JP3716056B2 - Weakly basic anion exchanger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a weakly basic crosslinked anion exchanger, particularly, the invention relates to a weakly basic crosslinked anion exchanger excellent novel structure and heat resistance.
[0002]
[Prior art]
In general, an anion exchange resin is produced by amination of a chloromethyl group of a chloromethylated styrene-divinylbenzene copolymer with an alkylamine from the viewpoint of chemical stability, strength, and production cost. As the weakly basic anion exchanger, an anion exchanger having a dimethylamino group or a polyalkylene polyamino group is mainly used.
[0003]
As an example other than the weakly basic anion exchanger having the benzylamine structure as described above, an anion exchanger having an ethylene chain (ethylbenzene structure) has been reported (JP-A 61-27403, J. Org. Chem., 2270 (1986) However, a weak base anion exchanger having an ethylene chain structure has a disadvantage of poor heat resistance.
[0004]
On the other hand, a weakly basic anion exchanger having an alkylene group having 1 to 4 carbon atoms as a linking group (spacer) between an anion exchange group and a resin matrix is known (Japanese Patent Publication No. 7-57320). The weakly basic anion exchanger described above is characterized in that it is essential to bind a long-chain alkyl having 9 to 30 carbon atoms to an amino group, and in particular, a film-like product has a low electric resistance. However, a weakly basic anion exchanger having such a structure is not always sufficient in terms of ion exchange capacity, elution components, heat resistance, and the like.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and its object is excellent in heat resistance, little elution from the polymer, to provide an excellent novel weakly basic crosslinked anion exchanger in reaction rate is there.
[0006]
[Means for Solving the Problems]
As a result of various studies to achieve the above object, the present inventors have obtained the following novel findings. That is, the present applicant previously provided a quaternary amino group having an ether-type spacer having a relatively long structure between the anion exchange group and the resin matrix as a strongly basic anion exchanger particularly excellent in heat resistance. A strongly basic anion exchanger having a structure in which the number of carbon atoms of the alkyl group bonded to is shortened to 1 to 4 has been proposed (JP-A-7-289921). In addition, as described above, the use of a strongly basic anion exchanger having an alkyl type spacer having a relatively long structure and having a structure in which the number of carbon atoms of an alkyl group bonded to a quaternary amino group is as short as 1 to 8 Proposed (JP-A-5-49949).
[0007]
By the way, the above strongly basic anion exchanger has excellent heat resistance on the premise of a structure having a quaternary amino group, but a weakly basic anion exchanger having a secondary amino group or a tertiary amino group. If the spacer between the anion exchange group and the resin matrix is made relatively long and the number of carbon atoms of the alkyl group bonded to the amino group is shortened, the above strongly basic anion exchanger is surprisingly In addition to the above, the inventors have obtained a novel finding that it is excellent in heat resistance, has little elution from the polymer, and is excellent in reaction rate.
[0008]
The present invention has been completed based on the above findings, Abstract of its is derived from structural units and an unsaturated hydrocarbon group-containing crosslinkable monomer at least represented by the following general formula (I) Structure It exists in the weakly basic anion exchanger characterized by containing a unit.
[0009]
[Chemical 3]
[0010]
In general formula (I), A is an alkylene group having 3 to 8 carbon atoms, an alkoxymethylene group having 5 to 7 carbon atoms, R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 6 or less carbon atoms. Or a polyaminoalkyl group, and the benzene ring may be substituted with an alkyl group or a halogen atom.
[0011]
The weakly basic anion exchanger of the present invention comprises a suspension containing at least a precursor monomer of a structural unit represented by the following general formula (II) and an unsaturated hydrocarbon group-containing crosslinkable monomer as a polymerization initiator. It polymerizes in presence, and can manufacture by the method of introduce | transducing a weakly basic anion exchange group into the obtained spherical crosslinked polymer as needed .
[0012]
[Formula 4]
[0013]
In general formula (II), A has the same meaning as in general formula (I), and Z represents chlorine, bromine, iodine, hydroxyl group, tosyl group (toluenesulfonic acid group) or NR ¹ R ² group. . R ¹ R ² has the same meaning as in the general formula (I), and the benzene ring may be substituted with an alkyl group or a halogen atom.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail . The weakly basic anion exchanger of the present invention contains at least a structural unit represented by the general formula (I) and a structural unit derived from an unsaturated hydrocarbon group-containing crosslinking monomer.
