Electronic grade propylene glycol methyl ether acetate production system and method

Abstract

The invention relates to an electronic grade propylene glycol methyl ether acetate production system and method. The production system comprises a light component removal rectifying tower (1), a heavy component removal rectifying tower (2), a micro-filter (3), an anion and cation remover (4), a precision rectifying tower (5) and a nano-filter (6) which are connected in sequence, the light component removal rectifying tower (1) and the precision rectifying tower (5) are also connected with a recovery tower (7); industrial-grade propylene glycol methyl ether acetate is used as a raw material, large particles are removed through rectification purification and microfiltration, metal ions and non-metal ions in the propylene glycol methyl ether acetate are removed through a zwitterion remover, water introduced by the zwitterion remover is removed through a precise rectification tower, and finally the semiconductor-grade propylene glycol methyl ether acetate is obtained through nanofiltration. Compared with the prior art, the method has the advantages of high recovery rate, short flow, good separation effect, high process continuity and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of propylene glycol methyl ether acetate production, and particularly to a production system and method for electronic-grade propylene glycol methyl ether acetate. Background Art

[0002] Propylene glycol methyl ether acetate (PGMEA) is a high-grade solvent. It has three structures of ether bond, ester group and alkyl group in its molecule, and has a certain solubility for both non-polar substances and polar substances. Therefore, it is mainly used to remove dirt and residues on silicon wafers, photoresists and other electronic components. Its purity and cleanliness have a very significant impact on the yield, electrical properties and reliability. With the continuous development of high-end lithography processing technology, it is required that the purity of propylene glycol methyl ether acetate must meet the requirements of SEMI C12 standard formulated by the International Organization for Semiconductor Equipment and Materials in order to meet its application in high-end manufacturing fields such as semiconductor chip manufacturing.

[0003] Ultra-pure and high-purity propylene glycol methyl ether acetate is usually purified from industrial-grade propylene glycol methyl ether acetate. Patent CN201911319061.3 prepares electronic-grade propylene glycol methyl ether acetate by adding an appropriate amount of metal compound during the rectification process. Only rectifying and purifying propylene glycol methyl ether acetate has relatively high energy consumption, and the recovery rate of propylene glycol methyl ether acetate is not described. CN202111654946.6 purifies industrial-grade propylene glycol methyl ether acetate by batch rectification, and the process is not continuous. Summary of the Invention

[0004] The purpose of the present invention is to provide a production system and method for electronic-grade propylene glycol methyl ether acetate, which has a high recovery rate and strong process continuity.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A production system for electronic-grade propylene glycol methyl ether acetate includes a light component removal rectification column, a heavy component removal rectification column, a microfilter, an anion-cation remover, a precision rectification column, and a nanofiltration membrane, which are connected in sequence;

[0006] The light component removal rectification column and the precision rectification column are also connected to a recovery column.

[0007] The present invention uses industrial-grade propylene glycol methyl ether acetate as the raw material, with a mass content of propylene glycol methyl ether acetate above 99%. Through rectification and purification, large particles are removed by microfiltration, then metal ions and non-metal ions in propylene glycol methyl ether acetate are removed by an anion-cation remover, and water introduced by the anion-cation remover is removed by a precision rectification column. Finally, semiconductor-grade propylene glycol methyl ether acetate is obtained through nanofiltration.

[0008] Preferably, the number of theoretical plates of the light component removal distillation column is 10 - 50, the operating pressure is atmospheric pressure or slightly positive pressure, the top temperature is 160 - 180 °C, and the reflux ratio is 10 - 30.

[0009] Preferably, the light component removal distillation column is a conventional distillation column, made of polished stainless steel, and includes a condenser and a reboiler.

[0010] Preferably, the number of theoretical plates of the heavy component removal distillation column is 10 - 50, the operating pressure is negative pressure, the top temperature is 80 - 150 °C, and the reflux ratio is 10 - 30.

