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 related to chemical processing of photographic film. More specifically this invention is related to improved processing mixtures, and a diagnostic test therefore, which allows for accurate determination of replenishment and which provides a method for diagnosing improper replenishment.
• an image-wise exposed film must be processed to convert the latent image into a viewable negative of the image.
• the processing operation requires a development step, wherein the exposed silver halide crystals are reduced to elemental silver, and a fix or bleach step wherein the unexposed silver halide crystals are removed from the film. It is also advantageous to wash the film prior to drying and viewing.
• Ascorbic acid based developers are also used for reduction of exposed silver halide during development. Analogous depletion of active ingredients is observed with use.
• Hydroquinone developers are also susceptible to air oxidation.
• the chemical reaction associated with air oxidation is provided in Equation 2.
• Air oxidation of a hydroquinone developer does not effect the bromide level but the pH increases due to liberation of hydroxide ion as the sodium salt.
• Evaporation of water is also known to occur. Loss of solvent can alter the concentration of ingredients and the reactivity. Yet another detrimental phenomenon is the physical removal of developer solution by the film.
• Specific gravity is another analytical measurement which is often used during the initial makeup of the solutions. The inaccuracy and non-specificity of this method is well known in the art and diagnostic information is rarely obtained.
• film which utilize tabular grains are known to exhibit sensitometric properties which vary with bromide level in the developer. Films with more conventional grains are known to be less sensitive to bromide level but sensitometric differences correlate more strongly to processing temperature and other changes in developer. This places a burden on the health care professional since different films could exhibit different properties in the same processor. To adequately use the indirect method a control film would have to be established for all types of films employed.
• a particular deficiency of prior art tests is the lack of information on the activity of the replenisher chemicals.
• the bromide titration, or indirect film methods only test the activity of the development solutions in the processor at the time of the test.
• a single test provides no information about the replenishment conditions.
• To obtain information on replenishment a subsequent test must be done and the data correlated to analyze for trends and/or the replenisher must be checked independently.
• a film method is intrusive since the test film itself initiates the development reaction and some replenishment occurs to compensate therefor. Immediately after the control film is processed the conditions in the development solution will be different.
• An improperly prepared replenisher may take a considerable amount of time (several hours to several days) to displace a sufficient amount of developer to be observed by a film test.
• Nominal replenishment rates are sufficient to replace approximately half of the chemicals in the developer tank with replenisher chemicals in approximately 8-10 hours.
• the full effect of incorrect replenishment, either rate or composition may not be noticed until the developer has been replaced by at least one equal volume of replenisher.
• the lag time can span several days in some instances. Once an actual problem is detected the entire replenisher and developer must be replaced to correct the situation.
• the tardiness of the test is especially critical if recommended procedures are followed in entirety. Corrective action is suggested only after three consecutive test are observed to generate a trend in any direction away from the norm. Typical test frequency is daily for most situations but the actual time can vary substantially. Therefore, many inferior films could be produced prior to running a control which may lead to an incorrect diagnosis or a need to repeat the exposure to the patient.
• the practitioner is forced into one of the following two situations.
• the first is a correct film measurement indicating the current chemistry may be correct but replenishment conditions are unknown. In this situation the practitioner typically continues operating with no knowledge of potential problems.
• the second situation occurs when the film measurements are not correct. Based on the standard guidelines an initial check of obvious problems such as temperature, and the like, is suggested. If the problem is not resolved the processing and replenishment chemicals are usually discarded and replaced at a substantial financial and time burden to the medical professional.
• developer/replenisher solution can be monitored independent of the film thereby decreasing the effects of film, exposure and density measurements on the development conditions.
• Yet another object is a diagnostic test method which can determine if the replenisher or developer is properly mixed and which can provide diagnostic information for correcting an improperly prepared solution.
• a particular feature of the present invention is the ability to determine quantitative information rapidly and with minimal cost.
