JPH0580923B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a latex type (pericular type) anion exchange resin in which an ion exchange latex is chemically retained on the surface of a base material.

<Conventional technology> Ion exchange resins used in high performance liquid chromatographs (e.g. ion chromatographs) have a considerably smaller ion exchange capacity than general ion exchange resins (1/10 of general ion exchange resins). ~1/
Approximately 500) have been made. The manufacturing method of such an ion exchange resin having a low ion exchange capacity is very different from that of general ion exchange resins, and is a special manufacturing method, and the manufacturing method is broadly classified into two types. In other words, the first manufacturing method creates a resin with a low ion exchange capacity by retaining extremely small ion exchange latex on the surface of the base resin (this resin itself is often a chromatographic filler). This is a so-called latex type ion exchange resin manufacturing method, and the second manufacturing method is a so-called chemical bonding type in which ion exchange groups are directly chemically introduced into the surface functional groups of the base resin to create a resin with a low ion exchange capacity. This is a method for producing an ion exchange resin. On the other hand, latex type ion exchange resins are most commonly used in ion chromatographs, especially suppressed ion chromatographs, while bonded ion exchange resins are mainly used in non-suppressed ion chromatographs, and suppressed ion chromatographs. There are almost no commercially available graphs. Latex-type ion exchange resins are based on polystyrene gel or sulfonated polystyrene gel, and the anion exchange latex with a particle size of about 0.01 to 0.1 μm is physically held on the surface using electrostatic adsorption or a glue called a binder. It is something that This type of ion-exchange resin has ion-exchange groups present in high density only on the surface of the resin, so it has the advantage of very rapid separation equilibrium and high separation performance.

However, since latex-type ion-exchange resins are not fillers in which the latex and base material, which have ion-exchange groups, are strictly integrated, the ion-exchange latex may desorb depending on the conditions of use, reducing the separation ability. The disadvantage is that the probability is high. That is, for example, with an electrostatic adsorption type, there is a risk of desorption due to a sudden change in the ionic strength in the mobile phase or sample, and with a physical adsorption type, there is a risk of desorption due to contamination with an organic solvent or mechanical load. It is.

<Problems to be solved by the invention> However, chemically bonded fillers (ion exchange resins)
Although it has various features that latex-type fillers (ion-exchange resins) do not have, and is comparable in performance to latex-type fillers, it is not necessarily superior to latex-type fillers in terms of separation performance and separation characteristics. There is no substitute for the drug. For example, regarding the stability of ion exchange groups, ion exchange resins, which are made of polystyrene and are used in general latex type fillers, are superior to hydrophilic chemically bonded fillers. In addition, since any latex-type filler can be used as long as it does not adversely affect separation, it is easy to improve it to a hard and high-pressure-resistant filler to increase speed. In the case of fillers, it is generally difficult to improve them into hard, high pressure-resistant fillers without significantly changing their separation properties. Because latex-type fillers have these advantages, it is thought that latex-type fillers will continue to be mainstream in the future, but for this reason, it is necessary to create a filler that does not release latex. There is a strong desire for a method for producing anion exchange resins.

The present invention has been made in view of this situation, and its purpose is to provide a method for producing a latex-type anion exchange resin that does not cause desorption of ion exchange latex and is suitable for use in ion chromatographs and the like. There is a particular thing.

<Specific Means for Solving the Problems> The feature of the present invention for solving the above-mentioned problems is that it is a crosslinkable polymer gel that has sulfone groups on its surface and also has halogen groups, hydroxyl groups, or a base material made of a resin having an epoxy group; an anion exchange latex electrostatically bonded to the base material;
An anion exchange resin comprising a latex-immobilized polymer layer chemically bonded to the surface of the base material and used in high performance liquid chromatography, etc. is manufactured by the following steps (a) to (e). be.

(a) A process of preparing a polymer gel with sulfone groups, hydroxyl groups, halogen groups, or epoxy groups depending on the reaction method.

(b) A step of dispersing the polymer gel in a small amount of an organic solvent, and then dispersing the ion exchange latex in the organic solvent.

(c) Gradually adding the suspension of the ion exchange latex to the slurry of the polymer gel and stirring;
A step of mixing a polyfunctional epoxy compound that will become a fixed polymer layer into the slurry.

(d) A step in which a reaction initiation catalyst is added and the reaction is carried out at a constant temperature for a certain period of time.