[0011] Preferably, the heavy component removal distillation column is a conventional distillation column, made of polished stainless steel, and includes a condenser and a reboiler.

[0012] Preferably, the filter membrane of the microfilter is one or more of polytetrafluoroethylene membrane, polyethersulfone membrane, polyvinylidene fluoride membrane, polyimide membrane, and polyamide membrane with a pore size of 0.1 - 0.5 μm.

[0013] Preferably, the anion and cation remover uses ion exchange resin or ion exchange fiber with a pore size of 0.6 mm or less and a particle size uniformity coefficient of 1.1 or less.

[0014] More preferably, the ion exchange resin is selected from sulfonic acid group styrene resin, carboxyl group styrene resin, quaternary amine group styrene resin, perfluorosulfonic acid resin, and sulfonated polyethersulfone resin.

[0015] Preferably, the number of theoretical plates of the precision distillation column is 5 - 20, the operating pressure is negative pressure, the top temperature is 80 - 150 °C, and the reflux ratio is 1 - 20.

[0016] Preferably, the precision distillation column is a stainless steel distillation column lined with polytetrafluoroethylene, and includes a condenser and a reboiler.

[0017] Preferably, the nanofiltration membrane of the nanofiltration device uses polytetrafluoroethylene membrane, polyethersulfone membrane, polyvinylidene fluoride membrane, polyimide membrane, polyamide membrane or other membranes with the same properties with a pore size of 10 - 50 nm.

[0018] Preferably, the top of the light component removal distillation column and the precision distillation column are connected to a recovery column, and the bottom of the recovery column is connected to the lower feed port of the light component removal distillation column.

[0019] Preferably, the number of theoretical plates of the recovery column is 10 - 50, the operating pressure is atmospheric pressure or slightly positive pressure, the top temperature is 80 - 150 °C, and the reflux ratio is 1 - 10.

[0020] Preferably, the recovery column is a common distillation column, made of polished stainless steel, and includes a condenser and a reboiler.

[0021] Preferably, the production system of electronic-grade propylene glycol methyl ether acetate further includes auxiliary equipment such as corresponding pumps and heat exchangers.

[0022] A production method of electronic-grade propylene glycol methyl ether acetate, which is carried out by using the above production system, includes the following steps:

[0023] Industrial-grade propylene glycol methyl ether acetate enters the light-component removal rectification column to remove the light-component impurities in the propylene glycol methyl ether acetate. After the light-component removal, the propylene glycol methyl ether acetate enters the heavy-component removal rectification column to remove the heavy-component impurities in the propylene glycol methyl ether acetate; the propylene glycol methyl ether acetate after the heavy-component removal enters the microfilter to remove particles with a particle size above 0.2 μm; the propylene glycol methyl ether acetate after microfiltration is passed into the anion-cation removal device to remove the metal ions and non-metal ions in the propylene glycol methyl ether acetate; the propylene glycol methyl ether acetate after the anion-cation removal is passed into the precision rectification column to remove the water introduced during the anion-cation exchange process; the propylene glycol methyl ether acetate after precision rectification enters the nanofiltration device to filter out particles above 10 nm, and the electronic-grade propylene glycol methyl ether acetate with a purity of more than 99.99% wt, a metal content of less than 100 ppt, and less than 200 pcs / ml of particles with a particle size above 0.2 μm is obtained after nanofiltration;

[0024] The overhead distillate of the light-component removal rectification column and the overhead distillate of the precision rectification column are passed into the recovery column to recover the propylene glycol methyl ether acetate, and the recovered propylene glycol methyl ether acetate is recycled back to the light-component removal rectification column for further purification.

