JP5137896B2 - Electric deionized water production apparatus and deionized water production method - Google Patents

Description

  The present invention relates to a technique for an electric deionized water production apparatus and a deionized water production method used in various industries such as semiconductors, liquid crystals, pharmaceuticals, and food industries, consumer use, and research facilities.

  As a method for producing deionized water, a method of performing deionization by passing water to be treated through an ion exchange resin has been known. However, in this method, when the ion exchange resin is saturated with ions, regeneration is usually performed with a drug. Such regeneration treatment is disadvantageous in processing operation, and in order to eliminate such a point, a deionized water production method by an electric deionization method that does not require regeneration by a chemical agent has been established and has been put into practical use. .

  In an electric deionized water production apparatus (EDI) that performs such desalting treatment, an ion exchanger is partitioned between an anode and a shade by a cation exchange membrane on one side and an anion exchange membrane on the other side. And a concentrating chamber on both sides of the desalting chamber via a cation exchange membrane and an anion exchange membrane. Usually, a plurality of sets of desalting chambers and concentrating chambers are arranged. When deionized water is produced by an electric deionized water production apparatus, water to be treated is placed in a demineralization chamber filled with an ion exchanger in a state where a direct current is passed between the anode and the cathode. By passing the concentrated water, ions in the water to be treated are moved into the concentrated water to obtain deionized water.

  Here, when the hardness of the water to be treated flowing into the desalination chamber is high, for example, when tap water or water obtained by subjecting tap water to RO membrane treatment is used as the water to be treated, a hardness scale is formed on the anion exchange membrane surface of the concentration chamber. Likely to happen. In other words, if the water to be treated contains a carbonate component and a hardness component, calcium ions and magnesium ions that have moved to the concentration chamber of the electric deionized water production apparatus are combined with carbonate ions etc. on the anion exchange membrane surface of the concentration chamber. However, it is easy to produce hardness scales such as calcium carbonate and magnesium carbonate.

  Patent Document 1 proposes an electric deionized water production apparatus in which an anion exchanger having a specific structure is disposed on the anion exchange membrane side of a concentration chamber. According to the apparatus of Patent Document 1, diffusion dilution of OH ions into a concentrated liquid is promoted from the surface of the porous anion exchanger, and the OH ion concentration on the surface of the porous anion exchanger can be quickly reduced. On the other hand, hardness component ions are less likely to enter the interior of the porous anion exchanger, and the opportunity for OH ions and hardness component ions to contact and react with each other is reduced, so that precipitation and accumulation of hardness components are suppressed.

However, when carbonic acid in the water to be treated (generic name for free carbonate, bicarbonate ion, carbonate ion) moves from the desalting chamber to the concentration chamber via the anion exchange membrane on the anode side (details will be described later), The anion exchanger is in the HCO ₃ form. Then, a current flows through the anion exchanger of HCO ₃ form, HCO ₃ ^- (and CO 3 ^_2-) but are attracted to the cation exchange membrane near by the electric field, can not be transmitted through the cation exchange membrane, a cation exchange It is concentrated near the membrane. Further, since hydrogen ions permeate the cation exchange membrane, the pH in the vicinity of the cation exchange membrane is lowered. Then, water and carbon dioxide (CO ₂ ) are generated, and a high-concentration carbon dioxide-containing aqueous solution layer is formed in the vicinity of the cation exchange membrane. Then, the carbon dioxide gas permeates through the cation exchange membrane 10 by diffusion and moves (back diffuses) to the desalting chamber. That is, carbon dioxide once removed from the water to be treated is dissolved again as carbon dioxide gas in the water to be treated, so-called reverse diffusion of carbonic acid occurs, and the treated water discharged from the desalting chamber is contaminated with carbonic acid components. .

In Patent Document 2, by providing a water permeable body having no strongly basic anion group between an anion exchange resin and a cation exchange membrane filled in a concentrating chamber, A deionized water production system has been proposed. According to the apparatus of Patent Document 2, it is possible to prevent the reverse diffusion of carbonic acid by preventing HCO ₃ ^{− and the} like from being blocked by the water permeable material and diffusing to the vicinity of the cation exchange membrane.

  Patent Document 3 proposes an electric deionized water production apparatus that suppresses the occurrence of reverse diffusion of carbonic acid by filling an anion exchange resin and a cation exchange resin in a concentration chamber. According to the apparatus of Patent Document 3, both the cation and the anion can move in the concentration chamber, so that the reverse diffusion of carbon dioxide can be made relatively small and the generation of scale can be reduced.

  In addition, the applicant previously stated that the macroporous pores overlap each other between the anion exchanger and the cation exchange membrane in the concentrating chamber, and the monolithic organic porous cation exchange has an open cell structure having an opening at the overlapped portion. An EDI with a body is proposed (Japanese Patent Application No. 2007-318125).

  However, in the organic porous cation exchanger described in Japanese Patent Application No. 2007-318125, the area of the skeleton part in the cross-sectional area is described as being in the range of 3 to 50% per unit cross-sectional area. For monoliths with a small pore volume of 5 ml / g or less, it is necessary to reduce the amount of water droplets in the water-in-oil emulsion, so the common opening becomes small, and the average diameter of the opening is substantially 20 μm or more. Cannot be manufactured. Further, no protrusions are observed on the surface of the skeleton forming the open cell structure of the monolith described in Japanese Patent Application No. 2007-318125. Therefore, the structure of the organic porous cation exchanger used in the present invention is different from that of the organic porous cation exchanger described in Japanese Patent Application No. 2007-318125. Details of the method for producing an organic porous cation exchanger described in Japanese Patent Application No. 2007-318125 are also disclosed in JP-A No. 2002-306976.

Japanese Patent Laid-Open No. 2001-225078 JP 2004-358440 A JP 2004-34004 A JP 2009-62512 A JP 2009-67982 A

  Accordingly, an object of the present invention is to provide an electric deionized water production apparatus and a deionized water production method capable of suppressing the occurrence of reverse diffusion of carbonic acid with a configuration different from the above and obtaining high-quality deionized water. There is to do.

The present invention provides a desalting chamber partitioned between a cathode and a cation exchange membrane on the cathode side and an anion exchange membrane on the anode side and filled with an ion exchanger, the cation exchange membrane, and the anion exchange. An electric deionized water production apparatus in which a concentration chamber provided on both sides of the demineralization chamber via a membrane and filled with an anion exchanger is disposed, the anion exchanger in the concentration chamber and the cation exchange membrane Between the organic porous body composed of a continuous skeleton phase and a continuous pore phase, a large number of particles having a diameter of 4 to 40 μm fixed to the skeleton surface of the organic porous body, or the skeleton surface of the organic porous body It is a composite structure with a large number of protrusions having a size of 4 to 40 μm formed on the surface, and has an average pore diameter of 10 to 150 μm and a total pore volume of 0.5 to 5 ml / g in a wet state. , Ion exchange capacity 0.2mg per volume under water wet condition The amount / ml or more in a monolith-shaped organic porous electrodeionization water producing apparatus characterized by disposing the cation exchanger.

Further, the present invention provides a desalting chamber partitioned between a cathode and a cation exchange membrane on the cathode side and an anion exchange membrane on the anode side and filled with an ion exchanger, the cation exchange membrane, Deionized water for producing deionized water using an electric deionized water production apparatus that is disposed on both sides of the demineralization chamber via an anion exchange membrane and is provided with a concentration chamber filled with an anion exchanger. An organic porous body composed of a continuous skeleton phase and a continuous pore phase between the anion exchanger in the concentration chamber and the cation exchange membrane, and fixed to the skeleton surface of the organic porous body A composite structure of a large number of particles having a diameter of 4 to 40 μm or a large number of protrusions having a size of 4 to 40 μm formed on the skeleton surface of the organic porous body. Average diameter 10-150 μm, total pore volume 0.5-5 ml / And providing a method for producing deionized water, characterized in that a monolithic organic porous cation exchanger having an ion exchange capacity of 0.2 mg equivalent / ml or more per volume in a wet state of water is disposed. is there.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the reverse diffusion of a carbonic acid can be suppressed and high quality deionized water can be obtained. In addition, the present invention can increase the strength of the monolithic organic porous cation exchanger.

4 is a SEM image of a monolith obtained in Reference Example 1 at a magnification of 100. FIG. 3 is a SEM image of a monolith obtained in Reference Example 1 at a magnification of 300. 3 is an SEM image of the monolith obtained in Reference Example 1 at a magnification of 3000. 2 is an EPMA image showing the distribution state of sulfur atoms on the surface of the monolith cation exchanger obtained in Reference Example 1. FIG. 2 is an EPMA image showing a distribution state of sulfur atoms in the cross-section (thickness) direction of the monolith cation exchanger obtained in Reference Example 1. FIG. 10 is a SEM image of a monolith obtained in Reference Example 2 at a magnification of 100. 6 is an SEM image of a monolith obtained in Reference Example 2 at a magnification of 600. 4 is an SEM image of the monolith obtained in Reference Example 2 at a magnification of 3000. 10 is an SEM image of a monolith obtained in Reference Example 3 at a magnification of 600. 10 is an SEM image of the monolith obtained in Reference Example 3 at a magnification of 3000. 10 is a SEM image of the monolith obtained in Reference Example 4 at a magnification of 3000. 10 is an SEM image of a monolith obtained in Reference Example 5 at a magnification of 100. 10 is a SEM image of the monolith obtained in Reference Example 5 at a magnification of 3000. It is a schematic block diagram of the electrical deionized water manufacturing apparatus which concerns on this Embodiment. It is a disassembled perspective view which shows an example of a structure of the concentration chamber which concerns on this Embodiment. It is a schematic block diagram of the electrical deionized water manufacturing apparatus which concerns on other embodiment of this invention. It is a schematic block diagram which shows the test cell for measuring the amount of carbonic acid components which moves to a desalination chamber from a concentration chamber. It is typical sectional drawing of a protrusion.

  The electric deionized water production apparatus according to the embodiment of the present invention is a deionization system in which an cation exchange membrane on one side and an anion exchange membrane on the other side are partitioned between an anode and a cathode and filled with an ion exchanger. A salt chamber and a concentration chamber provided on both sides of the desalting chamber through the cation exchange membrane and the anion exchange membrane and filled with an anion exchanger are arranged. Here, as long as the demineralization chamber of the electric deionized water production apparatus according to the present embodiment has the above configuration, for example, the cation exchange membrane and the anion A desalination chamber partitioned into two small desalination chambers by an intermediate ion exchange membrane positioned between the exchange membranes and configured to allow water to be treated to flow sequentially through the two small desalination chambers. There may be. If the desalting chamber divided into these two small desalting chambers is used, it becomes possible to efficiently perform desalting treatment of the water to be treated.

  Hereinafter, a desalting chamber partitioned into two small desalting chambers by an intermediate ion exchange membrane located between the cation exchange membrane and the anion exchange membrane will be described as an example.

  FIG. 14 is a schematic configuration diagram of an electric deionized water production apparatus according to this embodiment. In the electric deionized water production apparatus 1, the cation exchange membrane 10, the intermediate ion exchange membrane 12, and the anion exchange membrane 14 are alternately arranged apart from each other, and the intermediate ion exchange membrane 12, the anion exchange membrane 14, The first small desalination chambers d1, d3, d5 and the second small desalination chambers d2, d4, d6 partitioned by the cation exchange membrane 10 and the intermediate ion exchange membrane 12 are formed. The first small desalination chamber d1 and the second small desalination chamber d2 are the desalination chamber D1, the first small desalination chamber d3 and the second small desalination chamber d4 are the desalination chamber D2, and the first small desalination chamber d2. A desalting chamber D3 is formed by d5 and the second small desalting chamber d6. A portion formed by the anion exchange membrane 14 and the cation exchange membrane 10 located between the desalting chambers D1 and D2 and D2 and D3 is a concentration chamber 16 (16a, 16b) for flowing concentrated water. And These are sequentially arranged to form a desalting chamber D1, a concentrating chamber 16a, a desalting chamber D2, a concentrating chamber 16b, and a desalting chamber D3 from the left in FIG. Note that the numbers of the desalting chambers and the concentration chambers in FIG. Further, the concentration chamber can be provided between the desalting chamber and an electrode chamber described later, if necessary.

