KR102702039B1 - Method for preparing non-agglomerating anion exchange resin and non-agglomerating anion exchange resin prepared thereby - Google Patents

Abstract

The present invention relates to a method for producing a non-coagulant anion exchange resin and a non-coagulant anion exchange resin produced thereby. More specifically, the present invention relates to a method for producing a non-coagulant anion exchange resin and a non-coagulant anion exchange resin produced thereby, which can provide a regenerable mixed-bed ion exchange resin that does not cause coagulation and exhibits excellent separation ability even after repeated long-term passage and regeneration during water purification.

Description

Method for preparing non-agglomerating anion exchange resin and non-agglomerating anion exchange resin prepared thereby

The present invention relates to a method for producing a non-coagulant anion exchange resin and a non-coagulant anion exchange resin produced thereby. More specifically, the present invention relates to a method for producing a non-coagulant anion exchange resin and a non-coagulant anion exchange resin produced thereby, which can provide a regenerable mixed-bed ion exchange resin that does not cause coagulation and exhibits excellent separation ability even after repeated long-term passage and regeneration during water purification.

Recently, in the semiconductor manufacturing field, with the increase in integration of semiconductor devices, there is a demand for drastically higher purity of water as well as production machines, gases, and chemicals used in the manufacturing process, and very high purity water such as ultrapure water (sometimes also called ultrapure water) is also required.

As one step to obtain such high-purity water, there is a process that uses a mixed bed type ion exchange resin that mixes a cation exchange resin and an anion exchange resin, and the mixed bed type ion exchange resin can be divided into a regeneration type that is used through periodic regeneration and a non-regeneration type that is used once without regeneration. In general, the former is positioned after relatively low water quality (resistivity: 0.1 to 1 MΩ cm) during purification and is used to additionally remove ions in the water, and the latter is positioned after ultra-pure water (resistivity: 15 to 18 MΩ cm) and is used to ultimately remove ions that exist in extremely small amounts. In order to regenerate the regenerated mixed bed type ion exchange resin after water collection is complete, the cation exchange resin and anion exchange resin must first be separated through backwashing. However, cation exchange resins and anion exchange resins have a problem in that they cannot be completely separated from each other because they are combined by electrical attraction due to their opposite surface charges, causing a coagulation phenomenon. If separation is not completely achieved during regeneration of a regenerative mixed-bed ion exchange resin, a problem occurs in which the amount of water collected is drastically reduced due to reverse regeneration.

In general, the regenerative mixed-bed ion exchange resin in the production of ultrapure water processes cation exchange resins, anion exchange resins, and pure water with a resistivity of 0.1 to 1 MΩ cm that has passed through a reverse osmosis (RO) device. As the quality of the pure water to be treated decreases, the coagulation phenomenon of the mixed-bed ion exchange resin decreases and the separation performance increases. This is because the organic components and multivalent ion components contained in the low quality water are adsorbed to the ion exchange resin and the surface charge is reduced. However, due to the recent development and advancement of the ultrapure water production process, there are cases where the water quality in front of the regenerative mixed-bed ion exchange resin has a resistivity of 1 MΩ cm or higher. In this case, the organic components in the water quality have already been reduced to the level of several to several tens of ppb (parts per billion), and the impurity ions are extremely small, so contamination of the ion exchange resin due to impurities in the water quality and the resulting decrease in surface charge and increase in separation performance cannot be expected. In fact, in the case of the latest ultra-pure water manufacturing facilities, an additional process is introduced to induce forced layer separation through pre-chemical treatment due to the decline in the separation properties of regenerative mixed-bed ion exchange resins, which results in the use of additional chemicals and increased operating costs.

