Method for regenerating an electrodeionization system and method for purifying hydrogen peroxide using the same

Abstract

A regeneration method is provided that can improve the stability and performance of an electrodeionization system. The present invention includes the steps of interrupting the operation of an electrodeionization system used for purifying hydrogen peroxide, performing electrical regeneration while supplying ultrapure water to the electrodeionization system, and restarting the electrodeionization system to purify hydrogen peroxide. 2 ~100A / m 2 This is carried out at a current density of .

Description

[Technical Field]

[0001] The present invention relates to a method for regenerating an electrodeionization system and a method for purifying hydrogen peroxide using the same, and more particularly to a method for regenerating an electrodeionization system using electrical regeneration of ultrapure water. [Background technology]

[0002] Hydrogen peroxide has strong oxidizing power and its decomposition products are harmless, so it is used as an oxidizing agent, a bleaching agent for silk thread and wool, and a catalyst for vinyl polymerization in the plastics industry. In addition to the above uses, hydrogen peroxide is also used for cleaning display wafers and semiconductor wafers.

[0003] In the information age, the field of displays that visually represent electrical information signals has been rapidly developing, and accordingly, various display devices with excellent performance such as thinness, light weight, and low power consumption have been developed.

[0004] Typically, an organic light emitting diode display device involves deposition and patterning processes of various materials on a substrate, and a conductive member such as a metal mask may be used in the deposition and patterning processes. Because the display substrate may become contaminated with various materials during the deposition and patterning processes, a cleaning process is required for the display substrate. A typical wet cleaning method for a display substrate is a chemical wet method using hydrogen peroxide.

[0005] Semiconductor wafer cleaning techniques can be divided into wet cleaning and dry cleaning. The cleaning process is similar to the etching process in that it removes materials from the semiconductor wafer surface, but differs in that it selectively removes impurities from the semiconductor wafer surface. A representative wet cleaning method is a chemical wet method using hydrogen peroxide. Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to provide a regeneration method that can improve the stability and performance of an electrodeionization system. Another object of the present invention is to provide a method for purifying hydrogen peroxide that can produce highly pure hydrogen peroxide. [Means for solving the problem]

[0007] A method for regenerating an electrodeionization system according to the present invention may include the steps of: interrupting the operation of an electrodeionization system used for purifying hydrogen peroxide; performing electrical regeneration while supplying ultrapure water to the electrodeionization system; and restarting the electrodeionization system to perform hydrogen peroxide purification. The electrical regeneration may be performed at a current of 30 A / m 2 ~100A / m 2 This can be accomplished at a current density of .

[0008] According to another aspect of the present invention, a method for purifying hydrogen peroxide may include purifying a crude hydrogen peroxide product using the adsorption resin of the primary purification system, and purifying the primarily purified hydrogen peroxide solution using a secondary purification system. The secondary purification system may include an electrodeionization system, and the electrodeionization system may be regenerated by the electrical regeneration method. A method for manufacturing an electronic device according to another aspect of the present invention may include performing a cleaning process on a substrate using hydrogen peroxide purified according to a method for purifying hydrogen peroxide. [Effects of the Invention]

[0009] The regeneration method for an electrodeionization system according to the present invention can effectively remove ions and organic carbon from the ion exchange resin, thereby preventing the generation of bubbles due to the addition of hydrogen peroxide when restarting the electrodeionization system, reducing the resistance of the electrodeionization system, and quickly restoring its performance. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating a hydrogen peroxide purification system according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a schematic diagram illustrating an electrodeionization system of the hydrogen peroxide purification system of FIG. 1. [Figure 3] 1 is a flowchart illustrating an electrical regeneration process of an electrodeionization system according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram of an electrodeionization system for illustrating the electrical regeneration process of FIG. 3. [Figure 5] 1 is a schematic diagram illustrating a hydrogen peroxide purification system according to an embodiment of the present invention. FIG. [Figure 6] 1 is a schematic diagram illustrating a substrate cleaning process using purified hydrogen peroxide according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0011] In order to fully understand the configuration and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be embodied in various forms and can be modified in various ways. However, the description of the present embodiments is provided to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art to which the present invention pertains.

[0012] In this specification, when a certain component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component can be interposed therebetween. Also, in the drawings, the thickness of the components is exaggerated for the sake of efficient explanation of the technical content. Parts designated with the same reference numerals throughout the specification refer to the same components.

