JP2014028370A - Ion adsorption module and water treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adsorption module capable of reducing a differential pressure caused by water passage, and maintaining an ion exchanger in a short length even when a flow rate is raised, and having a large ion-exchange capacity per volume, and to provide a water treatment method.SOLUTION: An ion adsorption module includes: a container having an opening through which at least water to be treated flows in; and an organic porous ion exchanger which is a continuous macroporous structure in which bubble-shaped macropores filled in the container are superposed on one another and the superposed portions form openings having an average diameter of 30-300 μm in a water-wet state, has a total pore volume of 0.5-5 ml/g and an ion exchange capacity per volume in the water-wet state of 0.4-5 mg equivalent/ml, with the area of a skeleton portion appearing on a cross section in the SEM image of a cut surface of the continuous macroporous structure (a dry body) occupying 25-50% of the image area.

Description

  The present invention relates to an ion adsorption module and a water treatment method having a remarkably short ion exchange zone length.

  Conventionally, ion exchangers are typified by polymer synthetic resins collectively referred to as ion exchange resins, and if classified according to product shape, granular or flake ion exchange resins, membrane ion exchange membranes, and fibrous ion exchange resins It can be classified into ion exchange fibers. In addition to the granular ion exchange resin, organic porous ion exchangers having continuous pores are also known.

  For example, in Japanese Patent Application Laid-Open No. 2004-82027, a container having at least an opening through which water to be treated flows, a macropore filled in the container, and a mesopore having an average diameter of 1 to 1000 μm in the wall of the macropore are provided. 3 having an open cell structure, a total pore volume of 1 ml / g to 50 ml / g, an ion exchange group uniformly distributed, and an ion exchange capacity of 0.5 mg equivalent / g dry porous body or more An ion adsorption module comprising an organic porous ion exchanger having a dimensional network structure is disclosed.

  According to the ion adsorption module of Japanese Patent Application Laid-Open No. 2004-82027, the filling of the ion exchanger is extremely easy, and the packed bed does not move even in the upward flow. Further, in the water treatment method using this ion adsorption module, the ion exchange zone length can be kept short even when the flow rate is increased, the volume of the ion exchanger device can be reduced, and a small amount of adsorbed ions can be achieved. Since no leakage occurs, the reproduction frequency is reduced and the processing efficiency can be improved. Japanese Patent Laid-Open No. 2002-306976 discloses details of a method for producing this organic porous ion exchanger.

JP 2004-82027 A (Claims) JP 2002-306976 A

  However, the organic porous ion exchanger used in the ion adsorption module of Japanese Patent Application Laid-Open No. 2004-82027 describes a common monolithic opening (mesopore) of 1 to 1,000 μm, but has a total pore volume of 5 ml. For monoliths with a small pore volume of / 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 those having an average diameter of 20 μm or more are substantially manufactured. Can not. For this reason, there existed a problem that water flow differential pressure | voltage will become large. In addition, when the average diameter of the openings is around 20 μm, the total pore volume also increases accordingly, so that the ion exchange capacity per volume decreases, the ion exchange zone length is long, and the module replacement frequency is high. There was a problem of becoming.

  Accordingly, an object of the present invention is to provide an ion adsorption module that is extremely easy to fill with an ion exchanger. Another object of the present invention is to reduce the water differential pressure and to increase the flow rate even if the flow rate increases. The band length can be kept short, the ion exchange capacity per volume is large, and a minute leak of adsorbed ions does not occur, so the exchange frequency is reduced or the regeneration frequency is lowered, and the processing efficiency can be improved. Another object is to provide an ion adsorption module and a water treatment method.

  Under such circumstances, the present inventors have conducted intensive studies, and as a result, the existence of a monolithic organic porous material (intermediate) having a relatively large pore volume obtained by the method described in JP-A-2002-306976. Below, if the vinyl monomer and the crosslinking agent are allowed to stand in a specific organic solvent, a monolith having a large opening diameter and a thicker skeleton than that of the intermediate organic porous material can be obtained. When the ion exchange group is introduced into the monolith, the swelling is large because it is thick, so that the opening can be further increased. When used as an adsorbent for an ion adsorption module, the exchanger can reduce the water differential pressure and keep the ion exchange zone length short even when the flow rate increases. And the ion exchange capacity per volume is large, and a minute leak of adsorbed ions does not occur. Therefore, the exchange frequency is reduced or the regeneration frequency is reduced, and the processing efficiency can be improved. It came to be completed.

  In addition, as a result of intensive studies, the present inventors have found that an aromatic monolith-like organic porous material intermediate having a large pore volume obtained by the method described in JP-A No. 2002-306976 is aromatic. If a vinyl monomer and a crosslinking agent are allowed to stand in a specific organic solvent, they are composed of a three-dimensionally continuous aromatic vinyl polymer skeleton and three-dimensionally continuous pores between the skeleton phases. It is possible to obtain an intertwined hydrophobic monolith with a co-continuous structure. This co-continuous monolith has a high continuity of pores, is not biased in size, and has a low pressure loss during fluid permeation. Since the skeleton of the co-continuous structure is thick, if an ion exchange group is introduced, a monolithic organic porous ion exchanger having a large ion exchange capacity per volume can be obtained, and the monolithic organic porous ion exchanger (hereinafter, “ Second When used as an adsorbent for an ion adsorption module, the “Norris ion exchanger” can also reduce the water flow differential pressure and increase the ion exchange zone length even when the flow rate is increased, as with the first monolith ion exchanger. The ion exchange capacity per volume is large and a small amount of adsorbed ions does not leak, so that the exchange frequency is reduced or the regeneration frequency is reduced, and the processing efficiency can be improved. As a result, the present invention has been completed.

  That is, according to the present invention, at least a container having an opening through which water to be treated flows and bubble-shaped macropores filled in the container overlap each other, and the overlapping part becomes an opening having an average diameter of 30 to 300 μm in a wet state. Continuous macropore structure, total pore volume of 0.5 to 5 ml / g, ion exchange capacity per volume in a water-wet state of 0.4 to 5 mg equivalent / ml, and ion exchange group is porous ion exchange Organic porous ion exchange in which the skeleton area is 25 to 50% in the image area in the SEM image of the cut surface of the continuous macropore structure (dried body) evenly distributed in the body An ion adsorption module comprising a body is provided.

  In addition, the present invention provides a cross-linking structural unit in an amount of 0.3 to 5.0 mol% in all structural units into which at least an opening through which water to be treated flows and an ion exchange group filled in the container are introduced. A co-continuous structure comprising a three-dimensionally continuous skeleton having a thickness of 1 to 60 μm and a three-dimensionally continuous pore having a diameter of 10 to 100 μm between the skeletons and comprising an aromatic vinyl polymer. The total pore volume is 0.5 to 5 ml / g, the ion exchange capacity per volume in a wet state of water is 0.3 to 5 mg equivalent / ml, and the ion exchange group is the porous ion exchanger. An ion adsorption module comprising an organic porous ion exchanger uniformly distributed therein is provided.

  In addition, the present invention is a continuous macropore structure in which a granular ion exchange resin-filled layer and bubble-shaped macropores overlap each other, and the overlapping portion is an opening having an average diameter of 30 to 300 μm in a wet state of water. The volume is 0.5 to 5 ml / g, the ion exchange capacity per volume in a wet state of water is 0.4 to 5 mg equivalent / ml, and the ion exchange groups are uniformly distributed in the porous ion exchanger, And in the SEM image of the cut surface of the continuous macropore structure (dried body), the organic porous ion exchanger packed layer having a skeleton area of 25 to 50% in the image region in this order from the upstream side in this order. The present invention provides an ion adsorption module characterized in that it is laminated.

  The present invention also includes a granular ion exchange resin packed layer and a thickness composed of an aromatic vinyl polymer containing 0.3 to 5.0 mol% of a crosslinked structural unit among all the structural units into which ion exchange groups are introduced. Is a co-continuous structure composed of a three-dimensionally continuous skeleton having a diameter of 1 to 60 μm and three-dimensionally continuous pores having a diameter of 10 to 100 μm between the skeletons, and the total pore volume is 0. Organic pores having an ion exchange capacity of 0.3 to 5 mg equivalent / ml per volume in a water-wet state and having an ion exchange group uniformly distributed in the porous ion exchanger It is an object of the present invention to provide an ion adsorption module characterized in that a porous ion exchanger packed layer is laminated in this order from the upstream side.

  Further, the present invention is a continuous macropore structure in which cellular macropores overlap each other, and the overlapping portion is an opening having an average diameter of 30 to 300 μm in a wet state of water, and has a total pore volume of 0.5 to 5 ml / g, The ion exchange capacity per volume in a wet state of water is 0.4 to 5 mg equivalent / ml, the ion exchange groups are uniformly distributed in the porous ion exchanger, and the continuous macropore structure (dried body) In the SEM image of the cut surface of), an ionic impurity in the treated water is obtained by bringing the treated water into contact with the organic porous ion exchanger having an area of 25 to 50% of the image region in the image area. A water treatment method characterized by adsorbing and removing water is provided.

  The present invention also provides a three-dimensional thickness of 1 to 60 μm in thickness composed of an aromatic vinyl polymer containing 0.3 to 5.0 mol% of a crosslinked structural unit among all the structural units into which ion exchange groups have been introduced. A co-continuous structure composed of a continuous skeleton and three-dimensionally continuous pores having a diameter of 10 to 100 μm between the skeletons, and has a total pore volume of 0.5 to 5 ml / g, An organic porous ion exchanger having an ion exchange capacity per volume in a wet state of 0.3 to 5 mg equivalent / ml and an ion exchange group uniformly distributed in the porous ion exchanger and water to be treated. It is intended to provide a water treatment method characterized by adsorbing and removing ionic impurities in the water to be treated by contacting them.

  According to the present invention, the porous ion exchanger can be easily produced, for example, as a block shape that fits into a filling container, and filling is also easy. Moreover, it can apply to both the continuous water flow processing method generally employ | adopted with the conventional module, and the batch processing method performed by throwing in the water in a storage container or a storage tank. In addition, when the content of ionic impurities is very small in the continuous water treatment method, the water differential pressure can be reduced with a compact device, and the ion exchange zone length should be kept short even when the flow rate is increased. In addition, since the ion exchange capacity per volume is large and a minute leak of adsorbed ions does not occur, the exchange frequency is reduced or the regeneration frequency is lowered, and the processing efficiency can be improved.

It is a SEM image of the monolith in the 1st monolith ion exchanger. It is an EPMA image which showed the distribution state of the sulfur atom in the surface of the monolith of FIG. 2 is an EPMA image showing a distribution state of sulfur atoms in the cross-section (thickness) direction of the monolith of FIG. It is a figure which shows the correlation of the differential pressure | voltage coefficient of the reference examples 1-11 and the reference examples 20-23, and the ion exchange capacity per volume. It is a manual transfer of the skeleton part that appears as a cross section of the SEM image of FIG. It is the figure which showed typically the co-continuous structure of the 2nd monolith ion exchanger. It is a SEM image of the monolith intermediate in a bicontinuous structure. It is a SEM image of the monolith cation exchanger which has a bicontinuous structure. It is the EPMA image which showed the distribution state of the sulfur atom in the surface of the monolith cation exchanger which has a bicontinuous structure. It is the EPMA image which showed the distribution state of the sulfur atom in the cross section (thickness) direction of the monolith cation exchanger which has a bicontinuous structure. It is a SEM image of the other monolith cation exchanger which has a bicontinuous structure. It is the SEM photograph of the organic porous body of the former (Unexamined-Japanese-Patent No. 2002-306976).

  In the ion adsorption module according to the embodiment of the present invention, the container is filled with the first monolith ion exchanger or the second monolith ion exchanger. In the present specification, “monolithic organic porous body” is simply “monolith”, “monolithic organic porous ion exchanger” is simply “monolith ion exchanger”, and “monolithic organic porous intermediate”. Is also simply referred to as “monolith intermediate”.

