Triglycidyl isocyanurate and preparation method thereof

Abstract

The invention discloses a preparation method of triglycidyl isocyanurate and the triglycidyl isocyanurate. The preparation method comprises the following steps: S1, mixing cyanuric acid and epoxy chloropropane in a reaction solvent, reacting under the action of a catalyst, and extracting to obtain an intermediate reaction solution; s2, adding an anhydrous solid alkali reagent into the intermediate reaction solution, and carrying out a reaction to obtain a target reaction solution; and S3, performing purification operation on the basis of the target reaction liquid to obtain the triglycidyl isocyanurate, wherein the catalyst comprises two or more than two phase transfer catalysts. Through combined use of the phase transfer catalyst, the reaction conversion rate is improved, the input amount of epichlorohydrin is effectively reduced, the consumption and waste of raw materials are reduced, and the production efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of fine chemical synthesis, and in particular to a triglycidyl isocyanurate that can be applied to the pharmaceutical, materials and other industries, and its preparation method. Background Technology

[0002] Triglycidyl isocyanurate (TGIC) is a heterocyclic polyfunctional epoxy compound containing a triazine ring structure. Its molecular structure has both a stable triazine ring skeleton and an active epoxy group, which endows it with excellent chemical stability, heat resistance and reactivity, and it has important application value in industrial materials, pharmaceutical and chemical fields.

[0003] In the field of powder coatings, TGIC is a key crosslinking curing agent for carboxyl-containing polyester resins (PES) and polyacrylates (PA). Due to the triazine ring structure in its molecule, the cured system exhibits excellent heat resistance, weather resistance, and chemical corrosion resistance. Powder coatings prepared with TGIC are widely used in applications requiring stringent aging resistance, such as building exteriors, vehicle components, and outdoor facilities. The crosslinked network structure formed after curing gives the coating excellent mechanical strength, impact resistance, and arc resistance, while also possessing self-extinguishing flame-retardant properties, making it suitable for specialized fields such as electrical equipment and flame-retardant products.

[0004] In the electronics and new materials industries, TGIC is used as a modifier in electronic component packaging materials, printed circuit board substrates, and glass fiber reinforced composite materials due to its excellent insulation properties and thermal stability. With the increasing integration of electronic components, higher requirements are placed on the purity and performance stability of TGIC. Its application in high-precision electronic components relies on its low volatile content and high crosslinking efficiency.

[0005] In the pharmaceutical field, TGIC, as a component of topical ointments and medical adhesives, plays a role in transdermal drug delivery systems and medical dressings by utilizing its biocompatibility and moderate adhesive strength. Its chemical stability can ensure the performance stability of drug carriers during storage and use.

[0006] However, existing TGIC preparation and application technologies still have significant drawbacks. In traditional processes, to improve yield, a large excess of epichlorohydrin (ECH) is often added to react with the raw material cyanuric acid. These synthesis methods not only result in a significant waste of raw materials but also directly lead to high energy consumption in the post-processing distillation recovery of epichlorohydrin (ECH). Furthermore, they can cause ECH residue in the final TGIC product, affecting its curing performance and service life.

[0007] In addition, the existing process for synthesizing triglycidyl isocyanate (TGIC) also has side reactions such as ring-opening hydrolysis of the product under alkaline aqueous solvent, which reduces the product yield and stability. The ring-opening byproducts also increase the viscosity of the crude product, making it difficult to separate and obtain the target product with high purity. Summary of the Invention

[0008] To address at least one of the aforementioned problems, this application discloses a method for preparing triglycidyl isocyanurate. The method, through the combined use of phase transfer catalysts, improves the reaction conversion rate and effectively reduces the amount of ECH (electrochemically converted from hydrogen peroxide) required.

[0009] This application discloses a method for preparing triglycidyl isocyanurate, which may include: step S1: mixing cyanuric acid and epichlorohydrin in a reaction solvent, reacting under the action of a catalyst, and then extracting to obtain an intermediate reaction solution; step S2: adding an anhydrous solid base reagent to the intermediate reaction solution to react and obtain a target reaction solution; step S3: performing a purification operation based on the target reaction solution to obtain the triglycidyl isocyanurate; wherein the catalyst includes two or more phase transfer catalysts.

