JP2010264346A - Solid acid catalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid acid catalyst which has remarkably improved permeability of a gas or liquid consisting of a raw material, a product or a mixture thereof while keeping satisfactorily high catalytic activity, has a special structure and consists of a porous ion exchanger. <P>SOLUTION: The solid acid catalyst is a composite structure composed of: an organic porous body composed of a continuous skeleton phase and a continuous pore phase; many particulate bodies which are stuck to the surfaces of a skeleton of the organic porous body and each of which has 4-40 μm diameter; and many projections which are formed on the surfaces of the skeleton of the organic porous body and each of which has 4-40 μm size and consists of the monolithic organic porous cation exchanger. The organic porous body has 10-150 μm average pore diameter in a water-wet state, 0.5-5 ml/g total pore volume and 1-5 mg-equivalent/g cation exchange capacity in a dry state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solid acid catalyst that allows an organic reaction to proceed efficiently in a short time and at a high reaction rate.

  Conventionally, silica / alumina compounds such as zeolite, heteropolyacids, cation exchange resins, etc. are known as solid acid catalysts, but when used in a system containing water except for cation exchange resins. The solid acid catalyst used in the water-containing system is mostly a cation exchange resin because it cannot be used because its activity is remarkably lowered or dissolved.

  In order to increase the catalytic activity of the cation exchange resin, it is known that the particle size of the cation exchange resin should be reduced. However, the reaction column is filled with the cation exchange resin and the liquid to be treated is continuously added. When supplying, if the particle diameter is reduced, the permeation resistance of the liquid to be treated increases, and the treatment amount cannot be increased while maintaining a large catalytic activity. In addition, as a method for making the reaction proceed more efficiently, a method using reactive distillation is known. If a conventional granular cation exchange resin is used as a solid acid catalyst for reactive distillation, the cation exchange resin is distilled. Application to reactive distillation has been difficult because the column filling significantly impedes the permeability of gases and liquids consisting of raw materials and reaction products.

  Therefore, as a method for solving the above-mentioned drawbacks, it has an open cell structure having mesopores having an average diameter of 1 to 1,000 μm in the macropores and the walls of the macropores, and the total pore volume is 1 to 50 ml / g. A solid acid catalyst (Japanese Patent Laid-Open No. 2002-346392) comprising a porous ion exchanger in which the cation exchange groups are uniformly distributed and the cation exchange capacity is 0.5 mg equivalent / g or more of a dry porous body. Proposed. This solid acid catalyst has a high cation exchange group density, a large pore volume and a specific surface area, so that it exhibits high catalytic activity and permeability of gases and liquids composed of raw materials or products, or mixtures thereof. The organic reaction can be efficiently advanced in a short time and at a high reaction rate. Japanese Patent Laid-Open No. 2002-306976 discloses details of a method for producing this porous ion exchanger.

JP 2002-346392 A (Claims) JP 2002-306976 A JP 2009-62512 A JP 2009-67982 A

  However, in the solid acid catalyst disclosed in Japanese Patent Application Laid-Open No. 2002-346392, the common opening (mesopore) of the monolith is described as 1 to 1,000 μm, but the pore volume is small with a total pore volume of 5 ml / g or less. For monoliths, the amount of water droplets in the water-in-oil emulsion needs to be reduced, so that the common aperture is small, and it is not possible to produce a substantially average aperture of 20 μm or more. For this reason, there existed a problem that water flow differential pressure | voltage will become large. Further, the solid acid catalyst disclosed in JP-A No. 2002-346392 has sufficient catalytic activity, but there is room for improvement in terms of obtaining a high-purity product in which unreacted substances remain in the reaction product. . Moreover, the appearance of a monolith having a new structure different from the solid acid catalyst (open cell structure) disclosed in JP-A-2002-346392 has been desired.

  Therefore, the object of the present invention is to suppress the remaining amount of unreacted substances while maintaining a sufficiently high catalytic activity, and to significantly improve the permeability of gases and liquids composed of raw materials or products, or mixtures thereof. An object of the present invention is to provide a solid acid catalyst comprising a porous ion exchanger having a novel structure.

