A method for preparing electronic-grade hydrogen peroxide

Abstract

This invention belongs to the field of wet electronic chemicals technology, specifically relating to a method for preparing electronic-grade hydrogen peroxide. The method includes the following steps: adjusting the concentration of raw hydrogen peroxide, and then filtering it sequentially through a reverse osmosis membrane, a modified cation exchange resin, an anion exchange resin, and a mixed ion exchange resin to obtain electronic-grade hydrogen peroxide. The modified cation exchange resin used is modified based on conventional cation exchange resin through pore expansion and grafting, optimizing the spatial matching of pore structure and functional sites. This achieves passivation of metal ions, enhanced adsorption capacity, and improved oxidation resistance, as well as a deep synergistic effect of these three effects. Ultimately, it achieves the dual goals of efficient purification and stable operation of the resin in the hydrogen peroxide system. The resulting electronic-grade hydrogen peroxide can reduce the content of single impurity metal ions to below 5 ppt, meeting the requirements of SEMI G5 standards, and can be directly applied to high-end manufacturing fields such as semiconductor wafer cleaning.

Description

Technical Field

[0001] This invention belongs to the field of wet electronic chemicals technology, specifically relating to a method for preparing electronic-grade hydrogen peroxide. Background Technology

[0002] Hydrogen peroxide (H2O2, also known as hydrogen peroxide solution) is widely used due to its unique oxidizing properties. Different application areas have different technical requirements for hydrogen peroxide. Based on common applications, hydrogen peroxide can be classified into industrial grade, reagent grade, pharmaceutical grade, food grade, electronic grade, and propellant grade, among others. Electronic grade hydrogen peroxide, in particular, is in high demand due to the growing demand from the electronics industry as an important cleaning and etching agent. However, current large-scale industrial production of hydrogen peroxide mostly uses the anthraquinone process. The resulting hydrogen peroxide products have high impurity content and cannot directly meet the requirements of medical, food, semiconductor, and military applications. Therefore, a series of purification and refining processes are necessary for industrial-grade hydrogen peroxide.

[0003] Commonly used methods for hydrogen peroxide purification include distillation, adsorption, ion exchange resin method, membrane separation method, crystallization method, and supercritical fluid extraction method. Among these, ion exchange resin method and membrane separation method have become the mainstream in industrial applications due to their low energy consumption and cost, as illustrated by patents CN1919724A, CN118651823A, and CN119873753A. However, impurities such as metal cations like Fe are present. 3+ Zn 2+ Ni 2+ After being enriched on the resin, hydrogen peroxide can easily decompose through a chain reaction of "adsorption-migration-catalytic decomposition", increasing the risk of oxygen explosion in a closed environment. In order to reduce the risk of explosion, the ion exchange column needs to be continuously cooled in actual production, which greatly increases energy consumption and production costs. Summary of the Invention

[0004] To overcome the above purification difficulties, this application provides a method for preparing electronic-grade hydrogen peroxide, comprising the following steps: The concentration of the raw hydrogen peroxide is adjusted, and then filtered sequentially through a reverse osmosis membrane, a modified cation exchange resin, an anion exchange resin, and a mixed ion exchange resin to obtain electronic-grade hydrogen peroxide. The modified cation exchange resin is grafted with fullerene.

[0005] Furthermore, the fullerene loading of the modified cation exchange resin is 0.0006-0.0015 mmol / g.

[0006] Furthermore, the modified cation exchange resin is obtained by performing pretreatment, pore expansion, fullerene grafting, and posttreatment on the cation exchange resin in sequence. The cation exchange resin includes a styrene-divinylbenzene backbone and acidic active groups grafted onto the backbone.

[0007] The pretreatment is as follows: first soaking in electronic grade hydrochloric acid, then rinsing with pure water until the pH of the effluent is 3.5-4.0, and finally soaking in anhydrous ethanol.

