JPH0227656B2 - HATSUSHOKUGENZOSHUYAKUOBUNRIOYOBIKAISHUSURUHOHO - Google Patents

Description

Detailed Description of the Invention Background of the Invention (a) Technical Field The present invention relates to a method for selectively separating and recovering a color developing agent from a color processing solution containing a color developing agent. This invention relates to a method for selectively separating and recovering a color developing agent from a color processing solution. (b) Prior art and its problems The color developing solution used when forming a dye image using a silver halide color photographic light-sensitive material usually contains a p-phenylenediamine color developing agent, sodium hydroxide, and carbonic acid. Alkali agents such as sodium, trisodium phosphate, sodium metaborate, borax, antioxidants such as sodium sulfite and hydroxylamine salts, development inhibitors such as potassium bromide, potassium iodide, 6-nitrobenzimidazole nitrate, etc. It contains a developer component and has a special purpose, for example, to facilitate the penetration of the oxidized color developing agent into the oil spheres containing the coupler and dispersed in the emulsion layer, and to assist in bonding with the coupler and color development. Contains an added color development accelerator such as benzyl alcohol. This color developing agent contains various compounds including a p-phenylenediamine type color developing agent, but these components can be extracted by processing a certain amount of silver halide color photographic material or during storage. The developing power gradually decreases due to oxidation and the like.
For this reason, some or all of such color developing solutions are discarded and replaced with new color developing solutions in an effort to maintain the developing power within a predetermined range. Such operations are performed not only for the color developer, but also for subsequent processing solutions such as stop solution, fixer, bleach, bleach-fix solution, and stabilizer, in order to maintain the performance of the color developer. A part of it adheres to the color photographic material and is carried into the subsequent processing solutions, and as a result is discarded together with these processing solutions. Various photographic processing solutions such as color developing solutions contain various additives including p-phenylenediamine color developing agents at fairly high concentrations.
p-phenylenediamine color developing agents meet the biochemical oxygen demand (hereinafter referred to as BOD) and chemical oxygen demand (hereinafter referred to as COD) stipulated in pollution control related laws such as the Water Pollution Control Law and the Sewerage Law. ), and when disposed of directly into sewage or rivers, it may cause environmental pollution. Therefore, when disposing of photographic processing solutions containing p-phenylenediamine color developing agents into sewage or rivers, environmental pollutants including the color developing agents must be separated and recovered from the photographic processing solutions. It is particularly necessary from the standpoint of preventing environmental pollution to render the material harmless and dispose of it, and there is a particular demand for the development of effective means for this purpose. Furthermore, p-phenylenediamine-based color developing agents are expensive, and it is not desirable from an economic standpoint to simply separate and decompose them and dispose of them. It is preferable to reuse it for development. Conventionally, various methods have been proposed and put into practical use as methods for separating color developing agents from photographic processing solutions discharged from processing steps such as color development, fixing, bleaching, and stabilization. For example, the method of separating and removing specific compounds by bringing activated carbon into contact with a photographic processing solution as described in U.S. Patent No. 3,884,983;
Extraction method using an organic solvent such as Kenshin disclosed in the specification of No. 2358053, and salting out by adding salt such as sodium sulfate to the developer disclosed in Japanese Patent Publication No. 45-33698 to separate the developing agent, etc. , a method for recovering a developing agent dissociated using an anion exchange resin as described in U.S. Pat. There is a separation and recovery method using a copolymer, and a method disclosed in JP-A-53-50737 in which a developing agent and the like are separated from a photographic processing solution by bringing the photographic processing solution into contact with a methacrylate copolymer. However, these conventionally proposed methods have various drawbacks from a practical standpoint. That is, the first adsorption removal method using activated carbon has excellent operability and ability to separate organic matter from an aqueous solution, but it has a drawback in selectivity because it adsorbs most organic matter, and moreover, the adsorption is strong. Therefore, it is not easy to separate the adsorbed substances, and the separation and purification are complicated and expensive. In addition, the second extraction method using organic solvents such as kerosene uses a large amount of flammable organic solvents, which is extremely dangerous in terms of disaster prevention and occupational safety and health.Furthermore, the cost of the solvent is high. It is not practical for several reasons. The third salting-out method using sodium sulfate, etc. requires a large amount of salt, which imposes a large economic burden. Furthermore, the operations for purifying each compound are complicated and impractical. The fourth method of using an anion exchange resin has an extremely low removal rate for p-phenylenediamine color developing agents having a small degree of dissociation and is not practical. Furthermore, the fifth and sixth methods use styrene-divinylbenzene copolymers and methacrylate copolymers to adsorb specific compounds in photographic processing solutions to these copolymers, which remove specific compounds through continuous use. In addition, there are problems in terms of disaster prevention because the adsorption rate gradually decreases and it is necessary to use a large amount of strong acid to restore the adsorption function of these resins or to elute the adsorbed substance with an organic solvent such as methanol. Furthermore, according to these conventional methods, the separated and recovered photographically useful compounds, especially p-
