A production method of electronic chemical catechol

Abstract

The production method of the electronic chemical catechol of the present invention comprises a dissolving step, a microfiltration step, an anion and cation removal step, a flash separation step or a distillation separation step, a nanofiltration step, a crystallization step and a drying step, wherein the dissolving step is to dissolve the industrial-grade catechol with a reagent; the flash separation step is to separate the components of the catechol solution through a flash tank; the distillation separation step is to separate the components of the catechol solution through a first distillation tower and a second distillation tower; the crystallization step is to crystallize the catechol solution after the flash separation step or the catechol solution after nanofiltration through a crystallizer; the drying step is to dry the catechol product after the crystallization step; and a heating step is also included. The preparation method of the present invention has a short process, low energy consumption, good separation effect, strong process continuity, high purity, low impurity content, and the obtained product can meet the requirements of the highest electronic chemical standard SEMIC12 (G4) and above for electronic chemical catechol.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic chemical preparation, and relates to high-purity electronic-grade chemical catechol in the fields of semiconductors, display panels, solar energy, power batteries, medicine, etc., and specifically relates to a production method of electronic chemical catechol. Background Art

[0002] Catechol, also known as catechol, is an organic compound with the chemical formula C 6 H 6 O 2 It is a white crystalline powder and an important chemical intermediate. It can be used as a rubber hardener, electroplating additive, skin preservative and bactericidal agent, hair dye, photographic developer, color photography antioxidant, etc.

[0003] High-purity electronic-grade catechol is usually purified from industrial-grade catechol raw materials. For example, Chinese patent application CN 216472987 U discloses an electronic-grade catechol production device, which processes industrial-grade catechol through melt crystallization, distillation, and ion exchange to improve the purity of catechol. However, the finished particles cannot meet the requirements of SEMI C12 (G4) and SEMI C12 (G5).

[0004] The applicant's Chinese patent application CN114870420A discloses a high-purity electronic grade isopropyl alcohol production device, comprising: industrial grade isopropyl alcohol is subjected to microfiltration, anion and cation removal, dehydration treatment or precision distillation tower, nanofiltration, and the microfiltration and anion and cation removal cannot be dehydrated or distilled at the same time before and after; when there is no dehydration treatment and distillation before microfiltration and anion and cation removal, distillation and nanofiltration or only distillation are performed after microfiltration and anion and cation removal; when microfiltration and anion and cation removal only include anion and cation removal and the dehydration treatment or distillation before them, the anion and cation removal is performed after distillation and nanofiltration or only distillation; Post-nanofiltration; when microfiltration and anion and cation removal only include anion and cation removal and there is no dehydration and distillation in series before, the anion and cation removal is followed by a distillation tower and nanofiltration. The process device and physical parameters of this patent, although electronic-grade products of isopropanol can be obtained, the process parameters of different chemical products, especially different isomers of catechol, have a great influence on the purification results. According to the applicant's test, it cannot be directly used for the preparation of electronic-grade products of crystalline powder chemical products. This application provides a preparation method for electronic-grade products directly used for catechol. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for producing catechol, an electronic chemical.

[0006] One of the purposes of the present invention is to provide a method and device for producing electronic-grade catechol with short process, low energy consumption, good separation effect, strong process continuity, high purity and low impurity content, which can meet the highest standard of electronic chemicals SEMIC12 (G4) and above requirements of electronic chemical catechol.

[0007] The second object of the present invention is to provide a method for producing catechol, an electronic chemical, with low energy consumption, short process and low investment by using a multi-stage flash tank, a conventional distillation tower and / or a dividing wall tower.