  The first small desalting chambers d1, d3, and d5 shown in FIG. 14 are filled with the anion exchanger 20, and the second small desalting chambers d2, d4, and d6 are mixed ions of the anion exchanger and the cation exchanger. The exchanger 18 (hereinafter also simply referred to as “mixture 18”) is filled. In addition, the ion exchangers filled in the first small desalting chambers d1, d3, d5 and the second small desalting chambers d2, d4, 6 are not limited to the above, depending on the purpose of the desalting treatment. May be selected as appropriate.

  The intermediate ion exchange membrane 12 in the above embodiment is an anion exchange membrane, but is not particularly limited.

  The concentration chambers 16 a and 16 b are filled with an anion exchanger 22. By filling the concentration chambers 16a and 16b with the anion exchanger 22, it is possible to prevent carbon dioxide from diffusing on the surface of the cation exchange membrane 10 in the concentration chambers 16a and 16b and generating a hardness scale on the surface of the cation exchange membrane 10, Further, the presence of the high conductivity anion exchanger 22 can reduce the applied voltage.

  In addition, a monolithic organic porous cation exchanger 23 is disposed between the anion exchanger 22 and the cation exchange membrane 10 in the concentration chambers 16a and 16b. In the monolithic organic porous cation exchanger 23, the flow path of the concentrating chamber is formed by the macropores and the opening, or the flow path of the concentrating chamber is formed by co-continuous pores.

  FIG. 15 is an exploded perspective view showing an example of the configuration of the concentration chamber in the present embodiment. As shown in FIG. 15, in the concentration chambers 16a and 16b, a frame 25 is disposed between the anion exchange membrane 14 in the desalting chambers D1 and D2 and the cation exchange membrane 10 in another desalting chamber D2 and D3. The hollowed out portion of the frame body 25 is filled with the anion exchanger 22. A monolithic organic porous cation exchanger 23 is disposed between the frame 25 and the cation exchange membrane 10. The frame 25 and the anion exchange membrane 14, the frame 25 and the monolithic organic porous cation exchanger 23, the monolithic organic porous cation exchanger 23 and the cation exchange membrane 10 are sealed. In the present embodiment, another frame is disposed between the frame 25 and the cation exchange membrane 10, and the monolithic organic porous cation exchanger 23 is disposed in the hollowed portion of the frame. May be. Since the ion exchange membrane is usually relatively soft, when the anion exchange membrane 14 and the frame 25 are sealed, the anion exchange membrane 14 is curved and filled into the hollowed out portion of the frame 25. The packed bed of anion exchanger 22 tends to be non-uniform. In order to prevent this, a plurality of ribs (not shown) may be provided vertically in the space of the frame body 25. Although not shown in the figure, the frame 25 is provided with an inlet and an outlet of concentrated water.

  It is preferable that the desalting chambers D1, D2, and D3 have a configuration in which the frame body is used in the same manner as described above, and an ion exchanger is filled in a hollowed portion of the frame body. That is, a frame is disposed between the cation exchange membrane 10 and the intermediate ion exchange membrane 12, and between the intermediate ion exchange membrane 12 and the anion exchange membrane 14, and the ion exchanger is filled in the hollowed portion of each frame. Is done. Further, each frame, the cation exchange membrane 10, the intermediate ion exchange membrane 12, and the anion exchange membrane 14 are sealed.

  Spaces between both outer sides of the desalting chambers D1 and D3 at both ends and both electrodes (cathode 24, anode 26) are respectively used as electrode chambers 28 and 30, and electrode water (concentrated water in this embodiment) is provided here. Water is passed. The electrode chambers 28 and 30 may be filled with a cation exchanger, an anion exchanger, or the like as necessary. In the example of FIG. 14, the anion exchanger 32 is disposed in the electrode chamber 28 and the cation exchanger 34 is disposed in the electrode chamber 30, but this is not restrictive.

  In the electric deionized water production apparatus 1 of FIG. 14, a first inflow line 36 through which water to be treated flows is connected to the inlets of the first small demineralization chambers d1, d3, d5, respectively. A first outflow line 38 for flowing out the water to be treated from the outlets of the salt chambers d1, d3, d5 is a second for flowing the water to be treated into the inlets of the second small desalting chambers d2, d4, d6. It is connected to the inflow line 40. A second outflow line 42 through which the treated water flows out is connected to the outlets of the second small desalting chambers d2, d4, and d6, respectively. With the above configuration, the water to be treated is first supplied to the first small desalting chambers d1, d3, and d5 and desalted. And the to-be-processed water which passed 1st small desalination chamber d1, d3, d5 is supplied to 2nd small desalination chamber d2, d4, d6, is further desalted, and is discharged | emitted as treated water. The flow path of the water to be treated is not limited to the above. For example, the second anion exchanger 20 filled with the anion exchanger 20 from the second small desalting chambers d2, d4, d6 filled with the mixture 18 is used. The treated water may be passed through the small desalting chambers d1, d3, and d5.

  The concentrated water inflow line 48 is connected to the inlets of the concentrating chambers 16a and 16b, respectively, and the concentrated water outflow line 50 is connected to the outlets of the concentrating chambers 16a and 16b, respectively. The electrode water inflow line is the same line as the concentrated water inflow line 48 and is connected to the inlets of the electrode chambers 28 and 30, respectively. The electrode water outflow line is the same line as the concentrated water outflow line 50, and the electrode chambers 28, 30 Each is connected to 30 outlets. In the present embodiment, the electrode water inflow line and the concentrated water inflow line 48, the electrode water outflow line and the concentrated water outflow line 50 are the same line, but may be different lines. Moreover, although the solution made to flow in as concentrated water and electrode water is made to pass through as the same thing, it is not restricted to this, It is good also considering concentrated water and electrode water as a different solution.

  Moreover, in this embodiment, the flow direction of the water to be treated flowing into the first small desalination chambers d1, d3, d5 and the flow direction of the water to be treated flowing into the second small desalination chambers d2, d4, d6. Are both descending directions, and the flow direction of the concentrated water is the opposite upward direction, but is not limited thereto.

  An example of an operation method in the case of producing deionized water by the electric deionized water production apparatus 1 in the present embodiment will be described below. First, in a state where a direct current is passed between the cathode 24 and the anode 26, water to be treated is introduced from the first inflow line 36 and concentrated water is introduced from the concentrated water inflow line 48. The water to be treated that flows from the first inflow line 36 flows through the first small desalting chambers d1, d3, and d5 and passes through the packed bed of the anion exchanger 20, so that it is carbonated (free carbonic acid, bicarbonate ions, carbonate ions). ), Anions such as silica are removed. Furthermore, the water to be treated that has passed through the first outflow line 38 of the first small desalination chambers d1, d3, d5 flows through the second inflow line 40 of the second small desalination chambers d2, d4, d6, and the mixture 18. When passing through the packed bed, cations and anions are removed, and treated water (deionized water) is obtained from the second outflow line 42. Further, the concentrated water flowing in from the concentrated water inflow line 48 flows through the concentration chambers 16a and 16b, receives ions moving through the cation exchange membrane 10 and the anion exchange membrane 14, and is used as concentrated water obtained by concentrating the ions. It flows out from the concentrated water outflow line 50. Furthermore, the electrode water flowing in from the concentrated water inflow line 48 (electrode water inflow line) flows out from the concentrated water outflow line 50 (electrode water outflow line). By the above operation, treated water (deionized water) from which impurity ions in the water to be treated have been removed is obtained.

Carbonic acid (free carbonic acid, bicarbonate ion, carbonate ion) trapped by the anion exchanger 20 in the first small desalting chambers d1, d3, d5 flowing in first is trapped by the hydroxide ion or the anion exchanger 20. It passes through the anion exchange membrane 14 on the anode side together with the other anion components thus formed, and moves to the concentration chambers 16a and 16b. The anion exchanger 22 in the concentrating chambers 16a and 16b becomes an HCO _{3 type} anion exchanger by the carbon dioxide that has moved. Unlike the present embodiment, in the state where the monolithic organic porous cation exchanger 23 is not disposed between the anion exchanger 22 and the cation exchange membrane 10 in the concentration chambers 16a and 16b, the HCO _{3 type} When an electric current flows through the anion exchanger, HCO ₃ ⁻ (and CO ₃ ²⁻ ) is attracted to the vicinity of the cation exchange membrane 10 by an electric field, but cannot pass through the cation exchange membrane 10, and in the vicinity of the cation exchange membrane 10. Concentrated. As a result, the HCO ₃ ⁻ (and CO ₃ ²⁻ ) suddenly moves between the concentration chambers 16 a and 16 b (rich side) and the first small desalting chambers d ₃ and d 5 (lean side) across the cation exchange membrane 10. A concentration gradient occurs. Further, since hydrogen ions permeate from the cation exchange membrane 10, the pH in the vicinity of the cation exchange membrane 10 in the concentration chambers 16a and 16b is lowered. Then, water and carbon dioxide (CO ₂ ) are generated, and a high-concentration carbon dioxide-containing aqueous solution layer is formed in the vicinity of the cation exchange membrane 10, and the carbon dioxide permeates through the cation exchange membrane 10 by diffusion and becomes the second small desalting. It moves (reverse diffusion) to the chambers d4 and d6. As a result, the final treated water discharged from the second small desalting chambers d4 and d6 is contaminated with carbonic acid.

  On the other hand, in the present embodiment, since the monolithic organic porous cation exchanger 23 is disposed between the anion exchanger 22 and the cation exchange membrane 10 in the concentration chambers 16a and 16b, the concentration chamber 16a. , 16 b is not in contact with the cation exchange membrane 10. Therefore, the high-concentration carbon dioxide-containing aqueous solution layer is formed on the surface or inside of the monolithic organic porous cation exchanger 23 that is separated from the cation exchange membrane 10 and mainly in contact with the anion exchanger 22. In addition, since the macropores and openings or pores of the monolithic organic porous cation exchanger 23 are channels through which concentrated water passes, the carbon dioxide gas on the surface or inside of the monolithic organic porous cation exchanger 23 is Before coming into contact with the cation exchange membrane 10, it flows out of the concentration chambers 16a and 16b together with the concentrated water. Moreover, even if carbon dioxide gas on the surface or inside of the monolithic organic porous cation exchanger 23 reaches the cation exchange membrane 10, it is diluted (lowered in concentration) in the monolithic organic porous cation exchanger 23. Therefore, the amount of carbon dioxide that permeates the cation exchange membrane 10 is greatly reduced.

  In addition, since the monolithic organic porous cation exchanger 23 of the present embodiment is dispersed with ion exchange groups (cation exchange groups), the monolithic organic porous body without ion exchange groups is concentrated in the concentration chamber 16a. The electrical resistance of the electric deionized water production apparatus 1 can be made lower than that disposed between the anion exchanger 22 and the cation exchange membrane 10 in 16b. The monolithic organic porous cation exchanger 23 has a higher filling rate than other cation exchangers such as other mesh-like materials, nonwoven fabrics, and woven fabrics. The electric resistance of the electric deionized water production apparatus 1 can be made lower than that of disposing a porous cation exchanger.