[0015]
In the general formula (I), A as a spacer represents an alkylene group having 3 to 8 carbon atoms or an alkoxymethylene group having 5 to 7 carbon atoms. Specific examples of the alkylene group having 3 to 8 carbon atoms include Examples include a propylene group, a butylene group, a pentylene group, a hexylene group, and an octylene group. Specific examples of the alkoxymethylene group having 5 to 7 carbon atoms include a butoxymethylene group and a pentoxymethylene group. The alkylene group having 3 to 8 carbon atoms may be a branched alkylene group such as an isopropyl group and a t-butyl group in addition to the linear alkylene group as described above. When A is an alkylene group, a linear alkylene group having 3 to 8 carbon atoms is preferable, and a linear alkylene group having 3 to 6 carbon atoms is more preferable.
[0016]
When A does not satisfy the above definition, for example, when A is a short chain such as a methylene group or an ethylene group, the anion exchange group (NR ¹ R ² ) is affected by the benzene ring through the short chain, and as a result, Sufficient heat resistance cannot be obtained, and the basicity is lowered. The decrease in basicity is sufficiently predicted from the fact that aliphatic amines have higher basicity than aniline. On the other hand, when A is a long chain like a nonylene group, the molecular weight of the weak anion exchanger increases, and as a result, the ion exchange capacity per unit weight decreases.
[0017]
In addition, A is preferably introduced into the m-position or p-position of the styrene residue in production. Even when introduced at the o-position, the steric influence between the benzene ring and the substituent (ANR ¹ R ² ) is considered to be small, but in consideration of steric hindrance during copolymerization with the crosslinking agent, A is preferably introduced at the m-position or p-position.
[0018]
In the general formula (I), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a polyaminoalkyl group. Examples of the alkyl group having 6 or less carbon atoms include a methyl group, Examples of the polyaminoalkyl group having 6 or less carbon atoms include a diaminoethyl group, a 1,3-diaminopropyl group, a triaminobutyl group, and a 1,6-diaminohexyl group. It is done. As R ¹ and R ² , a methyl group is preferable from the viewpoint of minimizing a decrease in exchange capacity per unit weight.
[0019]
Examples of the alkyl group that is a substituent of the benzene ring include a methyl group and an ethyl group, and examples of the halogen atom include fluorine, chlorine, bromine, and iodine.
[0020]
Examples of unsaturated hydrocarbon group-containing crosslinking monomers include divinylbenzene, polyvinylbenzene, alkyldivinylbenzene, dialkyldivinylbenzene, ethylene glycol (poly) (meth) acrylate, polyethylene glycol di (meth) acrylate, (poly) ethylenebis ( Among them, divinylbenzene is preferable.
[0021]
In the weakly basic anion exchanger of the present invention, the ratio of the structural unit represented by the general formula (I) and the structural unit derived from the unsaturated hydrocarbon group-containing crosslinking monomer is not particularly limited. However, when the proportion of the structural unit represented by the general formula (I) is too small, the ion exchange capacity decreases, and when the proportion of the structural unit derived from the unsaturated hydrocarbon group-containing crosslinking monomer is too small, the ion exchange capacity is high. It becomes swellable and the ion exchange capacity per unit volume decreases. Therefore, the ratio of each structural unit is appropriately selected in consideration of ion exchange capacity, swelling property, strength, and the like.
[0022]
However, the proportion of the structural unit (precursor monomer) represented by the general formula (I) in the total structural unit (precursor total monomer) constituting the weakly basic anion exchanger is usually 5 to 99 mol%, preferably The proportion of the structural unit (precursor monomer) derived from the unsaturated hydrocarbon group-containing crosslinkable monomer is usually 0.1% to 50 mol%, preferably 0.2% to The range is 25 mol%.
[0023]
The weak base anion exchanger according to the present invention has a weak base exchange capacity per weight of usually 1.0 to 6.0 meq / g, preferably 1.0 to 5.5 meq / g. The ion exchange capacity varies depending on the water content, but is usually in the range of 0.1 to 2.1 meq / ml. Here, meq / g represents milliequivalent per dry resin weight, and meq / ml represents milliequivalent per hydrous resin volume.