[0008] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0009] The object of the present invention is achieved in the following way: industrial-grade catechol, whose catechol mass content is more than 98%, is dissolved in a stirring heater by adding a solvent, and then enters a microfilter to remove large particles in the catechol solution, and then enters an anion and cation removal device, and this process is achieved by ion exchange resin or ion exchange fiber; the catechol solution after the anions and cations are removed enters a separator, and the separator adopts a flash tank, a conventional distillation tower and / or a dividing wall tower, and the dividing wall tower can reduce the number of conventional distillation towers by half, that is, reduce equipment, reduce energy consumption, and shorten the process; the catechol from the separator enters a nanofiltration device, and after removing fine particles, enters a crystallization device for purification, and then is dried to finally obtain a product.

[0010] Industrial-grade catechol and solvent enter a stirring and heating mixer to dissolve into a catechol solution, then enter a microfilter to remove particles larger than 0.2 μm, then enter an anion and cation remover to remove anions and cations in the catechol solution, and after the anions and cations are removed, the catechol solution enters a separator. The number of separators can be increased or decreased by 0-6 according to actual raw materials and product standard requirements. The separator of the present invention is a flash tank, a conventional distillation tower and / or a next-door distillation tower. Under the same separation accuracy requirement, the next-door tower can greatly reduce the number of conventional distillation towers, and can reduce the original 2 conventional distillation towers to 1, the original 4 conventional distillation towers to 2, and the 6 conventional distillation towers to 3, thereby greatly reducing energy consumption and investment. The catechol after the separator is filtered by a nanofilter to remove particles larger than 10 nm, then enters a crystallizer, and is dried to obtain catechol meeting SIMI C12 (G4) standards and above.

[0011] The solvent is selected from one or more of water, methanol, ethanol, n-propanol, isopropanol, acetone, methyl acetate, ethyl acetate, etc., but is not limited to the above.

[0012] Furthermore, a microfilter is used to remove particles with a particle size of 0.2 μm or more, wherein the microfiltration membrane is selected from a polytetrafluoroethylene membrane, a polyethersulfone membrane, a polyvinylidene fluoride membrane (PVDF), a polyimide membrane and a polyamide membrane with a pore size of 0.1-0.5 μm, and a pore size uniformity coefficient of 1.1-1.4;

[0013] The anions and cations in the catechol solution are removed by using an ion exchange resin and / or ion exchange fiber with a particle size of 0.3-0.6 mm, which is one or more of sulfonic acid styrene resin or fiber, carboxyl styrene resin or fiber, quaternary amino styrene resin or fiber, perfluorosulfonic acid resin or fiber, sulfonated polyethersulfone resin or fiber, and the pore size uniformity coefficient is 1.08-1.3;

[0014] Nanofiltration is used to remove particles with a particle size of more than 10nm, and the nanofiltration membrane is selected from one of polytetrafluoroethylene membrane, polyethersulfone membrane, polyvinylidene fluoride membrane (PVDF), polyimide membrane or polyamide membrane with a pore size of 10-50nm, and the pore size uniformity coefficient is 1.05-1.4.

[0015] Furthermore, the microfilter uses a polytetrafluoroethylene membrane with a pore size of 0.2 μm and a uniformity coefficient of 1.25; the ion exchange resin uses a mixed resin with a particle size of 0.6 mm, a uniformity coefficient of 1.1, and a volume ratio of sulfonic acid styrene resin and quaternary amino styrene of 2:1; the nanofilter uses a polytetrafluoroethylene membrane with a pore size of 20 nm and a uniformity coefficient of 1.2;

[0016] The microfilter uses a polyimide membrane with a pore size of 0.4μm and a uniformity coefficient of 1.15; the ion exchange resin uses a mixed resin with a particle size of 0.3mm, a uniformity coefficient of 1.3, and a volume ratio of 3:2 between perfluorosulfonic acid resin and quaternary aminostyrene; the nanofilter uses a polyimide membrane with a pore size of 10nm and a uniformity coefficient of 1.25.

[0017] Furthermore, the solvent used in the catechol solution is one or more of water, methanol, ethanol, n-propanol, isopropanol, acetone, methyl acetate, and ethyl acetate.

