JPH10245416A - Porous, strongly basic anion exchanger and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject porous exchanger having excellent thermal resistance, by making the exchanger include two kinds of specific structural units, and setting the specific area within a specified range. SOLUTION: This exchanger is obtained by including 5-99(mol)% structural unit having a quaternary ammonium salt group of formula I A is a 3-8C straight chain alkylene, etc.; R<1> is an (OH-substituted) 1-4C alkyl; R<2> and R<3> are each a 1-4C hydrocarbon; X<-> is a counter ion coordinated to the ammonium group; the benzene ring may be substituted with an alkyl, etc.}, and 0.5-60(mol)% structural unit derived from a crosslinkable monomer containing an unsaturated hydrocarbon group, and setting the specific area at 1-500m<2> /g, and setting, preferably, the neutral salt group exchanging capacity per weight and an ion exchanging capacity per volume as 1.0-6.0meq/g and 0.1-2.1meq/ml, respectively. This exchanger is obtained by using, as a porosifying agent, an organic solvent having a difference between its C LogP value and that of a precursor monomer composed of structural unit of formula II (Z is a halogen, OH, etc.) of >=1.7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel porous strong basic anion exchanger and a method for producing the same.
It relates to a porous strong basic anion exchanger having excellent heat resistance.

[0002]

2. Description of the Related Art Heretofore, a porous ion-exchange tree produced from a copolymer of styrene and divinylbenzene has been known. In U.S. Pat. No. 4,256,840 and U.S. Pat. No. 4,501,826, tert-porous agent is used as a porogen when polymerizing a copolymer of styrene and divinylbenzene.
After obtaining a copolymer in the presence of amyl alcohol, an anion exchange group and a cation exchange group are introduced to obtain an ion exchanger. There are many types of monomers and porogens used at this time, but no index for selecting a porogen in forming a porous body is clearly shown.
For this reason, when trying to obtain a porous ion exchanger, it was necessary to select the type of the porogen based on trial and error.

On the other hand, JP-A-4-349951 and JP-A-7-289912 disclose heat-resistant, strongly basic anion exchangers. There is no suggestion about a porosity agent that can be used only when the porosity of these resins is only a mold.

[0004]

Accordingly, there has been a need for an anion exchanger having porosity and excellent heat resistance.

[0005]

Means for Solving the Problems The present inventors have studied a porosity agent which can be used when making a strongly basic anion exchanger having heat resistance porous, and as a result, the above claim 2 has been obtained.
It has been found that the porous agent described in (1) has a heat resistance and a porous, strongly basic anion exchanger can be obtained, thereby completing the present invention.

That is, the present invention comprises a structural unit having a quaternary ammonium group represented by the following general formula (I) and a structural unit derived from an unsaturated hydrocarbon group-containing crosslinkable monomer and having a specific surface area of 1 A porous strong basic anion exchanger that is ５００500 m ² / g;

[0007]

Embedded image

(In the general formula (I), A represents a linear alkylene group having 3 to 8 carbon atoms or an alkoxymethylene group having 4 to 9 carbon atoms, and R ¹ represents a carbon number which may be substituted by a hydroxyl group. An alkyl group of 1 to 4, R ² and R ³ are a hydrocarbon group having 1 to 4 carbon atoms, X ⁻ is a counter ion coordinated to an ammonium group, and the benzene ring is substituted with an alkyl group or a halogen atom. May be.)

Further, as a porogen, the following general formula (I)
2. The porous solid according to claim 1, wherein one or more organic solvents having a difference from the CLogP value of the precursor monomer of the structural unit represented by I) of about 1.7 or more are used. The present invention relates to a method for producing a basic anion exchanger.

[0010]

Embedded image

(In the general formula (II), A has the same meaning as in the general formula (I), and Z is a halogen atom, a hydroxyl group, a tosyl group or NR ¹ R ² (R ¹ and R ² are the same as those in the general formula (I) )
And synonymous with). )

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The porous strong basic anion exchanger of the present invention is derived from a structural unit having a quaternary ammonium group represented by the general formula (I) according to claim 1 and an unsaturated hydrocarbon group-containing crosslinkable monomer. Contains structural units.

In the general formula (I), A represents 3 to 8 carbon atoms.
Represents a linear alkylene group or an alkoxymethylene group having 4 to 9 carbon atoms. Examples of the linear alkylene group include a propylene group, a butylene group, a pentylene group, and a hexylene group. Examples of the alkoxymethylene group include a butoxymethylene group and a pentoxymethylene group.

