Method for recycling waste photoresist stripper solution

Abstract

This invention belongs to the field of chemical engineering technology, specifically relating to a method for the recycling of photoresist stripping solution waste. The invention first uses specially modified magnetic nanoparticles to demulsify, reduce viscosity, and remove impurities from the waste solution. Then, a zeolite film with a zirconium-tannic acid-polyethyleneimine metal-organic coordination network layer on its surface is used for pervaporation dehydration. Finally, adsorption, polishing, and recombination are performed, achieving the recycling of photoresist stripping solution waste. The resulting waste solution achieves a water removal rate >99.9% and an effective component recovery rate >99.5%.

Description

Technical Field

[0001] This invention belongs to the field of chemical engineering technology, and specifically relates to a method for the recycling of photoresist stripping solution waste liquid. Background Technology

[0002] Photoresist stripping solution is a key electronic chemical in the photolithography process of semiconductor wafer manufacturing and display panel (LCD / OLED) production. It is mainly used in the coating, development, and stripping of photoresist, as well as the cleaning of glass substrates. With the rapid expansion of the global semiconductor and display panel industries, the consumption of photoresist stripping solution continues to rise, and the production of waste photoresist stripping solution also continues to increase. Photoresist stripping solution is mainly composed of diethylene glycol methyl ether and monoethanolamine. Its waste liquid is characterized by complex composition, high toxicity, difficulty in degradation, and high COD value (up to 8000-12000 mg / L). Furthermore, if the large amount of high-value organic solvents and effective chemical components in the waste liquid are not recovered, it will result in huge resource waste and significantly increase the production costs of enterprises.

[0003] Currently, the treatment and regeneration technology for photoresist stripping waste liquid uses pervaporation membrane (PV) separation technology to replace the traditional high-energy-consuming vacuum distillation process, in order to achieve deep dehydration of the mixture of diethylene glycol methyl ether and organic amine. Among many permeable membranes, NaA-type zeolite molecular sieve membranes are theoretically the best choice for dehydration due to their uniform pore size and extreme hydrophilicity. However, in the actual regeneration process verification, the dehydration selectivity of NaA membranes when treating photoresist waste liquid usually drops sharply in less than 10 hours of operation, and the membrane module quickly becomes unusable. This technical bottleneck directly leads to the stagnation of the industrialization of pervaporation technology in this field. Research has revealed that NaA-type zeolites have an extremely low silicon-to-aluminum ratio. Under thermodynamically driven conditions at 65-75℃, the Al-O-Si bonds within the framework are subject to preferential attack from high concentrations of monoethanolamine (strongly alkaline and with strong nucleophilic properties) and dissociated hydroxyl ions in the waste liquid. This attack preferentially targets the partially positively charged aluminum atoms on the zeolite framework, triggering a violent "dealuminization reaction." This chemical etching leads to the irreversible dissolution and collapse of the three-dimensional lattice of the molecular sieve, resulting in a sharp amplification of intergranular defects and a complete loss of molecular sieving ability. Therefore, there is an urgent need to develop a composite molecular sieve membrane material with extreme alkali resistance and self-healing ability for grain boundary defects to address the industrial pain point of inorganic dehydration membrane framework dissolution caused by organic amine hydrothermal fluids.

[0004] Chinese patent application CN111302516A discloses a method for regenerating photoresist stripping solution waste liquid, specifically: (1) centrifugally separating the photoresist stripping solution waste liquid; (2) adding activated carbon to the photoresist stripping solution waste liquid treated in step (1) for decolorization treatment, and then filtering to obtain a colorless recovery liquid; (3) adding modified diatomaceous earth to the colorless recovery liquid, and then filtering to obtain usable photoresist stripping solution; wherein, the modified diatomaceous earth is obtained by modifying diatomaceous earth with sodium hydroxide solution and polyetherimide solution in sequence; (4) determining the content of useful components in the usable photoresist stripping solution, and replenishing the required effective components and amount of photoresist stripping solution to form regenerated photoresist stripping solution. This method employs physicochemical adsorption, utilizing the adsorption properties of modified diatomaceous earth to remove impurities. However, this method relies solely on physical purification, failing to achieve deep dehydration of the waste liquid and thus failing to meet the extremely low water content requirements of the photoresist stripping solution. Furthermore, it has limited effectiveness in removing metal ions and small-molecule organic impurities, resulting in the regenerated solution's purity failing to meet electronic-grade standards. Moreover, the process does not address the corrosion problem of strongly alkaline organic amines on the separation materials, nor does it utilize low-energy membrane separation technology. It still relies on intermittent adsorbent treatment and manual replenishment of components, leading to secondary pollution, high costs, and poor stability of the regenerated solution. Summary of the Invention

