JPH0722711B2 - Anion exchange resin and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an anion exchange resin having a novel structure and a method for producing the same, and more specifically to anions from a primary amino group to a quaternary ammonium group. The present invention relates to a production method in which an ion exchange group can be easily introduced without a chloromethylation (hereinafter referred to as CM) step, and an anion exchange resin produced by the method and having excellent chemical stability.

[Conventional technology]

Conventionally, as an anion exchange resin having a styrene unit, a general formula (3) or (4) is added to the aromatic ring of the cross-linked copolymer.
It is well known that a functional group represented by is bonded.

As a method of producing such an anion exchange resin, a method that has been widely performed conventionally is a method of converting crosslinked polystyrene into CM with chloromethyl methyl ether (hereinafter abbreviated as CME), and then reacting with amine to aminate. is there. Since CME used in this method contains bischloromethyl ether, a carcinogen, as an impurity, it is necessary to convert it into CM under strict control such as maintenance of working environment and treatment of waste liquid. I got it. In addition, when a heavy metal such as zinc chloride is used as a catalyst for commercialization, there is a problem that the heavy metal must be recovered after the catalyst is decomposed.

Several methods have been attempted as a method for producing an anion exchange resin that does not go through the CM process. For example, a method in which crosslinked polystyrene is reacted with allyl chloride or the like to introduce a chloroethyl group and then amination is carried out, but one having a sufficient exchange capacity has not been obtained. Cross-linked polystyrene is treated with N-methyl-N-chloromethylacetamide, N-methyloylacetamide,
Although a method of directly aminating with an aminating reagent such as N-chloromethylphthalimide has also been carried out, only a primary amine is mainly obtained by this method, and a tertiary amine,
In order to introduce a primary ammonium group, it is necessary to carry out a further alkylation reaction after amination, which has the drawback of lengthening the process. As a monomer, chloromethylstyrene (hereinafter abbreviated as CMS, also called vinylbenzyl chloride) instead of styrene is used, and after copolymerizing with a crosslinking agent, a method of aminating the obtained crosslinked polychloromethylstyrene is also performed. However, suspension polymerization using CMS is more difficult to control the polymerization process than when styrene is used, because the aqueous phase that is the dispersion medium becomes acidic, and it is difficult to obtain spherical polymers.

Functional groups [1] and [2] of the anion exchange resin according to the present invention
As an anion exchange resin having a functional group similar to that described above, an anion exchange resin obtained by reacting a crosslinked copolymer of glycidyl acrylate (meth) acrylate with an amine is known. However, since this resin has an ester structure in the skeleton structure, it has a drawback that it is susceptible to hydrolysis. In particular, it is weak against alkali, and a quaternary ammonium type strong basic resin obtained by reacting a crosslinked poly (meth) acrylic acid glycidyl ester with a tertiary amine causes self-hydrolysis when left in an aqueous solution. There was a big drawback that it would end up.

As described above, there is no known anion exchange resin which has been known to date and which has excellent chemical stability and can be easily produced.

[Object of the Invention]

An object of the present invention is to provide an anion exchange resin which is chemically stable and easy to produce, and a production method thereof. That is, it is intended to provide an anion exchange resin obtained by bonding an amino group or a quaternary ammonium group to a crosslinked polystyrene having excellent chemical stability without going through a CM formation step, and a method for producing the resin. is there.

[Structure of Invention]

The anion exchange resin of the present invention is an anion exchange resin obtained by bonding a functional group represented by the following general formula [1] or [2] to an aromatic ring of a crosslinked copolymer having a styrene unit.

(In the formula, m and n are integers of 0 to 6, and R ₁ , R ₂ and R ₃ represent hydrogen, an alkyl group or a hydroxyalkyl group.) The production method thereof is represented by the following general formula [3]. After copolymerizing a styrene derivative having a glycidyl group with a cross-linking agent, the glycidyl group of the resulting copolymer is reacted with ammonia or an amine to give an amino group or 4
By a method of obtaining an anion exchange resin as a crosslinked polystyrene derivative having a primary ammonium group.

(In the formula, m and n are integers of 0 to 6, and R represents hydrogen or an alkyl group.) Hereinafter, the constituent elements of the present invention will be described in detail.

Examples of the styrene derivative having a glycidyl group represented by the general formula [3] used in the present invention include vinylbenzyl glycidyl ether, methylvinylbenzyl glycidyl ether, vinylphenyl butyl glycidyl ether, vinylbenzyloxyethyl glycidyl ether, and the like. .