  In the configuration in which the water to be treated is contacted in the order of the anion exchanger filled in the first small desalting chamber to the mixture (anion exchanger and cation exchanger) filled in the second small desalting chamber, When the reverse diffusion phenomenon occurs, the carbonic acid moves to the second small desalting chamber of the final treatment, so that the treated water is easily contaminated with carbonic acid. However, by disposing the monolithic organic porous cation exchanger between the anion exchanger and the cation exchanger in the concentration chamber, the reverse diffusion phenomenon of carbon dioxide is suppressed. Carbon dioxide contamination can be prevented. In addition, the mixture filled in the desalting chamber can remove both anions and cations, and high-quality deionized water can be obtained.

  The monolithic organic porous cation exchanger having a composite structure is installed between the anion exchanger and the cation exchange membrane in the concentration chamber of the electric deionized water production apparatus of the present invention. In the present specification, “monolithic organic porous body” is simply referred to as “composite monolith” and “monolithic organic porous cation exchanger” or “monolithic organic porous ion exchanger” is simply referred to as “composite monolithic ion exchanger”. "Monolithic organic porous intermediate" is also simply referred to as "monolith intermediate".

<Description of composite monolith ion exchanger>
A composite monolith ion exchanger is obtained by introducing an ion exchange group into a composite monolith, and is fixed to an organic porous body composed of a continuous skeleton phase and a continuous pore phase, and the skeleton surface of the organic porous body. An organic porous body consisting of a continuous skeleton phase and a continuous pore phase, and a size formed on the skeleton surface of the organic porous body. A composite structure with a large number of protrusions having a thickness of 4 to 40 μm, and having an average pore diameter of 10 to 150 μm and a total pore volume of 0.5 to 5 ml / g in a water wet state, The ion exchange capacity per volume is 0.2 mg equivalent / ml or more, and the ion exchange groups are uniformly distributed in the composite structure. In the present specification, “particle bodies” and “projections” may be collectively referred to as “particle bodies”.

  The continuous skeleton phase and the continuous pore phase (dried body) of the organic porous body can be observed by an SEM image. Examples of the basic structure of the organic porous material include a continuous macropore structure and a co-continuous structure. The skeletal phase of the organic porous material appears as a columnar continuum, a concave wall continuum, or a composite thereof, and has a shape that is clearly different from a particle shape or a protrusion shape.

  As a preferable structure of the organic porous body, a continuous macropore structure (hereinafter referred to as “first organic porous ion”) in which bubble-shaped macropores overlap each other, and the overlapping portion becomes an opening having an average diameter of 30 to 150 μm in a wet state. And a three-dimensional continuous skeleton having an average thickness of 1 to 60 μm in a water-wet state, and three-dimensional continuous having an average diameter of 10 to 100 μm in a water-wet state between the skeletons. A co-continuous structure (hereinafter, also referred to as “second organic porous ion exchanger”).

  In the case of the first organic porous ion exchanger, the organic porous body is a continuous macropore structure in which bubble-shaped macropores are overlapped with each other, and the overlapping portions form openings (mesopores) having an average diameter of 30 to 150 μm in a wet state. It is. The average diameter of the opening of the composite monolith ion exchanger is larger than the average diameter of the opening of the composite monolith in a dry state because the entire composite monolith swells when an ion exchange group is introduced into the monolith. If the average diameter of the openings is less than 30 μm, the pressure loss of the concentrated water increases, and it may be difficult to drain the carbon dioxide gas generated in the monolith ion exchanger together with the concentrated water. Further, if the average diameter of the openings is too large, the contact between the fluid and the monolith ion exchanger becomes insufficient, and as a result, the ion exchange characteristics are deteriorated, which is not preferable.

  In the present invention, the average diameter of the openings of the dry monolith intermediate, the average diameter of the pores or openings of the dry composite monolith, and the average diameter of the holes or openings of the dry composite monolith ion exchanger are: It is a value measured by the mercury intrusion method. Further, in the organic porous ion exchanger of the present invention, the average diameter of the pores or openings of the composite monolith ion exchanger in the water wet state is the average diameter of the pores or openings of the composite monolith ion exchanger in the dry state. It is a value calculated by multiplying the swelling rate. Specifically, the diameter of the composite monolith ion exchanger in the water wet state is x1 (mm), the diameter of the composite monolith ion exchanger in the dry state obtained by drying the composite monolith ion exchanger in the water wet state. And y1 (mm), and the average diameter of the pores or openings when the dry monolithic ion exchanger is measured by mercury porosimetry is z1 (μm) The average diameter (μm) of the holes or openings of the exchanger is calculated by the following formula “average diameter of holes or openings (μm) = z1 × (x1 / y1) of the composite monolith ion exchanger in a water-wet state”. The Also, the average diameter of the pores or openings of the dry composite monolith before introduction of the ion exchange group, and the water-wetting composite monolith ion relative to the dry composite monolith when the ion exchange group is introduced into the dry composite monolith When the swelling ratio of the exchanger is known, the average diameter of the pores or openings of the composite monolith in the dry state is multiplied by the swelling ratio to calculate the average diameter of the pores of the composite monolith ion exchanger in the water wet state. You can also.

  In the case of the second organic porous body ion exchanger, the organic porous body has a three-dimensionally continuous skeleton having an average diameter of 1 to 60 μm in a water-wet state, and an average diameter between the skeletons in a water-wet state. It is a co-continuous structure having three-dimensionally continuous pores of 10 to 100 μm. When the diameter of the three-dimensionally continuous pores is less than 10 μm, the pressure loss during the permeation of the concentrate increases, making it difficult to drain the carbon dioxide generated in the monolith ion exchanger together with the concentrated water. If the thickness exceeds 100 μm, the strength may decrease, or the filling rate may decrease and the electrical resistance of the electrical deionized water production apparatus may increase.

  The average diameter of the co-continuous structure pores in the water-wet state is a value calculated by multiplying the average diameter of the pores of the composite monolith ion exchanger in the dry state measured by a known mercury intrusion method and the swelling ratio. It is. Specifically, the diameter of the composite monolith ion exchanger in the water wet state is x2 (mm), the diameter of the composite monolith ion exchanger in the dry state obtained by drying the composite monolith ion exchanger in the water wet state. Is y2 (mm), and the average diameter of the pores when the dried monolithic ion exchanger is measured by mercury porosimetry is z2 (μm), the pores of the composite monolith ion exchanger The average diameter (μm) in the water-wet state is calculated by the following formula: “Average diameter (μm) of the pores of the composite monolith ion exchanger in the water-wet state = z2 × (x2 / y2)”. In addition, the average diameter of the pores of the dry composite monolith before introduction of the ion exchange group, and the water-wet composite monolith ion exchanger with respect to the dry composite monolith when the ion exchange group is introduced into the dry composite monolith Can be calculated by multiplying the average diameter of the pores of the composite monolith in the dry state by the swelling ratio to calculate the average diameter of the pores of the composite monolith ion exchanger in the water-wet state. The average thickness of the skeleton of the co-continuous structure in the wet state is determined by performing SEM observation of the composite monolith ion exchanger in the dry state at least three times and measuring the thickness of the skeleton in the obtained image. The average value is calculated by multiplying the swelling ratio. Specifically, the diameter of the composite monolith ion exchanger in the water wet state is x3 (mm), the diameter of the composite monolith ion exchanger in the dry state obtained by drying the composite monolith ion exchanger in the water wet state. Y3 (mm), SEM observation of this dried composite monolith ion exchanger was performed at least three times, the thickness of the skeleton in the obtained image was measured, and the average value was z3 (μm). The average thickness (μm) of the skeleton of the continuous structure of the composite monolith ion exchanger in the water-wet state is expressed by the following formula: “average thickness of the skeleton of the continuous structure of the composite monolith ion exchanger in the water-wet state” (Μm) = z3 × (x3 / y3) ”. Further, the average thickness of the skeleton of the dry composite monolith before the introduction of the ion exchange groups, and the water-wet composite monolith ion exchanger with respect to the dry composite monolith when the ion exchange groups are introduced into the dry composite monolith Can be calculated by multiplying the average thickness of the skeleton of the composite monolith in the dry state by the swell ratio to the water-wet state of the skeleton of the composite monolith ion exchanger. The skeleton forming the co-continuous structure is rod-shaped and has a circular cross-sectional shape, but may have a cross-section with different diameters such as an elliptical cross-sectional shape. The thickness in this case is the average of the minor axis and the major axis.

  Further, if the average diameter of the three-dimensionally continuous skeleton is less than 1 μm, it is not preferable because the ion exchange capacity per volume decreases, and if it exceeds 60 μm, the uniformity of ion exchange characteristics is lost. Absent.

  A preferable value of the average diameter of the pores of the composite monolith ion exchanger in a wet state with water is 10 to 120 μm. When the organic porous body constituting the composite monolith ion exchanger is the first organic porous body, the preferred pore diameter of the composite monolith ion exchanger is 30 to 120 μm, and the organic porous body constituting the composite monolith ion exchanger In the case of the second organic porous body, a preferable value of the pore diameter of the composite monolith ion exchanger is 10 to 90 μm.

  In the composite monolith ion exchanger according to the present invention, the diameter of the particles and the size of the protrusions in a wet state are 4 to 40 μm, preferably 4 to 30 μm, and particularly preferably 4 to 20 μm. In the present invention, both the particles and the protrusions are observed as protrusions on the surface of the skeleton, and the particles observed are referred to as particles, and the protrusions that are not granular are protrusions. Called the body. FIG. 18 shows a schematic cross-sectional view of the protrusion. As shown to (A)-(E) in FIG. 18, the protrusion-shaped thing protruded from the skeleton surface 61 is the protrusion 62, and the protrusion 62 is like the protrusion 62a shown to (A). The shape close to a granular shape, a hemispherical shape like a projection 62b shown in (B), and a swell of the skeleton surface like a projection 62c shown in (C). In addition, the protrusion 61 has a shape that is longer in the direction perpendicular to the skeleton surface 61 than in the plane direction of the skeleton surface 61, like the protrusion 62d shown in FIG. There is a thing of the shape which protruded in the several direction like the protrusion 62e shown to (E). Further, the size of the protrusions is determined by the SEM image when observed by SEM, and indicates the length of the portion where the width of each protrusion is the largest in the SEM image.

  In the composite monolith ion exchanger according to the present invention, the proportion of 4 to 40 μm particles in a wet state in water is 70% or more, preferably 80% or more. In addition, the ratio which 4-40 micrometers particle bodies etc. occupy in the water wet state in all the particle bodies etc. points out the number ratio of 4-40 micrometers particle bodies etc. in the water wet state which occupy the number of all particle bodies. Further, the surface of the skeletal phase is covered by 40% or more, preferably 50% or more by the whole particles. The coverage ratio of the surface of the skeleton layer with particles or the like refers to the area ratio on the SEM image when the surface is observed by SEM, that is, the area ratio when the surface is viewed in plan. If the size of the particle covering the wall surface or the skeleton deviates from the above range, the effect of improving the contact efficiency between the fluid and the skeleton surface of the composite monolith ion exchanger and the inside of the skeleton is not preferable. In addition, all the particulate bodies etc. are all the particulate bodies formed on the surface of the skeleton layer including all the particulate bodies and protrusions in the size range other than the 4-40 μm particulate bodies in the wet state. And a protrusion.

