JPH0241528B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a spherical anion exchange resin.

One of the reasons why ion exchange technology using ion exchange resins is widely used is that its purpose is achieved through column processing, which is a simple operation.
In order to make this operation practically possible, it is a necessary condition that the ion exchange resin has a spherical shape.

Regarding the manufacturing method of spherical anion exchange resin,
Although various methods have been proposed, they can be roughly classified into the following four types based on the raw materials for producing the polymer substrate. That is, m-phenylenediamine resin,
Epichlorohydrin resin, (meth)acrylic acid ester, (meth)acrylamide resin,
It is a styrene resin. Further, if classified based on the polymerization reaction type, the first two are condensation systems, and the latter two are addition polymerization systems. The reason why condensation resins are rarely used at present is that the spheroidizing process
The reason for this is that it is less efficient than addition polymerization systems. Also used relatively often (meta)
Acrylic acid esters and (meth)acrylamide-based resins have limited usage conditions because of their hydrolyzability. Styrene and divinylbenzene are made into spherical particles by suspension polymerization in water using a dispersant, then chloromethylated with chloromethyl ether using a Lewis acid catalyst, and further reacted with amine etc. to form an anion exchange resin. The styrenic resin mentioned above has problems in the manufacturing process, such as the toxicity of the chloromethylating agent and the polymer reaction.

As an anion exchange resin other than the above-mentioned resins, for example, in US Pat. No. 2,687,382, tetraallylammonium bromide is prepared in t-
The anion exchange resin was obtained with a yield of 76% by polymerizing with butyl hydroperoxide at 75°C for 20 hours. However, in the examples of this patent, even the example showing the highest yield was at most 83%, requiring a long polymerization time. In addition, the shape is
This is a so-called crushed product, which poses a problem in practical terms.

As a result of extensive research into the method for producing spherical anion exchange resins, the inventors of the present invention found that (1) dialkyl diallylammonium chloride (however, the alkyl group may be substituted with a hydroxyl group), and (2 ) A compound containing at least two or more diallylammonium groups in the same molecule, a compound containing at least two or more para (or meta) vinylphenylmethylammonium groups in the same molecule, or an aqueous solution containing a mixture thereof. , when producing a copolymer by suspending it in a water-insoluble organic solvent, (3) 0.1 to 10% by weight of one or more vinyl monomers having a hydrophilic group, (4 ) obtained by radical polymerization of a mixture with one or more hydrophobic vinyl monomers that are copolymerizable with the vinyl monomer (3) and whose polymer has good solubility in the organic solvent; We have discovered a method for producing a spherical anion exchange resin characterized by using a copolymer that is sufficiently soluble in a solvent as a dispersant.

According to the present invention, a truly spherical anion exchange resin with a small particle size distribution and a high exchange capacity can be produced in high yield.

The main monomers constituting the anion exchange resin produced by the method of the present invention are as follows. Examples of the dialkyldiallylammonium chloride include dimethyldiallylammonium group chloride, diethyldiallylammonium chloride, methyl-β-hydroxyethyldiallylammonium chloride, and the like. Compounds containing at least two diallylammonium groups in the same molecule include N,N'-tetraallylpiperazinium dichloride, N,N'-dimethyl-N,N'-tetraallyl-2-butene-1,
Examples include 4-diammonium dichloride.

Compounds containing at least two para (or meta) vinyl phenylmethyl ammonium groups in the same molecule include N,N'-di(para (or meta)
vinylphenylmethyl)ethylenediammonium dichloride, N,N'-di(para(or meta)
Examples include vinylphenylmethyl)propylene diammonium dichloride.

The amount of monomer (2) used is monomer (1) and monomer (2).
Although it is preferable that the amount is 5 to 60% by weight based on the total weight of the material, there is no particular limitation.

These monomers are polymerized in an aqueous solution, but the concentration is not particularly limited, but is preferably
50-75% by weight.