[0013] In various embodiments of the present specification, terms such as first, second, and third are used to describe various components, but these components should not be limited by such terms. These terms are merely used to distinguish certain components from other components. The embodiments described and illustrated herein also include their complementary embodiments.

[0014] The terms used in this specification are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular form includes the plural form unless otherwise specified in the text. The terms 'comprises' and / or 'comprising' used in this specification do not exclude the presence or addition of one or more other components in the secondary battery having the referenced configuration.

[0015] Fig. 1 is a schematic diagram illustrating a hydrogen peroxide purification system according to an embodiment of the present invention, and Fig. 2 is a schematic diagram illustrating an electrodeionization system of the hydrogen peroxide purification system of Fig. 1.

[0016] 1 and 2, the hydrogen peroxide purification system may include a primary purification system PFS1 and a secondary purification system PFS2. The crude hydrogen peroxide product R is purified sequentially through the primary purification system PFS1 and the secondary purification system PFS2, and finally, purified hydrogen peroxide P can be obtained from the crude hydrogen peroxide product R.

[0017] The crude hydrogen peroxide R can be produced by the alkylanthraquinone process. The crude hydrogen peroxide R can be a product synthesized by the alkylanthraquinone hydrogenation-oxygenation reaction. The crude hydrogen peroxide R can be a product of the alkylanthraquinone process that has not undergone a purification step such as distillation.

[0018] Specifically, hydrogen is added to alkylanthraquinone to produce hydroquinone, which is then reacted with oxygen in the air to be reduced to anthraquinone, producing hydrogen peroxide. Crude hydrogen peroxide can be obtained by adding water to the oxidation products, anthraquinone and hydrogen peroxide, and extracting them.

[0019] The crude hydrogen peroxide product R produced by the alkylanthraquinone process contains cationic impurities (or metal impurities) such as Al, Ni, and Cr at concentrations of 100 ppb or more, PO4 at concentrations of 100 ppb or more, and 3- , SO4 2- , NO3 - , and Cl - and TOC (total organic carbon) having a concentration of 100 ppm or more.

[0020] The crude hydrogen peroxide product R may be input into the primary purification system PFS1. The primary purification system PFS1 according to one embodiment of the present invention may be a resin system.

[0021] The resin system according to the present invention may include an adsorption resin made of a porous polymer. The resin system can remove organic carbon from the crude hydrogen peroxide product R through an adsorption filter filled with the adsorption resin. The adsorption resin according to an embodiment of the present invention can remove not only organic carbon but also cations from the crude hydrogen peroxide product R.

[0022] The adsorption resin according to an embodiment of the present invention may include porous polymer particles. The specific surface area of ​​the adsorption resin is 300 m 2 / g~1,000m 2 / g. More specifically, the specific surface area of ​​the adsorption resin can be 300 m 2 / g~800m 2 / g.

[0023] The average particle size (or diameter) of the adsorbent resin may be 10 Å to 200 Å. More specifically, the average particle size of the adsorbent resin may be 40 Å to 100 Å. The particle volume of the adsorbent resin may be 0.5 mL / g to 2 mL / g. The average particle diameter of the adsorbent resin may be 0.3 mm to 2 mm.

[0024] The adsorption resin according to the present invention may be a non-polar (or neutral) resin that does not carry an electric charge. In one embodiment of the present invention, the adsorption resin may include a hydrophobic polymer. The polymer of the adsorption resin may have a hydrophobic group. For example, the hydrophobic group may include an alkyl group having 1 to 20 carbon atoms. The adsorption resin according to the present invention may be a hydrophobic adsorption resin that does not have an ion exchange group.

[0025] The adsorption resin polymer may include a polyaromatic compound. More specifically, the adsorption resin polymer may include an aromatic polymer having a hydrophobic group attached thereto. For example, the adsorption resin polymer may include at least one selected from the group consisting of a styrene / divinylbenzene copolymer, a styrene / trivinylbenzene copolymer, and a vinyltoluene / divinylbenzene copolymer. Preferably, a hydrophobic group may be attached to the copolymer.

[0026] The adsorption resin according to the present invention may be a non-polar resin that does not carry an electric charge. In one embodiment of the present invention, ion exchange resins having cation / anion functional groups may be excluded from the adsorption resin according to the present invention. The adsorption resin according to the present invention described above can adsorb and remove not only organic carbon but also ions in the crude hydrogen peroxide product R.