(e) A process of washing with an organic solvent, then washing thoroughly with water, and then exchanging with the desired counterion.

<Example> Hereinafter, the present invention will be explained in detail using figures. FIG. 1 is a process diagram illustrating a method for producing an anion exchange resin according to the present invention. In this figure, first, a polymer gel having a sulfone group and a hydroxyl group, a halogen group, or an epoxy group is prepared according to the reaction method (if the resin does not have a sulfone group, it is sulfonated in advance). Next, the polymer gel (resin) is dispersed in a small amount of organic solvent. Thereafter, the ion exchange latex having hydroxyl groups or epoxy groups is dispersed in an organic solvent. Next, the ion exchange latex suspension is gradually added to the polymer gel (resin) slurry and stirred. Thereafter, a polyfunctional epoxy compound that will become a fixed polymer layer is mixed into the slurry.
Finally, a reaction initiation catalyst is added and the mixture is allowed to react at a constant temperature for a certain period of time. The resin thus obtained is washed with an organic solvent, thoroughly washed with water, and then exchanged with the desired counterion. The ion exchange resin thus obtained is packed into a suitable chromatography tube and used as a separation column to perform ion exchange chromatography.

The above-mentioned manufacturing method will be explained in more detail with reference to a specific example as follows. First, 2.5 g (dry weight) of a hydroxyalkyl methacrylate crosslinked polymer gel (particle size 12 μm) is dispersed in 20 ml of 1N sodium hydroxide. Add 2 g of epichlorohydrin to this gel slurry, and react with stirring in a constant temperature bath at 40° C. for 2 hours to introduce epoxy groups. This epoxidized resin contains 450 μmol/g.
epoxy groups have been introduced. The epoxidized resin is dispersed in 1M sodium sulfite and stirred in a constant temperature bath at 80°C for 5 hours to perform sulfonation. The ion exchange capacity of this resin is approximately 200 μeq/g. This resin is used as a base resin.

10ml of the above base resin (dry weight approx. 2.5g)
Disperse in 4-dioxane and stir with a stirrer. This gel slurry is a quaternary ammonium type anion exchange latex (ion exchange capacity is 1.5 meq/g) in which dimethylethanolamine is introduced into polyglycidyl methacrylate with a particle size of 0.05 μm.
10 ml of methanol suspension (latex concentration 2%)
Add. Next, 1.5 g of diglycerin polyglycidyl ether, which will become the latex fixed polymer layer, was added, and reaction was carried out for 5 hours in a shaker at 45° C. using boron trifluoride diethyl ether complex as a catalyst. After the reaction, the resin was washed with 50 ml of dioxane, then with 100 ml of methanol, and then with 100 ml of pure water. Then dispersed in 0.5N sulfuric acid,
Ultrasound was applied for 15 minutes and then passed through. Furthermore, after washing with 50 ml of 0.5N sulfuric acid, the filtrate was washed with pure water until it became neutral, dispersed in 100 ml of pure water, and decanted 6 times at a rotation speed of 1000 rpm using a centrifuge. I went to Shion. Thereafter, it was dispersed in 0.1N sodium chloride and left overnight. The anion exchange resin thus obtained had an ion exchange capacity of 25 μEq/g.