<Description of the first monolith ion exchanger>
The first monolith ion exchanger is obtained by introducing an ion exchange group into a monolith. Bubble-shaped macropores are overlapped with each other, and the overlapping portion is in a wet state with an average diameter of 30 to 300 μm, preferably 30. It is a continuous macropore structure having openings (mesopores) of ˜200 μm, particularly 35 to 150 μm. The average diameter of the opening of the monolith ion exchanger is larger than the average diameter of the opening of the monolith because the entire 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 at the time of water flow is increased, which is not preferable. If the average diameter of the openings is too large, contact between the fluid and the monolith ion exchanger becomes insufficient. As a result, the ion exchange characteristics deteriorate, which is not preferable. In the present invention, the average diameter of the opening of the monolith intermediate in the dry state, the average diameter of the opening of the monolith in the dry state, and the average diameter of the opening of the monolith ion exchanger in the dry state are values measured by a mercury intrusion method. It is. Further, the average diameter of the openings of the monolith ion exchanger in the wet state is a value calculated by multiplying the average diameter of the openings of the monolith ion exchanger in the dry state by the swelling rate. Specifically, the water-wet monolith ion exchanger has a diameter of x1 (mm), the water-wet monolith ion exchanger is dried, and the resulting dried monolith ion exchanger has a diameter of y1 ( mm), and the average diameter of the opening of the monolith ion exchanger in the dry state measured by the mercury intrusion method was z1 (μm), the average diameter of the opening of the monolith ion exchanger in the water wet state ( μm) is calculated by the following formula: “average diameter of openings of monolith ion exchanger in water wet state (μm) = z1 × (x1 / y1)”. In addition, the average diameter of the opening of the dried monolith before introduction of the ion exchange group, and the swelling ratio of the monolith ion exchanger in the water wet state relative to the dried monolith when the ion exchange group is introduced into the dried monolith. In this case, the average diameter in the water-wet state of the pores of the monolith ion exchanger can also be calculated by multiplying the average diameter of the opening of the monolith in the dry state by the swelling rate.

  In the first monolith ion exchanger, in the SEM image of the cut surface of the continuous macropore structure, the skeleton part area appearing in the cross section is 25 to 50%, preferably 25 to 45% in the image region. If the area of the skeleton part appearing in the cross section is less than 25% in the image region, it becomes a thin skeleton, which is not preferable because the ion exchange capacity per volume decreases, and if it exceeds 50%, the skeleton becomes too thick. Since the uniformity of ion exchange characteristics is lost, it is not preferable. In addition, the monolith described in JP-A-2002-346392 actually has a limit to the blending ratio in order to ensure a common opening even if the blending ratio of the oil phase part with respect to water is increased to make the skeleton portion thick. Yes, the maximum value of the skeleton part area appearing in the cross section cannot exceed 25% in the image region.

  The conditions for obtaining the SEM image may be any conditions as long as the skeleton part that appears in the cross section of the cut surface appears clearly. For example, the magnification is 100 to 600, and the photographic area is about 150 mm × 100 mm. SEM observation is preferably performed on three or more images, preferably five or more images, taken at arbitrary locations on an arbitrary cut surface of the monolith excluding subjectivity and at different locations. The monolith to be cut is in a dry state for use in an electron microscope. The skeleton part of the cut surface in the SEM image will be described with reference to FIGS. FIG. 5 is a transcribed skeleton that appears as a cross section of the SEM photograph of FIG. In FIGS. 1 and 5, what is generally indeterminate and shown in cross section is the “skeleton portion (reference numeral 12)” in the present invention, the circular hole shown in FIG. 1 is an opening (mesopore), and A relatively large curvature or curved surface is a macropore (reference numeral 13 in FIG. 5). The skeleton area shown in the cross section of FIG. 5 is 28% in the rectangular photographic region 11. Thus, the skeleton can be clearly determined.

  In the SEM photograph, the method for measuring the area of the skeletal part appearing in the cross section of the cut surface is not particularly limited, and after specifying the skeletal part by performing known computer processing or the like, calculation by automatic calculation or manual calculation by a computer or the like A method is mentioned. The manual calculation includes a method in which an indefinite shape is replaced with an aggregate such as a quadrangle, a triangle, a circle, or a trapezoid, and the areas are obtained by stacking them.

  The first monolith ion exchanger has a total pore volume of 0.5 to 5 ml / g, preferably 0.8 to 4 ml / g. If the total pore volume is less than 0.5 ml / g, the pressure loss during water passage is increased, which is not preferable. On the other hand, if the total pore volume exceeds 5 ml / g, the ion exchange capacity per volume decreases, which is not preferable. The monolith of the present invention has an average diameter of openings and a total pore volume in the above-mentioned range and is a bone skeleton. Excellent adsorption ability can be demonstrated. In the present invention, the total pore volume of the monolith (monolith intermediate, monolith, monolith ion exchanger) is a value measured by a mercury intrusion method. In addition, the total pore volume of the monolith (monolith intermediate, monolith, monolith ion exchanger) is the same both in the dry state and in the water wet state.

  In addition, the pressure loss at the time of making water permeate | transmit the 1st monolith ion exchanger is the pressure loss at the time of letting water flow through the column packed with 1 m of the porous body at a water flow velocity (LV) of 1 m / h (hereinafter referred to as the pressure loss). , “Differential pressure coefficient”), it is preferably in the range of 0.001 to 0.1 MPa / m · LV, more preferably 0.001 to 0.05 MPa / m · LV. If the differential pressure coefficient and the total pore volume are within this range, when this is used as an ion adsorbent, the contact area with the water to be treated is large, and smooth circulation of the water to be treated is possible. Since it has sufficient mechanical strength, it is preferable.

  The first monolith ion exchanger has an ion exchange capacity of 0.4 to 5 mg equivalent / ml per volume in a water-wet state. In the conventional monolithic organic porous ion exchanger having a continuous macropore structure different from the present invention as described in JP-A-2002-306976, in order to achieve a low pressure loss that is practically required, When the opening diameter is increased, the total pore volume is increased accordingly, so that the ion exchange capacity per volume is decreased, and the total pore volume is decreased to increase the exchange capacity per volume. In addition, since the opening diameter is reduced, the pressure loss increases. On the other hand, the monolith ion exchanger of the present invention can further increase the aperture diameter and thicken the skeleton of the continuous macropore structure (thicken the skeleton wall), so that the pressure loss during permeation can be reduced. Ion adsorption performance can be dramatically increased while keeping it low. If the ion exchange capacity per volume is less than 0.4 mg equivalent / ml, the amount of treated water to be treated before breakthrough is reduced and the frequency of module exchange is increased, which is not preferable. The ion exchange capacity per weight of the monolith ion exchanger of the present invention is not particularly limited. However, since the ion exchange groups are uniformly introduced to the surface of the porous body and the inside of the skeleton, 3 to 5 mg equivalent / g It is. The ion exchange capacity of a porous body in which ion exchange groups are introduced only on the surface cannot be determined unconditionally depending on the type of the porous body or ion exchange groups, but is at most 500 μg equivalent / g.

  In the first monolith ion exchanger, the material constituting the skeleton of the continuous macropore structure 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 50 mol%, preferably 0.3 to 5 mol% of crosslinked structural units with respect to all structural units constituting the polymer material. It is preferable. If the cross-linking structural unit is less than 0.3 mol%, it is not preferable because the mechanical strength is insufficient. On the other hand, if it exceeds 50 mol%, the porous body becomes brittle and the flexibility is lost. In particular, in the case of an ion exchanger, the amount of ion exchange groups introduced is decreased, which is not preferable. The type of the polymer material is not particularly limited, and examples thereof include aromatic vinyl polymers such as polystyrene, poly (α-methylstyrene), polyvinyl toluene, polyvinyl benzyl chloride, polyvinyl biphenyl, and polyvinyl naphthalene; polyolefins such as polyethylene and polypropylene; Poly (halogenated polyolefin) such as vinyl chloride and polytetrafluoroethylene; Nitrile-based polymer such as polyacrylonitrile; Cross-linking weight of (meth) acrylic polymer such as polymethyl methacrylate, polyglycidyl methacrylate, and polyethyl acrylate Coalescence is mentioned. The polymer may be a polymer obtained by copolymerizing a single vinyl monomer and a crosslinking agent, a polymer obtained by polymerizing a plurality of vinyl monomers and a crosslinking agent, or a blend of two or more types of polymers. It may be what was done. Among these organic polymer materials, the cross-linking weight of the aromatic vinyl polymer is high due to the ease of forming a continuous macropore structure, the ease of introducing ion-exchange groups and the high mechanical strength, and the high stability to acids and alkalis. A styrene-divinylbenzene copolymer and a vinylbenzyl chloride-divinylbenzene copolymer are particularly preferable materials.

  Examples of the ion exchange group of the first monolith ion exchanger 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; a quaternary ammonium group and a tertiary amino group And anion exchange groups such as secondary amino group, primary amino group, polyethyleneimine group, tertiary sulfonium group, and phosphonium group. If the ion exchange group is a cation exchanger, metals that have a particularly adverse effect on semiconductor devices can be effectively removed.

  In the first monolith ion exchanger, the introduced ion exchange groups are uniformly distributed not only on the surface of the porous body but also within the skeleton of the porous body. Here, “ion exchange groups are uniformly distributed” means that the distribution of ion exchange groups is uniformly distributed on the surface and inside the skeleton in the order of at least μm. The distribution of ion exchange groups can be confirmed relatively easily by using EPMA or the like. In addition, if the ion exchange groups are uniformly distributed not only on the surface of the monolith but also within the skeleton of the porous body, the physical and chemical properties of the surface and the interior can be made uniform, so that the swelling and shrinkage can be achieved. The durability against is improved.

(Method for producing first monolithic ion exchanger)
The first monolith ion exchanger is prepared by preparing a water-in-oil emulsion by stirring a mixture of oil-soluble monomer, surfactant and water that does not contain ion-exchange groups, and then polymerizing the water-in-oil emulsion. Step I for obtaining a monolithic organic porous intermediate having a continuous macropore structure having a total pore volume of 5 to 16 ml / g, a vinyl monomer, a crosslinking agent having at least two vinyl groups in one molecule, a vinyl monomer, Step II for preparing a mixture comprising an organic solvent and a polymerization initiator that dissolves the cross-linking agent but does not dissolve the polymer formed by polymerization of the vinyl monomer. The mixture obtained in Step II is allowed to stand still and in Step I. Polymerization is performed in the presence of the obtained monolithic organic porous intermediate to obtain a thick organic porous body having a skeleton thicker than the skeleton of the organic porous intermediate. It is obtained by performing the IV step of introducing an ion exchange group into the thick organic porous material obtained in the step III.

  In the first method for producing a monolithic ion exchanger, the step I may be performed in accordance with the method described in JP-A-2002-306976.

  In the production of the monolith intermediate of step I, the oil-soluble monomer that does not contain an ion exchange group includes, for example, an ion exchange group such as a carboxylic acid group, a sulfonic acid group, and a quaternary ammonium group, and is soluble in water. Low and lipophilic monomers may be mentioned. 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. However, a crosslinkable monomer such as divinylbenzene or ethylene glycol dimethacrylate is selected as at least one component of the oil-soluble monomer, and the content thereof is 0.3 to 50 mol%, preferably 0.3 to the total oil-soluble monomer. 5 mol% is preferable in that the mechanical strength necessary for introducing a large amount of ion-exchange groups in a later step can be obtained.

  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, azobisisobutyronitrile, azobiscyclohexanenitrile, azobiscyclohexanecarbonitrile, benzoyl peroxide, potassium persulfate, ammonium persulfate, Examples thereof include hydrogen oxide-ferrous chloride, sodium persulfate-sodium acid sulfite, and tetramethylthiuram disulfide.