[0025] The light-component removal rectification column of the present invention removes the light-component impurities in the raw material, such as propylene glycol methyl ether, methyl 2-hydroxyisobutyrate, and water; the heavy-component removal rectification column removes the heavy-component impurities in the raw material, such as 3-methoxybutanol, ethylene glycol butyl ether acetate, 3-methoxybutyl acetate, ethyl 3-ethoxypropionate, glycerol butyrate, etc.; the microfilter removes large particles in the raw material, the anion-cation removal device removes the metal ions and non-metal ions in the propylene glycol methyl ether acetate, the precision rectification column removes the water introduced by the anion-cation removal device, and the nanofiltration device removes the tiny particle impurities in the propylene glycol methyl ether acetate to obtain a product with a purity meeting the requirements of more than 99.99% wt, metal ions less than 100 ppt, and less than 200 pcs / ml of particles with a particle size above 0.2 μm (micrometer); the function of the recovery column is to recover the propylene glycol methyl ether acetate in the overhead distillate of the light-component removal rectification column and the overhead distillate of the precision rectification column and recycle it back to the light-component removal rectification column. It realizes the production of high-purity propylene glycol methyl ether acetate that meets the semiconductor industry standard from industrial-grade propylene glycol methyl ether acetate, and the recovery rate reaches more than 95%.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention provides a method for efficiently and stably producing high-purity electronic-grade propylene glycol methyl ether acetate from industrial-grade propylene glycol methyl ether acetate.

[0028] 2. The present invention provides a method for producing ultra-pure and high-purity propylene glycol methyl ether acetate with high recovery rate, short process flow and low investment by using conventional distillation columns and precision distillation column equipment.

[0029] 3. The present invention provides a method for producing ultra-pure and high-purity propylene glycol methyl ether acetate with high recovery rate, short process flow, good separation effect, strong process continuity, high purity and low impurity content, obtaining a product with a purity of more than 99.99% wt, a metal content of less than 100 ppt, and less than 200 pcs / ml of particulate matter with a particle size of more than 0.2 μm (micrometer), meeting the requirements of the semiconductor industry standard for ultra-pure and high-purity propylene glycol methyl ether acetate.

[0030] 4. The electronic-grade propylene glycol methyl ether acetate obtained by the present invention can be applied to fields such as semiconductor chip manufacturing, display panel manufacturing, and solar cell manufacturing.

[0031] 5. The propylene glycol methyl ether acetate produced by the present invention can meet the production requirements of chips with a size of more than 12 inches.

[0032] 6. The recovery rate of the propylene glycol methyl ether acetate of the present invention reaches more than 95%, making more full use of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the production method of the electronic-grade propylene glycol methyl ether acetate production system of the present invention;

[0034] Figure 2 It is a schematic diagram of the production method of the propylene glycol methyl ether acetate production system of Comparative Example 1;

[0035] In the figure: 1 - light removal distillation column, 2 - heavy removal distillation column, 3 - microfilter, 4 - anion-cation remover, 5 - precision distillation column, 6 - nanofiltration membrane, 7 - recovery column, 8 - industrial-grade propylene glycol methyl ether acetate, 9 - overhead distillate of the light removal distillation column, 10 - propylene glycol methyl ether acetate after light removal, 11 - propylene glycol methyl ether acetate after heavy removal, 12 - heavy components, 13 - propylene glycol methyl ether acetate after microfiltration, 14 - propylene glycol methyl ether acetate after anion-cation removal, 15 - waste water, 16 - propylene glycol methyl ether acetate after precision distillation, 17 - electronic-grade propylene glycol methyl ether acetate, 18 - light components, 19 - recovered propylene glycol methyl ether acetate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and gives the detailed implementation manner and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0037] The propylene glycol methyl ether acetate raw materials used in the following examples and comparative examples are industrial-grade propylene glycol methyl ether acetate. The national standard for industrial-grade propylene glycol methyl ether acetate has a purity of more than 99.5% by mass, a 2-methoxy-1-propanol acetate mass content of less than 0.4%, a water mass content of less than 0.05%, and other impurity mass contents of less than 0.05%. The specific raw material indicators are shown in Table 1 below.

[0038] Table 1 Raw material propylene glycol methyl ether acetate indicators

[0039]

[0040]

[0041] The above table is to illustrate the components contained in the propylene glycol methyl ether acetate raw material and does not limit the applicability of the present invention.