The dispersant used in the present invention is a copolymer of a vinyl monomer (3) having a hydrophilic group and a hydrophobic vinyl monomer (4).
Examples of (3) include vinyl monomers having carboxyl groups, amide groups, amino groups, sulfonic acid groups, hydroxyl groups, etc., such as (meth)acrylic acid,
Itaconic acid, (meth)acryamide, N-vinylpyrrolidone, (meth)acrylic acid aminoalkyl ester, hydroxyethyl (meth)acrylate, etc. are also used as hydrophobic vinyl monomers (4) that can be copolymerized with vinyl monomer (3). Styrene, (meth)acrylic acid alkyl ester, acrylonitrile, vinyl acetate, etc. can be used, and the selection of these types and amounts differs depending on the type of organic solvent used. Just follow the general rule that it dissolves in These vinyl monomers
Among (4), alkyl esters of (meth)acrylic acid having 1 to 12 carbon atoms are particularly preferred from the viewpoint of ease of adjusting solubility in organic solvents. Vinyl monomer(3)
is copolymerized in an amount of 0.1 to 10% by weight, but preferably,
0.1 to 6% by weight. Further, the degree of polymerization of the dispersant polymer is within a range that maintains good solubility in the organic solvent used, and the higher the degree of polymerization, the better the dispersibility.

The dispersant used in the present invention is one that is sufficiently soluble in an organic solvent, that is, one that has good solubility in an organic solvent. It is preferable to use a material that can be dissolved in the organic solvent used even at a temperature 50° C. lower than the polymerization temperature in water drop type reverse phase suspension polymerization. Particularly preferred dispersants are those that can be dissolved in the organic solvent used even at a temperature 100° C. lower than the polymerization temperature at which the polymerization of the present invention is carried out. (However, if the organic solvent solidifies at a temperature lower than the above-mentioned 50°C or 100°C, it can be dissolved at a temperature above the freezing point.) The dispersant polymer used in the present invention can be synthesized by solution polymerization, Any of the general methods such as emulsion polymerization method and suspension (normal phase) polymerization method can be used, but emulsion polymerization method and suspension polymerization method are particularly suitable because they are easy to obtain a polymer with a high degree of polymerization. Further, as a polymerization initiator used during polymerization, for example, a redox system such as benzoyl peroxide, azobisisobutyronitrile, ammonium persulfate, etc. can be used alone or in combination with a reducing agent.

The amount of the dispersant used in the present invention is preferably 0.001 to 1% by weight, particularly preferably 0.005 to 0.5% by weight, based on the aqueous monomer solution.

As the organic solvent used in the present invention, any solvent can be used as long as it is generally called a hydrophobic solvent, but typical aromatic hydrocarbons include benzene, toluene, and xylene. Examples of aliphatic hydrocarbons include n-hexane, n-heptane, n-octane, and cyclohexane; examples of halogenated hydrocarbons include chlorides; tri- or tetrachloroethylene;
Examples include tri- or tetrachloroethane, carbon tetrachloride, and mono- or dichlorobenzene. These solvents may be used alone or as a mixed solvent of two or more.

When producing the anion exchange resin according to the present invention, any polymerization initiator that generates free radicals at the polymerization temperature can be used. For example, ammonium persulfate group, potassium persulfate, benzoyl peroxide, cumene hydroperoxide, azobisisobutylnitrile, 2,2'-azobis(2-amidinopropane) hydrochloride, 4,4'-azobis-4-
Cyanopentanoic acid etc. can be used, but preferably 2,2'-azobis(2-amidinopropane)
It is hydrochloride.

The polymerization of the present invention can be carried out as follows.

A monomer aqueous solution to which a polymerization initiator has already been added is dispersed with stirring into an organic solvent in which a dispersant polymer is preferably dissolved in 0.001 to 1% by weight, particularly preferably 0.005 to 0.5% by weight (based on the monomer aqueous solution). let Although the ratio of the monomer aqueous solution as the dispersed phase and the organic solvent as the continuous phase is not particularly limited, it is preferable that the dispersion ratio of the aqueous solution is about 60% or less.

The order in which the components are added is not critical and may differ from the order described herein.

