JP2009127039A - Monolithic organic porous body, its production method and monolithic organic porous ion exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monolithic organic porous body which has a low pressure loss when a fluid is permeated therethrough and which can be used as an adsorbent having large adsorption capacity or an ion exchanger having large ion exchange capacity, a method for producing the monolithic organic porous body, and a monolithic organic porous ion exchanger. <P>SOLUTION: The monolithic organic porous body is composed of: a skeleton part having such a continuous macropore structure that bubble-shaped macropores are superposed on one another and openings are formed in the superposed portions; and spherical particles which are dispersed in the monolithic organic porous body, are not integrated with the skeleton part and have 0.1-50 μm particle radius. The monolithic organic porous body has 1-5 mL/g total pore volume and ≥5 mm thickness. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a monolithic organic porous material useful as an ion exchanger used in an adsorbent, a deionized water production apparatus, and the like, a production method thereof, and a monolithic organic porous ion exchanger.

  As the structure of the organic porous body, those having an open cell structure (continuous macropore) structure, a bicontinuous structure, and a particle aggregation type structure are known. The open-cell structure has macropores connected to each other and mesopores in the walls (openings) of the macropores, and is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-306976 and Japanese Translation of PCT International Publication No. 2000-501175. In JP-A-2002-306976, an oil-soluble monomer not containing an ion exchange group, a surfactant, water and a polymerization initiator as necessary are mixed to obtain a water-in-oil emulsion, which is polymerized. A monolithic organic porous body having a continuous macropore structure is obtained. JP-T-2000-501175 discloses a monolithic organic material having a continuous macropore structure by polymerizing a water-in-oil emulsion containing at least 75% by weight of an aqueous phase and containing an emulsifier such as sorbitan monooleate or polyethylene glycol polyhydroxystearic acid. A porous material is obtained.

The co-continuous structure is a structure in which a skeletal phase that is three-dimensionally continuous and a void phase that is three-dimensionally continuous between the skeleton phases are intertwined. The bicontinuous structure is disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-154083, which has an average diameter of a micrometer size, an organic high structure having a bicontinuous structure composed of pores continuous in a three-dimensional network and a skeleton phase rich in organic substances. A molecular gel-like affinity carrier, wherein the affinity carrier is at least one of a vinyl monomer compound, a methacrylate compound and an acrylate compound having at least bifunctionality as a crosslinking agent, a monofunctional hydrophilic monomer, And an affinity carrier in which the volume ratio of the cross-linking agent to the monofunctional hydrophilic monomer in the affinity carrier is 100 to 10: 0 to 90. Moreover, the particle aggregation type structure is disclosed in, for example, Japanese Patent Publication No. 7-501140.
JP 2002-306976 A Special Table 2000-501175 JP 2007-154083 A JP 7-501140 A

  However, the organic porous ion exchangers described in JP-A-2002-306976 and JP-T-2000-501175 are common when the total pore volume is reduced and the ion exchange capacity per volume in a water-wet state is increased. Due to the structural limitation that the mesopore which becomes the opening of the material becomes remarkably small and the common opening disappears when the total pore volume is further reduced, the volume to try to achieve the practically required low pressure loss The ion exchange capacity per unit is lowered, and the pressure loss increases as the exchange capacity per unit volume is increased. In addition, the closest packing of spherical bubbles is 74% by weight in the water phase part and 26% by weight in the oil phase part, so that the water phase in the oil is less than 75% by weight and the oil phase part is 25% by weight or more. There is a problem that the type emulsion tends to cause two-phase separation and it is difficult to obtain a monolith having a continuous macropore structure.

  In addition, in the co-continuous structure described in Japanese Patent Application Laid-Open No. 2007-154083, since the affinity carrier actually obtained is nanometer-sized pores, the pressure loss when the fluid permeates is high, and the low pressure loss It was difficult to fill a deionized water production apparatus that needs to treat a large flow of water underneath to make an ion exchanger. In addition, since the affinity carrier is hydrophilic, there is a problem that a complicated operation such as a hydrophobic treatment on the surface is necessary to use it as an adsorbent for a hydrophobic substance. There is also a problem that it is not easy to introduce functional groups such as ion exchange groups into the epoxy resin.

  Therefore, a monolithic organic porous body having a completely new structure that is chemically stable, has a low pressure loss during fluid permeation, and can be used as an adsorbent having a large adsorption capacity or an ion exchanger having a large ion exchange capacity Development of was desired.

  Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and it can be used as an adsorbent having a low adsorption loss or a large adsorption capacity or an ion exchanger having a large ion exchange capacity. Another object is to provide a monolithic organic porous body that can be produced, a method for producing the same, and a monolithic organic porous ion exchanger.

  Under such circumstances, the present inventor has made extensive studies, and (1) when preparing a water-in-oil (W / O) emulsion, the concentration of the oil-soluble component (monomer) relative to the total amount of the oil-soluble component and the water-soluble component. If the ratio is 25% or more, even if a stable W / O emulsion can be formed, the opening of the macropore becomes small and the pressure loss during fluid permeation increases, and (2) the concentration of such oil-soluble components is high. When a specific surfactant is used in the W / O emulsion, part of the W / O is inverted during polymerization to form oil droplets in the water of W / O. A completely new porous structure that is a mixture of particles can be obtained. (3) Since the spherical particles floating in the open cell structure expand the macropores, the bubble portion that becomes a flow path becomes wider and the fluid permeation Lower pressure loss (4) Since the spherical particles suspended there, it found like can be increased adsorption capacity and ion exchange capacity, and have completed the present invention.