[0024]
Next, the manufacturing method of the weak basic anion exchanger of this invention is demonstrated. The weakly basic anion exchanger of the present invention is obtained by suspension polymerization of a precursor monomer of the structural unit represented by the general formula (II) and an unsaturated hydrocarbon group-containing crosslinkable monomer in the presence of a polymerization initiator. Accordingly, it can be produced by introducing a weakly basic anion exchange group into the obtained spherical crosslinked polymer.
[0025]
The structural unit represented by the general formula (II) is a precursor of the structural unit represented by the general formula (I). In the general formula (II), A has the same meaning as in the general formula (I), and Z represents a chlorine, bromine, iodine, hydroxyl group, tosyl group (toluenesulfonic acid group) or NR ¹ R ² group. Represent. R ¹ R ² has the same meaning as in the general formula (I). The introduction of the weakly basic anion exchange group is required when Z is a substituent other than the NR ¹ R ² group.
[0026]
The precursor monomer (alkyl spacer monomer) of the structural unit represented by the general formula (II) in which A is an alkylene group can be synthesized, for example, by the following method. That is, a Grignard reagent is obtained by reaction of halogenated styrene (chlorostyrene, bromostyrene, etc.), chloromethylstyrene (may be a mixture of m and p isomers) or vinyl phenethyl halide with metal magnesium, Coupling with dihalogenoalkane.
[0027]
In the above coupling reaction, a catalyst such as copper halide (copper chloride, copper bromide, copper iodide), Li ₂ CuCl ₄ , amine or the like can be used for efficient reaction. The alkyl spacer type monomer can also be synthesized by a method of introducing a vinyl group after acetylating the ω-halogenoalkylbenzene derivative.
[0028]
The precursor monomer (ether spacer type monomer) of the structural unit represented by the general formula (II) in which A is an alkoxymethylene group can be synthesized, for example, by the following method. That is, it can be synthesized by a method of converting to a halogenoalkoxymethylstyrene derivative by reaction of vinylbenzyl alcohol and 1, ω-dihalogenoalkane.
[0029]
The suspension polymerization is carried out on a suspension solution containing a precursor monomer of the structural unit represented by the general formula (II) and an unsaturated hydrocarbon group-containing crosslinkable monomer. At this time, the weakly basic anion of the present invention is used. As long as the function of the exchanger is not reduced, the third monomer component may be used in combination as a copolymerization component, if necessary.
[0030]
Examples of the copolymer component include styrene, alkyl styrene, polyalkyl styrene, (meth) acrylic acid ester, (meth) acrylic acid, acrylonitrile, and the amount used is the sum of the above essential monomers. The amount is usually 50 mol% or less, preferably 20 mol% or less, based on the amount. Further, bisvinylphenylethane, bisvinylbenzyl ether, bisvinylphenylbutane, etc. which are by-produced when synthesizing the precursor monomer of the structural unit represented by the general formula (II) can also be used as a crosslinking agent.
[0031]
For suspension polymerization, a known suspension polymerization of water / oil type or oil / water type can be employed. At this time, the bath ratio is preferably adjusted to be in the range of 1 to 2 to 1 to 6. As the polymerization initiator, any polymerization initiator such as peroxide-based or azo-based can be used. Specifically, peroxide polymerization initiators such as benzoyl peroxide (BPO), lauroyl peroxide and t-butyl hydroperoxide, azoisobutyronitrile (AIBN), 2,2′-azobis (2, And azo polymerization initiators such as 4-dimethylvaleronitrile).
[0032]
The usage-amount of a polymerization initiator is 0.1-3 weight% normally with respect to the total amount of monomers. The polymerization temperature varies depending on the half-life temperature of the polymerization initiator, the content, the polymerizability of the monomer, and the like, but is usually in the range of 40 ° C to 150 ° C, preferably 50 ° C to 100 ° C. The polymerization time is usually 1 to 30 hours, preferably 1 to 15 hours.
[0033]
In suspension polymerization, various solvents may be added as necessary. The physical structure of the resulting crosslinked copolymer particles varies depending on the type and amount of the solvent to be added. Therefore, the desired crosslinked copolymer particles can be obtained by controlling the solvent used. That is, gel-type or porous-type crosslinked copolymer particles can be obtained.
