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
  • G03C5/383—Developing-fixing, i.e. mono-baths

Definitions

• This-invention relates to a developer capable of pre venting formation of colored sludge, which has been often a greattrouble for photographic treatment with the so-called monobath developing-fixing agent con taining thiosulfates asa fixing agent and a liquid developer containing a water-soluble, silver complexforming agent.
• the mono-bath developing-fixing agent has been applied not only to the development of films for the general pictures, but also to the development of microfilms or to a rapid treatment for regenerating a print from the developed negative, that is, a printing of necessary portions of investigating the negative on a reader printer.
• the mono-bath treatment is particularly effective, because it is quite enough to use only a single bath.
• these two baths are mixed together, where not only brown contamination is brought about, but also it is inconvenient to exchange the solution.
• the stabilization bath is strongly acidic and a thiocyanate is used in the stabilization bath. Therefore, the metallic parts of an apparatus is liable to be corroded. Furthermore, the finished print is often liable to be faded. These are the disadvantages of the two-bath type, developing and fixing treatment.
• the mono-bath developing-fixing treatment has also disadvantages.
• the greatest disadvantage is a formation of a large amount of colored sludges during continuous photographic treatment. Such formation not only makes the solution dirty, but also the colored sludges stick to surfaces of prints and films and makes the surfaces dirty. Therefore, the solution must be often exchanged or filtered.
• the colored sludge is formed according to the following manner: silver halide in a film or photographic paper to be treated is dissolved and entered into a developer solution by action of a silver complex-forming agent contained in the solution, and the silver halide is reduced to silvercolloid by the developer. The silver colloid is formed in the solution.
• a portion thereof is coagulated and settled, but the most portion thereof is suspended in the solution in a form of blackish brown, dirty sludge floc.
• the formation of such colored sludge can be retarded by lowering a temperature of the developer solution, but in that case the developing as well as fixing speed is also retarded. Thus, it is not practical to lower the temperature.
• the proposed method is not directed to the prevention of formation of the sludge itself, and thus sludge is successively formed and a satisfactory effect cannot be attained.
• a vigorous stirring'is effected of filtration of the solution is not carried out, the sludge is liable to stick to the surface of the print and the sticked sludge is hard to remove.
• the proposed method such new disadvantages are encountered. Therefore, it is necessary to prevent formation itself of the sludge to avoid the serious influences by the colored sludge.
• an action enough to prevent the formation of colored sludge is attained by adding an increased amount of the additive to the solution, but in that case the developing speed is extremely retarded with no exception, and the desirable density of developed silver is not obtained.
• the action to prevent the formation of colored sludge can be maintained for about a few days, but the maximum density of developed silver is extremely lowered, for example, the optical density 1.3 at the non-addition of the additive falls down to 0.6. Thus, the solution becomes unpractical.
• An object of the present invention is to provide a developer containing an additive capable of preventing' a formation of colored sludge due to silver colloid and keeping such preventive state for a prolonged period of time without changing a developability almost at all in a developer solution containing such a silver complexforming agent as thiosulfates, thiocyanates, alkanolamine, etc.
• R and R are selected from lower alkyl, aryl and aralkyl groups having 7 or less carbon atoms.
• the present compounds have already separately applied for a patent by the present inventors as a toner or a silver image and a developing accelerator for silver complex salt diffusion transfer, but the effectiveness of these compounds as an inhibitor for formation of colored sludge in the monobath developer solution was clarified by the successive studies, andin this respect the present invention has a great significance.
• Particularly effective among these compounds are 4-acetoamido-3 -heptyl-1,2 ,4-triazoline-5 -thione 4- propionamido-3-pentyl-l ,2,4-triazoline-5 -thione, 4- benzamido-3-phenyl-1,2 ,4-triazoline-5-thione, 4- benzamido-3-pentyl-l ,2 ,4-triazoline-5 -thione, 4-