  That is, in the present invention, bubble-like macropores overlap with each other, and the overlapping part is an open continuous macropore structure skeleton part, and is dispersed in the monolithic organic porous body and is not integrated with the skeleton part. The present invention provides a monolithic organic porous material comprising spherical particles having a particle radius of 0.1 to 50 μm, a total pore volume of 1 to 5 ml / g, and a thickness of 5 mm or more.

  In the present invention, a water-in-oil emulsion is prepared by mixing a vinyl monomer, a crosslinking agent, a surfactant, water and, if necessary, a polymerization initiator, and the water-in-oil emulsion is allowed to stand. A method for producing a monolithic organic porous body by polymerization, wherein the mixing ratio of oil-soluble component and water-soluble component in preparing the water-in-oil emulsion is oil-soluble component / water-soluble component in weight ratio = 25/75 to 40/60, and as the surfactant, a high molecular weight surfactant having a number average molecular weight (Mn) of 600 to 1000 and a low molecular weight surfactant having a molecular weight of 500 or less are used as essential. A method for producing a monolithic organic porous body is provided.

  In the present invention, the macroscopic pores overlap each other, and the overlapping part is an open-ended macropore structure skeleton, and is dispersed in the monolithic organic porous body and is not integrated with the skeleton. It consists of spherical particles having a particle radius of 0.2 to 120 μm, has a total pore volume of 1 to 5 ml / g, a thickness of 5 mm or more, and a differential pressure coefficient of 0.005 to 0.1 MPa / m · The present invention provides a monolithic organic porous ion exchanger characterized by having an ion exchange capacity per volume in an LV, water-wet state of 0.3 mg equivalent / ml or more.

  The monolithic organic porous material of the present invention has a particle-agglomerated porous material or a porous material having an open-cell structure in which open spherical particles that are not integrated with the skeleton are present in the open-cell skeleton. It is a novel porous structure that is completely different from a porous body having a continuous structure. Further, according to the present invention, since the spherical particles present in the open cell structure expand the macropore and the opening diameter, the flow path through which the fluid flows is widened, and the pressure loss during fluid permeation is reduced. Further, since spherical particles are dispersed in the open cell structure, the adsorption capacity and the ion exchange capacity can be increased.

  In the present specification, “monolithic organic porous material” is also simply referred to as “monolith”, and “monolithic organic porous ion exchanger” is also simply referred to as “monolith ion exchanger”.

(Description of monolith)
The monolith of the present invention comprises a continuous macropore structure which is a skeleton part, and spherical particles having a specific size which are dispersed in the monolith and are not integrated with the skeleton part.

  The skeleton has a continuous macropore structure in which bubble-shaped macropores overlap each other, and the overlapping portion becomes a common opening (mesopore). The average diameter of the openings is 0.1 to 300 μm, preferably 1 to 250 μm, particularly 5 to 5. The inner diameter of the bubble formed by the macropore and the opening is a flow path. The number of overlapping macropores is 1 to 12 for one macropore, and 3 to 10 for many. The continuous macropore structure is preferably a uniform structure with the same macropore size and opening diameter, but is not limited to this, and the uniform structure is dotted with macropores that are larger and more uneven than the uniform macropore size. You may do. The size of most macropores is in the range of 20 to 200 μm. If the average diameter of the opening is too small, it is not preferable because the pressure loss during fluid permeation increases, and if the average diameter of the opening is too large, the contact between the fluid and the monolith becomes insufficient. Since it falls, it is not preferable. The average diameter of the openings (mesopores) refers to the maximum value of the pore distribution curve obtained by the mercury intrusion method.

  Spherical particles are particles that are dispersed in the monolith and are not integrated with the skeleton. That is, the spherical particles include those that exist in the macropores of the monolith or those that are partially embedded in the skeleton wall. When the spherical particles are present in the macropores, the spherical particles are not integrated with the skeleton, and therefore are present floating or attached to the wall surface in the macropores. Further, most of the spherical particles exist independently, but some of them may be aggregated. Aggregated spherical particles are mostly aggregates of two or three spherical particles. The term “not integrated” means that the spherical particles and the skeleton are not systematically continuous.

  The spherical particles have a particle radius of 0.1 to 50 μm, preferably 1 to 40 μm. Further, 90% of the spherical particles are in the range of 10 to 30 μm. If the spherical particle has such a size, the macropores can be expanded to expand the bubble portion. Further, since the spherical particles coexist with the skeleton having a continuous macropore structure, the adsorption capacity can be increased while keeping the pressure loss during fluid permeation low. That is, if the size of the spherical particles is too small, the macropore expansion effect cannot be expected. On the other hand, if the spherical particles are too large, the pressure loss during fluid permeation increases. In addition, the particle size of the spherical particles is larger than the size of the opening of the overlap between the macropore and the macropore in the continuous macropore structure. Thereby, spherical particles do not fall off from the bubble part of the monolith.