  The mixing method for mixing the oil-soluble monomer not containing an ion exchange group, a surfactant, water, and a polymerization initiator to form a water-in-oil emulsion is not particularly limited. Method of mixing at once, oil-soluble monomer, surfactant and oil-soluble polymerization initiator oil-soluble component and water or water-soluble polymerization initiator water-soluble component separately and uniformly dissolved, A method of mixing the components 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, a porous structure having a thick skeleton is formed using the structure of the monolith intermediate as a template. 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 50 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. In particular, when the total pore volume is as large as 10 to 16 ml / g, in order to maintain a continuous macropore structure, it is preferable to contain 2 mol% or more of cross-linked structural units. On the other hand, if it exceeds 50 mol%, the porous body becomes brittle and the flexibility is lost.

  The type of the polymer material of the monolith intermediate is not particularly limited, and examples thereof include the same materials as the monolith polymer material described above. Thereby, the same polymer can be formed in the skeleton of the monolith intermediate, and the skeleton can be thickened to obtain a monolith having a uniform skeleton structure.

  The total pore volume of the monolith intermediate is 5 to 16 ml / g, preferably 6 to 16 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 water passage becomes large, 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 deviates from the continuous macropore structure, which is not preferable. In order to make the total pore volume of the monolith intermediate within the above numerical range, the ratio of the monomer and water may be about 1: 5 to 1:20.

  Moreover, the average diameter of the opening (mesopore) which is an overlap part of a macropore and a macropore is 20-200 micrometers in a monolith intermediate body in a dry state. 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 200 μm, the opening diameter of the monolith obtained after polymerizing the vinyl monomer becomes too large, and the contact between the water to be treated and the monolith ion exchanger becomes insufficient. As a result, the removal efficiency of ion components Is unfavorable because it decreases. 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.

  Step II consists of a vinyl monomer, a crosslinking agent having at least two vinyl groups in one molecule, an organic solvent and a polymerization initiator that dissolves the vinyl monomer and the crosslinking agent but does not dissolve the polymer formed by polymerization of the vinyl monomer. A step of preparing a mixture of 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 containing a polymerizable vinyl group in the molecule and having high solubility in an organic solvent, but is allowed to coexist in the polymerization system. It is preferred to select a vinyl monomer that produces the same or similar polymer material as the monolith intermediate. 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 at the time of polymerization. If the amount of vinyl monomer added is less than 3 times that of the porous material, the resulting monolith skeleton (the thickness of the monolith skeleton wall) cannot be made thick, and the adsorption capacity per volume and the volume after introduction of ion exchange groups. This is not preferable because the ion exchange capacity per unit becomes small. On the other hand, when the addition amount of vinyl monomer exceeds 40 times, the opening diameter becomes small, and the pressure loss at the time of passing water becomes large.

  As the crosslinking agent used in step II, a crosslinking agent containing at least two polymerizable vinyl groups in the molecule and having high solubility in an organic solvent is preferably used. Specific examples of the crosslinking agent include divinylbenzene, divinylnaphthalene, divinylbiphenyl, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, butanediol diacrylate, and the like. These crosslinking agents can be used singly or in combination of two or more. Preferred cross-linking agents are aromatic polyvinyl compounds such as divinylbenzene, divinylnaphthalene and divinylbiphenyl because of their high mechanical strength and stability to hydrolysis. The amount of the crosslinking agent used is preferably 0.3 to 50 mol%, particularly 0.3 to 5 mol%, based on the total amount of the vinyl monomer and the 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 50 mol%, the brittleness of the monolith proceeds and the flexibility is lost, and the introduction amount of ion exchange groups is reduced. It is preferable to use it so as to be approximately equal to the crosslinking density of the monolith intermediate coexisting during the polymerization of the vinyl monomer / crosslinking agent. If the amounts used of both are too large, the crosslink density distribution is biased in the produced monolith, and cracks are likely to occur during the ion exchange group introduction reaction.

  The organic solvent used in Step II is an organic solvent that dissolves the vinyl monomer and the crosslinking agent but does not dissolve the polymer formed by polymerization of the vinyl monomer. In other words, it is a poor solvent for the polymer formed by polymerization of the vinyl monomer. . 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, examples of the organic solvent include methanol, ethanol, propanol, butanol, Alcohols such as hexanol, cyclohexanol, octanol, II-ethylhexanol, decanol, dodecanol, ethylene glycol, propylene glycol, tetramethylene glycol, glycerin; diethyl ether, ethylene glycol dimethyl ether, cellosolve, methyl cellosolve, butyl cellosolve, polyethylene glycol, polypropylene Chain (poly) ethers such as glycol and polytetramethylene glycol; hexane, heptane, octane, isooctane, decane, dope Examples include chain saturated hydrocarbons such as decane; esters such as ethyl acetate, isopropyl acetate, cellosolve acetate, and ethyl propionate. 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 30 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 30% by weight, the polymerization rate is lowered, or the monolith structure after polymerization deviates from the range of the present invention. 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, potassium persulfate, ammonium persulfate, tetramethylthiuram disulfide and the like. The amount of the 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 crosslinking agent.

  In step III, the mixture obtained in step II is allowed to stand and polymerize in the presence of the monolith intermediate obtained in step I to obtain a thick monolith having a skeleton thicker than the skeleton of the monolith intermediate. It is a process to obtain. 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 crosslinking agent are allowed to stand in a specific organic solvent in the absence of a monolith intermediate, a particle aggregation type monolithic organic porous material is obtained. The 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 above-mentioned thick monolith is lost. Is obtained. The reason for this has not been elucidated in detail, but in the absence of a monolith intermediate, the cross-linked polymer produced by polymerization precipitates and precipitates in the form of particles, while a particle aggregate structure is formed. When a porous body (intermediate) is present in the system, the vinyl monomer and the cross-linking agent are adsorbed or distributed from the liquid phase to the skeleton of the porous body, and polymerization proceeds in the porous body to obtain a thick skeleton monolith. It is thought that. Although the opening diameter is narrowed by the progress of the polymerization, since the total pore volume of the monolith intermediate is large, an appropriate opening diameter can be obtained even if the skeleton becomes thick.

  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 thick monolith after polymerization is not pressed from the inner wall of the container and enters the reaction container without any gap, and 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 thick 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, potassium persulfate, etc. are used as initiators In a sealed container under an inert atmosphere, heat polymerization may be performed at 30 to 100 ° C. for 1 to 48 hours. By heat polymerization, the vinyl monomer adsorbed and distributed on the skeleton of the monolith intermediate and the cross-linking agent are polymerized in the skeleton to thicken the skeleton. After completion of the polymerization, the contents are taken out and extracted with a solvent such as acetone for the purpose of removing unreacted vinyl monomer and organic solvent to obtain a thick monolith.

  Next, a method of introducing an ion exchange group after producing a monolith by the above method is preferable in that the porous structure of the resulting monolith ion exchanger can be strictly controlled.

There is no restriction | limiting in particular as a method to introduce | transduce an ion exchange group into the said monolith, Well-known methods, such as a polymer reaction and graft polymerization, can be used. For example, as a method of introducing a sulfonic acid group, if the monolith is a styrene-divinylbenzene copolymer, etc., a method of sulfonation using chlorosulfuric acid, concentrated sulfuric acid or fuming sulfuric acid; A method of grafting a sodium styrenesulfonate or acrylamido-2-methylpropanesulfonic acid by introducing a mobile group into the skeleton surface or inside the skeleton; Similarly, after graft polymerization of glycidyl methacrylate, a sulfonic acid group is introduced by functional group conversion. And the like. As a method for introducing a quaternary ammonium group, if the monolith is a styrene-divinylbenzene copolymer or the like, a method of introducing a chloromethyl group with chloromethyl methyl ether or the like and then reacting with a tertiary amine; A method in which chloromethylstyrene and divinylbenzene are produced by copolymerization and reacted with a tertiary amine; N, N, N-trimethylammonium is introduced into the monolith by introducing radical initiation groups and chain transfer groups uniformly into the skeleton surface and inside the skeleton. Examples include a method of graft polymerization of ethyl acrylate and N, N, N-trimethylammoniumpropylacrylamide; a method of grafting glycidyl methacrylate in the same manner and then introducing a quaternary ammonium group by functional group conversion. Examples of the method for introducing betaine include a method in which a tertiary amine is introduced into a monolith by the above method and then introduced by reacting with monoiodoacetic acid. Among these methods, the method of introducing a sulfonic acid group includes a method of introducing a sulfonic acid group into a styrene-divinylbenzene copolymer using chlorosulfuric acid, and a method of introducing a quaternary ammonium group includes styrene. -Introducing a chloromethyl group into the divinylbenzene copolymer with chloromethyl methyl ether, etc., then reacting with a tertiary amine, or producing a monolith by copolymerization of chloromethylstyrene and divinylbenzene and reacting with a tertiary amine The method is preferable in that the ion exchange group can be introduced uniformly and quantitatively. The 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 ester groups; quaternary ammonium groups, tertiary amino groups, and secondary amino groups. Groups, primary amino groups, polyethyleneimine groups, tertiary sulfonium groups, phosphonium groups and the like.

  Since the cation exchange group is introduced into the thick monolith, the first monolith ion exchanger swells greatly, for example, 1.4 to 1.9 times as thick as the monolith. That is, the degree of swelling is much greater than that obtained by introducing an ion exchange group into a conventional monolith described in JP-A-2002-306976. For this reason, even if the opening diameter of the thick monolith is small, the opening diameter of the monolith ion exchanger generally increases at the above magnification. In addition, the total pore volume does not change even when the opening diameter increases due to swelling. Therefore, the first monolith ion exchanger has a high mechanical strength because it has a thick bone skeleton despite the remarkably large opening diameter.

<Description of Second Monolith Ion Exchanger>
The second monolith ion exchanger is a tertiary having a thickness of 1 to 60 μm made of an aromatic vinyl polymer containing 0.3 to 5.0 mol% of a crosslinked structural unit among all the structural units into which ion exchange groups are introduced. A co-continuous structure comprising an originally continuous skeleton and three-dimensionally continuous pores having a diameter of 10 to 100 μm between the skeletons, and the total pore volume is 0.5 to 5 ml / g Yes, the ion exchange capacity per volume in a water-wet state is 0.3 to 5 mg equivalent / ml, and the ion exchange groups are uniformly distributed in the porous ion exchanger.

  The second monolith ion exchanger has a three-dimensional continuous skeleton having an average thickness of 1 to 60 μm, preferably 3 to 58 μm in a water-wet state in which ion-exchange groups are introduced, and an average diameter between the skeletons. It is a co-continuous structure composed of three-dimensionally continuous pores of 10 to 100 μm, preferably 15 to 90 μm, particularly 20 to 80 μm in a wet state. That is, as shown in the schematic diagram of FIG. 6, the co-continuous structure is a structure 10 in which a continuous skeleton phase 1 and a continuous vacancy phase 2 are intertwined and each of them is three-dimensionally continuous. The continuous pores 2 have higher continuity of the pores than the conventional open-cell monolith and particle aggregation type monolith, and the size thereof is not biased. Therefore, it is possible to achieve extremely uniform ion adsorption behavior. Moreover, since the skeleton is thick, the mechanical strength is high.