The rotation speed for stirring is determined depending on the desired particle size.

Next, the atmosphere in the reaction system is replaced with nitrogen, and the temperature is raised to a predetermined polymerization temperature. This temperature is not particularly limited as long as the solubility of the dispersant polymer used is maintained.

After the polymerization is completed, it is cooled and filtered to obtain a spherical polymer. If necessary, the polymer can be dehydrated by azeotroping with the organic solvent used.

Next, the present invention will be explained by reference examples and examples.

The performance evaluation of the anion exchange resin in the present invention is based on the neutrality of the anion exchange resin, edited by the Society of Polymer Science Editorial Committee for Polymer Experiments, Vol. 7 "Functional Polymers" (published by Kyoritsu Publishing Co., Ltd.), page 25. The salt decomposition capacity measurement method was used.

Reference example 1 (Synthesis of dispersant polymer) 30ml of distilled water in a separable flask with a capacity of 500ml
ml and an aqueous solution consisting of 2.0 g of polyoxyethylene (n=30) octyl phenyl ether, and while replacing the atmosphere with nitrogen gas, the temperature was raised to a polymerization temperature of 40°C. Next, an aqueous solution consisting of 8 g of polyoxyethylene (n=30) octyl phenyl ether, 0.2 g of sodium lauryl sulfate, and 70 g of distilled water, 3 g of acrylic acid (2.9 g in the monomer), and 60 g of 2-ethylhexyl acrylate (58.3 g in the monomer) were added. %), a monomer mixture consisting of 40 parts of styrene (38.8% in monomer)
103g and ammonium persulfate as a polymerization initiator
Add 10% of a monomer pre-emulsion consisting of 0.125g (0.12% of monomer) into the flask,
Then add 10% of an aqueous reducing agent solution consisting of 0.075 g of acidic sodium sulfite and 30 ml of distilled water. After the polymerization begins and the temporary heat generation subsides, the remaining 90% of the monomer pre-emulsion and the reducing agent aqueous solution are simultaneously drop-polymerized over a period of 4 hours.
Thereafter, the temperature of the polymerization system is raised to 90°C, maintained for 1 hour, and then cooled to room temperature. During the polymerization, stirring is continued while constantly flowing a small amount of nitrogen. The resulting polymer emulsion had a solids content of 43%. The dispersant polymer obtained here contains toluene,
For xylene, tetra or trichloroethylene, etc.
It was sufficiently dissolved at 10°C.

Reference example 2 (Synthesis of dispersant polymer) 2 g of dimethylaminoethyl methacrylate (1.9% in monomer), 2-ethylhexyl acrylate
Polymerization was carried out in the same manner as in Reference Example 1 except that 100 g (98.1% in monomer) was used. The obtained dispersant polymer was sufficiently dissolved in n-hexane, n-heptane, n-octane, toluene, xylene, tetra or trichloroethylene, chlorobenzene, etc. at 0°C.

Reference Example 3 (Synthesis of dispersant polymer) 3 g of acrylic acid (2.9% in monomer), 40 g of 2-ethylhexyl acrylate (38.8% in monomer),
Polymerization was carried out in the same manner as in Reference Example 1 except that 60 g of isobutyl methacrylate (58.3% in monomer) was used. The obtained dispersant polymer was sufficiently dissolved in n-heptane/tetrachloroethylene (=6/4 volume ratio) mixture, toluene, xylene, tetra or trichloroethylene, etc. at 0°C.

Reference example 4 (Synthesis of dispersant polymer) 2 g of N-vinylpyrrolidone (1.9% in monomer),
The polymerization method was the same as in Reference Example 1 using 60 g of 2-ethylhexyl acrylate (58.8% in the monomer) and 40 g of isobutyl methacrylate (39.3% in the monomer). The resulting dispersant polymer is toluene, xylene, tetra or trichloroethylene, xylene/
It was dissolved in a tetrachloroethylene (=7/3 volume ratio) mixture at 5°C.