[0008] The pore-expanding process involves immersing the resin in a pore-expanding agent, followed by a gradient temperature increase to remove the agent. The pore-expanding agent is a mixture of n-heptane and toluene, with a volume ratio of 2-4:1. The gradient temperature increase is performed under vacuum conditions, sequentially raising the temperature from room temperature to 30-35℃, 50-55℃, and 65-70℃, maintaining each temperature for at least 30 minutes after reaching the target temperature, with a heating rate ≤0.5℃ / min.

[0009] The grafted fullerene is prepared by first obtaining a fullerene pre-dispersion, then mixing it with resin, heating it to 50-60℃ under nitrogen protection, adding an initiator, and reacting for 4-8 hours. The volume ratio of the resin to the pre-dispersion is 1:2-5. The mass ratio of fullerene powder to methyl methacrylate and anhydrous ethanol in the fullerene pre-dispersion is 1:15-25:60-100. The amount of initiator used is 0.2-2% of the mass of methyl methacrylate, and the initiator is selected from azobisisobutyronitrile (AIB) or benzoyl peroxide.

[0010] The post-treatment is as follows: the resin after grafting reaction is rinsed with anhydrous ethanol and pure water, and the water washing endpoint is when the conductivity of the effluent is ≤5μS / cm.

[0011] The beneficial effects of this invention are as follows: This application achieves the dual goals of passivating metal ions, enhancing adsorption capacity, and improving oxidation resistance through spatial matching of pore structure and functional sites, ultimately achieving the dual objectives of efficient purification and stable operation of the resin in the hydrogen peroxide system.

[0012] First, fullerenes possess a conjugated spherical structure, with a large number of delocalized π electrons on their molecular surface, which can form electron trap sites. When the acidic groups of the resin adsorb Fe... 3+ Zn 2+ Ni 2+ After being exposed to catalytic heavy metal ions, the unpaired electrons of the metal ions are captured by electron traps, causing the valence state of the metal ions to stabilize and lose their catalytic activity for hydrogen peroxide decomposition, thus significantly reducing the hydrogen peroxide decomposition rate.

[0013] Secondly, traditional resins have dense pores with poor connectivity, and some acidic groups are trapped inside the resin, unable to contact metal ions. After pore expansion, the specific surface area of ​​the resin is significantly increased, the pore diameter is significantly increased, and the hidden acidic groups are fully exposed, effectively increasing the number of exchange sites. Moreover, the interconnected macroporous-mesoporous structure shortens the diffusion path of metal ions, reducing the time for ions to diffuse from the resin surface to the internal active sites, and significantly improving the adsorption rate. These improvements result in a significant increase in the removal rate of metal ions by the modified resin.

[0014] Third, fullerenes have high C-C bond energies, approximately 715 kJ / mol, and excellent oxidation resistance. When grafted onto the resin surface and pore walls, they can form an antioxidant barrier, blocking hydrogen peroxide from oxidizing and eroding the resin skeleton, thereby improving the resin's oxidation resistance and extending its service life by more than two times.

[0015] Fourth, after pore expansion, fullerenes are distributed on the inner wall of the pores, interspersed with acidic groups. Metal ions can be immediately passivated after adsorption, avoiding the chain reaction of "adsorption-migration-catalytic decomposition". At the same time, efficient adsorption and rapid removal of metal ions in the system further reduces the risk of hydrogen peroxide decomposition. The two form a positive cycle of "adsorption promotes passivation, and passivation ensures adsorption stability".

[0016] Using the modified resin of this application to purify hydrogen peroxide, the content of single metal ion impurities can be reduced to below 5ppt, meeting the requirements of SEMI G5 standard, and can be directly applied to the high-end manufacturing field of semiconductor wafer cleaning. Detailed Implementation

[0017] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. These embodiments are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention or the method of implementing the present invention. The modified solvents and raw materials used are all of electronic grade purity.

[0018] This application provides a method for preparing electronic-grade hydrogen peroxide, including the following steps: adjusting the concentration of raw material hydrogen peroxide, for example, diluting industrial hydrogen peroxide raw material with a concentration of 50%wt to a target concentration of 31%wt, and then filtering it sequentially through a reverse osmosis membrane (RO), a modified cation exchange resin, an anion exchange resin, and a mixed ion exchange resin to obtain electronic-grade hydrogen peroxide.

