JPH0242369B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for producing a granular basic ion exchange resin.

According to the method of the present invention, by not using aliphatic tertiary amines to form anion exchange groups, environmental hygiene during resin production is significantly improved, and the resulting resin has excellent heat resistance and ion exchange properties. become capable.

The granular basic ion exchange resin obtained by the present invention can be used for water treatment, purification of various chemical solutions, separation of amino acids, nucleic acids, etc., polymer catalysts, etc.

Improvements of the invention in relation to the prior art Conventionally, typical strong basic exchange resins contain quaternary ammonium salts as ion exchange groups. This quaternary ammonium salt reacts an aliphatic tertiary amine (especially trimethylamine) with a haloalkyl group (especially a chloromethyl group) introduced on a crosslinked polymer (addition polymer, polyaddition polymer, or polycondensation polymer). It is formed by

However, such conventional methods for producing strongly basic exchange resins have several drawbacks.

First, conventional methods generally require complicated manufacturing steps. That is, the most typical strong basic exchange resin is produced by chloromethylating a crosslinked polymer (for example, polystyrene crosslinked with divinylbenzene) with chloromethyl methyl ether and converting it into a quaternary ammonium salt. Chloromethylation must be carried out in the presence of a suitable solvent and catalyst, and is a complicated process in itself and in the necessity of removing the solvent and catalyst after the reaction. Furthermore, trimethylamine is generally used for quaternary ammonium saltation, but this amine is a foul-smelling substance and its use is unfavorable in view of the working environment.

Another drawback of this kind of process using aliphatic tertiary amines, especially trimethylamine, for the formation of anion exchange groups is that the product strongly basic exchange resin has a low heat resistance. In the current situation where strongly basic exchange resins are required to be used at high temperatures as their applications expand, poor heat resistance brings about various restrictions on their applications.

In order to solve these drawbacks, the present inventors invented a method for producing anion exchange resins that uses imidazole to form anion exchange groups (Japanese Patent Application Laid-Open No.
51―151681). The production method of the invention is a method in which a halomethyloxirane compound is reacted with an imidazole, and the obtained modified imidazole (intermediate) is reacted with a polyfunctional epoxy compound to obtain an anion exchange resin.

Although the invention is a method to overcome the conventional drawbacks,
It has the following drawbacks.

That is, since the above-mentioned modified imidazoles are mixtures of imidazole, 1:1 adducts, 1:2 adducts, and oligomers of imidazole and halomethyloxirane compounds, the obtained anion exchange resin is based on imidazoles. Among the basic exchange groups, the content of imidazolium bases that contribute to neutral salt decomposition ability is small, and the activity as a strong basic exchange resin is low.

Summary of the Invention The present invention relates to a general formula obtained by reacting a halomethyloxirane compound and an imidazole, (However, R ¹ is a hydrogen atom, an alkyl group with 1 to 17 carbon atoms, or an aryl group with 6 to 8 carbon atoms, R ² is a hydrogen atom or an alkyl group with 1 to 3 carbon atoms, X is a halogen atom, A particulate basic ion characterized by suspending a polymeric quaternary salt (n is an integer of 1 or more) and a polyfunctional epoxy compound in an oily medium and then heating the suspension to cause a curing reaction. A method for producing a replacement resin is provided.

Detailed Description of the Invention The polymeric quaternary salt used in the method of the present invention has the general formula [] obtained by reacting a halomethyloxirane compound and an imidazole, (However, R ¹ is a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, or an aryl group having 6 to 8 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X is a halogen group, n represents an integer of 1 or more).

Here, the halomethyloxirane compound has the following general formula [], (wherein X is a halogen atom, especially chlorine, bromine or iodine). Specific examples include epichlorohydrin, epibromohydrin, and the like. These can be used together.

In addition, imidazoles have the following general formula [], (However, R ¹ is a hydrogen atom, an alkyl group having 1 to 17 carbon atoms such as methyl, ethyl, propyl, hexyl, undecyl, heptadecyl; phenyl, tolyl,
It is a compound represented by an aryl group having 6 to 8 carbon atoms such as xylyl; ^R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms such as methyl, ethyl, n-propyl, etc.). Specific examples of imidazoles include the following. imidazole,
2-Methylimidazole, 2-ethylimidazole, 2-propylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-
Heptadecylimidazole, 2-ethyl-4-methylimidazole, 2,4-dimethylimidazole, 2-phenyl-4-methylimidazole, etc.
These can be used together.

The polymer quaternary salt is prepared by reacting a halomethyloxirane compound represented by the above general formula [] with an imidazole represented by the above general formula [].

This reaction solvent may be any solvent as long as it is inert to the reaction components and does not interfere with resin formation by the polyfunctional epoxy compound described later, but it is suitable for preparing quaternary salts with large molecular weight polymers. Water is particularly preferred.

