JPS6152460B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a gasket for an electrodialysis layer used in a method for regenerating photographic processing solution waste using ion exchange membrane electrodialysis. When the developing agent in the photographic developer reduces exposed silver bromide, silver iodide, and silver chloride in the emulsion layer of a light-sensitive material to form a silver image in the development process, the developing agent in the emulsion layer is Produces main ingredient oxidation products, bromide ions, iodide ions, and chloride ions as by-products. Bromine ions and/or iodide ions, which are by-produced at this time, accumulate in the developer waste and affect photographic properties, so in order to recycle the developer waste, it is necessary to remove these halide ions. is necessary. In the development process of color photographic light-sensitive materials, the silver image and late-exposed silver halide produced by the above development are desilvered by a bleach and fixing solution, or a bleach-fixing solution, and finally only a color image is produced. A process that leaves behind is usually required. However, when color photographic light-sensitive materials are bleach-fixed, silver thiosulfate and halide ions accumulate in the bleach-fix solution. Since the silver oxidizing ability decreases when it changes to iron complex ions, it is absolutely necessary to oxidize the ferrous complex ions to ferric complex ions in order to regenerate and reuse this bleach-fix solution. As a method for removing halide ions from the waste solution of the photographic developer, and as a method for removing silver thiosulfate and halide ions from the photographic bleach-fix solution,
The cathode and anode are alternately partitioned by cation exchange membranes and anion exchange membranes, and from the cathode side to the anode side there are a cathode chamber and multiple desalination chambers (cation exchange membrane on the cathode side, anion exchange membrane on the anode side). A desalination chamber of an ion exchange membrane electrodialysis tank consisting of a chamber separated by an exchange membrane), multiple concentration chambers (chamber divided by an anion exchange membrane on the cathode side and a cation exchange membrane on the anode side), and an anode chamber. A known method is to perform electrodialysis (ion exchange membrane electrodialysis method) by pouring waste developer solution into a concentration chamber, pouring a sodium sulfate solution or sodium carbonate into a concentration chamber, and passing a direct current to both the anode and negative poles (ion exchange membrane electrodialysis method). Mizusawa, A.Sasai and N.Mii;Bulletin of
the Society of Scientific Photography of
Japan.No. 18.38-44.1968 reports experimental data regarding the removal of bromide ions from developer waste using an ion exchange membrane with a current density of 0.50 A/dm ² to 2.0 A/dm ² . Furthermore, methods for regenerating the developer using ion-exchange membrane electrodialysis are disclosed in Japanese Patent Publication No. 52-34939,
-84636, 51-85722, 51-97432, 52-119934,
53-149331, 53-46732, 54-9626, 54-19741,
53-7234, 52-146236, 52-143018, 54-58028
A method for regenerating the bleach-fix solution is described in Japanese Patent Application Laid-open No. 53-60371. Electrodialysis cells commonly used a mixture of styrene-butadiene copolymer and natural rubber or neoprene. The present inventor has discovered that the material of the rubber gasket used in the ion exchange membrane electrodialysis cell has a very significant effect on the characteristics of the photographic processing solution.
