A process for the preparation of a triglycidyl-p-aminophenol condensate

Abstract

The application relates to the technical field of organic synthesis, and discloses a condensation preparation method of triglycidyl p-aminophenol, which comprises S1, a low-temperature ring-opening addition reaction, S2, a gradient ring-closing reaction, S3, raw material recovery, S4, extraction and refined water washing, and S5, desolventizing to obtain a finished product. The condensation preparation method of the triglycidyl p-aminophenol is an integrated process design of a composite solvent system, low-temperature segmented ring-opening, phase transfer catalysis reinforced mass transfer, gradient controlled alkaline ring-closing, nitrogen protection against oxidation, negative pressure raw material recovery and simplified low-salt water washing, which can inhibit side reactions from the reaction mechanism level, improve product quality and yield, reduce raw material consumption and three-waste emissions, meet the requirements of laboratory small tests, pilot tests and industrial large-scale continuous production, set a special vacuum distillation process to recover epichlorohydrin, has high recovery rate, and the recovered raw material can be directly recycled and applied; compared with a traditional process, the total raw material consumption is effectively reduced, and the raw material cost is significantly reduced.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, specifically to a method for preparing triglycidyl-p-aminophenol by condensation. Background Technology

[0002] The mainstream process for synthesizing triglycidyl-p-aminophenol in industry and laboratories involves a two-step continuous reaction of p-aminophenol as the parent material with epichlorohydrin under strongly alkaline conditions, via nucleophilic ring-opening addition followed by intramolecular cyclization and ring-closure. While the overall reaction route is mature, the existing process suffers from several unavoidable technical defects: numerous side reactions, low product purity and dark color; high raw material consumption and low recovery rate; poor mass transfer efficiency and long reaction cycle; cumbersome post-processing steps and serious pollution from waste; and poor process stability with large batch-to-batch variations.

[0003] To address the aforementioned issues, various improvement schemes have emerged in the industry, such as adding a single catalyst and adjusting the reaction temperature. However, none of these schemes optimize the entire process from the perspectives of staged reaction control, gradient addition of alkali, enhanced two-phase mass transfer, raw material recovery, and simplified post-processing, resulting in limited overall improvement. Therefore, developing a method for preparing triglycidyl-p-aminophenol that minimizes side reactions, produces high-purity products with light color, high raw material utilization, low emissions of waste, and is stable and easily scaled up is a pressing technical problem in this field. To this end, this application proposes a condensation preparation method for triglycidyl-p-aminophenol. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for the condensation preparation of triglycidyl p-aminophenol, which has the advantages of improving product quality and yield while reducing raw material consumption and waste emissions. It overcomes the defects of existing synthesis processes, such as numerous side reactions, dark product color, low purity, serious raw material waste, large wastewater production, long reaction cycle, and poor batch stability.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing triglycidyl-p-aminophenol by condensation, comprising the following steps: S1. Low-temperature ring-opening addition reaction: Epichlorohydrin and a composite low-carbon alcohol solvent are added to the reaction apparatus and stirred at room temperature until homogeneous. The system temperature is controlled at 25-40℃. p-Aminophenol is added in batches over 2-3 hours. The molar ratio of p-aminophenol to epichlorohydrin is 1:9-12. After the addition is completed, the temperature is raised to 45-52℃ and stirred for 3-5 hours to obtain a mixture containing tris(3-chloro-2-hydroxypropyl)p-aminophenol intermediate. S2, Gradient ring-closing reaction: The mixture obtained in step S1 is cooled to 40-48℃, and a sodium hydroxide aqueous solution with a mass fraction of 40%-50% is added dropwise in 2-4 batches to carry out the ring-closing reaction; the total amount of sodium hydroxide is 3.8-4.5 times the amount of p-aminophenol; after each batch of alkali solution is added, the temperature is maintained for 0.5-1h. After all the alkali solution is added, the temperature is raised to 50-58℃ and the ring-closing reaction is continued for 2-3h to obtain a crude reaction solution of triglycidyl p-aminophenol; S3. Raw material recovery: After the closed-loop reaction is completed, the crude reaction liquid is subjected to vacuum distillation to recover the epichlorohydrin that did not participate in the reaction. The recovered epichlorohydrin is directly reused in step S1. S4. Extraction and purification washing: Add organic solvent to the distillation residue for extraction, allow to stand and separate the layers to obtain the organic phase; wash the organic phase 1-2 times with a low-salt solution, and then wash with deionized water until the pH of the system is 6.5-7.5. S5. Desolventizing to obtain the finished product: The washed organic phase is subjected to reduced pressure to remove the extraction solvent. After cooling, a pale yellow to light amber transparent viscous liquid is obtained, which is the triglycidyl-p-aminophenol product.