  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 a vinyl monomer and a crosslinking agent are allowed to stand in an organic solvent under specific conditions, a large number of particles having a diameter of 2 to 20 μm are fixed on the surface of the skeleton constituting the organic porous body, or a protrusion. A monolith having a composite structure in which an ion exchange group is formed is obtained, and a composite monolith ion exchanger in which an ion exchange group is introduced into this composite monolith is used as a solid acid catalyst, while maintaining a sufficiently high catalytic activity and unreacted. The inventors have found that the remaining amount of the product can be suppressed and the permeability of the gas or liquid made of the raw material or product, or a mixture thereof can be remarkably improved, and the present invention has been completed.

  That is, the present invention relates to an organic porous body composed of a continuous skeleton phase and a continuous pore phase, a large number of particles having a diameter of 4 to 40 μm fixed to the skeleton surface of the organic porous body, or the skeleton of the organic porous body. A composite structure with a large number of protrusions having a size of 4 to 40 μm formed on the surface, with an average pore diameter of 10 to 150 μm and a total pore volume of 0.5 to 5 ml / g in a wet state. The present invention provides a solid acid catalyst comprising a monolithic organic porous cation exchanger having a cation exchange capacity of 1 to 5 mg equivalent / g dry porous body.

  The solid acid catalyst comprising a porous ion exchanger having a novel structure according to the present invention has a higher contact efficiency represented by the ion exchange zone length, and therefore exhibits higher catalytic activity and suppresses the remaining amount of unreacted substances. The permeability of gas or liquid made of raw materials or products or mixtures thereof is remarkably excellent.

2 is a SEM image of the monolith obtained in Example 1 at a magnification of 100. FIG. 2 is an SEM image of the monolith obtained in Example 1 at a magnification of 300. FIG. 2 is an SEM image of the monolith obtained in Example 1 at a magnification of 3000. 2 is an EPMA image showing the distribution state of sulfur atoms on the surface of the monolith cation exchanger obtained in Example 1. FIG. 2 is an EPMA image showing the distribution state of sulfur atoms in the cross-section (thickness) direction of the monolith cation exchanger obtained in Example 1. FIG. 4 is a SEM image of a monolith obtained in Example 2 at a magnification of 100. FIG. 4 is a SEM image of a monolith obtained in Example 2 at a magnification of 600. FIG. 3 is a SEM image of the monolith obtained in Example 2 at a magnification of 3000. 4 is a SEM image of a monolith obtained in Example 3 at a magnification of 600. FIG. 4 is an SEM image of the monolith obtained in Example 3 at a magnification of 3000. 4 is an SEM image of the monolith obtained in Example 4 at a magnification of 3000. 6 is a SEM image of a monolith obtained in Example 5 at a magnification of 100. FIG. 6 is an SEM image of the monolith obtained in Example 5 at a magnification of 3000. It is typical sectional drawing of a protrusion.

  The solid acid catalyst of the present invention is a monolithic organic porous cation exchanger having a composite structure. In the present specification, “monolithic organic porous body” is simply referred to as “composite monolith” and “monolithic organic porous cation exchanger” or “monolithic organic porous ion exchanger” is simply referred to as “composite monolithic ion exchanger”. "Monolithic organic porous intermediate" is also simply referred to as "monolith intermediate".

<Description of composite monolith ion exchanger>
A composite monolith ion exchanger is obtained by introducing an ion exchange group into a composite monolith, and is fixed to an organic porous body composed of a continuous skeleton phase and a continuous pore phase, and to the skeleton surface of the organic porous body. An organic porous body consisting of a continuous skeleton phase and a continuous pore phase, and a size formed on the skeleton surface of the organic porous body. A composite structure with a large number of protrusions having a thickness of 4 to 40 μm, having an average pore diameter of 10 to 150 μm, a total pore volume of 0.5 to 5 ml / g in a water-wet state, and a cation exchange capacity of 1 ˜5 mg equivalent / g dry porous body, and cation exchange groups are uniformly distributed in the composite structure. In the present specification, “particle bodies” and “projections” may be collectively referred to as “particle bodies”.