[0019] The reverse osmosis membrane can retain most organic matter and heavy metal ions. Commonly used models include Dow BW30-8040, Hydranautics ESPA2-8040, and Toray TM720D-400. If necessary, a microfiltration membrane can be used before the reverse osmosis membrane to remove organic impurities and large particulate impurities, such as a 0.1-0.5μm microfiltration membrane.

[0020] The modified cation exchange resin is obtained by modifying a conventional cation exchange resin, the anion exchange resin is a conventional anion exchange resin used for purifying water, and the mixed ion exchange resin is a mixture of the modified cation exchange resin and the conventional anion exchange resin. Preferably, the mixing ratio is cation resin: anion resin = 1:1.8-2.2.

[0021] The aforementioned unmodified conventional cation exchange resins are commonly used cation exchange resins for water purification on the market. Preferred resins are those with styrene-divinylbenzene as the backbone and sulfonic acid, carboxylic acid, and phosphonic acid groups as acidic groups, such as models 001×7, C-100E, Lewatit TP208, Puromet MTS9570, and SC350U.

[0022] Furthermore, the specific modification method of the above-mentioned modified cation exchange resin includes pretreatment, pore expansion, grafting fullerene, and posttreatment of the cation exchange resin in sequence. The cation exchange resin commonly used for purified water includes a styrene-divinylbenzene skeleton and acidic active groups grafted onto the skeleton. The acidic active groups are one or more of sulfonic acid groups, carboxylic acid groups, and phosphonic acid groups.

[0023] Preferably, the pretreatment is as follows: first, soaking in 3-8% hydrochloric acid for 3-6 hours to remove any possible residual metal impurities and activate acidic groups; then rinsing with pure water until the pH of the effluent is 3.5-4.0 to fully remove residual hydrochloric acid; and finally soaking in anhydrous ethanol for 1-4 hours to replace the water in the pores and improve the compatibility between the pore-forming agent and the resin.

[0024] Preferably, the pore-expanding process involves immersing the resin in a pore-expanding agent for at least 20 hours to allow the agent to fully penetrate, followed by a gradient temperature increase to remove the agent. The pore-expanding agent is a mixture of n-heptane and toluene, with a volume ratio of 2-4:1. The gradient temperature increase is performed under a vacuum of -0.05 to -0.08 MPa, sequentially raising the temperature from room temperature to 30-35°C, 50-55°C, and 65-70°C, respectively. After reaching the target temperature, the temperature is maintained at these temperatures for at least 30 minutes, for example, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, and 80 minutes. After 90 minutes of observation, and once no violent bubbling is observed in the system, proceed to the next stage. At 30-35℃, n-heptane is removed to initially establish a macroporous structure. At 50-55℃, toluene is removed to form a macroporous-mesoporous interconnected structure. At 65-70℃, residual pore-forming agent on the inner wall of the pores is removed to stabilize the pore size. Then, the system is allowed to cool naturally to room temperature. The heating rate should be ≤0.5℃ / min, such as 0.2℃ / min, 0.3℃ / min, 0.4℃ / min, or 0.5℃ / min. Controlling the slow heating rate is to prevent pore collapse.

[0025] Preferably, the grafted fullerene is prepared by: first preparing a fullerene pre-dispersion, then mixing it with resin, heating it to 50-60°C under nitrogen protection, adding an initiator, and reacting for 4-8 hours. This process involves free radical polymerization, anchoring the fullerene to the inner wall of the resin pores. The volume ratio of the resin to the pre-dispersion is 1:2-5. The mass ratio of fullerene powder to methyl methacrylate and anhydrous ethanol in the fullerene pre-dispersion is 1:15-25:60-100. Ultrasonic measures can be used to assist in the pre-dispersion to control the temperature ≤30°C. The amount of initiator is 0.2-2% of the mass of methyl methacrylate, and the initiator is selected from azobisisobutyronitrile or benzoyl peroxide.

