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
  • G03C5/29—Development processes or agents therefor
  • G03C5/30—Developers
• • 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
  • G03C5/29—Development processes or agents therefor
  • G03C5/31—Regeneration; Replenishers

Definitions

• This invention is in the field of photographic silver halide developer solutions and replenishers therefor, and is specifically directed to developer-replenisher solutions useful in low through-put machine processing (developing) of photographic film.
• processing solutions become exhausted by the passage of the exposed silver halide film and replenishment must be made to account for ingredient loss.
• the processing fluids, especially the developer solution are degraded aerobically by contact with air and anerobically when simply left for long periods of inaction.
• the other ingredients are set at concentrations which allow for the expected losses, the hydroquinone being offset by the antifoggants, without substantially affecting the sensitometry. In this situation a replenishment rate can be conveniently calculated based on the approximate area of film fed into the processor.
• the present invention provides a replenisher formulation which is aimed at compensating for developer changes caused by nonuse,and not by the development reaction.
• the replenisher is characterized by a pH lower than that of the developer, and it contains the maximum amount of bromide consistent with acceptable sensitometry.
• pH will remain constant or slightly decrease, the bromide will remain essentially constant, and the other changes will compensate as in state of the art formulations.
• the developer composition can maintain a useful lifetime equivalent to the high throughput processors.
• a further object is to provide a developer/replenisher system particularly useful for machine processing of X-ray film when low throughput of film is practised.
• an aqueous processing solution useful as a photographic developer bath for automatic processing of silver halide photographic film, particularly X-ray film, and as a replenisher therefor, consisting essentially of, per liter: with the proviso that the replenisher solution will not only contain bromide ion but also will have a lower pH than that of the developer solution.
• a further embodiment of the invention is a process for the automatic processing of exposed photographic silver halide X-ray film wherein the imagewise exposed X-ray film is developed in a photographic developer bath comprising a photographic developer, bromide ion, an alkaline material and buffer system to maintain the pH of the developer bath at a desired value, an organic antifoggant and film speed restrainer, and water; the developed X-ray film is fixed, washed and dried; and the developer bath is replenished by a replenisher solution to maintain constant the photographic properties of the developer bath during processing of a large quantity of exposed X-ray film, characterized in that the processing solution described above serves as both the developer bath and the replenisher solution; with the proviso that the latter have a pH lower than that of the developer.
• the processing solution of this invention can be used for both the developer and the replenisher therefor.
• the replenisher solution has a lower pH than that of the developer
• a small amount of base alkaline material
• the replenisher is added to the developer bath as needed, based on time and/or the amount of film processed, thus compensating for both forms of developer exhaustion. It is surprising that this particular formulation can be used so successfully for low throughput in automatic processors since the differences between it and the prior art are so slight.
• the difference in performance between the formulation of this invention and the prior art is very large.
• a combination of 1-phenyl-3-pyrazolidone (sold under the Ilford trademark Phenidone) or a derivative thereof such as 4-methyl or 4,4-dimethyl phenidone, and hydroquinone or a derivative thereof such as chlorohydroquinone or bromohydroquinone is used.
• This combination is particularly suited for automatic processing of X-ray films.
• These ordinarily comprise a gelatino-AgBr, AgBrI, or AgClBrI emulsion on a film support such as polyethylene terephthalate.
• the buffer system may be any convenient system, e.g., the borate and carbonate buffers conventionally used in X-ray developer baths are both suitable.
• the organic antifoggant may be any organic antifoggant and film speed restrainer.
• organic antifoggants are commonly employed in X-ray developer baths and include compounds of the benzimidazole, benzotriazole, benzothiazole, indazole, tetrazole, and thiazole group, as well as anthraquinone sulfonic acid salts.
• Two or more organic antifoggants may be used. It is preferred to use a mixture of two antifoggants such as 5-nitroindazole and benzotriazole.
• a range of bromide ion can be used successfully in this invention and provides excellent stability. 1 to 10 g/liter of KBr, for example, will provide sufficient bromide ion. NaBr may also be employed. Optimum amounts depend on replenishment rate and specific formula.
• processing solution may include gelatin hardening agents, aerial oxidation r-estrainers, sequestering agents, surfactants, dyes, etc., as well known in the art. See, e.g., U.S. Patent 3,545,971 and "Photographic Processing Chemistry", supra, page 149 et seq.
• Replenishment will be carried out at a rate per unit area of exposed film to provide processing of a large quantity of exposed film without change in sensitometric properties of the film, and will be determined empirically, as is known.
• a suitable replenishment rate will be about 55 ml per 240 square inches of exposed film for development to normal radiographic density, using the processing solution of the invention.
• Some processors have a standby replenishment mode. This works as follows: if no film is passed in a given time, the processor goes into a standby mode which deactivates the drive train and dryer and reduces water supply. After a given time, it comes back on for several minutes and then shuts off again. After a specified number of cycles, it replenishes a predetermined amount. This replenishment is not effective with current developer/replenisher formulations but very effective with this invention since more of the correct replenisher is used.
• the silver halide film is fixed, preferably in an acid fixer, and washed and dried in the usual manner. If a processing machine is used, these steps will be determined by the machine.
• Example 1 is the best mode contemplated by the inventor of carrying out the invention.
• Processing time was about 2-1/2 minutes at 92°F.
• the processor was equipped with a conventional ammonium thiosulfate fixer solution.
• D eveloper/replenisher I of Example 1 was operated for more than thirteen weeks at low throughput at St. Joseph's Hospital in Phoenix, Arizona in a Cronex QC-1 processor under essentially the same conditions as Example 1. The same formula was also run over four weeks at high throughput, thus demonstrating that developer/replenishers of this invention exhibit excellent stability over long periods of time in both high and low throughput.
• a developer solution was made up as follows: Five gallons (approx. 19 liters) of this developer were charged to the processor described in Example 1. About 60 grams of acetic acid were added to the remaining 19 liters to give a pH of 10.0 + 0.05 and this was used as the replenisher. The processor was also charged with standard ammonium thiosulfate fixer and set at 92°F. Two samples of exposed X-ray film (high speed CRONEX®4, E. I. du Pont de Nemours and Company), 14 x 17 inch size, were processed (developed) and the sensitometry of the system checked with control strips as described in Example 1. The processor was then allowed to stand by for the remainder of the day.
• Example 2 The formula of Example 2 (pH about 10.2) was used in this example, as both developer and replenisher, in the processor of Example 1. Under low throughput conditions (7 to 10 sheets of X-ray film/day) it served for more than five weeks. At the end of this period of time, control strips processed in this machine showed that the activity of the developer was well within limits and produced excellent results. A conventional developer of the prior art deteriorates badly in less than two weeks under these conditions and requires shut-down and cleaning of the automatic processor followed by re-charging with fresh solution.

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

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• 1982
  • 1982-06-30 DE DE8282303437T patent/DE3268792D1/de not_active Expired
  • 1982-06-30 EP EP82303437A patent/EP0071344B1/fr not_active Expired
  • 1982-07-22 MX MX193692A patent/MX161751A/es unknown
  • 1982-07-22 JP JP57126859A patent/JPS5837644A/ja active Granted
  • 1982-07-22 NZ NZ201355A patent/NZ201355A/xx unknown
  • 1982-07-22 CA CA000407806A patent/CA1181624A/fr not_active Expired
  • 1982-07-22 ZA ZA825244A patent/ZA825244B/xx unknown
  • 1982-07-22 AU AU86296/82A patent/AU554484B2/en not_active Ceased

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