Various methods have been attempted to prevent aggregation and increase the separability of such regenerative mixed-phase ion exchange resins. U.S. Patent No. 6,060,526 describes a method of treating an anion exchange resin with a polysulfonated poly(vinyl aromatic) polyelectrolyte having a number average molecular weight of 5,000 to 1,000,000. In this method, a water-soluble polyelectrolyte having a specific molecular weight was used in a specific treatment amount in order to prevent aggregation and deterioration of the performance of the ion exchange resin due to the water-soluble polyelectrolyte. However, if passage and regeneration are repeated, the polymer electrolyte is desorbed, making it easy for aggregation to form again. Japanese Patent No. 5,567,539 describes a method for producing a cation exchange resin that maintains a high exchange rate without aggregation by treating the cation exchange resin with a water-soluble cationic polymer electrolyte having an intramolecular cyclic quaternary ammonium salt structure. However, this also causes the polymer electrolyte to be desorbed due to repeated passage and regeneration, and it is difficult to maintain excellent separation for a long period of time when processing a relatively high-purity inlet with a resistivity of 1 MΩ cm or more.

Therefore, there is a demand for a technology for manufacturing a regenerative mixed-phase ion exchange resin that does not cause coagulation when further refining pure water having a resistivity of 1 MΩ cm or higher and can exhibit excellent separation ability even after long-term passage and repetition.

The purpose of the present invention is to provide a method for producing a non-coagulant anion exchange resin capable of providing a regenerative mixed-phase ion exchange resin that exhibits excellent separation ability without causing coagulation even after repeated long-term passage and regeneration in further purifying pure water having a resistivity of 1 MΩ cm or more, and a non-coagulant anion exchange resin produced thereby.

In order to solve the above technical problem, the present invention provides a method for producing a non-aggregating anion exchange resin, comprising the steps of: (1) contacting a strongly basic anion exchange resin with an alkaline hydroxide aqueous solution having a concentration of 2 wt% or more and then heating the same to a temperature of 55° C. or higher; and (2) contacting the anion exchange resin obtained in step (1) with an anionic polymer electrolyte and then heating the same to a temperature of 35° C. or higher.

According to another aspect of the present invention, a non-aggregating anion exchange resin is provided, which is manufactured by the method of the present invention and has an anionic polymer electrolyte coating on its surface.

According to another aspect of the present invention, a regenerable mixed-bed ion exchange resin comprising the non-coagulant anion exchange resin of the present invention is provided.

The regenerable mixed-bed ion exchange resin composed of the non-coagulant anion exchange resin of the present invention and a cation exchange resin can exhibit excellent separation ability without causing coagulation even after repeated long-term passage and regeneration when used for additional purification of pure water having a resistivity of 1 MΩ cm or more, and is therefore very useful for producing ultrapure water.

Hereinafter, the present invention will be described in more detail.

The method for producing a non-coagulant anion exchange resin of the present invention comprises the step of (1) contacting a strongly basic anion exchange resin with an aqueous alkali hydroxide solution having a concentration of 2 wt% or more and then heating the same to a temperature of 55°C or more.

As the above-mentioned strong basic anion exchange resin, a typical strong basic anion exchange resin can be used, and for example, a chloride type (Cl type) or hydroxide type (OH type) strong basic anion exchange resin can be used. In the case of the Cl type, it can be used after being converted to the OH type using an alkali hydroxide aqueous solution of an appropriate concentration before performing the above-mentioned step (1).

In one specific example, the strong basic anion exchange resin has a quaternary ammonium group as an exchange group, and the parent may be a crosslinked polymer obtained by polymerizing a monovinylidene aromatic monomer (e.g., styrene, etc.) and a crosslinking agent (e.g., divinylbenzene, etc.).

More specifically, commercial examples of the strong alkaline anion exchange resin include, but are not limited to, TRILITE (trade name) MA12OHUP, TRILITE (trade name) MA10OHUP, and TRILITE (trade name) MA15OHUP manufactured by Samyang Corporation.

In one specific example, the average particle size of the strongly basic anion exchange resin may be 0.05 to 2.0 mm, and more specifically, 0.1 to 1.0 mm, when considering the pressure loss and ion exchange rate, but is not limited thereto.

The above alkali hydroxide aqueous solution is used to reduce the surface charge of a strongly basic anion exchange resin. In one specific example, the alkali hydroxide can be sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, or a combination thereof.

The above alkali hydroxide aqueous solution has a concentration of 2 wt% or more. If the concentration of the alkali hydroxide aqueous solution is less than 2 wt%, the cohesion of the resulting anion exchange resin increases, making it difficult or impossible to separate it from the cation exchange resin during regeneration of the mixed-phase ion exchange resin containing it.