  The diameter or size of the particles attached to the surface of the skeleton of the composite monolith ion exchanger in the water-wet state is the diameter or size of the particles obtained by observing the SEM image of the composite monolith ion exchanger in the dry state. Further, the value calculated by multiplying the swelling rate when the dry state is changed to the wet state, or the diameter or size of the particulates obtained by observing the SEM image of the composite monolith in the dry state before introducing the ion exchange group And a value calculated by multiplying the swelling ratio before and after introduction of the ion exchange group. Specifically, the diameter of the composite monolith ion exchanger in the water wet state is x4 (mm), the diameter of the composite monolith ion exchanger in the dry state obtained by drying the composite monolith ion exchanger in the water wet state. Is y4 (mm), and the diameter or size of the particles in the SEM image of the dried composite monolith ion exchanger observed by SEM is z4 (μm). The diameter or size (μm) of the particles of the monolith ion exchanger is expressed by the following formula: “diameter or size (μm) of the particles of the composite monolith ion exchanger in a water-wet state” = z4 × (x4 / y4) Is calculated. Then, the diameter or size of all particles observed in the SEM image of the composite monolith ion exchanger in the dry state is measured, and based on the value, all particles in one field of view SEM image, etc. The diameter or size of the water in a wet state is calculated. The SEM observation of the dried composite monolith ion exchanger is performed at least three times, and the diameter or size of the whole particle in the SEM image in the water-wet state is calculated in all fields of view. It is confirmed whether or not a particle body or the like at 4 to 40 μm is observed, and when it is confirmed in the entire visual field, the diameter or size is 4 to 40 μm in a wet state on the skeleton surface of the composite monolith ion exchanger. It is determined that the particle body at is formed. Further, according to the above, the diameter or size in the water wet state of all particles in the SEM image is calculated for each visual field, and the particle size of 4 to 40 μm in the water wet state occupying in the whole particles for each visual field. When the proportion of the particles, etc. is 40% or more in the wet state in all the particles in the entire visual field, the skeleton surface of the composite monolith ion exchanger is obtained. It is determined that the proportion of 4 to 40 μm particles in the wet state is 70% or more in all particles formed in the above. Further, according to the above, the coverage ratio of the surface of the skeletal layer with all particles in the SEM image was determined for each field of view, and the coverage ratio of the surface of the skeleton layer with all particles in all fields was 40% or more. In this case, it is determined that the ratio of the surface of the skeleton layer of the composite monolith ion exchanger covered with all the particulates is 40% or more. In addition, the diameter or size of the particles of the composite monolith in the dry state before the introduction of the ion exchange group and the composite monolith ion exchange in the wet state with respect to the dry composite monolith when the ion exchange group is introduced into the monolith in the dry state If the swelling rate of the body is known, the diameter or size of the particles of the composite monolith in the dry state is multiplied by the swelling rate to obtain the diameter or size of the particles of the composite monolith ion exchanger in the water wet state. In the same manner as described above, the diameter or size of the particles of the composite monolith ion exchanger in the water wet state, the ratio of the particles of 4 to 40 μm in the water wet state, etc. in the total particles, etc. In addition, the coverage ratio of the surface of the skeleton layer with particle bodies can be obtained.

  When the coverage of the skeletal phase surface with particles and the like is less than 40%, the effect of improving the contact efficiency between the fluid and the inside of the skeleton of the composite monolith ion exchanger and the skeleton surface is reduced, and the uniformity of the ion exchange behavior is reduced. Since it will be damaged, it is not preferable. Examples of the method for measuring the coverage with the particulates include an image analysis method using a monolith (dry body) SEM image.

  The total pore volume of the composite monolith ion exchanger is the same as the total pore volume of the composite monolith. That is, even when the ion exchange group is introduced into the composite monolith to swell and increase the opening diameter, the total pore volume hardly changes because the skeletal phase is thick. If the total pore volume is less than 0.5 ml / g, the pressure loss of the concentrated water flowing in the monolith increases, and it may be difficult to drain the carbon dioxide gas generated in the monolith ion exchanger together with the concentrated water. is there. On the other hand, if the total pore volume exceeds 5 ml / g, the strength of the monolith ion exchanger is reduced and the electrical resistance of the electric deionized water production apparatus is increased, which is not preferable. Note that the total pore volume of the composite monolith (monolith intermediate, composite monolith, composite monolith ion exchanger) is the same both in the dry state and in the water wet state.

  Note that the pressure loss when water is permeated through the composite monolith ion exchanger is the same as the pressure loss when water is permeated through the composite monolith.

  The composite monolith ion exchanger of the present invention has an ion exchange capacity of 0.2 mg equivalent / ml or more, preferably 0.3 to 1.8 mg equivalent / ml per volume in a water-wet state. If the cation exchange capacity per volume is less than 0.2 mg equivalent / ml, the conductivity decreases and the electrical resistance increases, which is not preferable. In addition, the ion exchange capacity per weight in the dry state of the composite monolith ion exchanger of the present invention is not particularly limited, but since the ion exchange groups are uniformly introduced to the skeleton surface and the skeleton inside the composite monolith, 5 mg equivalent / g. The ion exchange capacity of the organic porous material in which the ion exchange group is introduced only on the surface of the skeleton cannot be determined depending on the kind of the organic porous material or the ion exchange group, but is 500 μg equivalent / g at most.

  Examples of the ion exchange group introduced into the composite monolith of the present invention include cation exchange groups such as a sulfonic acid group, a carboxylic acid group, an iminodiacetic acid group, a phosphoric acid group, and a phosphoric acid ester group.

  In the composite monolith ion exchanger of the present invention, the introduced ion exchange groups are uniformly distributed not only on the surface of the skeleton of the composite monolith but also inside the skeleton phase. Here, “the ion exchange groups are uniformly distributed” means that the distribution of the ion exchange groups is uniformly distributed at least on the order of μm on the surface of the skeleton phase and inside the skeleton phase. The distribution of ion exchange groups can be confirmed relatively easily by using EPMA or the like. In addition, when the ion exchange groups are uniformly distributed not only on the surface of the composite monolith but also inside the skeleton phase, the physical and chemical properties of the surface and the interior can be made uniform, so that the swelling and shrinkage can be prevented. Durability is improved.

  The composite monolith ion exchanger of the present invention has a thickness of 1 mm or more, and is distinguished from a membrane-like porous body. When the thickness is less than 1 mm, the ion exchange capacity per porous body is extremely reduced, which is not preferable. The thickness of the composite monolith ion exchanger is preferably 3 mm to 1000 mm. In addition, the composite monolith ion exchanger of the present invention has high mechanical strength because the basic structure of the skeleton is a continuous pore structure.

The composite monolith ion exchanger of the present invention is obtained by stirring a mixture of an oil-soluble monomer containing no ion exchange group, a first crosslinking agent having at least two or more vinyl groups in one molecule, a surfactant and water. Preparing a water-in-oil emulsion and then polymerizing the water-in-oil emulsion to obtain a monolithic organic porous intermediate having a continuous macropore structure with a total pore volume of 5 to 30 ml / g, vinyl monomer, A mixture comprising a second crosslinking agent having at least two vinyl groups in one molecule, an organic solvent that dissolves the vinyl monomer or the second crosslinking agent but does not dissolve the polymer formed by polymerization of the vinyl monomer, and a polymerization initiator. Step II for preparing the compound II. The mixture obtained in Step II is allowed to stand, and polymerization is performed in the presence of the monolithic organic porous intermediate obtained in Step I II When the monolithic organic porous material is produced by performing the IV step of introducing an ion exchange group into the monolithic organic porous material obtained in the steps I and III, the following (1) to (5):
(1) The polymerization temperature in step III is at least 5 ° C. lower than the 10-hour half-life temperature of the polymerization initiator;
(2) The mol% of the second cross-linking agent used in step II is at least twice the mol% of the first cross-linking agent used in step I;
(3) The vinyl monomer used in Step II is a vinyl monomer having a structure different from that of the oil-soluble monomer used in Step I;
(4) The organic solvent used in step II is a polyether having a molecular weight of 200 or more;
(5) The concentration of the vinyl monomer used in Step II is 30% by weight or less in the mixture of Step II; obtained by performing Step II or Step III under conditions that satisfy at least one of the conditions .

(Method for producing monolith intermediate)
In the method for producing a monolith according to the present invention, in the step I, an oil-soluble monomer not containing an ion exchange group, a first crosslinking agent having at least two or more vinyl groups in one molecule, a mixture of a surfactant and water are stirred. In this step, a water-in-oil emulsion is prepared, and then the water-in-oil emulsion is polymerized to obtain a monolith intermediate having a continuous macropore structure having a total pore volume of 5 to 30 ml / g. The step I for obtaining the monolith intermediate may be performed according to the method described in JP-A-2002-306976.

  Examples of the oil-soluble monomer that does not contain an ion exchange group include an oleophilic monomer that does not contain an ion exchange group such as a carboxylic acid group, a sulfonic acid group, and a quaternary ammonium group, has low solubility in water. Preferable examples of these monomers include styrene, α-methylstyrene, vinyl toluene, vinyl benzyl chloride, divinyl benzene, ethylene, propylene, isobutene, butadiene, ethylene glycol dimethacrylate, and the like. These monomers can be used alone or in combination of two or more.

  Examples of the first crosslinking agent having at least two or more vinyl groups in one molecule include divinylbenzene, divinylnaphthalene, divinylbiphenyl, and ethylene glycol dimethacrylate. These crosslinking agents can be used singly or in combination of two or more. A preferred first cross-linking agent is an aromatic polyvinyl compound such as divinylbenzene, divinylnaphthalene, and divinylbiphenyl because of its high mechanical strength. The amount of the first crosslinking agent used is 0.3 to 10 mol%, particularly 0.3 to 5 mol%, and more preferably 0.3 to 3 mol%, based on the total amount of the vinyl monomer and the first crosslinking agent. Is preferred. If the amount of the first crosslinking agent used is less than 0.3 mol%, the mechanical strength of the monolith is insufficient, which is not preferable. On the other hand, if it exceeds 10 mol%, the monolith becomes more brittle and the flexibility is lost, and the amount of ion exchange groups introduced decreases, which is not preferable.

  The surfactant is not particularly limited as long as it can form a water-in-oil (W / O) emulsion when an oil-soluble monomer containing no ion exchange group and water are mixed, and sorbitan monooleate, Nonionic surfactants such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan trioleate, polyoxyethylene nonylphenyl ether, polyoxyethylene stearyl ether, polyoxyethylene sorbitan monooleate; potassium oleate Anionic surfactants such as sodium dodecylbenzenesulfonate and dioctyl sodium sulfosuccinate; cationic surfactants such as distearyldimethylammonium chloride; amphoteric surfactants such as lauryldimethylbetaine can be used . These surfactants can be used alone or in combination of two or more. The water-in-oil emulsion refers to an emulsion in which an oil phase is a continuous phase and water droplets are dispersed therein. The amount of the surfactant added may vary depending on the type of oil-soluble monomer and the size of the target emulsion particles (macropores), but it cannot be generally stated, but the total amount of oil-soluble monomer and surfactant Can be selected within a range of about 2 to 70%.

  In Step I, a polymerization initiator may be used as necessary when forming a water-in-oil emulsion. As the polymerization initiator, a compound that generates radicals by heat and light irradiation is preferably used. The polymerization initiator may be water-soluble or oil-soluble. For example, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2 , 2′-azobis (2-methylbutyronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2′-azobisisobutyrate, 4,4′-azobis ( 4-cyanovaleric acid), 1,1'-azobis (cyclohexane-1-carbonitrile), benzoyl peroxide, lauroyl peroxide, potassium persulfate, ammonium persulfate, hydrogen peroxide-ferrous chloride, sodium persulfate- Examples include acidic sodium sulfite.