[0006] Preferably, in step S1, the composite low-carbon alcohol solvent is any one or a mixture of two of methanol, ethanol, and isopropanol, and the mass ratio of epichlorohydrin to the composite low-carbon alcohol solvent is 1:0.2 to 0.5.

[0007] Preferably, a phase transfer catalyst is added in step S1 or step S2. The phase transfer catalyst is a quaternary ammonium salt compound, and the amount added is 0.1% to 0.5% of the mass of p-aminophenol.

[0008] Preferably, the quaternary ammonium salt phase transfer catalyst is any one of tetraethylammonium bromide, benzyltriethylammonium chloride, and tetrabutylammonium chloride.

[0009] Preferably, the vacuum distillation process parameters in step S3 are: system temperature 60-70℃, vacuum degree -0.08MPa to -0.095MPa, and epichlorohydrin recovery rate ≥92%.

[0010] Preferably, the extraction organic solvent in step S4 is any one of toluene, xylene, and methyl isobutyl ketone, and the volume ratio of the extraction solvent to the distillation residue is 0.8:1 to 1.2:1.

[0011] Preferably, the low-salt solution in step S4 is a sodium chloride aqueous solution with a mass fraction of 5% to 10%.

[0012] Preferably, in step S5, the vacuum degree of desolventizing is -0.09MPa to -0.098MPa, the temperature is 75 to 90°C, and desolventizing continues until no solvent distills out of the system.

[0013] The relevant procedures are implemented as follows: Low-temperature ring-opening addition reaction: Select a four-necked reaction flask or enamel-lined reactor equipped with a stirring device, temperature measuring device, dropping funnel, nitrogen port, and reflux condenser.

[0014] Add epichlorohydrin and a complex low-carbon alcohol solvent in the specified proportions, start stirring, and control the speed at 200-400 r / min. Mix at room temperature for 5-10 minutes until the system is homogeneous. Stabilize the system at 25-40℃ using a temperature control system. Add solid p-aminophenol in batches over 2-3 hours, ensuring a uniform amount of material added each time to avoid localized material accumulation.

[0015] The material ratios are strictly controlled: the molar ratio of p-aminophenol to epichlorohydrin is 1:9–12; the mass ratio of epichlorohydrin to the composite low-carbon alcohol solvent is 1:0.2–0.5. The composite low-carbon alcohol is selected from one or two of methanol, ethanol, and isopropanol, and its function is to improve the solubility of p-aminophenol in the organic phase and further enhance mass transfer.

[0016] After all solid raw materials are fed in, the temperature is gradually raised to 45-52°C, and the mixture is stirred and kept at this temperature for 3-5 hours to complete the ring-opening addition and obtain the intermediate mixture.

[0017] Gradient-controlled alkali closed-loop reaction: After the ring-opening system is cooled to 40–48°C, an alkaline ring-closing agent is added dropwise in portions. The ring-closing agent is a 40%–50% sodium hydroxide aqueous solution, and the total amount of sodium hydroxide is 3.8–4.5 times the amount of p-aminophenol.

[0018] The alkali solution is added dropwise in 2-4 batches, with each batch added over a time of 15-25 minutes. After each batch is added, the mixture is kept warm and stirred for 0.5-1 hour to ensure complete acid-base reaction and prevent excessively high local alkali concentrations. After all the alkali solution has been added, the temperature is raised to 50-58°C, and the reaction is continued at this temperature for 2-3 hours to complete intramolecular cyclization, yielding a crude triglycidyl-p-aminophenol reaction solution.

[0019] As a preferred option, a quaternary ammonium salt phase transfer catalyst is added in this step or the ring-opening step, with the catalyst addition amount being 0.1% to 0.5% of the mass of p-aminophenol; the catalyst can be tetraethylammonium bromide, benzyltriethylammonium chloride, or tetrabutylammonium chloride. The catalyst can significantly improve the oil-water two-phase mass transfer efficiency and shorten the overall reaction time.