• a method for converting an image-wise exposed silver halide photographic film to a viewable image comprising: a development solution wherein said image-wise exposed silver halide is reduced to elemental silver with subsequent depletion of said development means; a fixing solution wherein unexposed silver halide is removed from said photographic film; a replenishing solution for said development means wherein said replenishing means comprises at least two titratably distinct components.
• the titratably distinct components are independently defined to have a Ksp between 10 ⁇ 6 and 10 ⁇ 20. It is also preferred that the Ksp of the titratably distinct ions differ by at least 10 ⁇ 2. Particularly preferred as titratably distinct components are bromide and chloride.
• Chemical developers are specifically formulated to efficiently reduce image-wise exposed silver halide to elemental silver.
• the developer typically comprises a reducing agent, optional antifoggants, optional pH buffers, optional hardeners and optional stabilizers.
• Each of at least two components of an inventive replenisher further comprise compounds which are analytically distinct one from the other when the components are mixed.
• analytically distinct preferably refers to compounds which are titratably distinct.
• titratably distinct refers specifically to compounds which can be quantitatively distinguished in a single potentiometric titration with silver nitrate.
• the titration should be done at a pH of which is sufficient to insure that silver oxide formation does not occur. This pH is preferably no higher than approximately 8.0.
• Preferred titratably distinct components are anions which form silver salts and which do not adversely interfere with the photographic development or fix process. It is particularly important that the silver salts formed are sufficient solubility that premature precipitation does not alter the results.
• Preferred is a salt with a solubility product (Ksp) of 10 ⁇ 6 to 10 ⁇ 20. Specifically preferred are combinations of anions which form silver salts with sufficient differences in solubility product to be quantitatively seperatable in a potentiometric titration.
• the solubility products of the silver salts, measured as Ksp, are preferably different by at lease 10 ⁇ 2 using current titration abilities under ambient conditions.
• the bromide is one titrant and the other titrants are chosen accordingly. Chloride has been found to be particularly preferred as a second titrant due to the low cost, photographic inert properties, solubility and the like.
• Preferred reducing agents are 4-hydroxymethyl-1-phenyl-3-pyrazolidone, 1-phenyl-3-pyrazolidone, or a derivative thereof such as 4-methyl or 4,4-dimethyl-1-phenyl-3-pyrazolidone; hydroquinone or a derivative thereof such as chlorohydroquinone or bromohydroquinone; ascorbic acid; sugar-type derivatives of ascorbic acid; stereoisomers and diastereoisomers of ascorbic acid and their sugar-type derivatives; or salts of ascorbic acid or their derivatives.
• Preferred reducing agents are hydroquinone, 4-hydroxymethyl-1-phenyl-3-pyrozolindone, 1-phenyl-3-pyrazolidone, ascorbic acid, d-erythroascorbic acid (i.e. erythorbic or isoascorbic acid), d-glucosascorbic acid, 6-deoxy-l-ascorbic acid, d-glucoascorbic acid, d-galactoascorbic acid, l-glucoascorbic acid and l-alloascorbic acid.
• d-erythroascorbic acid i.e. erythorbic or isoascorbic acid
• d-glucosascorbic acid 6-deoxy-l-ascorbic acid
• d-glucoascorbic acid d-galactoascorbic acid
• l-glucoascorbic acid l-alloascorbic acid.
• Exemplary salts of ascorbic acid include alkali metal salts, such as the sodium and potassium salts thereof (e.g. sodium or potassium ascorbate and sodium or potassium erythorbate).
• alkali metal salts such as the sodium and potassium salts thereof (e.g. sodium or potassium ascorbate and sodium or potassium erythorbate).
• the unsubstituted compounds of this class of compounds may be represented by the formula: wherein X is an oxygen atom or imino group, R is any group which does not render the ascorbic acid water-insoluble and is a non-interfering group.
• Non-interfering is defined as not causing steric hindrance, is not chemically reactive with other portions of the molecule, is not a coordination group for the molecule, and is not more electropositive than a saturated hydrocarbon residue.
• R is preferably an aryl group of 6-10 carbons or a group of the formula R1(CH2)(CH2) n-1 wherein n is a positive integer from 1 to 4 and R1 is either a hydrogen atom or hydroxyl group when n is 2 to 4 and is hydroxyl when n is 1.