[0026] The fullerenes used in this application are preferably nano-sized powders prepared by the gas phase method, with a particle size of 100-500 nm. This particle size is more compatible with the resin pore size. If the particle size is too small, it is easy to agglomerate and it is difficult to disperse evenly in the grafting solution. If the particle size is too large, it cannot enter the resin pores and can only adhere to the resin surface, which will reduce the passivation effect.

[0027] Preferably, the post-treatment is as follows: the resin after grafting reaction is rinsed with anhydrous ethanol and pure water, the ethanol is used to wash away methyl methacrylate and free fullerene, and the water is used to wash away residual ethanol. The water washing endpoint is when the conductivity of the effluent is ≤5μS / cm.

[0028] Preferably, the modified cation exchange resin comprises a styrene-divinylbenzene backbone and acidic active groups and fullerenes grafted onto the backbone. The acidic active groups are one or more selected from sulfonic acid groups, carboxylic acid groups, and phosphonic acid groups, with a loading of 3-8 mmol / g and a fullerene loading of 0.0006-0.0015 mmol / g. The loading method is as follows: a. The method for detecting the content of acidic active groups is as follows: Dry the resin at 105℃ to constant weight, weigh 0.5g of the constant-weight dry resin, add 50mL of 1mol / L NaCl solution, seal and shake for 24h, so that the H in the resin can be reduced. + Completely by Na + Displacement; Take 25 mL of the supernatant after the above displacement, add 2 drops of phenolphthalein indicator, and titrate with 0.1 mol / L NaOH standard solution until the solution turns pink. Record the volume V (mL) of NaOH solution consumed.

[0029] Molar loading of acidic active groups (mmol / g) = (C NaOH ×V×2)÷m 干树脂 , Among them, C NaOH The concentration of the NaOH standard solution is (mol / L), V is the volume of NaOH solution consumed (mL), 2 is the dilution factor (25mL of supernatant is taken, and 50mL of the original solution is taken), and m is the concentration of the standard NaOH solution. 干树脂 The mass (g) of the resin after constant weight is given.

[0030] The method for detecting fullerene content is as follows: Weigh 10 mg of constant-weight dry resin and place it in an alumina crucible. Under high-purity nitrogen protection, heat the resin to 900℃ at a rate of 10℃ / min. Analyze the TG curve and calculate the weight loss rate w (%) at 600–800℃. This is because 600–800℃ corresponds to the fullerene cracking and vaporization stage, while 300–500℃ corresponds to the weight loss stage of the resin skeleton and groups.

[0031] Fullerene molar loading (mmol / g) = w ÷ (M 富勒烯 (×1000), Among them, M 富勒烯 The molecular weight of fullerene is 720 g / mol.

[0032] Example 1 A method for obtaining a modified cation exchange resin.

[0033] (1) Resin pretreatment: Commercially available 001×7 type cation exchange resin was selected, soaked in 5% hydrochloric acid for 4 hours, then rinsed with pure water until the pH of the effluent was 3.6, and finally soaked in anhydrous ethanol for 2 hours.

[0034] (2) Resin pore expansion: a pore expansion agent is prepared by mixing n-heptane and toluene at a volume ratio of 3:1 and transferring it into a sealed container. The pretreated resin is immersed in the pore expansion agent for 24 hours, then the vacuum is drawn to -0.08 MPa, the temperature is increased to 32°C at 0.4°C / min and held for 40 minutes, then the temperature is increased to 50°C at 0.4°C / min and held for 90 minutes, then the temperature is increased to 68°C at 0.4°C / min and held for 30 minutes, and then the temperature is allowed to cool naturally to room temperature.

[0035] (3) Grafting fullerene: Methyl methacrylate and anhydrous ethanol are mixed at a mass ratio of 1:4, and then 5% of the mass of methyl methacrylate and 200 nm fullerene are added. The mixture is stirred and ultrasonically applied for 30 min to obtain a fullerene pre-dispersion. The mixture is then transferred to a sealed container, and the resin obtained in step (2) is added. The mixture is stirred at 60 r / min with a solid-liquid ratio of 1:3. Nitrogen gas is introduced, and the temperature is raised to 55 °C. Azobisisobutyronitrile (AIORT) is added at a mass of 1% of the mass of methyl methacrylate. The mixture is stirred at 60 r / min and reacted for 6 h. The mixture is then allowed to cool naturally to room temperature and the liquid is filtered out.