[0018] The preparation method removes metal impurities, non-metal impurities and organic impurities in the industrial-grade catechol, including water, other organic impurities, nitrite, sulfate, magnesium ions, manganese ions, iron ions, lead ions, aluminum ions, tin ions, molybdenum ions and gallium ions.

[0019] The preparation method removes metal impurities and non-metal impurities in the industrial-grade catechol, and the metal impurities and non-metal impurities include at least one of the following: a first type, sodium, iron, copper, calcium, potassium, boron and silicon; a second type, sodium, iron, copper, calcium, potassium, boron, silicon, zinc, lead, arsenic, silver and cobalt; a third type, sodium, iron, copper, calcium, lead, potassium, boron and silicon; and a fourth type, sodium, iron, copper, calcium, lead, potassium, boron, silicon, magnesium, zinc, arsenic, aluminum, cadmium, silver, tin, titanium and cobalt. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of an embodiment of the production method and preparation device of the electronic chemical catechol of the present invention.

[0021] Figure 2 It is a schematic diagram of Example 1 of the production method and preparation device of the electronic chemical catechol of the present invention.

[0022] Figure 3 It is a schematic diagram of Example 2 of the production method and preparation device of the electronic chemical catechol of the present invention.

[0023] Figure 4 It is a schematic diagram of Example 3 of the production method and preparation device of the electronic chemical catechol of the present invention.

[0024] Figure 5 It is a schematic diagram of Example 4 of the production method and preparation device of the electronic chemical catechol of the present invention.

[0025] Figure 6 It is a schematic diagram of Example 5 of the production method and preparation device of the electronic chemical catechol of the present invention.

[0026] Figure 7 It is a schematic diagram of Example 6 of the production method and preparation device of the electronic chemical catechol of the present invention.

[0027] Figure 8 These are several forms of the dividing wall tower, A is the middle dividing wall, B is the upper dividing wall, and C is the lower dividing wall.

[0028] Description of reference numerals:

[0029] 1 industrial grade catechol; 2 solvent; 3 stirring and heating mixer; 4 catechol solution; 5 microfilter; 6 catechol after microfiltration; 7 anion and cation remover; 8 catechol after deionization; 9 primary separator; 10 light component; 11 heavy component; 12 catechol after primary separation; 13 nanofilter; 14 catechol after nanofiltration; 15 crystallizer; 17 catechol product after crystallization; 18 dryer; 19 electronic grade catechol product; 20 secondary separator; 21 catechol after secondary separation; 24 tertiary separator DETAILED DESCRIPTION

[0030] The following examples further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and substance of the present invention, modifications or substitutions made to the methods, steps or conditions of the present invention all fall within the scope of the present invention.

[0031] Example

[0032] like Figure 1 As shown, the production device of catechol for electronic chemicals of the present invention includes a stirring and heating mixer, a microfilter, an anion and cation remover, a separator, a nanofiltration filter, a crystallizer, a dryer and corresponding auxiliary equipment such as pumps and heat exchangers, which are connected in series from feeding to discharging. The method of the present invention has a short process, low energy consumption, good separation effect, strong process continuity, high product purity, low impurity content, and obtains a high-purity electronic-grade catechol product that meets the electronic chemical SEMI C12 (G4) standard and above.

[0033] The industrial-grade catechol (1) and the solvent (2) of the present invention enter into a stirring and heating mixer (3) to obtain a catechol solution (4), and then enter into a microfilter (5), which functions to remove particles larger than 0.2 μm (micrometer). The microfilter can be a polytetrafluoroethylene membrane, a polyethersulfone membrane, a polyvinylidene fluoride membrane (PVDF), a polyimide membrane, a polyamide membrane or other membranes of equivalent properties with a pore size of 0.1-0.5 μm.

