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
  • G03C5/60—Processes for obtaining vesicular images
• • 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
• • 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
  • G03C5/50—Reversal development; Contact processes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/144—Hydrogen peroxide treatment

Definitions

• the invention relates to a process for the production of photographic images by imagewise decomposition of peroxide compounds, a visible image being produced either physically by imagewise production of gas bubbles or chemically by a color-producing oxidation reaction with a suitable reaction component.
• the above mentioned process for the production of photographic images may also be carried out with layers which contain substances which on exposure to light form catalase active or peroxidase catalysts.
• Suitable substances of this kind are e.g., certain complex compounds of heavy metals ofGroups Vlh, Vllb or VIII of the Periodic Table of elements with a mono-basic or higher basic carboxylic acid. Compounds which split off iodine ions on exposure to light have the same effect.
• Light-sensitive photographic materials used for this purpose may contain, uniformly distributed in them, catalase-active or peroxidase-active enzymes such as catalase, peroxidase, hemoglobin or hemin which are inactivated in the image areas when exposed to actinic light.
• catalase-active or peroxidase-active enzymes such as catalase, peroxidase, hemoglobin or hemin which are inactivated in the image areas when exposed to actinic light.
• the images obtained with these materials are direct positive images.
• a disadvantage of this direct positive process is the relatively low light sensitivity of these catalase active enzymes.
• a process of this type comprises the following process steps: imagewise exposure of the silver halide emulsion layer, black and white development to produce a negative silver image, bleaching of the silver image, uniform reexposure of the silver halide in the emulsion layer, reverse second development to produce the positive silver image, and production of a bubble image or of a dye image by decomposition of peroxide compounds on this positive silver image.
• the said positive image being rendered visible by the presence of substances which accelerate the decomposition of peroxides either physically resulting in the development of a bubble image or chemically by an oxidation reaction with a color producing reaction component.
• the most suitable silver halide emlusion layers for the process of the invention have a low silver content but a high packing density of the silver halide.
• the silver application of these layers which are preferably used may be about 0.01 l g of silver in the form of silver halides per m
• the packing density of the silver halide in these layers, i.e., the proportion of silver halide in the layer, should be at least percent, i.e., the layer may contain at least 1 part by weight of silver halide per 1 part by weight of binder.
• the light-sensitive layers may be covered with protective layers of gelatin or other binders.
• silver halide in silver bromide although silver chloride layers may of course, also be used, and the silver halides may contain a certain amount of silver iodide, up to about Mols percent.
• the layer After exposure, the layer is photographically developed by the usual processes.
• the usual developing agents are suitable for this purpose.
• the peroxide compound e.g., with hydrogen peroxide
• the peroxide compound decomposes very rapidly in those areas where a negative silver image has been produced by the photographic development process. This decomposition of peroxide can be recognized by the vigorous evolution of oxygen in those parts of the layer which have a high silver content.
• the peroxide compound In the unexposed areas of the layer, on the other hand, the peroxide compound is absorbed by the layer and remains practically undecomposed. It remains available for the subsequent production of the positive image.
• a certain amount of decomposition of peroxide is also required to render the positive image visible. Suitable measures are therefore required to ensure that a certain amount of decomposition of peroxide compound will also take place in the unexposed areas of the layer. This can be achieved in known manner by adding to the light-sensitive layers, in a uniformly distributed form, substances which accelerate the decomposition of peroxide compound. However, despite the presence of these substances the peroxide compound must be decomposed much more rapidly in the exposed areas which contain the negative silver image than in the unexposed areas which do not contain negative silver.
• Active charcoal or organic substances such as catalase active or peroxidase active enzymes.
• the light-sensitive silver salts are preferably dispersed in a binder in the lightsensitive layers.
• the usual binders used for photographic silver halide emulsion layers are suitable, especially proteins and particularly gelatin, but gelatin may be partly or completely replaced by natural or synthetic film-forming binders or inorganic structure-forming substances such as silica gel.