More specifically, the concentration of the alkali hydroxide aqueous solution may be 2 wt% or more, 2.5 wt% or more, 3 wt% or more, or 3.5 wt% or more, but is not limited thereto. The concentration of the alkali hydroxide aqueous solution has no particular limitation in its upper limit, but it is not preferable that it be excessively high, and for example, it may be 10 wt% or less, 9 wt% or less, 8 wt% or less, 7 wt% or less, or 6 wt% or less, but is not limited thereto.

In the above step (1), the mixture of the strong basic anion exchange resin and the alkaline hydroxide aqueous solution is heated to a temperature of 55°C or higher. If the heating temperature is lower than 55°C, the cohesiveness of the resulting anion exchange resin increases, making it difficult to separate it from the cation exchange resin during regeneration of the mixed-phase ion exchange resin containing it.

More specifically, the heating temperature in the step (1) may be, but is not limited to, 55°C or higher, 60°C or higher, 65°C or higher, 70°C or higher, 75°C or higher, or 80°C or higher. The heating temperature in the step (1) has no particular limitation on its upper limit, but it is not preferable that it be excessively high, and for example, may be, but is not limited to, 100°C or lower, 95°C or lower, or 90°C or lower.

In one specific example, the heating of the mixture of the strongly basic anion exchange resin and the alkaline hydroxide aqueous solution in the step (1) may be maintained for, for example, 1 to 12 hours, more specifically 2 to 10 hours, and even more specifically 2 to 6 hours, but is not limited thereto. If the heating time is too long, there is a concern that the exchange capacity may decrease due to unintended deterioration of the resin, and conversely, if it is too short, the effect of reducing the surface charge cannot be expected.

The contact of the above-mentioned strong basic anion exchange resin with the alkaline hydroxide aqueous solution may be in a batch manner or a column manner, and is preferably in a batch manner. In the case of a batch manner, the amount of the alkaline hydroxide aqueous solution may be 2 to 3 BV (bed volume) with respect to the ion exchange resin, and although a larger amount may be used, additional costs and processes are required to treat the remaining alkaline hydroxide aqueous solution, which is inefficient in terms of the process.

When contacting in a column manner, it is preferable to heat the alkali hydroxide aqueous solution to the above temperature and pass it downward through the resin. At this time, the amount of the alkali hydroxide aqueous solution can be 5 to 15 BV with respect to the ion exchange resin, and the passage speed can be 5 to 10 hr ^-1 in space velocity (hereinafter abbreviated as SV). If the space velocity is too low, the alkali hydroxide aqueous solution passing through the column cools down, reducing the treatment effect, and if it is too high, the amount of alkali hydroxide aqueous solution that must be used increases, which is inefficient in terms of the process.

When the strongly basic anion exchange resin is brought into contact with an alkaline hydroxide aqueous solution and subjected to a heat treatment as in the above step (1), some of the exchange groups (e.g., quaternary ammonium groups) on the surface of the resin are deteriorated, resulting in a decrease in surface charge. After the heat treatment, the resulting anion exchange resin can be washed with water (e.g., repeatedly washed with pure water) to remove all alkaline hydroxide remaining on the surface.

The method for producing a non-aggregating anion exchange resin of the present invention comprises the step (2) of bringing the anion exchange resin obtained in step (1) into contact with an anionic polymer electrolyte and then heating it to a temperature of 35°C or higher.

As the above anionic polymer electrolyte, any polymer electrolyte commonly known to be usable for treating anion exchange resins can be used without any particular limitation.

In one specific embodiment, the anionic polymer electrolyte can be sulfonated polystyrene, polyacrylic acid, polymethacrylic acid, polymaleic anhydride or a combination thereof, preferably linear sulfonated polystyrene.

In one specific example, the weight average molecular weight (Mw, g/mol) of the anionic polymer electrolyte may be 10,000 to 3,000,000, more specifically 20,000 to 1,000,000, and even more specifically 50,000 to 100,000, but is not limited thereto.