[0036] (4) Post-treatment: The grafted resin was rinsed with anhydrous ethanol for 10 min and then rinsed with pure water for 10 min. The conductivity of the effluent was 3.2 μS / cm.

[0037] Example 2 A method for obtaining a modified cation exchange resin.

[0038] (1) Resin pretreatment: Commercially available 001×7 type cation exchange resin was selected, soaked in 3% hydrochloric acid for 4 hours, then rinsed with pure water until the pH of the effluent was 3.8, and finally soaked in anhydrous ethanol for 2 hours. (2) Resin pore expansion: a pore expansion agent was prepared by mixing n-heptane and toluene at a volume ratio of 2.8:1 and transferred to a sealed container. The pretreated resin was soaked in the pore expansion agent for 30 hours. Then, the vacuum was drawn to -0.05 MPa, the temperature was increased to 30°C at 0.4°C / min and held for 60 minutes. The vacuum was increased to -0.07 MPa, the temperature was increased to 52°C at 0.5°C / min and held for 80 minutes. The temperature was then increased to 70°C at 0.4°C / min and held for 35 minutes. Then, the temperature was allowed to cool naturally to room temperature.

[0039] (3) Grafting fullerene: Methyl methacrylate and anhydrous ethanol were mixed at a mass ratio of 1:4, and then 4% of the mass of methyl methacrylate and 300 nm fullerene were added. The mixture was stirred and ultrasonically applied for 30 min to obtain a fullerene pre-dispersion. The mixture was transferred to a sealed container, and the resin obtained in step (2) was added. The mixture was stirred at 60 r / min with a solid-liquid ratio of 1:3. Nitrogen gas was introduced, and the temperature was raised to 57 °C. 0.8% of the mass of methyl methacrylate and azobisisobutyronitrile were added. The mixture was stirred at 60 r / min and reacted for 8 h. The mixture was then allowed to cool naturally to room temperature and the liquid was filtered out.

[0040] (4) Post-treatment: The grafted resin was rinsed with anhydrous ethanol for 10 min and then rinsed with pure water for 10 min. The conductivity of the effluent was 3.5 μS / cm.

[0041] Example 3 A method for obtaining a modified cation exchange resin.

[0042] (1) Resin pretreatment: Lewatit TP208 cation exchange resin was selected from the market, soaked in 5% hydrochloric acid for 4 hours, then rinsed with pure water until the pH of the effluent was 4.0, and finally soaked in anhydrous ethanol for 2 hours. (2) Resin pore expansion: a pore expansion agent was prepared by mixing n-heptane and toluene at a volume ratio of 3.4:1 and transferred to a sealed container. The pretreated resin was soaked in the pore expansion agent for 20 hours. Then, the vacuum was drawn to -0.06 MPa, the temperature was increased to 35°C at 0.4°C / min and held for 50 minutes. Then, the temperature was increased to 55°C at 0.4°C / min and held for 90 minutes. Then, the temperature was increased to 68°C at 0.3°C / min and held for 30 minutes. Then, the temperature was allowed to cool naturally to room temperature.

[0043] (3) Grafting fullerene: Methyl methacrylate and anhydrous ethanol are mixed at a mass ratio of 1:5, and then 6% of the mass of methyl methacrylate and 150nm fullerene are added. The mixture is stirred and ultrasonically applied for 30min to obtain a fullerene pre-dispersion. The mixture is then transferred to a sealed container, and the resin obtained in step (2) is added. The mixture is stirred at 40r / min with a solid-liquid ratio of 1:4. Nitrogen gas is introduced, and the temperature is raised to 52℃. Benzoyl peroxide at 1% of the mass of methyl methacrylate is added, and the mixture is stirred at 40r / min for 5h. The mixture is then allowed to cool naturally to room temperature and the liquid is filtered out.

[0044] (4) Post-treatment: The grafted resin was rinsed with anhydrous ethanol for 10 min and then rinsed with pure water for 10 min. The conductivity of the effluent was 3.9 μS / cm.