[0005] To address the technical problem of poor alkali resistance of the separation materials in the prior art, this invention provides a method for regenerating and utilizing waste photoresist stripping solution.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A method for recycling waste photoresist stripping solution includes the following steps: S1: Add magnetic particles to the waste liquid, sonicate, collect the liquid phase, and obtain coarse degumming regeneration liquid; S2: Heat the crude degummed regenerated liquid obtained in step S1 to 70-85℃, load it into a tubular module equipped with a composite dehydration membrane for pervaporation dehydration, and collect the intercepted liquid that does not pass through the composite dehydration membrane. S3: Cool the intercepted liquid obtained in step S2, pump it from top to bottom into a chromatographic fixed bed filled with mesoporous silica powder for physical adsorption, collect the effluent, add benzotriazole, stir until dissolved, and obtain photoresist stripping solution. The magnetic particles are aminated magnetic particles; the composite dehydration membrane is a zeolite membrane covered with a zirconium-tannic acid-polyethyleneimine metal-organic coordination network layer.

[0007] In the above scheme, the waste liquid is first demulsified, its viscosity reduced, and impurities removed by using specially modified magnetic nanoparticles. Then, a zeolite film with a zirconium-tannic acid-polyethyleneimine metal-organic coordination network layer on its surface is used for pervaporation and dehydration. Finally, adsorption, polishing, and recombination are carried out to achieve the regeneration and utilization of the photoresist stripping solution waste liquid. Among them, the magnetic particles not only adsorb photoresist molecules with steric hindrance through the amino groups on their surface, resulting in a significant decrease in fluid viscosity, but also capture copper ions through coordination, thus completely eliminating the contamination obstacles that easily cause pore blockage during subsequent membrane separation. The metal-organic coordination network layer on the surface of the zeolite membrane covered with the zirconium-tannic acid-polyethyleneimine metal-organic coordination network layer has a large steric hindrance and electrostatic repulsion, blocking diethylene glycol methyl ether and monoethanolamine outside the zeolite surface, preventing organic amine molecules from contacting the Al-O-Si bonds in the zeolite molecules, and improving the service life of the zeolite membrane. At the same time, polyethyleneimine is rich in polar groups, maintaining the hydrophilicity of the metal-organic coordination network layer. Water molecules can penetrate at high speed through the free volume pores inside the network layer via a dissolution-diffusion mechanism, improving the dehydration rate.

[0008] Furthermore, the preparation method of the magnetic particles in step S1 is as follows: the nanoparticles are added to anhydrous ethanol, ultrasonically dispersed, 3-aminopropyltriethoxysilane is added dropwise under stirring, the temperature is raised to 80-85℃, the reaction is stirred for 6-7 hours, solid-liquid separation is performed, the particles are washed 2-3 times with anhydrous ethanol, and vacuum dried to obtain the magnetic particles.

[0009] In the above scheme, a high density of amino functional groups is provided on the surface of magnetic nanoparticles through silane coupling reaction. These functional groups generate strong hydrogen bonds with the photoresist resin in the waste liquid and are also key active sites for complexing heavy metal ions.

[0010] Furthermore, the nanoparticles are one of nano-iron oxide, nano-nickel cobalt oxide, and nano-manganese ferrite.

[0011] Furthermore, the mass ratio of 3-aminopropyltriethoxysilane to nanoparticles is (14-15):20.

[0012] Further, the preparation method of the composite dehydration membrane in step S2 is as follows: dissolve tannic acid and polyethyleneimine in Tris-HCl buffer to obtain solution I; dissolve zirconium oxychloride in deionized water to obtain solution II; immerse the zeolite membrane in solution I, let it stand for 0.5-1 h, take it out and rinse it with deionized water, then immerse it in solution II, let it stand for 0.5-1 h, take it out and rinse it with deionized water, cycle the immersion 3 times, and cure and crosslink at 60-65℃ for 4-4.5 h to obtain the composite dehydration membrane.