If A does not have 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, so that sufficient heat resistance cannot be obtained, and Degree decreases. Regarding the decrease in basicity, the fact that an aliphatic amine has a higher basicity than an anion is sufficiently expected. On the other hand, when A is a long chain such as a nonylene group, the molecular weight of the structural unit per ion exchange group increases, and as a result, the ion exchange capacity per unit weight decreases, which is disadvantageous as an ion exchanger.

A is structurally the m- of a styrene residue.
It is preferably introduced at the position or the p-position. Even when introduced at the o-position, a benzene ring and a substituent (ANR ¹ R
² ) is considered to have little steric effect, but in consideration of steric hindrance upon copolymerization with a crosslinking agent, A is m-
It is preferably introduced at the position or the p-position.

In the general formula (I), R ¹ represents an alkyl group having 1 to 4 carbon atoms which may be substituted by a hydroxyl group, and these alkyl groups include a methyl group, an ethyl group, a propylene group and a butylene. And the like. R ² and R ³ represent a hydrocarbon group having 1 to 4 carbon atoms, and examples thereof include an alkenyl group and the like in addition to the above-described alkyl groups.

In the present invention, from the viewpoint of minimizing the decrease in the exchange capacity per unit weight, R ¹ , R
^A trimethylammonium base in which ² and R ³ are methyl groups (type I strong basic resin) or a dimethylhydroxyethyl ammonium base in which R ¹ is a hydroxyethyl group and R ² and R ³ are methyl groups (type II strong basic resin) Is preferred.

[0018] In the general formula (I), X ^- as is, specific examples is a counter ion coordinated to an ammonium ^{group, Cl -, Br -, I} - halogen ion, sulfate ion, such as, NO3 ^-, Examples of the anion include OH ^- and p-toluenesulfonic acid ion, and when the anion is divalent like sulfate ion, one anion molecule per two structural unit molecules represented by the general formula (I) Join.

In the general formula (I), the benzene ring may be substituted with the above-mentioned alkyl group or a halogen atom such as chlorine, bromine, iodine and the like.

The unsaturated hydrocarbon group-containing crosslinkable monomer which is a constituent unit of the porous strong basic anion exchanger of the present invention includes divinylbenzene, trivinylbenzene, divinyltoluene, divinylnaphthalene, divinylxylene, ethyleneglycoldiene. Examples include methacrylate, diethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate. Among these,
Divinylbenzene is preferred.

In the porous strong 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 crosslinkable 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 crosslinkable monomer is too small. Has a high swelling property and not only decreases the ion exchange capacity per unit volume, but also makes it difficult for pores to develop. Therefore, the ratio of each of the above structural units is appropriately selected in consideration of ion exchange capacity, swellability, strength and the like.

In the present invention, the proportion of the structural unit (precursor monomer) represented by the general formula (I) in the total structural units (precursor total monomers) constituting the strong basic anion exchanger is usually 5 to 5. The content of the structural unit (precursor monomer) derived from the unsaturated hydrocarbon group-containing crosslinkable monomer is 99 mol%, preferably 50 to 98 mol%.
Usually 0.5 to 60 mol%, preferably 2 to 50 mol%
Range.

The neutral base exchange capacity per weight of the strong basic anion exchanger of the present invention is usually 1.0 to 6.0.
meq / g, preferably in the range of 1.0 to 5.5 meq / g, and the ion exchange capacity per volume varies depending on the water content, but is usually in the range of 0.1 to 2.1 meq / ml. Here, meq / g represents a milliequivalent per dry resin weight, and meq / ml represents a milliequivalent per hydrated resin volume.

Next, a method for producing the porous strong basic anion exchanger of the present invention will be described. The porous strong basic anion exchanger of the present invention comprises a precursor of the structural unit represented by the general formula (II) and an unsaturated hydrocarbon group-containing crosslinkable monomer, according to a known ion exchanger production technique. It can be produced by subjecting suspension polymerization in the presence of a polymerization initiator and, if necessary, introducing a strong base anion exchange group into the obtained spherical crosslinked polymer.

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 is a halogen atom such as chlorine, bromine or iodine, a hydroxyl group, a tosyl group (toluenesulfonic acid group) or NR ¹ R ² (R ¹ and R ² have the same meaning as in the above formula (I)).

The above general formula (I) wherein A is an alkylene group
The precursor monomer (alkyl spacer type monomer) of the structural unit represented by I) can be synthesized by a known method. For example, a Grignard reagent is obtained by reacting halogenated styrene (chlorostyrene, bromostyrene, etc.), chloromethylstyrene (which may be a mixture of m and p forms) or vinylphenethyl halide with metal magnesium,
Coupling with 1, ω-dihalogenoalkane.