[0045] Example 4 A method for obtaining a modified cation exchange resin.

[0046] (1) Resin pretreatment: Puromet MTS9570 cation exchange resin was selected from the market. It was soaked in 5% hydrochloric acid for 3 hours, then rinsed with pure water until the pH of the effluent was 4.0, and finally soaked in anhydrous ethanol for 2 hours. (2) Resin pore expansion: a pore expansion agent is prepared by mixing n-heptane and toluene at a volume ratio of 3:1 and transferring it into a sealed container. The pretreated resin is immersed in the pore expansion agent for 24 hours. Then, the vacuum is drawn to -0.07 MPa, the temperature is increased to 31°C at 0.4°C / min and held for 60 min. Then, the temperature is increased to 52°C at 0.4°C / min and held for 90 min. Then, the temperature is increased to 68°C at 0.5°C / min and held for 30 min. Then, the temperature is allowed to cool naturally to room temperature.

[0047] (3) Grafting fullerene: Methyl methacrylate and anhydrous ethanol are mixed at a mass ratio of 1:5, and then 5% of the mass of methyl methacrylate is added to high-purity fullerene with a particle size of 120 nm. The mixture is stirred and ultrasonically applied for 30 min to obtain a fullerene pre-dispersion. The mixture is then transferred to a sealed container, and the resin obtained in step (2) is added. The mixture is stirred at 40 r / min with a solid-liquid ratio of 1:3.5. Nitrogen gas is introduced, and the temperature is raised to 54 °C. Benzoyl peroxide at a mass of 1.2% of the mass of methyl methacrylate is added, and the mixture is stirred at 40 r / min for 6 h. The mixture is then allowed to cool naturally to room temperature and the liquid is filtered out.

[0048] (4) Post-treatment: The grafted resin was rinsed with anhydrous ethanol for 10 min and then rinsed with pure water for 10 min. The conductivity of the effluent was 3.5 μS / cm.

[0049] The acidic groups and fullerene molar content of the modified resins obtained in Examples 1-4 were detected and recorded in Table 1.

[0050] Table 1. Test results of modified cation exchange resin Example 5 A method for preparing electronic-grade hydrogen peroxide, using the modified cation exchange resin obtained in Example 1, includes the following steps: S1, Dilution: Control the temperature ≤25℃, inject ultrapure water into 50%wt hydrogen peroxide, mix evenly to obtain 31.0%wt hydrogen peroxide; S2, Pretreatment: Filter with a 0.2μm microfiltration membrane to remove large particulate impurities at a pressure of 0.12 MPa; S3, Primary RO membrane filtration: Temperature control ≤15℃, using BW30-8040 type RO membrane filtration, pressure 2.7MPa; S3, Secondary RO membrane filtration: Temperature controlled ≤15℃, using BW30-8040 type RO membrane filtration, pressure 1.8MPa; S4, Filtration with modified cation exchange resin: control the temperature ≤10℃, filter with the modified cation exchange resin obtained in Example 1, pressure 0.15MPa, flow rate 6BV / h; S5, Anion exchange resin filtration: control temperature ≤10℃, use 201×7 type anion exchange resin for filtration, pressure 0.15MPa, flow rate 4.5BV / h; S6, Mixed ion exchange resin filtration: control temperature ≤10℃, use mixed ion exchange resin, wherein the volume ratio of modified 001×7 cation exchange resin to 201×7 anion exchange resin is 1:2, pressure 0.1MPa, flow rate 3BV / h.

[0051] The modified cation exchange resin has a service life of 150 hours.