That is, the rubber gasket used in the ion exchange membrane electrodialysis tank must have the following properties. 1 Appropriate strength Mechanical strength, smoothness, if the ion exchange membranes are layered and the rubber gasket is too hard, the adhesion will be poor. As a result, fluid leaks between the desalting solution (development waste solution) and the concentrated solution, which is not only inconvenient in terms of dialysis efficiency, but also extremely undesirable as the solution leaks from the surface of the dialysis tank. A situation happens. Furthermore, even if this rubber is too soft, it is difficult to assemble a dialysis tank while maintaining a certain distance between the rubber gasket and the ion exchange membrane. Furthermore, since such a precise tank is required, if the rubber gasket is too soft, processing accuracy will be reduced, and the process of attaching the ion exchange membrane and assembling the tank itself will be extremely difficult. Therefore, appropriate hardness and mechanical strength are required. 2 Chemical Resistance Developer waste is a particularly concentrated alkaline solution (usually PH > 10) and may also contain benzyl alcohol and diethylene glycol. In addition, the bleach-fix waste solution has weak oxidizing properties, and when considering the developer components brought into the bleach-fix solution, it also contains various PH buffer components. Therefore, the rubber gasket used in the dialysis tank for photographic processing solution waste is
It must have sufficient resistance to such chemicals. In addition to these properties, a rubber gasket for an ion-exchange membrane electrodialyzer for photographic processing solution waste must also satisfy photographic properties that exceed the common knowledge of general electrodialysis technology. 3 Photographic Properties Silver halide photographic materials are inherently very sensitive to trace amounts of chemical substances and their properties may change. For example, the photographic sensitivity may be desensitized or sensitized, or fog may occur, making it impossible to obtain uniform photographic properties under certain processing conditions.Furthermore, color photographic materials may not be as clear in the end. Although it is necessary to obtain only a color image, a phenomenon of poor desilvering may occur, reducing the sharpness of the color image. These problems must be completely avoided even when regenerating photographic processing solutions. Neoprene rubber, which is generally used in electrodialysis tanks in fields other than photography, satisfies characteristics 1 and 2 above, but in the special field of photographic processing liquids, it has not been possible to obtain one that satisfies photographic characteristics 3. . In addition, although gaskets made of ethylene vinyl acetate copolymer satisfy conditions 2 and 3, they have too high hardness as described in 1, making them difficult to compatibility with the ion exchange membrane and the gasket, resulting in frequent liquid leaks, making them unusable. do not have. In addition, various common rubber materials were investigated, but none satisfied the photographic properties described in 3. The object of the present invention is to provide a rubber gasket material that can be used in an ion exchange membrane electrodialysis tank for regenerating photographic processing waste liquid and has the above-mentioned necessary characteristics.
The goal is to provide the perfect product. In particular, it is an object of the present invention to provide a material for a rubber gasket that does not deteriorate the photographic properties of the recycled processing solution and has appropriate physical strength. The object of the present invention has been achieved by using an ethylene-propylene rubbery copolymer as a gasket material for an ion-exchange membrane electrodialysis tank when photographic processing solution waste is regenerated for ion-exchange membrane electrodialysis. In the present invention, the photographic processing solution waste mainly refers to waste solutions of photographic developers and color photographic bleach-fix solutions. In the present invention, the gasket of the ion exchange membrane electrodialysis tank is composed of an ethylene-propylene rubbery copolymer, but the ethylene-propylene rubbery copolymer is not particularly limited, and known rubbery copolymers may be used. Can be used. For example, the so-called EPR obtained by copolymerizing ethylene monomer and propylene monomer
EPT or EPDM, which is obtained by copolymerizing ethylene monomer, propylene monomer and diene monomer, is preferably used. Further, the ratio of ethylene units to propylene units in the ethylene-propylene rubbery copolymer is not limited and can be any value as long as the copolymer exhibits rubber elasticity. In general, those containing 35 to 90% ethylene units, preferably 50 to 75%, more preferably 60 to 70%, can be most widely used. In addition, in the case of the three-element copolymer obtained by copolymerizing ethylene monomer, propylene monomer, and diene monomer called EPT or EPDM, the diene monomer as the third component is not particularly limited, but generally several % or less is preferably used. As the diene monomer, known ones can be used, and generally diene monomers having a non-conjugated double bond such as butadiene, isoprene, or 1,4
-Butadiene, dicyclopentadiene, 1,4-
Diene monomers having a conjugated double bond such as cyclohexadiene, methylene norbolene, ethylidene norbornene, etc. are preferably used. The above EPR, EPT or
When a rubbery copolymer called EPDM is used as a gasket material for an ion-exchange membrane electrodialysis tank, it will be explained later in comparison to other synthetic resins such as vinyl acetate-ethylene copolymer, neoprene rubber, silicone rubber, etc. As is clear from the examples, the regenerated solution obtained by regenerating the waste solution can be used as a developing solution or a bleach-fixing solution with almost no adverse effects. On the other hand, when other synthetic resins are used as the gasket material, as is clear from the comparative examples described later, when the recycled liquid obtained by recycling the waste liquid is used as a developer or a fixer for bleaching, the potash becomes large. Defects such as incomplete desilvering or easy liquid leakage occur, making it impossible to obtain a satisfactory regenerating liquid. It is surprising that such development is caused by differences in the gasket materials of ion-exchange membrane electrodialyzers, but the mechanism of action is still unclear. Even in the case of ethylene-propylene rubber-like copolymers, those that do not use a sulfur-containing compound as a vulcanizing agent or vulcanization accelerator are preferred. Further, it is preferable that the addition of an amine compound as an anti-aging agent and fatty acids and their salts as additives be minimized or not used at all. This is because the additives mentioned above are used during ion exchange membrane electrodialysis treatment.