At the time of 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 in order to carry out the reaction efficiently. . In addition, the alkyl spacer type monomer,
The ω-halogenoalkylbenzene derivative can also be synthesized by acetylating and then introducing a vinyl group.

The precursor monomer (ether spacer type monomer) of the structural unit represented by the general formula (II) wherein A is an alkoxymethylene group can also be synthesized by a known method. For example, it can be synthesized by a method of converting a vinylbenzyl alcohol and a 1, ω-dihalogenoalkane into a halogenoalkoxymethylstyrene derivative.

In the present invention, the suspension polymerization is performed on a suspension solution containing a precursor monomer of the structural unit represented by the general formula (II), an unsaturated hydrocarbon group-containing crosslinkable monomer, and a porogen. However, at this time, a third monomer component may be used as a copolymer component, if necessary, as long as the function of the porous strong basic anion exchanger of the present invention is not reduced.

Examples of the third copolymer component include styrene, alkylstyrene, polyalkylstyrene, (meth) acrylic acid ester, (meth) acrylic acid, acrylonitrile, and the like. Is usually at most 50 mol%, preferably at most 20 mol%, based on the total amount of the essential monomers of the formula (1). In addition, bisvinylphenylethane, bisvinylbenzyl ether, bisvinylphenylbutane, and the like, 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.

The porogen used in the production of the porous strong basic anion exchanger of the present invention is represented by the general formula (I)
One or more organic solvents having a difference from the CLogP value of the precursor monomer of the structural unit represented by I) of about 1.7 or more can be used. The CLogP value was developed by the University of Pomona, California, USA, and is a value obtained by calculating the logarithm of the partition coefficient of a solute in a 1-octanol / water system. In the case of a mixed solvent, CLo
The gP value is an average value of the sum of the respective values. Note that CLo
Details regarding the gP value are described in JP-A-6-126195.

The ClogP value of styrene, which is a monomer generally used for producing an ion exchanger, is 2.87. An organic solvent that can be used as a porogen when styrene is used is a good solvent for the copolymer composed of the monomer used in the present invention, and pores may not be sufficiently developed. Specifically, in the case of styrene, isooctane used as a porogen is a copolymer composed of a monomer represented by A = (CH ₂ ) ₄ and Z = Cl in the general formula (II) of the present invention. Does not act as a porogen. In the general formula (II) of the present invention, A =
(CH ₂ ) ₄ , ClogP of a monomer represented by Z = Cl
The value is 4.67. On the other hand, the ClogP value of isooctane is 4.54. Further, as shown in the examples described later, C
Isoamyl alcohol having a LogP value of 1.22, CL
2-ethylhexyl alcohol having an ogP value of 2.81 also acts as a porogen in the present invention. Also,
It is preferable to select an organic solvent having a large difference between the monomer represented by the general formula (II) and the CLogP value.

Specific examples of preferred porogens in the present invention include 1,2-dichloroethane, 1,1-dichloroethane, tetrachloromethane, trichloromethane, dichloromethane, hexane, heptane, octane, nonane,
Cyclohexane, decane, dodecane, decalin, 2-methylhexane, 3-methylhexane, 2,4-dimethylpentane, 2,2,4-trimethylpentane, 2,2,2
5-trimethylhexane, butylbenzene, toluene,
Chlorobenzene, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1
-Pentanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 2-methyl-1-butanol, iso-amyl alcohol, tert-amyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 1-octanol, 2-ethyl-1-hexanol, benzyl alcohol, cyclohexanol,
-Methyl-2-pentanol, 3,5,5-trimethyl-1-hexanol, 2-butanone, 2-pentanone,
And cyclohexanone. Preferably, 2-ethylhexyl alcohol, iso-amyl alcohol,
4-methyl-2-pentanol.

In the present invention, it is necessary to use one or more porogens having a CLogP value within the above range, and an organic solvent having a CLogP value of less than 1.7 is mixed with this. It is also possible to use. In this case, the mixing ratio is preferably such that the organic solvent having a CLogP value of less than 1.7 by weight is about 50% or less. The amount of the porogen used may be an amount sufficient to impart porosity to the produced copolymer, and is appropriately selected depending on the ratio of the crosslinking monomer to the total amount of the monomers and the type of the porogen used. Yes, but generally, based on the total amount of monomers,
0.1 to 200% by weight is used.

