JP2019026687A - Chemical treatment method and production method of film, and production method and production device of ion exchange membrane - Google Patents

Abstract

To provide a method of preventing a foreign matter from attaching during chemical treatment of a film that is a precursor in production of a functional film such as ion exchange membrane or the like.SOLUTION: In a chemical treatment method of a film, in which the film is dipped in a dipping tank storing a chemical selected from an acidic solution and an alkaline solution, the chemical is fed from a chemical feed tank into a dipping tank and circulated through a circulation path constituted so as to return from the dipping tank to the chemical feed tank, and is subjected to a filtration operation for removing the foreign matter in the chemical at least in one point in the circulation path.SELECTED DRAWING: Figure 1

Description

  The present invention mainly relates to a method for chemical treatment of a film to obtain an ion exchange membrane, an apparatus for chemical treatment, and a method and an apparatus for producing an ion exchange membrane.

  In the process of manufacturing an ion exchange membrane such as an electrolyte membrane, a chemical treatment may be performed in which the film is immersed in a chemical solution such as a strong acid or a strong alkali.

  Patent Document 1 discloses an apparatus for providing a treatment liquid heating mechanism and a treatment liquid circulation mechanism in a liquid treatment unit, and performing a chemical treatment while heating and circulating the treatment liquid to a desired temperature. It is described that when an electrolyte membrane is produced, an operation of converting an ionic group into an acid form by immersion in sulfuric acid is described.

  In Patent Document 2, in the production of a polymer electrolyte membrane, in order to convert an ionic group from a salt type to an acid type to impart ion conductivity, the films are sequentially immersed in a plurality of immersion tanks filled with an acidic solution. On the other hand, a chemical solution treatment method for a polymer electrolyte membrane is described in which an acidic solution is continuously fed while overflowing in a cascade manner in a direction opposite to the film conveyance direction.

In Patent Document 3, hydrolysis is performed by sequentially immersing an F-type electrolyte resin (terminal group is —SO ₂ F) in an alkaline solution and an acidic solution to obtain an H-type electrolyte resin (terminal group is —SO ₃ H). A method for producing an electrolyte membrane is described.

JP 2011-194593 A JP 2013-56993 A Japanese Patent Laid-Open No. 2006-81682

  When such an ion exchange membrane is applied to a precise application, it is necessary to prevent adhesion of foreign matters as much as possible. Countermeasures such as installing in a clean environment are taken for airborne dust adhering during air transport, and measures such as electrostatic removal of the film are taken to prevent airborne dust from adhering. However, even with such measures, the problem of foreign matter adhesion has not been sufficiently solved.

  An object of the present invention is to prevent adhesion of foreign matters during chemical treatment of a film serving as a precursor, particularly in the production of an ion exchange membrane.