  The skeleton thickness and pore diameter of the second monolith ion exchanger are larger than the monolith skeleton thickness and pore diameter because the entire monolith swells when an ion exchange group is introduced into the monolith. It becomes. These continuous pores have higher continuity of pores and are not biased in size compared to conventional open-cell monolithic organic porous ion exchangers and particle-aggregated monolithic organic porous ion exchangers. Therefore, extremely uniform ion adsorption behavior can be achieved. If the diameter of the three-dimensionally continuous pores is less than 10 μm, the pressure loss when passing through the fluid increases, which is not preferable. As a result, the ion exchange characteristics are not uniform, that is, the length of the ion exchange zone becomes long, or a small amount of adsorbed ions are likely to leak, which is not preferable. In addition, if the thickness of the skeleton is less than 1 μm, it is not preferable because the ion exchange capacity per volume decreases and the mechanical strength decreases, which is not preferable. On the other hand, if the skeleton thickness is too large, Since the uniformity of the exchange characteristics is lost and the ion exchange zone length becomes long, it is not preferable.

  The average diameter of the pores of the above-mentioned continuous structure in the water wet state is a value calculated by multiplying the average diameter of the pores of the monolith ion exchanger in the dry state measured by a known mercury intrusion method and the swelling ratio. It is. Specifically, the water-wet monolith ion exchanger has a diameter of x2 (mm), and the water-wet monolith ion exchanger is dried, and the resulting dried monolith ion exchanger has a diameter of y2 ( mm), and the average diameter of the pores when the dried monolith ion exchanger was measured by the mercury intrusion method was z2 (μm), the pores of the monolith ion exchanger in the water-wet state The average diameter (μm) is calculated by the following formula: “average diameter (μm) of water holes in the monolith ion exchanger pores = z2 × (x2 / y2)”. In addition, the average diameter of the pores of the dried monolith before introduction of the ion exchange groups, and the swelling ratio of the water-dried monolith ion exchanger with respect to the dried monolith when the ion exchange groups are introduced into the dried monolith. If it is known, the average diameter of the monolith ion exchanger pores in the water-wet state can be calculated by multiplying the average diameter of the pores of the dry monolith by the swelling rate. Further, the average thickness of the skeleton of the continuous structure in the water-wet state is obtained by performing SEM observation of the dried monolith ion exchanger at least three times, and measuring the thickness of the skeleton in the obtained image. It is a value calculated by multiplying the average value by the swelling rate. Specifically, the water-wet monolith ion exchanger has a diameter of x3 (mm), the water-wet monolith ion exchanger is dried, and the resulting dried monolith ion exchanger has a diameter of y3 ( SEM observation of this dried monolith ion exchanger 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 ion exchanger in the water wet state is expressed by the following formula: “average thickness of the skeleton of the continuous structure of the monolith ion exchanger (μm) = z3 × (X3 / y3) ". In addition, the average thickness of the skeleton of the dried monolith before the introduction of the ion exchange group, and the swelling ratio of the monolith ion exchanger in the water wet state relative to the dried monolith when the ion exchange group is introduced into the dried monolith. When it is understood, the average thickness of the skeleton of the monolith ion exchanger can be calculated by multiplying the average thickness of the skeleton of the monolith in the dry state by the swelling ratio. The skeleton has a rod-like shape and a circular cross-sectional shape, but may have a cross-section with a different diameter such as an elliptical cross-sectional shape. The thickness in this case is the average of the minor axis and the major axis.

  If the thickness of the three-dimensional continuous rod-like skeleton is less than 10 μm, the second monolith ion exchanger is not preferable because the ion exchange capacity per volume is lowered, and if it exceeds 100 μm, the ion exchange characteristics This is not preferable because the uniformity of the film is lost. The definition and measurement method of the wall of the monolith ion exchanger are the same as those of the monolith.

  The second monolith ion exchanger has a total pore volume of 0.5 to 5 ml / g. If the total pore volume is less than 0.5 ml / g, the pressure loss at the time of fluid permeation increases, which is not preferable. Further, the amount of water per unit cross-sectional area decreases, and the processing capacity decreases. It is not preferable. On the other hand, if the total pore volume exceeds 5 ml / g, the ion exchange capacity per volume decreases, which is not preferable. If the three-dimensionally continuous pore size and total pore volume are within the above ranges, the contact with the fluid is extremely uniform and the contact area is large, so the ion exchange zone length is shortened and the adsorbed ions It is difficult to cause a slight leak. In addition, since the fluid can be permeated under a low pressure loss, it exhibits excellent performance as an ion adsorbent. The total pore volume of the monolith (monolith intermediate, monolith, monolith ion exchanger) is the same in the dry state and in the water wet state.

  The pressure loss when water was permeated through the second monolith ion exchanger was the pressure loss when water was passed through a column filled with 1 m of a porous material at a water flow rate (LV) of 1 m / h (hereinafter referred to as “pressure loss”). And “differential pressure coefficient”) in the range of 0.001 to 0.5 MPa / m · LV, particularly 0.001 to 0.1 MPa / m · LV. If the permeation rate and the total pore volume are within this range, when this is used as an ion adsorbent, the contact area with the water to be treated is large and the water to be treated can be smoothly distributed. It is preferable because of its high mechanical strength.

  In the second monolith ion exchanger, the material constituting the skeleton of the co-continuous structure is 0.3 to 5 mol%, preferably 0.5 to 3.0 mol% of the crosslinked structural unit in all the structural units. It is an aromatic vinyl polymer containing and is hydrophobic. If 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 5 mol%, the structure of the porous body tends to deviate from the bicontinuous structure. There is no restriction | limiting in particular in the kind of this aromatic vinyl polymer, For example, a polystyrene, poly ((alpha) -methylstyrene), polyvinyl toluene, polyvinyl benzyl chloride, polyvinyl biphenyl, polyvinyl naphthalene etc. are mentioned. The polymer may be a polymer obtained by copolymerizing a single vinyl monomer and a crosslinking agent, a polymer obtained by polymerizing a plurality of vinyl monomers and a crosslinking agent, or a blend of two or more types of polymers. It may be what was done. Among these organic polymer materials, a styrene-divinylbenzene copolymer is used because of its ease of forming a co-continuous structure, ease of introduction of ion exchange groups, high mechanical strength, and high stability against acids and alkalis. And vinylbenzyl chloride-divinylbenzene copolymer is preferred.

  The second monolith ion exchanger has an ion exchange capacity of 0.3 to 5 mg equivalent / ml cation exchange capacity per volume in a wet state of water. In the conventional monolithic organic porous ion exchanger having a continuous macropore structure different from the present invention as described in JP-A-2002-306976, in order to achieve a low pressure loss that is practically required, When the opening diameter is increased, the total pore volume is increased accordingly, so that the ion exchange capacity per volume is decreased, and the total pore volume is decreased to increase the exchange capacity per volume. In addition, since the opening diameter is reduced, the pressure loss increases. On the other hand, since the monolith ion exchanger of the present invention has high continuity and uniformity of three-dimensionally continuous pores, the pressure loss does not increase so much even if the total pore volume is reduced. Therefore, the ion exchange capacity per volume can be dramatically increased while keeping the pressure loss low, and the replacement frequency of the module can be reduced. The ion exchange capacity per weight in the dry state of the second monolith ion exchanger is not particularly limited, but the ion exchange groups are uniformly introduced to the skeleton surface and the skeleton inside the porous body. 5 mg equivalent / g. The ion exchange capacity of a porous body in which ion exchange groups are introduced only on the surface of the skeleton cannot be determined unconditionally depending on the kind of the porous body or ion exchange groups, but is at most 500 μg equivalent / g.

  The ion exchange group in the second monolith ion exchanger is the same as the ion exchange group in the first monolith ion exchanger, and the description thereof is omitted. In the second monolith ion exchanger, the introduced ion exchange groups are uniformly distributed not only on the surface of the porous body but also inside the skeleton of the porous body. The definition of the uniform distribution is the same as the definition of the uniform distribution of the first monolith ion exchanger.

(Method for producing second monolith ion exchanger)
The second monolith ion exchanger prepares a water-in-oil emulsion by stirring a mixture of oil-soluble monomer, surfactant and water that does not contain ion-exchange groups, and then polymerizes the water-in-oil emulsion. Step I for obtaining a monolithic organic porous intermediate having a continuous macropore structure having a total pore volume of more than 16 ml / g and 30 ml / g or less, an aromatic vinyl monomer, and at least two or more vinyl groups in one molecule From an organic solvent and a polymerization initiator in which 0.3 to 5 mol% of the cross-linking agent, aromatic vinyl monomer and cross-linking agent dissolve but the polymer formed by polymerization of the aromatic vinyl monomer does not dissolve in the total oil-soluble monomer having Step II for preparing the mixture, 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. III to obtain a continuous structure, obtained by performing the IV step of introducing ion exchange groups to resulting co-continuous structure in the step III.

  What is necessary is just to perform the I process of obtaining the monolith intermediate body in a 2nd monolith ion exchanger based on the method of Unexamined-Japanese-Patent No. 2002-306976.

  That is, in the step I, as the oil-soluble monomer not containing an ion exchange group, for example, it 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, and is lipophilic. These monomers are mentioned. Specific examples of these 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; butadiene Diene monomers such as vinyl chloride, vinyl bromide, vinylidene chloride and tetrafluoroethylene; nitrile monomers such as acrylonitrile and methacrylonitrile; vinyl esters such as vinyl acetate and vinyl propionate Methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethyl methacrylate Sill, cyclohexyl methacrylate, benzyl methacrylate, and (meth) acrylic monomer of glycidyl methacrylate. Among these monomers, preferred are aromatic vinyl monomers such as styrene, α-methylstyrene, vinyl toluene, vinyl benzyl chloride, divinyl benzene and the like. These monomers can be used alone or in combination of two or more. However, a crosslinkable monomer such as divinylbenzene or ethylene glycol dimethacrylate is selected as at least one component of the oil-soluble monomer, and its content is 0.3 to 5 mol%, preferably 0.3 to the total oil-soluble monomer. 3 mol% is preferable in that a mechanical strength necessary for introducing a large amount of ion-exchange groups in a later step can be obtained.

  The surfactant is the same as the surfactant used in step I of the first monolith ion exchanger, and the description thereof is omitted.

  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, tetramethylthiuram disulfide, hydrogen peroxide-ferrous chloride Sodium persulfate-sodium acid sodium sulfite and the like.

  As a mixing method when an oil-soluble monomer not containing an ion exchange group, a surfactant, water and a polymerization initiator are mixed to form a water-in-oil emulsion, in the step I of the first monolith ion exchanger This is the same as the mixing method, and the description thereof is omitted.

  In the second method for producing a monolith ion exchanger, the monolith intermediate obtained in the step I is an organic polymer material having a crosslinked structure, preferably an aromatic vinyl polymer. Although the crosslinking density of the polymer material is not particularly limited, it contains 0.3 to 5 mol%, preferably 0.3 to 3 mol% of crosslinked structural units with respect to all 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 5 mol%, the structure of the monolith tends to deviate from the co-continuous structure, which is not preferable. In particular, when the total pore volume is as small as 16 to 20 ml / g in the present invention, the cross-linking structural unit is preferably less than 3 mol in order to form a co-continuous structure.

  The type of the polymer material of the monolith intermediate is the same as the type of the polymer material of the monolith intermediate of the first monolith ion exchanger, and the description thereof is omitted.

  The total pore volume of the monolith intermediate is more than 16 ml / g and not more than 30 ml / g, preferably 6-25 ml / g. In other words, this monolith intermediate basically has a continuous macropore structure, but the opening (mesopore) that is the overlapping part of the macropore and the macropore is remarkably large. It has a structure as close as possible to the original rod-like skeleton. When this coexists in the polymerization system, a porous body having a co-continuous structure is formed using the structure of the monolith intermediate as a template. If the total pore volume is too small, the structure of the monolith obtained after polymerizing the vinyl monomer is not preferable because it changes from a co-continuous structure to a continuous macropore structure. On the other hand, if the total pore volume is too large, This is not preferable because the mechanical strength of the monolith obtained after polymerizing the vinyl monomer is lowered and the ion exchange capacity per volume is lowered. In order to make the total pore volume of the monolith intermediate within a specific range of the second monolith ion exchanger, the ratio of monomer to water may be approximately 1:20 to 1:40.