  There is no particular limitation on the mixing method when mixing the oil-soluble monomer containing no ion exchange group, the first cross-linking agent, the surfactant, water and the polymerization initiator to form a water-in-oil emulsion, A method of mixing components all at once, an oil-soluble monomer, a first crosslinking agent, a surfactant, an oil-soluble component that is an oil-soluble polymerization initiator, and a water-soluble component that is water or a water-soluble polymerization initiator For example, a method in which each component is mixed after being uniformly dissolved separately can be used. There is no particular limitation on the mixing apparatus for forming the emulsion, and a normal mixer, homogenizer, high-pressure homogenizer, or the like can be used, and an appropriate apparatus may be selected to obtain the desired emulsion particle size. Moreover, there is no restriction | limiting in particular about mixing conditions, The stirring rotation speed and stirring time which can obtain the target emulsion particle size can be set arbitrarily.

  The monolith intermediate obtained in Step I has a continuous macropore structure. When this coexists in the polymerization system, particles or the like are formed on the surface of the skeleton phase of the continuous macropore structure using the structure of the monolith intermediate as a template, or particles or the like are formed on the surface of the skeleton phase of the co-continuous structure. Or The monolith intermediate is an organic polymer material having a crosslinked structure. Although the crosslinking density of the polymer material is not particularly limited, it contains 0.3 to 10 mol%, preferably 0.3 to 5 mol% of crosslinked structural units with respect to all the structural units constituting the polymer material. Is preferred. When the cross-linking structural unit is less than 0.3 mol%, the mechanical strength is insufficient, which is not preferable. On the other hand, if it exceeds 10 mol%, the porous body becomes brittle and the flexibility is lost, which is not preferable.

  The total pore volume of the monolith intermediate is 5-30 ml / g, preferably 6-28 ml / g. If the total pore volume is too small, the total pore volume of the monolith obtained after polymerizing the vinyl monomer becomes too small, and the pressure loss during fluid permeation increases, which is not preferable. On the other hand, if the total pore volume is too large, the structure of the monolith obtained after polymerizing the vinyl monomer tends to be non-uniform, and in some cases, the structure collapses, which is not preferable. In order to set the total pore volume of the monolith intermediate in the above numerical range, the ratio (weight) of the monomer to water may be set to approximately 1: 5 to 1:35.

  When the ratio of this monomer to water is approximately 1: 5 to 1:20, a monolith intermediate having a total pore volume of 5 to 16 ml / g and a continuous macropore structure can be obtained and obtained through Step III. The obtained composite monolithic organic porous body is the first organic porous body. Further, if the blending ratio is approximately 1:20 to 1:35, a monolith intermediate having a total pore volume of more than 16 ml / g and a continuous macropore structure of 30 ml / g or less can be obtained. The organic porous body of the composite monolith obtained through the above is obtained as the second organic porous body.

  Moreover, the average diameter of the opening (mesopore) which is an overlap part of a macropore and a macropore is 20-100 micrometers in a dry state in a monolith intermediate. When the average diameter of the openings is less than 20 μm, the opening diameter of the monolith obtained after polymerizing the vinyl monomer becomes small, and the pressure loss at the time of passing water becomes large, which is not preferable. On the other hand, if it exceeds 100 μm, the opening diameter of the monolith obtained after polymerizing the vinyl monomer becomes too large, and it becomes difficult to form a water flow path uniformly. Monolith intermediates preferably have a uniform structure with uniform macropore size and aperture diameter, but are not limited to this, and the uniform structure is dotted with nonuniform macropores larger than the size of the uniform macropore. You may do.

(Production method of composite monolith)
Step II is an organic solvent in which a vinyl monomer, a second cross-linking agent having at least two vinyl groups in one molecule, a vinyl monomer or a second cross-linking agent dissolves, but a polymer formed by polymerization of the vinyl monomer does not dissolve. And a step of preparing a mixture comprising a polymerization initiator. In addition, there is no order of I process and II process, II process may be performed after I process, and I process may be performed after II process.

  The vinyl monomer used in step II is not particularly limited as long as it is a lipophilic vinyl monomer that contains a polymerizable vinyl group in the molecule and has high solubility in an organic solvent. Specific examples of these vinyl monomers include aromatic vinyl monomers such as styrene, α-methylstyrene, vinyl toluene, vinyl benzyl chloride, vinyl biphenyl and vinyl naphthalene; α-olefins such as ethylene, propylene, 1-butene and isobutene; Diene monomers such as butadiene, isoprene and chloroprene; halogenated olefins such as vinyl chloride, vinyl bromide, vinylidene chloride and tetrafluoroethylene; nitrile monomers such as acrylonitrile and methacrylonitrile; vinyl such as vinyl acetate and vinyl propionate Esters: methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-methacrylic acid 2- Hexyl, cyclohexyl methacrylate, benzyl methacrylate, and (meth) acrylic monomer of glycidyl methacrylate. These monomers can be used alone or in combination of two or more. The vinyl monomer suitably used in the present invention is an aromatic vinyl monomer such as styrene or vinyl benzyl chloride.

  The added amount of these vinyl monomers is 3 to 40 times, preferably 4 to 30 times, by weight with respect to the monolith intermediate coexisting during polymerization. If the amount of vinyl monomer added is less than 3 times that of the porous body, it is preferable because the particles cannot be formed in the skeleton of the produced monolith, and the ion exchange capacity per volume after introduction of the ion exchange groups is reduced. Absent. On the other hand, if the amount of vinyl monomer added exceeds 40 times, the opening diameter becomes small and the pressure loss during fluid permeation increases, which is not preferable.

  As the second crosslinking agent used in Step II, one having at least two polymerizable vinyl groups in the molecule and having high solubility in an organic solvent is preferably used. Specific examples of the second crosslinking agent include divinylbenzene, divinylnaphthalene, divinylbiphenyl, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, butanediol diacrylate, and the like. These 2nd crosslinking agents can be used individually by 1 type or in combination of 2 or more types. A preferred second crosslinking agent is an aromatic polyvinyl compound such as divinylbenzene, divinylnaphthalene, and divinylbiphenyl because of its high mechanical strength and stability to hydrolysis. The amount of the second crosslinking agent used is preferably 0.3 to 20 mol%, particularly 0.3 to 10 mol%, based on the total amount of the vinyl monomer and the second crosslinking agent. When the amount of the crosslinking agent used is less than 0.3 mol%, the mechanical strength of the monolith is insufficient, which is not preferable. On the other hand, if it exceeds 20 mol%, the monolith becomes more brittle and the flexibility is lost, and the amount of ion exchange groups introduced decreases, which is not preferable.

  The organic solvent used in step II is an organic solvent that dissolves the vinyl monomer and the second cross-linking agent but does not dissolve the polymer formed by polymerization of the vinyl monomer, in other words, a poor solvent for the polymer formed by polymerization of the vinyl monomer. It is. Since the organic solvent varies greatly depending on the type of vinyl monomer, it is difficult to list general specific examples. For example, when the vinyl monomer is styrene, the organic solvent includes methanol, ethanol, propanol, butanol, Alcohols such as hexanol, cyclohexanol, octanol, 2-ethylhexanol, decanol, dodecanol, propylene glycol, tetramethylene glycol; chain (poly) ethers such as diethyl ether, butyl cellosolve, polyethylene glycol, polypropylene glycol, polytetramethylene glycol Chain saturated hydrocarbons such as hexane, heptane, octane, isooctane, decane, dodecane, etc .; Ethyl acetate, isopropyl acetate, cellosolve acetate, ethyl propionate, etc. Ethers, and the like. Moreover, even if it is a good solvent of polystyrene like a dioxane, THF, and toluene, when it is used with the said poor solvent and the usage-amount is small, it can be used as an organic solvent. These organic solvents are preferably used so that the concentration of the vinyl monomer is 5 to 80% by weight. If the amount of the organic solvent used deviates from the above range and the vinyl monomer concentration is less than 5% by weight, the polymerization rate is lowered, which is not preferable. On the other hand, if the vinyl monomer concentration exceeds 80% by weight, the polymerization may run away, which is not preferable.

  As the polymerization initiator, a compound that generates radicals by heat and light irradiation is preferably used. The polymerization initiator is preferably oil-soluble. Specific examples of the polymerization initiator used in the present invention include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis ( 2-methylbutyronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2′-azobisisobutyrate, 4,4′-azobis (4-cyanovaleric acid) 1,1′-azobis (cyclohexane-1-carbonitrile), benzoyl peroxide, lauroyl peroxide, tetramethylthiuram disulfide and the like. The amount of polymerization initiator used varies greatly depending on the type of monomer, polymerization temperature, etc., but can be used in a range of about 0.01 to 5% with respect to the total amount of vinyl monomer and second crosslinking agent. .

  In step III, the mixture obtained in step II is allowed to stand, and in the presence of the monolith intermediate obtained in step I, polymerization is performed to obtain a composite monolith. The monolith intermediate used in the step III plays a very important role in creating the monolith having the novel structure of the present invention. As disclosed in JP-A-7-501140 and the like, when a vinyl monomer and a second cross-linking agent are allowed to stand in a specific organic solvent in the absence of a monolith intermediate, a particle aggregation type monolithic organic material is obtained. A porous body is obtained. On the other hand, when a monolith intermediate having a continuous macropore structure is present in the polymerization system as in the present invention, the structure of the monolith after polymerization changes dramatically, the particle aggregation structure disappears, and the specific skeleton described above is lost. A monolith having a structure is obtained.

  The internal volume of the reaction vessel is not particularly limited as long as it is large enough to allow the monolith intermediate to exist in the reaction vessel. When the monolith intermediate is placed in the reaction vessel, there is a gap around the monolith in plan view. Or a monolith intermediate in the reaction vessel with no gap. Of these, the monolith after polymerization does not receive any pressure from the inner wall of the vessel and enters the reaction vessel without any gap, so that the monolith is not distorted and the reaction raw materials are not wasted and efficient. Even when the internal volume of the reaction vessel is large and there are gaps around the monolith after polymerization, the vinyl monomer and the crosslinking agent are adsorbed and distributed on the monolith intermediate, so the gaps in the reaction vessel A particle aggregate structure is not generated in the portion.

  In step III, the monolith intermediate is placed in a reaction vessel impregnated with the mixture (solution). As described above, the blending ratio of the mixture obtained in Step II and the monolith intermediate is 3 to 40 times by weight, preferably 4 to 30 times by weight, relative to the monolith intermediate. It is suitable to mix. Thereby, it is possible to obtain a monolith having a specific skeleton while having an appropriate opening diameter. In the reaction vessel, the vinyl monomer and the crosslinking agent in the mixture are adsorbed and distributed on the skeleton of the monolith intermediate that has been allowed to stand, and polymerization proceeds in the skeleton of the monolith intermediate.

  Various polymerization conditions can be selected depending on the type of monomer and the type of initiator. For example, when 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide, or the like is used as an initiator, an inert atmosphere What is necessary is just to heat-polymerize at 20-100 degreeC for 1 to 48 hours in the lower sealed container. By heat polymerization, the vinyl monomer adsorbed and distributed on the skeleton of the monolith intermediate and the crosslinking agent are polymerized in the skeleton to form the specific skeleton structure. After completion of the polymerization, the content is taken out and extracted with a solvent such as acetone for the purpose of removing unreacted vinyl monomer and organic solvent to obtain a monolith having a specific skeleton structure.