  The open cell structure and the size of the spherical particles of the monolith of the present invention can be observed in the SEM image of the cut surface of the monolith.

  The monolith of the present invention has a total pore volume of 1 to 5 ml / g, preferably 1.5 to 4 ml / g. If the total pore volume is too small, the pressure loss at the time of fluid permeation increases, which is not preferable. Further, the amount of permeated fluid per unit cross-sectional area decreases, and the processing capacity decreases. On the other hand, if the total pore volume is too large, the adsorption capacity per volume decreases, which is not preferable. The monolith of the present invention has a unique structure in which spherical particles coexist with a skeleton having a continuous macropore structure, and the total pore volume is in the above range. Therefore, when this is used as an adsorbent, contact with a fluid occurs. Since the area is large and fluid can be smoothly circulated, excellent performance can be exhibited.

  The pressure loss when water is allowed to permeate through the monolith is the pressure loss when water is passed through a column filled with 1 m of a porous body at a water flow velocity (LV) of 1 m / h (hereinafter referred to as “differential pressure coefficient”). In other words, it is preferably in the range of 0.005 to 0.1 MPa / m · LV, particularly 0.005 to 0.05 MPa / m · LV.

  In the monolith of the present invention, the material constituting the skeleton and spherical particles of the continuous macropore structure is an organic polymer material having a crosslinked structure. The crosslink density of the polymer material is not particularly limited, but is 0.5 to 10 mol%, preferably 1 to 8 mol% of crosslinkable structural units with respect to all structural units constituting the polymer material. preferable. If the cross-linking structural unit is less than 0.5 mol%, the mechanical strength is insufficient, which is not preferable. On the other hand, if it exceeds 10 mol%, the porous body becomes brittle and the flexibility is lost. 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.

  The monolith of the present invention has a thickness of 5 mm or more, and is distinguished from a membrane-like porous body. If the thickness is less than 5 mm, the adsorption capacity per porous body is extremely lowered, which is not preferable. The thickness of the monolith is preferably 5 mm to 1000 mm.

  When the monolith of the present invention is used as an adsorbent, for example, a cylindrical column or a square column is filled with the monolith cut into a shape that can be inserted into the column as an adsorbent, and this is filled with benzene, toluene, phenol. If the water to be treated containing a hydrophobic substance such as paraffin is allowed to flow, the hydrophobic substance is efficiently adsorbed to the adsorbent.

(Description of monolith ion exchanger)
Next, the monolith ion exchanger of the present invention will be described. In the monolith ion exchanger, the description of the same components as those of the monolith is omitted, and different points are mainly described. The skeleton is a continuous macropore structure in which bubble-shaped macropores overlap each other, and the overlapping portion becomes an opening (mesopore) having an average diameter of 0.2 to 750 μm, preferably 1 to 500 μm, particularly 5 to 400 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 opening is too small, it is not preferable because the pressure loss during fluid permeation increases, and if the average diameter of the opening is too large, the contact between the fluid and the monolith ion exchanger becomes insufficient. This is not preferable because the ion exchange characteristics deteriorate. The average diameter of the opening can be obtained by a value calculated by multiplying the average diameter of the porous body before the introduction of the ion exchange group by the swelling rate of the porous body before and after the introduction of the ion exchange group.

  In the monolith ion exchanger, the size of the spherical particles is 0.2 to 120 μm, preferably 1 to 100 μm, particularly 5 to 80 μm. If the spherical particle has such a size, the macropores can be expanded to expand the bubble portion. In addition, since the spherical particles coexist with the skeleton having a continuous macropore structure, the ion exchange capacity can be increased while keeping the pressure loss during fluid permeation low.

  The total pore volume of the monolith ion exchanger is the same as the total pore volume of the monolith. That is, even if the ion exchange group is introduced into the monolith to swell and the opening diameter becomes large, the spherical particles also swell and become large, so that the total pore volume hardly changes. If the total pore volume is less than 1 ml / g, the pressure loss at the time of fluid permeation increases, which is not preferable. Further, the amount of permeated fluid 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.

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

  The monolith ion exchanger of the present invention has an ion exchange capacity per volume in a water-wet state of 0.3 mg equivalent / ml or more, preferably 0.3 to 1.8 mg equivalent / ml. 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 enlarges the macropores by spherical particles and has a skeleton part with a continuous macropore structure, so that the ion exchange capacity per volume is greatly increased while keeping the pressure loss low. can do. If the ion exchange capacity per volume is less than 0.3 mg equivalent / ml, the amount of water containing ions that can be processed before breakthrough, that is, the ability to produce deionized water is not preferred. The ion exchange capacity per weight of the monolith ion exchanger of the present invention is not particularly limited, but the ion exchange groups are uniformly introduced to the surface of the porous body and the inside of the skeleton and the surface of the spherical particles and the inside of the particles. Therefore, it is 3-5 mg equivalent / g. 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.