  Moreover, the average diameter of the opening (mesopore) which is an overlap part of a macropore and a macropore is a monolith intermediate body is 5-100 micrometers in a dry state. If the average diameter of the openings is less than 5 μm, the opening diameter of the monolith obtained after polymerizing the vinyl monomer becomes small, and the pressure loss during water passage 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 the contact between the water to be treated and the monolith ion exchanger becomes insufficient, resulting in adsorption characteristics and ion exchange. This is not preferable because the characteristics deteriorate. 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.

  In the second method for producing a monolithic ion exchanger, the step II includes 0.3 to 5 mol% of a crosslinking agent in the aromatic vinyl monomer and the total oil-soluble monomer having at least two or more vinyl groups in one molecule. This is a step of preparing a mixture comprising an organic solvent and a polymerization initiator that dissolves the aromatic vinyl monomer and the crosslinking agent but does not dissolve the polymer formed by polymerization of the aromatic vinyl monomer. 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.

  In the second method for producing a monolithic ion exchanger, the aromatic vinyl monomer used in step II includes a lipophilic aromatic vinyl monomer that contains a polymerizable vinyl group in the molecule and has high solubility in an organic solvent. If it is, there is no particular limitation, but it is preferable to select a vinyl monomer that produces the same or similar polymer material as the monolith intermediate coexisting in the polymerization system. Specific examples of these vinyl monomers include styrene, α-methylstyrene, vinyl toluene, vinyl benzyl chloride, vinyl biphenyl, vinyl naphthalene and the like. These monomers can be used alone or in combination of two or more. Aromatic vinyl monomers preferably used in the present invention are styrene, vinyl benzyl chloride and the like.

  The amount of these aromatic vinyl monomers added is 5 to 50 times, preferably 5 to 40 times, by weight with respect to the monolith intermediate coexisting during polymerization. If the amount of aromatic vinyl monomer added is less than 5 times that of the porous material, the rod-like skeleton cannot be thickened, the ion exchange capacity per volume after the introduction of ion exchange groups is reduced, and excellent ion exchange capacity is obtained. Cannot be demonstrated.

  As the crosslinking agent used in step II, a crosslinking agent containing at least two polymerizable vinyl groups in the molecule and having high solubility in an organic solvent is preferably used. Specific examples of the crosslinking agent include divinylbenzene, divinylnaphthalene, divinylbiphenyl, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, butanediol diacrylate, and the like. These crosslinking agents can be used singly or in combination of two or more. Preferred cross-linking agents are aromatic polyvinyl compounds such as divinylbenzene, divinylnaphthalene and divinylbiphenyl because of their high mechanical strength and stability to hydrolysis. The amount of the crosslinking agent used is 0.3 to 5 mol%, particularly 0.3 to 3 mol%, based on the total amount of vinyl monomer and crosslinking agent (total oil-soluble monomer). 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. This is not preferable because a problem arises in that the amount of introduction of is reduced. In addition, it is preferable to use the said crosslinking agent usage-amount so that it may become substantially equal to the crosslinking density of the monolith intermediate body coexisted at the time of vinyl monomer / crosslinking agent polymerization. If the amounts used of both are too large, the crosslink density distribution is biased in the produced monolith, and cracks are likely to occur during the ion exchange group introduction reaction.

  The organic solvent used in step II is an organic solvent that dissolves the aromatic vinyl monomer and the crosslinking agent but does not dissolve the polymer formed by polymerization of the aromatic vinyl monomer, in other words, is formed by polymerization of the aromatic vinyl monomer. It is a poor solvent for polymers. Since the organic solvent varies greatly depending on the type of the aromatic vinyl monomer, it is difficult to list general specific examples. For example, when the aromatic vinyl monomer is styrene, the organic solvent includes methanol, ethanol, Alcohols such as propanol, butanol, hexanol, cyclohexanol, octanol, 2-ethylhexanol, decanol, dodecanol, propylene glycol, tetramethylene glycol; chain structures such as diethyl ether, butyl cellosolve, polyethylene glycol, polypropylene glycol, polytetramethylene glycol (Poly) ethers; chain saturated hydrocarbons such as hexane, heptane, octane, isooctane, decane, dodecane; ethyl acetate, isopropyl acetate, cellosolve acetate, propionic acid Examples include esters such as ethyl. 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 aromatic vinyl monomer is 30 to 80% by weight. If the amount of the organic solvent used deviates from the above range and the aromatic vinyl monomer concentration becomes less than 30% by weight, the polymerization rate is lowered, or the monolith structure after polymerization deviates from the scope of the present invention, which is not preferable. On the other hand, if the concentration of the aromatic vinyl monomer exceeds 80% by weight, the polymerization may run away, which is not preferable.

  The polymerization initiator is the same as the polymerization initiator used in Step II of the first monolith ion exchanger, and the description thereof is omitted.

  In the second method for producing a monolith ion exchanger, in step III, the mixture obtained in step II is allowed to stand and polymerize in the presence of the monolith intermediate obtained in step I. This is a process of changing the continuous macropore structure of the body to a co-continuous structure to obtain a monolith with a bone skeleton. 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 crosslinking agent are allowed to stand in a specific organic solvent in the absence of a monolith intermediate, a particle aggregation type monolithic organic porous material is obtained. The body is obtained. On the other hand, when a monolith intermediate having a specific continuous macropore structure is present in the polymerization system as in the second monolith of the present invention, the structure of the monolith after the polymerization changes dramatically and the particle aggregation structure disappears. Thus, a monolith having the above-described bicontinuous structure is obtained. The reason for this has not been elucidated in detail, but in the absence of a monolith intermediate, the cross-linked polymer produced by polymerization precipitates and precipitates in the form of particles, while a particle aggregate structure is formed. When a porous body (intermediate) having a large total pore volume is present in the system, the vinyl monomer and the crosslinking agent are adsorbed or distributed from the liquid phase to the skeleton of the porous body, and polymerization proceeds in the porous body. It is considered that the skeleton constituting the monolith structure is changed from a two-dimensional wall surface to a one-dimensional rod-like skeleton to form a monolithic organic porous body having a co-continuous structure.

  The internal volume of the reaction vessel is the same as the description of the internal volume of the reaction vessel of the first monolith ion exchanger, and the description thereof is omitted.

  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 5 to 50 times, preferably 5 to 40 times, by weight of the aromatic vinyl monomer added to the monolith intermediate. It is preferable to blend them as described above. Thereby, it is possible to obtain a monolith having a co-continuous structure in which pores of an appropriate size are three-dimensionally continuous and a thick skeleton is three-dimensionally continuous. In the reaction vessel, the aromatic vinyl monomer and the cross-linking agent in the mixture are adsorbed and distributed on the skeleton of the monolith intermediate that is allowed to stand, and polymerization proceeds in the skeleton of the monolith intermediate.

  The basic structure of a monolith having a co-continuous structure is a three-dimensional continuous skeleton having an average thickness of 0.8 to 40 μm in a dry state and a three-dimensional continuous sky having a diameter of 8 to 80 μm between the skeletons. This is a structure in which holes are arranged. The average diameter of the three-dimensionally continuous pores can be obtained as a maximum value of the pore distribution curve by measuring the pore distribution curve by the mercury intrusion method. The thickness of the skeleton of the monolith may be calculated by performing SEM observation at least three times and measuring the average thickness of the skeleton in the obtained image. A monolith having a co-continuous structure has a total pore volume of 0.5 to 5 ml / g.

  The polymerization conditions are the same as the description of the polymerization conditions in step III of the first monolith ion exchanger, and the description thereof is omitted.

  In the step IV, the method for introducing an ion exchange group into a monolith having a co-continuous structure is the same as the method for introducing an ion exchange group into a monolith in the first monolith ion exchanger, and the description thereof is omitted.

  Since the ion exchange group is introduced into the bilithic monolith, the second monolith ion exchanger swells greatly, for example, 1.4 to 1.9 times that of the monolith. Further, the total pore volume does not change even if the pore diameter becomes larger due to swelling. Therefore, the second monolith ion exchanger has a high mechanical strength because it has a thick bone skeleton even though the size of three-dimensionally continuous pores is remarkably large. In addition, since the skeleton is thick, it is possible to increase the ion exchange capacity per volume in a wet state of water, and it is possible to pass water to be treated for a long time at a low pressure and a large flow rate. be able to.

  An ion adsorption module according to an embodiment of the present invention includes a container having at least an opening through which water to be treated flows, and a first monolith ion exchanger or a second monolith ion exchanger filled in the container. It is. As long as this container has only an opening through which water to be treated flows, it can be applied to a batch processing method in which the ion adsorption module is put into water in a storage container or storage tank to purify the water. As long as it has a treated water inflow pipe into which treated water flows and a treated water outflow pipe from which treated water flows out, it can be applied to a continuous water treatment method that has been generally used. The contact form of the water to be treated and the ion adsorption module is not particularly limited as long as the water to be treated and the porous ion exchanger are brought into contact with each other, and it rises to a simple cylindrical or polygonal packed bed. A method of passing water in a flow or downward flow, an external pressure method in which a cylindrical packed bed is passed from the outer circumferential direction to the inner cylinder, an internal pressure method in which water is passed in the reverse direction, a large number of cylindrical organic porous bodies are filled, Examples thereof include a tubular method that allows water to flow by a pressure method or an external pressure method, a flat membrane method that uses a sheet-like packed bed, and a pleat method that forms a flat membrane into a folded shape.

  Further, as the shape of the porous ion exchanger to be filled, a block shape, a sheet shape, a plate shape, a columnar shape, a cylindrical shape, or the like is selected according to the shape of the container of the module taking the adsorption form. Further, the organic porous ion exchanger may be formed into a spherical or irregular granular small block of 0.1 mm to 10 mm, and this small block may be filled into a container to form a packed bed. As a method for molding these various shapes of porous ion exchangers, a method by cutting from a block-shaped porous ion exchanger, or a method in which the emulsion is filled in a mold of a desired shape and polymerization is performed in the mold Etc.

  The type and form of the porous ion exchanger filled in the container are not particularly limited, and can be arbitrarily determined depending on the purpose of use and the type of ionic impurities to be adsorbed. Specifically, a form in which the container is filled with a porous cation exchanger or a porous anion exchanger alone or in combination is exemplified. In addition, as a form to mix the porous ion exchanger, a form formed or processed into a block shape, a sheet shape, a plate shape or a column shape is laminated with respect to the water flow direction, or a small block ion exchanger is mixed. And filling form. Among these, a porous cation exchanger and a porous anion exchanger that are stacked and filled are preferred in terms of easy production of the porous ion exchanger and filling of the container.

  As another form of the ion exchange module of the present invention, a granular ion exchange resin packed layer and the porous ion exchanger packed layer are laminated in this order from the upstream side, and the porous ion What arrange | positions the ion adsorption module with which the exchanger was filled in the downstream of the ion adsorption module with which the granular ion exchange resin was filled is mentioned. The former form can omit connection piping compared with the latter form. By placing the granular ion exchange resin, which has been widely used in the past, in the upstream part and the porous ion exchanger in the downstream part, a large amount of ionic impurities are removed first, and then the residual ionic impurities are efficiently removed. By removing, the total ion exchange zone length can be reduced, the volume of the ion adsorption tower can be reduced, and the adsorption efficiency at a high flow rate can be improved. The upstream granular ion exchange resin is preferably a mixed ion exchange resin of a cation exchange resin and an anion exchange resin, and the downstream porous ion exchanger is preferably a stacked packed layer of a porous cation exchanger and a porous anion exchanger. .