[0034] After microfiltration, the product enters an anion and cation remover (7) for removing anions and cations from catechol. The anion and cation remover can use ion exchange resin or ion exchange fiber, wherein the ion exchange resin uses a customized functional resin, and the ion exchange fiber uses a customized functional fiber, mainly including one or more of sulfonic acid styrene resin or fiber, carboxyl styrene resin or fiber, quaternary amino styrene resin or fiber, perfluorosulfonic acid resin or fiber, and sulfonated polyethersulfone resin or fiber;

[0035] After the removal of anions and cations, the catechol solution (8) enters the separator (9). The number of separators can be increased or decreased by 0-6 according to the actual raw materials and product standard requirements. The present invention can use one or more of a flash tank, a conventional distillation tower and a distillation tower next to the wall. Under the condition of meeting the same separation degree requirement, the distillation tower next to the wall can greatly reduce the number of conventional distillation towers, such as reducing the original 2 conventional distillation towers to 1, reducing the original 4 conventional distillation towers to 2, and reducing 6 conventional distillation towers to 3 distillation towers, greatly reducing energy consumption and investment. The area ratio of the two sides of the distillation tower next to the wall is 2:8 to 8:2, and the form is a middle distillation wall, an upper distillation wall and a lower distillation wall, but is not limited to the above three types.

[0036] The catechol obtained after separation is filtered through a nanofilter (13) to remove particles larger than 10 nm. The membrane of the nanofilter (13) can be a polytetrafluoroethylene membrane with a pore size of 10-50 nm, a polyethersulfone membrane, a polyvinylidene fluoride membrane (PVDF), a polyimide membrane, a polyamide membrane or other membranes of equivalent properties.

[0037] After nanofiltration, the product enters a crystallizer (15). The crystallizer can be 0-3 levels according to needs. The crystallizer can be a suspension stirring crystallizer, a plate crystallizer or a melt crystallizer, one or a combination of several. The product (17) obtained after crystallization passes through a dryer (18) to obtain catechol that meets the SIMI C12 (G4) standard requirements.

[0038] The catechol raw material of the present invention is industrial-grade catechol, with a catechol mass content of more than 98%, a water content of more than 500ppm, a metal ion of more than 500ppt, an anion of more than 500ppb, and more than 1000 particles larger than 0.2μm / mL. Table 1 shows the components contained in the industrial-grade catechol raw material, which does not limit the applicability of the invention. The catechol products produced by the preparation method and device of the present invention can meet the requirements of SEMI C12 (G4) and above standards.

[0039] Example 1

[0040] refer to Figure 2 The production device of electronic chemical hydroquinone of the present invention comprises a stirring and heating mixer, a microfilter, an anion and cation remover, a flash tank, a nanofilter, a crystallizer and a dryer which are connected in series from feeding to discharging.

[0041] Catechol and solvent methanol enter the stirring and mixing heater (3) at a molar ratio of 0.45, are heated to 50°C and then enter the microfilter, the microfilter uses a polytetrafluoroethylene membrane with a pore size of 0.2μm and a uniformity coefficient of 1.25; the ion exchange resin uses a mixed resin with a particle size of 0.6mm, a uniformity coefficient of 1.1, and a volume ratio of sulfonic acid styrene resin and quaternary amino styrene of 2:1; the separator (9) uses a flash tank with a pressure of 100kPa and a temperature of 70°C; the nanofilter uses a polytetrafluoroethylene membrane with a pore size of 20nm and a uniformity coefficient of 1.2; the crystallizer (15) uses a two-stage falling film crystallization, and the crystallization temperatures are 94°C and 98°C respectively; the drying conditions are 70°C, 70kPa, and 1.5h. A high-purity catechol product higher than the SEMI C12 (G4) standard is obtained, and the product indicators are shown in Table 2.

[0042] Example 2

[0043] refer to Figure 3The production device of the electronic chemical hydroquinone of the present invention comprises a stirring and heating mixer, a microfilter, an anion and cation remover, a conventional distillation tower, a nanofilter, a crystallizer and a dryer which are connected in series from feeding to discharging.