As the polymerization initiator to be added at the time of polymerization, benzoyl peroxide (BPO), lauroyl peroxide, t-butyl hydro-peroxide, azobisisobutyronitrile (AIBN) and the like are used. 0.1 to 20% by weight, preferably about 0.5 to 5% by weight. The polymerization temperature at that time varies depending on the type and concentration of the polymerization initiator, but is usually selected in the range of 40 to 100 ° C.

At the time of suspension polymerization, it is also possible to add a dispersant, a suspending agent and a pH adjuster to the reaction system in addition to the porogen and the polymerization initiator. Gelatin,
Carboxymethyl cellulose, polyvinyl alcohol,
Sodium poly (meth) acrylate, poly (diallyldimethylammonium chloride) and the like are added. Also, p
As an H adjustor, NaOH, boric acid, borate, phosphate, sodium bicarbonate and the like are used, and sodium chloride,
Inorganic salts such as sodium sulfate and calcium chloride are also used.

The copolymers obtained as described above are disclosed in JP-A-4-34991 and JP-A-7-28991.
The porous strong basic anion exchanger of the present invention can be obtained by introducing an ammonium group according to the method described in JP-A No. 2 and then changing the salt type to various anion types by a known method.

The porous strong basic anion exchanger of the present invention is a porous body having pores therein, and has a specific surface area of:
1 to 500 m as measured by the nitrogen adsorption method by the BET method
² / g, preferably 10 to 40 m ² / g. The pore volume is 0.1 to 1.5 ml / mer by mercury penetration method.
g, preferably 0.2 to 1.2 ml / g. In addition,
The ion exchanger of the present invention, in addition to the particulate, lump,
Powders, fibers and any other shapes are included.

The porous strong basic anion exchanger of the present invention is used for various applications, and is used for general applications where an ion exchanger is used.

The ion exchanger is suitably used for water treatment applications, particularly for desalination of water. The desalting method is performed by bringing the anion exchanger obtained in the present invention into contact with water or an aqueous solution. The contacting method employs a conventional water treatment method, for example, a batch type, semi-batch type, continuous type or semi-continuous type method using a fluidized bed, a stirred tank, a batch tank, a cocurrent or countercurrent column. . At this time,
Since it has excellent heat resistance, it can be used for treating hot water and hot water. Further, it can be used as a basic catalyst. The porous type has a larger surface area than the gel type, and thus may be advantageous in terms of accelerating the reaction rate. When used as a catalyst, it can also be used for reactions in high-temperature regions that could not be used before because of its excellent heat resistance.

Further, since it is porous, it has excellent resistance to organic contamination, and its function lasts for various uses.

[0042]

The present invention will be described more specifically with reference to the following examples. In the following description, the specific surface area is BE
The average pore radius and the pore volume were measured by a nitrogen adsorption method by the T method, and the mercury thickening method. The ion exchange capacity was measured according to the Diaion Manual (issued by Mitsubishi Chemical Corporation) (meq / g represents a milliequivalent per dry resin weight).

Example 1 49.1 g of 4-chlorobutylstyrene and 4.6 g of high-purity divinylbenzene (purity: 81.5%, Nippon Steel Chemical Co., Ltd., degree of crosslinking: 10 mol%) were mixed, and 2-ethylhexyl alcohol was further added. (51.68 ml) 43.0 g, after dissolving AIBN as a polymerization initiator, dispersing in deionized water in which polyvinyl alcohol and sodium sulfate were dissolved, and then 7
Polymerization was carried out at 0 ° C. for 6 hours and further at 100 ° C. for 2 hours. After the polymerization, the copolymer was taken out and washed with methanol. When the specific surface area of the obtained copolymer was measured, it was 26.3 m.
² / g.

Example 2 49.1 g of 4-chlorobutylstyrene and 4.6 g of high-purity divinylbenzene (crosslinking degree: 10 mol%) were mixed, and 41.8 g of (iso-amyl alcohol) 3-methyl-1-butanol was added. After dissolving BPO as a polymerization initiator, the resultant was dispersed in deionized water in which gelatin and sodium sulfate were dissolved, and then polymerized at 80 ° C for 6 hours and further at 100 ° C for 2 hours. After the polymerization, the copolymer was taken out and washed with methanol. When the specific surface area of the obtained copolymer was measured,
It was 18.8 m ² / g.