It is thought that a small amount of it dissolves in the processing liquid or chemically reacts with the components contained in the processing liquid, thereby deteriorating the performance of the processing liquid. In particular, developer waste liquid contains organic solvents such as benzyl alcohol and diethylene glycol, and is highly alkaline, so it is thought that the conditions are perfect for these rubber additives to be more easily extracted into the processing liquid. For this reason, the material of the rubber gasket in the dialysis tank for photographic processing solutions must be carefully examined, and everyone must admit that its precision exceeds common sense even in ion exchange membrane electrodialysis technology. Materials for the cathode of the electrodialysis layer and electrolytic layer include iron, nickel, lead, zinc, stainless steel, etc., and materials for the anode include platinum, platinum-plated titanium, graphite, etc. The anion exchange membrane is preferably a strongly basic type, and the cation exchange membrane is preferably a strongly acidic type. The electrolyte solution poured into the cathode chamber, concentration chamber, anode chamber of the electrodialysis layer and the anode chamber of the electrolyte layer includes an alkaline solution such as sodium hydroxide solution, sodium carbonate solution, potassium carbonate solution or potassium hydroxide solution, sodium sulfate. Examples include solutions of salts such as solutions, and solutions of acids such as sulfuric acid. It is sufficient that the concentration of these electrolyte solutions is 0.001N or more, and more preferably 0.01 to 2N. More preferably, these solutions contain a chelating agent, such as an aminopolycarboxylic acid or an aminopolyphosphonic acid. In particular, with respect to the concentrated solution, the developer waste solution may be composed of a corresponding developer waste solution for regenerating a developer waste solution, and the bleach-fix solution or thiosulfate and sodium sulfite may be used for regenerating a bleach-fix solution waste solution. In addition, the current density applied to the ion exchange membrane electrodialysis of these developer waste solutions varies depending on the characteristics of the ion exchange membrane and the characteristics of the developer waste solution, but is generally 0.1 A/dm ² to 10 A/dm ² , more preferably. is 0.2A/ ^dm2 to 5A/ ^dm2 . The ion exchange membrane electrodialysis method of the present invention consists of a cathode chamber in which the cathode and anode are alternately partitioned by cation exchange membranes and anion exchange membranes, and a plurality of demineralization chambers (the cathode side is the cation exchange membrane anode). An ion exchange membrane electrodialysis layer consisting of a chamber (chamber partitioned on the side by an anion exchange membrane), multiple concentration chambers (chamber partitioned by an anion exchange membrane on the cathode side and a cation exchange membrane on the anode side), and an anode chamber. Pour the waste developer solution or waste bleach-fix solution into the desalination chamber, and pour an electrolyte solution such as sodium sulfate solution or sodium carbonate into the cathode, concentration chamber, and anode chamber, and pass a direct current between the negative and anode electrodes to remove the waste solution from the developer solution. A method for removing bromide ions and/or iodide ions or silver, complex ions, and halide ions in a bleach-fix solution.Also, an electrolytic cell consisting of a cathode chamber and an anode chamber in which the cathode and anode are separated by an anion exchange membrane. This ion-exchange membrane electrodialysis method also includes a method in which developer waste is poured into the cathode chamber of the anode chamber, an electrolyte solution such as a sodium sulfate solution is poured into the anode chamber, and a direct current is passed between the negative and anode electrodes to remove bromide ions from the developer waste. . To regenerate a photographic developing solution or a bleach-fixing solution by the ion-exchange membrane electrodialysis method of the present invention, the waste solution is immediately or simultaneously supplied to the desalination chamber of the dialysis layer,