  Examples of the ion exchange group introduced into the monolith of the present invention include cation exchange groups such as a sulfonic acid group, a carboxylic acid group, an iminodiacetic acid group, a phosphoric acid group, and a phosphoric ester group; a quaternary ammonium group, a tertiary amino group, Examples include anion exchange groups such as secondary amino group, primary amino group, polyethyleneimine group, tertiary sulfonium group, and phosphonium group; amphoteric ion exchange groups such as aminophosphate group and sulfobetaine.

  In the monolith ion exchanger of the present invention, the introduced ion exchange groups are uniformly distributed not only on the surface of the porous body and spherical particles but also inside the skeleton of the porous body and spherical particles. 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.

(Monolith manufacturing method)
Next, a method for manufacturing a monolith will be described. That is, the monolith is prepared by mixing a vinyl monomer, a crosslinking agent, a surfactant, water and, if necessary, a polymerization initiator to prepare a water-in-oil emulsion, and the water-in-oil emulsion is left standing. Although obtained by polymerization, the mixing ratio of the oil-soluble component and the water-soluble component (hereinafter also simply referred to as “oil-soluble component concentration”) when preparing the water-in-oil emulsion is set within a specific range. Use a specific surfactant.

  The vinyl monomer used in the present invention is not particularly limited as long as it contains a polymerizable vinyl group in the molecule, has low solubility in water, and exhibits lipophilicity. Specific examples of these vinyl monomers include styrene monomers such as styrene, α-methylstyrene, vinyl toluene, and vinyl benzyl chloride; α-olefins such as ethylene, propylene, 1-butene, and isobutene; butadiene, isoprene, chloroprene, and the like. Diene monomers; Halogenated olefins 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 and Acrylic Ethyl acetate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexane methacrylate Examples include (meth) acrylic monomers such as hexyl, benzyl methacrylate, and 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 a styrene monomer such as styrene or vinyl benzyl chloride.

  As the crosslinking agent used in the present invention, those containing at least two polymerizable vinyl groups in the molecule are 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. It is important to use the crosslinking agent in a proportion of 1 to 10% with respect to the total amount of the vinyl monomer and the crosslinking agent. If the cross-linking agent is used in excess of 10%, the size of the macropore opening is reduced, which is not preferable. On the other hand, when the amount of the crosslinking agent used is less than 1%, the mechanical strength of the porous body is insufficient, and it is not preferable because the porous body is greatly deformed during water passage or the porous body is destroyed.

  The surfactant used in the present invention is a mixture of a high molecular weight surfactant having a number average molecular weight (Mn) of 600 to 1000 and a low molecular weight surfactant having a molecular weight of 500 or less, preferably 100 to 500. A water-in-oil emulsion can be formed when an oil-soluble monomer containing no ion exchange group and water are mixed and the concentration of the oil-soluble component is increased to 25% or higher. Since the monolith described in JP-A-2002-306976 had an oil-soluble component concentration of 10% or 15%, a stable water-in-oil emulsion could be formed even by using a low molecular weight surfactant alone. However, when the concentration of the oil-soluble component is 25% or more, the use of a low molecular weight surfactant alone causes a problem that the water-in-oil emulsion collapses during the reaction and separates into two phases. In the present invention, in order to stabilize the water-in-oil emulsion, when a high molecular weight surfactant and a low molecular weight surfactant are used in combination, unexpectedly, a floating state that is not integrated with the skeleton in the open-cell skeleton A unique porous structure in which spherical particles exist is obtained. In addition, when a high molecular weight surfactant is used alone, a monolith having a continuous macropore structure similar to the conventional one can be obtained. The number average molecular weight is based on polystyrene conversion in GPC measurement.

  The high molecular weight surfactant is a polyethylene glycol fatty acid ester, specifically poly (ethylene glycol) bis (2-ethylhexanoate), poly (ethylene glycol) dioleate, poly (ethylene glycol) distearate, poly (ethylene). Glycol) bis (polyhydroxystearate) and other ABA type block copolymers. These high molecular weight surfactants can be used alone or in combination of two or more.

  As the low molecular weight surfactant, nonionic surfactants such as sorbitan monooleate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan trioleate and the like can be used. These low molecular weight surfactants can be used singly or in combination of two or more.

  The blending ratio of the high molecular weight surfactant and the low molecular weight surfactant is such that the weight ratio of high molecular weight surfactant / low molecular weight surfactant = 5/95 to 95/5 can be used in a stable oil. It is preferable in that a water droplet emulsion can be formed and spherical particles can be dispersed in an open cell structure. If the high molecular weight surfactant is less than 5%, a stable water-in-oil emulsion cannot be obtained, and if it exceeds 95%, spherical particles are not formed.

  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 varies greatly depending on the type of the oil-soluble monomer and the size of the target emulsion particles (macropores). On the other hand, it can be selected within a range of 2 to 20%.

  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 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), Examples include benzoyl oxide, potassium persulfate, ammonium persulfate, hydrogen peroxide-ferrous chloride, sodium persulfate-sodium acid sulfite, and tetramethylthiuram disulfide. However, in some cases, there is a system in which polymerization proceeds only by heating or light irradiation without adding an initiator, and in such a system, it is not necessary to add an initiator.