[0044] Catechol and solvent n-propanol enter the stirring and mixing heater (3) at a molar ratio of 0.6, are heated to 60°C and then enter the microfilter, the microfilter uses a polyimide membrane with a pore size of 0.4 μm and a uniformity coefficient of 1.15; the ion exchange resin uses a mixed resin with a particle size of 0.3 mm, a uniformity coefficient of 1.3, and a volume ratio of 3:2 between perfluorosulfonic acid resin and quaternary aminostyrene; the separator (9)(20) uses a conventional distillation tower, wherein the separator (9) is the first distillation tower, and the separator (20) is The first distillation tower has a top pressure of 30 kPa, a top temperature of 73.5 °C, a theoretical plate number of 10, and a reflux ratio of 1.5; the second distillation tower has a top pressure of 3 kPa, a top temperature of 164 °C, a theoretical plate number of 6, and a reflux ratio of 1.5; the nanofilter (13) uses a polyimide membrane with a pore size of 10 nm and a uniformity coefficient of 1.25; the crystallizer (15) uses a first-stage falling film crystallization, and the crystallizer temperature is 96 °C; the dryer setting conditions are 80 °C, 100 kPa, 1.5 h. A high-purity catechol product higher than the SEMI C12 (G4) standard is obtained, and the product indicators are shown in Table 2.

[0045] Example 3

[0046] refer to Figure 4 The production device of electronic chemical hydroquinone of the present invention comprises a stirring and heating mixer, a microfilter, an anion and cation remover, a nanofilter, a dividing wall distillation tower, a crystallizer and a dryer connected in series from feeding to discharging. The dividing wall distillation tower adopts a C-type dividing wall tower, a condenser and two reboilers.

[0047] Catechol and solvent isopropanol enter the stirring and mixing heater (3) at a molar ratio of 0.45, are heated to 45°C and then enter the microfilter, the microfilter adopts a polyamide membrane with a pore size of 0.2μm and a uniformity coefficient of 1.35; the ion exchange resin adopts a mixed resin with a particle size of 0.5mm, a uniformity coefficient of 1.12, and a volume ratio of sulfonic acid styrene resin and quaternary amino styrene of 3:1; the nanofilter (13) adopts a polyvinylidene fluoride (PVDF) membrane with a pore size of 30nm and a uniformity coefficient of 1.1; the separator (9) adopts a C-type dividing wall tower, with a two-side area ratio of 6:4, a tower top pressure of 10kPa, a tower top temperature of 39.5°C, a theoretical plate number of 18, and a reflux ratio of 2; the crystallizer (15) adopts a single-stage plate crystallization, and the crystallization temperature is 95°C; the dryer setting conditions are 100°C, 100kPa, 30min. The obtained product is a high-purity catechol product that exceeds the SEMI C12 (G4) standard. The product indicators are shown in Table 3.

[0048] Example 4

[0049] refer to Figure 5 The production device of electronic chemical hydroquinone of the present invention comprises a stirring and heating mixer, a microfilter, an anion and cation remover, a nanofilter, a crystallizer and a dryer which are connected in series from feeding to discharging.

[0050] Catechol and solvent acetone enter the stirring and mixing heater (3) at a molar ratio of 0.5, are heated to 40°C and then enter the microfilter, which uses a polyimide membrane with a pore size of 0.1μm and a uniformity coefficient of 1.4; the ion exchange resin uses a mixed resin with a particle size of 0.6mm, a uniformity coefficient of 1.08, and a volume ratio of 3:1 between perfluorosulfonic acid resin and quaternary aminostyrene; the nanofilter (13) uses a polyvinylidene fluoride (PVDF) membrane with a pore size of 10nm and a uniformity coefficient of 1.25; the crystallization (15) uses a three-stage crystallization, which is a suspended stirring crystallizer, a plate crystallizer and a falling film crystallizer, and the crystallization temperatures are 10°C, 70°C, and 93°C respectively; the conditions of the dryer are 80°C, 80kPa, and 1h. A high-purity catechol product higher than the SEMI C12 (G4) standard is obtained, and the product indicators are shown in Table 3.