[0010] According to some embodiments of this application, in step S1, the molar ratio of cyanuric acid to epichlorohydrin is 1:3-10; or, the molar ratio of cyanuric acid to epichlorohydrin is 1:4-9.

[0011] According to some embodiments of this application, the catalyst, based on the mass of cyanuric acid, comprises a mixture of 0.3wt%-0.5wt% tetrabutylammonium bromide and 0.1wt%-0.5wt% benzyltrimethylammonium chloride, a mixture of 0.1wt%-0.5wt% tetrabutylammonium chloride and 0.1wt%-0.5wt% benzyltrimethylammonium chloride, or a mixture of 0.1wt%-0.3wt% hexadecyltrimethylammonium chloride and 0.1wt%-0.5wt% benzyltrimethylammonium chloride.

[0012] According to some embodiments of this application, the molar ratio of the anhydrous solid alkali reagent to cyanuric acid is 3-5:1.

[0013] According to some embodiments of this application, the anhydrous solid alkali reagent includes at least one of sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate, or sodium methoxide.

[0014] According to some embodiments of this application, in step S1, the reaction solvent includes a first polar solvent, including water, methanol or ethanol; or, the first polar solvent is water; the second polar solvent used for extraction includes at least one of ethyl acetate, dichloromethane, tetrahydrofuran, toluene or xylene.

[0015] According to some embodiments of this application, in step S2, the anhydrous solid alkali reagent is added to the intermediate reaction solution under low temperature conditions; the low temperature conditions are 0-20°C; or, the low temperature conditions are 0-10°C.

[0016] According to some embodiments of this application, the purification operation in step S3 includes: filtering the target reaction solution to remove insoluble substances, and concentrating the filtrate under reduced pressure to obtain an oily crude product containing the target product; adding the oily crude product to a third polar solvent, heating to dissolve, cooling to crystallize, filtering the crystals and drying to obtain the triglycidyl isocyanurate.

[0017] According to some embodiments of this application, the third polar solvent is methanol or ethanol; the volume of the third polar solvent is 1-5 times the weight of cyanuric acid; or, the volume of the third polar solvent is 1-2 times the weight of cyanuric acid.

[0018] In another aspect, this application provides a triglycidyl isocyanurate obtained using the preparation method described above.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0021] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this application and in its specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The terms "comprising" or "including," as used in this application, mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms "and / or" or "and / or" as used in this application include any and all combinations of one or more of the associated listed items. The terms "optionally" or "preferredly" as used in this application may refer to embodiments that provide certain beneficial effects in certain circumstances, but this does not limit the scope to embodiments that have inferior technical effects or are unavailable, nor is it intended to exclude or limit the embodiments related to this application.

[0022] The numerical range disclosed in this application should be considered continuous, encompassing any value between the maximum and minimum values ​​defining the range. The maximum and / or minimum values ​​may or may not be included within the numerical range. Unless otherwise stated, the numerical range AB may include any combination of real numbers from A to B, as well as any subrange consisting of any two real numbers. For example, the numerical range 0-5 may include, but is not limited to, 1-4, 2-3, 2.3-2.8, etc.

[0023] As described in the background section, existing TGIC synthesis technologies suffer from problems such as excessive waste of raw materials, numerous hydrolysis byproducts, high energy consumption for separation and purification, and residual ECH in the final product. To address these issues, this application provides a method for preparing triglycidyl isocyanate. By using a combination of phase transfer catalysts, the reaction conversion rate is improved, effectively reducing the amount of ECH input. Furthermore, this application uses anhydrous solid base reagents for ring-closed synthesis, effectively reducing the ring-opening hydrolysis of epoxides caused by the presence of aqueous solvents. This significantly improves reaction yield, reduces material input costs, lowers energy consumption for separation and purification, and minimizes ECH residue in the final product.