[0013] In the above scheme, during the repeated immersion of the zeolite membrane in solutions I and II, the zirconium ions in the zirconium oxychloride aqueous solution, due to their high coordination number, can undergo extremely strong polydentate coordination with the catechol groups of tannic acid and the amino groups in polyethyleneimine molecules, forming a dense metal-organic coordination network layer on the surface of the zeolite membrane. Furthermore, the zirconium ions in solution II also exhibit a thermodynamic tendency to seek coordination with hydroxyl groups. While crosslinking with tannic acid and polyethyleneimine, they also actively pinnate to grain boundary defects on the surface of the zeolite membrane, forming stable covalent bonds with the silanol and aluminol hydroxyl groups at the grain ends. This behavior of repairing grain boundary defects through strong covalent and coordination bonds not only seals the permeation channels of macromolecular solvents in the waste liquid but also enhances the bonding force between the metal-organic coordination network layer and the zeolite membrane, improving the stability of the composite dehydration membrane under high-temperature fluid shear forces.

[0014] Furthermore, the zeolite membrane is prepared as follows: silicon dioxide, aluminum oxide, sodium oxide, potassium oxide, and water are mixed in a mass ratio of 1:0.05:0.26:0.09:14 and stirred for 2-3 hours to obtain a mother liquor; a clean porous alumina ceramic tube is vertically suspended in a high-pressure reactor, and the mother liquor is poured in to completely submerge the ceramic tube. After sealing the high-pressure reactor, it is transferred to a homogeneous hot air circulating oven, heated to 100-110℃, and kept at that temperature for crystallization for 24-28 hours. After cooling, the porous alumina ceramic tube is removed, rinsed with deionized water until the washing liquid is neutral, and dried to obtain the zeolite membrane.

[0015] In the above scheme, silicon dioxide, aluminum oxide, sodium oxide, potassium oxide and water are synthesized in situ hydrothermally in a specific ratio. By using low aluminum feed and synergistic regulation of potassium ions, a zeolite film with a higher silicon-to-aluminum ratio and a more stable framework structure can be obtained, which significantly improves alkali resistance and anti-dealumination performance. Using porous alumina as a support for one-step in-situ crystallization, the film is firmly bonded, dense and uniform, with few intergranular defects. Moreover, the above preparation process is mild and simple, without the need for complicated post-processing, and is suitable for industrial production.

[0016] Furthermore, the mass ratio of tannic acid, polyethyleneimine, and Tris-HCl buffer is (2-2.2):1:1000; the pH value of the Tris-HCl buffer is 8.5; and the concentration of solution II is 5-5.5 mmol / L.

[0017] Furthermore, in step S1, the mass ratio of the magnetic particles to the waste liquid is 1:(48-52), the frequency of the ultrasonic treatment is 40-50kHz, and the power density of the ultrasonic treatment is 0.3-0.5W / cm³. 3 The ultrasonic treatment time is 12-20 minutes.

[0018] In the above scheme, under the action of low-frequency ultrasound of 40-50kHz, the desorption of impurities and the adsorption of magnetic particles are simultaneously enhanced, which greatly shortens the desizing time. Moreover, the whole process does not require high temperature or oxidation environment, and will not cause the loss of components of photoresist stripping solution, thus improving the recovery rate of waste liquid.

[0019] Furthermore, the vaporization dehydration process described in step S2 is as follows: turn on the circulating vacuum pump on the feed liquid permeation side, adjust the fine-tuning valve to stabilize the absolute pressure on the permeation side at 200-250Pa, and vaporize and dehydrate for 2-2.5 hours.

[0020] Furthermore, the amount of benzotriazole used in step S3 is 0.15%-0.20% of the mass of the waste liquid in step S1.

[0021] Compared with existing technologies, the method for recycling photoresist stripping solution waste provided by this invention has the following technical advantages: (1) This invention abandons the easily soluble NaA film and selects a zeolite film with a high silicon-aluminum ratio that is more alkali resistant as the substrate. It also innovatively constructs an extremely thin zirconium-tannic acid-polyethyleneimine metal-organic coordination network layer on its surface and at the grain boundary, which completely blocks the chemical etching of the molecular sieve skeleton by organic amines and improves the equipment operation cycle. (2) The present invention eliminates the contamination of the membrane by macromolecular resin by physical separation of magnetic field at the front end, and effectively removes copper ions in waste liquid, thereby improving the efficiency of subsequent vaporization dehydration. (3) The present invention achieves a water removal rate of >99.9% and a recovery rate of >99.5% of effective components in waste liquid by coupling the magnetic field with the composite membrane process. Detailed Implementation

[0022] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments. Those skilled in the art can make various modifications based on the fundamental principles of the present invention, but all modifications that do not depart from the fundamental principles of the present invention are within its scope.