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

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

  In the case of the first organic porous ion exchanger, the organic porous body is a continuous macropore structure in which bubble-shaped macropores are overlapped with each other, and the overlapping portions form openings (mesopores) having an average diameter of 30 to 150 μm in a wet state. It is. The average diameter of the opening of the composite monolith ion exchanger is larger than the average diameter of the opening of the composite monolith in a dry state because the entire composite monolith swells when an ion exchange group is introduced into the monolith. If the average diameter of the openings is less than 30 μm, the pressure loss during the permeation of the liquid or gas increases, which is not preferable. If the average diameter of the openings is too large, contact between the liquid or gas and the composite monolith ion exchanger Becomes unsatisfactory, and as a result, the reaction efficiency by the catalyst decreases, which is not preferable.

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

  In the case of the second organic porous body ion exchanger, the organic porous body has a three-dimensionally continuous skeleton having an average diameter of 1 to 60 μm in a water-wet state, and an average diameter between the skeletons in a water-wet state. It is a co-continuous structure having three-dimensionally continuous pores of 10 to 100 μm. If the diameter of the three-dimensionally continuous pores is less than 10 μm, the pressure loss at the time of permeation of the liquid or gas increases, which is not preferable, and if it exceeds 100 μm, the liquid or gas and the monolith ion exchanger The contact becomes insufficient, and as a result, the reaction efficiency by the catalyst is lowered, which is not preferable.

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

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

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

  In the composite monolith ion exchanger according to the present invention, the diameter of the particles and the size of the protrusions in a wet state are 4 to 40 μm, preferably 4 to 30 μm, and particularly preferably 4 to 20 μm. In the present invention, both the particles and the protrusions are observed as protrusions on the surface of the skeleton, and the particles observed are referred to as particles, and the protrusions that are not granular are protrusions. Called the body. FIG. 14 shows a schematic cross-sectional view of the protrusion. As shown to (A)-(E) in FIG. 14, the protrusion-shaped thing protruded from the skeleton surface 61 is the protrusion 62, and the protrusion 62 is like the protrusion 62a shown to (A). The shape close to a granular shape, a hemispherical shape like a projection 62b shown in (B), and a swell of the skeleton surface like a projection 62c shown in (C). In addition, the protrusion 61 has a shape that is longer in the direction perpendicular to the skeleton surface 61 than in the plane direction of the skeleton surface 61, like the protrusion 62d shown in FIG. There is a thing of the shape which protruded in the several direction like the protrusion 62e shown to (E). Further, the size of the protrusions is determined by the SEM image when observed by SEM, and indicates the length of the portion where the width of each protrusion is the largest in the SEM image.

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

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

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

  The total pore volume of the composite monolith ion exchanger is the same as the total pore volume of the composite monolith. That is, even when the ion exchange group is introduced into the composite monolith to swell and increase the opening diameter, the total pore volume hardly changes because the skeletal phase is thick. If the total pore volume is less than 0.5 ml / g, the amount of permeated liquid and the amount of permeated gas per unit cross-sectional area will be reduced, and the processing capacity will be reduced. On the other hand, if the total pore volume exceeds 5 ml / g, the catalytic activity is lowered, which is not preferable. Note that the total pore volume of the composite monolith (monolith intermediate, composite monolith, composite monolith ion exchanger) is the same both in the dry state and in the water wet state.

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

  In the composite monolith ion exchanger of the present invention, the ion exchange groups are uniformly introduced to the surface of the porous body and the inside of the skeleton, and the ion exchange capacity is 1 to 5 mg equivalent / g dry porous body, preferably 3 ~ 5 mg equivalent / g dry porous material. 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 in order to increase the exchange capacity per volume. In addition, since the opening diameter is reduced, the pressure loss increases. In contrast, the monolith ion exchanger of the present invention can further increase the opening diameter and thicken the skeleton of the continuous macropore structure (thicken the skeleton wall). Moreover, since the contact area with the fluid increases due to the presence of particles on the surface of the skeleton, the catalytic activity can be dramatically increased while the pressure loss during permeation is kept low. 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 composite monolith of the present invention include cation exchange groups such as a sulfonic acid group, a carboxylic acid group, an iminodiacetic acid group, a phosphoric acid group, and a phosphoric acid ester group.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  There is no restriction | limiting in particular as a method of introduce | transducing a cation exchange group into the said composite 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 composite monolith is a styrene-divinylbenzene copolymer, etc., a method of sulfonation using chlorosulfuric acid, concentrated sulfuric acid, or fuming sulfuric acid; radical initiating groups uniformly on the composite monolith And a method of grafting sodium styrene sulfonate or acrylamido-2-methylpropane sulfonic acid by introducing a chain transfer group into the skeleton surface or inside the skeleton; Similarly, after graft polymerization of glycidyl methacrylate, the sulfonic acid group is converted by functional group conversion. The method etc. which introduce | transduce are mentioned. Among these methods for introducing sulfonic acid groups, the method of introducing sulfonic acid groups into a styrene-divinylbenzene copolymer using chlorosulfuric acid is preferable because ion exchange groups can be introduced uniformly and quantitatively. Examples of ion exchange groups to be introduced include cation exchange groups such as carboxylic acid groups, iminodiacetic acid groups, sulfonic acid groups, phosphoric acid groups, and phosphoric acid ester groups.