[0042] Example 1

[0043] An electronic-grade propylene glycol methyl ether acetate production system includes a light removal distillation column 1, a heavy removal distillation column 2, a microfilter 3, an anion-cation remover 4, a precision distillation column 5, and a nanofiltration membrane 6 connected in sequence. The light removal distillation column 1 and the precision distillation column 5 are also connected to a recovery column 7.

[0044] When using the system of this example to produce electronic-grade propylene glycol methyl ether acetate, the specific technical solution is as follows:

[0045] a. Light removal distillation. Industrial-grade propylene glycol methyl ether acetate 8 enters the light removal distillation column 1 to remove light component impurities in the raw material, such as propylene glycol methyl ether, methyl 2-hydroxyisobutyrate, and water.

[0046] b. Heavy removal distillation. The bottom material of the light removal distillation column 1 (propylene glycol methyl ether acetate 10 after light removal) enters the heavy removal distillation column 2 to remove heavy component impurities in the raw material, such as 3-methoxybutanol, ethylene glycol butyl ether acetate, 3-methoxybutyl acetate, ethyl 3-ethoxypropionate, glycerol butyrate, etc. The heavy components 12 are discharged from the bottom of the heavy removal distillation column 2.

[0047] c. Microfiltration. The product propylene glycol methyl ether acetate obtained by distillation (propylene glycol methyl ether acetate 11 after heavy removal) passes through the microfilter 3 to filter out particles with a particle size of more than 10 nm (nanometers).

[0048] d. Anion-cation removal. The propylene glycol methyl ether acetate after removing large particles (propylene glycol methyl ether acetate 13 after microfiltration) enters the anion-cation remover 4 to remove metal ions and non-metal ions in the propylene glycol methyl ether acetate.

[0049] e. Precision rectification. The propylene glycol methyl ether acetate from the anion and cation remover 4 (propylene glycol methyl ether acetate 14 after anion and cation removal) enters the precision rectification column 5 to remove the water generated during the anion and cation exchange process.

[0050] f. Nanofiltration. The product propylene glycol methyl ether acetate obtained by rectification (propylene glycol methyl ether acetate 16 after precision rectification) is filtered through the nanofiltration membrane 6 to remove particles larger than 10 nm (nanometers), obtaining an ultra-pure and highly pure propylene glycol methyl ether acetate product (electronic grade propylene glycol methyl ether acetate 17).

[0051] g. Recovery of propylene glycol methyl ether acetate. The mass content of propylene glycol methyl ether acetate in the overhead distillate 9 of the light component removal rectification column and the overhead distillate of the precision rectification column 5 (waste water 15) is above 70%. In order to improve the recovery rate of propylene glycol methyl ether acetate, the overhead distillate 9 of the light component removal rectification column is fed into the recovery column 7 to remove light component impurities. The recovered propylene glycol methyl ether acetate 19 has a mass content above 99% and is refluxed to the lower feed of the light component removal rectification column 1. The light component 18 is discharged from the top of the recovery column 7.

[0052] Example 2

[0053] A production method of ultra-pure and highly pure propylene glycol methyl ether acetate mainly includes: a light component removal rectification column 1, a heavy component removal rectification column 2, a microfilter 3, an anion and cation remover 4, a precision rectification column 5, a nanofiltration membrane 6, a recovery column 7 and corresponding auxiliary equipment such as pumps and heat exchangers. This example provides a production method of ultra-pure and highly pure propylene glycol methyl ether acetate with high recovery rate, short process flow, good separation effect, strong process continuity, high purity and low impurity content, obtaining a product with a purity meeting the requirement of above 99.99% wt, a metal content below 100 ppt, and less than 200 pcs / ml of particles with a particle size above 0.2 μm (micrometer). An ultra-pure and highly pure propylene glycol methyl ether acetate meeting the requirements of the semiconductor industry standard.