[0023] The preparation environment and equipment in the various embodiments and comparative examples of this invention are described as follows: The material synthesis and membrane separation operations in this embodiment are completed using specific experimental and process equipment platforms. The ultrasonic dispersion step in material preparation is carried out in an industrial-grade ultrasonic cleaning tank equipped with digital display temperature control and frequency sweep function, with a working frequency of 40 kHz. The in-situ hydrothermal synthesis reaction is completed in a stainless steel high-pressure reactor with a polytetrafluoroethylene liner, which is placed in a homogeneous hot air circulating oven with a temperature control accuracy of ±1℃. Membrane separation performance testing is conducted on a cross-flow pervaporation membrane separation device equipped with a liquid ring vacuum pump and a diaphragm pressurization pump. The device includes a stainless steel membrane module housing with guide baffles, and the absolute pressure on the permeate side is precisely maintained by a digital vacuum controller. The fixed-bed polishing step is carried out in a chromatography column with an inner diameter of 20 mm and a constant-temperature water jacket.

[0024] Preparation Example 1 The magnetic particles were prepared as follows: 20g of nano-iron oxide was added to 500mL of anhydrous ethanol and ultrasonically dispersed at a frequency of 40kHz for 30min. 14g of 3-aminopropyltriethoxysilane was added dropwise under stirring. The temperature was raised to 80℃ and the reaction was continuously stirred for 6h under reflux and condensation conditions. After the reaction was completed, the solid product was separated using an external permanent magnet, washed twice with anhydrous ethanol, and vacuum dried at an absolute pressure of 50Pa and 60℃ for 12h to obtain the magnetic particles.

[0025] Preparation Example 2 The magnetic particles were prepared as follows: 20g of nano-nickel cobalt oxide was added to 500mL of anhydrous ethanol and ultrasonically dispersed at a frequency of 40kHz for 30min. 15g of 3-aminopropyltriethoxysilane was added dropwise under stirring. The temperature was raised to 85℃ and the reaction was continuously stirred under reflux and condensation conditions for 7h. After the reaction was completed, the solid product was separated using an external permanent magnet, washed three times with anhydrous ethanol, and vacuum dried at an absolute pressure of 50Pa and 60℃ for 12h to obtain the magnetic particles.

[0026] Preparation Example 3 The magnetic particles were prepared as follows: 20g of nano-manganese ferrite was added to 500mL of anhydrous ethanol and ultrasonically dispersed at a frequency of 40kHz for 30min. 14.6g of 3-aminopropyltriethoxysilane was added dropwise under stirring. The temperature was raised to 84℃ and the reaction was continuously stirred under reflux and condensation conditions for 6.5h. After the reaction was completed, the solid product was separated using an external permanent magnet, washed three times with anhydrous ethanol, and vacuum dried at an absolute pressure of 50Pa and 60℃ for 12h to obtain the magnetic particles.

[0027] Preparation Example 4 The magnetic particles were prepared as follows: 20g of nano-iron oxide was added to 500mL of anhydrous ethanol and ultrasonically dispersed at a frequency of 40kHz for 30min. 14.8g of 3-aminopropyltriethoxysilane was added dropwise under stirring. The temperature was raised to 83℃ and the reaction was continuously stirred under reflux and condensation conditions for 6.3h. After the reaction was completed, the solid product was separated using an external permanent magnet, washed three times with anhydrous ethanol, and vacuum dried at an absolute pressure of 50Pa and 60℃ for 12h to obtain the magnetic particles.

[0028] Preparation Example 5 The preparation method of zeolite membrane is as follows: Silica, aluminum oxide, sodium oxide, potassium oxide and water are mixed in a mass ratio of 1:0.05:0.26:0.09:14 and stirred for 2 hours to obtain a mother liquor; a clean porous alumina ceramic tube is vertically suspended in a high-pressure reactor, and the mother liquor is poured in to completely submerge the ceramic tube. After sealing the high-pressure reactor, it is transferred to a homogeneous hot air circulating oven, heated to 100℃, and kept at that temperature for crystallization for 24 hours. After cooling, the porous alumina ceramic tube is removed, rinsed with deionized water until the washing solution is neutral, and dried at 100℃ for 6 hours to obtain the zeolite membrane.

[0029] The composite dehydration membrane was prepared as follows: 2g of tannic acid and 1g of polyethyleneimine were dissolved in 1000g of Tris-HCl buffer solution with a pH of 8.5 to obtain solution I; zirconium oxychloride was dissolved in deionized water to prepare solution II with a concentration of 5mmol / L; the zeolite membrane was immersed in solution I and allowed to stand for 0.5h, then rinsed with deionized water, and then immersed in solution II and allowed to stand for 0.5h, then rinsed with deionized water. The membrane was cycled and immersed 3 times, and then cured and crosslinked at 60℃ for 4h to obtain the composite dehydration membrane.