This invention for solving the said subject is described in following (1)-(15).
(1) In the chemical treatment method for a film, wherein the film is immersed in an immersion tank in which a chemical selected from an acidic solution and an alkaline solution is stored,
The chemical liquid is circulated through a circulation path configured to be supplied from the chemical liquid supply tank to the immersion tank and to be refluxed from the immersion tank to the chemical liquid supply tank again.
A chemical treatment method for a film, comprising performing a filtering operation to remove foreign substances in the chemical solution at least at one place in the circulation path.
(2) The chemical solution treatment method for a film according to (1), wherein the filtration operation is performed in a route in which the chemical solution is pressurized and fed by a liquid feed pump in the circulation route.
(3) The chemical treatment method for a film according to (1) or (2), wherein the filtration operation is performed with a filter having long-term resistance to the chemical.
(4) The chemical solution of the film according to any one of (1) to (3), wherein the chemical solution is refluxed to the chemical solution supply tank so that the chemical liquid overflowed from the immersion tank flows into the supply tank. Processing method.
(5) The film chemical solution according to (4), wherein the film is immersed in the immersion tank while being continuously conveyed, and the overflow is performed in a direction parallel to the film surface and perpendicular to the film conveyance direction. Processing method.
(6) The chemical solution treatment method for a film according to any one of (1) to (5), wherein the film is a precursor membrane of a cation exchange membrane having an anionic group, and the chemical solution is an acidic solution. .
(7) The chemical solution treatment method for a film according to any one of (1) to (5), wherein the film is a precursor film of an anion exchange membrane having a cationic group, and the chemical solution is an alkaline solution. .
(8) A method for producing an ion exchange membrane, comprising a step of subjecting a film to chemical treatment by the chemical treatment method for a film according to any one of (1) to (6).
(9) A film chemical treatment apparatus for immersing a film in an immersion tank in which a chemical liquid selected from a strong acid solution and a strong alkaline solution is stored, wherein the chemical liquid is supplied from the chemical liquid supply tank to the immersion tank, and A chemical solution treatment of a film having a circulation path configured to be recirculated from the immersion tank to the chemical solution supply tank, and having a chemical filtration mechanism for removing foreign substances in the chemical liquid in at least one place in the circulation path apparatus.
(10) The chemical treatment apparatus for a film according to (9), wherein the chemical filtration mechanism is installed in a path through which the chemical is pressurized and fed by a liquid feed pump.
(11) The chemical treatment apparatus for a film according to (9) or (10), wherein the chemical filtration mechanism is a chemical filtration mechanism including a filter having long-term resistance to the chemical.
(12) The film according to any one of (9) to (11), wherein the chemical liquid is refluxed to the chemical liquid supply tank by configuring the chemical liquid that has overflowed from the immersion tank to flow into the chemical liquid supply tank. Chemical processing equipment.
(13) The chemical treatment apparatus for a film according to (11), wherein the filter is a filter having long-term chemical resistance to a strongly acidic solution having pH = −0.6.
(14) The chemical treatment apparatus for a film according to (11), wherein the filter is a filter having a long-term chemical resistance to a strong alkali solution having a hydroxide ion concentration pKa = −0.6.
(15) An apparatus for producing an ion exchange membrane, including the chemical treatment apparatus for a film according to any one of (9) to (14).

  According to the present invention, the adhesion of foreign matter to the film during chemical treatment is reduced. As a result, damage and defects of the film due to foreign matters are reduced, and the quality of the finally obtained film can be improved.

It is a figure which shows one Embodiment of the chemical | medical solution processing method of this invention. It is a figure which shows one Embodiment of the chemical | medical solution processing method of this invention using a some immersion tank. It is a schematic diagram which shows one Embodiment of the chemical | medical solution processing apparatus of this invention.

  Hereinafter, the chemical treatment method for a film and the chemical treatment apparatus for a film of the present invention will be described with reference to the embodiments shown in FIGS. 1 to 3 as appropriate, but these embodiments do not limit the present invention. Absent.

  The chemical treatment method and chemical treatment apparatus for a film of the present invention are not particularly limited, but typically, for acid treatment or alkali treatment on a precursor membrane of an ion exchange membrane containing a polymer having an ionic group. Applied. A precursor film | membrane shall refer to the film used as an ion exchange film by performing the process which combined the acid process or the alkali process, or these processes. Moreover, a chemical | medical solution shall point out an acidic solution and an alkaline solution.

For example, in the production of a cation-conducting electrolyte membrane that is one form of a cation exchange membrane, as shown in Patent Document 2, the acid group of the precursor membrane in a metal salt form is acid-treated by acid treatment. By converting into a cation conductive electrolyte membrane. In the production of an anion-conducting electrolyte membrane, which is also a form of anion exchange membrane, an alkali treatment is applied to a precursor membrane in which an anion (anion) is ionically bonded to a cationic group to form a salt form. Thus, the anion is removed to form an anion conductive electrolyte membrane. In addition, in the production of a fluorine-based cation conductive electrolyte membrane, as shown in Patent Document 3, an —SO ₂ F group (fluorosulfuric acid anion group) is treated with an alkali to form —SO ₃ ^— group (sulfonic acid group). ), And then further converted to an acid sulfonic acid group (—SO ₃ H) by acid treatment. The chemical treatment method of the present invention can be applied to both acid treatment and alkali treatment in at least these cases.

  In the following, the present invention will be further described by way of an example of a chemical treatment for producing an ion exchange membrane, but the present invention is not limited to this, and any combination of the components specifically described. And the aspect applied to films other than an ion exchange membrane can also be regarded as invention.