As the cross-linking agent, a monomer having two or more vinyl groups capable of copolymerizing with styrene, such as divinylbenzene, divinyltoluene, divinylnaphthalene, ethylene glycol dimethacrylate, and trimethylolpropane tri (meth) acrylate is used.

The copolymerization of the styrene derivative having a glycidyl group and the crosslinking agent can be carried out by a known suspension polymerization. That is, in a water phase containing a dispersion stabilizer, a styrene derivative having a glycidyl group as a monomer phase, a cross-linking agent, a polymerization initiator, and an organic phase containing a porosifying agent are dispersed, and then heated and polymerized. As a result, a bead-shaped copolymer can be obtained. Here, as the dispersion stabilizer, polymer compounds such as gelatin, polyvinyl alcohol, carboxymethyl cellulose, etc., and fine powder inorganic compounds such as magnesium silicate, calcium sulfate, etc. are used at a concentration of 0.05 to 5%. As the polymerization initiator, a peroxide represented by benzoyl peroxide, an azo compound represented by azobisisobutyronitrile, or the like is used in an amount of 0.01 to 10% by weight based on the monomer. In order to obtain a porous crosslinked copolymer, it is necessary to add a porosifying agent to the monomer phase. Examples of the porosifying agent include (cyclo) alkanes such as heptane, octane, decane, and cyclohexane, alcohols such as hexanol, pentanol, and 2-ethylhexanol. Solvents in which a monomer dissolves but a linear polymer does not dissolve (also a poor solvent) 20% to 70% of the monomer, or 40 to 200% of the monomer together with a solvent (also called a good solvent) that also dissolves linear polymers such as toluene and dichloroethane, polystyrene, etc. The linear polymer of 1) may be used alone in an amount of 2 to 40% with respect to the monomer or with a good solvent. The polymerization reaction is carried out mainly by heating at 50 to 90 ° C. for 5 to 24 hours under a nitrogen atmosphere.

The compound used for the amination of the obtained copolymer is ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, aniline, ethylenediamine, diethylenetriamine, As for the primary amine, secondary amine, and tertiary amine that react with glycidyl groups such as polyethyleneimine, all amines can be used regardless of whether they are aliphatic or aromatic.

The solvent for the amination may not be used, but if a solvent that swells the copolymer such as dioxane, ethylene dichloride, or toluene is used, the amination will easily proceed.

The degree of amination can be controlled by controlling the amount of ammonia or amine used. In order to add as many amino groups as possible, 10 to 20 times as much ammonia or amine as the amount of glycidyl groups in the copolymer is used.

The amination reaction is carried out at 20 to 90 ° C for 2 to 24 hours.

The resin that has undergone amination is treated with 1 to 10% sulfuric acid at 50 to 80 ° C for the purpose of eliminating the residual glycidyl group.
The ring-opening reaction is carried out by heating for about 8 hours to obtain an anion exchange resin.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to the following examples unless it exceeds the gist.

Example 1 A: Synthesis of porous cross-linked polyvinyl benzyl glycidyl ether A stirring device, a nitrogen introducing tube, a condenser and a thermometer were attached.
A 500 ml four-necked flask was charged with 275 ml of water containing 2.5 g of polyvinylpyrrolidone as a dispersion medium, and as a monomer phase, 19 g of vinylbenzyl glycidyl ether, 15.4 g of divinylbenzene (purity 55%), 4-methyl-2-pen. 28g Tanol, 7g Octane, Azobisisobutyronitrile
0.7 g of the mixed solution was dispersed. After dispersing for 30 minutes in a nitrogen atmosphere, a polymerization reaction was carried out at 70 ° C for 24 hours. The obtained copolymer beads were washed with excess methanol, hot methanol, and then with acetone, and dried under reduced pressure at 60 ° C. The yield was 31 g.

The epoxy ring content of the obtained copolymer beads was measured by the hydrochloric acid-dioxane method and found to be 2.5 mmol / g.

B: Amination of porous cross-linked polyvinyl benzyl glycidyl ether 5.0 g of the copolymer obtained in A and 50 ml of dioxane were placed in a three-necked flask equipped with a stirrer, a cooler and a thermometer.
The resin was degassed using an aspirator until the air bubbles disappeared. Thereafter, 25.8 g of diethanolamine was added, and an amination reaction was carried out at 80 ° C. for 24 hours while stirring. After completion of the amination, the resin was filtered, washed with dioxane, and further washed with acetone.

After drying under reduced pressure at 60 ° C., the yield was measured and found to be 6.2 g. Further, when the residual glycidyl group was quantified by the hydrochloric acid-dioxane method, it was found to be 5% and the reaction rate was 95%.