• Suitable organic filmforming polymers are e.g., polyvinyl acetate, partly saponified polyvinyl acetate, polyvinyl alcohol, cellulose esters such as cellulose acetate, carboxymethyl cellulose and alginic acid or its derivatives such as salts, amides, esters or the like.
• Inorganic peroxide compounds e.g., perborates, percarbonates, perphosphates or persulfates are suitable for the process according to the invention but the most suitable peroxide compound is hydrogen peroxide.
• Organic peroxide compounds may also be used, e.g., benzoyl peroxide, percarbamide and addition compounds of hydrogen peroxide and aliphatic acid amides, polyalcohols, amines acyl-substituted hydrazines etc.
• Hydrogen peroxide is preferred on account of its high activity and the ease with which it can be handled in the form of aqueous solutions.
• the peroxide compound is preferably used in the form ofa solution.
• Hydrogen peroxide for example may be used also in vapour form.
• the process of rendering the positive image visible by decomposition of the peroxide may be effected by physical or chemical means.
• the developed oxygen may be rendered visible in the form of a bubble image by the process described in British Patent Specification No. 1,196,200.
• the peroxide compounds may be decomposed in the presence of reactants for a color producing oxidation reaction. Processes of this type have been described in US. Q LLNQLLQZwQ
• the exposed and developed layer is heated after the treatment with the peroxide compound and the necessary time of decomposition on the image silver. A bubble image is then formed in the areas where the peroxide compound has been left intact.
• the intensity of the vesicle image depends on the quantity of hydrogen peroxide used and the quantity of decomposition nuclei.
• the heat treatment of the material to produce the visible bubbles should be as brief as possible.
• the temperature employed in this treatment depends on the properties of the binder. Satisfactory results can be achieved at relatively low temperature of about 60 to C but higher temperatures may also be employed if this is necessitated by the softening point of the binder. If gelatin is used, which is the preferred binder, it is advisable to carry out the treatment in the presence of small quantities of water because this promotes swelling of the gelatin and hence bubble formation. The same applies to other binders which swell in the presence of water.
• Rendering the image visible may be achieved also by a chemical method.
• the process is performed in the presence of reaction components for a color producing oxidation reaction. Suitable processes lene, 1,8-diamino naphthalene, benzidine, 2,2- diamino naphthalene, 4,4'-diaminophenyl, 8- hydroxyquinoline, S hydroxyqriinoline, 2-
• amino, hydroxyl or aminohydroxy compounds may be substituted, e.g., with halogen, alkyl, aryl, alkoxy, sulfonic acid, nitro, keto, carboxylic acid or carbonamide groups.
• mixtures of several such compounds will give rise to much more intense dye formation on oxidation than the individual components.Thus for example a mixture of o-phenylenediamine and pyrocatechol produce a more intense dye-forming reaction. Even components which do not yield dyes on oxidation when used alone, e.g., tetrabromohydroquinone or tetrabromopyrocatechol, may intensify the formation of dyes when they are added to other hydroxyl, amino or aminohydroxy compounds.
• leuco dye compounds and vat dyes which may be oxidized to dyes may, of course, also be used.
• K'unstliche organische Farbstoffe und occur in the vicinity of H. R. SCHWEIZER, Springer-Verlag, Berlin-Gettingen-Heidelberg (1964), pages 250 and 320.
• Oxidizable organic compounds of the type which yield the image dye only in a subsequent reaction with other compounds are also suitable for the process of the invention.
• any reaction systems which undergo an oxidizing coupling reaction to yield dyes may be used.
• lsocyclic and heterocyclic hydrazines may also be coupled with suitable components to yield dyes by oxidation (see e.g., H. HUNIG et al., Angew, Chem. (1958) 215; S. HUNIG, Chimia 15 (1961) 133 and Angew, Chem. 74 (1962) 818).
• the color-producing photographic developer substances are oxidized catalytically by the peroxide compounds in the presence of the catalysts which is distributed imagewise. Their oxidation products may then react with-known photographic color couplers which are also present to yield dyes.
• Suitable color couplers for this purpose are e.g., cyan couplers of the phenol or naphthol series, magenta couplers of the indazole series and yellow couplers of the benzoyl acetanilide series.
• reaction time required for the hydrogen peroxide compound i.e., the length of time between the treatment of the developed layer with the peroxide compound and the rendering visible of the positive image
• the time required for sufficient decomposition of the peroxide compounds in those parts of the layer which contain the negative image silver depends primarily on the concentration of the peroxide and the catalytic activity of the negative silver image. The times required for any given peroxide compound and silver halide emulsion can easily be determined by simple laboratory tests..
• the maximum density and the gradation of the positive image can be modified by altering the length of waiting time between the peroxide treatment and the production of the positive image.