  There are no particular restrictions on the mixing method used to form a water-in-oil emulsion by mixing a vinyl monomer, a cross-linking agent, a surfactant, water and, if necessary, a polymerization initiator. Method of mixing at once; after dissolving oil-soluble monomer, surfactant and oil-soluble component which is oil-soluble polymerization initiator and water-soluble component which is water or water-soluble polymerization initiator separately and uniformly, A method of mixing the components can be used.

  In the method for producing a monolith, the mixing ratio of the oil-soluble component and the water-soluble component when preparing the water-in-oil emulsion is such that the oil-soluble component / water-soluble component is 25/75 to 40/60, preferably 26 / 74 to 36/64. If it is less than 25% by weight, a monolith having a continuous macropore structure can only be produced, and a monolith having a structure unique to the present invention cannot be obtained. The oil-soluble component refers to a vinyl monomer, a crosslinking agent, and an oil-soluble polymerization initiator, and the water-soluble component refers to water and a water-soluble polymerization initiator.

  As a mixing apparatus for forming an emulsion, the object to be processed is stirred and mixed by putting the object to be processed in a mixing container and rotating while revolving around the revolution axis in a state where the mixing container is inclined. A so-called planetary stirring device can be used. This planetary stirring apparatus is an apparatus disclosed in, for example, Japanese Patent Application Laid-Open Nos. 6-71110 and 11-104404. The principle of this device is to rotate the mixing container while revolving, using its centrifugal force action to move the heavy component in the workpiece to the outside and stir it, and to reverse the mixed gas It extrudes in the direction and defoams. Further, since the container rotates while revolving, a spiral flow (vortex) is generated in the object to be processed in the container, and the stirring action is enhanced. The apparatus may be operated under atmospheric pressure, but is preferably operated under reduced pressure in order to perform defoaming completely in a short time.

  Moreover, the mixing conditions can set arbitrarily the revolution and rotation speed which can obtain the target emulsion particle size and distribution, and stirring time. A preferable revolution speed is about 500 to 2000 revolutions / minute, although it depends on the size and shape of the container to be rotated. Moreover, a preferable rotation speed is a rotation speed around 1/3 of the revolution speed. The stirring time also varies greatly depending on the properties of the contents and the shape and size of the container, but is generally set between 0.5 and 30 minutes, preferably between 1 and 20 minutes. Furthermore, the shape of the container to be used is preferably a shape capable of accommodating the filling so that the height of the filling is 0.5 to 5 with respect to the bottom diameter.

  Various conditions can be selected as the polymerization conditions for polymerizing the water-in-oil emulsion thus obtained depending on the type of monomer and the initiator system. For example, when azobisisobutyronitrile, benzoyl peroxide, potassium persulfate, or the like is used as an initiator, it may be heated and polymerized at 30 to 100 ° C. for 1 to 48 hours in a sealed container under an inert atmosphere. When hydrogen peroxide-ferrous chloride, sodium persulfate-acidic sodium sulfite, or the like is used as an initiator, polymerization may be performed at 0-30 ° C. for 1-48 hours in a sealed container under an inert atmosphere. . After completion of the polymerization, the content is taken out and, if necessary, extracted with a solvent such as acetone or 2-propanol to obtain an organic porous material for the purpose of removing unreacted monomer and surfactant.

  Although it is unclear why the water-in-oil emulsion polymerizes to give a mixture of open-cell structure and floating spherical particles, the oil in the water-in-oil emulsion polymerizes to form a skeleton structure and spherical particles. This is probably because part of the water-in-oil emulsion is inverted during polymerization to form oil droplets in the water of the water-in-oil emulsion.

(Method for producing monolithic ion exchanger)
Next, the manufacturing method of the monolith ion exchanger of this invention is demonstrated. The production method of the monolith ion exchanger is not particularly limited, but the method of introducing the ion exchange group after producing the monolith by the above method can strictly control the porous structure of the obtained monolith ion exchanger. This is preferable.

  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 introducing a mobile group into the skeleton surface and inside the skeleton, and the surface and inside of the spherical particles, and graft polymerizing sodium styrenesulfonate or acrylamide-2-methylpropanesulfonic acid; after graft polymerization of glycidyl methacrylate in the same manner, Examples thereof include a method of introducing a sulfonic acid group by functional group conversion. 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; and amphoteric ion exchange groups such as aminophosphate groups, betaines and sulfobetaines.

  The monolith ion exchanger of the present invention swells greatly, for example, 1.4 to 2.5 times that of the monolith because the ion exchange group is introduced into 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 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 monolith ion exchanger of the present invention can increase the ion exchange capacity per volume in a water-wet state by the continuous macropore structure skeleton and the spherical particles dispersed in the skeleton, and the water to be treated has a low pressure and a large capacity. Water can be passed for a long time at a flow rate, and it can be suitably used by filling a two-bed, three-column pure water production apparatus or an electric deionized water production apparatus.