Example 2 A: Synthesis of porous cross-linked polyvinyl benzyl glycidyl ether In a four-necked flask equipped with a stirrer, a nitrogen inlet tube, a condenser and a thermometer, 300 ml of water containing 1.5 g of polyvinyl alcohol was placed as a dispersion medium, As a monomer phase, a mixed solution of 20 g of vinylbenzyl glycidyl ether, 20 g of divinylbenzene (purity 56%), 15 g of n-heptane and 0.2 g of 2,2'-azobis-2,4-dimethylvaleronitrile was dispersed. After dispersing for 30 minutes in a nitrogen atmosphere, a polymerization reaction was carried out at 70 ° C. for 8 hours. The obtained copolymer beads are
After washing with water, washing with acetone, and drying under reduced pressure at room temperature. The yield was 32 g.

B: Amination of porous cross-linked polyvinyl benzyl glycidyl ether To a three-necked flask equipped with a stirrer, a condenser and a thermometer, 5.0 g of the copolymer obtained in A, 50 ml of dioxane and 15 g of diethylamine were added, and the mixture was stirred at 80 The reaction was carried out at -8 hours. After completion of the amination reaction, the resin was filtered and washed with dioxane and water. Then, in order to eliminate the remaining epoxy ring, the following ring opening reaction was carried out.

The resin after amination was brought into contact with diluted sulfuric acid to form a sulfate, 50 ml of 10% sulfuric acid was added, and the mixture was heated at 60 ° C. for 5 hours. The resulting resin is washed with water and regenerated with diluted sodium hydroxide,
It was washed thoroughly with water. When the exchange capacity (hydrochloric acid adsorption capacity) of the weakly basic anion exchange resin thus obtained was measured, it was 1.6 meq / g.

Example 3 Amination of Porous Crosslinked Polyvinyl benzyl glycidyl ether; 5.0 g of the copolymer beads obtained in Example 2A were reacted with 40 ml of 30% trimethylamine at 30 ° C for 4 hours and 50 ° C for 4 hours. It was The reaction operation was performed in the same manner as in Example 2B.

The neutral salt decomposing ability of the obtained quaternary ammonium type strongly basic anion exchange resin was measured and found to be 1.3 meq / g.

Example 4 Amination of porous cross-linked polyvinyl benzyl glycidyl ether; 5.0 g of the copolymer beads obtained in Example 2A were reacted with 30 ml of 28% ammonia water at 30 ° C for 4 hours and 60 ° C for 4 hours. Let The reaction operation was performed in the same manner as in Example 2B.

The exchange capacity (hydrochloric acid adsorption capacity) of the obtained weakly basic anion exchange resin was measured and found to be 1.2 meq / g.

Example 5 A: Synthesis of crosslinked polyvinylbenzyl glycidyl ether As a monomer phase, vinylbenzyl glycidyl ether was used.
10g, divinylbenzene (purity 56%) 2.5g, toluene 6.2
g, 2,2'-azobis-2,4-dimethylvaleronitrile 0.1
100 ml of 0.5% polyvinyl alcohol water using a mixed solution of g
Polymerization was carried out in the same manner as in Example 2 · A except that was used.
The obtained copolymer beads were washed with water, washed with water, and washed with acetone, and then contacted with dioxane to replace acetone with dioxane.

B: Amination of cross-linked polyvinyl benzyl glycidyl ether 10 g of dioxane-containing copolymer beads obtained in A,
Reacted with 15 g of diethylamine. The reaction procedure is described in Example 2.
・ Same as B.

The exchange capacity (hydrochloric acid adsorption capacity) of the obtained weakly basic anion exchange resin was measured and found to be 3.2 meq / g.

〔The invention's effect〕

According to the present invention, a chemically stable new anion exchange resin can be easily produced.

Claims (2)

[Claims] 1. A crosslinked copolymer having a styrene unit, wherein an anion exchange resin having a functional group represented by the following general formula [1] or [2] bonded to an aromatic ring of the copolymer. (In the general formula, m and n are integers of 0 to 6, R ₁ , R ₂ and R ₃
Represents hydrogen, an alkyl group, or a hydroxyalkyl group. ) 2. A styrene derivative having a glycidyl group represented by the following general formula [3] is copolymerized with a monomer having two or more vinyl groups, and the glycidyl group of the obtained copolymer is A method for producing an anion exchange resin, which comprises reacting with ammonia or amine. (In the formula, m and n are integers of 0 to 6, and R represents hydrogen or an alkyl group.)