[0020] Recovery of epichlorohydrin by vacuum distillation: After the closed-loop reaction is complete, turn off the nitrogen protection (maintain a slight negative pressure) and start the vacuum distillation system. Control the distillation temperature at 60-70℃ and maintain the system vacuum at -0.08MPa to -0.095MPa to recover unreacted free epichlorohydrin from the system.

[0021] The distilled epichlorohydrin is collected by condensation, and after purity testing, it is directly recycled for the next batch of ring-opening addition reaction. The epichlorohydrin recovery rate in this process can reach more than 92%, which greatly reduces raw material consumption and VOC emissions. After distillation until no obvious fraction flows out, distillation is stopped and the residual liquid in the kettle is collected.

[0022] Extraction and low-salt water washing refining: Add an extraction organic solvent to the distillation residue. The extraction solvent can be any one of toluene, xylene, or methyl isobutyl ketone, with a volume ratio of extraction solvent to residue of 0.8:1 to 1.2:1. Stir and extract at room temperature for 15 to 30 minutes, then allow to stand for 20 to 40 minutes to separate the lower aqueous phase from the upper organic phase.

[0023] The organic phase is preferentially washed 1-2 times with a 5%–10% sodium chloride low-salt solution to reduce product dissolution loss in the aqueous phase due to salting-out effect. Then, it is washed multiple times with deionized water until the pH of the lower organic phase wash water stabilizes at 6.5–7.5, ensuring complete removal of residual alkali and salts from the system. Compared to traditional multiple washes with pure water, low-salt washing can reduce the number of washes by more than 50%, significantly reducing wastewater production.

[0024] The product was obtained by desolventizing under reduced pressure. After washing, the organic phase is transferred to a solvent removal device for desolventizing under reduced pressure. Process parameters: vacuum degree -0.09MPa to -0.098MPa, temperature 75 to 90℃, continuous distillation until no solvent is distilled off. After solvent removal, the mixture is allowed to cool naturally to room temperature, yielding a pale yellow to light amber transparent viscous liquid, which is the industrial-grade triglycidyl-p-aminophenol product.

[0025] Secondary refining: If the product is used in ultra-high purity fields such as optical materials and high-end electronic packaging, the industrial-grade finished product can be further refined: Option 1: Short-path molecular distillation, distillation temperature 90~110℃, vacuum degree ≤-0.099MPa, to remove trace oligomers and colored impurities; Option 2: Recrystallize using a mixed solvent of ethanol and toluene, followed by low-temperature crystallization, filtration, and low-temperature solvent removal.

[0026] After secondary purification, the product has a liquid chromatography purity of ≥99%, and its color becomes even lighter. Compared with the prior art, the present invention provides a method for preparing triglycidyl-p-aminophenol by condensation, which has the following beneficial effects: 1. The condensation preparation method of triglycidyl-p-aminophenol utilizes an integrated process design that incorporates a composite solvent system, low-temperature segmented ring-opening, phase transfer catalysis to enhance mass transfer, gradient alkali control for ring closure, nitrogen anti-oxidation protection, negative pressure raw material recovery, and simplified low-salt water washing. This approach suppresses side reactions at the reaction mechanism level, improves product quality and yield, and simultaneously reduces raw material consumption and waste emissions, thus meeting the needs of laboratory-scale, pilot-scale, and large-scale continuous industrial production.

[0027] 2. The condensation preparation method of triglycidyl-p-aminophenol includes a dedicated vacuum distillation process to recover epichlorohydrin, which has a high recovery rate and the recovered raw materials can be directly recycled. The total raw material consumption is effectively reduced compared with the traditional process, significantly reducing the cost of raw materials. Attached Figure Description