[0054] Industrial-grade propylene glycol methyl ether acetate enters the light component removal distillation column 1 to remove light component impurities such as propylene glycol methyl ether, methyl 2-hydroxyisobutyrate, and water in the propylene glycol methyl ether acetate. After the light component removal, the propylene glycol methyl ether acetate enters the heavy component removal distillation column 2 to remove heavy component impurities such as 3-methoxybutanol, ethylene glycol butyl ether acetate, 3-methoxybutyl acetate, ethyl 3-ethoxypropionate, and glycerol butyrate in the propylene glycol methyl ether acetate; the propylene glycol methyl ether acetate after heavy component removal enters the microfilter 3 to remove particles with a particle size above 0.2 μm (micrometer); the propylene glycol methyl ether acetate after microfiltration is passed into the anion-cation remover 4 to remove metal ions and non-metal ions in the propylene glycol methyl ether acetate; the propylene glycol methyl ether acetate after anion-cation removal is passed into the precision distillation column 5 to remove the water introduced during the anion-cation exchange process. To prevent equipment contamination, the precision distillation column 5 uses a stainless steel distillation column lined with polytetrafluoroethylene; the propylene glycol methyl ether acetate after precision distillation enters the nanofiltration membrane 6 to filter out particles above 10 nm (nanometer), and after nanofiltration, an electronic-grade propylene glycol methyl ether acetate product with a purity of more than 99.99% wt, a metal content of less than 100 ppt, and less than 200 pcs / ml of particles with a particle size above 0.2 μm (micrometer) is obtained.

[0055] The overhead distillates of the light component removal distillation column 1 and the precision distillation column 5 contain a relatively high amount of propylene glycol methyl ether acetate, with a mass content of more than 70%. To improve the recovery rate of propylene glycol methyl ether acetate, it is passed into the recovery column 7 to recover propylene glycol methyl ether acetate. The recovered propylene glycol methyl ether acetate has a mass content of more than 99%, but there are a small number of light component impurities, which are recycled back to the lower feed inlet of the light component removal distillation column 1 for further purification.

[0056] Example 3

[0057] Reference Figure 1, Industrial-grade propylene glycol methyl ether acetate 8 enters the light-component removal rectification column 1. The top pressure of the light-component removal rectification column 1 is 0.1 Mpa, the top temperature is 172 °C, the bottom temperature is 175 °C, the number of theoretical plates is 25, and the reflux ratio is 10. Light-component impurities are removed. The propylene glycol methyl ether acetate obtained from the light-component removal rectification column 1 enters the heavy-component removal rectification column 2. The top pressure is -0.1 Mpa, the top temperature is 105 °C, the bottom temperature is 130 °C, the number of theoretical plates is 25, and the reflux ratio is 10. Heavy-component impurities are removed. The propylene glycol methyl ether acetate obtained from the heavy-component removal rectification column 2 passes through the microfilter 3 to remove particles with a particle size above 0.2 μm (micrometer). The microfilter 3 uses a polytetrafluoroethylene membrane with a pore size of 0.2 μm (micrometer) and a uniformity coefficient of 1.1; after microfiltration, it enters the anion-cation removal device 4 to remove metal ions and non-metal ions in the propylene glycol methyl ether acetate. The anion-cation removal device selects ion exchange resins with a pore size of 0.6 mm and below and a particle size uniformity coefficient of 1.1 and below, and selects sulfonic acid group styrene resin; then it enters the precision rectification column 5 to remove the water introduced during the anion-cation exchange process. The top pressure is -0.1 Mpa, the top temperature is 97 °C, the bottom temperature is 135 °C, the number of theoretical plates is 7, and the reflux ratio is 5; the propylene glycol methyl ether acetate obtained from the precision rectification column 5 is filtered by the nanofiltration membrane 6 to remove particles above 10 nm (nanometer). The nanofiltration membrane 6 can use a polyvinylidene fluoride membrane (PVDF) with a pore size of 10 nm (nanometer) and a uniformity coefficient of 1.25. After nanofiltration, an ultra-pure and high-purity propylene glycol methyl ether acetate product is obtained, and the product indicators are shown in Table 2.