[0052] Example 6 A method for preparing electronic-grade hydrogen peroxide, using the modified cation exchange resin obtained in Example 3, includes the following steps: S1, Dilution: Control the temperature ≤20℃, inject ultrapure water into 50%wt hydrogen peroxide, mix evenly to obtain 31.0%wt hydrogen peroxide; S2, Pretreatment: Filter with a 0.2μm microfiltration membrane to remove large particulate impurities at a pressure of 0.15 MPa; S3, Primary RO membrane filtration: Temperature control ≤12℃, using TM720D-400 type RO membrane filtration, pressure 2.9MPa; S3, Secondary RO membrane filtration: Temperature control ≤12℃, using TM720D-400 type RO membrane filtration, pressure 2.0MPa; S4, Filtration with modified cation exchange resin: Temperature controlled ≤8℃, filtration with the modified cation exchange resin obtained in Example 1, pressure 0.17MPa, flow rate 8BV / h; S5, Anion exchange resin filtration: control temperature ≤8℃, use 201×7 type anion exchange resin for filtration, pressure 0.17MPa, flow rate 6BV / h; S6, Mixed ion exchange resin filtration: control temperature ≤8℃, use mixed ion exchange resin, wherein the volume ratio of modified Lewatit TP208 cation exchange resin to 201×7 anion exchange resin is 1:2, pressure 0.1MPa, flow rate 3BV / h.

[0053] The modified cation exchange resin has a service life of 170 hours.

[0054] Example 7 A method for preparing electronic-grade hydrogen peroxide, using the modified cation exchange resin obtained in Example 4, includes the following steps: S1, Dilution: Control the temperature ≤20℃, inject ultrapure water into 50%wt hydrogen peroxide, mix evenly to obtain 31.0%wt hydrogen peroxide; S2, Pretreatment: Filter with a 0.22μm microfiltration membrane to remove large particulate impurities at a pressure of 0.15 MPa; S3, Primary RO membrane filtration: Temperature control ≤12℃, using ESPA2-8040 type RO membrane filtration, pressure 3.0MPa; S3, Secondary RO membrane filtration: Temperature control ≤12℃, using ESPA2-8040 type RO membrane filtration, pressure 2.0MPa; S4, Filtration with modified cation exchange resin: control the temperature ≤8℃, filter with the modified cation exchange resin obtained in Example 1, pressure 0.16MPa, flow rate 7BV / h; S5, Anion exchange resin filtration: control temperature ≤8℃, use 201×7 type anion exchange resin for filtration, pressure 0.16MPa, flow rate 5BV / h; S6, Mixed ion exchange resin filtration: control temperature ≤8℃, use mixed ion exchange resin, wherein the volume ratio of modified Puromet MTS9570 cation exchange resin to 201×7 anion exchange resin is 1:2, pressure 0.08MPa, flow rate 2.6BV / h.

[0055] The modified cation exchange resin has a service life of 154 hours.

[0056] Comparative Example 1 A method for preparing electronic-grade hydrogen peroxide is basically the same as that in Example 5, except that unmodified 001×7 type cation exchange resin is used in steps S4 and S6.

[0057] The service life of the unmodified cation exchange resin is 72 hours.

[0058] The purity of the hydrogen peroxide obtained in Examples 5-7 was tested according to the standard HG / T5736-2020, and the results are listed in Table 2.