[0051] Example 5

[0052] refer to Figure 6 The production device of electronic chemical hydroquinone of the present invention comprises a stirring and heating mixer, an anion and cation remover, a nanofilter, a flash tank, a crystallizer and a dryer which are connected in series from feeding to discharging.

[0053] Catechol and solvent methyl acetate enter the stirring and mixing heater (3) at a molar ratio of 0.45, are heated to 50°C and then enter the ion exchange resin; the ion exchange resin uses a mixed resin with a particle size of 0.5 mm, a uniformity coefficient of 1.18, and a volume ratio of 3:2 between phosphate-based styrene resin and quaternary amino styrene; the nanofilter uses a polyamide membrane with a pore size of 50 nm and a uniformity coefficient of 1.05; the separator (9) uses a flash tank with a pressure of 400 kPa and a temperature of 130°C; the crystallization uses a first-stage plate crystallization with a crystallization temperature of 96°C; the dryer setting conditions are 90°C, 90 kPa, and 45 minutes. A high-purity catechol product higher than the SEMI C12 (G4) standard is obtained, and the product indicators are shown in Table 3.

[0054] Example 6

[0055] refer to Figure 7 The production device of electronic chemical hydroquinone of the present invention comprises a stirring and heating mixer, an anion and cation remover, a flash tank, a nanofilter, a crystallizer and a dryer which are connected in series from feeding to discharging.

[0056] Catechol and solvent ethyl acetate enter the stirring and mixing heater (3) at a molar ratio of 0.57, are heated to 60°C and then enter the ion exchange resin; the ion exchange resin uses a mixed resin with a particle size of 0.4mm, a uniformity coefficient of 1.27, and a volume ratio of 3:2 between perfluorosulfonic acid resin and quaternary aminostyrene; the separator (9) uses a flash tank with a pressure of 200kPa and a temperature of 135°C; the nanofilter uses a polytetrafluoroethylene membrane with a pore size of 50nm and a uniformity coefficient of 1.06; the crystallization uses a first-level falling film crystallization, and the crystallization temperature is 95°C; the dryer setting conditions are 60°C, 50kPa, and 2h. A high-purity catechol product higher than the SEMI C12 (G4) standard is obtained, and the product indicators are shown in Table 3.

[0057] Comparative Example 1

[0058] The raw materials and process are the same as those in Example 3. Figure 4 , the difference from Example 3 is that the particle size uniformity coefficient of the ion exchange resin used in the ion exchange remover is changed to 1.4. The product indicators are shown in Table 4. Sodium, iron, copper, calcium, potassium, boron and silicon cannot meet the requirements of SEMI C12 (G4); sodium, iron, copper, calcium, potassium, boron, silicon, zinc, lead, arsenic, silver and cobalt cannot meet the requirements of SEMI C12 (G5).

[0059] Comparative Example 2

[0060] The raw materials and process are the same as those in Example 3. Figure 4 , the difference from Example 3 is that the particle size of the ion exchange resin used in the ion exchange remover is changed to 0.7 mm. The product indicators are shown in Table 4. Sodium, iron, copper, calcium, lead, potassium, boron and silicon cannot meet the SEMI C12 (G4) requirements; sodium, iron, copper, calcium, lead, potassium, boron, silicon, magnesium, zinc, arsenic, aluminum, cadmium, silver, tin, titanium and cobalt cannot meet the G5 requirements.

[0061] Comparative Example 5

[0062] The feed and operating conditions of this comparative example are exactly the same as those of Example 6. Figure 7 The difference is that the crystallizer is changed from primary to secondary, and the product indicators are shown in Table 4. The product purity cannot meet the SEMI C12 (G4) requirements.

