or depending on the amount of silver present in the layer, and removing the primary silver image by means of an acid bath which is free from anions that form sparingly soluble silver salts and which contains an oxidant and a complexing agent capable of forming with silver complexes of little stability;
• the temperature of the silverbleaching bath and the treatment time may be varied within wide limits without incurring a loss of undeveloped silver halide.
• the present process is applicable to the treatment of both single-layer and multilayer color materials, of materials for viewing in incident light and transparencies, of mixed grain emulsion layers and of materials with incorporated capsules.
• a rapid reversal process can be carried out with a metarial which contains acid, oxidant and complexing agents in crushable pods.
• Another variant starts from a material that contains oxidant and complexing agents in-pods which disintegrate only when they come into contact with an acid bath.
• the process according to the present invention is of special value in connection with reversal processes but the invention is also suitable for other processes in which metallic silver (such as developed image silver, latent image nuclei or colloidal silver) is dissolved without affecting any sparingly soluble silver salts present (which are present in the same grain, in the same layer or in another layer).
• metallic silver such as developed image silver, latent image nuclei or colloidal silver
• EXAMPLE 1 Two strips of a blue-sensitized emulsion layer on a cellulose triacetate base, containing 0.7 g of silver bromide and 0.12 g of a yellow dyestuff of the formula are chosen according a nous n 5,0 11 per square meter, are exposed under a stepped wedge. The exposed strips are developed with a commercial para-methylaminophenol sulphate/hydroquinone developer and the development process is stopped with a 3 percent solution .of acetic acid. After having been washed in water for 1 minute, one strip is treated for 3 minutes'a'nd the other strip for 10 minutes with a solution'of thefollowing composition to remove the metallic silver left in the layer after the first development:
• strips are treated for 6 minutes with a commercial p-' methyl-aminophenol-sulphate/hydroquinone Hydrochloric acid, 37% strength 70 ml potassium bromide 50 g thiourea 80 g 2-amino-3-hydroxyphenazine 5 mg water, to l liter.
• Potassium iron(lll)cyanide 75 g potassium bromide l5 g primary sodium phosphate monohydrate [0 g g sodium acetate trihydrate I 5 g glacial acetic acid l0 ml water, to Y l liter.
• strips are then rinsedin water for 1 minute and fixed with an acid'thio'sulphate solution in the known manner. Both strips'carry identical yellow images of the stepped wedge used for the exposure, which are negative with respect to the master.
• EXAMPLE 4 Instead of the bath described in Example 2 a solution of the following composition is usedr lron(lll)p crchlorate nonahydrate 52 g perchloric acid, strength 150 g disodium salt of di-(p-sulphophenyl)-sulphide g water, to 1 liter pH value: 0.6.
• a photographic tripack material which carried on a allyl alcohol 8 b l 1) I (l l water, to 20 transparent ase a red-sensitized Sl ver rorm eemu pH value: 0.35.
• the silver halide left in the layer is then reduced to metallic silver with the developer used in Example 1.
• the resulting silver image of the grey wedge used for the exposure is a positive reproduction of the master.
• EXAMPLE 14 A strip of an emulsion layer on an opaque cellulose triacetate base, sensitive to red light, which carries per square meter of base 0.7 g of silver bromide and 0.115 g of the cyan dyestuff of the formula (4) is exposed under a stepped wedge and then processed as described in Example l, except that the metallic silver left in the layer after the first development is removed with a bath of the following composition:
• Ammonium-iron(lll)sulphate dodecahydrate 60 g 2N-sulphuric acid 100 ml pyrazine 50 g 1 liter water, to
• the resulting cyan-colored image is a negative of the stepped wedge used for the exposure.
• Example 14 The process described in Example 14 is used, except that the metallic silver formed after the first development is removed with a bath of the following composition:
• lron(lll)nitrate nonahydrate 40 g 2N-nitric acid 100 ml pyrazine 50 8 water, to 1 liter pH value: 0.8.
• Example 14 As in Example 14 a cyan-colored image is obtained which is a negative reproduction of the stepped wedge used for the exposure.
• a process as claimed in claim 1, wherein the complexing agent is a monothioether of the formula in which R, and R which may be the same or different, each represents alkyl having at most three carbon atoms, and X, and X which may be the same or different, each represents hydrogen or hydroxyl or carboxyl.

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• General Physics & Mathematics (AREA)
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Citations (9)

• 1969
  • 1969-07-30 CH CH1160569A patent/CH511456A/de not_active IP Right Cessation
• 1970
  • 1970-07-21 US US00056945A patent/US3716362A/en not_active Expired - Lifetime
  • 1970-07-21 CA CA088,675A patent/CA942559A/en not_active Expired
  • 1970-07-21 GB GB3530370A patent/GB1324515A/en not_active Expired
  • 1970-07-23 FR FR7027157A patent/FR2055511A5/fr not_active Expired
  • 1970-07-29 NL NL7011234A patent/NL7011234A/xx unknown
  • 1970-07-29 BE BE754080D patent/BE754080A/fr unknown
  • 1970-07-29 DE DE19702037684 patent/DE2037684A1/de active Pending

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