[0030] Preparation Example 6 The preparation method of zeolite membrane is as follows: Silica, aluminum oxide, sodium oxide, potassium oxide and water are mixed in a mass ratio of 1:0.05:0.26:0.09:14 and stirred for 3 hours to obtain a mother liquor; a clean porous alumina ceramic tube is vertically suspended in a high-pressure reactor, and the mother liquor is poured in to completely submerge the ceramic tube. After sealing the high-pressure reactor, it is transferred to a homogeneous hot air circulating oven, heated to 110℃, and kept at that temperature for crystallization for 28 hours. After cooling, the porous alumina ceramic tube is removed, rinsed with deionized water until the washing liquid is neutral, and dried at 100℃ for 6 hours to obtain a zeolite membrane.

[0031] The composite dehydration membrane was prepared as follows: 2.2 g of tannic acid and 1 g of polyethyleneimine were dissolved in 1000 g of Tris-HCl buffer solution with a pH of 8.5 to obtain solution I; zirconium oxychloride was dissolved in deionized water to prepare solution II with a concentration of 5.5 mmol / L; the zeolite membrane was immersed in solution I and allowed to stand for 1 h, then rinsed with deionized water, and then immersed in solution II and allowed to stand for 1 h, then rinsed with deionized water. This process was repeated 3 times, and the membrane was cured and crosslinked at 65℃ for 4.5 h to obtain the composite dehydration membrane.

[0032] Preparation Example 7 The preparation method of zeolite membrane is as follows: Silica, aluminum oxide, sodium oxide, potassium oxide and water are mixed in a mass ratio of 1:0.05:0.26:0.09:14 and stirred for 2.5 hours to obtain a mother liquor; a clean porous alumina ceramic tube is vertically suspended in a high-pressure reactor, and the mother liquor is poured in to completely submerge the ceramic tube. After sealing the high-pressure reactor, it is transferred to a homogeneous hot air circulating oven, heated to 105℃, and kept at that temperature for crystallization for 26 hours. After cooling, the porous alumina ceramic tube is removed, rinsed with deionized water until the washing solution is neutral, and dried at 100℃ for 6 hours to obtain the zeolite membrane.

[0033] The composite dehydration membrane was prepared as follows: 2.1 g of tannic acid and 1 g of polyethyleneimine were dissolved in 1000 g of Tris-HCl buffer solution with a pH of 8.5 to obtain solution I; zirconium oxychloride was dissolved in deionized water to prepare solution II with a concentration of 5.2 mmol / L; the zeolite membrane was immersed in solution I and allowed to stand for 0.7 h, then rinsed with deionized water, and then immersed in solution II and allowed to stand for 0.7 h, then rinsed with deionized water. The immersion was repeated 3 times, and the membrane was cured and crosslinked at 63℃ for 4.2 h to obtain the composite dehydration membrane.

[0034] Preparation Example 8 The preparation method of zeolite membrane is as follows: Silica, aluminum oxide, sodium oxide, potassium oxide and water are mixed in a mass ratio of 1:0.05:0.26:0.09:14 and stirred for 2.5 hours to obtain a mother liquor; a clean porous alumina ceramic tube is vertically suspended in a high-pressure reactor, and the mother liquor is poured in to completely submerge the ceramic tube. After sealing the high-pressure reactor, it is transferred to a homogeneous hot air circulating oven, heated to 108°C, and kept at that temperature for crystallization for 26 hours. After cooling, the porous alumina ceramic tube is removed, rinsed with deionized water until the washing solution is neutral, and dried at 100°C for 6 hours to obtain the zeolite membrane.

[0035] The composite dehydration membrane was prepared as follows: 2.15 g of tannic acid and 1 g of polyethyleneimine were dissolved in 1000 g of Tris-HCl buffer solution with a pH of 8.5 to obtain solution I; zirconium oxychloride was dissolved in deionized water to prepare solution II with a concentration of 5.4 mmol / L; the zeolite membrane was immersed in solution I and allowed to stand for 0.8 h, then rinsed with deionized water, and then immersed in solution II and allowed to stand for 0.8 h, then rinsed with deionized water. The immersion was repeated 3 times, and the membrane was cured and crosslinked at 63 °C for 4.3 h to obtain the composite dehydration membrane.