  The shape of the ion exchange module used in the present invention is not particularly limited, and examples thereof include a column shape, a flat shape, and a tower shape having an end plate portion at a lower portion. A flat (small drum-shaped) ion exchange module is a water treatment method in which the ion exchanger packed layer is short in the direction of water flow and long in the direction (diameter) perpendicular to the direction of water flow, and water flow and regeneration are performed in a short time. Suitable for. In addition, a so-called ion exchange tower having a mirror plate part in the lower part is used in the case of stacking and filling the granular ion exchange resin and the porous ion exchanger in the other embodiment. In other words, a so-called ion exchange tower having a mirror plate part in a conventional lower part has a desalting part filled with a granular ion exchange resin from the upstream side to the downstream side, and a pumice stone serving as the eyeplate or distributor. In the case of the ion exchange module in this example, the porous ion exchanger is filled with the end plate or pumice (tecapore) of the end plate part. This increases the efficiency of adsorption of ionic impurities in a high-speed flow, and the porous ion exchanger serves as a distributor, so that the number of parts in the tower can be reduced. Reproduction efficiency is improved without moving. In addition, according to the ion adsorption module of the present invention, the porous ion exchanger can be obtained, for example, in the form of a block that fits into a filling container, and is easily filled.

  The water treatment method of the present invention comprises a method of adsorbing and removing ionic impurities in the water to be treated by bringing the water to be treated into contact with the porous ion exchanger (first method of water treatment), and the water to be treated and granular. This is a method (second water treatment method) in which a second treated water is obtained by further contacting the first treated water obtained by contacting the ion exchange resin with the porous ion exchanger. In the first water treatment method, when treating water to be treated having a small amount of ionic impurities, for example, conductivity of 0.1 to 100 mS / m in the water to be treated, the porous ion exchanger is filled. It is suitable for a water treatment method that uses an easy and small apparatus and regenerates frequently. Further, the ion exchange zone length can be kept short even at a high flow rate, and the volume of the ion exchanger apparatus can be reduced. According to the second water treatment method, the adsorption rate is high even if the amount of ionic impurities is very small, and the leak of adsorbed ions hardly occurs. That is, since the granular ion exchange resin has a particle size of 0.2 to 0.5 mm, the diffusion rate inside and outside the particle is greatly different, and when the flow rate is increased, the ion is a mixed region of the ion adsorbing part and the non-adsorbing part. Although the exchange zone length becomes long and a slight leak of adsorbed ions occurs, the total exchange capacity is large, so that rough ion removal is possible. On the other hand, since the organic porous ion exchanger having a three-dimensional network structure has a small total exchange capacity but does not spread in the diffusion rate, the ion exchange zone length can be kept short even at a high flow rate. For this reason, by installing the granular ion exchange resin on the upstream side and the organic porous ion exchanger on the downstream side, first, a large amount of ionic substances are removed, and then residual ions are removed with high efficiency. It is possible to reduce the total ion exchange zone length, reduce the volume of the ion adsorption tower, and improve the adsorption efficiency at a high flow rate. Therefore, the ion adsorption module can be used as an alternative to a cartridge polisher used in a subsystem of a conventional ultrapure water production apparatus, for example.

  In the water treatment method of the present invention, the porous ion exchanger is made into an ion form having a lower adsorption selectivity than the removal target ions in the water to be treated, and then the water to be treated is passed, A method may be used in which the ions having low adsorption selectivity are released into the water to be treated while being removed by adsorption. Specifically, when the ions to be removed are calcium ions and magnesium ions, sodium ions having a lower selective adsorptivity are adsorbed on the porous ion exchanger and used for water treatment. This method is preferable in that it is not necessarily required to remove all the ions when scale prevention is the main purpose of water treatment, such as boiler feed water, and it can be safely and inexpensively regenerated. Further, in the water treatment method of the present invention, the porous ion exchanger is a cation exchanger, and after the cation exchanger is made into a sodium form, the water to be treated is passed through, and the hardness component in the water to be treated May be a softening treatment method in which is replaced with sodium. According to this method, the hardness component in the for-treatment water can be easily removed.

  Since the porous ion exchanger used in the ion exchange module and water treatment method of the present invention is repeatedly used for the ion adsorption removal treatment, it can be regenerated with a chemical. Examples of the regeneration treatment method include a method in which an ionic substance adsorbed on the porous ion exchanger is desorbed by contacting an acid and a porous cation exchanger, or an alkali and a porous anion exchanger, respectively. . Examples of the acid include hydrochloric acid, sulfuric acid, and nitric acid, and examples of the alkali include caustic soda. Further, the method of contacting the drug with the porous ion exchanger is not particularly limited to the upward flow or the downward flow. Even when other ion exchangers such as a granular ion exchange resin are mixed, each ion exchanger is Separation is not necessary.

(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.

<Production of first monolithic ion exchanger (Reference Example 1)>
(Step I; production of monolith intermediate)
19.2 g of styrene, 1.0 g of divinylbenzene, 1.0 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 containing 1.8 ml of THF, and a vacuum stirring defoaming mixer which is a planetary stirring device. (EM Co., Ltd.) was used and stirred 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 56 μm, and the total pore volume was 7.5 ml / g.

(Manufacture of monoliths)
Next, 49.0 g of styrene, 1.0 g of divinylbenzene, 50 g of 1-decanol, and 0.5 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were mixed and dissolved uniformly (step II). 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 7.6 g was collected. The separated monolith intermediate is put in a reaction vessel having an inner diameter of 90 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).

  FIG. 1 shows the result of observing the internal structure of the monolith (dry body) containing 1.3 mol% of the crosslinking component composed of the styrene / divinylbenzene copolymer obtained by SEM as described above. The SEM image in FIG. 1 is an image at an arbitrary position on a cut surface obtained by cutting a monolith at an arbitrary position. As is clear from FIG. 1, the monolith has a continuous macropore structure, and the skeleton constituting the continuous macropore structure is much thicker than that of the comparative example of FIG. The thickness of the part was thick.

  Next, the thickness of the wall part and the area of the skeleton part appearing in the cross section were measured from two SEM images obtained by cutting the obtained monolith at a position different from the above position, excluding subjectivity. The wall thickness was an average of 8 points obtained from one SEM photograph, and the skeleton area was determined by image analysis. The wall portion has the above definition. Moreover, the skeleton part area was shown by the average of three SEM images. As a result, the average thickness of the wall portion was 30 μm, and the area of the skeleton portion represented by the cross section was 28% in the SEM image. Moreover, the average diameter of the opening of the monolith measured by mercury porosimetry was 31 μm, and the total pore volume was 2.2 ml / g. The results are summarized in Tables 1 and 2. In Table 1, the preparation column shows, in order from the left, the vinyl monomer used in Step II, the crosslinking agent, the monolith intermediate obtained in Step I, and the organic solvent used in Step II.

(Production of monolith cation exchanger)
The 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 27 g. To this, 1500 ml of dichloromethane was added and heated at 35 ° C. for 1 hour, then cooled to 10 ° C. or lower, 145 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 monolith cation exchanger having a continuous macropore structure.

  The swelling rate before and after the reaction of the obtained cation exchanger was 1.7 times, and the ion exchange capacity per volume was 0.67 mg equivalent / ml in a water wet state. The average diameter of the opening of the organic porous ion exchanger in the water-wet state was estimated to be 54 μm from the value of the organic porous body and the swelling ratio of the cation exchanger in the water-wet state. The average thickness of the wall part constituting the skeleton was 50 μm, the skeleton part area was 28% in the photographic region of the SEM photograph, and the total pore volume was 2.2 ml / g. Moreover, the ion exchange zone length regarding the sodium ion of this monolith cation exchanger was 22 mm in LV = 20 m / h. The differential pressure coefficient, which is an index of pressure loss when water is permeated, was 0.016 MPa / m · LV. The results are summarized in Table 2.

  Next, in order to confirm the distribution state of the sulfonic acid group in the monolith cation exchanger, the distribution state of sulfur atoms was observed by EPMA. The results are shown in FIGS. FIG. 2 shows a distribution state of sulfur atoms on the surface of the cation exchanger, and FIG. 3 shows a distribution state of sulfur atoms in the cross-section (thickness) direction of the cation exchanger. 2 and 3, it can be seen that the sulfonic acid groups are uniformly introduced into the surface of the cation exchanger and inside the skeleton (cross-sectional direction).

<Production of first monolith ion exchanger (Reference Examples 2 to 11)>
(Manufacture of monoliths)
Table 1 shows the amount of styrene used, the type and amount of crosslinking agent, the type and amount of organic solvent, the porous structure of the monolith intermediate coexisting during styrene and divinylbenzene impregnation polymerization, the crosslinking density and the amount used. 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. In addition, from the SEM images (not shown) of Reference Examples 2 to 11 and Table 2, the average diameter of the openings of the monoliths of Reference Examples 2 to 11 is as large as 22 to 70 μm, and the average thickness of the walls constituting the skeleton is also 25 to 25 mm. It was as thick as 50 μm, and the skeletal area was 26-44% in the SEM image area, and it was a monolith of bone.

(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 having a continuous macropore structure. The results are shown in Table 2. The average diameters of the openings of the monolith cation exchangers of Reference Examples 2 to 11 are 46 to 138 μm, the average thickness of the wall portion constituting the skeleton is also as thick as 45 to 110 μm, and the skeleton area is 26 to 44% in the SEM image region. Met. The ion exchange zone length was shorter than the conventional one, and the differential pressure coefficient was also low. The monolith cation exchanger of Reference Example 8 was also evaluated for mechanical properties.

(Mechanical property evaluation of monolith cation exchanger)
The monolith cation exchanger obtained in Reference Example 8 was cut into a strip of 4 mm × 5 mm × 10 mm in a wet state, and used as a test piece for a tensile strength test. The test piece was attached to a tensile tester, the head speed was set to 0.5 mm / min, and the test was performed at 25 ° C. in water. As a result, the tensile strength and the tensile modulus were 45 kPa and 50 kPa, respectively, which were much larger than those of the conventional monolith cation exchanger. Further, the tensile elongation at break was 25%, which was a value larger than that of the conventional monolith cation exchanger.

Reference Examples 12 and 13
(Manufacture of monoliths)
A monolith having the same composition and structure as Reference Example 4 was produced in the same manner as Reference Example 1 except that the amount of styrene used, the amount of crosslinking agent used, and the amount of organic solvent used were changed to the amounts shown in Table 1. . Reference Example 13 was carried out in the same manner as Reference Example 12 except that a reaction vessel having an inner diameter of 110 mm was used instead of the reaction vessel having an inner diameter of 75 mm. The results are shown in Tables 1 and 2.

(Production of monolith anion exchanger)
The 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. To this, 1400 ml of dimethoxymethane and 20 ml of tin tetrachloride were added, and 560 ml of chlorosulfuric acid was added dropwise under ice cooling. After completion of the dropwise addition, the temperature was raised and reacted at 35 ° C. for 5 hours to introduce a chloromethyl group. After completion of the reaction, the mother liquor was extracted with a siphon, washed with a mixed solvent of THF / water = 2/1, and further washed with THF. To this chloromethylated monolithic organic porous material, 1000 ml of THF and 600 ml of a 30% trimethylamine aqueous solution were added and reacted at 60 ° C. for 6 hours. After completion of the reaction, the product was washed with a methanol / water mixed solvent, then washed with pure water and isolated.

  Ion exchange capacity per volume of the anion exchangers of Reference Example 12 and Reference Example 13, average diameter of openings of organic porous ion exchangers in a wet state of water, and walls constituting the skeleton obtained by the same method as that of monolith Table 2 summarizes the average thickness, skeleton area (ratio in the photographic region of the SEM photograph), total pore volume, ion exchange zone length, differential pressure coefficient, and the like.

  Next, in order to confirm the distribution state of the quaternary ammonium groups in the porous anion exchanger, the anion exchanger was treated with an aqueous hydrochloric acid solution to form a chloride form, and then the distribution state of chlorine atoms was observed by EPMA. As a result, it was confirmed that the chlorine atoms were uniformly distributed not only on the skeleton surface of the anion exchanger but also inside the skeleton, and the quaternary ammonium groups were uniformly introduced into the anion exchanger.