• the individual steps of the process may be accelerated by increasing the temperature. This increase in temperature in addition increases the sharpness of the image.
• the layer is then passed for 10 seconds through the following bath after a brif washing:
• This process produces a blue-black, positive image of the original.
• Example 2 100 ml of a highly sensitive AgBr emulsion are stirred into 500 ml ofa 10 percent aqueous solution of the following cyan color coupler:
• Example 1 For the other emulsion additives see Example 1.
• the mixture is cast to form a layer about 15 p. in thickness.
• Silver application approximately 0.6 g of silver in the form of silver halide per m
• a protective gelatin layer about 5 p, in thickness is then cast over this layer.
• the layer is exposed imagewise in a conventional sensitometer for l/l00th second behind a grey step wedge and then developed for 15 seconds at 35 C in the following developer:
• Solution 1 50 g of Na SO O in 500 cc of H 0
• Solution 2 25 g of K,,Fc(CN) in 500 cc of H 0 (the two solutions are mixed before use) the layer is washed and dried.
• a cyan positive image of the original to which the layer has been exposed is obtained.
• nazq sstie 9rvxraz series are suitable for use as magenta couplers and those of the benzoyl acetanilide series are suitable as yellow couplers.
• Example 3 0.5 cc of a colloidal silver sol prepared as described in The Theory of the Photographic Process by C. E. K. MEES, 1st Edition, MacMillan Co., New York (l942), page 565 are added to cc of a silver chlorobromide gelatin emulsion which has a steep gradation (60 Mols percent of AgBr). Suitable quantities of Au, Pt, Pd, Os, lr and other noble metal sols may be added instead of this silver sol. For the other emulsion additives, see Example 1.
• the mixture is cast to form a layer of about 15 p. in thickness.
• Total silver application approximately 2.0 g of silver in the form of silver halide per m Over this is cast a protective gelatin layer of about 8 u in thickness.
• the layer is exposed imagewise as in Example 2 and then developed for 15 seconds at 35 C in the following developer:
• the layer is heated to about 80 C with infrared radiation for 30 seconds and then treated for 15 seconds at 35 C with Bath Ill: 20 g of 1.7-dihydroxy naphthalene 40 g of pyrocatechol made up to 1 litre with H O adjusted to pH 12 with NaOH To stabilize and bleach the negative silver, the layer is finally passed for 10 seconds through the following bath after a brief washing:
• Example 4 A photographic layer as described in Example I (after imagewise exposure and fogging development as described in Example 1) is dipped for seconds into the following peroxide bath:
• gas bubbles may be intensified by the addition of hydrazine hydrate to the above mentioned peroxide bath.
• the gas bubbles in that case consist not only of oxygen but of mixture of oxygen and nitrogen.
• the fogging development may be replaced by a nonfogging development if the layer used has been prepared from 1 litre of silver halide emulsion 5 ml of a 0.1 percent catalase solution (as catalase active catalyst).
• a process for the production of positive photographic images by imagewise exposing a light sensitive silver halide emulsion layer on a support, developing the exposed emulsion to provide metallic silver, applying to the exposed and developed emulsion a peroxide compound and decomposing the peroxide on the emulsion, wherein the improvement comprises providing in the emulsion a uniformly distributed catalyst selected from the group consisting of catalase active and peroxide active catalyst, which catalyst accelerates the decomposition of the peroxide to release oxygen at a slow rate, decomposing the peroxide in the exposed areas under the catalytic action of the metallic silver at a high rate of decomposition, catalyzing the decomposition of the applied peroxide in the unexposed areas to release oxygen at a slower rate than said decomposition at the metallic silver so that peroxide compound at the negative silver image is decomposed and a positive image is formed by the decomposition of the remaining peroxide compound in the unexposed areas.
• a uniformly distributed catalyst selected from the group consisting
• the silver halide emulsion layer contains at least one part by weight of silver halide per one part by weight of binder.
• catalase active and/or peroxidase active catalysts are noble metals of Groups lb or VIII of the Periodic Table.
• catalase active and/or peroxidase active catalysts are complex compounds'of heavy metals of Groups Vlb, Vllb or VIII of the Periodic Table.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=5788268

Family Applications (1)

Country Status (8)

Cited By (15)

Families Citing this family (1)

• 1970
  • 1970-11-17 DE DE19702056360 patent/DE2056360A1/de active Pending
• 1971
  • 1971-11-10 BE BE775134A patent/BE775134A/nl unknown
  • 1971-11-12 CA CA127,472A patent/CA969408A/en not_active Expired
  • 1971-11-15 US US00198961A patent/US3776730A/en not_active Expired - Lifetime
  • 1971-11-15 IT IT54091/71A patent/IT944934B/it active
  • 1971-11-17 GB GB5328071A patent/GB1355670A/en not_active Expired
  • 1971-11-17 FR FR7141202A patent/FR2114822A5/fr not_active Expired
  • 1971-11-17 CH CH1672471A patent/CH566571A5/xx not_active IP Right Cessation

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