KR102346812B1 - Method for preparing ion exchange resin with reduced metal impurity content - Google Patents

Abstract

The present invention relates to a method for manufacturing an ion exchange resin with reduced metal impurity content, and more particularly, ultrapure water for semiconductors due to its extremely low content of metal ions, low total organic carbon (TOC) elution, and excellent resistivity. It relates to a method for preparing an ion exchange resin used in the manufacture of

Description

Manufacturing method of ion exchange resin with reduced metal impurity content {METHOD FOR PREPARING ION EXCHANGE RESIN WITH REDUCED METAL IMPURITY CONTENT}

The present invention relates to a method for manufacturing an ion exchange resin with reduced metal impurity content, and more particularly, ultrapure water for semiconductors due to its extremely low content of metal ions, low total organic carbon (TOC) elution, and excellent resistivity. It relates to a method for preparing an ion exchange resin used in the manufacture of

In recent years, in the field of semiconductor manufacturing, high purity has been required for cleaning and chemicals along with production machines and gases applied in the semiconductor manufacturing process along with the high integration of semiconductor devices, and ultrapure water used together (sometimes called extremely pure water). ), etc., are also increasing interest in very high-purity water.

Electricity produced when washing water such as ultrapure water or various liquid agents such as resist liquid contains 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. ·It may cause a great adverse effect on the quality of electronic products. For this reason, the liquid agent used for manufacturing electrical/electronic products is required to have high purity that hardly contains impurities and metal ions.

Liquid preparations with a low content of metal ions are being purified and manufactured 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.

In order to solve the problem caused by the metal contained in the above ion exchange resin, Japanese Patent Laid-Open No. 2007-117781 discloses a high-purity mineral acid in which the amount of metal impurities in the ion exchange resin containing metal ions is 1 mg/L (ppm) or less. Disclosed is a method for reducing the amount of impurities in metal ions in an ion exchange resin by flowing an aqueous solution in a downward flow. However, a mineral acid solution with a low content of impurity metal ions (a high purity mineral acid with an impurity content of 1 mg/L or less) is manufactured through an additional purification process, so it is very expensive. Since the pump or piping that is used for pumps and pipes must also contain a coating made of a special material that is not contaminated by metal ions, it is expensive to build an ion exchange resin purification device, and it is difficult to maintain and manage these devices so that they are not contaminated. . In addition, in the process of passing a large amount of high-purity aqueous solution of the mineral acid, the amount of treatment liquid is increased, and a cost loss for neutralization treatment/disposal treatment of the generated treatment liquid may occur.

For this reason, there is a need for a method capable of reducing the metal ion content in an ion exchange resin used for the production of ultrapure water for semiconductors at a low cost through a more economical treatment method.

The present invention is intended to solve the problems of the prior art as described above, and the content of metal ions is extremely low, the total organic carbon (TOC) elution is low, and the ion exchange resin used for the production of ultrapure water for semiconductors has excellent resistivity. The manufacturing method is a technical task.

The present invention in order to solve the above technical problem, (1) contacting the ion exchange resin and a mineral acid solution of 30 ℃ or more; and (2) washing the ion exchange resin obtained in step (1) with ultrapure water; wherein the total content of metal impurities in the washed ion exchange resin is 5 mg/LR or less, ion exchange with reduced metal impurity content A method for producing a resin is provided.

According to another aspect of the present invention, there is provided an ion exchange resin prepared by the above method.

The ion exchange resin (preferably a cation exchange resin, more preferably a strongly acidic cation exchange resin) prepared according to the method of the present invention has a very low content of metal impurities in the ion exchange resin itself, so the amount of eluted metal impurities is small, and total organic carbon It has low (TOC) dissolution and excellent resistivity, so it can be suitably used for manufacturing ultrapure water for semiconductors.

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

The present invention comprises the steps of (1) contacting an ion exchange resin with a mineral acid solution at 30° C. or higher; and (2) washing the ion exchange resin obtained in step (1) with ultrapure water; wherein the total content of metal impurities in the washed ion exchange resin is 5 mg/LR or less, ion exchange with reduced metal impurity content It relates to a method for producing a resin.