[0028] Figure 1 This is a diagram illustrating the preparation method of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] A method for preparing triglycidyl-p-aminophenol by condensation includes the following steps: S1. Low-temperature ring-opening addition reaction: Epichlorohydrin and a composite low-carbon alcohol solvent are added to the reaction apparatus and stirred at room temperature until homogeneous. The system temperature is controlled at 25-40℃. p-Aminophenol is added in batches over 2-3 hours. The molar ratio of p-aminophenol to epichlorohydrin is 1:9-12. After the addition is completed, the temperature is raised to 45-52℃ and stirred for 3-5 hours to obtain a mixture containing tris(3-chloro-2-hydroxypropyl)p-aminophenol intermediate. S2, Gradient ring-closing reaction: The mixture obtained in step S1 is cooled to 40-48℃, and a sodium hydroxide aqueous solution with a mass fraction of 40%-50% is added dropwise in 2-4 batches to carry out the ring-closing reaction; the total amount of sodium hydroxide is 3.8-4.5 times the amount of p-aminophenol; after each batch of alkali solution is added, the temperature is maintained for 0.5-1h. After all the alkali solution is added, the temperature is raised to 50-58℃ and the ring-closing reaction is continued for 2-3h to obtain a crude reaction solution of triglycidyl p-aminophenol; S3. Raw material recovery: After the closed-loop reaction is completed, the crude reaction liquid is subjected to vacuum distillation to recover the epichlorohydrin that did not participate in the reaction. The recovered epichlorohydrin is directly reused in step S1. S4. Extraction and purification washing: Add organic solvent to the distillation residue for extraction, allow to stand and separate the layers to obtain the organic phase; wash the organic phase 1-2 times with a low-salt solution, and then wash with deionized water until the pH of the system is 6.5-7.5. S5. Desolventizing to obtain the finished product: The washed organic phase is subjected to reduced pressure to remove the extraction solvent. After cooling, a pale yellow to light amber transparent viscous liquid is obtained, which is the triglycidyl-p-aminophenol product.

[0031] Furthermore, in step S1, the composite low-carbon alcohol solvent is any one or a mixture of two of methanol, ethanol, and isopropanol, and the mass ratio of epichlorohydrin to the composite low-carbon alcohol solvent is 1:0.2 to 0.5.

[0032] Furthermore, a phase transfer catalyst is added in step S1 or step S2. The phase transfer catalyst is a quaternary ammonium salt compound, and the amount added is 0.1% to 0.5% of the mass of p-aminophenol.

[0033] Furthermore, the quaternary ammonium salt phase transfer catalyst is any one of tetraethylammonium bromide, benzyltriethylammonium chloride, and tetrabutylammonium chloride.

[0034] Furthermore, the vacuum distillation process parameters in step S3 are: system temperature 60-70℃, vacuum degree -0.08MPa to -0.095MPa, and epichlorohydrin recovery rate ≥92%.

[0035] Furthermore, in step S4, the extraction organic solvent is any one of toluene, xylene, and methyl isobutyl ketone, and the volume ratio of the extraction solvent to the distillation residue is 0.8:1 to 1.2:1.

[0036] Furthermore, the low-salt solution in step S4 is a sodium chloride aqueous solution with a mass fraction of 5% to 10%.

[0037] Furthermore, in step S5, the vacuum degree of desolventizing is -0.09MPa to -0.098MPa, and the temperature is 75 to 90℃, until no solvent distills out of the system.

[0038] Example 1: Basic process, without catalyst A 1000mL four-necked flask was used, equipped with a stirring, reflux condenser, temperature measuring, and nitrogen introduction device.

[0039] 1. Ring-opening addition: Add 111 g (1.2 mol) of epichlorohydrin and 33 g of ethanol, start stirring (300 r / min), purge with nitrogen (flow rate 8 L / h), and maintain the system temperature at 30 °C. Add 10.9 g (0.1 mol) of p-aminophenol in portions over 2.5 h; after the addition is complete, raise the temperature to 50 °C and maintain the reaction temperature for 4 h to obtain an intermediate mixture.

[0040] 2. Gradient closed-loop reaction: Cool down to 45℃, add 32g of 50% sodium hydroxide aqueous solution (containing 0.4mol NaOH) in 3 batches, each batch for 20min, and keep warm for 40min after each addition; after all the alkali solution has been added, raise the temperature to 55℃ and allow the closed-loop reaction to proceed for 2.5h.

[0041] 3. Raw material recovery: vacuum distillation, temperature 65℃, vacuum degree -0.09MPa, 98.2g of epichlorohydrin was recovered, with a recovery rate of 93.1%.

[0042] 4. Extraction and washing: Add 100 mL of toluene to the residual liquid in the vessel, stir and extract for 20 min, and let stand to separate the layers; wash the organic phase once with 8% sodium chloride aqueous solution, and then wash with deionized water until pH=7.0.

[0043] 5. Solution removal product: The organic phase was desolvated under reduced pressure (temperature 82℃, vacuum degree -0.095MPa), and after cooling, 27.5g of product was obtained.