  When the above-mentioned composite monolith is produced, the skeleton, which is the characteristic structure of the present invention, is obtained by performing the II step or the III step under the conditions satisfying at least one of the following conditions (1) to (5). A composite monolith having particles or the like formed on the surface can be produced.

(1) The polymerization temperature in step III is a temperature that is at least 5 ° C. lower than the 10-hour half-life temperature of the polymerization initiator.
(2) The mol% of the second cross-linking agent used in step II is at least twice the mol% of the first cross-linking agent used in step I.
(3) The vinyl monomer used in step II is a vinyl monomer having a structure different from that of the oil-soluble monomer used in step I.
(4) The organic solvent used in step II is a polyether having a molecular weight of 200 or more.
(5) The concentration of the vinyl monomer used in Step II is 30% by weight or less in the mixture of Step II.

(Description of (1) above)
The 10-hour half temperature is a characteristic value of the polymerization initiator, and if the polymerization initiator to be used is determined, the 10-hour half temperature can be known. Moreover, if there exists desired 10-hour half temperature, the polymerization initiator applicable to it can be selected. In step III, the polymerization rate is lowered by lowering the polymerization temperature, and particles and the like can be formed on the surface of the skeleton phase. The reason for this is that the monomer concentration drop inside the skeleton phase of the monolith intermediate becomes gradual, and the monomer distribution rate from the liquid phase part to the monolith intermediate decreases, so the surplus monomer is on the surface of the skeleton layer of the monolith intermediate. It is thought that it was concentrated in the vicinity and polymerized in situ.

  The preferred polymerization temperature is a temperature that is at least 10 ° C. lower than the 10-hour half-life temperature of the polymerization initiator used. Although the lower limit of the polymerization temperature is not particularly limited, the polymerization rate decreases as the temperature decreases, and the polymerization time becomes unacceptably long. Therefore, the polymerization temperature is 5 to 20 ° C. with respect to the 10-hour half temperature. It is preferable to set to a low range.

(Description of (2))
When the mol% of the second cross-linking agent used in Step II is set to be twice or more of the mol% of the first cross-linking agent used in Step I, the composite monolith of the present invention is obtained. The reason for this is that the compatibility between the monolith intermediate and the polymer produced by impregnation polymerization is reduced and phase separation proceeds, so the polymer produced by impregnation polymerization is excluded in the vicinity of the surface of the skeleton phase of the monolith intermediate, It is considered that irregularities such as particles are formed on the surface. In addition, mol% of a crosslinking agent is a crosslinking density mol%, Comprising: The amount of crosslinking agents (mol%) with respect to the total amount of a vinyl monomer and a crosslinking agent is said.

  The upper limit of the second crosslinker mol% used in step II is not particularly limited, but if the second crosslinker mol% is extremely large, cracks occur in the monolith after polymerization, and the brittleness of the monolith proceeds and flexibility is increased. This is not preferable because it causes a problem that the amount of ion exchange groups to be lost is reduced. A preferred multiple of the second crosslinking agent mol% is 2 to 10 times. On the other hand, even when the mol% of the first cross-linking agent used in step I is set to be twice or more the mol% of the second cross-linking agent used in step II, the formation of particles on the surface of the skeleton phase does not occur. The composite monolith of the present invention cannot be obtained.

(Explanation of (3))
When the vinyl monomer used in Step II is a vinyl monomer having a structure different from that of the oil-soluble monomer used in Step I, the composite monolith of the present invention is obtained. For example, if the structures of vinyl monomers are slightly different, such as styrene and vinyl benzyl chloride, a composite monolith having particles or the like formed on the surface of the skeleton phase is generated. In general, two types of homopolymers obtained from two types of monomers that are slightly different in structure are not compatible with each other. Therefore, a monomer having a structure different from that of the monomer used for forming the monolith intermediate used in Step I, that is, a monomer other than the monomer used for forming the monolith intermediate used in Step I is used in Step II to polymerize in Step III. The monomer used in Step II is uniformly distributed and impregnated into the monolith intermediate, but when the polymerization proceeds and the polymer is produced, the produced polymer is not compatible with the monolith intermediate. Separation proceeds, and the produced polymer is considered to be excluded in the vicinity of the surface of the skeleton phase of the monolith intermediate, and irregularities such as particles are formed on the surface of the skeleton phase.

(Explanation of (4))
When the organic solvent used in step II is a polyether having a molecular weight of 200 or more, the composite monolith of the present invention is obtained. Polyethers have a relatively high affinity with monolith intermediates, especially low molecular weight cyclic polyethers are good solvents for polystyrene, and low molecular weight chain polyethers are not good solvents but have considerable affinity. . However, as the molecular weight of the polyether increases, the affinity with the monolith intermediate dramatically decreases and shows little affinity with the monolith intermediate. When such a solvent having poor affinity is used as the organic solvent, diffusion of the monomer into the skeleton of the monolith intermediate is inhibited, and as a result, the monomer is polymerized only near the surface of the skeleton of the monolith intermediate. It is considered that particles and the like are formed on the phase surface and irregularities are formed on the skeleton surface.

  The upper limit of the molecular weight of the polyether is not particularly limited as long as it is 200 or more. However, when the molecular weight is too high, the viscosity of the mixture prepared in the step II becomes high, and it is difficult to impregnate the monolith intermediate. Therefore, it is not preferable. The molecular weight of the preferred polyether is 200 to 100,000, particularly preferably 200 to 10,000. The terminal structure of the polyether may be an unmodified hydroxyl group, etherified with an alkyl group such as a methyl group or an ethyl group, or esterified with acetic acid, oleic acid, lauric acid, stearic acid, or the like. It may be made.

(Explanation of (5))
When the concentration of the vinyl monomer used in Step II is 30% by weight or less in the mixture in Step II, the composite monolith of the present invention is obtained. By reducing the monomer concentration in the step II, the polymerization rate is reduced, and for the same reason as the above (1), particles and the like can be formed on the surface of the skeleton phase, and irregularities can be formed on the surface of the skeleton phase. . Although the lower limit of the monomer concentration is not particularly limited, the polymerization rate decreases as the monomer concentration decreases and the polymerization time becomes unacceptably long, so the monomer concentration may be set to 10 to 30% by weight. preferable.

  The composite monolith obtained in the step III includes an organic porous body composed of a continuous skeleton phase and a continuous pore phase, a large number of particles fixed to the skeleton surface of the organic porous body, or a skeleton surface of the organic porous body. It is a composite structure with a number of protrusions formed on it. The continuous skeleton phase and the continuous pore phase of the organic porous body can be observed by SEM images. The basic structure of the organic porous body is a continuous macropore structure or a co-continuous structure.

  The continuous macropore structure in the composite monolith is such that bubble-shaped macropores overlap each other, and the overlapping portion becomes an opening having an average diameter of 20 to 100 μm in a dry state. The bicontinuous structure in the composite monolith has an average thickness. Is composed of a three-dimensionally continuous skeleton of 0.8 to 40 μm in a dry state and three-dimensionally continuous pores having an average diameter of 8 to 80 μm by drying between the skeletons.

  Step IV is a step of introducing an ion exchange group into the composite monolith obtained in step III. According to this introduction method, the porous structure of the obtained composite monolith ion exchanger can be strictly controlled.

  The method for introducing an ion exchange group into the composite monolith is not particularly limited, and a known method such as polymer reaction or graft polymerization can be used. For example, as a method of introducing a sulfonic acid group, if the composite monolith is a styrene-divinylbenzene copolymer, etc., a method of sulfonation using chlorosulfuric acid, concentrated sulfuric acid, or fuming sulfuric acid; radical initiating groups uniformly on the composite monolith And a method of grafting sodium styrene sulfonate or acrylamido-2-methylpropane sulfonic acid by introducing a chain transfer group into the skeleton surface or inside the skeleton; Similarly, after graft polymerization of glycidyl methacrylate, the sulfonic acid group is converted by functional group conversion. The method etc. which introduce | transduce are mentioned. Among these methods for introducing sulfonic acid groups, the method of introducing sulfonic acid groups into a styrene-divinylbenzene copolymer using chlorosulfuric acid is preferable because ion exchange groups can be introduced uniformly and quantitatively. Examples of ion exchange groups to be introduced include cation exchange groups such as carboxylic acid groups, iminodiacetic acid groups, sulfonic acid groups, phosphoric acid groups, and phosphoric acid ester groups.

  In the said electrical deionized water manufacturing apparatus, the structure which makes the to-be-processed water contact from the anion exchanger 20 with which the 1st small demineralization chamber d1, d3, d5 was filled is illustrated. In the present embodiment, the water flow order of the ion exchanger filled in the desalting chamber and the ion exchanger filled in the desalting chamber are not particularly limited, but the first small desalting is described below. An electric deionized water production apparatus will be described in which the chamber is filled with a cation exchanger, the second small desalting chamber is filled with an anion exchanger, and the water to be treated is contacted in the order of the cation exchanger to the anion exchanger.

  FIG. 16 is a schematic configuration diagram of an electrical deionized water production apparatus according to another embodiment of the present invention. The first small desalting chambers d1, d3, d5 shown in FIG. 16 are partitioned by the cation exchange membrane 10 and the intermediate ion exchange membrane 12, and the second small desalting chambers d2, d4, d6 are separated by the intermediate ion exchange membrane 12. And an anion exchange membrane 14. Further, the first small desalting chambers d1, d3, d5 shown in FIG. 16 are filled with a cation exchanger 46, and the second small desalting chambers d2, d4, d6 are filled with an anion exchanger 20. Yes. In the present embodiment, the intermediate ion exchange membrane 12 is an anion exchange membrane, but is not limited to an anion exchange membrane. Moreover, since the concentration chambers 16a and 16b and the electrode chambers 28 and 30 have the same configuration as that of the electrical deionized water production apparatus 1 in FIG.

  In the electric deionized water production apparatus 2 of FIG. 16, the first inflow line 36 through which the water to be treated flows is connected to the inlets of the first small demineralization chambers d1, d3, d5, respectively. A first outflow line 38 for flowing out the water to be treated from the outlets of the salt chambers d1, d3, d5 is a second for flowing the water to be treated into the inlets of the second small desalting chambers d2, d4, d6. It is connected to the inflow line 40. A second outflow line 42 through which the treated water flows out is connected to the outlets of the second small desalting chambers d2, d4, and d6, respectively. With the above configuration, the water to be treated is first supplied to the first small desalting chambers d1, d3, and d5 and desalted. And the to-be-processed water which passed 1st small desalination chamber d1, d3, d5 is supplied to 2nd small desalination chamber d2, d4, d6, is further desalted, and is discharged | emitted as treated water. Moreover, since the structure of the concentrated water inflow line 48, the concentrated water outflow line 50, etc. is the same structure as the electric deionized water manufacturing apparatus 1 of FIG. 14, description is abbreviate | omitted.

  An example of an operation method in the case of producing deionized water by the electric deionized water production apparatus 2 according to this embodiment will be described below. First, in a state where a direct current is passed between the cathode 24 and the anode 26, water to be treated is introduced from the first inflow line 36 and concentrated water is introduced from the concentrated water inflow line 48. The treated water that has flowed in from the first inflow line 36 flows through the first small desalting chambers d1, d3, and d5, and the cations are removed when passing through the packed bed of the cation exchanger 46. Further, the treated water that has passed through the first outflow line 38 of the first small desalination chambers d1, d3, d5 passes through the second inflow line 40 of the second small desalination chambers d2, d4, d6, When flowing through the small desalting chambers d2, d4, d6 and passing through the packed bed of the anion exchanger 20, anions such as carbonic acid (free carbonic acid, bicarbonate ion, carbonate ion) and silica are removed, and treated water (deionized) Water) is obtained from the second outlet line 42. Further, the concentrated water flowing in from the concentrated water inflow line 48 flows through the concentration chambers 16a and 16b, receives ions moving through the cation exchange membrane 10 and the anion exchange membrane 14, and is used as concentrated water obtained by concentrating the ions. It flows out from the concentrated water outflow line 50. Furthermore, the electrode water flowing in from the concentrated water inflow line 48 (electrode water inflow line) flows out from the concentrated water outflow line 50 (electrode water outflow line).