The ion exchange resin (preferably a cation exchange resin, more preferably a strongly acidic cation exchange resin) obtained by the production method of the present invention has a total organic carbon (TOC) elution amount of 5 ppb or less (preferably 4.5 ppb or less, more Preferably 4.3 ppb or less, more preferably 4.2 ppb or less), the specific resistance is 16 MΩ cm or more, and metallic impurities (sodium ions, calcium ions, magnesium ions, iron ions, copper ions) present in the ion exchange resin. and zinc ions) is 5 mg/LR (the amount of metal mg per unit volume of 1 L of the ion exchange resin in water-swelled state) or less (preferably 4 mg/LR or less, more preferably 3 mg/LR hereinafter) may be

The manufacturing method of the present invention includes the step of (1) contacting an ion exchange resin with a mineral acid solution of 30° C. or higher.

As the mineral acid solution used in step (1), an aqueous solution is preferable, and specific examples thereof include an aqueous hydrochloric acid solution, an aqueous sulfuric acid solution, an aqueous nitric acid solution, an aqueous phosphoric acid solution, or a mixed solution thereof, and an aqueous hydrochloric acid solution that is easy to handle at low cost It may be desirable to use

In step (1), the “contact” of the ion exchange resin with the photo acid solution includes passing the photo acid solution through the ion exchange resin as well as immersing the ion exchange resin in the photo acid solution. Preferably, the ion-exchange resin is brought into contact with the photo-acid solution by using a batch method in which the ion-exchange resin is brought into contact with the photo-acid solution and heated in step (1).

The ion exchange resin used in the production method of the present invention may be, for example, a strongly acidic cation exchange resin, a weakly acidic cation exchange resin, a strongly basic anion exchange resin or a weakly basic anion exchange resin, preferably a strongly acidic cation exchange resin. have. In addition, the ion exchange resin may be an ion exchange resin having an ion exchange group of Na type, H type or NH type, and preferably H type ion exchange resin may be used.

The content of the total metal impurities of the mineral acid solution used in step (1) may be 0.01 mg/L to 3 mg/L, and when the content of the total metal impurities of the mineral acid solution is 10 mg/L or more, the ion exchange resin It is not possible to reduce the metal impurities in the interior, and on the contrary, the metal impurities may be adsorbed to the ion exchange resin.

The temperature of the photoacid solution used in step (1) may be 30 °C or higher, for example, 35 °C or higher, 40 °C or higher, or 45 °C or higher. When the temperature of the photo-acid solution is less than 30° C., the expansion of the inside of the ion exchange resin is not performed properly, so that it is impossible to effectively remove the metal impurities present in the cross-linking. However, when the temperature of the mineral acid solution exceeds 50 ° C., the chemical bond constituting the ion exchange resin may be broken and the amount of total organic carbon emitted may increase, and cost may increase due to the temperature increase.

In the case of passing the photo-acid solution through the ion exchange resin, the temperature of the photo-acid solution is raised to 30° C. or higher, and then, by passing the photo-acid solution through the ion exchange resin, they can be brought into contact. After raising the temperature to 30 ℃ or more, or after raising the temperature of the mineral acid solution to 30 ℃ or more, the ion exchange resin may be immersed in the elevated temperature of the mineral acid solution.

The concentration of the mineral acid solution used in step (1) may be 1 to 10 wt%, for example, 1 wt% or more, 2 wt% or more, 3 wt% or more, or 4 wt% or more, and 10 wt% % or less, 8 wt% or less, 7 wt% or less, or 6 wt% or less. If the concentration of the mineral acid solution is too high, the equipment used for the treatment of the ion exchange resin may be corroded by acid or the chemical bonds constituting the ion exchange resin may be decomposed. , the effect of removing metal impurities may be insignificant.