[0063] Comparative Example 6

[0064] The preparation process of electronic chemical hydroquinone is as follows: industrial-grade hydroquinone enters a melt crystallizer, and the discharge end pipe of the industrial-grade hydroquinone feed pipeline is connected to the feed end of the melt crystallizer; a melt crystallization residual liquid tank and a melt crystallization finished product tank, and the feed end pipes of the melt crystallization residual liquid tank and the melt crystallization finished product tank are connected to the discharge end of the melt crystallizer; a hydroquinone quartz distillation tower, the feed end of the hydroquinone quartz distillation tower is connected to the discharge end pipe of the melt crystallization residual liquid tank, and the discharge end is connected to the feed end pipe of the melt crystallizer, and a hydroquinone tower top condenser is arranged on the hydroquinone quartz distillation tower; an ion exchange column, an ion exchange resin layer is provided in the ion exchange column, the feed end of the ion exchange column is connected to the discharge end pipe of the melt crystallization finished product tank, and the waste liquid discharge end of the ion exchange column is connected to the feed end pipe of the hydroquinone quartz distillation tower; an industrial-grade hydroquinone discharge pipeline, and the feed end of the industrial-grade hydroquinone discharge pipeline is connected to the discharge end pipe of the ion exchange column. The product specifications are shown in Table 4. The particles cannot meet the requirements of SEMI C12 (G4) and SEMI C12 (G5).

[0065] Test Example 1

[0066] The content of the components in the electronic chemical catechol of Examples 1-8 and Comparative Examples 1, 2, 5, and 6 was detected by using the following instruments: PerkinElmer ICP-OES / Avio550MAX for raw material cations, Agilent ICP-MS / MS8900 for product cations, Swiss Metrohm 940 ion chromatograph for raw material and product anions, 851 Coulometric Karl Fischer water analyzer for raw material and product water content, Agilent GC-MS gas chromatograph for raw material and product organic impurities, and RION-KS-42AF for particle size analyzer. The results are shown in Tables 1-4, and the raw materials in Table 1 refer to industrial-grade catechol.

[0067] Table 1 Industrial catechol raw material indicators

[0068]

[0069] Table 2 Product indicators obtained by the production method and production device of Example 1-2 of the present invention

[0070]

[0071]

[0072] Table 3 Product indicators obtained by the production method and production device of Examples 3-6 of the present invention

[0073]

[0074]

[0075]

[0076] Table 4 Product indicators obtained by comparative examples 1, 2, 5, and 6 of the present invention

[0077]

[0078]

[0079]

[0080] Table 5 Contents of metal impurities and non-metal impurities in catechol, an electronic chemical

[0081]

