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
  • G03C5/38—Fixing; Developing-fixing; Hardening-fixing
  • G03C5/39—Stabilising, i.e. fixing without washing out
• • 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
  • Y10S430/166—Toner containing

Definitions

• the invention relates to a method for stabilizing photographic silver images by treatment with an aqueous aftertreatment bath.
• the image tone may shift completely or in areas from black to brown or yellow in the course of time.
• This change in the image tone can be based on a conversion of the silver image into silver sulfide, which can occur, for example, if the washout is insufficient after fixation with sodium thiosulfate.
• a similar disturbing image tone shift occurs when oxidizing gases are exposed to silver photographic images.
• the oxidation of the image silver creates water-soluble silver salts that can diffuse in the material.
• This soluble silver salts finely divided yellow to red-brown colored colloidal silver is formed, or brown colored silver compounds are formed.
• such disturbing changes occur in the finished photographic silver image in the form of so-called microspot defects.
• Microspot defects are understood to mean defects of microscopic size that occur in photographic black-and-white silver halide recording materials, which are characteristically round and generally have a yellow to reddish-brown appearance. These "microspot defects” are also known in the field of silver halide photographic materials as so-called “red spots”, “microscopic spots”, “drying or aging defects” or “microscopic defects or stains”.
• microspots are described in more detail, for example, in a work by RW Henn and DG Wiest with the title “Microscopic Spots in Processed Microfilm: Their Nature and Prevention”, published in the journal “Photographic Science and Engineering, 1963, page 257; furthermore in one work by RW Henn, DG Wiest and BD Mack with the title “Microscopic Spots in Processed Microfilm: The Effect of Iodide”, published in the journal “Photographic Science and Engineering", 1965, page 167 and in a work by CI Pope with the title “Blemish Formation in Processed Microfilm”, published in "Journal of Research of the National Bureau of Standards A. Physics and Chemistry", volume 72A; 1968; pages 251 to 259.
• the microspot defects often occur in a concentrated form trisch.er rings of different sizes, which are particularly noticeable in the halftones of the silver pictures.
• the invention relates in particular to a process for stabilizing a photographically produced silver image by treating the finished silver image with an aftertreatment bath, which is characterized in that the aftertreatment bath contains an amino-1,2,4-triazole of the following formula I. wherein R 1 , R 2 are identical or different and are H, -NH 2 , alkyl, alkenyl, cycloalkyl, aryl, alkoxy, alkylthio, alkylsulfonyl, sulfamoyl, acyl, -SH, or a heterocyclic group.
• R 1 , R 2 are identical or different and are H, -NH 2 , alkyl, alkenyl, cycloalkyl, aryl, alkoxy, alkylthio, alkylsulfonyl, sulfamoyl, acyl, -SH, or a heterocyclic group.
• an alkyl group represented by R 1 or R 2 can be straight-chain or branched and preferably contain 1 to 4 carbon atoms. Examples are methyl, ethyl, isopropyl. Such an alkyl group can also be substituted, for example by hydroxyl, alkoxy, alkylthio, carboxyl, carbalkoxy or amino.
• An alkenyl group is, for example, vinyl or allyl.
• a cycloalkyl group is, for example, cyclohexyl.
• An aryl group is, for example, phenyl, which can optionally be substituted, for example with halogen, alkoxy, alkylthio, acylamino or nitro.
• the alkoxy, alkylthio or alkylsulfonyl groups represented by R 1 or R 2 preferably contain alkyl radicals having up to 4 carbon atoms; preferred examples are methoxy, methylthio, methylsulfonyl.
• a sulfamoyl group is, for example, N, N-dimethylsulfamoyl.
• An acyl radical is preferably derived from an aliphatic carboxylic acid with up to 4 carbon atoms; Acetyl is an example of this.
• a heterocyclic group represented by R 1 or R 2 is in particular a furyl or pyridyl group.
• AT amino-1,2,4-triazoles
• the post-treatment bath to be used in the stabilization process according to the invention consists of a solution of the stabilizing compounds.
• Aqueous solutions are preferred, but solutions in organic solvents or in solvent mixtures of water and organic solvents, such as aliphatic alcohols, dimethylformamide or the like, can also be used.
• the concentration of the stabilizing compounds in the aftertreatment bath can vary within wide limits. It depends on the effectiveness of the used amino-1,2,4-triazole, the material to be stabilized or the desired effect. In general, amounts between 0.5 and 50 g per liter have been found to be suitable. The optimum concentration in the individual case can easily be determined by the expert through routine tests.
• the method according to the invention can be used in the broadest way for photographic silver images, regardless of the special type of production.
• Silver images stabilized by conventional methods by developing and fixing an exposed photographic material are stabilized. These can be conventional halftone images, office copies or microfilms.
• the method according to the invention can also be used to stabilize copies which have been produced by the silver salt diffusion method.
• the processing procedure after the development step may include a stabilizing treatment step in which the unexposed silver halide is wholly or partially removed or converted to a non-photosensitive form .
• Such a stabilizing treatment step can consist, for example, in that the developed photographic recording material, which already contains the silver image but also contains residual silver halide, is subjected to a conventional fixing treatment, e.g. in a processing bath containing an alkali thiosulfate or ammonium thiosulfate, whereby the silver halide is dissolved as a soluble Siberian complex salt from the recording material.
• a "stable" silver image is produced, the stability of which is based on the fact that essentially no light-sensitive silver halide is left in the unexposed areas, and which is referred to in the present context as a finished silver image.