[0027] The primary purification system PFS1 removes some of the impurities in the crude hydrogen peroxide product R, yielding a primarily purified hydrogen peroxide solution PS. The adsorption resin in the primary purification system PFS1 reduces the TOC concentration in the primarily purified hydrogen peroxide solution PS to 100 ppm or less. The adsorption resin in the primary purification system PFS1 reduces the ion concentration in the primarily purified hydrogen peroxide solution PS.

[0028] In another embodiment of the present invention, the adsorption resin in the primary purification system PFS1 may include not only a neutral resin but also an ionic resin. Again, the adsorption resin of the present invention may be a mixture of a neutral resin and an ionic resin. The ionic resin allows for more effective removal of ions in the primary purification system PFS1.

[0029] The cations in the crude hydrogen peroxide product R are adsorbed by the adsorption resin of the primary purification system PFS1, so that the concentration of cations in the primary purified hydrogen peroxide solution PS can be lower than the concentration of cations in the crude hydrogen peroxide product R.

[0030] The purified hydrogen peroxide solution PS may be input into a secondary purification system PFS2. The secondary purification system PFS2 may include an electrodeionization system EDI. The electrodeionization process may be performed on the hydrogen peroxide solution PS using the electrodeionization system EDI.

[0031] Referring again to FIG. 2, the electrodeionization system EDI may include a first electrode ELa, a second electrode ELc, a first concentrating chamber (CC1), a second concentrating chamber CC2, and a dilute chamber (DC) between the first and second concentrating chambers CC1 and CC2. The first and second concentrating chambers CC1 and CC2 and the dilute chamber DC may be interposed between the first and second electrodes ELa and ELc. For example, the first electrode ELa may be an anode, and the second electrode ELc may be a cathode.

[0032] Anion exchange membranes EMa and cation exchange membranes EMc may be alternately arranged between the first and second electrodes ELa and ELc. For example, an anion exchange membrane EMa may be interposed between the first concentration compartment CC1 and the dilution compartment DC, and between the second concentration compartment CC2 and the second electrode ELc. A cation exchange membrane EMc may be interposed between the second concentration compartment CC2 and the dilution compartment DC, and between the first concentration compartment CC1 and the first electrode ELa. The anion exchange membrane EMa is permeable to anions but not to cations. The cation exchange membrane EMc is permeable to cations but not to anions.

[0033] An ion exchange resin ER may be provided in the dilution compartment DC. In one embodiment of the present invention, an ion exchange resin ER may also be provided in the first concentration compartment CC1 and the second concentration compartment CC2. In particular, if an ion exchange resin ER is provided in the first concentration compartment CC1 and the second concentration compartment CC2, the efficiency of hydrogen peroxide purification may be further improved. The ion exchange resin ER may include an anion exchange resin ERa and a cation exchange resin ERc. The anion exchange resin ERa can adsorb anions and transfer them to the anion exchange membrane EMa. The cation exchange resin ERc can adsorb cations and transfer them to the cation exchange membrane EMC. For example, the ion exchange resin ER can prevent the resistance of the hydrogen peroxide solution PS from increasing even if the concentration of ions in the hydrogen peroxide solution PS decreases.

[0034] A hydrogen peroxide solution PS and water can be introduced into the inlet IN of the electrodeionization system EDI. The water can be purified water with low electrical conductivity. The hydrogen peroxide concentration of the introduced hydrogen peroxide solution PS can be 1 wt% to 70 wt%.

[0035] The hydrogen peroxide solution PS may be introduced into the dilution chamber DC, and the water may be introduced into the first and second concentration chambers CC1 and CC2. The hydrogen peroxide concentrations in the first concentrate WF1 introduced into the first concentration chamber CC1 and the second concentrate WF2 introduced into the second concentration chamber CC2 may be 1 wt% or less.

[0036] A DC power supply is applied between the first and second electrodes ELa and ELc, causing a current to flow from the first electrode ELa to the second electrode ELc. Cations (e.g., metal impurities) in the hydrogen peroxide solution PS in the dilution chamber DC can pass through the cation exchange membrane EMa due to electrostatic attraction generated by the DC power supply and migrate to the second concentrate WF2 in the second concentration chamber CC2. Anions (e.g., anion impurities) in the hydrogen peroxide solution PS in the dilution chamber DC can pass through the anion exchange membrane EMa due to electrostatic attraction generated by the DC power supply and migrate to the first concentrate WF1 in the first concentration chamber CC1.