  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 monolithic organic porous material)
58.6 g of styrene, 1.2 g of divinylbenzene, 1.86 g of poly (ethylene glycol) bis (polyhydroxystearate) having a number average molecular weight (Mn) of 1000 (“Hypermer 1084”, manufactured by Unikema), and having a molecular weight of 428 1.86 g of sorbitan monooleate and 0.13 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were mixed and dissolved uniformly. Next, the mixture was put in a polyethylene cylindrical container, and 140 g of pure water was added. Using a vacuum stirring defoaming mixer (“VMX-360”, manufactured by EM Corporation), which is a planetary stirring device, stirring is performed for 5 minutes at a revolution speed of 1800 rpm and a rotation speed of 600 rpm under a reduced pressure in a temperature range of 5 to 20 ° C. Thus, a water-in-oil emulsion was obtained. This emulsion was immediately transferred to a reaction vessel sufficiently substituted with nitrogen, and after sealing, it was allowed to stand and polymerized at 60 ° C. for 24 hours. After completion of the polymerization, the contents were taken out, extracted with Soxhlet for 8 hours with acetone to remove unreacted monomer and surfactant, and then dried under reduced pressure at 85 ° C. overnight. The obtained cylindrical monolithic organic porous body had a diameter of 59 mm. The oil-soluble component concentration during preparation of the water-in-oil emulsion is 31%, and the water-soluble component concentration is 69%.

  SEM photographs of the monolith made of the styrene-divinylbenzene copolymer thus obtained are shown in FIG. 1 (150 times) and FIG. 2 (600 times). As apparent from FIGS. 1 and 2, the monolith had a continuous macropore structure as a skeleton, and spherical particles were not systematically continuous with the skeleton, and had a structure in which the monolith was dispersed and coexisted in the monolith. Most of the spherical particles existed as one in the macropore, some existed as 3 to 5 in the macropore, and some existed so as to be partially embedded in the skeleton. Some spherical particles existed so as to straddle two macropores, and existed to expand the diameter of the macropores. Moreover, the average diameter of the opening of the monolith measured by mercury porosimetry was 16 μm, and the total pore volume was 1.24 ml / g. The pore distribution curve is shown in FIG. The results are summarized in Table 1. In Table 1, “PEG” is an abbreviation for poly (ethylene glycol).

  Monolith in the same manner as in Example 1 except that poly (ethylene glycol) bis (polyhydroxystearate) is replaced with poly (ethylene glycol) bistearate (manufactured by Aldrich) instead of poly (ethylene glycol) bis (polyhydroxystearate). Manufactured. A SEM photograph of the monolith is shown in FIG. The observation result by the SEM image of FIG. 4 was the same as that of Example 1. Moreover, the average diameter of the opening of the said monolith measured by the mercury intrusion method was 12 micrometers, and the total pore volume was 1.22 ml / g. The results are summarized in Table 1.

  A monolith was prepared in the same manner as in Example 1 except that the high molecular weight surfactant was replaced with poly (ethylene glycol) bis (polyhydroxystearate) and poly (ethylene glycol) dioleate (manufactured by Aldrich) having Mn of 871. Manufactured. An SEM photograph of this monolith is shown in FIG. The observation result by the SEM image of FIG. Moreover, the average diameter of the opening of the monolith measured by the mercury intrusion method was 13 μm, and the total pore volume was 1.19 ml / g. The results are summarized in Table 1.

  Except that the high molecular weight surfactant was replaced with poly (ethylene glycol) bis (polyhydroxystearate) and poly (ethylene glycol) bis (2-ethylhexanoate) (manufactured by Aldrich) having Mn of 622. A monolith was produced in the same manner as in Example 1. An SEM photograph of this monolith is shown in FIG. The observation result by the SEM image of FIG. 6 was the same as that of Example 1. Moreover, the average diameter of the opening of the monolith measured by mercury porosimetry was 8 μm, and the total pore volume was 1.15 ml / g. The results are summarized in Table 1.

  A monolith was produced in the same manner as in Example 1 except that divinylbiphenyl was used instead of divinylbenzene. That is, Example 5 changes the kind of crosslinking agent. An SEM photograph of this monolith is shown in FIG. The observation result by the SEM image of FIG. Moreover, the average diameter of the opening of the said monolith measured by the mercury intrusion method was 14 micrometers, and the total pore volume was 1.20 ml / g. The results are summarized in Table 1.

  A monolith was produced in the same manner as in Example 1 except that 49.0 g of styrene, 1.0 g of divinylbenzene and 150 g of pure water were used instead of 58.8 g of styrene, 1.2 g of divinylbenzene and 140 g of pure water. In Example 6, the oil-soluble component concentration during preparation of the water-in-oil emulsion was 26%, and the water-soluble component concentration was 74%. An SEM photograph of this monolith is shown in FIG. The observation result by the SEM image in FIG. 8 was the same as in Example 1. Moreover, the average diameter of the opening of the monolith measured by mercury porosimetry was 10 μm, and the total pore volume was 2.46 ml / g. The results are summarized in Table 1.

  A monolithic organic material was prepared in the same manner as in Example 1, except that 49.0 g of vinylbenzyl chloride, 1.0 g of divinylbenzene and 150 g of pure water were used instead of 58.8 g of styrene, 1.2 g of divinylbenzene and 140 g of pure water. A porous body was produced. In Example 7, the oil-soluble component concentration during preparation of the water-in-oil emulsion was 26%, and the water-soluble component concentration was 74%. An SEM photograph of this monolith is shown in FIG. The observation result by the SEM image of FIG. 9 was the same as that of Example 1. Moreover, the average diameter of the opening of the monolith measured by mercury porosimetry was 6 μm, and the total pore volume was 1.16 ml / g. The results are summarized in Table 1.