  The basic skeleton of the polymer contained in the ion exchange membrane produced according to the present invention is not particularly limited. Preferred examples include fluorine-based polymers such as perfluoroalkylene, polyphenylene oxide, polyether ketone, and polyether ether ketone. , Polyethersulfone, Polyetherethersulfone, Polyetherphosphine oxide, Polyetheretherphosphine oxide, Polyphenylene sulfide, Polyamide, Polyimide, Polyetherimide, Polyimidazole, Polyoxazole, Polyphenylene, etc. Is mentioned. Moreover, the polymer or copolymer obtained by superposing | polymerizing styrene, ethyl styrene, vinyl pyridine, vinyl pyrazine, divinyl benzene, divinyl toluene, divinyl xylene, trivinyl benzene etc. is also mentioned. The polymer having an ionic group is a polymer in which an ionic group is bonded to such a basic skeleton.

  The ionic group is roughly classified into a cationic group and an anionic group. In the cation exchange membrane having cation conductivity, a polymer having an anionic group is used, and the anionic group and the cation form an ion pair to have a cation exchange ability. In the anion exchange membrane having anion conductivity, a polymer having a cationic group is used, and the cationic group and the anion form an ion pair, thereby having anion exchange ability.

The anionic group of the polymer having an anionic group is not particularly limited as long as it has a cation exchange ability and exhibits cation conductivity. Preferred examples of the anionic group include a sulfonic acid group (—SO ₂ (OH)), a sulfuric acid group (—OSO ₂ (OH)), and a sulfonimide group (—SO ₂ NHSO ₂ R (R represents an organic group). )), Phosphonic acid groups (—PO (OH) ₂ ), phosphoric acid groups (—OPO (OH) ₂ ), carboxylic acid groups (—CO (OH)), perfluorosulfonic acid groups (—O— (CF _{2) n SO 2 (OH)} ) can be exemplified. Further, the polymer having an anionic group may have two or more of these groups. Since the polymer having an anionic group has a high hydrogen ion conductivity, it is more preferable to have a perfluorosulfonic acid group, a sulfonic acid group, a sulfonimide group, a sulfuric acid group, or a phosphonic acid group. Most preferably, it has a perfluorosulfonic acid group or a sulfonic acid group from the viewpoint of degradability.

  The cationic group of the polymer having a cationic group is not particularly limited as long as it has anion exchange ability and exhibits anion conductivity. Preferable examples of the cationic group include a tertiary amino group, a quaternary ammonia group, a tertiary phosphonium group, and a quaternary hostnium group. The polymer having a cationic group may have two or more of these groups. The polymer having a cationic group preferably has either a quaternary ammonia group or a quaternary phosphonium group because of its high hydroxide ion conductivity.

  In general, in the production of an ion exchange membrane, most of the ionic groups in the precursor membrane are finally removed by ion exchange by acid treatment or alkali treatment (hereinafter referred to as “impurity ions”). Exists in the form of an ion-bonded salt. Since the impurity ions are difficult to remove by washing, the ion exchange membrane is finally obtained by ion exchange by acid treatment or alkali treatment.

  For example, in a polymerization reaction of a polymer having an anionic group or an addition reaction in which an anionic group is introduced into the polymer, a metal cation is used as a catalyst. Remains as. Examples of such metal cations include Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, and W cations. Among them, alkali metal or alkaline earth metal cations are often used. Furthermore, from the viewpoint of cost and environmental load, cations of Li, Na, K, Ca, Sr, and Ba are preferably used, and cations of Li, Na, and K are most preferably used.

  Similarly, in the synthesis reaction of a polymer having a cationic group, an anion (anion) which is a counter ion of a metal cation used as a reaction catalyst and a cationic group in the polymer form an ionic bond, Anions remain as impurity ions in the precursor film. Examples of such anions include sulfate ions, nitrate ions, halogen ions, carbonate ions, and bicarbonate ions. When a cationic group is introduced into a polymer by a polymer reaction, a halogenoalkyl group is often used as a functional group that exchanges with the cationic group. In this case, halogen ions such as chloride ions and fluoride ions are used in the polymer. An ionic bond is formed with the cationic group therein and remains as impurity ions in the precursor film.

  Although not particularly limited, typically, in the precursor membrane, 50% or more of the ion exchange capacity of the ion exchange membrane is present in a state of being bonded to impurity ions.