[0034]
For example, when suspension polymerization is performed by adding an organic solvent such as toluene, hexane, isooctane or 2-ethylhexanol, which is a poor solvent, to the precursor monomer of the structural unit represented by the general formula (II), Depending on the content of the monomer in the turbid polymerization system, crosslinked copolymer particles having a porous structure can be obtained. On the other hand, when a good solvent such as tetrahydrofuran and 1,4-dioxane is added, swellable crosslinked copolymer particles are obtained. In addition, for example, water, methanol, ethanol, acetone or the like can be added as a solvent. The amount of such a solvent added is usually 100% by weight or less based on the total amount of all monomers.
[0035]
The particle size of the resulting crosslinked polymer particles varies somewhat depending on the use of the weakly basic anion exchanger. For example, when used as an ion exchange resin, the average particle diameter is usually in the range of 50 μm to 2 mm. When used as a catalyst resin, the average particle size is usually in the range of 20 μm to 1 mm.
[0036]
In the production method of the present invention, when Z in the general formula (II) is a substituent other than the NR ¹ R ² group, a weakly basic anion exchange group (NR ¹ R in the general formula (II) is represented by a known amination reaction. ² ) is introduced. As an aminating agent, for example, when Z is a halogen atom, ammonia (or an aqueous solution thereof), methylamine, dimethylamine (or an aqueous solution thereof), ethylenediamine, diethylenetriamine, 1,3-diaminopropane, 1,6-hexa Methylene diamine and polyalkylene polyamine can be used.
[0037]
In the above reaction, a solvent is usually added to the reaction system in order to swell the crosslinked polymer particles. Examples of the solvent include water, alcohols such as methanol, ethanol and propanol, hydrocarbons such as toluene and hexane, chlorinated hydrocarbons such as dichloromethane and 1,2-dichloroethane, dibutyl ether, dioxane and tetrahydrofuran. Ethers, dimethylformamide, acetonitrile, etc. are used.
[0038]
The reaction temperature varies depending on the reaction mode, the functional group and the type of solvent, but is usually in the range of 20 ° C to 130 ° C. In particular, when the functional group Z is a Cl atom, it is preferable to perform the reaction at a relatively high temperature because the functional group Z is inferior in detachability. In the above amination reaction, generally, the bulky amine molecule (the larger the molecular weight), the lower the ion exchange capacity of the weakly basic anion exchanger obtained.
[0039]
The weakly basic anion exchanger of the present invention is obtained as a sphere by the above suspension polymerization, but can also be made into a powder by subsequent pulverization. Furthermore, it can also be made into various shapes, such as a block shape, a fiber form, and a film | membrane form, by manufacturing by a solution polymerization method.
[0040]
In addition to the monomer method described above, the weakly basic anion exchanger of the present invention may be produced by a method in which a chloromethylated cross-linked copolymer is used as a raw material and a substituent A is introduced by a polymer modification method. I can do it. Specifically, there is a method in which a reagent such as n-BuLi is allowed to act on chloromethylated crosslinked polystyrene to generate a vinylbenzyl anion, and an alkyl spacer type crosslinked copolymer is obtained by reaction with 1, ω-dihalogenoalkane. Can be mentioned. The amino group can be introduced in the same manner as described above. However, the above-described monomer method is preferred from the viewpoint that the resulting weakly basic anion exchanger has a high ion exchange capacity.
[0041]
The weakly basic anion exchanger of the present invention can be used for various applications. Typical applications include purification of sugar liquid, separation / purification of weakly acidic substances, production of pure water, etc. in addition to general water treatment. Other applications include various adsorbents such as chromatographic carriers, membrane materials, catalyst carriers, phase transfer catalysts, enzymes, cells, and cell immobilization carriers. Since the weakly basic anion exchanger of the present invention is excellent in heat resistance, it is particularly advantageous for use at high temperatures. Furthermore, the weakly basic anion exchanger of the present invention has an advantage that the elution from the resin, which is a drawback of the anion exchanger, is small, and therefore there is almost no off-flavor, as will be apparent from the following examples. The utility value is high even at room temperature.
[0042]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to the following manufacture examples and Examples, unless the summary is exceeded.