• R1 is either a hydrogen atom or hydroxyl group when n is 2 to 4 and is hydroxyl when n is 1.
• ascorbic and erythorbic (iso-ascorbic) acid are preferred.
• the developer may contain a multitude of conventional ingredients which serve functions well known in the art. Included are additional development agents, antifoggant agents, pH buffers, sequestering agents, swelling control agents, development accelerators, and the like. Materials which may be included in the processing solution, such as swelling control agents (i.e. gelatin hardening agents), aerial oxidation restrainers, sequestering agents, surfactants, dyes, etc., well known in the art are exemplified in U.S. Pat. No. 3,545,971 and Photographic Processing Chemistry , L.F.A. Mason, 1966, page 149 et seq.
• reducing agents which may be used are organic agents such as catechols, aminophenols, phenylenediamines, tetrahydraquinolines, bis(pyridone)amines, cylcoalkenones, pyrimidines, reductones and coumarins.
• Inorganic development agents may also be mentioned to include metals having at least two distinct valence states and are capable of reducing ionic silver to metallic silver.
• metals include iron, titanium, vanadium and chromium and it is preferable to employ the metals with organic compounds such as polycarboxylic acids or aminopolycarboxylic acids.
• the organic antifoggant may be any organic antifoggant or film speed restrainer.
• organic antifoggants are commonly employed in X-ray developer baths and include compounds such as benzimidazole, benzotriazole, benzothiazole, indazole, tetrazole, imidazole, mercaptotetrazole 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 or two antifoggants such as 5-nitroindazole and benzotriazole. Sodium or potassium bromides are also suitable.
• Exemplary sequestering agents include but are not limited to aminopolycarboxylic acid compounds, ethylenediaminetetraacetic acid, and sodium salts thereof, diethylenetriaminepentaacetic acid, diaminopropanoltetraacetic acid, gluconic acid and its salts, hepto and borogluconates, citric acid and its salts.
• Exemplary swell control agents are dialdehydes or diketones particularly glyoxal, or homologous of glyoxal in which the two aldehyde groups are separated by a chain of 2 or 3 carbon atoms.
• Preferred is glutaraldehyde.
• Other compounds which may be mentioned include diacetyl, acetyl benzoyl and dichlorodiacetyl.
• a developer pH of approximately 9-12 be maintained. More preferred is a developer pH of approximately 9.7-10.6 and most preferred is a developer pH of 10.0 ⁇ 0.3.
• Any alkaline material may be used to provide the required pH, such as sodium or potassium hydroxide, sodium or potassium carbonate, etc.
• the buffer system may be any convenient system, e.g., the borate and carbonate buffers conventionally used in X-ray developer baths are quite suitable.
• the replenisher solution is ideally formulated such that addition to the developer restores the chemical composition of the developer to optimal composition under steady state conditions. It is typically preferred that the replenisher be substantially identical to the developer with the exception of the titratably distinct additives described herein.
• Ksp is standard in the art and refers specifically to the solubility product constant.
• the solubility constant can be defined as the product of the concentration of the ions of a substance in a saturated solution of the substance.
• the solubility product in water, at ambient temperatures, is a sufficiently close approximation to the solubility product in processing chemicals.
• the preferred developer composition and replenisher therefore comprises, per liter: 0.5 to 5.0 g. of 1-phenyl-3-pyrazolidone or a derivative thereof; 15 to 35 g. of hydroquinone, or a derivative thereof; 0 to 10 g. of bromide ion; 0.01 to 6.0 mmoles of an organic antifoggant; 1.0 to 30.0 g. of a titratably distinct ion and 0 to 30 g. of a different titratably distinct ion.
• the second titratably distinct ion is chloride.
