Method for purifying electronic grade NMP (N-Methyl Pyrrolidone)

Abstract

The invention relates to a method for purifying electronic-grade NMP (N-Methyl Pyrrolidone), which comprises the following steps of: mixing metal ions, carboxylic acid ligands, a solvent and HBF4 (Hepatitis B Factor 4), and uniformly mixing according to a certain proportion at 230-260 DEG C; performing solvothermal reaction on the obtained mixture to obtain MOF; mixing the obtained MOF material and strongly acidic resin according to a certain proportion, filling an adsorption column with the mixture, injecting NMP into the adsorption column at a certain flow rate, and staying for a certain period of time; and collecting the treated NMP solution at the outlet of the adsorption column to obtain purified NMP. According to the method, most of metal impurities in the NMP solution can be efficiently removed, and the electronic grade NMP product larger than or equal to 99.999% can be obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical engineering, and in particular relates to a method for purifying electronic-grade NMP and an adsorption material for removing metal impurities. Background Art

[0002] N-methylpyrrolidone (NMP) has high chemical stability, low toxicity, low volatility, and biodegradability. It is widely used as an excellent organic solvent. NMP was first used in petrochemicals, pesticides, coatings and other fields, but as the purity of NMP continues to increase, electronic-grade NMP is used as a semiconductor solvent, lithium battery, precision instrument and other electronic products production and maintenance cleaning agent, and disk photoresist stripping liquid and other high-end fields due to its high purity (usually above 99.8%) and low impurities (such as metal ion content at the μg / L level). The purity and impurity content of electronic-grade NMP have a crucial impact on the yield, electrical performance and reliability of integrated circuits. Most metal impurity content is required to be controlled at the 1μg / kg level, and even some key metal impurity content is required to be controlled at the 0.1μg / kg level.

[0003] In the prior art, NMP is produced by conventional distillation. Although distillation can improve the quality and purity of NMP to a certain extent, there are still certain impurities, such as metal impurities. The metal impurities in NMP mainly come from: 1. trace metal impurities introduced in the production environment and manufacturing process; 2. metal impurities introduced by humans during transportation and storage; 3. metal pollution introduced by the external environment during use.

[0004] These metal impurities cannot be separated by conventional distillation and are very difficult to purify, especially for the preparation and production of electronic-grade NMP (99.99%), which poses a severe challenge to the system and process design requirements.

[0005] There is a method of using ion exchange resin to adsorb and separate metal impurities in NMP in the prior art. Macroporous and strong base anion resins are used to remove metal impurities in NMP by surface chemical adsorption. However, the surface groups of ion resins are single and the pore structure is uncontrollable, so the adsorption efficiency is low and the adsorption effect is poor. Therefore, the controllability of the pore structure and surface functional groups of the adsorption material is the key to improving the adsorption and removal effect of metal impurities in NMP. Summary of the invention

[0006] In order to solve the problems of the existing NMP purification technology, the purpose of the present invention is to provide a method for purifying electronic grade NMP and a composite material for removing metal impurities, which can achieve efficient removal of metal impurities in NMP distillation products, and the desorption process is simple, which can significantly extend the effectiveness of the adsorption resin material.

[0007] The present invention is achieved through the following technical solutions: The invention provides a method for purifying electronic-grade NMP and an adsorption material for removing metal impurities. A MOF material is added with a strong acid resin and then filled into an adsorption column. NMP is injected into the adsorption column, and after retention and adsorption, an NMP solution after adsorption is collected to obtain electronic-grade NMP.

[0008] The MOF material is obtained by mixing metal ions, carboxylic acid ligands, solvent and HBF4 and then performing a solvent thermal reaction at 230-260°C.

[0009] The metal ions include any one of zinc ions, iron ions, copper ions, chromium ions and zirconium ions.

[0010] The carboxylic acid ligand is selected from any one of 4,4'-biphenyl dicarboxylic acid, 4,4"-terphenyl dicarboxylic acid, 1,3,5-tris(4-carboxyphenyl)benzene, 2-aminoterephthalic acid, 2-nitroterephthalic acid, 2,5-diaminoterephthalic acid, and 2,5-thiophene dicarboxylic acid or a mixture thereof.