As for the reaction molar ratio, 0.9 to 1.5 mol of halomethyloxirane compound is used per 1 mol of imidazole, and 1 to 1.1 mol is particularly preferable.

The reaction temperature used is 30 to 150℃, but especially
50-120°C is preferred. If it is less than 30°C, the reaction rate is slow, and if it exceeds 120°C, side reactions are likely to occur, which is not preferable.

In addition, a halomethyloxirane compound was added dropwise to imidazoles at a temperature of 50 to 80°C, and after the completion of dropping,
Preferably, the temperature is raised to ~120°C.

A suitable reaction time is 2 to 30 hours.

The polyfunctional epoxy compound used in the method of the present invention is a compound having two or more oxirane rings.

A group of polyfunctional epoxy compounds suitable for use in the present invention are those known as so-called epoxy resins having an epoxy equivalent weight of about 100 to 3000. Specifically, bisphenol-based epoxy resins (e.g., bisphenol A diglycidyl ether), polyglycol-based epoxy resins (e.g., ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether), alicyclic epoxy resins (e.g. vinyl cyclohexene diepoxide), carboxylic acid epoxy resins (e.g. diglycidyl phthalate),
Amine-based epoxy resins [for example, glycidylaniline, tetraglycidyl compounds of 4,4'-methylene dianiline, the following general formula [], (However, R ¹ and R ² are the same as the general formula [], n is 0
or an integer)], novolak-based epoxy resins (for example, phenol novolac glycidyl ether), and two or more of these can also be used in combination.

The diglycidyl compound having an imidazolium base represented by the general formula [] is synthesized by reacting a predetermined amount of a halomethyloxirane compound with the polymeric quaternary salt represented by the general formula [] prepared as described above. This can be done by carrying out alkali treatment after treatment.

That is, the reaction is summarized as follows.

Also, represented by n=0 in the general formula [], can be easily synthesized by reacting an imidazole and a halomethyloxirane compound at a molar ratio of 1:2, followed by alkali treatment.

The oil-based medium used in the method of the present invention is used as a heating medium to maintain the mixed solution of the polymer quaternary salt preparation and the polyfunctional epoxy compound in a suspended state and to provide a temperature for curing. Anything that works can be used.

One example of an oily medium is an animal or vegetable oil, especially a vegetable oil. Specifically, semi-drying oils or non-drying oils such as sesame oil, edible oil, rapeseed oil, olive oil, and peanut oil are suitable.

Another example of an oily medium is paraffin. Those that are liquid at the heating curing temperature (this condition also applies to the above-mentioned animal and vegetable oils) are used.

In the present invention, the polymer quaternary salt and the polyfunctional epoxy compound are usually mixed and then suspended in the oily medium.

In addition, when using a diglycidyl compound having an imidazolium base represented by the general formula () as a polyfunctional epoxy compound, a portion of the polymer quaternary salt prepared as described above that can react with a portion of the diglycidyl compound may be used. By reacting a fixed amount of a halomethyloxirane compound and then treating it with an alkali, the above-mentioned diglycidyl compound can be synthesized and mixed with the polymeric quaternary salt at the same time, so this is a method of suspending it in the above-mentioned oily medium. is also possible.

The diameter of the suspended particles is generally 0.1 to 1.0 mm, preferably 0.3 to 0.8 mm.

Although a suspension having such a particle size can be obtained simply by stirring the system, it is preferable to use a suspension stabilizer to make the suspension smooth. A suspension stabilizer is dissolved in an oily medium, and a polymer quaternary salt,
Usually, a mixture of polyfunctional epoxy compounds is dispersed and suspended.

Suspension stabilizers for smoothing the suspension state of the suspension used in the method of the present invention generally include:
Any known suspension stabilizer substance capable of dispersing and suspending a hydrophilic substance in an oily medium can be used, but typical examples include surfactants, especially HLB (hydrophilic-lipophilic balance) is a nonionic surfactant or anionic surfactant with 12 or less.

The polyfunctional epoxy compound used in the method of the present invention may contain 5 to 70% of the total amount of the polymeric quaternary salt.
% by weight, preferably from 15 to 60% by weight.

The amount of suspension stabilizer used if necessary is, for example, in the case of a surfactant (especially a nonionic surfactant), 1 to 1% of the total amount of the polymeric quaternary salt and the polyfunctional epoxy compound. ~40% by weight, especially 3-20% by weight is usual.

The amount of oily medium can be any amount that does not cause the suspended particles to coalesce from overcrowding before hardening into beads. Generally, an amount of 1 to 10 times the weight of the suspended particles to be cured is used.

Next, as described above, the suspension of the polymeric quaternary salt and the polyfunctional epoxy compound in an oily medium is heated to cause a curing reaction between the polymeric quaternary salt and the polyfunctional epoxy compound.

Heating is carried out at 60-150°C, preferably 80-110°C.

Heating time is about 2 to 15 hours.

After curing, the beaded resin is separated, deoiled, and washed with water to obtain the desired granular strongly basic ion exchange resin.