• the amount of the present inhibitor for formation of colored sludge can be changed between 0.01 and 1.0 g per one liter of the solution, but a sufficient preventive effect can be usually attained by adding 0.1 to 0.5 g of the present inhibitor to one liter of the solution, without giving influences upon the developability and other photographic characteristics almost at all.
• inhibitors for formation of the colored sludge some inhibitors are only effective for a high speed negative emulsion, but the present compounds are effective for any of silver bromide, silver chloride, silver chloride-bromide, silver bromideiodide emulsions.
• the developer solution contains such a water-soluble silver complex-forming agent as sodium thiosulfate, it is possible to prevent the formation of colored sludge in quite the same principle even for the developing solution for a silver complex diffusion transfer process.
• the developing solution containing no developing ingredients which has been recently used in said process and is called activator, is an alkali solution containing a sulfite or further sodium thiosulfate, but the developing ingredients or the silver complex-forming agent is dissolved into the solution from the prints (negative and positive papers) during the developing treatment, and silver halide of the emulsion is dissolved therein.
• an alkali solution containing a sulfite or further sodium thiosulfate is an alkali solution containing a sulfite or further sodium thiosulfate, but the developing ingredients or the silver complex-forming agent is dissolved into the solution from the prints (negative and positive papers) during the developing treatment, and silver halide of the emulsion is dissolved therein.
• colored sludge due to the silver colloid is likewise formed.
• such formation can be prevented by adding the present compound thereto.
• EXAMPLE 2 Added to the recipe according to Example 1 was 0.3 g/l of 4-phenylacetamido-3-butyl-l ,2,4-triazoline-5- thione as an inhibitor for formation of the colored sludge due to the silver colloid.
• EXAMPLE 3 Added to the recipe according to Example 1 was 0.3 g/l of 4-acetamido-3-heptyl-l ,2,4'-triazoline-5-thione as an inhibitor for the formation of-colored sludge. On the other hand, another solution containing 0.3 g of the well-known DL-a-thioctic acid was prepared as a reference. After the treatment in the same manner as in Example 1, the residue solutions were left standing at room temperature. All the prints were formed good.
• the solution containing DL-a-thioctic acid started to form colored sludge after 7' hours and changed to black after 24 hours, and became equal to the solution containing no inhibitor as in Example 1.
• the solution containing 4-acetamido-3-heptyl-l ,2,4- triazoline-S-thione started to be changed to slightly yellowish after 24 hours, but the coloring did not proceed thereafter.
• the solution was not so changed after 5 days or 10 days almost at all as after one day. A very great effect upon the prevention of formation of colored sludge due to the silver colloid was observed.
• EXAMPLE 4 One liter of a monobath developing-fixing solution A solution according to the above recipe, which contained, in addition, 0.3 g/l of Z-mercapto-S-phenyl- 1,3,4-oxadiazole, the well-known inhibitor for formation of colored sludge, was prepared as a reference, whereas a solution according to the above recipe, which contained, in addition, 0.3 g/l of 4-benzamido-3- phenyl-l,2,4-triazoline-5-thione, was prepared. These solutions were used for the print treatment. The thus obtained prints were good for both solutions. No printout took place under direct beams of the sun.
• EXAMPLE 6 For a mono-bath (mono-bath developing-fixing solution) for a highly sensitive negative film, it was possible to use the solution prepared according to the recipe of Example 5, except that the amount of sodium thiosulfate therein was changed to about 60 g according to the compositionof a film emulsion, but the following recipe was suitable for. the specific purpose development:
• R and R are both phenyl.

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

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Citations (5)

• 1969
  • 1969-08-18 JP JP44064748A patent/JPS4826777B1/ja active Pending
• 1970
  • 1970-08-04 ZA ZA705394A patent/ZA705394B/xx unknown
  • 1970-08-17 DE DE2040801A patent/DE2040801B2/de active Granted
  • 1970-08-17 US US00064609A patent/US3769015A/en not_active Expired - Lifetime

Patent Citations (5)

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