[0043]
Example 1
<Synthesis of 4-bromobutylstyrene>
44 g of metal Mg and 360 g of tetrahydrofuran (THF) were placed in a 1 L four-necked flask equipped with a nitrogen gas introduction tube, a Jimroh cooling tube, a branched isobaric dropping funnel and a stirring blade, and the internal temperature was set to 36 ° C. To this flask, 350 ml of a THF solution of 251 g of p-chlorostyrene was added dropwise over 2 hours so that the internal temperature did not become 40 ° C. or higher, thereby preparing a Grignard solution of p-chlorostyrene. On the other hand, a mixed solution of 1060 g of 1,4-dibromobutane, 400 ml of THF, and 7.5 g of Li ₂ CuCl ₄ was prepared.
[0044]
The Grignard solution was dropped into the dibromobutane solution over 2 hours so that the internal temperature did not rise to 40 ° C. or higher. After the dropwise addition, the reaction was completed by stirring for 2 hours. The reaction solution was hydrolyzed with water and then separated. The organic phase was removed and THF was distilled off under reduced pressure. Furthermore, 4-bromobutyl styrene (a slightly yellowish transparent liquid, bp. 130 ° C./0.5 mmHg) was recovered by vacuum distillation.
[0045]
<Synthesis of 4-bromobutylstyrene cross-linked copolymer>
200 ml of demineralized water and 50 ml of 2% aqueous polyvinyl alcohol solution were added to a 500 ml four-necked flask equipped with a nitrogen gas inlet tube and a cooling tube, and nitrogen was introduced to remove dissolved oxygen. Meanwhile, 48.0 g of 4-bromobutylstyrene obtained by the above synthesis, 1.08 g of divinylbenzene (purity 100%) and 0.4 g of AIBN were dissolved to prepare a monomer solution, and dissolved oxygen was removed in the same manner as above. did.
[0046]
The obtained monomer solution was put into the above flask and stirred at 150 rpm to prepare a suspension. After stirring at room temperature for 30 minutes, the mixture was heated to 70 ° C. and stirred for 18 hours to carry out suspension polymerization to obtain a light yellow transparent spherical polymer. Subsequently, the obtained polymer was taken out, washed with water, and further washed with methanol three times. The polymerization yield was 93%, and the charged crosslinking degree of the polymer was 4 mol%.
[0047]
<Amination of 4-bromobutylstyrene cross-linked copolymer>
25 g of the above polymer was placed in a 500 ml four-necked flask equipped with a condenser, and 150 ml of methanol was added and stirred at room temperature. Subsequently, 108 g of 50% dimethylamine aqueous solution was added, and the reaction was performed at 50 ° C. for 8 hours to obtain an anion exchange resin. The obtained anion exchange resin was taken out and washed with water.
[0048]
Subsequently, in order to convert the counter ion of this anion exchange resin from bromide ion to chloride ion (Cl form), 10% amount of 4% sodium chloride aqueous solution was passed through the resin amount. The general performance of the Cl-type anion exchange resin (average particle size 750 μm) was measured. The results were as shown in Table 1.
[0049]
[Table 1]
[0050]
Example 2
In Example 1, an anion exchange resin was obtained in the same manner as in Example 1 except that 54 g of a 50% diethylenetriamine aqueous solution was used as the aminating agent. And it converted into Cl form and measured general performance. The results were as shown in Table 2.
[0051]
[Table 2]
[0052]
Example 3
<Synthesis of 4-chlorobutylstyrene>
In Example 1, except that 340 g of 1-bromo-4-chlorobutane was used instead of 1,4-dibromobutane, the same operation as in Example 1 was carried out, and 4-chlorobutylstyrene (transparent liquid, bp) was used. 112 ° C./0.2 mmHg).
[0053]
<Synthesis of 4-chlorobutylstyrene cross-linked copolymer>
In Example 1, except that 4-chlorobutylstyrene obtained in the above synthesis was used and the amount of divinylbenzene used was changed to 1.34 g, 4-chlorobutyl was operated in the same manner as in Example 1. A styrene crosslinked copolymer was obtained.
[0054]
<Amination of 4-chlorobutylstyrene cross-linked copolymer>
In Example 1, the anion exchange resin was obtained in the same manner as in Example 1 except that the above 4-chlorobutylstyrene crosslinked copolymer was used, the temperature was changed to 80 ° C., and the time was changed to 6 hours. . And it converted into Cl form and measured general performance. The results were as shown in Table 3.