In the above step (2), the mixture of the anion exchange resin and the anionic polymer electrolyte is heated to a temperature of 35°C or higher. If the heating temperature is lower than 35°C, the cohesiveness of the resulting anion exchange resin increases, making it difficult or impossible to separate the resulting mixed-phase ion exchange resin from the cation exchange resin during regeneration.

More specifically, the heating temperature in the step (2) may be 35°C or higher, 40°C or higher, 45°C or higher, or 50°C or higher, but is not limited thereto. The heating temperature in the step (2) has no particular limitation on its upper limit, but it is not preferable that it be excessively high, and for example, it may be 100°C or lower, 95°C or lower, 90°C or lower, 85°C or lower, or 80°C or lower, but is not limited thereto.

In one specific example, the amount of the anionic polymer electrolyte contacted per 1 L of the anion exchange resin obtained in step (1) may be, for example, 40 mg or more, 45 mg or more, 50 mg or more, or 55 mg or more, and may also be 900 mg or less, 800 mg or less, 700 mg or less, or 600 mg or less, but is not limited thereto.

In one specific example, the heating of the mixture of the anion exchange resin and the anionic polymer electrolyte in the step (2) may be maintained for, for example, 1 to 12 hours, more specifically 2 to 10 hours, and even more specifically 2 to 6 hours, but is not limited thereto. If the heating time is too long, there is a concern that the exchange capacity may decrease due to unintended deterioration of the resin, and conversely, if it is too short, the coating of the anionic polymer electrolyte may be insufficient.

After the heat treatment in the above step (2), the resulting anion exchange resin can be washed with water (e.g., repeatedly washed with pure water) to remove all unreacted anionic polymer electrolyte.

The anion exchange resin that has undergone steps (1) and (2) described above has an anionic polymer electrolyte coating on its surface and exhibits non-coagulation.

Therefore, according to another aspect of the present invention, a non-coagulant anion exchange resin is provided, which is manufactured by the method of the present invention and has an anionic polymer electrolyte coating on its surface.

In addition, according to another aspect of the present invention, a regenerable mixed-bed ion exchange resin comprising the non-coagulant anion exchange resin of the present invention is provided.

In one specific example, the regenerative mixed-phase ion exchange resin may contain the non-aggregating anion exchange resin of the present invention as an anion exchange resin and the strongly acidic cation exchange resin as a cation exchange resin.

As the above-mentioned strong acid cation exchange resin, a typical strong acid cation exchange resin can be used, and for example, a hydrogen ion type (H type) or sodium type (Na type) strong acid cation exchange resin can be used. In the case of the Na type, it can be used after being converted to the H type using an acid aqueous solution of an appropriate concentration before being used in the mixed-phase ion exchange resin.

In one specific example, the strong acid cation exchange resin has a sulfonic acid group as an exchange group, and the parent polymer may be a crosslinked polymer obtained by polymerizing a monovinylidene aromatic monomer (e.g., styrene, etc.) and a crosslinking agent (e.g., divinylbenzene, etc.).

More specifically, commercial examples of the strong acid cation exchange resin include, but are not limited to, TRILITE (trade name) MC08HUP, TRILITE (trade name) MC10HUP, and TRILITE (trade name) MC14HUP manufactured by Samyang Corporation.

In one specific example, the average particle size of the strong acid cation exchange resin may be 0.05 to 2.0 mm, and more specifically 0.1 to 1.0 mm, when considering the pressure loss and ion exchange rate, but is not limited thereto.

The ratio of the cation exchange resin and the anion exchange resin in the above-mentioned regenerative mixed-bed ion exchange resin can be arbitrarily adjusted according to the ion composition of the water quality to be treated. For example, in the case of RO post-stage water, since the ratio of anions is high, it is common to use a higher ratio of anion exchange resin, and the ratio can be 10/1 to 1/1 as the volume ratio of anion exchange resin/cation exchange resin, and more specifically, can be 4/1 to 2/1.

Hereinafter, the present invention will be described in more detail through examples and comparative examples. However, the scope of the present invention is not limited thereto.