53-46, 732, 52-146, 236, 54-9, 626, 54-
Polymers, resins, and various ion exchange resins (e.g., Diaion SA-10A, SA-20A, PA-
316, 418, WA-11, WA-20, CR-10, PK-
220, PK-208, Diuolite S-37, and Amberlite IR-410), the method of the present invention also includes contact treatment of the waste liquid with an adsorbent such as Amberlite IR-410. To regenerate the photographic processing solution according to the method of the present invention, if there is essentially no change in the fact that the waste solution is supplied to the demineralization chamber of the dialysis layer and subjected to electrodialysis, the waste solution is supplied to the demineralization chamber. It may be supplied to the cathode chamber immediately before, immediately after, or at the same time (for example, in Japanese Patent Application Laid-Open No.
85722), and the cathode chamber also includes a method of supplying the electrolyte solution from the same tank,
It also includes a method in which the electrolyte solution is supplied to the concentration chamber and the cathode chamber or the concentration chamber and the cathode chamber from the same tank. In the method for regenerating photographic processing solution waste using the ion-exchange membrane electrodialysis method of the present invention, the processing solution waste discharged from the photographic processor is temporarily stored, and then the present ion-exchange membrane electrodialysis method (and in some cases It also includes the so-called batch method, in which halide ions, salts, silver, etc. are removed and recovered using a method (combined with an electrolytic method), and then a deficient treatment agent component is added and used again as a replenisher. By detecting, for example, bromide ions in the photographic processing solution as described in Japanese Patent Application Laid-Open No. 54-37731, bromide ions can be maintained at a constant bromide concentration while controlling the amount of current applied to the ion exchange membrane electrodialysis tank. This method also includes a so-called continuous regeneration method in which only the deficient processing agent components are added to the waste processing solution discharged from the photographic processor after dialysis removal of ions and the waste is used again as a replenisher. Further, in order to perform electrodialysis while maintaining high current efficiency, the concentrated solution may be diluted with water as appropriate. In particular, when using the continuous regeneration method described above, the concentrated solution may be diluted with water so as to keep the halide ion concentration, for example, bromide ion concentration, in the concentrated solution constant in the range of 2 to 20 g/concentration in terms of potassium bromide. It is more preferable to keep the bromide ions in the developer constant to reduce fluctuations in photographic properties and to maintain high current efficiency for removing bromide ions from the developer. To replenish water for diluting this concentrated solution, for example, by operating the pump in synchronization with the replenishment pump that replenishes the replenisher tank of the automatic developer, the sensitive material to be developed can be replenished. The bromide ion concentration in the concentrate is kept almost constant, the bromide ion concentration in the developer is more stable, and efficient dialysis can be maintained. More preferred. In the case of the batch regeneration method, the bromide ion concentration in the concentrate increases with the dialysis time, so the bromide ion concentration in the concentrate increases by 2g to 20g/during the dialysis.
