KR20230091247A - Method for preparing cation exchange resin with reduced impurities and cation exchange resin prepared thereby - Google Patents

Abstract

The present invention relates to a method for preparing a cation exchange resin and a cation exchange resin prepared thereby, and more specifically, to a method for preparing a cation exchange resin which has an extremely low content of impurities such as organic carbon and metals so as to be particularly suitable for use in the preparation of ultrapure water for semiconductors, and a cation exchange resin prepared thereby. The method for preparing a cation exchange resin according to the present invention comprises a step (1) of treating a strongly acidic cation exchange resin with an alkali metal hydroxide at a temperature higher than room temperature; a step (2) of treating the cation exchange resin obtained in the step (1) with an aqueous mineral acid solution at a temperature higher than room temperature; and a step (3) of washing the cation exchange resin obtained in the step (2) with ultrapure water.

Description

Method for preparing cation exchange resin with reduced impurities and cation exchange resin prepared thereby {Method for preparing cation exchange resin with reduced impurities and cation exchange resin prepared thereby}

The present invention relates to a method for producing a cation exchange resin and to a cation exchange resin prepared thereby, and more particularly, to a cation that can be used particularly suitably for the production of ultrapure water for semiconductors with extremely low content of impurities such as organic carbon and metal. It relates to a method for preparing an exchange resin and a cation exchange resin prepared thereby.

In recent years, in the field of semiconductor manufacturing, with the high integration of semiconductor elements, there is a demand for significantly higher purity of water as well as production machines, gases, chemicals, etc. applied in the semiconductor manufacturing process. ), etc., are also required for very high purity water.

Electricity/electronics produced when a large amount of various metal ions, such as sodium ions, calcium ions, magnesium ions, iron ions, copper ions, and zinc ions, which are ionic impurities, are included in washing water such as ultrapure water or various liquid agents represented by resist liquid. It can cause a great adverse effect on the quality of the product. For this reason, liquids used in the manufacture of electrical/electronic products are required to be of high purity, containing almost no impurities and metal ions, and liquids containing little metal ions are purified by ion exchange resins. However, when a large amount of metal impurities are included in the ion exchange resin, metal ions are eluted into the liquid agent, making it difficult to obtain a high-purity liquid agent.

Japanese Patent Laid-open Publication No. 07-117781 discloses that an aqueous solution of a high-purity mineral acid having a metal impurity content of 1 mg/L (ppm or less) is passed downwardly through an ion exchange resin containing metal ions to obtain metal ion impurities in the ion exchange resin. A method of reducing the quantity is disclosed. However, in this method, the high-purity mineral acid solution having an impurity metal ion content of 1 mg/L or less is very expensive due to an additional purification process, and in addition, in the purification operation of the ion exchange resin, the pump or pipe in contact with the mineral acid solution is also metal. Since a coating of a special material that is not contaminated by ions must be included, high cost is incurred in constructing an ion exchange resin purification device, and cost and difficulty are also incurred in maintaining and managing such an expensive device so as not to be contaminated. causes In addition, in the process of passing a large amount of high-purity mineral acid aqueous solution, the amount of treatment liquid generated increases, and costs for neutralization treatment/disposal of the generated treatment liquid may also occur.

Therefore, there is a need for a more economical method capable of reducing the content of impurities such as metal ions in cation ion exchange resins so that they can be used in the production of ultrapure water for semiconductors.

An object of the present invention is to provide a method for producing a cation exchange resin that can be used particularly suitably for the production of ultrapure water for semiconductors with extremely low content of impurities such as organic carbon and metal, and a cation exchange resin prepared thereby.

In order to solve the above technical problem, the present invention includes (1) treating a strongly acidic cation exchange resin with an alkali metal hydroxide at a temperature higher than room temperature; (2) treating the cation exchange resin obtained in step (1) with an aqueous mineral acid solution at a temperature higher than room temperature; and (3) washing the cation exchange resin obtained in step (2) with ultrapure water.

According to another aspect of the present invention, a cation exchange resin prepared according to the method of the present invention is provided.

The cation exchange resin prepared according to the method of the present invention has extremely low content of impurities such as organic carbon and metal, so when used for water purification, the content of metal impurities is low, total organic carbon (TOC) elution is low, and purified water with excellent resistivity value It can provide, and, therefore, it can be used particularly suitably for the production of ultrapure water for semiconductors.

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

The method for preparing the cation exchange resin of the present invention includes (1) treating the strongly acidic cation exchange resin with an alkali metal hydroxide at a temperature higher than room temperature.