[0036] Example 1 A method for recycling waste photoresist stripping solution includes the following steps: S1: Add 1g of magnetic particles to 48g of waste liquid, at a frequency of 40kHz and a power density of 0.3W / cm³. 3 The mixture was ultrasonically treated for 12 minutes under the specified conditions, and the liquid phase was collected to obtain a coarse degummed regeneration solution; the magnetic particles were prepared by Preparation Example 1. S2: Heat the crude degummed regenerated liquid obtained in step S1 to 70°C, load it into a tubular module containing a composite dehydration membrane, turn on the circulating vacuum pump on the feed liquid permeation side, adjust the fine-tuning valve to stabilize the absolute pressure on the permeation side at 200Pa, vaporize and dehydrate for 2 hours, and collect the intercepted liquid that has not passed through the composite dehydration membrane; the composite dehydration membrane was prepared by preparation example 5. S3: Cool the intercepted liquid obtained in step S2, pump it from top to bottom into a chromatographic fixed bed filled with mesoporous silica powder for physical adsorption, collect the effluent, add 0.072g of benzotriazole, stir until dissolved, and obtain photoresist stripping solution.

[0037] Example 2 A method for recycling waste photoresist stripping solution includes the following steps: S1: Add 1g of magnetic particles to 52g of waste liquid, and heat at a frequency of 50kHz and a power density of 0.5W / cm³. 3 The mixture was ultrasonically treated for 20 min under the specified conditions, and the liquid phase was collected to obtain a coarse degummed regeneration solution; the magnetic particles were prepared by Preparation Example 2. S2: Heat the crude degummed regenerated liquid obtained in step S1 to 85°C, load it into a tubular module containing a composite dehydration membrane, turn on the circulating vacuum pump on the feed liquid permeation side, adjust the fine-tuning valve to stabilize the absolute pressure on the permeation side at 250 Pa, vaporize and dehydrate for 2.5 h, and collect the choked liquid that has not passed through the composite dehydration membrane; the composite dehydration membrane was prepared by preparation example 6. S3: Cool the intercepted liquid obtained in step S2, pump it from top to bottom into a chromatographic fixed bed filled with mesoporous silica powder for physical adsorption, collect the effluent, add 0.104g of benzotriazole, stir until dissolved, and obtain photoresist stripping solution.

[0038] Example 3 A method for recycling waste photoresist stripping solution includes the following steps: S1: Add 1g of magnetic particles to 49g of waste liquid, at a frequency of 45kHz and a power density of 0.4W / cm³. 3 The mixture was ultrasonically treated for 15 minutes under the specified conditions, and the liquid phase was collected to obtain a coarse degummed regeneration solution; the magnetic particles were prepared by Preparation Example 3. S2: Heat the crude degummed regenerated liquid obtained in step S1 to 75°C, load it into a tubular module containing a composite dehydration membrane, turn on the circulating vacuum pump on the feed liquid permeation side, adjust the fine-tuning valve to stabilize the absolute pressure on the permeation side at 225 Pa, vaporize and dehydrate for 2.2 h, and collect the intercepted liquid that has not passed through the composite dehydration membrane; the composite dehydration membrane was prepared by preparation example 7; S3: Cool the intercepted liquid obtained in step S2, pump it from top to bottom into a chromatographic fixed bed filled with mesoporous silica powder for physical adsorption, collect the effluent, add 0.0882g of benzotriazole, stir until dissolved, and obtain photoresist stripping solution.

[0039] Example 4 A method for recycling waste photoresist stripping solution includes the following steps: S1: Add 1g of magnetic particles to 51g of waste liquid, at a frequency of 45kHz and a power density of 0.4W / cm³. 3 The mixture was ultrasonically treated for 18 minutes under the specified conditions, and the liquid phase was collected to obtain a coarse degummed regeneration solution; the magnetic particles were prepared by Preparation Example 4. S2: Heat the crude degummed regenerated liquid obtained in step S1 to 80°C, load it into a tubular module containing a composite dehydration membrane, turn on the circulating vacuum pump on the feed liquid permeation side, adjust the fine-tuning valve to stabilize the absolute pressure on the permeation side at 230 Pa, vaporize and dehydrate for 2.4 h, and collect the choked liquid that has not passed through the composite dehydration membrane; the composite dehydration membrane was prepared by preparation example 8; S3: Cool the intercepted liquid obtained in step S2, pump it from top to bottom into a chromatographic fixed bed filled with mesoporous silica powder for physical adsorption, collect the effluent, add 0.0867g of benzotriazole, stir until dissolved, and obtain photoresist stripping solution.