  Carbonic acid (free carbonic acid, bicarbonate ion, carbonate ion) captured by the anion exchanger 20 in the second small desalting chambers d2, d4, d6 is other ions captured by the hydroxide ion or the anion exchanger 20. It passes through the anion exchange membrane 14 on the anode side together with the anion component, and moves to the concentration chambers 16a and 16b. In the present embodiment, since the monolithic organic porous cation exchanger 23 is disposed between the anion exchanger 22 and the cation exchange membrane 10 in the concentration chambers 16a and 16b, as described above, the high-concentration carbonic acid is used. The gas-containing aqueous solution layer is generated on or inside the monolithic organic porous cation exchanger 23 in contact with the anion exchanger 22, and the carbon dioxide gas flows out of the concentration chambers 16 a and 16 b together with the concentrated water before contacting the cation exchange membrane 10. Is done. Even if the carbon dioxide gas reaches the cation exchange membrane 10, the amount of carbon dioxide permeating the cation exchange membrane 10 is reduced because it is diluted (lowered in concentration) in the monolithic organic porous cation exchanger 23. It is greatly reduced. Therefore, it is possible to suppress the carbon dioxide gas from moving through the cation exchange membrane 10 to the first small desalting chambers d3 and d5 and backdiffusing into the water to be treated.

  In the present embodiment, the thickness of the first small desalting chambers d1, d3, d5 or the second small desalting chambers d2, d4, d6 is not particularly limited, but the first small desalting chambers d1, d3, d5 are not limited. If the thickness is 0.8 to 600 mm, preferably 2 to 100 mm, and the thickness of the second small desalting chambers d2, d4 and d6 is 0.8 to 600 mm, preferably 6 to 100 mm, low electrical resistance and This is preferable in that high current efficiency can be obtained. If the thickness of the first small desalting chambers d1, d3, d5 is less than 0.8 mm, sufficient residence time cannot be secured, and the water quality tends to deteriorate. On the other hand, if it exceeds 600 mm, the electric resistance is too large, and the stable operation of the apparatus tends to be hindered. Similarly, if the thickness of the second small desalting chambers d2, d4, d6 is less than 0.8 mm, sufficient residence time cannot be secured, and the water quality tends to deteriorate. On the other hand, if it exceeds 600 mm, the increase in electrical resistance tends to be more significant than the increase in current efficiency.

  The ion exchanger used as the anion exchanger (20, 32) and cation exchanger (34, 46) may be any substance as long as it has an ion exchange function, such as an ion exchange resin and an ion exchange fiber. May be combined.

  Examples of the anion exchanger 22 filled in the concentration chambers 16a and 16b include strong basic anion exchangers. Examples of the anion exchanger include anion exchange resins, anion exchange fibers, and organic porous anion exchangers described in JP-A No. 2002-306976. The strong basic anion exchanger may partially contain a weak basic anion exchange group. The anion exchange resin has an advantage that the reaction is sufficiently performed even when the free carbonic acid concentration is low, and scale generation can be suppressed. Moreover, it is preferable that the particle size of the anion exchange resin is uniform in that the differential pressure in the concentration chamber is reduced.

  Although it does not restrict | limit especially as thickness of the concentration chambers 16a and 16b, 0.5 mm-60 mm are preferable, and 1 mm-10 mm are especially preferable. If it is less than 0.5 mm, even if the anion exchanger 22 is filled, it becomes difficult to obtain an effect of suppressing the occurrence of scale, and the water flow differential pressure tends to increase. On the other hand, if it exceeds 60 mm, the electrical resistance increases and the power consumption tends to increase.

  In the electric deionized water production apparatus, the treatment amount (SV, LV), the energization amount, and other operating conditions can be appropriately set according to the properties of the water to be treated.

In the present embodiment, there is no particular restriction on the water to be treated, but even water to be treated that contains a large amount of carbonic acid components can prevent carbonation of the final treated water. Examples of water to be treated containing a large amount of carbonic acid component include tap water or water obtained by treating tap water with an RO membrane or the like. Domestic tap water usually contains a hardness component in addition to a carbonic acid component, but according to the present embodiment, the concentration chambers 16a and 16b are filled with the anion exchanger 22, and thus moved to the concentration chambers 16a and 16b. Ca ²⁺ ions and Mg ²⁺ ions are hardly combined with carbonate ions (CO ₃ ²⁻ ) on the surface of the anion exchange membrane 14 in the concentration chambers 16a and 16b to produce a hardness scale, and the channels are blocked in the concentration chambers 16a and 16b. There is almost no such thing.

(Example)
Next, the present invention will be specifically described by way of examples, but this is merely an example and does not limit the present invention.

Reference example 1
(Step I; production of monolith intermediate)
9.28 g of styrene, 0.19 g of divinylbenzene, 0.50 g of sorbitan monooleate (hereinafter abbreviated as SMO) and 0.26 g of 2,2′-azobis (isobutyronitrile) were mixed and dissolved uniformly. Next, the styrene / divinylbenzene / SMO / 2,2′-azobis (isobutyronitrile) mixture is added to 180 g of pure water, and a vacuum stirring defoaming mixer (manufactured by EM Corp.) which is a planetary stirring device. Was used under reduced pressure in a temperature range of 5 to 20 ° C. to obtain a water-in-oil emulsion. The emulsion was immediately transferred to a reaction vessel, and after sealing, it was allowed to polymerize at 60 ° C. for 24 hours. After completion of the polymerization, the content was taken out, extracted with isopropanol, and then dried under reduced pressure to produce a monolith intermediate having a continuous macropore structure. The average diameter of the openings (mesopores) where the macropores and macropores of the monolith intermediate were measured by mercury porosimetry was 40 μm, and the total pore volume was 15.8 ml / g.

(Manufacture of composite monolith)
Next, 36.0 g of styrene, 4.0 g of divinylbenzene, 60 g of 1-decanol, and 0.4 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were mixed and dissolved uniformly (step II). The 10-hour half-life temperature of 2,2′-azobis (2,4-dimethylvaleronitrile) used as the polymerization initiator was 51 ° C. The amount of divinylbenzene used is 6.6 mol% with respect to the total amount of styrene and divinylbenzene used in Step II, while the crosslink density of the monolith intermediate is 1.3 mol%, and the crosslink density ratio is 5.1 times. Met. Next, the monolith intermediate was cut into a disk shape having an outer diameter of 70 mm and a thickness of about 20 mm, and 3.2 g was collected. The separated monolith intermediate is placed in a reaction vessel having an inner diameter of 73 mm, immersed in the styrene / divinylbenzene / 1-decanol / 2,2′-azobis (2,4-dimethylvaleronitrile) mixture, and removed in a vacuum chamber. After bubbling, the reaction vessel was sealed and allowed to polymerize at 60 ° C. for 24 hours. After completion of the polymerization, the monolith-like contents having a thickness of about 30 mm were taken out, subjected to Soxhlet extraction with acetone, and then dried under reduced pressure at 85 ° C. overnight (step III).

  The results of observing the internal structure of the composite monolith (dried body) composed of the styrene / divinylbenzene copolymer thus obtained by SEM are shown in FIGS. The SEM images in FIGS. 1 to 3 are different in magnification, and are images at arbitrary positions on a cut surface obtained by cutting a monolith at an arbitrary position. As apparent from FIGS. 1 to 3, the composite monolith has a continuous macropore structure, and the surface of the skeletal phase constituting the continuous macropore structure is coated with particles having an average particle diameter of 4 μm. The rate was 80%. Moreover, the ratio for which the particle body with a particle size of 3-5 micrometers occupied to the whole particle body was 90%.

  Moreover, the average diameter of the opening of the composite monolith measured by mercury porosimetry was 16 μm, and the total pore volume was 2.3 ml / g. The results are summarized in Tables 1 and 2. In Table 1, the preparation column shows the vinyl monomer, the crosslinking agent, the organic solvent used in Step II, and the monolith intermediate obtained in Step I in order from the left. Further, the particle bodies and the like are shown as particles.

(Production of complex monolith cation exchanger)
The composite monolith produced by the above method was cut into a disk shape having an outer diameter of 70 mm and a thickness of about 15 mm. The weight of the monolith was 19.6 g. To this, 1500 ml of dichloromethane was added and heated at 35 ° C. for 1 hour, then cooled to 10 ° C. or less, 98.9 g of chlorosulfuric acid was gradually added, and the temperature was raised and reacted at 35 ° C. for 24 hours. Thereafter, methanol was added to quench the remaining chlorosulfuric acid, which was then washed with methanol to remove dichloromethane and further washed with pure water to obtain a composite monolith cation exchanger.

  The swelling rate before and after the reaction of the obtained cation exchanger was 1.3 times, and the ion exchange capacity per volume was 1.11 mg equivalent / ml in a water wet state. The average diameter of the openings of the organic porous ion exchanger in the water wet state was 21 μm as estimated from the value of the organic porous body and the swelling ratio of the cation exchanger in the water wet state. The average particle size of the particles was 5 μm. The particle coverage of the skeletal surface with all particles was 80%, and the total pore volume was 2.3 ml / g. Moreover, the ratio for which the particle body of 4-7 micrometers of particle | grains accounts to the whole particle body was 90%. The differential pressure coefficient, which is an index of pressure loss when water is permeated, is 0.057 MPa / m · LV, which is a lower pressure loss than that required for practical use. It was. Further, the length of the ion exchange zone was 9 mm, showing a remarkably short value. The results are summarized in Table 2.

  Next, in order to confirm the distribution state of the sulfonic acid group in the composite monolith cation exchanger, the distribution state of sulfur atoms was observed by EPMA. The results are shown in FIGS. 4 and 5, the left and right photographs correspond to each other. FIG. 4 shows the distribution of sulfur atoms on the surface of the cation exchanger, and FIG. 5 shows the distribution of sulfur atoms in the cross-section (thickness) direction of the cation exchanger. 4 and 5, it can be seen that the sulfonic acid groups are uniformly introduced on the skeleton surface of the cation exchanger and inside the skeleton (cross-sectional direction).