As the strong acid cation exchange resin, a general strong acid cation exchange resin may be used, and for example, a hydrogen ion type (H type) or sodium type (Na type) strong acid cation exchange resin may be used. In the case of the Na type, it may be used after converting to the H type using an aqueous acid solution of an appropriate concentration before using it in the mixed bed type ion exchange resin.

In one embodiment, the strong acidic cation exchange resin has a sulfonic acid group as an exchange group, and the matrix may be a crosslinked polymer obtained by polymerizing a monovinylidene aromatic monomer (eg, styrene, etc.) and a crosslinking agent (eg, divinylbenzene, etc.) .

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

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

In one embodiment, the alkali metal hydroxide may be selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, or a combination thereof, preferably sodium hydroxide. The alkali metal hydroxide may be used in the form of an aqueous solution.

In one embodiment, when the alkali metal hydroxide is used in the form of an aqueous solution, the content of the alkali metal hydroxide may be, for example, 1 to 10% by weight. More specifically, the alkali metal hydroxide content of the alkali metal hydroxide aqueous solution may be, for example, 1% by weight or more, 1.5% by weight or more, 2% by weight or more, or 2.5% by weight or more, and also 10% by weight or less, 9% by weight or less. It may be less than or equal to 8% by weight, less than or equal to 7% by weight or less than or equal to 6% by weight, but is not limited thereto.

In one embodiment, when the alkali metal hydroxide is used in the form of an aqueous solution, the amount used may be, for example, 1 to 5 times the volume of the cation exchange resin. More specifically, the amount of the alkali metal hydroxide aqueous solution used may be, for example, 1 time or more, 1.5 times or more, or 2 times or more, and may be 5 times or less, 4 times or less, or 3 times or less, based on the volume of the cation exchange resin. However, it is not limited thereto.

In one embodiment, the step (1) may be performed at a temperature higher than room temperature (25°C), for example, at a temperature of 55°C or higher. More specifically, the temperature at which step (1) is performed may be 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, but is not limited thereto. The temperature at which step (1) is performed is not particularly limited in its upper limit, but is not preferably too high. It doesn't work.

In one embodiment, the time during which the temperature is maintained higher than room temperature in step (1) may be, for example, 1 to 12 hours, more specifically 2 to 10 hours, and more specifically 2 to 6 hours. may, but is not limited thereto.

In the above step (1), the contact between the strongly acidic cation exchange resin and the aqueous alkali metal hydroxide solution may be performed in a batch method or a column method, preferably in a batch method. In the case of the batch method, the amount of the alkali metal hydroxide aqueous solution may be 2 to 3 BV (bed volume) for the ion exchange resin, and a larger amount may be used, but additional costs and processes are required to treat the used alkali metal hydroxide aqueous solution Therefore, the process is inefficient.

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

After the treatment in step (1), the resultant cation exchange resin may be washed with water (eg, repeatedly washed with pure water).

The method for producing a cation exchange resin of the present invention includes (2) treating the cation exchange resin obtained in step (1) with an aqueous acid solution at a temperature higher than room temperature.

In one embodiment, the mineral acid may be selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, preferably hydrochloric acid that is easy to handle at low cost.

In one embodiment, the acid acid content of the aqueous acid acid solution may be, for example, 1 to 10% by weight. More specifically, the acid acid content of the aqueous acid solution may be, for example, 1% by weight or more, 1.5% by weight or more, 2% by weight or more, or 2.5% by weight or more, and also 10% by weight or less, 9% by weight or less, It may be 8% by weight or less, 7% by weight or less, or 6% by weight or less, but is not limited thereto. When the concentration of the mineral acid is too high, it is undesirable because the equipment used for treating the ion exchange resin may be corroded by the acid or cause decomposition of chemical bonds constituting the ion exchange resin.

In one embodiment, the amount of the aqueous acid solution used may be, for example, 1 to 5 times the volume of the cation exchange resin. More specifically, the amount of the aqueous acid solution used may be, for example, 1 time or more, 1.5 times or more, or 2 times or more, and may be 5 times or less, 4 times or less, or 3 times or less, based on the volume of the cation exchange resin. Not limited to this.

In one embodiment, the total metal impurity content of the aqueous mineral acid solution may be, for example, 0.01 mg/L to 10 mg/L, more specifically 0.01 mg/L to 5 mg/L, more specifically 0.01 mg /L to 3 mg/L. When the total metal impurity content of the aqueous acid acid solution is higher than the above level, the metal impurities in the ion exchange resin cannot be reduced, and conversely, the metal impurities in the aqueous mineral acid solution may be adsorbed to the resin.