In order to reuse phenylenediamine-based color developing agents, extremely complicated processes such as concentration, precipitation, precipitation, and filtration, as well as extraction with organic solvents, are required, which cannot be carried out at a commercial laboratory. do not have. Purpose of the Invention The present invention has been made in view of the above circumstances, and its first purpose is to
- It is an object of the present invention to provide a method for selectively separating a p-phenylenediamine color developing agent from a liquid containing a phenylenediamine color developing agent (hereinafter referred to as the liquid according to the present invention). A second object of the present invention is to provide a p-phenylenediamine color developing agent that has a high ability to selectively separate and recover a p-phenylenediamine color developing agent from the liquid according to the present invention, and a p-phenylenediamine color developing agent that is separated and recovered. It is an object of the present invention to provide a cation exchange resin that can elute the main drug extremely easily and can be used continuously over a long period of time. The third object of the present invention is to separate, elute, and recover the p-phenylenediamine color developing agent selectively adsorbed by the cation exchange resin by an extremely simple operation, and reuse it as a color developing solution. The goal is to provide a way to do so. DETAILED DESCRIPTION OF THE INVENTION As a result of extensive research, the present inventors have developed a method for separating and recovering color developing agents by cation exchange of the liquid according to the present invention containing a p-phenylenediamine color developing agent and having a pH of 8 or less. It has been discovered that the p-phenylenediamine color developing agent can be selectively separated and recovered from the liquid by contacting it with a resin, leading to the completion of the present invention. Cation exchange resins advantageously used in the present invention include cation exchange resins in which functional groups such as sulfonic acid groups and phosphonic acid groups are bonded to a resin matrix. These functional groups can be used as a monofunctional resin in which only one type of functional group is bonded to the resin, or as a difunctional or polyfunctional resin in which two or more types of functional groups are bonded. The ion exchange resin to which these functional groups are bonded is preferably a copolymer of styrene and divinylbenzene (DVB), and copolymers of acrylic acid and divinylbenzene to which carboxylic acid groups are bonded, and methacrylic acid. and divinylbenzene copolymers, as well as phenol-formalin condensates with methylene sulfonic acid groups bonded to them, styrene and divinylbenzene copolymers with sulfonic acid groups, phosphonic acid groups, or iminodiacetic acid groups as functional groups, etc. can be mentioned. The chemical and physical properties of the cation exchange resin used in the present invention, such as exchange capacity, exchange reaction rate, regeneration efficiency, and mechanical strength, are determined by the functional groups used and the crosslinking agent content of the resin matrix, i.e. Depends on degree. The cation exchange resin used in the present invention is a homogeneous colorless and transparent spherical particle, which is a gel type consisting of an almost homogeneous polymer phase, and a spherical particle whose appearance is generally cloudy and has pores inside the particle.
Any porous type having an extremely large specific surface area can be used. Its use is appropriately selected depending on the type of liquid related to the present invention. In order to separate the color developing agent from the liquid containing the p-phenylenediamine color developing agent of the present invention, it is generally preferable to use a porous cation exchange resin that is porous and has a large specific surface area. Specifically, among the above porous cation exchange resins, the total pore volume is 0.1 to 3 ml/g and the specific surface area is about 1 to 2000 m ² /g.
g range is preferred. The cation exchange resin of the present invention having a total pore volume and specific surface area within the above ranges is manufactured by Rohm & Haas Co., Ltd.
Amber light released by Hass)
IR-120, Amberlite IR-116, Amberlite IR-118, Amberlite IRC-50, Amberlite IRC-718; Duolite C-20, C-250, C-26 from Diamond Syamrock Co., Ltd.
C-3, ES-63; DIAION SK102, PK208, WK10, manufactured by Mitsubishi Chemical Industries, Ltd.
Specific examples include WA20 and CR10. However, the cation exchange resin used in the present invention is not limited to those specifically listed above, and other cation exchange resins can also be preferably used. Contained in the liquid according to the present invention, selectively separated from the liquid by the cation exchange resin of the present invention,
The recovered p-phenylenediamine color developing agents include, for example, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-
Methyl-4-amino-N-ethyl-β-methanesulfonamidoethylaniline, 4-amino-N,
N-diethylaniline, N-ethyl-N-β-
(β-methoxyethoxy)ethyl-3-methyl-
Included are 4-aminoaniline and salts thereof such as sulfate, hydrochloride, p-toluenesulfonic acid, and the like. Regarding color developer 1, when using these for color development processing of color photographic light-sensitive materials,
Concentrations from 0.1 g to about 30 g, more preferably from 0.3 to about 15