The manufacturing method of the present invention includes the step of (2) washing the ion exchange resin obtained in step (1) with ultrapure water.

In step (2), the ion exchange resin obtained in step (1) is treated with ultrapure water having a total organic carbon (TOC) of 1 ppb or less and a specific resistance of 18.2 ㏁ cm or more, SV = 20 hr ^-1 to 30 hr ^{By passing the liquid downward for 15 to 20 hours at a flow rate of -1, it} is possible to remove the mineral acid solution and organic matter and to prevent re-contamination of metal impurities.

According to the method of the present invention, metal impurities in the ion exchange resin are removed by a simple operation of bringing the ion exchange resin into contact with a solution of a mineral acid heated to 30° C. or higher in a reactor, so that metal impurities that can be eluted when the ion exchange resin is used. It is possible to reduce metallic impurities, and it is possible to prepare a high-quality ion exchange resin having a low total organic carbon (TOC) elution and a high specific resistance.

The present invention also relates to an ion exchange resin produced by the method of the present invention.

The ion exchange resin prepared according to the production method of the present invention has a total organic carbon (TOC) elution amount of 5 ppb or less (preferably 4.5 ppb or less, more preferably 4.3 ppb or less, even more preferably 4.2 ppb or less) , the specific resistance may be 16 MΩ cm or more, and the total content of metal impurities may be 5 mg/LR or less (preferably 4 mg/LR or less, more preferably 3 mg/LR or less).

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 One

(1) step: ion exchange resin and warmed contacting the mineral solution

200 ml of H-type cation exchange resin (TRILITE MC-08HUP, Samyang Corporation) was put into a 1 L reactor made of Teflon, and 2.5 times the volume of hydrochloric acid aqueous solution (3 wt%) was added with respect to the volume of the cation exchange resin. Then, after raising the temperature in the reactor to 35 ℃, stirred while maintaining the temperature increase for 3 hours. After that, the aqueous hydrochloric acid solution was drained, and in order to adjust the pH of the cation exchange resin, 2.5 times the volume of ultrapure water with respect to the volume of the cation exchange resin was put into the reactor, stirred for 30 minutes, and then the ultrapure water was drained (Drain) process was repeated 3 times.

(2) step: washing the ion exchange resin using ultrapure water

After charging 100 ml of the cation exchange resin obtained in step (1) in a column (L 500 mm XD 20 mm), using ultrapure water, SV = 20 hr ^-1 (volume ratio of the fluid passed based on the volume of the ion exchange resin per unit time) ), the cation exchange resin was washed by passing water in a downward flow for 20 hours. At this time, the total organic carbon (TOC) of the ultrapure water was 1 ppb or less, and the specific resistance was 18.2 MΩ·cm or more.

Specific resistance, total organic carbon (TOC) and metal impurity content of the obtained cation exchange resin were measured, and the results are shown in Table 1 below.

Example 2

Except for changing the temperature increase temperature in step (1) of Example 1 from 35 ° C to 30 ° C, it was carried out in the same manner as in steps (1) and (2) of Example 1, to obtain a cation exchange resin did Specific resistance, total organic carbon (TOC) and metal impurity content of the obtained cation exchange resin were measured, and the results are shown in Table 1 below.

Example 3

Except for changing the temperature rise temperature of step (1) of Example 1 from 35 ° C. to 40 ° C., it was carried out in the same manner as in steps (1) and (2) of Example 1, to obtain a cation exchange resin did Specific resistance, total organic carbon (TOC) and metal impurity content of the obtained cation exchange resin were measured, and the results are shown in Table 1 below.

comparative example One

Specific resistance, total organic carbon (TOC) and metal impurity content of H-type cation exchange resin (TRILITE MC-08HUP, Samyang Corporation), in which steps (1) and (2) of Example 1 were not carried out, were measured. , the results are shown in Table 1 below.

comparative example 2

A cation exchange resin was obtained in the same manner as in Example 1, except that step (1) of Example 1 was not performed. Specific resistance, total organic carbon (TOC) and metal impurity content of the obtained cation exchange resin were measured, and the results are shown in Table 1 below.