Incidentally, the structure of the ion exchange resin (filler) produced as described above is as shown in FIG. In FIG. 2, 1 is a base material made of, for example, a cation exchange resin having a reactive group, 2 is an anion exchange latex, which is made of, for example, an anion exchange group or the anion exchange resin itself and has a reactive group;
Reference numeral 3 denotes a latex-fixed polymer layer which is bonded to the base material 1 and the anion exchange latex 2 through, for example, ether bonds. As shown in FIG. 2, the ion exchange resin produced by the production method of the present invention has a base material 1,
It is composed of an ion exchange latex 2 and a latex fixed polymer layer 3, and the latex fixed polymer layer 3 is adapted to cover a resin (substrate) 1 holding an anion exchange latex 2. Also,
The base material 1 is a crosslinkable polymer gel and must have the following functional groups on its surface or be capable of introducing such functional groups. That is, the resin must have a halogen group, a hydroxyl group, or an epoxy group, such as sulfoalkylated polyhydroxyalkyl methacrylate, sulfoalkylated polyvinyl alcohol, sulfoalkylated polyglycidyl methacrylate, and sulfoalkylated polyglycidyl. It is necessary that the resin has ether, sulfoalkylated polymethylolstyrene, or sulfoalkylated polychloromethylstyrene or can be introduced with such a functional group. Furthermore, the ion exchange latex 2 has a particle size of
It is a strong anion exchange resin with a diameter of 0.01 to 0.1 μm, and its base material may be polystyrene-based or polymethacrylate-based. However, the latex base material must have a hydrophilic group (hydroxyl group or epoxy group). When an ion exchange resin with good alkali resistance is required, polystyrene-based resins are preferred, and when more hydrophilicity is required, methacrylate-based resins are preferred.
Further, the shape of the anion exchange latex 2 is not necessarily spherical, and may be a crushed type. Also,
The latex fixed polymer layer 3 includes hydroxyl groups of the base material 1,
It is a substance that reacts with halogen groups or epoxy groups and also reacts with the surface functional groups of the anion exchange latex 2, and is made of a monomer that can coat the surface of the substrate 1 while crosslinking on the surface of the substrate 1.
When the actual substance is a hydroxyl group or an epoxy group, a polyfunctional epoxy compound such as glycerin polyglycidyl ether is preferable. Further, oligomers of epoxy compounds may be used as long as they are substances having a relatively large amount of residual epoxy groups. In addition, if the remaining functional group in the base material 1 is a halogen group, a compound (for example, a polyol compound) that reacts with the halogen group and also reacts with the above-mentioned polyfunctional epoxy compound and a polyfunctional epoxy compound may be used. A polymer layer can be created by mixing and reacting epoxy compounds.

On the other hand, the latex fixed polymer layer 3 is made by polymerizing the monomers added during the above-mentioned manufacturing process, but since this monomer also reacts with the surface functional groups (hydroxyl groups, halogen groups, epoxy groups) in the base material, The latex-fixed polymer layer 3 formed by the reaction is also chemically bonded and fixed to the base material 1. Furthermore, since this monomer is a polyfunctional monomer, the latex-fixed polymer layer formed by polymerization is a crosslinkable polymer layer. Therefore, this polymer layer 3
will not peel off from the base material 1. The anion exchange latex 2 is fixed to the base material (resin) 1 by coating with the latex fixing polymer layer 3.
The monomer for forming the latex-fixed polymer layer 3 reacts with the surface functional groups of the anion exchange latex, and also penetrates into the micropores and polymerizes.
It is more firmly fixed than a simple covering. Since the ion exchange resin of the present invention has the above-described structure and retains the anion exchange latex 2, the anion exchange latex will not be desorbed by organic solvents or high ion concentration solutions. Furthermore, since the base material 1, anion exchange latex 2, and latex-immobilized polymer layer 3 are chemically bonded together, the anion exchange latex 2 is hardly detached even under mechanical load. Furthermore, a latex fixed polymer layer 3
is a three-dimensional crosslinkable polymer and covers the base material 1 with a strong shell, which has the secondary effect of reducing the degree of swelling and contraction of the base material 1 and improving pressure resistance. In addition, the base material 1 and the anion exchange latex (ion exchange group or resin itself) 2 have hydrophilic groups, and the latex fixed polymer layer 3 is also hydrophilic, making it a hydrophilic resin suitable for separating hydrophobic samples. becomes.

The anion exchange resin produced as described above was packed into a stainless steel column with an inner diameter of 4.6 mm and a length of 100 mm, and suppressed ion chromatography was performed using an alkaline mobile phase. The analysis conditions at this time were that the mobile phase was 1.5mM Na2CO3 (PH10.6), 2.0mM Na2CO3 (PH10.6),
ml/min, the measurement temperature is 45℃, the detector is a conductivity detector, the sample concentration is Cl ^- 10ppm,
NO ^- ₃ 20ppm, PO ₄ ^2- 20ppm, SO ₄ ^2- 20ppm, and the sample injection amount was 50μ. In the chromatogram obtained under such analysis conditions, the analyte contained in the injected sample was separated in a short time with a good peak shape, indicating that the anion exchange resin obtained by the production method of the present invention Ion chromatography could be performed satisfactorily. In addition, the base material itself used in the above example (resin before reaction)
When packed into a column with the same column size as in this example (inner diameter 4.6 mm, length 100 mm), the packing flow rate was 3.8 ml/min, but the resin after reaction was 4.5 ml/min.
Filling was possible at ml/min. This means that the flow resistance (pressure resistance) of the base material is improved by using the manufacturing method of the present invention. Although this is different from the purpose of the present invention, it can be said that this is a side effect obtained by the present invention.