Reference example 5 (Synthesis of dispersant polymer) 2.37 parts of sodium chloride, sodium polyacrylate
An aqueous solution consisting of 0.052g (0.05% of monomer) and 235g of distilled water is placed in a 500ml separable flask with two baffles, and the temperature is raised to 60°C while replacing the atmosphere with nitrogen gas. Next, the rotation speed of the stirring blade was set to 350 to 400 rpm, and 3 g of dimethylaminoethyl methacrylate (2.9% in monomer) and styrene were added.
A solution of 0.258 g of azobisisobutyronitrile (0.25% of the monomer) as a polymerization initiator is added to 103 g of a monomer mixture consisting of 60 g (58.3% of the monomer) and 40 parts of isobutyl methacrylate (38.8% of the monomer). . Approximately 1 hour after adding the monomer, the temperature inside the flask reaches a maximum of 62-63°C. Thereafter, the mixture was reacted for 4 hours, cooled to room temperature, filtered and dried. The obtained polymer particles (dispersant) have a particle size of 0.2 to
1.0mm spherical particles, toluene, xylene,
Tetra or trichloroethylene, chlorobenzene, n-heptane/tetrachlorethylene (=
6/4 volume ratio) mixture etc. at 5°C.

Example 1 (Manufacture of anion exchange resin) In a 500 ml round bottom separable flask equipped with two baffles, 180 ml of toluene, 54 g of dimethyldiallylammonium chloride, and N,N'-dimethyl-N,N'- tetraallyl-2-butene-1,
24g of 4-diammonium dichloride, 2,2'-
Azobis(2-amidinopropane) hydrochloride 0.39g
120g of an aqueous solution containing PH6.0 was charged. Set the rotation speed of the stirring blade to 180 rpm, and add 0.56 g of the polymer emulsion synthesized in Reference Example 1. Next, the atmosphere is replaced with nitrogen gas. After about 30 minutes, a homogeneous dispersion will occur. Raise the bath temperature to 50℃. After 2 hours, the temperature is raised to 60°C, and after another 2 hours, the temperature is raised to 70°C. After further carrying out a polymerization reaction at 80°C for 2 hours, the mixture was cooled and filtered to obtain a spherical polymer. acetone
After washing with 300 ml, it was thoroughly washed with water. Yield is 91
%, and the average particle size was 0.35 mm. The neutral salt decomposition capacity of the obtained anion exchange resin was 5.1 meq/g.

Example 2 (Production of anion exchange resin) In a 500 ml round bottom separable flask equipped with two baffles, 195 ml of n-heptane, 50 g of diethyl diallylammonium chloride, N,N'-
Di(para(meth)vinylphenylmethyl)ethylenediammonium dichloride 12g (40% para,
mixture of 60% meta-isomer), 2,2'-azobis (2-
105 g of an aqueous solution containing 0.33 g of (amidinopropane) hydrochloride and having a pH of 6.5 was charged. The rotation speed of the stirring blade
Set the speed to 250 rpm, and add 1.0 g of the polymer emulsion synthesized in Reference Example 2. Next, the atmosphere is replaced with nitrogen gas. After about 30 minutes, a homogeneous dispersion will occur.
Raise the bath temperature to 45℃. After 2 hours, the temperature was raised to 55℃,
After another 2 hours, the temperature is raised to 70°C. After further carrying out a polymerization reaction at 80°C for 2 hours, the mixture was cooled and filtered to obtain a spherical polymer. After washing with 300 ml of acetone, it was thoroughly washed with water. The yield was 95% and the average particle size was 0.23 mm. The neutral salt decomposition capacity of the obtained anion exchange resin was 4.3 meq/g.