comparative example 3

Except for changing the temperature rise temperature of step (1) of Example 1 from 35 ° C. to 28 ° C., it was carried out in the same manner as in steps (1) and (2) of Example 1, to obtain a cation exchange resin did Specific resistance, total organic carbon (TOC) and metal impurity content of the obtained cation exchange resin were measured, and the results are shown in Table 1 below.

comparative example 4

Except that the temperature in the reactor of step (1) of Example 1 was not raised and maintained at room temperature (25±2° C.), it was carried out in the same manner as steps (1) and (2) of Example 1 Thus, a cation exchange resin was obtained. Specific resistance, total organic carbon (TOC) and metal impurity content of the obtained cation exchange resin were measured, and the results are shown in Table 1 below.

<Method of measuring physical properties>

resistivity and gun organic carbon ( TOC ) How to measure

A column (L 500 mm XD 20 mm) was charged with the cation exchange resins obtained in Examples 1 to 3 and Comparative Examples 1 to 4, and ultrapure water having a total organic carbon (TOC) of 0.5 to 1 μg/L (ppb) was discharged downward. The flow was SV=30 hr ^-1 for 3 hours, and the specific resistance (㏁·cm) and total organic carbon (TOC) (ppb) of treated ultrapure water flowing out from the column were measured.

cation ion exchange How to measure the content of metallic impurities in resins

Using high-purity analytical hydrochloric acid (with a metal impurity content of 1 mg/L or less) from the cation exchange resins obtained in Examples 1 to 3 and Comparative Examples 1 to 4 using an uncontaminated Teflon glass, cations were used Metal impurities in the exchange resin were eluted, and the eluent was analyzed using ICP-MS. The metal ion content per unit amount of resin was calculated from the analysis result value.

[Table 1]

As shown in Table 1, in the case of Examples 1 to 3 according to the present invention, the inside of the ion exchange resin expands as the temperature is raised to 30° C. or higher, and even metal impurities present in the cross-linking can be effectively removed. It can be seen that the total impurity content was very low, and accordingly, the resistivity value was 16.3 ㏁·cm or more, and the total organic carbon output (ΔTOC) was very low at 4.2 ppb or less.

However, in the case of a commercially available ion exchange resin (Comparative Example 1), the total content of metal impurities was very high, so the resistivity value was low, the total organic carbon outflow (ΔTOC) was also very high, and only ultrapure water washing treatment was performed for the commercially available ion exchange resin. (Comparative Example 2), the total content of metal impurities was very high, and the specific resistance value was lowered, the total organic carbon outflow (ΔTOC) was also relatively high, and when a mineral acid solution at 28 ° C was used (Comparative Example 3) When a mineral acid solution at room temperature was used (Comparative Example 4), the total content of metal impurities was relatively high, so it was not suitable for use in the production of ultrapure water for semiconductors, the resistivity value was lowered, and the total organic carbon output (ΔTOC) was also It can be seen that it was relatively high.

Claims (7)

(1) contacting the cation exchange resin with a mineral acid solution at 30°C to 40°C; and
(2) washing the cation exchange resin obtained in step (1) with ultrapure water;
The total content of metal impurities in the washed cation exchange resin is 3 mg/LR or less, the total organic carbon (TOC) elution amount is 4.2 ppb or less, and the specific resistance is 16 MΩ cm or more,
The mineral acid solution is an aqueous hydrochloric acid solution having a concentration of 1 to 3% by weight,
The ultrapure water of step (2) has a total organic carbon (TOC) of 1 ppb or less and a specific resistance of 18.2 MΩ cm or more,
The washing in step (2) is performed by passing the ultrapure water through the cation exchange resin in a downflow for 15 to 20 hours at a flow rate of ^{SV=20 hr -1} to 30 hr ^-1,
A method for producing a cation exchange resin with reduced metal impurity content. delete delete delete delete delete delete