[0059] Table 2. Detection results of purified hydrogen peroxide category G5 Standard Example 5 Example 6 Example 7 Comparative Example 1 <![CDATA[Hydrogen peroxide (H2O2), w / %]]> 30.5-31.5 30.8 30.9 30.9 30.2 Chromaticity / Hazen ≤10 5 5 6 7 <![CDATA[Free acid (calculated as H2SO1) / ppm]]> ≤10 3 2 4 4 Total organic carbon (TOC) / ppm ≤10 5 4 5 6 Chloride (as Cl) / ppb ≤30 7 7 8 8 <![CDATA[Nitrate (calculated as NO3) / ppb]]> ≤30 4 4 3 4 <![CDATA[Phosphate (calculated as PO4) / ppb]]> ≤30 6 5 6 8 <![CDATA[Sulfate (calculated as SO4) / ppb]]> ≤30 4 3 3 5 Aluminum (Al) / ppt ≤10 2 3 2 12 Antimony (Sb) / ppt ≤10 ＜1 ＜1 ＜1 ＜1 Arsenic (As) / ppt ≤10 ＜1 ＜1 ＜1 ＜1 Barium (Ba) / ppt ≤10 ＜1 ＜1 ＜1 ＜1 Boron (B) / ppt ≤10 1 2 2 3 Calcium (Ca) / ppt ≤10 2 2 3 11 Chromium (Cr) / ppt ≤10 ＜1 ＜1 ＜1 6 Copper (Cu) / ppt ≤10 ＜1 ＜1 ＜1 3 Iron (Fe) / ppt ≤10 5 4 4 13 Lead (Pb) / ppt ≤10 ＜1 ＜1 ＜1 2 Lithium (Li) / ppt ≤10 ＜1 ＜1 ＜1 2 Magnesium (Mg) / ppt ≤10 ＜1 ＜1 ＜1 ＜1 Manganese (Mn) / ppt ≤10 2 ＜1 ＜1 8 Nickel (Ni) / ppt ≤10 ＜1 ＜1 ＜1 3 Potassium (K) / ppt ≤10 ＜1 ＜1 ＜1 ＜1 Sodium (Na) / ppt ≤10 5 4 4 9 Tin (Sn) / ppt ≤10 ＜1 ＜1 ＜1 ＜1 Titanium (Ti) / ppt ≤10 ＜1 ＜1 ＜1 ＜1 Vanadium (V) / ppt ≤10 ＜1 ＜1 ＜1 ＜1 Zinc (Zn) / ppt ≤10 ＜1 ＜1 3 7 As can be seen from Table 2, the impurity metal ion content of the products obtained in Examples 5-7 is better than the requirements of SEMI G5 standard, while the products treated with unmodified cation exchange resin have several impurity metal ion contents that are not up to standard; and the service life of the cation exchange resin is extended by more than twice.

Claims

1. A method for preparing electronic-grade hydrogen peroxide, characterized in that... The process includes the following steps: adjusting the concentration of the raw hydrogen peroxide, and then filtering it sequentially through a reverse osmosis membrane, a modified cation exchange resin, an anion exchange resin, and a mixed ion exchange resin to obtain electronic-grade hydrogen peroxide. The modified cation exchange resin is grafted with fullerene.

2. The method according to claim 1, characterized in that, The fullerene loading of the modified cation exchange resin was 0.0006-0.0015 mmol / g.

3. The method according to claim 1, characterized in that, The modified cation exchange resin is obtained by performing pretreatment, pore expansion, fullerene grafting, and posttreatment on the cation exchange resin in sequence. The cation exchange resin includes a styrene-divinylbenzene backbone and acidic active groups grafted onto the backbone.

4. The method according to claim 3, characterized in that, The pretreatment is as follows: first soaking in electronic grade hydrochloric acid, then rinsing with pure water until the pH of the effluent is 3.5-4.0, and finally soaking in anhydrous ethanol.

5. The method according to claim 3, characterized in that, The pore-expanding process involves immersing the resin in a pore-expanding agent, followed by gradient heating to remove the pore-expanding agent. The pore-expanding agent is a mixture of n-heptane and toluene in a volume ratio of 2-4:

1.

6. The method according to claim 5, characterized in that, The gradient heating is performed under vacuum conditions, where the temperature is sequentially increased from room temperature to 30-35℃, 50-55℃, and 65-70℃, and then maintained for at least 30 minutes after reaching the target temperature, with a heating rate ≤0.5℃ / min.

7. The method according to claim 3, characterized in that, The grafted fullerene is prepared by first preparing a fullerene pre-dispersion, then mixing it with resin, heating it to 50-60°C under nitrogen protection, adding an initiator, and reacting for 4-8 hours. The volume ratio of the resin to the pre-dispersion is 1:2-5.

8. The method according to claim 7, characterized in that, The fullerene predispersant has a fullerene powder to methyl methacrylate and anhydrous ethanol mass ratio of 1:15-25:60-100, and the initiator is used at 0.2-2% of the mass of methyl methacrylate. The initiator is selected from azobisisobutyronitrile or benzoyl peroxide.

9. The method according to claim 3, characterized in that, The post-treatment is as follows: the resin after grafting reaction is rinsed with anhydrous ethanol and pure water, and the water washing endpoint is when the conductivity of the effluent is ≤5μS / cm.

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