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
  • G03C5/262—Processes using silver-salt-containing photosensitive materials or agents therefor using materials covered by groups G03C1/42 and G03C1/43

Definitions

• an activating bath It is known to add a developer substance to photographic films and to initiate development by treatment with an aqueous alkaline bath, the so-called activating bath.
• the main constituents of an activating bath are a compound for activating the developing process, usually a caustic alkali, and a preservative.
• caustic alkalis sodium carbonate, potassium carbonate, aluminates, phosphates or organic bases can also be used.
• Sodium sulfite is generally used as a preservative.
• Other additives can be present, such as stabilizers, development accelerators and wetting agents.
• Activation processes are advantageous because they are simple in their operation; results are obtained quickly; and the solutions can be made stable to oxidation. Activating baths are also efficient because only a limited quantity of developer substance in the photographic materials is available.
• a photographic activating bath for activating lightsensitive silver halide materials having developer substances incorporated in them comprising an aqueous solution of an alkaline substance, a preservative and one or more watermiscible alcohols of the formula where R is H, alkyl (C -C12), aryl, vinyl, Ch O(CH HO-[C(R R, is H or alkyl; and n is 1-4; in quantities of -60 percent by weight.
• Especially suitable water-miscible alcohols are the low-molecular-weight, monovalent, aliphatic alcohols, c.g., methanol, ethanol, propanol and butanol.
• the alcohols can be used alone or in mixtures.
• a useful mixture of alcohols is ethanol and tertiary butanol.
• the mode of operation of the alcohol-containing activating bath can probably be explained in that the diffusion of the hydrophilic developer substances out of the photographic films is retarded and swelling is re-- quizd; whereas, on the other hand, an improved solubility for compounds of the hydrophobic type is displayed so that hydrophobic developer substances can be used optimally for the activation process.
• Activating baths within the scope of the invention may contain some 560 grams/liter of alkali, 2-60 grams/liter of alkali sulfite and -600 milliliters/liter of a watermiscible alcohol.
• the pH of the activating solution should be located between 10 and 13.
• the activator solutions described can be applied to the exposed photographic material by known methods, e.g., by immersion, washing the material with a roller or by spraying. Subsequent to the activation process, the photographic material can be fixed and washed in the usual manner. If a longer storage stability is not necessary, a stabilizing bath can follow the activating bath. In the stabilizing bath, the unexposed silver halide is converted into a light-insensitive.
• the activator solutions described are suitable for activating all photographic silver halide materials which contain the developer substances in the light sensitive emulsion film or in an auxiliary layer such as an undercoated layer.
• Silver chloride, silver bromide and silver iodide emulsions are suitable, as well as emulsions containing mixtures of these halides.
• hydrophilic and hydrophobic types may be contained in the photographic films.
• suitable hydrophilic compounds are hydroquinone, catechol,
• hydroquinone sulfonate and chlorohydroquinone Suitable as hydrophobic compounds are butylhydroquinone, propyl gallate, and compounds the functional group or groups of which are inactivated by suitable protecting groups, for example, ester, ether or similar groups. Examples of such compounds are described in Offenlegungschrift No. 1,929,223 (German).
• the activating baths have a number of advantages. The most important advantage is that they exhibit increased activation when compared with the known baths, that is, they facilitate an optimum utilization of the developer substances contained in the film so that when these baths are used materials with superior density values are obtained.
• the activating baths are advantageous in that they reduce the swelling of th photographic films, which leads to obtaining materials with improved dimensional stability in processing. As a result of the reduced swelling, shorter drying times are necessary.
• the activating baths also exhibit very favorable effects on the diffusion of the developer substances so that uniformly developed silver images are obtained.
• the alcohol-containing activating bath increase the covering power of the developed silver more strongly than alkaline aqueous solutions, resulting in an additional saving of silver.
• Sample 1 hydroquinone Sample 2: catechol Sample 3: chlorohydroquinone Sample 4: propyl gallate
• the addition of these substances can take place as solids or as aqueous alcoholic solutions.
• the gelatin solution is then cast on a transparent polyester film base so that a solid coating of 1.5 grams of developer substance per square meter results.
• a silver chloride-silver bromide emulsion is applied, which contains 70 mol-percent of chloride and 30 molpercent of bromide. The silver coating amounts to 9 grams/ square meter.
• a protective gelatin film is applied and hardened in the usual manner. After drying, the material is contact exposed with an incandescent light (30 watt) at a distance of 1.5 meters in aa vacuum printing frame. For comparison, a sample strip of the lightsensitive material is treated with a conventional aqueous activating bath A and another strip is treated with an alcohol-containing activating bath B.
• Aqueous activator bath A consists of:
• the treatment of the sample strips takes place under the same conditions, l0 seconds at 20C.
• EXAMPLE 2 A light-sensitive material produced according to Example l is used except that as developer substances, the following compounds are added to the basecoat:
• Sample I hydroquinone sulfonate grams
• Sample 2 15 grams of the monoester of hydroquinone with a-triethylaminoacetic acid chloride (compound I of Offenlegungschrift No. 1,929,223).
• EXAMPLE 3 Four samples of the material produced and exposed according to Example I, in each case, are treated with the conventional bath A given in Example I and, for comparison therewith, with baths in which 200 cm" of the water in bath A is replaced by 200 cm of various alcohols or mixtures of alcohols.
• Bath B contains 200 cm of allyl alcohol
• Bath C contains 200 cm of ethanol
• Bath D contains 200 cm of tert.-butanol
• Bath E contains 200 cm' of ethylene glycol cm of ethanol and 20 cm of tert.-butanol
• Bath F contains 180 cm" of ethanol and 20 cm of dodecyl alcohol
• Bath G contains Treatment is carried out for l0 seconds at 20C. and the results are compiled in Tables 3 and 4.
• the activating bath coni 1.; 00:; I1 0:03 sisting essentially of an aqueous solution of an alkaline substance selected from the group consisting of caustic o 3.0 0.011
• Bath B contains 400 cm of ethanol
• Bath C contains 400 cm of isopropanol
• Bath D contains 400cm of tert.-butanol I00 cm of benzyl alcohol 100 cm" of methanol 200 cm of acetone
• Bath E contains Bath F contains 400 cm of methylglycol 360 cm" of ethanol 40 cm of tert.-butanol Bath
• G contains Treatment is carried out for 30 seconds at 20C. and the results are given in Table 5.
• r is H, alkul (C -C 2), aryl, vinyl, Ch O-(CH HO[C(R R is H or alkyl; andn is 1-4; in quantities of lO-60 percent by weight.

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

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Citations (7)

• 0
  • BE BE794397D patent/BE794397A/fr unknown
• 1973
  • 1973-01-12 US US323316A patent/US3864129A/en not_active Expired - Lifetime
  • 1973-01-23 GB GB346573A patent/GB1371591A/en not_active Expired

Patent Citations (7)

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