  The solid acid catalyst of the present invention can be used for organic reactions such as esterification and ester hydrolysis. In particular, the reaction product is continuously reacted while the supplied reaction raw materials are reacted in a reactive distillation column. Use in a reactive distillation method that takes out the difference in boiling point outside the system, while maintaining sufficiently high catalytic activity, dramatically improves the permeability of gases and liquids consisting of raw materials or products, or mixtures thereof. It is suitable at the point which can be improved to.

  The form of packing the solid acid catalyst of the present invention into the reaction tower is not particularly limited, for example, a method of packing a product produced according to the shape in the reaction tower as it is, dividing into a plurality of block shapes, A method of laminating and filling, a method of incorporating a layer using a conventional granular cation exchange resin in part, and the like can be mentioned. Furthermore, it can be filled with a processed product of the solid acid catalyst and the support member of the present invention. In this case, the support strength of the solid acid catalyst in the reaction tower is increased, and the solid acid catalyst can be used even when the liquid passing speed in the reaction tower is high.

(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.

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

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

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

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

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

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

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

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

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

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

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

Comparative Examples 2-4
(Manufacture of monoliths)
The amount of vinyl monomer used, the amount of crosslinking agent used, the type and amount of organic solvent used, the porous structure of the monolith intermediate that coexists during polymerization in step III, the crosslinking density, and the amount used were changed to the amounts shown in Table 1. Produced a monolith in the same manner as in Example 1. The results are shown in Tables 1 and 2. In Comparative Example 2, the crosslinking density ratio (0.2 times), in Comparative Example 3, the type of organic solvent (2- (2-methoxyethoxy) ethanol; molecular weight 120), and in Comparative Example 4, the polymerization temperature (50 C .: 1 ° C. lower than the 10-hour half-life temperature of the polymerization initiator) was produced under conditions that did not satisfy the production conditions of the present invention. The results are shown in Table 2. For the monoliths of Comparative Examples 2 and 4, there was no particle formation on the skeleton surface. In Comparative Example 3, the isolated product was transparent, and the porous structure was collapsed and disappeared.

(Production of monolith cation exchanger)
Except for Comparative Example 3, the organic porous material produced by the above method was reacted with chlorosulfuric acid in the same manner as in Comparative Example 1 to produce a monolith cation exchanger. The results are shown in Table 2. The obtained monolith cation exchanger had an ion exchange zone length of 23 to 26 mm, which was a larger value than Examples 1 to 5.

Comparative Example 5
(Production of monolithic organic porous cation exchanger (known product))
27.7 g of styrene, 6.9 g of divinylbenzene, 3.8 g of sorbitan monooleate and 0.14 g of azobisisobutyronitrile were mixed and dissolved uniformly. Next, the styrene / divinylbenzene / sorbitan monooleate / azobisisobutyronitrile 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 an 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. 30 g of a porous material containing 14 mol% of a cross-linking component composed of a styrene / divinylbenzene copolymer thus obtained was fractionated, 2 liters of tetrachloroethane was added, and the mixture was heated at 60 ° C. for 30 minutes. After cooling, 120 g of chlorosulfuric acid was gradually added and reacted at room temperature for 4 hours. Then, 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. As a result of observation by SEM, the internal structure of this porous body has an open-cell structure. Most of the macropores having an average diameter of 30 μm overlap, and the average value of the diameters of the mesopores formed by the overlap of the macropores and the macropores. Was 5 μm and the total pore volume was 10.1 ml / g. Further, the porous body was cut into a thickness of 10 mm, and the water permeation rate and the air permeation rate were measured to be 14,000 L / min · m ² · MPa and 3,600 m ³ / min · m ² · MPa, respectively. It was. The ion exchange zone length was 41 mm.