  In the chemical treatment, impurity ions contained in the precursor film are removed by ion exchange. Typically, a precursor film having an anionic group is liquid-treated with an acidic solution and ion-exchanged with hydrogen ions to form a cation exchange film, and a precursor film having a cationic group is liquid in an alkaline solution. It is processed and ion exchanged with hydroxide ions to form an anion exchange membrane. Alternatively, a precursor film having a cationic group can be liquid-treated with a weak acid solution such as carbonic acid, and ion-exchanged to carbonate ions or hydrogen carbonate ions to form an anion exchange membrane. Although not particularly limited in the present invention, the ion exchange may be performed after the chemical solution treatment so that the ionic group present in the salt state is 0.1% or less of the ion exchange capacity of the ion exchange membrane. preferable.

  The method of immersing the precursor film in the chemical solution in the immersion tank is not particularly limited, but a method of immersing the elongated precursor film while continuously conveying is preferable. In the embodiment shown in FIG. 1, a long film (precursor film) wound in a roll shape is continuously conveyed to an immersion tank and immersed in a chemical solution. In addition, although the method of cut | disconnecting a precursor film | membrane into a sheet | seat and immersing in a dipping tank by a batch type can also be used, the method performed while conveying continuously from a viewpoint of productivity is preferable. The precursor film that is continuously transported may be a single film, or may be in a state of being stuck on a transport film for the purpose of facilitating handling or when the strength is insufficient. For the purpose of further enhancing the durability of the membrane, it may be a porous membrane or a precursor membrane reinforced with a filler.

  The acidic solution used for the chemical treatment as described above is not particularly limited as long as it is a dilute solution of a strong acid, but an aqueous solution of an inorganic acid such as hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid is preferable, and particularly in terms of productivity and workability. To sulfuric acid is preferred. The water used when diluting the strong acid is preferably purified water, distilled water, RO water or deionized water from which cationic impurities are removed and reduced.

  It is preferable to use an acidic solution having a pH of 0.3 or less as the acidic solution. An indication that the ion exchange membrane exhibits excellent performance is that the ion exchange capacity is 0.5 meq / g or more, more preferably 1.0 meq / g or more, and even more preferably 2.0 meq / g or more. Assuming that the specific gravity of the film is 1, the hydrogen ion concentrations are 0.5 mol / liter or more, 1.0 mol / liter or more, and 2.0 mol / liter or more, respectively. When this hydrogen ion concentration is converted into pH, pH = 0.3 or less, pH = 0.0 or less, and pH = −0.3 or less, respectively. In order to obtain an ion exchange membrane having excellent performance, it is more preferable to use an acidic solution with pH = 0.0 or less, and it is more preferable to use an acidic solution with pH = −0.3 or less.

  The alkaline solution used for the chemical treatment as described above is preferably an alkaline solution having a pKa = 0.3 or less defined by the hydroxide ion concentration. The hydroxide ion concentration for obtaining the above-described ion exchange capacity is 0.5 mol / liter or more, more preferably 1.0 mol / liter or more, and further preferably 2.0 mm / liter or more. When this ion concentration is converted into pKa, pKa = 0.3 or less, pKa = 0.0 or less, and pKa = −0.3 or less, respectively. In order to produce an ion exchange membrane having excellent performance, it is more preferable to use an alkaline solution having a pKa of 0.0 or less, and even more preferable to use an alkaline solution having a pKa of −0.3 or less.

  In the present embodiment, the film (precursor film) before the chemical treatment is unwound by the unwinding mechanism and conveyed to the immersion tank, and is immersed in the above-described chemical liquid in the immersion tank and subjected to the chemical treatment.

  The chemical solution supply tank is a tank for storing a chemical solution to be supplied to the immersion tank. The chemical solution supply tank continuously supplies the chemical solution from the chemical solution supply tank to the immersion tank, and continuously from the immersion tank to the chemical solution supply tank. In this way, it is connected to the immersion tank by a circulation path composed of two paths, a reflux path through which the chemical solution is refluxed. And in the chemical | medical solution processing method of this invention, the filtration operation which removes the foreign material in a chemical | medical solution is performed in at least one place of a circulation path. In other words, the chemical treatment apparatus of the present invention has a chemical filtration mechanism for removing foreign substances in the chemical at at least one location in the circulation path.

