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
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/46—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein having more than one photosensitive layer
• • 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

• PHOTOGRAPHIC IMAGES This invention relates to photographic images which consist of a silver image and a vesicle image superimposed on the silver image, and processes for producing these images.
• vesicular images comprises light-scattering photographic materials containing a supported or self-supported layer having photolytic compounds dispersed therein, which upon exposure and development by that treatment yields minute vesicles acting as light-scattering centers.
• the unexposed areas of the layer remain transparent.
• the vesicular image therefore appears dark in transmitted light but pale when viewed in reflected light.
• the main disadvantage of vesicular photography is the low light sensitivity of the photographic compounds.
• photographic images can be produced by treating imagewise distributed silver which has been produced in accordancewith common photographic practice with a compound which is decomposed by the silver image with formation of gas, the'gas expanding upon heat treatment to form a vesicular image.
• Photographic images are obtained which consist of metallic silver and an image of minute vesicles superimposed on the silver image.
• the inventive process is highly advantageous since silver salt emulsion layers, especially silver halide emulsion layers, of relatively high light sensitivity can be used for the production of the images.
• the invention provides a greater density of the silver images produced in the photographic silver salt layers by the superimposition of the vesicular image. It is therefore possible to start with layers of a relatively low silver halide content for carrying out the process and then to increase the density of the silver images produced in the layers to images of desired density by the superimposition of a vesicular image. Images of high density can be obtained using light-sensitive silver salt emulsion layers, especially silver halide gelatin emulsion layers, which have a silver content of only about 0.2 g. of silver per square meter. Apart from the fact that a considerable saving in silver is achieved by this process, the combined silver and vesicular images have a great advantage in that they have exceptionally high sharpness.
• the process is particularly advantageous for the production of microfilm and X-ray images.
• the process is carried out using silver halide emulsion layers the binding agent of which is suitable for the production of bubble images.
• Suitable binding agents are synthetic or natural film-forming resins or mixtures thereof.
• the light-sensitive silver halide emulsion layers are processed according to common practice including the steps of imagewise exposure, photographic development and fixing to remove the unexposed silver halide.
• the resulting silver images which may be hardly visible are brought into contact, for example, with hydrogen peroxide (H 0
• the hydrogen peroxide may either act on the silver image as a gas or be introduced into the layer is solution. If the layer is heated with hydrogen peroxide during or after this treatment, a vesicular image is formed in the areas of the silver image.
• the density of the vesicular image depends on the quantity of hydrogen peroxide used, the quantity of silver and the thickness of the layer in which the silver image is produced.
• the heat treatment of the material to produce the light-scattering vesicles should be carried out immediately after or simultaneously with the treatment with hydrogen peroxide.
• the temperature which is used for this heat treatment depends on the properties of the binding agent. Satisfactory results can be obtained at relatively low temperatures, such as 60 to 70 C., but higher temperatures can also be used. If gelatin is used as binder, it is advisable to operate in the presence of limited quantities of water because this promotes swelling of the gelatin an hence vesicle formation.
• the inventive process represents a combination of the conventional silver halide photography and a vesicular process
• a low sensitive fine-grained silver halide emulsion layer which upon conventional processing has a sensitivity of about 13 DIN, can be exposed as an emulsion with a sensitivity of 18 DlN if processed according to the present invention without any loss of details or density in the resulting image.
• the exposed and conventionally processed silver halide emulsion layer is first treated with vapor of hydrogen peroxide and thereafter subjected to water vapor of a temperature of about 50-90 C. for about l-5 seconds. Upon treatment with water vapor the light-scattering minute vesicles are promptly formed.
• alkaline water vapor at a pH of between about 8 and 12. This is easily achieved by adding to the water vapor minor amounts of ammonia or vapors of volatile amines.
• concentration of the alkaline additives is not critical. Generally amounts between 0.1-5 particularly 0.3-1 percent per volume based on the volume of the water vapor having proved sufficient.
• EXAMPLE 1 A photographic silver image obtained as described in example l, but in this case with a density of 0.4, is dipped for a few seconds into ethyl alcohol which contains l percent by weight of hydrogen peroxide, and which has a temperature of C. When using highly hardened gelatin emulsion layers, it is advisable to add about 1 percent by weight of water to this solution.
• the final image consisting of silver and light-scattering minute vesicles has a density of 1.8.
• EXAMPLE 3 A light-sensitive photographic material including a silver iodobromide gelatin emulsion layer (3.5 mol percent of silver iodide based on the total amount of silver halide) which has a sensitivity of 17 DlN as related to conventional processing is exposed as a photographic material which would have a sensitivity of 25 DlN.
• the developed material is fixed in a conventional aqueous bath of sodium thiosulfate.
• the negative silver image of the original is obtained, which is scarcely visible and which is not capable of being copied by conventional photographic processes.
• An image portion which has, for example, a density of 0.3 in the fixed negative is intensified to a density of 1.9 by the inventive processing.
• step 2 If the water vapor applied in step 2 additionally contains 0.5 percent by volume of ammonia, the increase in density is even higher. Image portions which had a density of 0.3 show for example a density of 2.3 after the intensification. In the case of the ammoniacal water vapor the treatment time is reduced to some fractions of a second.
• a photographic material comprising a layer having a binding agent selected from the group consisting of synthetic or natural film-forming binding agents or mixtures thereof, and having an image of metallic silver produced by imagewise exposure, development and fixing of the silver salt emulsion, and containing minute vesicles produced by decomposition of an unstable gas-forming compound under the catalytic action of said metallic silver.
• a process for the production of photographic images consisting of silver and minute vesicles superimposed on the silver in a binder layer including the steps of l. imagewise exposing a layer of a binding agent selected from the group consisting of synthetic or forming binding agents or mixtures thereof and a light-sensitive silver salt and developing the exposed layer to form a metallic silver image therein;

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• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25753438

Family Applications (1)

Country Status (7)

Cited By (7)

Families Citing this family (3)

• 1967
  • 1967-12-23 DE DE1597512A patent/DE1597512C3/de not_active Expired
• 1968
  • 1968-12-12 US US783420A patent/US3615491A/en not_active Expired - Lifetime
  • 1968-12-20 GB GB60699/68A patent/GB1196200A/en not_active Expired
  • 1968-12-23 CH CH1916968A patent/CH501245A/de not_active IP Right Cessation
  • 1968-12-23 FR FR1598076D patent/FR1598076A/fr not_active Expired
  • 1968-12-23 NL NL6818524A patent/NL6818524A/xx unknown
  • 1968-12-23 BE BE725903D patent/BE725903A/xx unknown

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