<Evaluation test of solid acid catalyst>
(Hydrolysis reaction of methyl acetate by reactive distillation (Part 1)
A jacketed column with an inner diameter of 25 mm is used as a reactive distillation column, and a lower part is filled with a glass helix with a diameter of 4 mm over a height of 800 mm to form a recovery part. The porous cation exchanger obtained in Example 2 is provided on the upper part. Was cut into a size of 25 mm in diameter and 800 mm in height and filled as a solid acid catalyst to form a reaction part. The filling amount was 27.5 g in dry weight. A methyl acetate / methanol mixture (molar ratio 1.0 / 0.4) is supplied to the reactive distillation column from the lower end of the reaction section at a rate of 100 g / hour, while water is supplied from the upper end of the reaction section to 100 g / hour. The reaction was carried out at a rate of In addition, all the supplied liquids were heated to 65 ° C. and supplied, 65 ° C. warm water was circulated through the jacket of the reactive distillation column, and the liquid in the still was heated to 85 ° C. and operated at total reflux. When the hydrolysis rate (reaction rate) was measured after the reaction was stabilized, an average reaction rate of 99.3% was obtained. In addition, when the water permeation rate and the air permeation rate of the composite monolith ion exchanger of Example 2 were measured, they were 110,000 L / min · m ² · MPa and 28,000 m ³ / min · m ² · MPa, respectively. Good permeability was shown.

(Methyl acetate hydrolysis by reactive distillation (Part 2))
Hydrolysis reaction of methyl acetate by reactive distillation (Part 1), except that the porous cation exchanger obtained in Comparative Example 5 was used instead of the porous cation exchanger obtained in Example 2 The same method was used. As a result, an average reaction rate of 97% was obtained.

  In the reaction of the solid acid catalyst, when the contact efficiency represented by the ion exchange zone length is improved, the reaction efficiency is improved. As described above, the length of the ion exchange zone is 8 to 12 mm in Examples 1 to 5, and 23 to 41 mm in Comparative Examples 1 to 5. As a result, the reaction rate of the example product was better than that of the comparative example product. The difference between the reaction rate of 97% and 99.3% is a reduction from 3% to 0.7%, that is, a reduction rate of 77% when viewed from the remaining amount of unreacted raw materials. This is a remarkable effect.

  According to the solid acid catalyst of the present invention, an organic reaction can be efficiently advanced in a short time and at a high reaction rate, and it is widely used as a solid acid catalyst for reactive distillation as well as a normal organic reaction process. It can be applied in application fields.

Claims (4)

  An organic porous body composed of a continuous skeleton phase and a continuous pore phase, and a large number of particles having a diameter of 4 to 40 μm fixed to the skeleton surface of the organic porous body or the skeleton surface of the organic porous body It is a composite structure with many protrusions having a size of 4 to 40 μm, and has an average pore diameter of 10 to 150 μm, a total pore volume of 0.5 to 5 ml / g in a wet state, and a cation exchange capacity. A solid acid catalyst comprising a monolithic organic porous cation exchanger which is 1 to 5 mg equivalent / g dry porous material.   2. The solid acid according to claim 1, wherein the organic porous body is a continuous macropore structure in which bubble-shaped macropores overlap each other, and the overlapping portion forms an opening having an average diameter of 30 to 150 μm when wet. catalyst.   The organic porous body is a three-dimensionally continuous skeleton having an average thickness of 1 to 60 μm in a water-wet state, and a three-dimensionally continuous skeleton having an average diameter of 10 to 100 μm in a water-wet state between the skeletons. 2. The solid acid catalyst according to claim 1, which is a co-continuous structure comprising pores.   The solid acid catalyst according to any one of claims 1 to 3, wherein the solid acid catalyst is used in a reactive distillation method.