• the stabilizing method according to the invention is to be distinguished from the stabilizing treatment stage mentioned. While the latter serves to remove or convert any remaining silver halide, the stabilization process according to the invention is only used when the silver image produced contains essentially no more photosensitive silver halide.
• the finished silver image which is subjected to the stabilization process according to the invention can, as already mentioned, also be a silver image which has been produced by the silver salt diffusion process. Such a silver image can have been produced in a separate image-receiving layer which may contain silver precipitation nuclei but no silver halide.
• the aftertreatment bath according to the invention therefore does not need to contain any substances which serve to remove residual silver halide.
• the aftertreatment bath according to the invention may, however, contain other additives in addition to the aminotriazole compounds, such as wetting agents, pH-modifying agents and antioxidants, e.g. an alkali metal sulfite or a hydroxylamine salt.
• the aftertreatment bath according to the invention stabilizes the silver image produced by any method by photographic means, so that it is less sensitive to external influences during subsequent storage or storage, in particular to the effects of oxidizing gases.
• the occurrence of this stabilizing effect is also largely independent of the special type of photographic recording material used to produce the silver image, as long as it contains at least one photosensitive silver halide emulsion layer and is developed by any black-and-white development process.
• the light-sensitive silver halide emulsions used in the recording material can contain chloride, bromide and iodide or mixtures thereof as the halide.
• the halide content of at least one layer consists of 0 to 12 mol-X of iodide, 0 to 50 mol-X of chloride and 50 to 100 mol-X of bromide.
• these are predominantly compact crystals, for example cubic or are octahedral or have transitional forms. They can be characterized in that they essentially have a thickness of more than 0.2 ⁇ m.
• the average ratio of diameter to thickness is preferably less than 8: 1, it being true that the diameter of a grain is defined as the diameter of a circle with a circle content corresponding to the projected area of the grain.
• all or individual emulsions can also have essentially tabular silver halide crystals in which the ratio of diameter to thickness is greater than 8: 1.
• the emulsions can be monodisperse or heterodisperse emulsions, which preferably have an average grain size of 0.3 ⁇ m to 1.2 ⁇ m.
• the silver halide grains can have a layered grain structure.
• hydrophilic film-forming agents are suitable as protective colloid or binder for the layers of the recording material, e.g. Proteins, especially gelatin. However, this can be replaced in whole or in part by other natural or synthetic binders. Casting aids and plasticizers can be used. Reference is made to Research Disclosure 17 643 (December 1978), in particular chapters IX, XI and XII.
• the emulsions can be chemically and / or spectrally sensitized in the usual way; they can contain silver halide stabilizers and the emulsion layers as well as other non-photosensitive ones Layers can be hardened in the usual way with known hardening agents.
• Suitable chemical sensitizers, spectral sensitizing dyes, stabilizers and curing agents are described, for example, in Research Disclosure 17643; Reference is made in particular to chapters III, IV, VI and X.
• the recording materials subjected to the stabilization process according to the invention are exposed imagewise, it being possible to use ultraviolet, visible or infrared light or else high-energy radiation for the exposure.
• This is followed by conventional processing to convert the exposed silver halide to image silver, typically by treating the recording medium in an alkaline medium in the presence of a silver halide developer compound which may be contained in one of the layers of the recording medium or in an aqueous treatment bath.
• Inorganic or organic developer compounds can be used. Examples of this are hydroquinone, 3-pyrazolidone, aminophenol and their derivatives.
• Resarch Disclosure 17 643, Chapter XX As a rule, the development is followed by a fixing bath treatment, as a result of which the unexposed and undeveloped silver halide is released from the recording material.
• the stabilizing method according to the invention can be used at any time after the development and generation of the silver image, it unfolds its greatest effectiveness when used as the final treatment step before drying the black and white image. This also means that preferably no further liquid treatment, in particular no washing, follows the stabilizing bath according to the invention. Rather, the stabilizing bath according to the invention is used as an aftertreatment or final bath.
• a useful test procedure is that the aftertreated dried black and white materials are exposed to a very dilute hydrogen peroxide atmosphere at a set relative air humidity of 84%.
• This hydrogen peroxide atmosphere is produced by the hydrolysis of sodium percarbonate Na 2 CO 3 3H 2 O 2 at 84% relative air humidity and room temperature (22-24 ° C).
• the rel. A humidity of 84% is set by a saturated KBr solution.
• the exposed and processed paper strips are suspended vertically in a rectangular glass vessel of approximately 20 liters. The glass vessel is in a tempered water bath to set the temperature of 22-24 ° inside the vessel.
• Amino compounds of other heterocycles such as e.g. the compounds V-3, V-4, V-5, V-6 and V-8 have no stabilizing effect.

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

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• 1986
  • 1986-04-23 DE DE19863613622 patent/DE3613622A1/de not_active Withdrawn
• 1987
  • 1987-04-13 US US07/037,931 patent/US4760015A/en not_active Expired - Fee Related
  • 1987-04-13 DE DE8787105465T patent/DE3762927D1/de not_active Expired - Fee Related
  • 1987-04-13 EP EP87105465A patent/EP0242768B1/fr not_active Expired - Lifetime
  • 1987-04-17 JP JP62093472A patent/JPS62257150A/ja active Pending

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