  The foreign matter in the chemical liquid is a solid that causes a quality defect due to damage caused by pressing on the film or adhesion to the film, and the shape thereof is various such as granular or fibrous. As a filtration operation (filtration mechanism) for removing these foreign substances, it is preferable that the filtration size defined by a capture rate of 90% is at least 1 μm to 5 μm. This is because if the filtration size is less than 1 μm, the filtration operation becomes complicated, and if it exceeds 5 μm, fatal damage to the film tends to occur.

  In the embodiment shown in FIG. 1, the chemical solution is filtered by a filtration mechanism installed in the middle of the supply path in the process of being fed from the chemical solution supply tank to the immersion tank by a liquid feed pump installed in the supply path. receive. The filtration mechanism may be installed in the supply path or the reflux path, but in any case, it is preferably installed in the path where the chemical solution is pressurized and fed by the liquid feed pump. This is because the chemical liquid is pressurized, so that when using a filter with a small filtration size that easily becomes clogged due to a pressure loss during the filtration operation, the additional pressure operation can be omitted and it becomes simple.

  The filtration operation is preferably performed with a filter having long-term resistance to the chemical solution. This is because, when the chemical treatment is continuously performed or when the filter is continuously operated for a long period of time, foreign matter capture is hindered when the filter deteriorates. A filter having a long-term resistance to a chemical solution has a long-term resistance of 6 months or more to an acidic solution having a pH = 0.3 or less or an alkaline solution having a hydroxide ion concentration of pKa = 0.3 or less depending on the type of the chemical solution used. It is preferable that the filter has More preferably, it is a filter having a long-term resistance of 6 months or more to an acidic solution having pH = 0.0 or less or an alkaline solution having pKa = 0.0 or less, and more preferably an acidic solution having pH = −0.3 or less. Alternatively, it is a filter having a long-term resistance of 6 months or more to an alkaline solution of pKa = −0.3 or less. Furthermore, in order to cope with the chemical solution treatment of a functional film having an extremely excellent ion exchange capacity of 4 meq / g, an alkaline solution having a pH = −0.6 or a hydroxide ion concentration pKa = −0.6. Most preferably, the filter has a long-term resistance of 6 months or more to the solution.

  When the chemical treatment is continuously performed or when the filter is replaced during continuous operation over a long period of time, the chemical treatment apparatus is stopped. Therefore, it is preferable to perform the filtration operation by a filtration mechanism in which two or more filters are arranged in parallel, since continuous operation is possible even during filter replacement.

  For the purpose of grasping the circulation supply status of the chemical liquid and detecting the blockage of the filter, it is preferable to provide a flow meter having a long-term chemical liquid resistance equivalent to that of the filter. More preferably, it is a flowmeter that measures the chemical flow rate in the chemical pipe without contacting the chemical liquid. This is because if installed outside the chemical pipe having a long-term chemical resistance equal to or greater than that of the filter, there is no concern about deterioration of the flowmeter due to the chemical, and it can be used for both acidic solutions and alkaline solutions. Non-contact flowmeters using electrostatic capacity or ultrasonic waves can be used.

  The reflux of the chemical liquid from the immersion tank to the chemical liquid supply tank may be performed by using a liquid feed pump similar to that in the supply path, but it is preferable that the chemical liquid overflowed from the immersion tank is configured to flow into the chemical liquid supply tank. . This is because floating foreign substances tend to be generated on the surface of the chemical solution in the immersion tank due to the falling dust in the immersion tank, and the floating foreign substances can be easily removed from the immersion tank by overflowing the chemical solution. The direction in which the chemical overflows from the immersion tank is more preferably parallel to the film surface and perpendicular to the film transport direction when the film is immersed while being continuously transported as described above. This is because the floating foreign matter moves and becomes difficult to adhere to the film surface.

  In the chemical solution treatment method of the present invention, when chemical treatment is sequentially performed using a plurality of immersion tanks, it is preferable to provide a chemical solution supply tank and a circulation path in each immersion tank and perform the chemical liquid circulation and filtration operations independently of each other.