[0037] The concentration of ions in the hydrogen peroxide solution PS decreases from the inlet (IN) to the outlet (OUT) of the dilution chamber DC. In other words, the concentration of impurities in the hydrogen peroxide solution PS decreases from the inlet (IN) to the outlet (OUT) of the dilution chamber DC. Purified hydrogen peroxide P can be discharged through the outlet (OUT) of the dilution chamber DC.

[0038] The first and second concentrates WF1 and WF2 may be discharged through the outlets OUT of the first and second concentration chambers CC1 and CC2. The discharged first and second concentrates WF1 and WF2 may contain concentrated impurities transferred from the hydrogen peroxide solution PS. For example, the discharged first and second concentrates WF1 and WF2 may be discarded. For another example, the first and second concentrates WF1 and WF2 may be filtered and then reintroduced into the inlet IN of the electrodeionization system EDI. That is, the first and second concentrates WF1 and WF2 may be circulated within the electrodeionization system EDI.

[0039] Because the ion concentration of the hydrogen peroxide solution PS decreases from the inlet (IN) to the outlet (OUT) of the dilution chamber DC, the resistance of the hydrogen peroxide solution PS may increase in a region of the dilution chamber DC adjacent to the outlet (OUT). This may result in a voltage drop in the region of the dilution chamber DC, causing water decomposition and / or decomposition of hydrogen peroxide. Hydrogen ions and hydroxide ions may be generated by the water decomposition and / or decomposition of hydrogen peroxide, and the generated hydrogen ions and hydroxide ions may regenerate the ion exchange resin ER. Therefore, the electrodeionization system EDI according to the present invention may not require a separate process for regenerating the ion exchange resin ER.

[0040] The hydrogen peroxide purification system according to an embodiment of the present invention can produce high-purity hydrogen peroxide at a high yield by using an electrodeionization system EDI as the secondary hydrogen peroxide purification system PFS2. Furthermore, the electrodeionization system EDI can be operated at a relatively high flow rate, for example, 0.1 to 10 m3 / hr per electrodeionization stack. The production volume can be adjusted according to the system design (stack area, number of cells, etc.), ultimately resulting in a large volume of high-purity hydrogen peroxide.

[0041] It was confirmed that when the stability of the hydrogen peroxide solution PS introduced into the electrodeionization system EDI is lower than the standard value, the purification performance and stability of the electrodeionization system EDI decrease rapidly depending on the start-up time of the electrodeionization system EDI. In addition, it was confirmed that when the stability of the hydrogen peroxide solution PS is lower than the standard value, the removal rate of ions and organic carbon decreases rapidly depending on the start-up time of the electrodeionization system EDI.

[0042] The stability can be measured using the hydrogen peroxide stability measurement method (standard number: KSM1112) specified in the National Standards Certification Integrated Information System (KS Standard). According to an embodiment of the present invention, the standard value for stability may be 90%. More specifically, the standard value may be 95%. If the stability of the hydrogen peroxide solution PS is less than 90%, the economic performance and durability of the electrodeionization system EDI, depending on the startup time, may be significantly reduced. On the other hand, if the stability of the hydrogen peroxide solution PS is greater than 90%, the impurity removal rate of the electrodeionization system EDI, depending on the startup time, may be stably maintained, and durability may be improved.

[0043] According to an embodiment of the present invention, the adsorption resin of the primary purification system PFS1 can remove not only organic carbon but also ions (e.g., cations) from the crude hydrogen peroxide product R. Therefore, the stability of the hydrogen peroxide solution PS input to the electrodeionization system EDI can be improved. When the stability of the hydrogen peroxide solution PS is equal to or greater than the reference value, the purification performance and stability depending on the start-up time of the electrodeionization system EDI can be maintained well, and the removal rate of impurities (e.g., ions and organic carbon) can also be maintained well.

[0044] According to an embodiment of the present invention, both organic carbon and cations in the crude hydrogen peroxide product R can be removed using only the adsorption resin process of the primary purification system PFS1. As a comparative example of the present invention, if another purification system (e.g., an ion exchange resin system or a reverse osmosis system) is additionally used before inputting the hydrogen peroxide into the electrodeionization system EDI, the economic efficiency of the hydrogen peroxide purification process can be significantly reduced.