It is preferable to dilute the concentrated liquid by replenishing a certain amount of water with a pump so that (in terms of KBr). The developer solution to be regenerated using the present invention can contain known developing agents. As developing agents, dihydroxybenzenes (e.g. hydroquinone), 3-pyrazolidones (e.g. 1-
phenyl-3-pyrazolidone), aminophenols (e.g. N-methyl-P-aminophenol), 1-phenyl-3-pyrazolines, ascorbic acid, and 1,2, as described in U.S. Pat. No. 4,067,872. Heterocyclic compounds in which a 3,4-tetrahydroquinoline ring and an indolene ring are condensed can be used alone or in combination. The developing solution generally contains other well-known preservatives, alkaline agents, PH buffers, antifoggants, etc., and, if necessary, solubilizing agents, color toners, development accelerators, surfactants, antifoaming agents, etc. It may also contain water softeners, hardeners, viscosity-imparting agents, and the like. Color developers that can be regenerated using the present invention generally consist of alkaline aqueous solutions containing color developing agents. The color developing agent is a known primary aromatic amine developer, such as phenylene diamines (for example, 4-amino-N,N-diethylaniline, 3
-Methyl-4-amino-N,N-diethylaniline, 4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N
-Ethyl-N-β-hydroxyethylaniline,
3-methyl-4-amino-N-ethyl-N-β-
methanesulfamide ethylaniline, 4-amino-3-methyl-N-ethyl-N-β-methoxyethylaniline, etc.) can be used. OthersPhotographic Processing by LFAMason
Chemistry (Focal Press, 1966), 226~
229, those described in U.S. Pat. No. 2,193,015, U.S. Pat. Color developers also contain pH buffering agents such as alkali metal sulfites, carbonates, borates and phosphates, development inhibitors or antifoggants such as bromines, iodides and organic antifoggants. be able to. If necessary, water softeners, preservatives such as hydroxylamine, organic solvents such as benzyl alcohol and diethylene glycol, development accelerators such as polyethylene glycol, quaternary ammonium salts, and amines, dye-forming couplers, competitive couplers, Fogging agents such as sodium borohydride, auxiliary developers such as 1-phenyl-3-pyrazolidone, viscosity-imparting agents, US Pat. No. 4,083,723
It may also contain a polycarboxylic acid chelating agent described in No. 1, an antioxidant described in OLS No. 2622950, and the like. The bleach-fix solution that can be reproduced using the present invention contains iron (), cobalt (), chromium (),
It can include compounds of polyvalent metals such as copper (), peracids, quinones, nitroso compounds, and the like. For example, ferricyanide, dichromate,
Organic complex salts of iron () or cobalt (), such as aminopolycarboxylic acids such as ethylenediaminetetraacetic acid, nitrilotriacetic acid, 1,3-diamino-propanoltetraacetic acid, or complex salts of organic acids such as citric acid, tartaric acid, malic acid; sulfate,
Permanganate; nitrosophenol, etc. can be used. Of these, potassium ferricyanide, sodium ferric ethylenediaminetetraacetate, and ammonium ferric ethylenediaminetetraacetate are particularly useful. Bleach-fix solutions include U.S. Patent No. 3,042,520, U.S. Patent No. 3,241,966,
In addition to the bleach accelerators described in Japanese Patent Publication No. 8506-8506 and Japanese Patent Publication No. 45-8836, and the thiol compounds described in Japanese Patent Application Laid-open No. 65732-1983, various additives can also be added. Further, the silver halide light-sensitive material and photographic processing solution according to the method of the present invention, and the silver halide photographic light-sensitive material processed using the same, are also described in "Photographic Processing Chemistry" by LFA Mason, Focal
Press (1974), “The Theory” by T.H.
of the Photographic Process”Macmillan
Publishers (1977), Research Disclosure No.