  A monolith was produced in the same manner as in Example 1 except that 68.6 g of styrene, 1.4 g of divinylbenzene and 130 g of pure water were used instead of 58.8 g of styrene, 1.2 g of divinylbenzene and 140 g of pure water. In Example 8, the oil-soluble component concentration in the preparation of the water-in-oil emulsion was 36%, and the water-soluble component concentration was 64%. An SEM photograph of this monolith is shown in FIG. The observation result by the SEM image of FIG. 10 was the same as that of Example 1. Moreover, the average diameter of the opening of the monolith measured by mercury porosimetry was 7 μm, and the total pore volume was 1.10 ml / g. The results are summarized in Table 1.

Comparative Example 1
A monolith was prepared in the same manner as in Example 1 except that poly (ethylene glycol) bis (polyhydroxystearate) was not used and that 3.83 g was used instead of 1.86 g of sorbitan monooleate. Manufactured. After the polymerization was completed, the contents were taken out and phase separation occurred. From this result, it can be seen that in a water-in-oil emulsion having an oil-soluble component concentration of 31%, if a high molecular weight surfactant is not used, a continuous macropore structure or a unique feature of the present invention can be achieved even if the amount of the low molecular weight surfactant is increased. It can be seen that a porous body having a simple structure cannot be obtained.

Comparative Example 2
The use of sorbitan monooleate, 3.16 g instead of 1.86 g of poly (ethylene glycol) bis (polyhydroxystearate), 10 minutes instead of 5 minutes of stirring time A monolith was produced in the same manner as in Example 1 except that. FIG. 11 shows an SEM photograph of a monolith made of the styrene-divinylbenzene copolymer thus obtained. As is clear from FIG. 11, although a continuous macropore structure was formed, the presence of spherical particles was not recognized. Moreover, the average diameter of the opening of the monolith measured by the mercury intrusion method was 6 μm, and the total pore volume was 0.57 ml / g. The pore distribution curve is shown in FIG. From this result, it is a water-in-oil emulsion with an oil-soluble component concentration of 31%, and if a low molecular weight surfactant is not used, a continuous macropore structure can be achieved even if the amount of high molecular weight surfactant is increased and the stirring is prolonged. It can be seen that a porous body having a unique structure of the present invention cannot be obtained. This continuous macropore structure also had a small monolith opening diameter and total pore volume, and a large proportion of the skeleton portion.

Comparative Example 3
The monolith was prepared in the same manner as in Example 6 except that sorbitan monooleate was not used and that the poly (ethylene glycol) bis (polyhydroxystearate) was used in an amount of 2.63 g instead of 1.86 g. Manufactured. An SEM photograph of a monolith made of the styrene-divinylbenzene copolymer thus obtained is shown in FIG. As is clear from FIG. 13, although a continuous macropore structure was formed, the presence of spherical particles was not recognized. Moreover, the average diameter of the opening of the monolith measured by the mercury intrusion method was 7 μm, and the total pore volume was 0.98 ml / g. The results are shown in Table 1.

(Production of monolith cation exchanger)
The monolith produced in Example 6 was cut into a disk shape having a thickness of 15 mm, and 15.9 g was fractionated. To this was added 1000 ml of dichloromethane, heated at 35 ° C. for 30 minutes, cooled to 10 ° C. or lower, gradually added 87.1 g of chlorosulfonic acid, heated again, and reacted at 35 ° C. for 24 hours. Thereafter, the mixture was cooled to room temperature and methanol was added to quench the remaining chlorosulfonic acid, followed by washing with methanol to remove dichloromethane and further washing with pure water to obtain a monolithic organic porous cation exchanger. The obtained cation exchanger had a diameter of 145 mm and an ion exchange capacity per volume of 0.47 mg equivalent / ml in a water-wet state. The differential pressure coefficient, which is an index of pressure loss when water is permeated, is 0.024 MPa / m · LV, which is a lower pressure loss than the pressure loss that is practically required. The results are summarized in Table 2.

(Production of monolith anion exchanger)
The monolith produced in Example 7 was cut into a disk shape having a thickness of 15 mm, and 21.7 g was fractionated. To this was added 1000 ml of tetrahydrofuran, heated at 40 ° C. for 1 hour, cooled to 10 ° C. or less, gradually added with 140 g of a 30% trimethylamine aqueous solution, heated to react at 40 ° C. for 24 hours. After completion of the reaction, the product was taken out and washed with methanol and pure water in this order to obtain a monolithic organic porous anion exchanger. The obtained anion exchanger had a diameter of 100 mm and an ion exchange capacity per volume of 0.34 mg equivalent / ml in a wet state. The differential pressure coefficient, which is an index of pressure loss when water is permeated, was 0.042 MPa / m · LV. The results are shown in Table 2.