Contained at a concentration of g. Further, the above color developing agents may be contained alone or in a mixture of two or more. The color development according to the present invention includes, in addition to the above-mentioned color developing agent, an alkaline agent commonly used in color developing solutions;
For example, it may contain sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, borax, etc., and may further contain various additives, such as benzyl alcohol, alkali metal halides, such as potassium bromide, potassium chloride, etc., or development control. The agent may include, for example, citradinic acid, and the preservative may include hydroxylamine, sulfite, and the like. Furthermore, the p-phenylenediamine color developing agent that is selectively separated and recovered from the photographic processing solution according to the present invention is not only present in the color developing solution, but also exists in the bleaching bath that follows the color development processing. They are carried into various processing baths such as washing baths, fixing baths, bleach-fixing baths, and stabilization baths by means of treated films. Therefore, the photographic processing solution processed using the cation exchange resin of the present invention is not only a color developing solution, but also a color developer used in various steps of bleaching and fixing silver halide color light-sensitive materials, and other auxiliary steps. Includes all photographic processing solutions. The embodiment in which the p-phenylenediamine color developing agent of the present invention is separated and recovered from the liquid according to the present invention is not limited as long as the liquid according to the present invention is brought into contact with the cation exchange resin. For example, cation exchange resins may be present in various photographic processing baths such as color developing baths, bleaching baths, fixing baths, washing baths, stabilizing baths, etc., or the photographic processing solution overflowing from these baths may be present in one or more locations. The cation exchange resin may be collected in a tank provided at a certain location, and the cation exchange resin may be present in the tank. In this case, the processing of the photographic processing solution with the cation exchange resin may be carried out either batchwise or continuously. The method of contacting the photographic processing solution containing the p-phenylenediamine color developing agent with the cation exchange resin of the present invention can be any of the conventionally well-known methods for industrial wastewater treatment using ion exchange resins. In particular, a cylindrical container is filled with the cation exchange resin of the present invention, and a photographic processing solution containing a p-phenylenediamine color developing agent is passed from the top to the bottom or from the bottom to the top. The so-called column method is the simplest and has the best contact efficiency. However, in addition to the fixed bed method mentioned above, the method of contact between the photographic processing solution and the cation exchange resin used in the present invention is mainly a fluidized bed method or a moving bed method in which the cation exchange resin is continuously fluidized or moved. Particularly suitable for large-scale processing. When employing this fluidized bed method, it is preferable to introduce a cation exchange resin from above the column and pass a photographic processing solution upwardly from below the column to bring about countercurrent contact. Furthermore, when a moving bed method is adopted to separate and recover the p-phenylenediamine color developing agent from the photographic processing solution of the present invention, a method may be used in which a moving bed of cation exchange resin is raised or lowered. .
In this case, the number of columns may be one or more, and processing, regeneration (elution), and washing may be performed within the same resin column using one column, or multiple columns may be used. It is also possible to perform processing (separation of color developing agent), regeneration, washing, etc. in separate columns. The method of the present invention can be applied to color negative film, color paper, color positive film, color reversal film for slides, color reversal film for movies,
It can be applied to any photographic processing solution containing a color developing agent for silver halide color photographic materials such as TV color reversal films and reversal color paper. In order to selectively separate and recover the p-phenylenediamine color developing agent from the photographic processing solution by contacting these photographic processing solutions with a cation exchange resin, the photographic processing solution must be brought into contact with a cation exchange resin under conditions where the photographic processing solution has a pH of 8 or less. contact with the cation exchange resin is necessary. Therefore, in order to separate and recover the color developing agent from a color developer whose photographic processing solution has a pH of 10 or higher, it is necessary to adjust the photographic processing solution to a pH of 8 or lower before contacting it with the cation exchange resin. be. Also,
P contained in the stop solution and fixing solution, which generally has a pH of 8 or less.
- When separating and recovering the phenylenediamine-based color developing agent, it can be brought into contact with the cation exchange resin of the present invention either as is or after adjusting to a predetermined pH. The optimum pH of a photographic processing solution varies depending on the type, concentration, salt concentration of the color developing agent contained in the processing solution, the type of functional group bonded to the resin matrix of the cation exchange resin, etc., but generally the pH is 1 to 8. The object of the present invention can be achieved using a photographic processing liquid whose pH is particularly preferably adjusted to a range of PH1 to 5. The p-phenylenediamine color developing agent can be efficiently separated and recovered when the salt concentration is 0.3 mole or less, preferably 0.2 mole or less, particularly preferably 0.05 mole or less. The acid used to adjust the pH of the photographic processing solution of the present invention to 8 or lower is preferably sulfuric acid, hydrochloric acid, acetic acid, etc., but various acids commonly used in photographic processing can also be used. these are,