  In an example of the chemical treatment method of the present invention using a plurality of immersion tanks shown in FIG. 2, the unwound film is sequentially subjected to chemical treatment in the immersion tank (1), the immersion tank (2), and the immersion tank (3). The And between the chemical solution supply tank (1) and the immersion tank (1), between the chemical solution supply tank (2) and the immersion tank (2), and between the chemical solution supply tank (3) and the immersion tank (3), respectively. Are provided with a circulation path and a filtration mechanism. Then, the new chemical solution is supplied from the new chemical solution tank to the chemical solution supply tank (3), and the surplus chemical solution in the chemical solution supply tank (3) is sent to the chemical solution supply tank (2), and the chemical solution supply tank (2) The surplus chemical liquid is fed to the chemical liquid supply tank (1), the surplus chemical liquid in the chemical liquid supply tank (2) is fed to the chemical liquid supply tank (1), and the surplus chemical liquid is sent to the chemical liquid supply tank (1). The resulting chemical is sent to the waste liquid treatment unit as waste liquid. That is, it has a cascade type liquid feeding mechanism that feeds a chemical solution from a chemical solution supply tank provided in the downstream immersion tank to a chemical solution supply tank provided in the upstream immersion tank. Therefore, it is possible to reduce the amount of the chemical solution used and to increase the efficiency of the manufacturing process because it is not necessary to exchange the chemical solution for each liquid treatment tank. Such a liquid feeding mechanism is preferably realized by configuring so that the chemical liquid overflowing from the downstream chemical liquid supply tank flows into the upstream chemical liquid supply tank, but is configured to send liquid using a liquid feed pump. May be. Further, it is preferable that the chemical liquid overflowing from the most downstream chemical liquid supply tank flows into the waste liquid treatment unit as waste liquid.

  It is preferable that the chemical liquid circulation path in each immersion tank includes a mechanism for individually controlling the liquid feeding speed. This is because it becomes easy to select an appropriate filtration filter according to the size of the foreign matter to be removed, and to adjust the liquid feeding amount in accordance with the usage time of the filtration filter.

  FIGS. 3A and 3B are schematic views of the chemical processing apparatus of the embodiment in which the direction in which the chemical overflows from the immersion tank to the chemical supply tank is parallel to the film surface and perpendicular to the film transport direction. is there. In FIG. 3A, the film transport direction is a direction from the front side to the back side. The chemical solution is fed from the chemical solution supply tank 1 to the filtration mechanism 3 using the pressurized liquid feed pump 2 to remove foreign substances, the chemical solution supply amount is measured by the flow meter 4, and the chemical solution is supplied to the immersion tank 5. The film M is conveyed to the immersion tank 5 by a conveyance roller (in liquid) 6 and a conveyance roller (upper part) 7. Then, the chemical liquid overflows from the immersion tank in a direction parallel to the film surface of the film M, and circulates in the chemical liquid supply tank. As a result, the floating foreign matter also moves parallel to the film surface of the film M, and is quickly removed from the immersion tank. In FIG. 3A, the overflow direction 8 is the right side of the page, and the flow of the chemical at that time is indicated by 11. In this case, the suspended foreign matter removed from the immersion tank is once accumulated in the chemical solution supply tank, but when these suspended foreign substances are immersed in the liquid, they are collected one after another by the filtration mechanism 3.

  Even when multiple immersion tanks and multiple chemical supply tanks are provided, the chemical supply tanks are arranged so that the chemicals overflow from all immersion tanks in the direction parallel to the film surface by arranging them in the film transport direction. Is possible. Here, the film transport direction is the direction in which the film is transported when the ion exchange membrane manufacturing apparatus is viewed from directly above. FIG. 3B is a schematic view of the immersion tank 5 and the chemical liquid supply tank 1 of the chemical liquid processing apparatus according to the embodiment as viewed from above. The film transport direction 9 in FIG. 3B is a direction from the bottom to the top of the page. Since the film M is submerged in the four transport rollers (upper part) 7 and the chemical liquid, the film M is transported while being sequentially processed in the three immersion tanks by a transport roller (in liquid) (not shown). Also in this embodiment, the film surface when the film M is immersed in the chemical solution and when the film M is removed from the chemical solution and the direction 8 in which the chemical solution overflows are in a parallel relationship. Furthermore, the film surface is parallel to the rotation axis direction 10 of the transport roller (upper part) 7. The direction 8 in which the chemical liquid overflows from the immersion tank 5 to the chemical supply tank 1 is a direction parallel to the film surface, so that the flow 12 on the chemical liquid surface in the immersion tank becomes a flow in substantially the same direction, and the floating foreign matter is rapidly immersed in the immersion tank. Can be excluded from the chemical solution supply tank.