[0045] In another comparative example of the present invention, if the adsorption resin process in the primary purification system PFS1 is omitted and the crude hydrogen peroxide product R is directly introduced into the electrodeionization system EDI, the performance and stability of the electrodeionization system EDI may be significantly reduced.

[0046] The present invention can improve the performance and stability of the electrodeionization system EDI with only a simple pretreatment process (a primary purification system PFS1, which is an adsorption resin process).

[0047] 3 is a flow chart illustrating an electrical regeneration process of an electrodeionization system according to an embodiment of the present invention, and FIG. 4 is a schematic diagram of an electrodeionization system illustrating the electrical regeneration process of FIG.

[0048] 3, the operation of the electrodeionization system EDI may be interrupted (S100). For example, the operation of the electrodeionization system EDI may be interrupted to replace a module of the electrodeionization system EDI or for maintenance of the electrodeionization system EDI. The operation of the electrodeionization system EDI may also be interrupted for maintenance of the primary purification system PFS1.

[0049] In the case of an electrodeionization system EDI used in a hydrogen peroxide purification process, a regeneration process may be performed on the electrodeionization system EDI after interrupting operation and before restarting it. In particular, in order to improve the efficiency of hydrogen peroxide purification, it may be desirable to always perform a regeneration process before restarting the electrodeionization system EDI.

[0050] Referring to FIG. 4, regenerating the electrodeionization system EDI may include introducing ultrapure water (e.g., deionized water) into the first and second concentration compartments CC1, CC2 and the dilution compartment DC to clean the inside of the electrodeionization system EDI.

[0051] Specifically, first input water IW1 can be input into first concentration chamber CC1 and output as first outlet water OW1. Second input water IW2 can be input into second concentration chamber CC2 and output as second outlet water OW2. Third input water IW3 can be input into dilution chamber DC and output as third outlet water OW3. Each of the first input water IW1, second input water IW2, and third input water IW3 can be ultrapure water (e.g., deionized water).

[0052] On the other hand, there is a method of simply feeding the first to third water inputs IW1 to IW3 into the electrodeionization system EDI to regenerate the electrodeionization system EDI. While this method is appropriate for electrodeionization systems EDI used to purify water, it was found to be inappropriate for the electrodeionization system EDI used to purify hydrogen peroxide according to the present invention. It was also found that simply using only the first to third water inputs IW1 to IW3 to regenerate the electrodeionization system EDI reduces stability when the electrodeionization system EDI is restarted, and it takes a long time for performance to recover.

[0053] Meanwhile, according to an embodiment of the present invention, in addition to supplying the first to third input waters IW1 to IW3, electrical regeneration is also performed by applying current to the electrodeionization system EDI, thereby improving the stability of the electrodeionization system EDI and enabling its performance to be quickly restored when the equipment is restarted.

[0054] 4, the electrical regeneration method (S200) of the electrodeionization system EDI according to the present invention may apply a voltage to the first electrode ELa and the second electrode ELc while simultaneously introducing the first to third input waters IW1 to IW3 into the first concentrating compartment CC1, the second concentrating compartment CC2, and the diluting compartment DC, respectively. Therefore, a current DC may flow from the first electrode ELa to the second electrode ELc. The current DC may be a direct current.

[0055] In one embodiment of the present invention, the current DC during electrical regeneration may be equal to or greater than the current flowing from the first electrode ELa to the second electrode ELc during hydrogen peroxide purification in FIG. 2. The magnitude of the current DC in the present invention may vary depending on the size of the electrodeionization system EDI. The current density during electrical regeneration in the present invention is 10 A / m 2 ~100A / m 2 More specifically, the current density during electrical regeneration is 30 A / m 2 ~100A / m 2 It could be. If the current density is 30A / m 2 If the current density is lower than 100 A / m, the ion resin regeneration may not be sufficient. 2 If it is larger, problems such as side reactions and degradation of the materials of the electrodeionization system EDI may occur.