[0011] The solvent is selected from any one of ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, pentaerythritol, diethylene glycol, dipropylene glycol, trimethylolpropane or a mixture thereof.

[0012] The mass ratio of metal ion, organic ligand and solvent is (1-10): (0.1-1): (10-40).

[0013] The strong acid resin is selected from any one of D113FC, UPW650, SC980N, SC650U, ZGNR6020 and MB1401.

[0014] The mass ratio of MOF material to strong acid resin is 0.1-1:20-200.

[0015] NMP is injected from the bottom of the adsorption column, and the injection flow rate of NMP is 0.1 mL / min~5 L / min; the residence time of NMP in the adsorption column is 10 sec~100 h; the total flow rate of NMP is 0.01~100 t / h.

[0016] The electronic grade NMP prepared by any of the above methods has a metal impurity content of 0.1 ppb ~50 ppb, preferably a metal impurity content of 0.1 ppb ~40 ppb, preferably a metal impurity content of 0.1 ppb ~20 ppb, preferably a metal impurity content of 0.1 ppb ~10 ppb, and a purity of ≥99.999%.

[0017] The benefit of the present invention is that a MOF material with a certain crystal structure is obtained by regulating metal ions, organic ligands and reaction conditions, and the prepared MOF material has a small nanoparticle size. After being added to a strong acid resin, the surface charge can be enhanced, the resin adsorption capacity can be increased, and the resin's useful life can be extended to 150 hours or more. In the resin regeneration process, desorption is simple and the regeneration capacity is strong. The present invention adds a strong acid resin to the MOF material and fills it in an adsorption column. The present invention can achieve efficient removal of most metal impurities in an NMP solution, and can obtain ≥99.999% electronic grade NMP products. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the Cu-MOF material of Example 1 of the present invention.

[0019] Figure 2 This is the Fe-MOF material of Example 1 of the present invention.

[0020] Figure 3 This is the Zr-MOF material of Example 1 of the present invention.

[0021] Figure 4 This is the Cr-MOF material of Example 1 of the present invention. DETAILED DESCRIPTION

[0022] A method for purifying electronic grade NMP and an adsorbent material for removing metal impurities, comprising the following steps: A method for purifying electronic grade NMP and an adsorbent material for removing metal impurities, comprising the following steps: A method for purifying electronic grade NMP and an adsorbent material for removing metal impurities, wherein metal ions, carboxylic acid ligands, solvents and HBF4 are mixed at 230-260°C and mixed evenly in a certain proportion; the obtained mixture is subjected to a solvothermal reaction to obtain MOF; the obtained MOF material is mixed with a strong acid resin in a certain proportion, filled in an adsorption column, NMP is injected into the adsorption column at a certain flow rate, and stays for a certain time; the NMP solution after treatment is collected at the outlet of the adsorption column to obtain purified NMP. The present invention can achieve efficient removal of most metal impurities in the NMP solution, and can obtain ≥99.999% electronic grade NMP products.

[0023] Example 1 Preparation of MOF materials: Preparation of Cu-MOF material: 10 g of copper nitrate was dissolved in 30 ml of dipropylene glycol solution, 2,5-thiophenedicarboxylic acid was added at a mass ratio of 1:0.2, and a solvothermal reaction was carried out at 230 °C in a nitrogen environment for 12 h to obtain the Cu-MOF material.

[0024] Preparation of Fe-MOF material: Ferric nitrate and 2-nitroterephthalic acid ligand were dissolved in trimethylolpropane with a mixing mass ratio of 1:0.2:40. In an argon environment, the solution was heated to 250°C in a hydrothermal reactor and reacted for 15 h to obtain Fe-MOF material.

[0025] Preparation of Zr-MOF material: Zirconium tetrachloride, 4,4'-biphenyldicarboxylic acid, and 1,4-butanediol were mixed in a mass ratio of 1:0.5:30. The solution was heated to 230°C in a hydrothermal reactor under air conditions and reacted for 14 h. Zr-MOF material was obtained after centrifugation.