[0024] The following describes some preferred embodiments of this application. It should be noted that the following description is for illustrative purposes only and is not intended to limit the scope of protection of this application. The steps involved in this application may be performed precisely in sequence, or various steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0025] This application discloses a method for preparing triglycidyl isocyanurate, the preparation method comprising the following steps: Step S1: Cyanuric acid and epichlorohydrin are added to the reaction solvent and mixed. After reaction under the action of a catalyst, the intermediate reaction solution is obtained by extraction. Step S2: Add the anhydrous solid alkali reagent to the intermediate reaction solution to react and obtain the target reaction solution; Step S3: After performing purification operations based on the target reaction solution, the triglycidyl isocyanurate is obtained.

[0026] In step S1 above, cyanuric acid and epichlorohydrin can be weighed and added to the reaction solvent in a predetermined ratio and mixed. In some implementations, the molar ratio of cyanuric acid to epichlorohydrin is 1:3-10. For example, the molar ratio of cyanuric acid to epichlorohydrin can be an increase or decrease of 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, or higher. Optionally or preferably, the molar ratio of cyanuric acid to epichlorohydrin is 1:4-9.

[0027] The solvent used as the reaction solvent can be a polar solvent (referred to as the first polar solvent in this application), including but not limited to water, methanol, ethanol, propylene glycol, isopropanol, acetonitrile, tetrahydrofuran, formamide, trifluoroacetic acid, dimethyl sulfoxide, N,N-dimethylformamide, glycerol, acetic acid, or any combination thereof. Optionally or preferably, the first polar solvent can be water. The volume of the water solvent can be 1-10 times the weight of cyanuric acid, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 times, etc.; or, the volume of the water solvent can be 1-5 times the weight of cyanuric acid. Alternatively, any value within the above-mentioned ratio range is acceptable.

[0028] In some implementations, the catalyst may comprise a composition of two or more phase transfer catalysts. Some exemplary phase transfer catalysts may include, but are not limited to, quaternary ammonium salts (such as tetrabutylammonium bromide (TBAB), benzyltrimethylammonium chloride (DMBAC), benzyltriethylammonium chloride (TEBA), dodecyltrimethylammonium chloride (DTAC), hexadecyltrimethylammonium chloride (CTAC), etc.), quaternary phosphine salts (such as tetrabutylphosphine chloride (TBPC), trioctylmethylphosphine chloride, etc.), crown ethers (18-crown-6, 15-crown-5, dibenzo-18-crown-6, etc.), polyethers (polyethylene glycol (PEG-400), open-chain crown ethers (such as triethylene glycol dimethyl ether), etc.), tertiary amines (triethylamine, pyridine, N,N-dimethylaniline, etc.), heteropoly acids (phosphotungstic acid (H3PW), etc.). 12 O 40 ), silicotungstic acid (H4SiW) 12 O 40The catalyst may be a combination of two or more of tetrabutylammonium bromide, benzyltrimethylammonium chloride, and hexadecyltrimethylammonium chloride, etc., or ionic liquids (such as 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM])). Optionally or preferably, the catalyst may be a combination of two or more of tetrabutylammonium bromide, benzyltrimethylammonium chloride, and hexadecyltrimethylammonium chloride. Based on the mass of cyanuric acid, the catalyst comprises a mixture of 0.3wt%-0.5wt% tetrabutylammonium bromide and 0.1wt%-0.5wt% benzyltrimethylammonium chloride, a mixture of 0.1wt%-0.5wt% tetrabutylammonium chloride and 0.1wt%-0.5wt% benzyltrimethylammonium chloride, or a mixture of 0.1wt%-0.3wt% hexadecyltrimethylammonium chloride and 0.1wt%-0.5wt% benzyltrimethylammonium chloride. Using a combined phase-transfer catalyst can effectively enable sufficient contact between cyanuric acid and epichlorohydrin in a first polar solvent such as water, significantly increasing the reaction rate.