[Example]

Example 1

Preparation of non-coagulant anion exchange resin

(1) 1.5 L of a strongly basic anion exchange resin (TRILITE MA10OHUP, manufactured by Samyang Corporation) was placed in a 5 L reactor, 3 L of a 4% NaOH aqueous solution was added, and the temperature was raised to 100°C while stirring. The temperature was maintained for 3 hours and then cooled to room temperature (25°C). After that, the filtrate of the NaOH aqueous solution was drained, 3 L of ultrapure water was added to the reactor, and stirred for 30 minutes. After that, the ultrapure water was drained, and an additional 3 L of ultrapure water was added to the reactor, and stirred for 30 minutes.

(2) Next, 1.5 L of the ion exchange resin obtained in (1) was placed in a 5 L reactor, and 3 L of ultrapure water was added. Thereafter, 500 mg of a sulfonated polystyrene aqueous solution (Poly(4-styrenesulfonic acid) water solution, Merck) (Mw: approximately 75,000, 18 wt.%) as an anionic polymer electrolyte was added (90 mg of anionic polymer electrolyte as solid content per 1 L of resin). Thereafter, the mixture was stirred and the temperature was increased to 60°C, maintained at the temperature for 3 hours, and then cooled to room temperature. Thereafter, the filtrate was drained, and 3 L of ultrapure water was added to the reactor, followed by stirring for 30 minutes. Thereafter, the ultrapure water was drained, and an additional 3 L of ultrapure water was added to the reactor, followed by stirring for 30 minutes.

Preparation of mixed phase ion exchange resin and primary coagulation test

The pure water mentioned in this embodiment and hereinafter refers to a pure water having a purity of 1.0 to 1.5 MΩ cm resistivity, and refers to a pure water manufactured through the following process. Pure water having a purity of 1.0 to 1.5 MΩ cm resistivity is manufactured by sequentially passing industrial water through a strongly acidic cation exchange resin, a degasifier, a strongly basic anion exchange resin, a heat exchanger, a first reverse osmosis membrane (RO), and a second RO. However, the method for manufacturing pure water is not limited to the above method.

1 L of strongly acidic cation exchange resin (TRILITE MC10HUP, Samyang Corporation) was added to an acrylic column (length (L) 200 cm x diameter (D) 10 cm) using pure water, and the resin layer was compacted and settled without any gaps. The height of the cation exchange resin was then measured, which is called the “initial cation resin layer height.”

The strongly basic anion exchange resin coated with the anion polymer electrolyte obtained in the above (2) was additionally introduced into the column using pure water and allowed to settle. The cation exchange resin and the anion exchange resin were mixed by injecting air from the bottom of the column for 5 minutes (hereinafter this operation is referred to as “Air Mixing”). After 5 minutes, the air injection was stopped, the mixed resin was allowed to settle, and then backwashed using pure water at a flow rate of 1.2 L/min for 15 minutes (hereinafter this operation is referred to as “backwashing”). After the backwashing was completed, the resin layers were compacted well and allowed to settle without any gaps. The cation exchange resin was located at the bottom, and the anion exchange resin was located at the top. At this time, the height of the cation exchange resin layer was measured, which is referred to as the “cation resin layer height after backwashing.” The degree of primary coagulation was calculated as “cation resin layer height after backwashing” / “initial cation resin layer height” * 100. The closer the calculated value of the first degree of coagulation is to 1, the less coagulation there is and the better the separation ability is.

Evaluation of the first water and regeneration cycle, and the second coagulation test

After the first coagulation test, continuous air mixing was performed, and then pure water was used to pass water in a downward direction for 20 days at a flow rate of 50 times the resin volume per hour (hereinafter, this operation is referred to as “Service”). The outlet water quality was measured as a resistivity value using a Mettler Toledo resistivity meter M300 just before the end of the passage. After the end of the passage, backwash was performed, and the resin layer was compacted and settled without any gaps. The height of the cation exchange resin layer was measured, which is referred to as “cation resin layer height after first passage.” The secondary coagulation degree was calculated as “cation resin layer height after first passage”/“cation resin layer height after backwash”*100. The closer the calculated value of the secondary coagulation degree is to 1, the less coagulation there is and the better the separation ability is. Next, regeneration was performed using the following method (hereinafter, this operation is referred to as “regeneration”).