They may be used alone or in combination of two or more. By the method of the present invention, the p-phenylenediamine color developing agent selectively adsorbed by the cation exchange resin can be easily desorbed from the cation exchange resin using an alkaline solution having a pH of 9 or higher. The p-phenylenediamine color developing agent desorbed by the alkaline solution is recovered and reused as a component of the color developer. The alkaline agent used to desorb the p-phenylenediamine color developing agent adsorbed on the cation exchange resin includes any alkaline agents commonly used in the photographic field, such as caustic alkali, potassium carbonate, and sodium carbonate. is included. In addition, borates and phosphates may be used as alkaline agents. Among the above alkaline agents, alkali carbonate is preferred from the viewpoints of ease of handling, low cost, and environmental pollution. In order to prevent the oxidation and decomposition of the developing agent, the alkaline solution containing the p-phenylenediamine-based color developing agent desorbed from the cation exchange resin is treated with thotrium sulfite, potassium bisulfite, sodium hydrogen sulfite, hydroxylamine salt, hydroxyl Preservatives known in the photographic field such as amine derivatives can be used alone or in combination of two or more. When carrying out the method of the present invention, it is practically best to use the overflow color developing solution as an alkaline solution to recover and reuse the p-phenylenediamine color developing agent adsorbed on the cation exchange resin. preferable. In this case, the overflowing color developer is
It can be used as an alkaline solution as it is, or after removing unnecessary components such as bromide ions by an anion exchange resin method or an electrodialysis method. In any case, in order to reuse the overflowing color developing solution, it is necessary to add the missing components to adjust the concentration and pH to a predetermined value. Specific Effects of the Invention According to the method of the present invention, a p-phenylenediamine color developing agent in a photographic processing solution is selectively replaced with other cations (for example, those contained in the photographic processing solution) using a cation exchange resin. The adsorbed ^{p -} phenylenediamine color developing agent can be easily separated with an alkaline agent and reused as a color developing solution. can do. Therefore, according to the method of the present invention, p
- Like phenylenediamine color developing agents, they exist in a diluted state in acidic solutions such as sulfuric acid and hydrochloric acid, or in large amounts of organic solvents, and from this state, color developing agents cannot be used for their original purpose. To achieve this, no complicated chemical treatments are required, and the p-phenylenediamine color developing agent can be easily and easily separated from the photographic processing solution, recovered, and reused at a commercial laboratory. The economic value is extremely large. In addition, in the present invention, as a preferred embodiment, color development, which is generally used in image forming processing of silver halide color photographic light-sensitive materials,
Although the selective separation and recovery of color developing agents present in photographic processing solutions resulting from various processing steps such as bleaching, fixing, bleach-fixing stabilization, termination, and water washing has been described, The solution to be used is not just a photographic processing solution, but any solution containing a p-phenylenediamine color developing agent, such as a solution recovered from the above-mentioned anion exchange resin, or a concentrated or diluted solution collected by electrodialysis. etc. are also included. Specifically, as proposed in U.S. Pat. No. 3,253,920, a color developing solution is brought into contact with an anion exchange resin to remove halogen ions from the solution, and then a small amount of halogen ions adsorbed on the anion exchange resin are removed. Aqueous solutions of sulfuric acid, sodium chloride, carbonic acid, etc. used to desorb color developing agents are also applicable to the processing liquid of the present invention. Also, Unexamined Japanese Patent Publication No. 1973-
No. 82235, Japanese Patent Application Publication No. 53-50737 or US Patent No.
The final acidic aqueous solution obtained by the color developing agent recovery method described in No. 2358053 is also a target of the processing solution of the present invention. Specific Examples of the Invention The present invention will be explained in more detail with reference to Examples below, but the embodiments of the present invention are not limited thereto. Example 1 A color developing solution (salt concentration: about 0.3 ml/) containing each of the following components was prepared, and the color developing solution was diluted to the salt concentration shown in Table 1 and the pH was adjusted. A column filled with 20 ml of the various cation exchange resins of the present invention shown in 1 was flowed from top to bottom at a flow rate of 8 ml/min to determine the adsorption capacity of p-phenylenediamine color developing agents to the various cation exchange resins (g/resin 1). ). As comparative examples, Amberlite XAD-7 and Amberlite 400, which are not of the present invention, were used. Table of results-1
Shown below. Color developer Potassium carbonate 30g Sodium bicarbonate 2.5g Potassium sulfite 5g Sodium bromide 1.2g Potassium iodide 1.5mg Hydroxylamine sulfate 2.5g Sodium chloride 0.3g Sodium diethylenetriaminepentaacetate 2.5g 4-Amino-3-methyl-N- Ethyl-N-(β
-Hydroxyethyl)-aniline sulfate (CD-
4) 4.6g PH 10.06