Reference Examples 2-5
(Manufacture of composite monolith)
The amount of vinyl monomer used, the amount of crosslinking agent used, the type and amount of organic solvent used, the porous structure of the monolith intermediate that coexists during polymerization in step III, the crosslinking density and the amount used, and the polymerization temperature are shown in Table 1. A monolith was produced in the same manner as in Reference Example 1 except for the change. The results are shown in Tables 1 and 2. Moreover, the result of having observed the internal structure of composite monolith (dry body) by SEM is shown in FIGS. 6 to 8 are of Reference Example 2, FIGS. 9 and 10 are of Reference Example 3, FIG. 11 is of Reference Example 4, and FIGS. 12 and 13 are of Reference Example 5. For Reference Example 2, the crosslinking density ratio (2.5 times), for Reference Example 3, the type of organic solvent (PEG; molecular weight 400), for Reference Example 4, the vinyl monomer concentration (28.0%), Reference Example For No. 5, the polymerization temperature (40 ° C .; 11 ° C. lower than the 10-hour half-life temperature of the polymerization initiator) was produced under conditions satisfying the production conditions of the present invention. From FIG. 6 to FIG. 13, what adhered to the skeleton surface of the composite monoliths of Reference Examples 3 to 5 were protrusions rather than particles. The “particle average diameter” of the protrusion is the average diameter of the protrusions (maximum diameter). From FIG. 6 to FIG. 13 and Table 2, the average diameter of the particles adhering to the surface of the monolith skeleton of Reference Examples 2 to 6 is 3 to 8 μm, and the particle coverage of the skeleton surface by all particles is 50 to 95%. there were. In addition, the proportion of Reference Example 2 in which particles having a particle diameter of 3 to 6 μm occupy the entire particle body is 80%, and the ratio of Reference Example 3 in which protrusions having a particle diameter of 3 to 10 μm occupy the entire particle is 80%. In Reference Example 4, the proportion of particles having a particle diameter of 3 to 5 μm in the total particle body was 90%, and in Reference Example 5, the proportion of particles having a particle diameter of 3 to 7 μm in the entire particle body was 90%. .

(Production of complex monolith cation exchanger)
The composite monolith produced by the above method was reacted with chlorosulfuric acid in the same manner as in Reference Example 1 to produce a composite monolith cation exchanger. The results are shown in Table 2. The average diameter of the continuous pores of the composite monolith cation exchanger in Reference Examples 2 to 5 is 21 to 52 μm, the average diameter of the particles attached to the skeleton surface is 5 to 13 μm, the skeleton surface due to all the particles, etc. The particle coverage was as high as 50 to 95%, the differential pressure coefficient was as small as 0.010 to 0.057 MPa / m · LV, and the ion exchange zone length was as extremely small as 8 to 12 mm. Moreover, the ratio for which the particle body with a particle size of 5-10 micrometers occupied to the whole particle body was 90%.

Reference Example 6
(Manufacture of monoliths)
Except for changing the usage amount of the vinyl monomer, the usage amount of the crosslinking agent, the type and usage amount of the organic solvent, and the usage amount of the monolith intermediate coexisting during the polymerization in Step III to the blending amounts shown in Table 1, Example 1 and A monolith was produced in a similar manner. The results are shown in Tables 1 and 2. From the SEM photograph (not shown), the formation of particles and protrusions was not observed at all on the skeleton surface. From Table 1 and Table 2, when a monolith is produced under conditions deviating from the specific production conditions of the present invention, that is, conditions deviating from the requirements (1) to (5) above, particle formation on the surface of the monolith skeleton is caused. It turns out that it is not recognized.

(Production of monolith cation exchanger)
The monolith produced by the above method was reacted with chlorosulfuric acid in the same manner as in Reference Example 1 to produce a monolith cation exchanger. The results are shown in Table 2. The obtained monolith cation exchanger had an ion exchange zone length of 26 mm, which was a large value as compared with Reference Examples 1 to 5.

Reference Examples 7-9
(Manufacture of monoliths)
The amount of vinyl monomer used, the amount of crosslinking agent used, the type and amount of organic solvent used, the porous structure of the monolith intermediate that coexists during polymerization in step III, the crosslinking density, and the amount used were changed to the amounts shown in Table 1. Produced a monolith in the same manner as in Reference Example 1. The results are shown in Tables 1 and 2. For Reference Example 7, the crosslinking density ratio (0.2 times), for Reference Example 8, the type of organic solvent (2- (2-methoxyethoxy) ethanol; molecular weight 120), and for Reference Example 9, the polymerization temperature (50 And 1 ° C. lower than the 10-hour half-life temperature of the polymerization initiator). The results are shown in Table 2. For the monoliths of Reference Examples 7 and 9, no particles were generated on the skeleton surface. In Reference Example 8, the isolated product was transparent, and the porous structure was collapsed and disappeared.

(Production of monolith cation exchanger)
Except for Reference Example 8, the organic porous material produced by the above method was reacted with chlorosulfuric acid in the same manner as in Reference Example 6 to produce a monolith cation exchanger. The results are shown in Table 2. The obtained monolith cation exchanger had an ion exchange zone length of 23 to 26 mm, which was a large value as compared with Reference Examples 1 to 5.

FIG. 17 is a schematic configuration diagram showing a test cell for measuring the amount of carbonic acid components moving from the concentration chamber to the desalting chamber. As shown in FIG. 17, an anion exchange membrane 64 and a first cation exchange membrane 66 are partitioned between a cathode chamber 58 filled with an anion exchange resin 56 and an anode chamber 62 filled with a cation exchange resin 60. The concentration chamber 68, the first cation exchange membrane 66 and the first cation exchange membrane 66 in which the monolithic organic porous cation exchanger 54 is disposed between the anion exchange resin 56 and the first cation exchange membrane 66 are filled with the anion exchange resin 56. A test cell 3 having a demineralization chamber 72 filled with a cation exchange resin 60 in a chamber partitioned by a dication exchange membrane 70 is prepared, and a carbonic acid component that moves from the concentration chamber 68 to the demineralization chamber 72 under the following conditions The amount was measured. In Example 1, ultrapure water was passed through the desalting chamber 72 and the electrode chambers (58, 62), and a NaHCO ₃ solution (carbonate concentration 30 mg-CaCO ₃ / L) was passed through the concentration chamber 68. .

<Ion exchanger used>
Monolithic organic porous cation exchanger: Composite monolith cation exchanger of Reference Example 4 Cation exchange resin: Amberlite IRA402BL manufactured by Rohm and Haas
Anion exchange resin: Rohm and Haas, Amberlite IRA402BL
First cation exchange membrane, second cation exchange membrane: manufactured by Astom Co., Ltd., C66-10F
Anion exchange membrane: manufactured by Astom Co., Ltd., AHA
<EDI size>
Test cell: 10cm long x 10cm wide x 8mm thick
<Flow conditions>
Ultrapure water, NaHCO ₃ solution, CO ₂ -containing solution: 8000 ml / hr
<Current conditions>
Constant current: 0.5 A / dm ²

Instead of the solution of NaHCO _3, except for using the CO ₂ containing solution (carbonate ion concentration 30mg-CaCO ₃ / L) was performed under the same conditions as in Example 1.

Comparative Example 1
The same procedure as in Example 1 was performed except that the composite monolith cation exchanger 54 was not disposed between the anion exchange resin 56 and the first cation exchange membrane 66 in the concentration chamber 68.

Comparative Example 2
The same procedure as in Example 2 was performed except that the composite monolith cation exchanger 54 was not disposed between the anion exchange resin 56 and the first cation exchange membrane 66 in the concentration chamber 68.

The amount of carbonic acid in the treated water (ultra pure water) discharged from the desalting chambers of Examples 1 and 2 and Comparative Examples 1 and 2 was measured. Specifically, inorganic carbon (IC) in the treated water was measured with a TOC meter (A-1000) manufactured by Altena, and the amount of carbonic acid in the treated water was measured using this as carbonic acid. The treated water discharged from the desalting chambers of Comparative Example 1 and Comparative Example 2 contained carbonic acid components of 8400 μg-CaCO ₃ / hr and 9000 μg-CaCO ₃ / hr. On the other hand, the treated water discharged from the desalting chambers of Examples 1 and 2 contained 300 μg-CaCO ₃ / hr and 340 μg-CaCO ₃ / hr of carbonic acid components. Comparative Examples 1 and 2 The amount of carbonic acid component was greatly reduced. That is, by disposing the composite monolith cation exchanger between the anion exchange resin and the cation exchange membrane in the concentration chamber, it is possible to suppress the carbonic acid component in the concentration chamber from moving to the desalting chamber via the cation exchange membrane. confirmed.

  1, 2 Electric deionized water production apparatus, 3 test cell, 10, 66, 70 cation exchange membrane, 12 intermediate ion exchange membrane, 14, 64 anion exchange membrane, 16a, 16b, 68 concentration chamber, 18 mixture, 20 , 22, 32 Anion exchanger, 23 monolithic organic porous cation exchanger, 24 cathode, 25 frame, 26 anode, 28, 30, 58, 62 electrode chamber, 34, 46 cation exchanger, 36 first inflow line 38 First outflow line, 40 Second inflow line, 42 Second outflow line, 48 Concentrated water inflow line, 50 Concentrated water outflow line, 54 Monolithic organic porous cation exchanger, 56 Anion exchange resin, 60 Cation exchange resin 72, D1, D2, D3 desalting chamber, d1, d3, d5 first small desalting chamber, d2, d4, d6 second small desalting chamber

Claims (6)

Between the anode and the cathode, it is partitioned by a cation exchange membrane on the cathode side and an anion exchange membrane on the anode side, and a desalting chamber filled with an ion exchanger, through the cation exchange membrane and the anion exchange membrane An electric deionized water production apparatus that is provided on both sides of the demineralization chamber and has a concentration chamber filled with an anion exchanger,
Between the anion exchanger in the concentrating chamber and the cation exchange membrane, an organic porous body composed of a continuous skeleton phase and a continuous pore phase, and a large number of 4 to 40 μm in diameter fixed to the skeleton surface of the organic porous body A composite structure with a large number of protrusions having a size of 4 to 40 μm formed on the surface of the skeleton of the particle body or the organic porous body, and having an average pore diameter of 10 to 150 μm in the wet state. A monolithic organic porous cation exchanger having a pore volume of 0.5 to 5 ml / g and an ion exchange capacity of 0.2 mg equivalent / ml or more per volume in a water-wet state is disposed. Type deionized water production equipment.   2. The electric type according to claim 1, wherein the organic porous body is a continuous macropore structure in which bubble-shaped macropores overlap each other, and the overlapping portion forms an opening having an average diameter of 30 to 150 μm when wet. Deionized water production equipment.   The organic porous body is a three-dimensionally continuous skeleton having an average thickness of 1 to 60 μm in a water-wet state, and a three-dimensionally continuous skeleton having an average diameter of 10 to 100 μm in a water-wet state between the skeletons. 2. The electric deionized water production apparatus according to claim 1, wherein the apparatus is a co-continuous structure composed of pores. Between the anode and the cathode, it is partitioned by a cation exchange membrane on the cathode side and an anion exchange membrane on the anode side, and a desalting chamber filled with an ion exchanger, through the cation exchange membrane and the anion exchange membrane A deionized water production method for producing deionized water using an electric deionized water production apparatus that is provided on both sides of the demineralization chamber and is provided with a concentration chamber filled with an anion exchanger. An organic porous body composed of a continuous skeleton phase and a continuous pore phase between the anion exchanger in the concentration chamber and the cation exchange membrane, and a diameter of 4 to 40 μm fixed to the skeleton surface of the organic porous body A composite structure with a large number of particles or a large number of protrusions having a size of 4 to 40 μm formed on the skeleton surface of the organic porous body, and having an average pore diameter of 10 to 150 μm in a water-wet state, Total pore volume 0.5-5ml / g, water wet Method for producing deionized water, which comprises placing a monolith-shaped organic porous cation exchanger is ion exchange capacity 0.2mg equivalent / ml or more per volume in state.   5. The deionization according to claim 4, wherein the organic porous body is a continuous macropore structure in which bubble-shaped macropores overlap each other, and the overlapping portion forms an opening having an average diameter of 30 to 150 μm when wet. Water production method.   The organic porous body is a three-dimensionally continuous skeleton having an average thickness of 1 to 60 μm in a water-wet state, and a three-dimensionally continuous skeleton having an average diameter of 10 to 100 μm in a water-wet state between the skeletons. The method for producing deionized water according to claim 4, which is a co-continuous structure composed of pores.