17643 (December 1978). Next, the method of the present invention will be explained with reference to Examples, but the content of the present invention is not limited thereto. Example Fuji color paper that has been exposed to print is subjected to the steps shown in Table 3 using a color paper automatic developing machine consisting of a color developing solution having the composition shown in Table 1, a bleach-fixing solution having the composition shown in Table 2, and washing water. Continuous development processing was performed. Table 1 Benzyl alcohol 15ml Diethylene glycol 8ml Ethylenediaminetetraacetic acid/2tonalium salt 5g Sodium sulfite 2g Anhydrous potassium carbonate 30g Hydroxylamine sulfate 3g Potassium bromide 0.6g 4-Amino-N-ethyl-N-(β-methanesulfonamide) ethyl)-m-toluidine 3/
Disulfate/monohydrate 5g Add water adjusted to pH 10.20 with caustic soda
1 Table 2 Ethylenediaminetetraacetic acid 2g Ethylenediaminetetraacetic acid ferric salt 40g Sodium sulfite 5g Ammonium thiosulfate 70g Add water 1 Table 3 Development process Color development 3 minutes 30 seconds 33℃ Bleach fixing 1 minute 30 seconds 33℃ Wash with water 2 minutes and 30 seconds 25-30°C This color developer tank was connected to a desalting chamber of an ion exchange membrane electrodialysis tank as shown below, and the color developer was circulated. By adjusting the amount of current applied to this dialysis tank, color paper was developed while keeping the KBr concentration of the color developer constant. In the ion exchange membrane electrodialysis tank used here, the stainless steel cathode and platinum-plated titanium anode are alternately partitioned by 20 strong acid type cation exchange membranes and 20 strong base type anion exchange membranes. Rubber gaskets made of various materials shown in Table 4 were sandwiched between the ion exchange membranes of the ion exchange membranes to form one cathode chamber and 20 concentration chambers (the cathode side was partitioned by an anion exchange membrane and the anode side was partitioned by a cation exchange membrane. It consists of 19 demineralization chambers (chambers separated by a cation exchange membrane on the cathode side and an anion exchange membrane on the anode side), and one anode chamber.
A developing solution is supplied as described above to the desalination chamber of this dialysis tank, a 30 g/aqueous sodium sulfate solution is supplied to the concentration chamber, and 30 g/aqueous solution is supplied to the cathode chamber and anode chamber.
An aqueous solution of sodium sulfate was supplied in a separate system from the concentration chamber, and a direct current was passed between the cathode and anode, and color paper was developed while performing electrodialysis. After performing these continuous development treatments for a certain period of time,
Table 5 shows the photographic performance obtained by developing strips exposed to three-color separation through an optical wedge in which the exposure amount was changed stepwise.

【table】

【table】

[Table] Desilvering is indicated by the blue light density (subtracting the blue light density at which desilvering is complete) in the constant exposure area of the red-sensitive layer, so the higher the value, the more silver remains that has not been desilvered. This indicates that the color purity deteriorates. The sensitivity is expressed as a relative sensitivity to the sensitivity of color paper processed using the new solution prepared according to the formulations in Tables 1 and 2 at a concentration of 1.0, so - indicates desensitization + indicates sensitization. Rubber hardness is JIS-K-
This is the value measured with 6301-5. As is clear from the above results, the rubber gaskets that can be used for recycling (halide ion removal) of photographic processing solution waste are very limited, and only ethylene propylene copolymer can satisfy both photographic properties and physical properties. . In other words, although the styrene-butadiene copolymer and neoprene rubber of Test 1, which are commonly used for dialysis tanks, have satisfactory physical properties, they cause significant fogging and poor desilvering when used for photographic processing solutions. Not suitable. On the other hand, ethylene-vinyl acetate copolymer has unsatisfactory photographic performance but is usable, but its hardness is too high and causes leakage to be used in the dialysis layer.
Internal leaks sometimes occur in the demineralization chamber and concentration space, resulting in a decrease in dialysis efficiency, making it unsuitable. Therefore, only the configuration of the present invention can specifically satisfy the physical and photographic properties required for a dialysis layer rubber gasket.

Claims (1)

[Claims] 1 Photograph characterized in that when photographic processing solution waste is regenerated by ion-exchange membrane electrodialysis, the gasket of the ion-exchange membrane electrodialysis tank is made of an ethylene-propylene rubber-like copolymer. A method for recycling waste treatment liquid.