【table】

【table】

[Table] From the results in Table 1, it can be seen that a color developing solution containing a p-phenylenediamine color developing agent and having a pH of 8 or less is largely adsorbed when it comes into contact with the cation exchange resin. Example 2 In order to recover the color developing agent (CD-4) adsorbed on Duolite C-26 (macroporous strongly acidic cation exchange resin) of Example 1, an alkaline agent (eluent) shown in Table 2 was used. ) was used to investigate its elution effect. The alkaline solution containing the alkaline agent shown in Table 2 was allowed to flow down the column at a flow rate of 4 ml/min. The results are shown in Table-2.

Adjust with [Table].
Reference example: NCV-36 automatic processor (manufactured by Noritsu Koki Co., Ltd.)
Sakura Color negative film was continuously processed using a series of processing steps shown below.

[Table] Color development of the Sakura Color negative film was carried out while replenishing the color development solution of Example 1 with the color development replenisher shown below. Composition of replenisher: Potassium carbonate 32.0g / Sodium sulfite 4.5g / Potassium bromide 0.9g / Hydroxylamine sulfate 3.2g / Color developing agent (CD-4) 5.6g / The solution is 1m long for the above 135mm color negative film. The above color negative film was processed for 1000 m by replenishing at a rate of 50 ml per film. The amount of overflow liquid flowing out from the color developing bath into the stock tank due to the replenishment of the color developing replenisher was 47 per 1000 m of color negative film, and the composition of the overflow liquid is shown below. This overflow liquid is replaced with a conventionally used anion exchange resin, Amberlite IRA-400 (manufactured by Rohm and Haas, strong basic anion exchange resin, exchange group - N ⁺ (CH ₃ ) ₃ Cl ^- ). into a column packed with 2
Bromine ions (Br ^- ) present in the overflow liquid were removed by flowing down at a rate of 0.2/min. The various main compositions of the overflow liquid after passing through the anion exchange resin after bromide ion removal are also shown below.