[0044] Test results: Yield 89.0%, HPLC purity 97.8%, epoxy equivalent 94 g / eq, APHA color 140.

[0045] Example 2: Addition of a phase transfer catalyst, preferred scheme The raw material ratio and operation steps are exactly the same as in Example 1, except that 0.055 g of benzyltriethylammonium chloride (0.5% of the mass of p-aminophenol) is added during the ring-opening reaction stage.

[0046] The overall reaction time was shortened, with the time to open the circuit and maintain a constant temperature reduced from 4 hours to 3.2 hours; the final product yielded 28.2g.

[0047] Test results: yield 91.2%, HPLC purity 98.3%, epoxy equivalent 93 g / eq, APHA color 120.

[0048] Example 3: Isopropanol composite solvent + tetraethylammonium bromide catalyst 1. Materials: 0.1 mol p-aminophenol, 1.1 mol epichlorohydrin, epichlorohydrin:isopropanol = 1:0.3 (mass ratio); 0.022 g tetraethylammonium bromide was added (addition amount 0.2%).

[0049] 2. Process parameters: Open-loop temperature 35℃, feeding time 2h, holding temperature 48℃, reaction time 3.5h; alkali solution is added in two batches, closed loop at 45℃, total closed loop time 2.2h; nitrogen flow rate 10L / h.

[0050] 3. Post-treatment: Xylene was used as the extractant, and the sample was washed once with 6% sodium chloride solution.

[0051] Test results: Product weight 27.9g, yield 90.1%, purity 98.1%, APHA color 125, epoxy equivalent 95g / eq.

[0052] Example 4 (Ultra-high purity product, purified by double molecular distillation) The product obtained in Example 2 was purified by short-path molecular distillation at a distillation temperature of 100°C and a vacuum of -0.099 MPa.

[0053] Post-refining testing: HPLC purity 99.2%, APHA color 85, epoxy equivalent 92g / eq, suitable for optical and high-end electronic fields.

[0054] Comparative Example 1: Traditional one-step alkali addition process, current mainstream technology Raw material ratio: 0.1 mol p-aminophenol, 1.5 mol epichlorohydrin (molar ratio 1:15), no solvent, no catalyst, no nitrogen protection, and no raw material recovery.

[0055] Procedure: Add all epichlorohydrin at once, add p-aminophenol at 40°C, raise the temperature to 62°C, add 50% NaOH aqueous solution at once, and react continuously at high temperature for 6.5 hours. After the reaction is completed, wash with pure water 5 times and remove solvent to obtain the product.

[0056] Test results: Product yield 24.3g, yield 78.7%, HPLC purity 94.2%, epoxy equivalent 106g / eq, APHA color 360, wastewater production 2.1 times that of Example 2.

[0057] Comparative Example 2: High-temperature reaction + single alkali addition, an improvement on the traditional process. The reaction initiation temperature was increased to 55°C, while the other parameters remained the same as in Example 1. The alkali solution was added dropwise at once.

[0058] Test results: Yield 83.5%, purity 95.6%, APHA color 280, and significantly increased byproducts.

[0059] The experimental data for each group are as follows: Example 1 89.0 97.8 140 2 93.1 Example 2 91.2 98.3 120 2 93.1 Example 3 90.1 98.1 125 2 92.6 Example 4 88.5 99.2 85 2 93.1 Comparative Example 1 78.7 94.2 360 5 0 Comparative Example 2 83.5 95.6 280 4 92.8 The data in the table above clearly show that the process of this invention is significantly superior to existing traditional processes and simple modified processes in terms of product yield, purity, color, raw material recovery, and waste control. Through the integrated process design of composite solvent system, low-temperature segmented ring opening, phase transfer catalysis to enhance mass transfer, gradient alkali control ring closure, nitrogen anti-oxidation protection, negative pressure raw material recovery, and simplified low-salt washing, side reactions are suppressed at the reaction mechanism level, improving product quality and yield, while reducing raw material consumption and waste emissions. It takes into account the needs of laboratory pilot-scale, pilot-scale, and large-scale continuous industrial production. A dedicated vacuum distillation process is set up to recover epichlorohydrin with a high recovery rate, and the recovered raw material can be directly recycled. The total raw material consumption is effectively reduced compared to traditional processes, significantly reducing raw material costs.