[0026] Preparation of Cr-MOF material: The mass ratio of chromium nitrate, 2,5-diaminoterephthalic acid and pentaerythritol is 1:0.5:30. Under air conditions, the solution is heated to 230°C in a hydrothermal reactor and reacted for 14 hours. After centrifugation, Zr-MOF material is obtained.

[0027] Where does the NMP solution in the embodiment targeted by the present invention come from and what are its physical and chemical properties? The key points should be to highlight the metal ions and their contents. V 50-100ppm, Cu 70-120ppm, Zn 60-80ppm, Ba 50-90ppm, Na 200-500ppm, Mg 100-200ppm, K 100-300ppm, Ca 120-340ppm.

[0028] Example 2 The Cu-MOF material prepared in Example 1 was mixed with D113FC at a mass ratio of 1:30, and then filled into a 200 mL adsorption column. NMP was injected from the bottom of the adsorption column. The injection flow rate of NMP was 3 mL / min, the residence time was 0.5 h, and the total flow rate of NMP was 0.1 kg / h. The treated NMP was collected at the outlet of the adsorption column. The purified NMP contained 5.5 ppb of V, 0.8 ppb of Cu, 9.4 ppb of Zn, 6.2 ppb of Ba, 7.3 ppb of Na, 6.6 ppb of Mg, 4.9 ppb of K, and 7.8 ppb of Ca, with a purity of ≥99.999%.

[0029] After running for 70 hours in the above process, the purified NMP contained 7.9 ppb of V, 4.7 ppb of Cu, 14.6 ppb of Zn, 8.8 ppb of Ba, 8.2 ppb of Na, 20.4 ppb of Mg, 19.7 ppb of K and 9.5 ppb of Ca, with a purity of ≥99.999%.

[0030] After running for 150 hours, the purified NMP contained V 10.5ppb, Cu 9.3ppb, Zn 17.6ppb, Ba19.5ppb, Na 26.9ppb, Mg 39.5ppb, K 24.3ppb, and Ca 17.6ppb, with a purity of ≥99.999%.

[0031] After the mixed resin in the above-mentioned operation for 150 hours was rinsed with deionized water at a rate of 2BV / H for 30 minutes, it was then rinsed with a regeneration agent at a rate of 5BV / H for 50 minutes, and then rinsed with deionized water at a rate of 2BV / H for 30 minutes to obtain a regenerated mixed resin. The regeneration agent is a mixture of sodium citrate, sodium gluconate, and sodium hexametaphosphate in a mass ratio of 8:5:20. The raw materials of the regeneration agent are all electronic grade raw materials, and when the regeneration agent is used for rinsing, the mass concentration of the regeneration agent is 12%.

[0032] The recovered mixed resin is subjected to the above-mentioned process for removing metal ions, and the purified NMP contains 9.6 ppb of V, 1.9 ppb of Cu, 8.2 ppb of Zn, 10.3 ppb of Ba, 5.9 ppb of Na, 4.7 ppb of Mg, 6.3 ppb of K, and 11.2 ppb of Ca, with a purity of ≥99.999%.

[0033] After running for 72 hours in the above process, the purified NMP contained 22.7 ppb of V, 30.9 ppb of Cu, 34.5 ppb of Zn, 22.8 ppb of Ba, 40.9 ppb of Na, 41.3 ppb of Mg, 45.5 ppb of K and 22.5 ppb of Ca, with a purity of ≥99.999%.

[0034] Example 3 The Fe-MOF material prepared in Example 1 was mixed with UPW650 and MB1401 in a mass ratio of 0.5:10:10, and then filled into a 500 mL adsorption column. NMP was injected from the bottom of the adsorption column. The injection rate of NMP was 100 mL / min, the residence time was 1 h, and the total flow rate of NMP was 1 kg / h; the treated NMP was collected at the outlet of the adsorption column. The purified NMP contained 12.3 ppb of V, 1.6 ppb of Cu, 14.2 ppb of Zn, 22.1 ppb of Ba, 13.5 ppb of Na, 0.7 ppb of Mg, 1.1 ppb of K, and 2.8 ppb of Ca, with a purity of ≥99.999%.