Comparative Example 1 49.1 g of 4-chlorobutylstyrene and divinylbenzene
4.6 g (crosslinking degree: 10 mol%)
Dissolve 35.8 g of octane and BPO as a polymerization initiator
After that, hydroxyethyl cellulose is dissolved in demineralized water
Dispersed at 70 ° C for 6 hours and further at 100 ° C for 2 hours.
I combined. After polymerization, remove copolymer and wash with methanol
did. When the specific surface area of the obtained copolymer was measured,
0.8m ^Two/ G and the pore structure is not sufficiently developed
I confirmed that

Comparative Example 2 49.1 g of 4-chlorobutylstyrene and 4.6 g of divinylbenzene (crosslinking degree: 10 mol%) were mixed, 65.0 g of dichloroethane and BPO as a polymerization initiator were dissolved, and then hydroxyethyl cellulose was dissolved. The mixture was dispersed in the desalted water and polymerized at 70 ° C. for 6 hours and further at 100 ° C. for 2 hours. After the polymerization, the copolymer was taken out and washed with methanol. The specific surface area of the obtained copolymer could not be measured. It was also confirmed that the pore structure was not sufficiently developed.

Example 3 As shown in Table 1, 4-chlorobutylstyrene, divinylbenzene, and 4-methyl-2-pentanol were mixed in appropriate amounts to prepare copolymers having different degrees of crosslinking. However, AIBN was used as the polymerization initiator, and demineralized water in which gelatin and PAS-A (diallyldimethylammonium chloride-sulfur dioxide copolymer, manufactured by Nitto Boseki Co., Ltd.) were dissolved was adjusted to pH with sodium nitrite and boric acid. After dispersing the monomer mixture in 9.5 to 10.5,
Polymerization was carried out for 8 hours. The obtained copolymer was prepared from methanol, T
It was washed with HF and methylene chloride in that order. The obtained copolymer was mixed with 80 ml of methanol and 240 ml of a 30% aqueous solution of trimethylamine in a closed reactor for 4 hours for 8 hours.
By heating to 0 ° C., an ion exchange resin having a trimethylammonium group was obtained. Table 1 shows the ion exchange capacity and the specific surface area.

[0048]

[Table 1]

Example 4 A mixture of 22 g of 4-bromobutoxymethylstyrene and 1.3 g (purity: 55%) of divinylbenzene was added, and an equal amount of a mixture of 4-methyl-2-pentanol and n-octane was added. The polymerization initiator uses AIBN, gelatin,
Desalted water in which PAS-A (diallyldimethylammonium chloride-sulfur dioxide copolymer, manufactured by Nitto Boseki Co., Ltd.) is dissolved, and the pH is adjusted to 9.5 with sodium nitrite and boric acid.
After the monomer mixture was dispersed in the mixture adjusted to １10.5, polymerization was carried out at 70 ° C. for 18 hours. Table 2 shows that 4-methyl-
Shows the ratio of 2-pentanol to isooctane.

The obtained porous copolymer was washed with methanol, THF, and methylene chloride in this order, and filtered.
It was dried under reduced pressure. 20 g of the dried resin is mixed with 1,4-dioxane 2
After swelling in 00 ml for 1 hour, 200 ml of a 30% aqueous solution of trimethylamine was added dropwise and reacted at 50 ° C. for 15 hours to obtain an ion exchange resin having a trimethylammonium group. Table 2 shows the pore properties of the obtained ion exchange resin.

[0051]

[Table 2]

[0052]

According to the present invention, it has porosity,
A strongly basic anion exchanger having excellent heat resistance can be obtained.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 212: 36) (C08F 212/14 220: 26)

Claims (2)

[Claims] 1. A composition comprising a structural unit having a quaternary ammonium group represented by the following general formula (I) and a structural unit derived from an unsaturated hydrocarbon group-containing crosslinkable monomer, and having a specific surface area of 1 to 500 m ^2. / G of a porous strong basic anion exchanger. Embedded image (In the general formula (I), A represents a linear alkylene group having 3 to 8 carbon atoms or an alkoxymethylene group having 4 to 9 carbon atoms,
R ¹ is an alkyl group having 1 to 4 carbon atoms which may be substituted with a hydroxyl group, R ² and R ³ are a hydrocarbon group having 1 to 4 carbon atoms,
X ^- is a counter ion coordinated to an ammonium group, and the benzene ring may be substituted with an alkyl group or a halogen atom. ) 2. As the porogen, use is made of one or more organic solvents whose difference from the ClogP value of the precursor monomer of the structural unit represented by the following general formula (II) is about 1.7 or more. The method for producing a porous strong basic anion exchanger according to claim 1, wherein Embedded image (In the general formula (II), A has the same meaning as the general formula (I), and Z is a halogen atom, a hydroxyl group, a tosyl group, or NR ¹ R
² (R ¹ and R ² have the same meanings as in the above formula (I)). )