  The ion exchange membrane manufacturing apparatus of the present invention is an ion exchange membrane manufacturing apparatus including the film chemical solution processing apparatus of the present invention. Typically, in the ion exchange membrane production apparatus of the present invention, following the immersion tank, a film washing unit for washing the ion exchange membrane treated with a chemical solution, a film drying unit for drying the washed film, And a film take-up unit for taking up the dried film. By continuously performing the series of steps, the quality of the continuous functional film is stabilized, and the ion exchange membrane can be mass-produced efficiently.

M: Precursor film 1: Chemical solution supply tank 2: Pressurized liquid feed pump 3: Filtration mechanism 4: Flow meter 5: Immersion tank
6: Transport roller (in liquid)
7: Transport roller (upper part)
8: Overflow direction of chemical liquid 9: Transport direction of precursor film 10: Direction of rotation axis 11: Overflow of chemical liquid 12: Flow of chemical liquid surface

Claims (15)

In the film chemical treatment method of immersing a film in a dipping tank in which a chemical selected from an acidic solution and an alkaline solution is stored,
The chemical liquid is circulated through a circulation path configured to be supplied from the chemical liquid supply tank to the immersion tank and to be refluxed from the immersion tank to the chemical liquid supply tank again.
A chemical treatment method for a film, comprising performing a filtering operation to remove foreign substances in the chemical solution at least at one place in the circulation path. The film chemical treatment method according to claim 1, wherein the filtration operation is performed in a path in which the chemical liquid is pressurized and fed by a liquid feed pump in the circulation path. The chemical solution treatment method for a film according to claim 1 or 2, wherein the filtering operation is performed with a filter having long-term resistance to the chemical solution. The chemical | medical solution processing method of the film in any one of Claims 1-3 which performs the recirculation | reflux of the chemical | medical solution to the said chemical | medical solution supply tank by comprising so that the chemical | medical solution overflowed from the said immersion tank may flow in into a supply tank. 5. The chemical treatment method for a film according to claim 4, wherein the film is immersed in the immersion tank while being continuously conveyed, and the overflow is performed in a direction parallel to the film surface and perpendicular to the film conveyance direction. The chemical solution treatment method for a film according to claim 1, wherein the film is a precursor membrane of a cation exchange membrane having an anionic group, and the chemical solution is an acidic solution. The chemical solution treatment method for a film according to claim 1, wherein the film is a precursor film of an anion exchange membrane having a cationic group, and the chemical solution is an alkaline solution. The manufacturing method of the ion exchange membrane which has the process of carrying out a chemical | medical solution process of the film by the chemical | medical solution processing method of the film in any one of Claims 1-6. A chemical treatment apparatus for a film that immerses a film in an immersion tank in which a chemical solution selected from a strong acid solution and a strong alkaline solution is stored, wherein the chemical solution is supplied from the chemical solution supply tank to the immersion tank, and the immersion tank A chemical processing apparatus for a film having a circulation path configured to be recirculated to the chemical liquid supply tank again and having a chemical filtration mechanism for removing foreign substances in the chemical liquid in at least one place in the circulation path. The chemical solution processing apparatus for a film according to claim 9, wherein the chemical solution filtering mechanism is installed in a path through which the chemical solution is pressurized and fed by a liquid feeding pump. The chemical solution processing apparatus for a film according to claim 9 or 10, wherein the chemical solution filtration mechanism is a chemical solution filtration mechanism including a filter having long-term resistance to the chemical solution. The chemical solution processing apparatus for a film according to any one of claims 9 to 11, wherein the chemical solution is refluxed to the chemical solution supply tank so that the chemical solution overflowed from the immersion tank flows into the chemical solution supply tank. The chemical treatment apparatus for a film according to claim 11, wherein the filter is a filter having a long-term chemical resistance to a strongly acidic solution having pH = −0.6. 12. The chemical treatment apparatus for a film according to claim 11, wherein the filter is a filter having a long-term chemical resistance to a strong alkaline solution having a hydroxide ion concentration pKa = −0.6. An apparatus for producing an ion exchange membrane, comprising the chemical treatment apparatus for a film according to claim 9.

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