[0035] Example 4 The Cr-MOF material prepared in Example 1 was mixed with SC980N, SC650U and MB1401 in a mass ratio of 0.1:1:10:5, and the mixture was filled into a 10 L adsorption column. NMP was injected from the bottom of the adsorption column. The injection rate of NMP was 50 mL / min, the residence time was 0.5 h, and the total flow rate of NMP was 0.04 kg / h. The treated NMP was collected at the outlet of the adsorption column. The purified NMP contained 22.4 ppb of V, 1.6 ppb of Cu, 4.9 ppb of Zn, 17.4 ppb of Ba, 1.1 ppb of Na, 1.4 ppb of Mg, 2.8 ppb of K, and 7.3 ppb of Ca, with a purity of ≥99.999%.

[0036] Example 5 The Zr-MOF material and the Cr-MOF material prepared in Example 1 were mixed in a volume ratio of 1:1 to obtain a mixed MOF material, and the mixed MOF material was mixed with ZGNR6020, D113FC and MB1401 in a mass ratio of 0.5:5:5:20, and then filled into a 500 mL adsorption column, and NMP was injected from the bottom of the adsorption column. The injection flow rate of NMP was 150 mL / min, the residence time was 1 h, and the total flow rate of NMP was 0.1 kg / h; the treated NMP was collected at the outlet of the adsorption column, and the purified NMP reached the electronic grade standard. The purified NMP contained 1.7 ppb of V, 0.8 ppb of Cu, 11.6 ppb of Zn, 10.2 ppb of Ba, 0.9 ppb of Na, 1.0 ppb of Mg, 0.9 ppb of K, and 2.2 ppb of Ca, with a purity of ≥99.999%.

[0037] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for purifying electronic grade NMP, characterized in that, The method comprises the following steps: adding a strong acid resin to the MOF material and then filling the MOF material into an adsorption column, injecting NMP into the adsorption column, performing retention adsorption, collecting the adsorbed NMP solution, and obtaining electronic grade NMP. The carboxylic acid ligands include terephthalic acid, trimesic acid, 4,4'-biphenyl dicarboxylic acid, 4,4"-terphenyl dicarboxylic acid, 1,3,5-tri(4-carboxyphenyl)benzene, 2-aminoterephthalic acid, 2-nitroterephthalic acid, 2,5- The invention relates to a solvent selected from any one of diaminoterephthalic acid and 2,5-thiophenedicarboxylic acid or a mixture thereof; the solvent is selected from any one of ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, pentaerythritol, diethylene glycol, dipropylene glycol and trimethylolpropane or a mixture thereof; and the strong acid resin is selected from any one of D113FC, UPW650, SC980N, SC650U, ZGNR6020 and MB1401.

2. The method for purifying electronic-grade NMP according to claim 1, wherein The MOF material is obtained by mixing metal ions, carboxylic acid ligands, solvent and HBF4 and then performing a solvent thermal reaction at 230-260°C.

3. The method for purifying electronic-grade NMP according to claim 2, wherein The metal ions include any one of zinc ions, iron ions, copper ions, chromium ions and zirconium ions.

4. The method for purifying electronic-grade NMP according to claim 1, wherein The mass ratio of metal ion, organic ligand and solvent is (1-10): (0.1-1): (10-40).

5. The method for purifying electronic-grade NMP according to claim 1, wherein The mass ratio of MOF material to strong acid resin is 0.1-1:20-200.

6. The method for purifying electronic-grade NMP according to claim 1, wherein NMP is injected from the bottom of the adsorption column, and the injection flow rate of NMP is 0.1 mL / min~5 L / min; the residence time of NMP in the adsorption column is 10 sec~100 h; the total flow rate of NMP is 0.01~100 t / h.

7. The method for purifying electronic-grade NMP according to any one of claims 1 to 6, characterized in that: The electronic grade NMP prepared by the method has a metal impurity content of 0.1 ppb to 50 ppb and a purity of ≥99.999%.

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