In one embodiment, the step (2) may be performed at a temperature higher than room temperature (25°C), for example, at a temperature of 30°C or higher. More specifically, the temperature at which step (1) is performed may be 30 °C or higher, 31 °C or higher, 32 °C or higher, or 33 °C or higher, but is not limited thereto. The temperature at which step (2) is performed is not particularly limited in its upper limit, but is not preferably too high, and may be, for example, 55 ° C or less, 50 ° C or less, 45 ° C or less, or 40 ° C or less, but is not limited thereto.

In one embodiment, the time during which the temperature is maintained higher than room temperature in step (2) may be, for example, 1 to 12 hours, more specifically 2 to 10 hours, and more specifically 2 to 6 hours. may, but is not limited thereto.

In the step (2), the contact between the cation exchange resin and the aqueous acid acid solution may be performed in a batch method or a column method, preferably in a batch method. In the case of the batch method, the amount of the aqueous acid solution may be 2 to 3 BV (bed volume) for the ion exchange resin, and a larger amount may be used, but it is inefficient in the process because additional costs and processes are required to treat the remaining aqueous acid solution. am.

In the case of contacting in a column manner, it is preferable to heat the aqueous acid solution to the above temperature and pass it through the resin in a downward flow. At this time, the amount of the aqueous acid acid solution may be 5 to 15 BV with respect to the ion exchange resin, and the liquid passing rate may be 5 to 10 hr ^-1 in terms of space velocity (hereinafter abbreviated as SV). If the space velocity is too low, the aqueous acid solution passing through the column cools down and the treatment effect is reduced.

After the treatment in step (2), the resultant cation exchange resin may be washed with water (eg, repeatedly washed with pure water).

The method for preparing the cation exchange resin of the present invention includes (3) washing the cation exchange resin obtained in step (2) with ultrapure water.

In one embodiment, in the step (3), ultrapure water having a total organic carbon (TOC) of 1 μg/L (ppb) or less and a specific resistance of 18.2 MΩ·cm or more may be used.

In one embodiment, in the step (3), ultrapure water is passed through the resin in a downward flow for about 15 to 20 hours at a flow rate of about SV = 20 hr ^-1 to remove mineral acids and organic substances and at the same time prevent recontamination of metal impurities. can

According to another aspect of the present invention, a cation exchange resin prepared according to the method of the present invention is provided.

The cation exchange resin of the present invention, which has undergone the steps (1) to (3) described above, has extremely low content of impurities such as organic carbon and metal, so when used for water purification, the content of metal impurities is low and the elution of total organic carbon (TOC) is low. And, it is possible to provide purified water having an excellent resistivity value, and therefore, it can be particularly suitably used for the production of ultrapure water for semiconductors.

In one embodiment, the cation exchange resin of the present invention may have a metal impurity (eg, sodium ion, calcium ion, magnesium ion, iron ion, copper ion, zinc ion, etc.) content of 5 mg/L or less, more specifically may be 4 mg/L or less, more specifically 3 mg/L or less.

In one embodiment, the cation exchange resin of the present invention can provide purified water having a total organic carbon (TOC) elution amount of 3 µg/L (ppb) or less and a specific resistance of 16 MΩ·cm or more.

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 cation exchange resins

(1) 200 ml of H-type strong acid cation exchange resin (TRILITE MC-08HUP) was put in a 1 L reactor made of Teflon, and then 2.5 times the volume of ion exchange resin, 3% by weight sodium hydroxide was added. Then, the temperature in the reactor was heated to 90° C., and the mixture was stirred while maintaining the temperature for 3 hours. Thereafter, the sodium hydroxide aqueous solution was drained, 2.5 times the volume of the ion exchange resin, ultrapure water was added to the reactor, stirred for 30 minutes, and the draining process was repeated three times.

(2) Put 200 ml of the cation exchange resin obtained in (1) in a 1 L reactor made of Teflon, and then add 2.5 times the volume of 3% by weight hydrochloric acid based on the volume of the ion exchange resin. It was heated to 35° C. and stirred while maintaining the temperature for 3 hours. Thereafter, the aqueous hydrochloric acid solution was drained, 2.5 times the volume of the ion exchange resin, ultrapure water was added to the reactor, stirred for 30 minutes, and the draining process was repeated three times.

