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
  • G03C5/268—Processing baths not provided for elsewhere, e.g. pre-treatment, stop, intermediate or rinse baths
• • 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
  • Y10S430/167—X-ray

Definitions

• the invention relates to baths which inhibit swelling for treating exposed and developed photographic materials, so that processing can be accelerated by shortening the drying time.
• the melting point or melting temperature of the gelatin For use as protective colloid for photographic layers, the melting point or melting temperature of the gelatin must be increased. This can, in principle, be achieved by applying four different kinds of agents: water extracting agents (deswelling substances), agents which prevent swelling (hydrophobic agents), substances which precipitate gelatin and substances which tan gelatin. While the first three possibilities can be regarded as physical methods of reducing the swelling, the last method causes an irreversible chemical change of the gelatin structure. If water is extracted from the swelled gelatin layer by placing the layer in an alcoholic solution or concentrated salt solution, the reduced swelling is not maintained when the layers are again placed in pure water. The process is reversible.
• Heavy metal salt solutions which can form high molecular weight hydroxy salts, such as aluminum-, chromium-, trivalent iron-, cerium and uranyl salts act in a different way. The deswelling and hardening produced by them is irreversible since chemical complexes are formed.
• the gelatin layers are cross-linked so that the melting point is increased. After several months storage, the layers become horny and more brittle. This is termed after-hardening.
• slow-acting hardening agents are added, it is therefore necessary that the layers can be permeated by treatment baths even after a considerable storage time.
• photography it is customary to use as small a quantity of hardening agents as possible, especially in the case of highly sensitive emulsions where the reduction in permeability to development baths would immediately cause reduction in the sensitivity. The same applies to X-ray films. If the layers are only slightly hardened, the swelling remains high and the surface easily damaged during processing.
• hardening agents such as glutaric dialdehyde
• glutaric dialdehyde may be added to the developers. It is necessary in such an application to use hardening agents that are as active as possible, which agents must be stable in alkaline solution.
• a special hardening bath e.g., formalin solution containing alkali carbonate
• formalin solution containing alkali carbonate may also be interposed during processing either before or after development. The hardening which results is irreversible. Reversible deswelling is obtained with concentrated alkali metal salts. A slightly acid solution is usually employed.
• Examples of such compounds include oleyl sulfate, nonyl sulfate, alkyl sulfonic acids such as decylsulfonic acid, unsubstituted or substituted benzene sulfonic acids such as phenol sulfonic acids, unsubstituted or substituted naphthalene sulfonic acids such as naphthalene trisulfonic acid, naphthsultone -(1,8)- sulfonic acid-(3), and polymerized sulfonic acids such as polystyrene sulfonic acid, preferably having a molecular weight of up to about 3000.
• alkyl sulfonic acids such as decylsulfonic acid, unsubstituted or substituted benzene sulfonic acids such as phenol sulfonic acids, unsubstituted or substituted naphthalene sulfonic acids such as naphthalen
• the swelling is immediately reduced and reaches a minimum after 1 to 2 minutes. Since the solutions are highly diluted, the baths can also be used after washing. A considerable reduction in the drying times is achieved since owing to the reduced swelling, the quantity of water to be evaporated is smaller.
• the baths according to the invention are preferably used after development of the exposed silver halide emulsion layers, preferably at the end of the entire processing operation. No further treatment is required after the swell inhibiting bath according to the invention. Even washing is not necessary.
• the baths according tothe invention contain about 5 to 50 g., preferably 10 to 20 g./l. of the sulfates or sulfonic acids.
• the required pH is obtained by addition of organic or inorganic acids such as formic acid, acetic acid, hydrochloric acid.
• the baths are very stable and do not lose their activity for a long time.
• the moist photographic layers are left in the bath for l to 2 minutes. They acquire a leathery handle and no longer feel slimy.
• Excess solution can be removed from the treated material with a sponge.
• the materials dry about twice as quickly as the untreated samples.
• the developed materials can be briefly rinsed with water or washed since the deswelling, in contrast to that obtained with salts, is only eliminated after prolonged exposure to water. The effect immediately disappears if the layers are subsequently treated in an alkaline bath. Deswelling is strictly reversible and the baths according to the invention thus differ fundamentally from chemical hardening agents.
• Example 1 An exposed photographic film which is suitable particularly for X-ray photography and which contains a silver halide gelatin emulsion layer on both sides of a support of triacetyl cellulose is processed according to common practice in the following baths:
• the washed material is then placed directly into the baths described above for 1-4 minutes and in each case the swelling is determined after 1 minute.
• Example 2 A photographic element having a silver halide gelatin emulsion layer processed as in Example 1 is treated, after washing with water, with a bath of the following composition:
• Ageprun (wetting agent, trademark of Agfa- Gevaert AG) cc 5 Acetic acid cc 20 Naphthol-(D-sulfonic acid g 10 Water to make up to 1 l.
• the films are treated with a 4% sodium carbonate solution.
• Swelling is measured at intervals of 1 minute.
• Example 3 If the above-mentioned swelling-reducing substances are added to a bath at the end of the entire processing operation, the photographic layers dry considerably more quickly than after the usual washing with water.
• a hardening bath is generally employed.
• the hardening bath is usually combined with the fixing bath to form a so-called hardening-fixing bath.
• the common hardening-fixing baths have the disadvantage that they are not stable over prolonged periods, especially at elevated temperatures, since due to the reaction of the hardening agent, e.g., of the aluminum salt with sodium thiosulfate, the hardening-fixing bath becomes cloudy due to deposition of aluminum hydroxide and sulfur. More- 0 over, layers which are hardened with aluminum salt are brittle and make retouching more difiicult.
• a film which contained a silver bromide gelatin emulsion layer on a support of acetyl cellulose was used as photographic material.
• the relative air humidity was at the time of the measurements.
• the table shows that the effect of the final bath can be eliminated by sufficiently long washing with water.
• Example 4 In the same way as described in Example 3 a highly sensitive photographic film having a silver bromide gelatin emulsion layer containing about 5 moles percent of silver iodide was tested. After exposure, the film was developed with a developer of the following composition:
• a process for reducing the swelling of gelatin photographic layers including the step of contacting an exposed, developed and fixed photographic silver-halidegelatin layer with an 0.5 to 5% aqueous solution of an aliphatic or aromatic sulfonic acid or an aliphatic or aromatic sulfate, said acid or sulfate having more than 5 carbon atoms and said solution having a pH of between 1 and 6.
• a process as defined by claim 1 in which after the contacting the silver-halide-gelatin layer is washed for less than a minute and then dried.
• the improvement according to which the film is exposed, developed and fixed, and the swelling of the gelatin layer is then reduced by contacting the layer with 0 a 0.5 to 5% aqueous solution of an aliphatic or aromatic sulfonic acid or an aliphatic or aromatic sulfate, said s-ulfonic acid or sulfate having more than 5 carbon atoms, the solution having a pH of 2 to 3.

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

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Cited By (3)

Citations (5)

• 1966
  • 1966-04-15 US US542762A patent/US3467519A/en not_active Expired - Lifetime
  • 1966-04-28 NL NL6605716A patent/NL6605716A/xx unknown

Patent Citations (5)

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