[0060] The triglycidyl-p-aminophenol prepared by this invention can be categorized into different application scenarios based on product purity and color grade: Industrial grade products (purity 97%~98%): used in general high-temperature resistant adhesives, general industrial anti-corrosion coatings, general composite matrix resins, and conventional electrical insulation components; High-purity products (98%–99% purity): used in carbon fiber composites, aerospace non-structural parts, high-voltage electrical insulation materials, and precision mechanical adhesives; Ultra-high purity refined products (purity ≥ 99%): used in high-end electronic component packaging, optical resin matrix, aerospace core structural composite materials, and military supporting polymer materials.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing triglycidyl-p-aminophenol by condensation, characterized in that: Includes the following steps: S1. Low-temperature ring-opening addition reaction: Epichlorohydrin and a composite low-carbon alcohol solvent are added to the reaction apparatus and stirred at room temperature until homogeneous. The system temperature is controlled at 25-40℃. p-Aminophenol is added in batches over 2-3 hours. The molar ratio of p-aminophenol to epichlorohydrin is 1:9-12. After the addition is completed, the temperature is raised to 45-52℃ and stirred for 3-5 hours to obtain a mixture containing tris(3-chloro-2-hydroxypropyl)p-aminophenol intermediate. S2, Gradient ring-closing reaction: The mixture obtained in step S1 is cooled to 40-48℃, and a sodium hydroxide aqueous solution with a mass fraction of 40%-50% is added dropwise in 2-4 batches to carry out the ring-closing reaction; the total amount of sodium hydroxide is 3.8-4.5 times the amount of p-aminophenol; after each batch of alkali solution is added, the temperature is maintained for 0.5-1h. After all the alkali solution is added, the temperature is raised to 50-58℃ and the ring-closing reaction is continued for 2-3h to obtain a crude reaction solution of triglycidyl p-aminophenol; S3. Raw material recovery: After the closed-loop reaction is completed, the crude reaction liquid is subjected to vacuum distillation to recover the epichlorohydrin that did not participate in the reaction. The recovered epichlorohydrin is directly reused in step S1. S4. Extraction and purification washing: Add organic solvent to the distillation residue for extraction, allow to stand and separate the layers to obtain the organic phase; wash the organic phase 1-2 times with a low-salt solution, and then wash with deionized water until the pH of the system is 6.5-7.

5. S5. Desolventizing to obtain the finished product: The washed organic phase is subjected to reduced pressure to remove the extraction solvent. After cooling, a pale yellow to light amber transparent viscous liquid is obtained, which is the triglycidyl-p-aminophenol product.

2. The method for preparing triglycidyl-p-aminophenol by condensation according to claim 1, characterized in that: In step S1, the composite low-carbon alcohol solvent is any one or a mixture of two of methanol, ethanol, and isopropanol, and the mass ratio of epichlorohydrin to the composite low-carbon alcohol solvent is 1:0.2 to 0.

5.

3. The method for preparing triglycidyl-p-aminophenol by condensation according to claim 1, characterized in that: In step S1 or step S2, a phase transfer catalyst is added. The phase transfer catalyst is a quaternary ammonium salt compound, and the amount added is 0.1% to 0.5% of the mass of p-aminophenol.

4. The method for preparing triglycidyl-p-aminophenol by condensation according to claim 3, characterized in that: The quaternary ammonium salt phase transfer catalyst is any one of tetraethylammonium bromide, benzyltriethylammonium chloride, and tetrabutylammonium chloride.

5. The method for preparing triglycidyl-p-aminophenol by condensation according to claim 1, characterized in that: The vacuum distillation process parameters in step S3 are: system temperature 60-70℃, vacuum degree -0.08MPa to -0.095MPa, and epichlorohydrin recovery rate ≥92%.

6. The method for preparing triglycidyl-p-aminophenol by condensation according to claim 1, characterized in that: The extraction organic solvent in step S4 is any one of toluene, xylene, and methyl isobutyl ketone, and the volume ratio of the extraction solvent to the distillation residue is 0.8:1 to 1.2:

1.

7. The method for preparing triglycidyl-p-aminophenol by condensation according to claim 1, characterized in that: The low-salt solution in step S4 is a sodium chloride aqueous solution with a mass fraction of 5% to 10%.

8. The method for preparing triglycidyl-p-aminophenol by condensation according to claim 1, characterized in that: In step S5, the vacuum degree for desolventizing is -0.09MPa to -0.098MPa, and the temperature is 75 to 90℃, until no solvent distills out of the system.

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