<Production of Second Monolith Ion Exchanger (Reference Example 14)>
(Step I; production of monolith intermediate)
5.4 g of styrene, 0.17 g of divinylbenzene, 1.4 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 was added to 180 g of pure water, and a vacuum stirring defoaming mixer (manufactured by EM Co.) as 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. This emulsion was quickly transferred to a reaction vessel and allowed to polymerize at 60 ° C. for 24 hours in a static state after sealing. After completion of the polymerization, the content was taken out, extracted with methanol, and then dried under reduced pressure to produce a monolith intermediate having a continuous macropore structure. When the internal structure of the monolith intermediate (dry body) obtained in this way was observed with an SEM image (FIG. 7), the wall portion separating two adjacent macropores was very thin and rod-shaped, but the open cell structure The average diameter of the openings (mesopores) where the macropores overlap with each other as measured by the mercury intrusion method was 70 μm, and the total pore volume was 21.0 ml / g.

(Manufacture of monocontinuous monolith)
Subsequently, 76.0 g of styrene, 4.0 g of divinylbenzene, 120 g of 1-decanol, and 0.8 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were mixed and dissolved uniformly (step II). Next, the monolith intermediate was cut into a disk shape having a diameter of 70 mm and a thickness of about 40 mm to fractionate 4.1 g. The separated monolith intermediate is placed in a reaction vessel having an inner diameter of 75 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 monolithic contents having a thickness of about 60 mm were taken out, subjected to Soxhlet extraction with acetone, and then dried under reduced pressure at 85 ° C. overnight (step III).

  When the internal structure of the monolith (dry body) containing 3.2 mol% of the crosslinking component composed of the styrene / divinylbenzene copolymer obtained in this way was observed by SEM, the monolith had a skeleton and pores, respectively. It was a three-dimensional continuous structure with both phases intertwined. Moreover, the thickness of the skeleton measured from the SEM image was 10 μm. Further, the size of the three-dimensionally continuous pores of the monolith measured by mercury porosimetry was 17 μm, and the total pore volume was 2.9 ml / g. The results are summarized in Tables 3 and 4. In Table 4, the thickness of the skeleton was represented by the diameter of the skeleton.

(Production of co-continuous monolithic cation exchanger)
The monolith produced by the above method was cut into a disk shape having a diameter of 75 mm and a thickness of about 15 mm. The weight of the monolith was 18 g. To this was added 1500 ml of dichloromethane, heated at 35 ° C. for 1 hour, cooled to 10 ° C. or lower, gradually added 99 g of chlorosulfuric acid, heated up 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 monolith cation exchanger having a co-continuous structure.

  A part of the obtained cation exchanger was cut out and dried, and then its internal structure was observed by SEM. As a result, it was confirmed that the monolith cation body maintained a co-continuous structure. The SEM image is shown in FIG. Moreover, the swelling ratio before and after the reaction of the cation exchanger was 1.4 times, and the ion exchange capacity per volume was 0.74 mg equivalent / ml in a water-wet state. The size of the continuous pores of the monolith in the water wet state was estimated from the value of the monolith and the swelling ratio of the cation exchanger in the water wet state to be 24 μm, the skeleton diameter was 14 μm, and the total pore volume was 2. It was 9 ml / g.

  The differential pressure coefficient, which is an index of pressure loss when water is permeated, was 0.052 MPa / m · LV. Furthermore, when the ion exchange zone length for sodium ions of the monolith cation exchanger was measured, the ion exchange zone length at LV = 20 m / h was 16 mm. Amberlite IR120B (a commercially available strong acid cation exchange resin) It was not only overwhelmingly shorter than the value (320 mm) manufactured by Rohm and Haas, but also shorter than the value of the monolithic porous cation exchanger having a conventional open cell structure. The results are summarized in Table 4.

  Next, in order to confirm the distribution state of the sulfonic acid group in the monolith cation exchanger, the distribution state of sulfur atoms was observed by EPMA. The results are shown in FIGS. 9 and 10, the left and right photographs correspond to each other. FIG. 9 shows a distribution state of sulfur atoms on the surface of the cation exchanger, and FIG. 10 shows a distribution state of sulfur atoms in the cross-section (thickness) direction of the cation exchanger. In the photograph on the left side of FIG. 9, a part extending in a horizontal direction is a skeleton part, and in the photograph on the left side of FIG. 10, two circular shapes are cross sections of the skeleton. 9 and 10, it can be seen that the sulfonic acid groups are uniformly introduced into the surface of the cation exchanger and inside the skeleton (cross-sectional direction).

<Production of Second Monolith Ion Exchanger (Reference Examples 15 to 17)>
(Manufacture of monolith with co-continuous structure)
Except for changing the amount of styrene used, the amount of crosslinking agent used, the amount of organic solvent used, the porous structure of the monolith intermediate coexisting during styrene and divinylbenzene impregnation polymerization, the crosslinking density and the amount used as shown in Table 3. A monolith having a co-continuous structure was produced in the same manner as in Reference Example 14. Reference Example 17 was carried out in the same manner as Reference Example 14 except that a reaction vessel having an inner diameter of 110 mm was used instead of the reaction vessel having an inner diameter of 75 mm. The results are shown in Tables 3 and 4.

(Manufacture of monolith with co-continuous structure)
The amount of styrene used, the amount of crosslinking agent used, the type and amount of organic solvent used, the porous structure of the monolith intermediate coexisting during styrene and divinylbenzene impregnation polymerization, the crosslinking density and the amount used were changed to the amounts shown in Table 4. Except for the above, a monolith having a co-continuous structure was produced in the same manner as in Reference Example 14. The results are shown in Tables 3 and 4.

(Production of monolith cation exchanger having a co-continuous structure)
The monolith produced by the above method was reacted with chlorosulfuric acid in the same manner as in Reference Example 14 to produce a monolith cation exchanger having a co-continuous structure. The results are shown in Table 4. Further, the internal structure of the obtained monolithic cation exchanger having a co-continuous structure is as follows. The monolithic cation exchangers obtained in Reference Examples 15 to 17 from SEM images not shown and Table 4 have a small differential pressure coefficient per volume. Excellent exchange capacity and short ion exchange zone length. The monolith cation exchanger of Reference Example 15 was also evaluated for mechanical properties.

(Mechanical property evaluation of monolith cation exchanger)
The monolith cation exchanger obtained in Reference Example 15 was cut into a strip of 4 mm × 5 mm × 10 mm in a wet state of water and used as a test piece for a tensile strength test. The test piece was attached to a tensile tester, the head speed was set to 0.5 mm / min, and the test was performed at 25 ° C. in water. As a result, the tensile strength and the tensile modulus were 23 kPa and 15 kPa, respectively, which were significantly larger than the conventional monolith cation exchanger. Further, the tensile elongation at break was 50%, which was a value larger than that of the conventional monolith cation exchanger.

Reference Examples 18 and 19
(Manufacture of monolith with co-continuous structure)
Except that the amount of styrene used, the amount of crosslinking agent used, the amount of organic solvent used, the porous structure of the monolith intermediate coexisting during styrene and divinylbenzene impregnation polymerization, the crosslinking density and the amount used were changed to the amounts shown in Table 4. A monolith having a co-continuous structure was produced in the same manner as in Reference Example 14. Reference Example 19 was carried out in the same manner as Reference Example 18 except that a reaction vessel having an inner diameter of 110 mm was used instead of the reaction vessel having an inner diameter of 75 mm. The results are shown in Tables 3 and 4.

(Production of monolith anion exchanger having a co-open cell structure)
The monolith produced by the above method was cut into a disk shape having a diameter of 70 mm and a thickness of about 15 mm. To this, 1400 ml of dimethoxymethane and 20 ml of tin tetrachloride were added, and 560 ml of chlorosulfuric acid was added dropwise under ice cooling. After completion of dropping, the temperature was raised and the reaction was carried out at 35 ° C. for 5 hours to introduce a chloromethyl group. After completion of the reaction, the mother liquor was extracted with a siphon, washed with a mixed solvent of THF / water = 2/1, and further washed with THF. To this chloromethylated monolithic organic porous material, 1000 ml of THF and 600 ml of a 30% trimethylamine aqueous solution were added and reacted at 60 ° C. for 6 hours. After completion of the reaction, the product was washed with a methanol / water mixed solvent, then washed with pure water and isolated.

  The ion exchange capacity per volume of the anion exchangers of Reference Example 18 and Reference Example 19, the average diameter of the continuous pores of the organic porous ion exchanger in a water-wet state, and the thickness of the skeleton obtained by the same method as that of the monolith Table 4 summarizes the total pore volume, ion exchange zone length, differential pressure coefficient, and the like. Moreover, the internal structure of the obtained monolith anion exchanger having a co-continuous structure was observed by an SEM image (not shown).

  Next, in order to confirm the distribution state of the quaternary ammonium groups in the monolith anion exchanger, the anion exchanger was treated with an aqueous hydrochloric acid solution to form a chloride form, and then the distribution state of chlorine atoms was observed by EPMA. As a result, it was confirmed that the chlorine atoms were uniformly distributed not only on the surface of the anion exchanger but also inside, and the quaternary ammonium groups were uniformly introduced into the anion exchanger.

Reference Example 20
(Manufacture of monolithic organic porous material having a continuous macropore structure (known product))
A monolithic organic porous body having a continuous macropore structure was produced according to the production method described in JP-A-2002-306976. That is, 19.2 g of styrene, 1.0 g of divinylbenzene, 1.0 g of 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 monolithic organic porous body having a continuous macropore structure.

  The SEM representing the internal structure of the organic porous material containing 3.3 mol% of the crosslinking component composed of the styrene / divinylbenzene copolymer thus obtained had the same structure as FIG. As is clear from FIG. 12, the organic porous body has a continuous macropore structure, but the thickness of the wall portion constituting the skeleton of the continuous macropore structure is thinner than that of the example, and from the SEM image The measured wall thickness average thickness was 5 μm, and the skeleton area was 10% in the SEM image area. Moreover, the average diameter of the opening of the organic porous material measured by mercury porosimetry was 29 μm, and the total pore volume was 8.6 ml / g. The results are summarized in Table 5. In Tables 1, 2 and 5, the mesopore diameter means the average diameter of the openings. Moreover, in Tables 1-5, the value of thickness, skeleton diameter, and a void | hole each shows an average.

(Production of monolithic organic porous cation exchanger having a continuous macropore structure (known product))
The organic porous body 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 organic porous material was 6 g. To this was added 1000 ml of dichloromethane, and the mixture was heated at 35 ° C. for 1 hour, then cooled to 10 ° C. or less, 30 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 washed with methanol to remove dichloromethane and further washed with pure water to obtain a monolithic porous cation exchanger having a continuous macropore structure. The swelling rate before and after the reaction of the obtained cation exchanger was 1.6 times, and the ion exchange capacity per volume was 0.22 mg equivalent / ml in a water-wet state, which was a small value compared to Reference Example 1 and the like. It was. The average diameter of the mesopores of the organic porous ion exchanger in the water wet state was 46 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 thickness was 8 μm, the skeleton part area was 10% in the SEM image area, and the total pore volume was 8.6 ml / g. The differential pressure coefficient, which is an index of pressure loss when water is permeated, was 0.013 MPa / m · LV. The results are summarized in Table 5. The monolith cation exchanger obtained in Reference Example 20 was also evaluated for mechanical properties.

(Mechanical property evaluation of conventional monolith cation exchanger)
The monolith cation exchanger obtained in Reference Example 20 was subjected to a tensile test by the same method as the evaluation method of Reference Example 8. As a result, the tensile strength and the tensile modulus were 28 kPa and 12 kPa, respectively, which were lower than the monolith cation exchanger of Reference Example 8. The tensile elongation at break was 17%, which was smaller than that of the monolith cation exchanger of the present invention.