[0058] The top distillate of the light-component removal rectification column 1 and the top distillate of the precision rectification column 5 are introduced into the recovery column 7 to recover propylene glycol methyl ether acetate. The top pressure is 0.1 Mpa, the top temperature is 150 °C, the bottom temperature is 171 °C, the number of theoretical plates is 30, and the reflux ratio is 2. The mass purity of the recovered propylene glycol methyl ether acetate is above 99%, and it is returned to the lower part of the light-component removal rectification column 1 for feeding.

[0059] Comparative Example 1

[0060] Reference Figure 2, Industrial-grade propylene glycol methyl ether acetate 8 enters the light-component removal rectification column 1. The top pressure of the light-component removal rectification column 1 is 0.1 Mpa, the top temperature is 172 °C, the bottom temperature is 175 °C, the number of theoretical plates is 25, and the reflux ratio is 10. Light-component impurities are removed. The propylene glycol methyl ether acetate obtained from the light-component removal rectification column 1 enters the heavy-component removal rectification column 2. The top pressure is 0.1 Mpa, the top temperature is 105 °C, the bottom temperature is 130 °C, the number of theoretical plates is 25, and the reflux ratio is 10. Heavy-component impurities are removed. The propylene glycol methyl ether acetate obtained from the heavy-component removal rectification column 2 passes through the microfilter 3 to remove particles with a particle size of more than 0.2 μm (micrometer). The microfilter 3 can use a polytetrafluoroethylene membrane with a pore size of 0.2 μm (micrometer) and a uniformity coefficient of 1.1; after microfiltration, it enters the anion-cation removal device 4 to remove metal ions and non-metal ions in the propylene glycol methyl ether acetate. The anion-cation removal device selects ion exchange resins with a pore size of 0.6 mm or less and a particle size uniformity coefficient of 1.1 or less. It can select sulfonic acid group styrene resin, carboxyl group styrene resin, quaternary amine group styrene resin, perfluorosulfonic acid resin, sulfonated polyethersulfone resin or other ion exchange resins or ion exchange fibers with the same properties; then it enters the precision rectification column 5 to remove the water introduced during the anion-cation exchange process. The top pressure is 0.1 Mpa, the top temperature is 97 °C, the bottom temperature is 135 °C, the number of theoretical plates is 6, and the reflux ratio is 2; the propylene glycol methyl ether acetate obtained from the precision rectification column 5 is filtered through the nanofiltration membrane 6 to remove particles with a size of more than 10 nm (nanometer). The nanofiltration membrane 6 can use a polyvinylidene fluoride membrane (PVDF) with a pore size of 10 nm (nanometer) and a uniformity coefficient of 1.25. After nanofiltration, an ultra-pure and high-purity propylene glycol methyl ether acetate product is obtained, and the product indicators are shown in Table 2.

[0061] The components in titanium tetrachloride of Example 3 and Comparative Example 1 were detected for content. The detection instruments were: for metal elements, boron, silicon, arsenic and other elements in raw materials and products, Agilent ICP-MS / MS 8900 was used; for the impurity content of raw materials and products, Agilent GC-MS gas chromatography was used; and for the particle size analyzer, RION-KS-19AF was used. The results are shown in Table 1-2.

[0062] Table 2 Product Indicators

[0063]

[0064]

[0065] The mass content of the propylene glycol methyl ether acetate product produced by the method of the present invention can reach more than 99.99%, the metal content is below 100 ppt, the silicon content, arsenic content and boron content are below 100 ppt, meeting the requirements of SEMI-C12 (G4) and above standards. Compared with the comparative example, the recovery rate of propylene glycol methyl ether acetate has increased by nearly 10%, making more efficient use of resources.