The cation exchange resin and anion exchange resin were separated by reverse filtration with deionized water. The anion exchange resin was recovered through the top of the column while slowly increasing the flow rate. Finally, all of the anion exchange resins were recovered, and the cation exchange resins were left inside the column. Each ion exchange resin was transferred to an acrylic column (L 200 cm X D 7.5 cm) using deionized water. The anion exchange resin was regenerated by flowing 1.75 BV of a 4% NaOH aqueous solution downward at a flow rate of SV=4 hr ^-1 . Then, it was washed with deionized water at a flow rate of SV=20 hr ^-1 for 1 hour. The cation exchange resin was regenerated by flowing 2.5 BV of a 4% HCl aqueous solution downward at a flow rate of SV=4 hr ^-1 . Then, it was washed with deionized water at a flow rate of SV=20 hr ^-1 for 1 hour.

Secondary water and regeneration cycle evaluation, and third coagulation test

After the secondary coagulation test, the regenerated resin was put into an acrylic column (L 200 cm x D 10 cm) and air mixing, service, resistivity measurement, and backwashing were performed. After the passage was completed and backwashed, the resin layer was compacted and settled without any gaps. The height of the cation exchange resin layer was measured and is called the “cation resin layer height after secondary passage.” The tertiary coagulation degree was calculated as “cation resin layer height after secondary passage”/“cation resin layer height after backwash”*100. The closer the calculated value of the tertiary coagulation degree is to 1, the less coagulation there is and the better the separation ability is. Next, regeneration was performed in the same way as in the 2nd coagulation test.

3rd water and regeneration cycle evaluation, and 4th coagulation test

After the 3rd coagulation test, the regenerated resin was put into an acrylic column (L 200 cm x D 10 cm) and air mixing, service, resistivity measurement, and backwashing were performed. After the passage was completed and backwashed, the resin layer was compacted and settled without any gaps. The height of the cation exchange resin layer was measured and is called the “cation resin layer height after 3rd passage.” The 4th coagulation degree was calculated as “cation resin layer height after 3rd passage”/“cation resin layer height after backwash”*100. The closer the calculated value of the 4th coagulation degree is to 1, the less coagulation there is and the better the separation ability.

Example 2

The method of Example 1 was carried out in the same manner as above, except that the method of contacting the anion exchange resin and the alkali hydroxide aqueous solution was changed from a batch method to a column method as follows, and then the 1st to 3rd coagulation tests were performed. The contact method using the column method was as follows.

1 L of strongly basic anion exchange resin was introduced into an acrylic column (L 200 cm x D 5 cm) using purified water. 10 L of a 4% NaOH aqueous solution was heated to 80 °C and introduced into the column at a flow rate of SV = 5 hr ^-1 using a quantitative pump. Thereafter, 20 times the volume of the resin, purified water, was introduced into the column at a flow rate of SV = 5 hr ^-1 to completely remove the NaOH aqueous solution.

Example 3

Except that 4% NaOH aqueous solution was added and the temperature was raised to 100°C and the holding time was set to 12 hours for the contact between the anion exchange resin and the alkali hydroxide aqueous solution, the same method as in Example 1 was carried out, and then the 1st to 3rd coagulation tests were performed.

Example 4

Except that 5,000 mg of the anionic polymer electrolyte (900 mg of the anionic polymer electrolyte as solid content per 1 L of resin) was added to the anionic exchange resin treated with an alkaline hydroxide aqueous solution and the anionic polymer electrolyte, the same method as in Example 1 was carried out, and then the 1st to 3rd coagulation tests were performed.

Example 5

Except that the pure water quality used for the evaluation of the water flow and regeneration cycle and the coagulation test was replaced with water having a purity of 0.1 MΩ cm, the same method as Example 1 was followed, and the 1st to 3rd coagulation tests were performed.

Comparative Example 1

Except that a 1.8% concentration NaOH aqueous solution was used for the contact between the anion exchange resin and the alkali hydroxide aqueous solution, the same method as in Example 1 was followed, and the 1st to 3rd coagulation tests were performed.