[0040] Comparative Example 1 The method for recycling the photoresist stripping solution waste liquid in this comparative example is similar to that in Example 4. The difference between this comparative example and Example 4 is that no magnetic particles were added in step S1 of this comparative example.

[0041] Comparative Example 2 The method for recycling the photoresist stripping solution waste liquid in this comparative example is similar to that in Example 4. The difference between this comparative example and Example 4 is that the magnetic particles were not subjected to amination treatment in this comparative example.

[0042] Comparative Example 3 The method for recycling the photoresist stripping solution waste in this comparative example is similar to that in Example 4. The difference between this comparative example and Example 4 is that a T-type zeolite membrane is used instead of a composite dehydration membrane in step S2. The preparation method of the T-type zeolite membrane is as follows: silicon dioxide, aluminum oxide, sodium oxide, potassium oxide and water are mixed in a mass ratio of 1:0.05:0.26:0.09:14 and stirred for 2.5 hours to obtain a mother liquor. A clean porous alumina ceramic tube is vertically suspended in a high-pressure reactor, and the mother liquor is poured in to completely submerge the ceramic tube. After sealing the high-pressure reactor, it is transferred to a homogeneous hot air circulating oven, heated to 108°C, and kept at that temperature for 26 hours for crystallization. After cooling, the porous alumina ceramic tube is taken out, rinsed with deionized water until the washing solution is neutral, and dried at 100°C for 6 hours to obtain a T-type zeolite membrane.

[0043] Comparative Example 4 The method for recycling the photoresist stripping solution waste liquid in this comparative example is similar to that in Example 4. The difference between this comparative example and Example 4 is that polyethyleneimine was not added during the preparation of the composite dehydration membrane in this comparative example.

[0044] Comparative Example 5 The method for regenerating and utilizing the photoresist stripping solution waste liquid in this comparative example is similar to that in Example 4. The difference between this comparative example and Example 4 is that conventional zeolite molecular sieves are used instead of composite dehydration membranes in this comparative example.

[0045] Test case In this experimental example, a waste liquid was prepared for testing. The preparation method of the waste liquid was as follows: First, 700.0g of diethylene glycol methyl ether, 200.0g of monoethanolamine, 50.0g of deionized water, 49.0g of positive photoresist resin, and 1.0g of anhydrous copper sulfate were added to the mixing tank in sequence. The mechanical stirring device was started, and the mixture was stirred continuously at 400rpm for 4.0 hours under mild heating conditions of 40℃. After the solid resin and metal salt were completely dissolved, a simulated photoresist stripping waste liquid with a total mass of 1.0kg, a dark blue-green appearance, and high viscosity was prepared.

[0046] The effective components of the photoresist stripping solution waste liquid after regeneration were analyzed by liquid chromatography, and the concentrations of water, monoethanolamine, copper ions in the tack liquid, breakthrough time of the waste liquid (i.e., the time required for the membrane to run continuously under high temperature and strong alkali until the separation factor decreases by 10%) and appearance of the tack liquid were recorded.

[0047] The experimental results are shown in Table 1.

[0048] Table 1 Test Results

[0049] As shown in Table 1, the photoresist stripping solution waste recycling method provided by the present invention achieves a water removal rate of >99.9% in the waste liquid, effectively removes copper ions in the waste liquid through magnetic particles, and effectively prolongs the penetration time of the zeolite membrane by coating the zeolite membrane with a metal-organic coordination network layer, thereby improving the equipment operation cycle.

[0050] Example 4 showed the best results and is the preferred embodiment of the present invention.

[0051] Compared to Example 4, Comparative Example 1 did not add magnetic particles, and Comparative Example 2 did not perform amination treatment on the magnetic particles, but the concentration of copper ions increased. This indicates that the magnetic particles can effectively remove copper ions, and the amination treatment of the magnetic particles is the key to improving their copper ion removal capacity. Comparative Example 3 used a T-type zeolite membrane instead of a composite dehydration membrane, Comparative Example 4 did not add polyethyleneimine during the preparation of the composite dehydration membrane, and Comparative Example 5 used a conventional zeolite molecular sieve instead of a composite dehydration membrane, but the water content increased, the monoethanolamine content decreased, and the penetration time shortened. This indicates that ordinary zeolite membranes and zeolite molecular sieves degrade rapidly under high-temperature organic amine erosion, resulting in a short service life. Although the inorganic cross-linking network formed by tannic acid and zirconium ions provides some protection for the zeolite membrane, it lacks the hydrogen bond water transport channels provided by polyethyleneimine, leading to a decrease in water removal capacity and selectivity.