[0066] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the invention. Obviously, those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. An electronic-grade propylene glycol methyl ether acetate production system, characterized in that, it includes a light removal rectification column (1), a heavy removal rectification column (2), a microfilter (3), an anion-cation remover (4), a precision rectification column (5), and a nanofiltration membrane (6) connected in sequence; The light removal rectification column (1) and the precision rectification column (5) are also connected to a recovery column (7).

2. The electronic-grade propylene glycol methyl ether acetate production system according to claim 1, characterized in that, the light removal rectification column (1) has 10 - 50 theoretical plates, the operating pressure is normal pressure or slightly positive pressure, the top temperature is 160 - 180 °C, and the reflux ratio is 10 - 30.

3. The electronic-grade propylene glycol methyl ether acetate production system according to claim 1, characterized in that, the heavy removal rectification column (2) has 10 - 50 theoretical plates, the operating pressure is negative pressure, the top temperature is 80 - 150 °C, and the reflux ratio is 10 - 30.

4. The electronic-grade propylene glycol methyl ether acetate production system according to claim 1, characterized in that, the filter membrane of the microfilter (3) is one or several of polytetrafluoroethylene membranes, polyethersulfone membranes, polyvinylidene fluoride membranes, polyimide membranes, and polyamide membranes with a pore diameter of 0.1 - 0.5 μm.

5. The electronic-grade propylene glycol methyl ether acetate production system according to claim 1, characterized in that, the anion-cation remover (4) selects ion exchange resins or ion exchange fibers with a pore diameter of 0.6 mm or less and a particle size uniformity coefficient of 1.1 or less.

6. The electronic-grade propylene glycol methyl ether acetate production system according to claim 1, characterized in that, the precision rectification column (5) has 5 - 20 theoretical plates, the operating pressure is negative pressure, the top temperature is 80 - 150 °C, and the reflux ratio is 1 - 20.

7. The electronic-grade propylene glycol methyl ether acetate production system according to claim 1, characterized in that, the nanofiltration membrane of the nanofiltration membrane (6) is made of polytetrafluoroethylene membrane, polyethersulfone membrane, polyvinylidene fluoride membrane, polyimide membrane or polyamide membrane with a pore diameter of 10 - 50 nm.

8. The electronic-grade propylene glycol methyl ether acetate production system according to claim 1, characterized in that, the top of the light removal rectification column (1) and the precision rectification column (5) are connected to the recovery column (7), and the bottom of the recovery column (7) is connected to the lower feed port of the light removal rectification column (1).

9. The electronic-grade propylene glycol methyl ether acetate production system according to claim 1, characterized in that, the recovery column (7) has 10 - 50 theoretical plates, the operating pressure is normal pressure or slightly positive pressure, the top temperature is 80 - 150 °C, and the reflux ratio is 1 - 10.

10. An electronic-grade propylene glycol methyl ether acetate production method, characterized in that, it is carried out using the production system according to any one of claims 1 - 9, and includes the following steps: Industrial-grade propylene glycol methyl ether acetate enters the light-component removal rectification column (1) to remove light-component impurities in the propylene glycol methyl ether acetate. After the removal of light components, the propylene glycol methyl ether acetate enters the heavy-component removal rectification column (2) to remove heavy-component impurities in the propylene glycol methyl ether acetate; the propylene glycol methyl ether acetate after the removal of heavy components enters the microfilter (3) to remove large particles; the propylene glycol methyl ether acetate after microfiltration is fed into the anion-cation remover (4) to remove metal ions and non-metal ions in the propylene glycol methyl ether acetate; the propylene glycol methyl ether acetate after anion-cation removal is fed into the precision rectification column (5) to remove the water introduced during the anion-cation exchange process; the propylene glycol methyl ether acetate after precision rectification enters the nanofiltration membrane to filter out fine particles; The overhead distillate of the light-component removal rectification column (1) and the overhead distillate of the precision rectification column (5) are fed into the recovery column (7) to recover propylene glycol methyl ether acetate, and the recovered propylene glycol methyl ether acetate is recycled back to the light-component removal rectification column (1) for further purification.

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