[0055]
[Table 3]
[0056]
Example 4
<Synthesis of 4-bromobutoxymethylstyrene>
Sodium hydroxide 20 g (0.5 mol) and water 20 ml were added to a 300 ml four-necked flask and stirred to obtain a homogeneous solution. After returning the solution temperature to room temperature, 13.42 g (0.1 mol) of hydroxymethylstyrene (mixture of m-form and p-form), 32.39 g (0.15 mol) of 1,4-dibromobutane, tetrabutylammonium The bromide 3.22g (0.01mol) was melt | dissolved in 100 ml of toluene, and it put into said 4 necked flask. The mixed solution in the flask was reacted at 40 ° C. for 6 hours with stirring.
[0057]
After the reaction, the organic phase was separated and washed with water. Magnesium sulfate was added to the organic phase for drying, and then toluene was distilled off under reduced pressure. A solution obtained by vacuum distillation in the presence of DPPH (diphenylpicryl-2-hydrazyl) was used to obtain a colorless and transparent solution (b. p.112-117 ° C./0.6 mmHg). The structure of the obtained solution was confirmed by NMR. The yield of 4-bromobutoxymethylstyrene was 15.0 g, and the yield was 56%.
[0058]
<Synthesis of 4-bromobutoxymethylstyrene cross-linked copolymer>
In Example 1, 4-bromobutoxymethyl styrene obtained by the above synthesis was used, and the same procedure as in Example 1 was carried out except that the amount of divinylbenzene used was changed to 0.97 g. A styrene crosslinked copolymer was obtained.
[0059]
<Amination of 4-bromobutoxymethylstyrene cross-linked copolymer>
In Example 1, anion exchange was carried out in the same manner as in Example 1 except that the above 4-bromobutoxymethylstyrene crosslinked copolymer was used and 96 g of 1,3-propanediamine was used as the aminating agent. A resin was obtained. And it converted into Cl form and measured general performance. The results were as shown in Table 4.
[0060]
[Table 4]
[0061]
<Heat resistance test of weakly basic anion exchanger>
50 ml of the Cl-type anion exchange resin obtained in Example 1 was weighed, and 500 ml of 2N-sodium hydroxide aqueous solution was passed through to regenerate to OH type. Then, this regenerated resin was put into a glass autoclave tube, and deionized water of 0.8 times the volume of the OH resin was added. And nitrogen gas was passed for 60 minutes in the state heated at 50 degreeC in order to remove the dissolved oxygen in a container. The autoclave tube was immersed in an oil bath and allowed to stand at 140 ° C. for 30 days. Then, just in case, it regenerated | regenerated to OH type with 500 ml of 2N-sodium hydroxide aqueous solution. Furthermore, 5% of the resin amount of 4% sodium chloride aqueous solution was passed through to convert the counter ion X into Cl form.
[0062]
Changes in the volume and general performance of each Cl-type resin were measured. And the residual rate of the alkylene chain A in resin was calculated | required by the below-mentioned calculation formula. A symbol A in the calculation formula represents a neutral salt decomposition capacity (meq / ml), B represents a weak base exchange capacity (meq / ml), and C represents a Cl-form resin volume (ml). The results are shown in Table 5. The comparative resin in Table 5 is an anion exchange resin “Diaion WA-30” (registered trademark) manufactured by Mitsubishi Chemical Corporation.
[0063]
[Expression 1]
Residual rate (%) = [(A after test) × (C after test) ÷ (A before test) × (C before test)] × 100
[0064]
[Table 5]
[0065]
【The invention's effect】
The weakly basic anion exchanger of the present invention has excellent heat resistance, excellent chemical stability, little elution from the resin, and excellent reaction rate. It can be used for decolorization and separation / purification of weakly acidic substances. The weakly basic anion exchanger of the present invention can also be used as an anion exchange membrane and an anion exchange fiber in addition to an anion exchange resin.

Claims (3)

A weakly basic anion exchanger comprising at least a structural unit represented by the following general formula (I) and a structural unit derived from an unsaturated hydrocarbon group-containing crosslinking monomer.
  The weakly basic anion exchanger according to claim 1, wherein in the structural unit represented by the general formula (I), A is a linear alkylene group having 3 to 8 carbon atoms.   The unsaturated hydrocarbon group-containing crosslinkable monomer is divinylbenzene, and the proportion of the structural unit represented by the general formula (1) is 5 to 99 mol% in all the structural units, and the proportion of the structural unit derived from divinylbenzene is The weakly basic anion exchanger according to claim 1 or 2, which is 0.1 to 50 mol%.