Reference Examples 21-23
(Manufacture of monolithic organic porous body having continuous macropore structure)
A monolithic organic porous material having a continuous macropore structure according to the conventional technique in the same manner as in Reference Example 20, except that the amount of styrene used, the amount of divinylbenzene, and the amount of SMO used are changed to the amounts shown in Table 5. The body was manufactured. The results are shown in Table 5. Further, the internal structure of the monolith of Reference Example 23 was observed with an SEM (not shown). In addition, Reference Example 23 is a condition for minimizing the total pore volume, and an opening cannot be formed by adding less water to the oil phase part. In all of the monoliths of Reference Examples 21 to 23, the opening diameter is small as 9 to 18 μm, the average thickness of the wall portion constituting the skeleton is as thin as 15 μm, and the skeleton portion area is as small as 22% at the maximum in the SEM image region. It was.

(Production of monolithic organic porous cation exchanger having a continuous macropore structure)
The organic porous material produced by the above method was reacted with chlorosulfuric acid in the same manner as in Reference Example 20 to produce a monolithic porous cation exchanger having a continuous macropore structure. The results are shown in Table 5. If the opening diameter is increased, the thickness of the wall portion is reduced or the skeleton is reduced. On the other hand, when the wall portion was made thicker or the skeleton was made thicker, the diameter of the opening tended to decrease. As a result, when the differential pressure coefficient was kept low, the ion exchange capacity per volume decreased, and when the ion exchange capacity was increased, the differential pressure coefficient increased.

Reference Example 24
Monolith production was attempted in the same manner as in Reference Example 1, except that the type of organic solvent used in Step II was changed to dioxane, which is a good solvent for polystyrene. However, the isolated product was transparent, suggesting collapse / disappearance of the porous structure. SEM observation was performed for confirmation, but only a dense structure was observed, and the continuous macropore structure disappeared.

Reference Example 25
(Production of porous cation exchanger (known))
27.7 g of styrene, 6.9 g of divinylbenzene, 0.14 g of azobisisobutyronitrile and 3.8 g of sorbitan monooleate were mixed and dissolved uniformly. Next, the styrene / divinylbenzene / azobisisobutyronitrile / sorbitan monooleate mixture is added to 450 ml of pure water, stirred at 20,000 rpm for 2 minutes using a homogenizer, and a water-in-oil emulsion. Got. After emulsification, the water-in-oil emulsion was transferred to a stainless steel autoclave, sufficiently substituted with nitrogen, sealed, and allowed to polymerize at 60 ° C. for 24 hours. After completion of the polymerization, the content was taken out, extracted with Soxhlet for 18 hours with isopropanol, unreacted monomer and sorbitan monooleate were removed, and dried under reduced pressure at 40 ° C. overnight. 5 g of a porous material containing 14 mol% of a crosslinking component composed of a styrene / divinylbenzene copolymer obtained in this manner was collected, 500 g of tetrachloroethane was added, and the mixture was heated at 60 ° C. for 30 minutes, and then to room temperature. After cooling, 25 g of chlorosulfuric acid was gradually added and reacted at room temperature for 24 hours. Thereafter, acetic acid was added, the reaction product was poured into a large amount of water, washed with water and dried to obtain a porous cation exchanger. The ion exchange capacity of this porous material is 4.0 mg equivalent / g in terms of dry porous material, and sulfonic acid groups are uniformly introduced into the porous material by mapping of sulfur atoms using EPMA. It was confirmed. Further, as a result of SEM observation (not shown), the internal structure of the porous body has an open cell structure, and most of the macropores having an average diameter of 30 μm are overlapped, and the mesopores formed by the overlap of the macropores and the macropores. The average diameter was 5 μm and the total pore volume was 10.1 ml / g. The porous body was cut out to a thickness of 10 mm, and the water permeation rate was measured. As a result, it was 14,000 l / min · m ² · MPa.

  In addition, about the monolith ion exchanger manufactured by Reference Examples 1-11 and Reference Examples 20-23, the relationship between a differential pressure coefficient and the ion exchange capacity per volume was shown in FIG. As is clear from FIG. 4, it can be seen that the known reference examples 20 to 23 have a poor balance between the differential pressure coefficient and the ion exchange capacity with respect to the reference examples 1 to 11. On the other hand, it is understood that Reference Examples 1 to 11 have a large ion exchange capacity per volume and a low differential pressure coefficient.

  Raw water was passed through a column having an inner diameter of 57 mm packed with an ion exchanger so as to flow downward from above, and the time during which the sodium concentration in the treated water exceeded 1 μg / l was measured. Moreover, the water flow differential pressure during water flow was also measured. The conditions of this water flow experiment are as follows. As a result, the time when the sodium concentration in the treated water exceeded 1 μg / l was 114 days. The water flow differential pressure was 24 kPa.

(Water flow conditions)
・ Ion exchanger: Mixed resin of granular cation exchange resin and anion exchange resin on the upstream side (mixing ratio = 1: 1 (fill volume ratio), resin layer height: 300 mm) and monolith on the downstream side (diameter 57 mm, height 40 mm) Laminate of cation exchange resin; IR120B (trade name)
・ Anion exchange resin; IRA402BL (trade name)
Raw water: NaCl aqueous solution, sodium concentration 80 μg / l
・ Flow rate: 120 l / h
Monolith; cationic monolith of Reference Example 8

  The cation exchange resin was once made into Na type with sodium chloride, regenerated with 99% regeneration rate with 1N hydrochloric acid, washed thoroughly with ultrapure water and used in a regenerated form. The regeneration rate is the ratio of the H-type capacity among the exchange capacity that can be adsorbed to the resin.

  The same procedure as in Example 1 was performed except that the cation monolith of Reference Example 17 was used instead of the cation monolith of Reference Example 8. As a result, the time when the sodium concentration in the treated water exceeded 1 μg / l was 147 days. Moreover, the water flow differential pressure was 18 kPa.

Comparative Example 1
The same procedure as in Example 1 was performed except that the cation monolith of Reference Example 25 was used instead of the cation monolith of Reference Example 8. As a result, the time during which the sodium concentration in the treated water exceeded 1 μg / l was 21 days. Moreover, the water flow differential pressure was 230 kPa.

Comparative Example 2
The same procedure as in Example 1 was performed except that the ion exchanger was a mixed resin of a granular cation exchange resin and an anion exchange resin (resin layer height: 340 mm). That is, in Comparative Example 1, a monolith is not used as the ion exchanger, and the granular ion exchange resin is 100%. As a result, the time when the sodium concentration in the treated water exceeded 1 μg / l was 0 day, that is, the sodium concentration in the treated water exceeded 1 μg / l from the first day of water flow. Moreover, the water flow differential pressure was 230 kPa.

  In Examples 1 and 2, leakage of adsorbed ions is slower than in Comparative Examples 1 and 2. For this reason, the exchange frequency of an ion exchange module can be reduced. Moreover, since the water flow differential pressure is low, water can be fed at a low pressure.

In Examples 1 and 2, leakage of adsorbed ions is slower than in Comparative Examples 1 and 2. For this reason, the exchange frequency of an ion exchange module can be reduced. Moreover, since the water flow differential pressure is low, water can be fed at a low pressure.
In addition, Example 1 is a reference example.

Claims (10)

  At least a container having an opening through which water to be treated flows and a bubble-shaped macropore filled in the container overlap each other, and this overlapping portion is a continuous macropore structure having an average diameter of 30 to 300 μm in an wet state. The total pore volume is 0.5 to 5 ml / g, the ion exchange capacity per volume in a wet state of water is 0.4 to 5 mg equivalent / ml, and the ion exchange groups are uniformly distributed in the porous ion exchanger. And the SEM image of the cut surface of the continuous macropore structure (dry body) includes an organic porous ion exchanger having a skeleton part area of 25 to 50% in the image region. A featured ion adsorption module.   An aromatic vinyl polymer containing 0.3 to 5.0 mol% of a crosslinked structural unit among all structural units into which at least an opening into which water to be treated flows and an ion exchange group filled in the container are introduced A co-continuous structure comprising a three-dimensionally continuous skeleton having a thickness of 1 to 60 μm and three-dimensionally continuous pores having a diameter of 10 to 100 μm between the skeletons, The volume is 0.5 to 5 ml / g, the ion exchange capacity per volume in a wet state of water is 0.3 to 5 mg equivalent / ml, and the ion exchange groups are uniformly distributed in the porous ion exchanger. An ion adsorption module comprising an organic porous ion exchanger.   The ion adsorption module according to claim 1 or 2, wherein the container includes a treated water inflow pipe connected to an opening into which the treated water flows and a treated water outflow pipe.   The organic porous ion exchanger is an organic porous cation exchanger and an organic porous anion exchanger, and the organic porous cation exchanger and the organic porous anion exchanger are stacked and filled. The ion adsorption module according to any one of claims 1 to 3, wherein A granular ion exchange resin packed bed;
Bubble-shaped macropores overlap each other, and the overlapping portion is a continuous macropore structure having an opening with an average diameter of 30 to 300 μm in a water wet state, the total pore volume is 0.5 to 5 ml / g, and the volume in a water wet state SEM of the cut surface of the continuous macropore structure (dried body) having an ion exchange capacity of 0.4 to 5 mg equivalent / ml, an ion exchange group uniformly distributed in the porous ion exchanger In the image, an ion adsorption module comprising an organic porous ion exchanger packed layer having a skeleton area appearing in a cross section of 25 to 50% in the image region, which is laminated in this order from the upstream side. A granular ion exchange resin packed bed;
A three-dimensionally continuous skeleton having a thickness of 1 to 60 μm composed of an aromatic vinyl polymer containing 0.3 to 5.0 mol% of a crosslinked structural unit among all the structural units having an ion exchange group introduced therein; A co-continuous structure comprising three-dimensionally continuous pores having a diameter of 10 to 100 μm between the skeletons, the total pore volume being 0.5 to 5 ml / g, An organic porous ion exchanger packed layer in which the ion exchange capacity is 0.3 to 5 mg equivalent / ml and the ion exchange groups are uniformly distributed in the porous ion exchanger is laminated in this order from the upstream side. An ion adsorption module characterized by comprising:   The ion adsorption module according to claim 3 or 4, wherein the ion adsorption module is arranged on the downstream side of the ion adsorption module filled with a granular ion exchange resin.   Bubble-shaped macropores overlap each other, and the overlapping portion is a continuous macropore structure having an opening with an average diameter of 30 to 300 μm in a water wet state, the total pore volume is 0.5 to 5 ml / g, and the volume in a water wet state SEM of the cut surface of the continuous macropore structure (dried body) having an ion exchange capacity of 0.4 to 5 mg equivalent / ml, an ion exchange group uniformly distributed in the porous ion exchanger In the image, by adsorbing and removing ionic impurities in the water to be treated by bringing the water to be treated into contact with the organic porous ion exchanger having an area of 25 to 50% in the image area in the image area. A water treatment method characterized.   A three-dimensionally continuous skeleton having a thickness of 1 to 60 μm composed of an aromatic vinyl polymer containing 0.3 to 5.0 mol% of a crosslinked structural unit among all the structural units having an ion exchange group introduced therein; A co-continuous structure comprising three-dimensionally continuous pores having a diameter of 10 to 100 μm between the skeletons, the total pore volume being 0.5 to 5 ml / g, By contacting the water to be treated with an organic porous ion exchanger having an ion exchange capacity of 0.3 to 5 mg equivalent / ml and an ion exchange group uniformly distributed in the porous ion exchanger, A water treatment method comprising adsorbing and removing ionic impurities in water to be treated.   The water treatment method according to claim 8 or 9, wherein the water to be treated is treated water previously treated with a granular ion exchange resin.