[0056] The electrical regeneration may be performed for 1 hour to 24 hours, more specifically, 1 hour to 3 hours. The flow rates of the first to third input waters IW1 to IW3 may be appropriately selected by the user according to the installation guide of the electrodeionization system EDI. For example, the flow rates of the first to third input waters IW1 to IW3 may be substantially the same as the flow rates of the first concentrate WF1, the second concentrate WF2, and the hydrogen peroxide solution PS in FIG. 2, respectively. In one embodiment of the present invention, the flow rates of the first input water IW1 and the second input water IW2 may be the same. The flow rate of the first input water IW1 may be smaller than the flow rate of the third input water IW3.

[0057] The ion exchange resin ER in the electrodeionization system EDI according to the present invention can be regenerated through electrical regeneration. Impurities in the ion exchange resin ER of the electrodeionization system EDI can be effectively removed through electrical regeneration. In particular, ions and organic carbon in the ion exchange resin ER can be effectively removed through electrical regeneration.

[0058] 3, after electrical regeneration of the electrodeionization system EDI, the conductivity of the third effluent OW3 discharged from the dilution chamber DC of the electrodeionization system EDI can be measured (S300). By measuring the conductivity of the third effluent OW3, it can be determined whether the organic carbon and ions (e.g., cations and anions) in the ion exchange resin ER have been removed to a level that satisfies a reference value (S400).

[0059] If the conductivity of the third effluent OW3 is equal to or greater than the reference value, it can be determined that the ion exchange resin ER has not been sufficiently regenerated. In this case, electrical regeneration (S200) of the electrodeionization system EDI can be performed again to ensure the stability of the electrodeionization system EDI.

[0060] In one embodiment of the present invention, the ion exchange resin ER can be reused through electrical regeneration (S200), but may also be replaced at predetermined intervals (for example, every six months).

[0061] If the conductivity of the third effluent OW3 is less than the reference value, it can be determined that the ion exchange resin ER has been regenerated to the desired extent, which means that the stability of the electrodeionization system EDI has been ensured, and the electrodeionization system EDI can be restarted for hydrogen peroxide purification (S500).

[0062] The reference value of the conductivity of the third effluent OW3 may be defined based on the condition that stable operation is possible when the electrodeionization system EDI is restarted. The reference value of the conductivity may be defined as the condition under which the decomposition reaction of hydrogen peroxide within the electrodeionization system EDI is minimized and channeling problems are eliminated when the electrodeionization system EDI is restarted. The reference value of the conductivity may be defined as a value between 5.0 μs / m and 20.0 μs / m. More specifically, the reference value of the conductivity may be defined as a value between 5.0 μs / m and 10.0 μs / m. For example, if the reference value of the conductivity is set to 20.0 μs / m, it can be determined that the ion exchange resin ER has been regenerated to the desired extent when the conductivity of the third effluent OW3 is measured to be less than 20.0 μs / m.

[0063] Experimental Example 1 The electrodeionization system was shut down, and the electrical regeneration of the electrodeionization system was carried out as described with reference to Figures 3 and 4. Specifically, ultrapure water (deionized water) was introduced into the concentration and dilution compartments of the electrodeionization system, and a current of 77 A / m 2 A current of 0.01% was applied for 2 hours and 30 minutes. After that, the conductivity of the effluent discharged from the dilution chamber was measured at 6.3 μs / m. After electrical regeneration of the electrodeionization system, it was restarted and the removal rate of cations in hydrogen peroxide was measured (Example 1).

[0064] The electrodeionization system was shut down and regenerated by cleaning it with ultrapure water. Specifically, cleaning was performed by supplying only ultrapure water to the concentration and dilution compartments without any additional current to the electrodeionization system. After cleaning and regeneration, the conductivity of the effluent discharged from the dilution compartment was measured at 13 μs / m. After cleaning and regeneration, the electrodeionization system was restarted and the removal rate of cations in hydrogen peroxide was measured (Comparative Example 1). The results of the first example and the first comparative example are shown in Table 1 below.

[0065] [Table 1]

[0066] In Comparative Example 1, we observed a significant decrease in the removal rate of cations such as Al, K, Ca, Fe, Ni, and Zn on the first day after restarting the electrodeionization system. This was due to the decomposition of hydrogen peroxide by ions adsorbed on the EDI ion exchange resin, resulting in performance degradation such as the generation of bubbles. Although the cation removal rate recovered to some extent on the sixth day after restart, it took more than a week for performance to recover to the level before operation was interrupted. The longer the EDI is operated, the longer the recovery time may take. In contrast, in Example 1, we observed that the removal rate of cations such as Al, K, Ca, Fe, Ni, and Zn did not decrease significantly on the first day after restarting the electrodeionization system compared to before system interruption. Furthermore, we observed that the performance of the electrodeionization system was fully restored on the fourth day after restarting.