(3) After filling 100 ml of the cation exchange resin obtained in (2) above in a column (length (L) 500 mm X diameter (D) 20 mm), total organic carbon (TOC) of 1 µg/L (ppb) or less, Ultrapure water having a specific resistance of 18.2 ㏁·cm or more was passed for 20 hours in a downward flow at a speed of SV = 20 hr ^-1 (volume ratio of fluid passing based on the volume of the ion exchange resin per unit time).

Resistivity and total organic carbon (TOC) evaluation

The organic carbon concentration was measured using a TOC analyzer (Anatel), and ultrapure water with a total organic carbon (TOC) of 0.5 to 1 μg/L (ppb) was applied to the column (L 500 mm X D 20 mm) downstream, SV = 30 hr ^-1 to 3 After passing the time, the resistivity and total organic carbon (TOC) of the treated water flowing out of the column were measured.

Evaluation of metal content in cation exchange resins

The metal impurities inside the ion exchange resin are eluted using high-purity analytical hydrochloric acid (with a metal impurity content of 1 mg/L or less) in the ion exchange resin using a glassware made of non-contaminated Teflon, and the eluent is Analysis was performed using ICP-MS. From this analysis value, the metal ion content per unit resin amount was calculated.

Comparative Example 1

In the step of treating the ion exchange resin with the metal hydroxide, the same method as in Example 1 was performed, except that the temperature in the reactor was maintained at room temperature. Then, in the same manner as in Example 1, resistivity and total organic carbon (TOC) elution were evaluated using ultrapure water, and metal content in the ion exchange resin was evaluated.

Comparative Example 2

Except for maintaining the temperature in the reactor at room temperature in the step of treating the ion exchange resin with metal hydroxide and maintaining the temperature in the reactor at room temperature in the step of treating the ion exchange resin with an aqueous acid acid solution, Example 1 and Proceeded in the same way. Then, in the same manner as in Example 1, resistivity and total organic carbon (TOC) elution were evaluated using ultrapure water, and metal content in the ion exchange resin was evaluated.

Comparative Example 3

Except that the ion exchange resin was not treated with metal hydroxide, the same procedure as in Example 1 was carried out. Then, in the same manner as in Example 1, resistivity and total organic carbon (TOC) elution were evaluated using ultrapure water, and metal content in the ion exchange resin was evaluated.

Comparative Example 4

The same procedure as in Example 1 was performed, except that the ion exchange resin was not treated with a metal hydroxide and was not treated with an aqueous acid acid solution. Then, in the same manner as in Example 1, resistivity and total organic carbon (TOC) elution were evaluated using ultrapure water, and metal content in the ion exchange resin was evaluated.

Comparative Example 5

The same procedure as in Example 1 was performed except that the ion exchange resin was not treated with metal hydroxide, was not treated with an aqueous acid acid solution, and was not washed with ultrapure water. Then, in the same manner as in Example 1, resistivity and total organic carbon (TOC) elution were evaluated using ultrapure water, and metal content in the ion exchange resin was evaluated.

Table 1 shows the evaluation results of resistivity and total organic carbon (TOC) elution using ultrapure water, and Table 2 shows the calculated metal ion content per unit resin amount of the ion exchange resin.

[Table 1]

[Table 2]

As can be seen from Table 1, the purified water that passed through the cation exchange resin prepared in Example 1 had a significantly lower total organic carbon (ΔTOC) effluent (2.9 μg/L (ppb) and As can be seen from Table 2, the cation exchange resin prepared in Example 1 had a significantly lower metal content than Comparative Examples 2 to 5.

Claims (8)

(1) treating the strongly acidic cation exchange resin with an alkali metal hydroxide at a temperature higher than room temperature;
(2) treating the cation exchange resin obtained in step (1) with an aqueous mineral acid solution at a temperature higher than room temperature; and
(3) washing the cation exchange resin obtained in step (2) with ultrapure water;
A method for producing cation exchange resins. The method of claim 1 , wherein the alkali metal hydroxide is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, or combinations thereof. The method of claim 1 , wherein step (1) is performed at a temperature of 55° C. or higher. The method of claim 1 , wherein the mineral acid is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid. The method of claim 1 , wherein step (2) is performed at a temperature of 30° C. or higher. The method according to claim 1, wherein ultrapure water having a water quality of 1 μg/L (ppb) or less of total organic carbon (TOC) and a specific resistance of 18.2 MΩ·cm or more is used in step (3). A cation exchange resin prepared by the method of any one of claims 1 to 6. The cation exchange resin according to claim 7, wherein the metal impurity content is 5 mg/L or less.