[Table] The overflow liquid after removing bromide ions is
A purified color developing agent and other necessary photographic chemicals were added to adjust the composition and concentration to be the same as those of the above replenisher to obtain 50 regenerated replenisher (1). Using this regenerating replenisher (1), color negative film (135mm
Size) 1000m was color developed and the overflow liquid was reprocessed. This cycle was repeated 50 times, and the amount of overflow liquid discarded per cycle was 7. Example 3 In this example, the color developing agent was effectively recovered and reused from the overflow liquid that was discarded in the above reference example, and a conventional anion exchange resin and the cation exchange resin of the present invention were effectively combined. This paper describes a method for effectively recovering and reusing a developing agent from a color developing solution. The overflow liquid 7 discarded in one cycle of the above reference example was diluted 10 times with water, the pH was adjusted to 2.7, and then the PH was adjusted to 2.7.
It was allowed to flow down at a flow rate of 1 min, and 34.0 g (more than 99%) of the color developing agent (CD-4) was adsorbed and separated. On the other hand, the color developing agent adsorbs the anion exchange resin passing liquid 40 shown in Table 3 below, which has been removed from the overflow liquid extracted from the color developing solution using the strongly basic anion exchange resin Amberlite IRA-400. Duolite C-26
The color developing agent (CD-4) was efficiently recovered in the solution passing through the anion exchange resin by flowing through a column filled with the above at a flow rate of 0.4/min. The composition and content after passing through this cation exchange resin Duolite C-26 are shown in Table 3. To this overflow liquid 40, the insufficient color developing agent and other necessary chemicals were added and adjusted to have the same composition and concentration as the replenisher shown in Table 3 to prepare a regenerated replenisher (50). Using this regenerated replenisher (), a total of 50 cycles of color development, separation and recovery of bromide ions and color developing agents from the overflow solution, and preparation of the regenerated replenisher from the overflow solution were performed 50 times. According to the present invention, all the color developing agent in the overflow liquid from the color developing bath can be regenerated, so that there is no loss of the color developing agent. Therefore, in 50 cycles, approximately 1.6 kg of the color developing agent (CD-4) could all be effectively reused.

[Table] In order to investigate the photographic properties (sensitivity, gamma, fog density) of the color developer (1) recycled according to the conventional method and the color developer (2) obtained according to the method of the present invention. Sakura color negative film (manufactured by Konishi Roku Photo Industries, Ltd.) was subjected to white stepwise exposure using a KS-7 type sensitometer (manufactured by Konishi Roku Photo Industries, Ltd.), and then subjected to color development processing. The transmission density of the obtained yellow (Y) image, magenta (M) image, and cyan (C) image was determined by PDA60.
Measurements were made using a photoelectric densitometer (manufactured by Konishiroku Photo Industry Co., Ltd.). The results are shown in Table-4.

[Table]
As is clear from Table 4, there are differences in the sensitivity, gamma (γ), and fog of each dye between the color developer () processed by the conventional method and the color developer () processed according to the present invention. There were no substantial differences in concentration. This means that the color developing agent in the overflow solution, which was conventionally discarded, can be reused very easily with almost no effect on photographic properties, which proves the economical efficiency. Example 4 In order to remove halogen ions in the color developing solution, the anion exchange resin shown in the reference example, Amberlite IRA-400, was passed through an overflow solution 40 containing 5.0 g/color developing agent (CD-4). The color developing agent (CD-4) was 5.0.
g/ to 4.6 g/. Therefore, in the overflow liquid 40, 16 g of color developing agent (CD-4) was adsorbed by the anion exchange resin. Next, in order to desorb the color developing agent adsorbed on this anion exchange resin, first wash this resin with water and then add 2% sulfuric acid aqueous solution 60.
The anion exchange resin was allowed to flow down at a rate of 0.6/min, and the anion exchange resin was regenerated, and the color developing agent was eluted together with the halogen ions at an efficiency of 97.5%. The concentration of CD-4 in the sulfuric acid aqueous solution was about 0.26 g/g. The thus obtained acidic sulfuric acid aqueous solution containing the color developing agent was then allowed to flow down the column of Example 3 packed with the cation exchange resin Duolite C-26 of the present invention, to adsorb and separate most of the color developing agent. . This color developing agent could be easily eluted by contacting with an overflow solution (color developing solution) passed through an anion exchange resin to remove halogen ions. A color reversal film, Sakura Chrome R-100 (manufactured by Konishiroku Photo Industry Co., Ltd.), was processed using an automatic processor E-6080 (manufactured by Noritsu Koki Co., Ltd.) according to the following processing steps. The compositions of the color developer and bleach adjustment solution used are shown below.