[0067] That is, the ultrapure water electrical regeneration of the electrodeionization system according to the present invention can prevent the generation of bubbles due to the addition of hydrogen peroxide when restarting the electrodeionization system, and can quickly restore the performance of the electrodeionization system.

[0068] Experimental Example 2 Hydrogen peroxide was purified using an electrodeionization system, and the cation and anion concentrations of the purified hydrogen peroxide discharged from the dilution compartment were measured. The electrodeionization system was then shut down, and the electrical regeneration of the electrodeionization system was performed as described with reference to Figures 3 and 4. Specifically, ultrapure water (deionized water) was introduced into the concentration and dilution compartments of the electrodeionization system, and a current of 73 A / m was applied. 2 A current of 0.01 V was applied for 3 hours. After the electrodeionization system was restarted after electrical regeneration, the concentrations of cations and anions in the purified hydrogen peroxide discharged from the dilution compartment were measured (Example 2).

[0069] Hydrogen peroxide was purified using an electrodeionization system, and the cation and anion concentrations of the purified hydrogen peroxide discharged from the dilution compartment were measured. The electrodeionization system was then shut down, and the electrical regeneration of the electrodeionization system was performed as described with reference to Figures 3 and 4. Specifically, ultrapure water (deionized water) was introduced into the concentration and dilution compartments of the electrodeionization system, and a current of 20 A / m was applied. 2 A current of 0.01 V was applied for 3 hours. After the electrodeionization system was regenerated, it was restarted and the concentrations of cations and anions in the purified hydrogen peroxide discharged from the dilution compartment were measured (Comparative Example 2). The results of the second comparative example and the second example are shown in Table 2 below.

[0070] [Table 2]

[0071] In the second comparative example, it was confirmed that the concentrations of cations (Na, K, Cr, Ni, and Zn) in the purified hydrogen peroxide were similar or even increased when comparing before and after electrical regeneration. 2 When electrical regeneration was performed on the electrodeionization system at a lower current density, it was confirmed that the concentrations of cations and anions remained similar to those before regeneration or slightly increased. This may be because the current density in the electrical regeneration performed in Comparative Example 2 was insufficient for the regeneration of the ion resin. In Example 2, a comparison of the concentrations of cations (Na, K, Cr, Ni, and Zn) in the purified hydrogen peroxide before and after electrical regeneration confirmed a significant decrease. That is, at 30 A / m 2 ~100A / m 2 When electrical regeneration was performed on the electrodeionization system at a current density of 100 kJ / cm², it was confirmed that the concentrations of cations and anions in the hydrogen peroxide solution after regeneration were similar to or significantly decreased compared to those before regeneration. This confirmed that electrical regeneration was performed satisfactorily at the current density of Example 2.

[0072] Figure 5 is a schematic diagram illustrating a hydrogen peroxide purification system according to an embodiment of the present invention. Referring to Figure 5, the hydrogen peroxide purification system may further include a heat exchanger HE disposed between the primary purification system PFS1 and the secondary purification system PFS2. The primarily purified hydrogen peroxide solution PS passes through the heat exchanger HE, whereby its temperature can be adjusted. The heat exchanger HE can adjust the temperature of the hydrogen peroxide solution PS to between -20°C and 20°C. Again, the hydrogen peroxide solution PS having a temperature between -20°C and 20°C can be input into the electrodeionization system EDI, which is the secondary purification system PFS2.

[0073] Hydrogen peroxide is a strong oxidizing agent and can oxidize and age the ion exchange media it comes into contact with in the dilution chamber DC of the electrodeionization system EDI. Therefore, the oxygen generated by the decomposition of hydrogen peroxide as a side reaction in the dilution chamber DC can increase the pressure within the electrodeionization system EDI. The higher the temperature of the hydrogen peroxide, the more rapidly the amount of oxygen produced. If excessive oxygen is produced, the pressure within the electrodeionization system EDI increases excessively, damaging the electrodeionization system EDI and reducing the efficiency of the purification process.