[0052] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for regenerating waste photoresist stripping solution, characterized in that, Includes the following steps: S1: Add magnetic particles to the waste liquid, sonicate, collect the liquid phase, and obtain coarse degumming regeneration liquid; S2: Heat the crude degummed regenerated liquid obtained in step S1 to 70-85℃, load it into a tubular module equipped with a composite dehydration membrane for pervaporation dehydration, and collect the intercepted liquid that does not pass through the composite dehydration membrane. S3: Cool the intercepted liquid obtained in step S2, pump it from top to bottom into a chromatographic fixed bed filled with mesoporous silica powder for physical adsorption, collect the effluent, add benzotriazole, stir until dissolved, and obtain photoresist stripping solution. The magnetic particles are aminated magnetic particles; the composite dehydration membrane is a zeolite membrane covered with a zirconium-tannic acid-polyethyleneimine metal-organic coordination network layer.

2. The method for regenerating photoresist stripping solution waste liquid according to claim 1, characterized in that, The preparation method of the magnetic particles in step S1 is as follows: nanoparticles are added to anhydrous ethanol, ultrasonically dispersed, 3-aminopropyltriethoxysilane is added dropwise under stirring, the temperature is raised to 80-85℃, the reaction is stirred for 6-7 hours, solid-liquid separation is performed, the particles are washed 2-3 times with anhydrous ethanol, and vacuum dried to obtain magnetic particles.

3. The method for regenerating photoresist stripping solution waste liquid according to claim 2, characterized in that, The nanoparticles are one of nano-iron oxide, nano-nickel cobalt oxide, and nano-manganese ferrite.

4. The method for regenerating photoresist stripping solution waste liquid according to claim 2, characterized in that, The mass ratio of 3-aminopropyltriethoxysilane to nanoparticles is (14-15):

20.

5. The method for regenerating photoresist stripping solution waste liquid according to claim 1, characterized in that, The method for preparing the composite dehydration membrane in step S2 is as follows: Tannic acid and polyethyleneimine are dissolved in Tris-HCl buffer to obtain solution I; zirconium oxychloride is dissolved in deionized water to obtain solution II; the zeolite membrane is immersed in solution I, allowed to stand for 0.5-1 h, taken out and rinsed with deionized water, then immersed in solution II, allowed to stand for 0.5-1 h, taken out and rinsed with deionized water, and the immersion is repeated 3 times, and cured and crosslinked at 60-65℃ for 4-4.5 h to obtain the composite dehydration membrane.

6. The method for regenerating photoresist stripping solution waste liquid according to claim 5, characterized in that, The zeolite membrane is prepared as follows: Silica, aluminum oxide, sodium oxide, potassium oxide, and water are mixed in a mass ratio of 1:0.05:0.26:0.09:14 and stirred for 2-3 hours to obtain a mother liquor. A clean porous alumina ceramic tube is vertically suspended in a high-pressure reactor, and the mother liquor is poured in to completely submerge the ceramic tube. After sealing the high-pressure reactor, it is transferred to a homogeneous hot air circulating oven and heated to 100-110℃ for crystallization for 24-28 hours. After cooling, the porous alumina ceramic tube is removed, rinsed with deionized water until the washing liquid is neutral, and dried to obtain the zeolite membrane.

7. The method for regenerating photoresist stripping solution waste liquid according to claim 5, characterized in that, The mass ratio of tannic acid, polyethyleneimine, and Tris-HCl buffer is (2-2.2):1:1000; the pH value of the Tris-HCl buffer is 8.5; and the concentration of solution II is 5-5.5 mmol / L.

8. The method for regenerating photoresist stripping solution waste liquid according to claim 1, characterized in that, In step S1, the mass ratio of magnetic particles to waste liquid is 1:(48-52), the frequency of ultrasonic treatment is 40-50kHz, and the power density of ultrasonic treatment is 0.3-0.5W / cm³. 3 The ultrasonic treatment time is 12-20 minutes.

9. The method for regenerating photoresist stripping solution waste liquid according to claim 1, characterized in that, The vaporization dehydration process described in step S2 is as follows: turn on the circulating vacuum pump on the feed liquid permeation side, adjust the fine-tuning valve to stabilize the absolute pressure on the permeation side at 200-250Pa, and vaporize and dehydrate for 2-2.5 hours.

10. The method for regenerating photoresist stripping solution waste liquid according to claim 1, characterized in that, The amount of benzotriazole used in step S3 is 0.15%-0.20% of the mass of the waste liquid in step S1.

Images