[Table] Color developer sodium tripolyphosphate 0.5g 1,8-hydroxy-3,6-dithiaoctane
2.0g Anhydrous sodium sulfite 7.6g Tripotassium phosphate trihydrate 36.0g Potassium bromide 0.8g 0.1% potassium iodide 28.0ml Sodium hydroxide 2.0g 4-Amino-N-ethyl-N-(β-methanesulfonamide Ethyl)-m-toluidine sesquisulfate monohydrate (CD-3) 10.5g Citrazic acid 1.35g PH11.8 Bleach adjustment solution α-monothioglycerol 0.5ml Sodium hydroxide 3.0g Sodium sulfite 10.0g Ethylenediamine 4 Acetic acid 8.0g PH6.0 Through this treatment, the amount of color developer attached to the film and carried into the bleach adjustment solution was analyzed for color developer (CD-3) using the serimetry method, and found to be 0.7g. / It was. Bleach adjustment solution (PH6.0) containing color developing agent (CD-3)10
In order to separate and recover the above-mentioned developing agent, this bleach adjustment solution was passed through a column packed with the cation exchange resin of the present invention, Ambelite IR-120 (gel-type resin exchange ion-SO ₃ ^- H ⁺ )1. 0.2 to
When the concentration of the color developing agent (CD-3) in the bleach adjustment solution after flowing out was examined, almost no color developing agent (CD-3) was detected. On the other hand, in the same manner as in Example 3, the overflow liquid 10 from the color developing bath was first treated with a conventional anion exchange resin to adsorb and remove bromide ions in the overflow liquid, and then this liquid was subjected to the bleaching treatment described above. Color developing agent in liquid (CD-3)
Amberlight IR used to remove
6.9 g (98.5%) of the color developing agent could be recovered when the color developing agent was allowed to flow through a column packed with 120 ml at a flow rate of 0.2/min.

Claims (1)

[Scope of Claims] 1. A method of contacting a liquid containing a color developing agent with a pH of 8 or less with a cation exchange resin to separate the color developing agent from the liquid. 2. A method for separating the color developing agent from the liquid according to claim 1, wherein the cation exchange resin has at least one functional group selected from a sulfonic acid group and a phosphonic acid group. . 3. The method for separating the color developing agent from the liquid according to claim 2, wherein the cation exchange resin is a styrene-divinylbenzene copolymer. 4. A method for separating the color developing agent from the liquid according to claim 1, 2 or 3, wherein the color developing agent is a p-phenylenediamine type color developing agent. . 5 The salt concentration of the liquid containing the color developing agent with a pH of 8 or less
A method for separating the color developing agent from the liquid according to claim 1, 2, 3, or 4, wherein the color developing agent is 0.05 mol/or less. 6. A method for recovering the color developing agent from the liquid by contacting a liquid with a pH of 8 or less containing a color developing agent with a cation exchange resin, and then bringing an alkaline liquid with a pH of 9 or more into contact with the cation exchange resin. 7. The method for recovering the color developing agent from the solution according to claim 6, wherein the alkaline solution having a pH of 9 or higher is a color developing solution. 8. The method for recovering the color developing agent from the liquid according to claim 6 or 7, wherein the cation exchange resin is a styrene-divinylbenzene copolymer. 9. A method for recovering the color developing agent from the liquid according to claim 6, 7 or 8, wherein the color developing agent is a p-phenylenediamine type color developing agent. . 10 From the liquid according to claim 6, 7, 8 or 9, the salt concentration of the liquid having a pH of 8 or less and containing a color developing agent is 0.05 mol/or less. A method for recovering color developing agents.