Effects of the Invention The basic ion exchange resin obtained by the method of the present invention has superior ion exchange ability compared to the known anion exchange resin disclosed in JP-A-52-151681, and The resin is less colored, less produces low molecular weight substances, and has excellent heat resistance.

By the method of the present invention, it has become possible to provide basic ion exchange resin granules having the above-mentioned excellent characteristics in a simple manner.

Experimental Examples Example 1 In a four-necked flask equipped with a reflux condenser, a thermometer, and a stirrer, 72.4 g of 2-methylimidazole (0.88
mol) and add 100ml of water to make a homogeneous solution.
While keeping the reaction temperature at 50 to 55°C, 81.6 g (0.88 mol) of epichlorohydrin was added dropwise over about 1 hour while stirring, and after further reacting at this temperature for 4 hours, the reaction temperature was raised to 90°C. By continuing stirring for 14 hours, a prepared solution of a polymeric quaternary salt (referred to as Intermediate A) is obtained.

After uniformly mixing 25 g of this intermediate A with 8.3 g of the bifunctional epoxy compound "Epolite 40E" (manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.), Newcol20”HLB=8.1) Sesame oil 200 containing 4g
Gradually add to g while stirring.

Heat at 80°C for 3 hours to perform bead-like condensation and harden.

After cooling, the bead-shaped cured product is separated, deoiled, and then washed with water to obtain the desired strong basic ion exchange resin.

The obtained strongly basic ion exchange resin was colorless and odorless, and was a bead-shaped resin (particle size: 0.3 to 0.7 mm) with a neutral salt decomposition ability of 4.1 meq/g (dry material).

Example 2 25g of intermediate A obtained in Example 1 and compound [M] which is a bifunctional epoxy compound, After homogeneously mixing 6.3 g of the mixture, heating and post-treatment were performed in the same manner as in Example 1.

The obtained strongly basic ion exchange resin was colorless and odorless, and was a bead-shaped resin (particle size: 0.3 to 0.7 mm) with a neutral salt decomposition ability of 4.9 meq/g (dry material).

The bifunctional epoxy compound [M] was synthesized as follows.

24.6 g (0.3
mol) and add 60ml of water to make a homogeneous solution.
While maintaining the reaction temperature at 25 to 30°C, 55.5 g (0.6 mol) of epichlorohydrin was added dropwise over 1 hour while stirring, and the mixture was allowed to react for 3 hours.

Then, the reaction solution was cooled and kept at 0 to 5°C, and 20%
By dropping 60 ml (0.3 mol) of sodium hydroxide aqueous solution over 1 hour and continuing stirring for 3 hours,
A prepared solution of bifunctional epoxy compound [M] was obtained.

Example 3 15g of intermediate A obtained in Example 1 and compound [N] which is a bifunctional epoxy compound, After homogeneously mixing 15 g of the sample, heating and post-treatment were performed in the same manner as in Example 1.

The obtained strongly basic ion exchange resin was colorless and odorless, and was a bead-shaped resin (particle size: 0.3 to 0.7 mm) with a neutral salt decomposition ability of 5.1 meq/g (dry material).

In addition, the synthesis of the bifunctional epoxy compound [N] was performed by keeping the prepared solution of the polymer quaternary salt (intermediate A) obtained in Example 1 at 50 to 55°C and adding 9.3 g (0.1 g of epichlorohydrin) with stirring. mol) was added dropwise over 1 hour, and the mixture was allowed to react for 3 hours.

Next, the reaction solution was cooled, kept at 0-5°C, and kept at 20°C.
% sodium hydroxide aqueous solution (20 ml (0.1 mol))
After the dropwise addition for 3 hours, stirring was continued for 3 hours to obtain a prepared solution of bifunctional epoxy compound [N].

Reference Example In order to investigate the heat resistance of the resin of the present invention, the resin of the present invention (resin obtained in Example 1 and Example 3) and a commercially available strongly basic ion exchange resin (Diaion PA316 manufactured by Mitsubishi Chemical Corporation: styrene-divinylbenzene) type, crosslinking degree 8%, trimethylammonium salt type, Cl type)
The thermal loss was measured using a differential thermal balance device (manufactured by Rigaku Denki, constant temperature differential thermal balance model 8002H) under the following conditions.

Atmosphere: In air Temperature increase rate: 10°C/min As a result, the resin of the present invention showed no weight loss at all up to 260°C. On the other hand, the heat loss of commercially available products is
It was 13% at 200°C and 25% at 260°C.

Claims (1)

[Claims] 1. A general formula obtained by reacting a halomethyloxirane compound and an imidazole, (However, R ¹ is a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, or an aryl group having 6 to 8 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X is a halogen atom, (n represents an integer of 1 or more) and a polyfunctional epoxy compound are suspended in an oily medium and then heated to cause a curing reaction. Method of manufacturing replacement resin.