• Another preferred developer composition and replenisher comprises, per liter, 15.0 to 75.0 g. of ascorbic acid; 0.5 to 5.0 g. of 3-pyrazolidone or a suitable derivative thereof; 2 to 20 grams of sulfite; 15 to 30 grams of carbonate; 0 to 10 g. of bromide ion; 0.01 to 6.0 mmoles of an organic antifoggant; 1.0 to 30.0 g. of a titratably distinct ion and 0 to 30.0 g. of a different titratably distinct ion.
• One embodiment, in accordance with the teachings herein, is the inclusion of one titratably distinct salt with the reducing agent and one titratably distinct salt with a second replenisher component.
• a range of bromide ion can be used successfully in this invention. It is preferred that one of the titratably distinct ions be KBr in an amount equal to 1 to 10 g/liter. NaBr may also be employed. Optimum amounts depend on replenishment rate and specific formula.
• a suitable replenishment rate will be about 50-70 mls per 240 square inches of film (40% exposed) for development to normal radiographic density, using the processing solution of the invention as properly prepared.
• Substantially all processors have some type of a standby replenishment mode. There are a lot of differences based on the manufacturer but the concept is usually similar.
• the standby mode typically 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 the 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.
• Solution 1 would contain salt A at a level sufficient to equal 4 g/l in the final mixture
• Solution 2 would contain salt B at a level sufficient to equal 4 g/l in the final mixture
• Solution 3 would contain salt A at a level sufficient to equal 1 g/l
• salt B at a level sufficient to equal 1 g/l in the final mixture.
• a properly prepared replenisher would be expected to contain 5 g/l of both salt A and salt B. If Solution 1 is added incorrectly then salt A will deviate from 5 g/l but salt B will be correct and so forth.
• R1 - representing a properly prepared replenisher solution Water 700 mls Solution A 250 mls Solution B 25 mls Solution C 25 mls
• R2 - representing a replenisher which is 10% overdiluted Solution
• R1 250 mls Water 25 mls
• R3 - representing a replenisher which is 15% overdiluted Solution
• R1 250 mls Water 37.5 mls
• R4 - representing replenisher with proper dilution but 10% shortage of Solution
• R5 - representing replenisher with proper dilution but 10% shortage of Solution
• Water 702.5 mls Solution A 250 mls Solution B 25 mls Solution C 22.5 mls R6 - representing a solution which is properly mixed but underdiluted by 10% Water 600 mls Solution A 250 mls Solution B 25 mls Solution C 25 mls Standard pH and specific
• the replenisher illustrated is substantially identical to that described in U.S. Pat. No. 4,741,991.
• This replenisher is intended to be used with a developer which has a steady state bromide level of approximately 6.0 to 7.0 g/l as the sodium salt.
• the development reaction would cause the bromide ion level to increase as film is developed in accordance with Equation 1.
• the combined teachings of U.S. Pat. No. 4,741,991 and U.S. Pat. No. 3,970,457 would suggest that the replenisher is added in an amount sufficient to return the bromide ion level to the predetermined level.
• a processor upset may be detected for each of R2 through R6 with no diagnostic information available based on the bromide ion titration alone.
• a titration of the developer replenished with R1 would have the predetermined level of bromide ion and chloride ion.
• a titration of the developer replenished with a set amount of R2 or R3 would have a bromide ion level which is lower than the predetermined level and a chloride ion level which is below the predetermined level.
• a developer replenished with a set amount of R4 would have a bromide ion level which is lower than the predetermined level and a chloride ion level which is at the predetermined level.
• a developer replenished with a set amount of R5 would have a bromide ion level which is at the predetermined level and a chloride ion level which is low.
• a developer replenished with a set amount of R6 would have a bromide and chloride level which is above the predetermined levels. In all cases the incorrect solution could be immediately corrected by changing replenishment amount or adding one component of replenisher.

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

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Citations (4)

• 1994
  • 1994-12-05 EP EP19940119119 patent/EP0660175B1/fr not_active Expired - Lifetime
  • 1994-12-05 DE DE1994623587 patent/DE69423587T2/de not_active Expired - Fee Related
  • 1994-12-21 JP JP31784394A patent/JPH07199418A/ja active Pending

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