[0082] Although the present invention has been described in detail above by general description, specific implementation methods and experiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A method for producing catechol, an electronic chemical, comprising a dissolving step, a microfiltration step, an anion and cation removal step, a rectification and separation step, a nanofiltration step, a crystallization step and a drying step, characterized in that: Including any of the following processes: The first step is sequentially composed of a dissolution step, a microfiltration step, an anion and cation removal step, a flash separation step, a nanofiltration step, a crystallization step and a drying step; The second step is sequentially composed of a dissolution step, a microfiltration step, an anion and cation removal step, a rectification separation step, a nanofiltration step, a crystallization step and a drying step; The third step is sequentially composed of a dissolution step, a microfiltration step, an anion and cation removal step, a nanofiltration step, a rectification and separation step, a crystallization step and a drying step; The fourth step is sequentially composed of a dissolution step, a microfiltration step, an anion and cation removal step, a nanofiltration step, a crystallization step and a drying step; The fifth step is sequentially composed of a dissolution step, an anion and cation removal step, a nanofiltration step, a flash separation step, a crystallization step and a drying step; The sixth step is sequentially composed of a dissolving step, an anion and cation removal step, a flash separation step, a nanofiltration step, a crystallization step and a drying step; The dissolving step is to dissolve industrial-grade catechol with a reagent to obtain a catechol solution, wherein the reagent is selected from one or more of methanol and n-propanol; The flash separation step is to separate the components of the catechol solution through a flash tank, and the pressure of the flash separation step is 100 kPa and the temperature is 70° C.; The distillation separation step is to separate the components of the catechol solution through a first distillation tower and a second distillation tower, wherein the first distillation tower has a top pressure of 30 kPa, a top temperature of 73.5°C, a theoretical plate number of 10, and a reflux ratio of 1.5, and the second distillation tower has a top pressure of 3 kPa, a top temperature of 164°C, a theoretical plate number of 6, and a reflux ratio of 1.5; The crystallization step crystallizes the catechol solution through a crystallizer, the crystallization step adopts a primary crystallization process, the crystallization temperature is 95-96°C, or the crystallization step adopts a secondary crystallization process, the primary crystallization temperature is 93-94°C, the secondary crystallization temperature is 97-98°C, or the crystallization step adopts a tertiary crystallization process, the primary crystallization temperature is 10-15°C, the secondary crystallization temperature is 65-75°C, and the tertiary crystallization temperature is 93-95°C; The drying step is to dry the catechol product after the crystallization step at a temperature of 70-80° C. and a pressure of 70-100 KPa for 1.5 hours; The method further comprises a heating step of heating the catechol solution after the dissolving step to 50-60°C.

2. The production method according to claim 1, characterized in that The microfiltration steps of the first, second, third and fourth steps are to remove particles with a particle size of 0.2 μm or more, using a microfilter, wherein the microfiltration membrane is selected from a polytetrafluoroethylene membrane, a polyethersulfone membrane, a polyvinylidene fluoride membrane, a polyimide membrane and a polyamide membrane with a pore size of 0.1-0.5 μm, and the pore size uniformity coefficient is 1.1-1.4; The anion and cation removal step of each process uses an ion exchange resin and / or ion exchange fiber with a particle size of 0.3-0.6 mm to remove anions and cations in the catechol solution, wherein the ion exchange resin and / or ion exchange fiber is one or more of sulfonic acid styrene resin or fiber, carboxyl styrene resin or fiber, quaternary amino styrene resin or fiber, perfluorosulfonic acid resin or fiber, sulfonated polyethersulfone resin or fiber, and has a pore size uniformity coefficient of 1.08-1.3; The nanofiltration step of each process removes particles with a particle size of 10 nm or more, and the nanofilter membrane is selected from one of polytetrafluoroethylene membrane, polyethersulfone membrane, polyvinylidene fluoride membrane, polyimide membrane or polyamide membrane with a pore size of 10-50 nm, and the pore size uniformity coefficient is 1.05-1.

4.

3. The production method according to claim 2, characterized in that: The microfilter of the first process uses a polytetrafluoroethylene membrane with a pore size of 0.2μm and a uniformity coefficient of 1.25; the ion exchange resin uses a mixed resin with a particle size of 0.6mm, a uniformity coefficient of 1.1, and a volume ratio of sulfonic acid styrene resin and quaternary amino styrene of 2:1; the nanofilter uses a polytetrafluoroethylene membrane with a pore size of 20nm and a uniformity coefficient of 1.2; The microfilter of the second process uses a polyimide membrane with a pore size of 0.4μm and a uniformity coefficient of 1.15; the ion exchange resin uses a mixed resin with a particle size of 0.3mm, a uniformity coefficient of 1.3, and a volume ratio of 3:2 between perfluorosulfonic acid resin and quaternary aminostyrene; the nanofilter uses a polyimide membrane with a pore size of 10nm and a uniformity coefficient of 1.

25.

4. The production method according to claim 3, characterized in that: The contents of various impurities in the electronic chemical catechol are shown in the following table:

5. The production method according to claim 1, characterized in that: The contents of various impurities in the industrial grade catechol are shown in the following table:

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