  In place of 15.9 g of the monolith produced in Example 6, 14.8 g of the monolith produced in Example 1 was fractionated, except that the amount of chlorosulfonic acid used was 81.1 g instead of 81.1 g. Produced a monolithic organic porous cation exchanger in the same manner as in Example 9. The obtained cation exchanger had a diameter of 144 mm and an ion exchange capacity per volume of 0.37 mg equivalent / ml in a wet state. The differential pressure coefficient, which is an index of pressure loss when water is permeated, was 0.054 MPa / m · LV. The results are shown in Table 2.

  In place of 19.9 g of the monolith produced in Example 6 instead of 15.9 g of the monolith produced in Example 6, except that 19.8 g of the monolith produced in Example 8 was fractionated, and that the amount of chlorosulfonic acid used was 88.9 g, instead of 108.9 g. Produced a monolithic organic porous cation exchanger in the same manner as in Example 9. The results are shown in Table 2. The obtained cation exchanger had a diameter of 149 mm and an ion exchange capacity per volume of 0.37 mg equivalent / ml in a wet state. The differential pressure coefficient, which is an index of pressure loss when water is permeated, was 0.100 MPa / m · LV. The results are shown in Table 2.

Comparative Example 4
In place of 15.9 g of the monolith produced in Example 6, 10.6 g of the monolith produced in Comparative Example 3 was fractionated, except that the amount of chlorosulfonic acid used was 88.2 g, instead of 58.2 g. Produced a monolithic organic porous cation exchanger in the same manner as in Example 9. The obtained cation exchanger had a diameter of 123 mm and an ion exchange capacity per volume of 0.34 mg equivalent / ml in a wet state. The differential pressure coefficient, which is an index of pressure loss when water is permeated, was 0.175 MPa / m · LV. The results are shown in Table 2.

Comparative Example 5
In place of 15.9 g of the monolith produced in Example 6, 16.2 g of the organic porous material produced in Comparative Example 2 was fractionated, and instead of using 87.1 g of chlorosulfonic acid, 89.1 g Except for the above, the product was produced in the same manner as in Example 9. As a result, this monolith cation exchanger was cracked and the center was unreacted.

  Since the monolithic organic porous material and the monolithic organic porous ion exchanger of the present invention have a novel and unique porous structure, they have features such as large adsorption capacity and ion exchange capacity and extremely low pressure loss. is doing. For this reason, filters and adsorbents; ion exchangers used by filling 2-bed 3-tower pure water production equipment and electrical deionized water production equipment; various chromatographic fillers; useful as solid acid / base catalysts It can be applied to a wide range of application fields.

2 is a SEM photograph (150 times) of an organic porous material obtained in Example 1. FIG. 2 is an SEM photograph (600 times) of an organic porous material obtained in Example 1. FIG. 2 is a pore distribution curve of an organic porous material obtained in Example 1. 2 is a SEM photograph of the organic porous material obtained in Example 2. 4 is a SEM photograph of the organic porous material obtained in Example 3. 4 is a SEM photograph of the organic porous material obtained in Example 4. 6 is a SEM photograph of the organic porous material obtained in Example 5. 4 is a SEM photograph of the organic porous material obtained in Example 6. 4 is a SEM photograph of the organic porous material obtained in Example 7. 6 is a SEM photograph of the organic porous material obtained in Example 8. 3 is a SEM photograph of the organic porous material obtained in Comparative Example 2. 3 is a pore distribution curve of an organic porous material obtained in Comparative Example 2. 4 is a SEM photograph of the organic porous material obtained in Comparative Example 3.

Claims (4)

  Bubble-shaped macropores overlap each other, and a skeleton having a continuous macropore structure in which the overlapping portion becomes an opening, and a particle radius of 0.1 to 0.1 which is dispersed in the monolithic organic porous body and not integrated with the skeleton A monolithic organic porous material comprising spherical particles of 50 μm, having a total pore volume of 1 to 5 ml / g and a thickness of 5 mm or more.   A water-in-oil emulsion is prepared by mixing a vinyl monomer, a cross-linking agent, a surfactant, water and, if necessary, a polymerization initiator, and the water-in-oil emulsion is allowed to polymerize by standing to form a monolithic organic material. A method for producing a porous body, wherein the mixing ratio of the oil-soluble component and the water-soluble component in preparing the water-in-oil emulsion is such that the oil-soluble component / water-soluble component = 25 / 75-40 by weight ratio. A monolithic organic porous material comprising a high molecular weight surfactant having a number average molecular weight (Mn) of 600 to 1000 and a low molecular weight surfactant having a molecular weight of 500 or less as the essential surfactant. Body manufacturing method.   The method for producing a monolithic organic porous material according to claim 2, wherein the high molecular weight surfactant is a polyethylene glycol fatty acid ester.   Bubble-shaped macropores overlap with each other, and a skeleton having a continuous macropore structure in which the overlapping portion becomes an opening, and a particle radius of 0.2 to not dispersed with the skeleton while being dispersed in the monolithic organic porous body It consists of 120 μm spherical particles, has a total pore volume of 1 to 5 ml / g, a thickness of 5 mm or more, a differential pressure coefficient during water passage of 0.005 to 0.1 MPa / m · LV, in a wet state A monolithic organic porous ion exchanger having an ion exchange capacity per volume of 0.3 mg equivalent / ml or more.

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