Comparative Example 2

Except that a 1% concentration NaOH aqueous solution was used for the contact between the anion exchange resin and the alkali hydroxide aqueous solution, the same method as in Example 1 was followed, and the 1st to 3rd coagulation tests were performed.

Comparative Example 3

Except that the temperature was increased to 50°C after adding 4% NaOH aqueous solution for contact between the anion exchange resin and the alkali hydroxide aqueous solution, the same method as in Example 1 was followed, and the 1st to 3rd coagulation tests were performed.

Comparative Example 4

The same procedure as Example 1 was followed, except that the anion exchange resin and the alkali hydroxide aqueous solution were not brought into contact, and the 1st to 3rd coagulation tests were then performed.

Comparative Example 5

The same method as Example 1 was followed, except that the alkali hydroxide solution was stirred at room temperature (25°C) without heating after introduction of the alkali hydroxide solution in contact with the anion exchange resin, and the 1st to 3rd coagulation tests were then performed.

Comparative Example 6

The same procedure as Example 1 was followed, except that pure water was brought into contact with the anion exchange resin instead of an alkaline hydroxide solution, and the 1st to 3rd coagulation tests were then performed.

Comparative Example 7

The same procedure as in Example 1 was followed, except that the anion exchange resin treated with an alkaline hydroxide solution was not brought into contact with the anionic polymer electrolyte, and the 1st to 3rd coagulation tests were then performed.

Comparative Example 8

Except that the anionic polymer electrolyte was stirred at room temperature (25°C) without heating after introduction of the anionic polymer electrolyte when contacting the anion exchange resin treated with an aqueous alkaline hydroxide solution with the anionic polymer electrolyte, the same method as in Example 1 was carried out, and then the 1st to 3rd coagulation tests were performed.

The results of the coagulation test and resistivity of Examples 1 to 5 and Comparative Examples 1 to 8 are summarized in Table 1.

As shown in Table 1 above, the mixed-bed ion exchange resin manufactured by mixing the non-coagulant anion exchange resin manufactured in the examples with the cation exchange resin maintained separation ability without coagulation even after repeated numerous passage and regeneration cycles over a long period of time, thereby continuously obtaining high-purity water quality.

On the other hand, in the case of the mixed-bed ion exchange resin manufactured by mixing the anion exchange resin manufactured in the comparative examples with the cation exchange resin, the separation ability decreased due to the occurrence of a coagulation phenomenon during the repeated passage and regeneration processes, and as a result, the water quality of the final treated water deteriorated (resistance decreased). In particular, in the case of comparative examples 4 and 6 to 8, as the passage and regeneration were repeated, it became difficult to separate the cation exchange resin and the anion exchange resin, and thus the passage evaluation could not be performed after a certain point.

Claims (8)

(1) a step of contacting a strongly basic anion exchange resin with an alkaline hydroxide aqueous solution having a concentration of 2 wt% or more and then heating it to a temperature of 80°C or more; and
(2) a step of bringing the anion exchange resin obtained in the above step (1) into contact with an anionic polymer electrolyte and then heating it to a temperature of 50°C or higher;
A method for producing a non-coagulant anion exchange resin. A method in claim 1, wherein the alkali hydroxide is sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide or a combination thereof. A method in claim 1, wherein in step (1), the heating of a mixture of a strongly basic anion exchange resin and an alkaline hydroxide aqueous solution is maintained for 1 to 12 hours. A method in claim 1, wherein the anionic polymer electrolyte is sulfonated polystyrene, polyacrylic acid, polymethacrylic acid, polymaleic anhydride or a combination thereof. A method in claim 1, wherein the amount of anionic polymer electrolyte contacted per 1 L of the anion exchange resin obtained in step (1) is 40 mg to 900 mg. A non-aggregating anion exchange resin having an anionic polymer electrolyte coating on its surface, manufactured by the method of any one of claims 1 to 5. A regenerative mixed-phase ion exchange resin comprising a non-coagulant anion exchange resin of claim 6. In claim 7, a regenerative mixed-phase ion exchange resin for purifying pure water having a resistivity of 1 MΩ cm or more.