Example 3 (Production of anion exchange resin) 200 ml of xylene and methyl-β-hydroxyethyldiallylammonium chloride were placed in a 500 ml round-bottom separable flask equipped with two baffles.
60g, N,N'-di(para(meth)vinylphenylmethyl)propylene diammonium dichloride
10g (mixture of 40% para and 60% meta), 2,
2'-azobis(2-amidinopropane) hydrochloride
100 g of an aqueous solution containing 0.50 g and pH 6.0 was charged. Set the rotation speed of the stirring blade to 170 rpm, and add 0.23 g of the polymer emulsion synthesized in Reference Example 3. Next, the atmosphere is replaced with nitrogen gas. After about 30 minutes, a homogeneous dispersion will occur. Raise the bath temperature to 45℃. After 2 hours, the temperature was raised to 55°C, and after another 2 hours, the temperature was raised to 70°C.
After further carrying out a polymerization reaction at 80°C for 2 hours, the mixture was cooled and filtered to obtain a spherical polymer. acetone 300
ml and then thoroughly washed with water. Yield is 90%,
The average particle size was 0.36 mm. The neutral salt decomposition capacity of the obtained anion exchange resin was 4.5 meq/g.

Example 4 (Production of anion exchange resin) In a 500 ml round bottom separable flask equipped with two baffles, 210 ml of xylene/tetrachloroethylene (=7/3 volume ratio) mixture, 32 g of dimethyldiallylammonium chloride, and N , N'-tetraallylpiperazinium chloride 22g, 2,
2'-azobis(2-amidinopropane) hydrochloride
90 g of an aqueous solution containing 0.45 g and pH 6.5 was charged. Set the rotation speed of the stirring blade to 150 rpm, and add 0.84 g of the polymer emulsion synthesized in Reference Example 4.
Next, the atmosphere is replaced with nitrogen gas. After about 30 minutes, a homogeneous dispersion will occur. Raise the bath temperature to 50℃. After 2 hours, the temperature is raised to 60°C, and after another 2 hours, the temperature is raised to 70°C. After further carrying out a polymerization reaction at 80°C for 2 hours, the mixture was cooled and filtered to obtain a spherical polymer. acetone
After washing with 300 ml, it was thoroughly washed with water. Yield is 90
%, and the average particle size was 0.40 mm. The neutral salt decomposition capacity of the obtained anion exchange resin was 4.8 meq/g.

Example 5 (Production of anion exchange resin) 180 ml of n-heptane/tetrachloroethylene (=6/4 volume ratio) mixture was placed in a 500 ml round-bottom separable flask equipped with two baffles, Reference Example 5
0.12g of polymer particles synthesized in 1. After confirming that the polymer particles were dissolved, 39 g of diethyldiallylammonium chloride, N,N'-dimethyl-N,N'-tetraallyl-2-butene-1,
4-diammonium dichloride 39g, 2,2'-
Azobis(2-amidinopropane) hydrochloride 0.39g
120g of an aqueous solution containing PH6.5 was charged into a flask.
Set the rotation speed of the stirring blade to 140 rpm, and replace the atmosphere with nitrogen gas. After about 20 minutes, a homogeneous dispersion will occur. Raise the bath temperature to 50℃. After 2 hours, the temperature is raised to 60°C, and after another 2 hours, the temperature is raised to 70°C. After further carrying out a polymerization reaction at 80°C for 2 hours, the mixture was cooled and filtered to obtain a spherical polymer. After washing with 300 ml of acetone, it was thoroughly washed with water. Yield is 93%, average particle size is
It was 0.43mm. The neutral salt decomposition capacity of the obtained anion exchange resin was 4.0 meq/g.

Claims (1)

[Scope of Claims] 1. A dialkyl diallylammonium chloride (however, the alkyl group may be substituted with a hydroxyl group); 2. A compound containing at least two or more diallylammonium groups in the same molecule; When producing a copolymer by suspending an aqueous solution containing a compound containing at least two meta)vinylphenylmethylammonium groups in the same molecule, or a mixture thereof, in a water-insoluble organic solvent. 3. 0.1 to 10% by weight of one or more vinyl monomers having a hydrophilic group; 4. A hydrophobic polymer that can be copolymerized with the vinyl monomer 3 and that has good solubility in the organic solvent. A spherical anion exchange resin characterized in that a copolymer obtained by radical polymerization of a mixture with one or more vinyl monomers and which is sufficiently soluble in the organic solvent is used as a dispersant. Manufacturing method.