Furthermore, in order to investigate the stability of the resin of the present invention against desorption of the anion exchange latex, tests were conducted by extracting the packing material from the column of the above example and dispersing it in various solutions. That is, first, in order to examine the stability against organic solvents, the extracted resin was dispersed in isopropyl alcohol and heated at 50°C.
The mixture was shaken in a constant temperature bath for 8 hours. Thereafter, the resin was washed with pure water, packed into the same stainless steel column as in the previous example, and subjected to ion chromatography. As a result, there was no change in the retention time of each ion. This indicates that no desorption of the anion exchange latex occurred in the organic solvent. Next, similar tests were conducted by dispersing the same resin in 1M sodium chloride and 1N hydrochloric acid, but no shortening of the retention time was observed in either case, indicating that the anion exchange latex was stable and the base resin It was found that it was held in Based on these experimental results,
It can be seen that the resin of the present invention is more stable than a simple glue type. In addition, we have actually investigated the stability of conventional latex-type fillers, but when using fillers retained with a binder, the retention time was reduced to about 1/3 when dispersed in 50% isopropyl alcohol. do. In addition, shortening of the retention time is observed by simply stirring with a stirrer or shaking for a long time. There is not much knowledge about electrostatic adsorption types, but when treated with a solution with high ionic strength, a reduction in retention time is observed, although not as much as when a pasted type is treated with an organic solvent. It is also said that its stability in organic solvents is not very good.

<Effects of the Invention> According to the embodiments of the present invention as described in detail above, the surface of the base material 1 holding the anion exchange latex 2 is reacted with the surface functional groups of the base material 1 and the anion exchange latex 2. By fixing the anion exchange latex 2 by coating it with a crosslinkable polymer (latex fixing polymer layer 3), it is possible to produce a highly stable anion exchange resin without desorption of the anion exchange latex. It became possible. Further, the latex fixed polymer layer 3 is a three-dimensional crosslinkable polymer, and is used to cover the base material 1 with a strong shell.
The secondary effect was that the degree of swelling and contraction of the material was reduced and the pressure resistance was improved. Furthermore, the base material 1 and the anion exchange latex 2 (ion exchange group or resin itself) have hydrophilic groups, and the latex-fixed polymer layer 3 is also hydrophilic, making it a hydrophilic resin suitable for separating hydrophobic samples. Become.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a manufacturing method according to an example of the present invention, and FIG. 2 is a schematic diagram of an anion exchange resin manufactured according to the method of an example of the present invention. 1...Base material, 2...Anion exchange latex,
3... Latex fixed polymer layer.

Claims (1)

[Scope of Claims] 1. A crosslinkable polymer gel comprising a base material made of a resin having a sulfone group on its surface and a halogen group, a hydroxyl group, or an epoxy group, and a base material that is electrostatically bonded to the base material. anion exchange latex,
An anion exchange resin used in high performance liquid chromatography, etc., which is composed of a latex-immobilized polymer layer chemically bonded to the surface of the base material, is manufactured by the following steps (a) to (e). Characteristic method for producing anion exchange resin. (a) A process of preparing a polymer gel with sulfone groups, hydroxyl groups, halogen groups, or epoxy groups depending on the reaction method. (b) A step of dispersing the polymer gel in a small amount of an organic solvent, and then dispersing the ion exchange latex in the organic solvent. (c) Gradually adding the suspension of the ion exchange latex to the slurry of the polymer gel and stirring;
A step of mixing a polyfunctional epoxy compound that will become a fixed polymer layer into the slurry. (d) A step in which a reaction initiation catalyst is added and the reaction is carried out at a constant temperature for a certain period of time. (e) A process of washing with an organic solvent, then washing thoroughly with water, and then exchanging with the desired counterion. 2. The base material is sulfoalkylated polyhydroxyalkyl methacrylate, sulfoalkylated polyvinyl alcohol, sulfoalkylated polyglycidyl methacrylate, sulfoalkylated polyglycidyl ether, sulfoalkylated polymethylolstyrene, or sulfoalkylated polychloromethylstyrene. A method for producing an anion exchange resin according to claim 1. 3. The anion exchanger according to claim 1, wherein the ion exchange latex is an anion exchange resin having an anion exchange group, and is a latex having a reactive group consisting of a hydroxyl group or an epoxy group in the base material. Method of manufacturing resin.