[0074] According to this embodiment, the heat exchanger HE appropriately controls the temperature of the hydrogen peroxide solution PS fed into the electrodeionization system EDI, thereby preventing excessive oxygen generation. The heat exchanger HE further improves the stability of the hydrogen peroxide solution PS of the present invention. As a result, damage to the electrodeionization system EDI can be prevented and the purification efficiency of hydrogen peroxide can be increased.

[0075] High-purity hydrogen peroxide can be obtained through the method for purifying hydrogen peroxide according to the above-described embodiment of the present invention. Figure 6 is a schematic diagram illustrating a substrate cleaning process using hydrogen peroxide purified according to the embodiment of the present invention.

[0076] 6, the method for manufacturing an electronic device may include a cleaning process of a substrate SUB. The substrate SUB according to an embodiment of the present invention may include a display substrate or a semiconductor substrate. Specifically, the cleaning process of the substrate SUB may include applying hydrogen peroxide P purified by the purification method of the present invention onto the substrate SUB. For example, the display substrate may include a substrate for an organic electroluminescent display device, a substrate for a micro LED display device, or an LCD substrate. The semiconductor substrate SUB may include silicon, germanium, or silicon-germanium.

[0077] If hydrogen peroxide containing impurities is used in the cleaning process, the impurities may react with materials on the substrate SUB, causing process defects. On the other hand, the purified hydrogen peroxide P according to the present invention has a very low impurity content, thereby preventing defects from occurring in the cleaning process.

[0078] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the above-described embodiments are illustrative in all respects and are not limiting. [Explanation of symbols]

[0079] CC1 1st concentration room CC2 2nd concentration chamber DC Dilution Chamber ER ion exchange resin HE heat exchanger PFS1 Primary Purification System PFS2 Secondary Purification System PS hydrogen peroxide solution SUB board WF1 1st concentrate WF2 2nd concentrate

Claims

1. interrupting operation of an electrodeionization system used to purify hydrogen peroxide; performing electrical regeneration while introducing ultrapure water into the electrodeionization system; restarting the electrodeionization system to perform hydrogen peroxide purification; The electrical regeneration is 30 A / m ２ ~100A / m ２ 2. A method for regenerating an electrodeionization system, comprising:

2. 2. The method of claim 1, wherein the electrical regeneration is performed for a period of 1 hour to 24 hours.

3. measuring the conductivity of the effluent of the electrodeionization system; restarting the electrodeionization system when the conductivity is lower than a reference value; 2. The method of claim 1, wherein the reference value is defined as a value between 5.0 μs / m and 20.0 μs / m.

4. The electrodeionization system comprises: a first electrode and a second electrode; a first concentrating compartment, a second concentrating compartment, and a diluting compartment between the first and second concentrating compartments; an ion exchange resin provided in the dilution chamber, the first concentration chamber, and the second concentration chamber; an anion exchange membrane between the first concentrating compartment and the diluting compartment; 2. The method of claim 1, further comprising a cation exchange membrane between the second concentrating compartment and the diluting compartment.

5. introducing the ultrapure water into the electrodeionization system adding a first input water to the first concentration compartment; introducing a second input water into the second concentrating compartment; 5. The method of claim 4, further comprising: introducing a third input water into the dilution chamber.

6. 5. The method of claim 4, wherein the step of performing electrical regeneration includes passing a current from the first electrode to the second electrode.

7. 5. The method of claim 4, wherein the step of performing electrical regeneration includes removing ions from the ion exchange resin.

8. purifying the crude hydrogen peroxide product using an adsorption resin in a primary purification system; and purifying the primarily purified hydrogen peroxide solution using a secondary purification system; the secondary purification system includes an electrodeionization system; 10. A method for purifying hydrogen peroxide, wherein the electrodeionization system is regenerated by the method of claim 1.

9. 9. The method for purifying hydrogen peroxide according to claim 8, wherein the adsorption resin comprises a hydrophobic aromatic polymer.

10. 9. The method for purifying hydrogen peroxide according to claim 8, wherein the adsorption resin includes a neutral resin and an ionic resin.

11. 9. The method for purifying hydrogen peroxide according to claim 8, further comprising passing the primarily purified hydrogen peroxide solution through a heat exchanger.

12. 10. A method for manufacturing an electronic device, comprising performing a cleaning process on a substrate using the purified hydrogen peroxide of claim 1.

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