[0029] The reaction of cyanuric acid with epichlorohydrin under the action of a catalyst can be a heated reaction. The reaction temperature can be 60-100°C, and the reaction time can be 1-6 hours. Optionally or preferably, the reaction temperature can be 80-100°C, and the reaction time can be 2-6 hours. For example, the reaction temperature is 80°C, and the reaction time is 6 hours. According to the above heated reaction, the reactants generated by the reaction of cyanuric acid with epichlorohydrin can include compounds IA, IB, and IC with the following structures: The reaction between cyanuric acid and epichlorohydrin involves ring-opening. The epoxy ring of epichlorohydrin is opened, and it undergoes a nucleophilic substitution reaction with the hydroxyl group of cyanuric acid to produce the aforementioned compound. This reaction can also be called a ring-opening reaction.

[0030] The above-mentioned compound, after extraction in step S1, can be transferred to the extract to form the intermediate reaction solution. In some implementations, the second polar solvent used for extraction may include one or more of ethyl acetate, tetrahydrofuran, dichloromethane, chloroform, toluene, and xylene. For example, the second polar solvent may be dichloromethane or chloroform. During extraction, the volume of the second polar solvent may be 5-20 times the weight of cyanuric acid, for example, 5, 10, 15, 20 times, etc.; or any value within the above-mentioned range. Furthermore, extraction can be accelerated by stirring, such as mechanical stirring or magnetic stirring. The extraction time may be 10-60 minutes, any value within the above-mentioned time range is acceptable and is not limited to this application.

[0031] In step S2, compounds IA, IB, and IC undergo HCl removal under the action of the anhydrous solid base reagent, thereby forming the target product, triglycidyl isocyanurate. The anhydrous solid base reagent used may include at least one of sodium hydroxide, potassium hydroxide, barium hydroxide, calcium oxide, sodium oxide, sodium carbonate, potassium carbonate, trisodium phosphate, tripotassium phosphate, sodium methoxide, and sodium aminosulfonate. For example, the anhydrous solid base reagent may be sodium hydroxide. Using anhydrous solid base reagent avoids the hydrolysis of epoxides caused by the presence of water, significantly improving the reaction yield.

[0032] In some implementations, the anhydrous solid alkali can be added to the intermediate reaction solution under low-temperature conditions. These low-temperature conditions can be 0-20°C, for example, 0°C, 5°C, 10°C, 15°C, 20°C, etc., or any value within the above temperature range. Optionally or preferably, the low-temperature conditions are 0-10°C, for example, 10°C. The molar ratio of the added anhydrous solid alkali to cyanuric acid can be 3-5:1.

[0033] The reaction performed in step S2 can also be called a closed-loop reaction, for example, as shown below: The target product will be dissolved in the second polar solvent (i.e., the above-mentioned extract) to form the target reaction solution.

[0034] The above-mentioned closed-loop reaction can be carried out at 10-50°C for 2-16 hours. Optionally or preferably, the above-mentioned closed-loop reaction is carried out at 10-30°C, for example, at 25°C for 4 hours.

[0035] The purification operation in step S3 may include: filtering the target reaction solution to remove insoluble substances, and concentrating the filtrate under reduced pressure to obtain an oily crude product containing the target product; and adding the oily crude product to a third polar solvent, heating to dissolve it, cooling to crystallize, filtering the crystals and drying to obtain the triglycidyl isocyanurate.

[0036] In the above operations, insoluble substances can be salts, solid impurities, etc., produced during the reaction. Any filtration method can be used, such as atmospheric pressure filtration or vacuum filtration using a funnel and filter paper, or filtration using a microporous membrane or semi-permeable membrane. The filtrate can be concentrated under reduced pressure, such as by rotary evaporation, vacuum concentration, multi-effect evaporation, or vacuum drying. Optionally or preferably, the temperature for vacuum concentration can be 40-80°C, for example, 40°C, 50°C, 60°C, 70°C, 80°C, or any value within the above range.

[0037] The third polar solvent (e.g., methanol or ethanol) can be used to redissolve or redissolve the crude oily product obtained after vacuum concentration. The volumetric volume can be 1-5 times the weight of cyanuric acid. Optionally or preferably, the volumetric volume of the third polar solvent can be 1-2 times the weight of cyanuric acid. Heating can be performed at 40-80°C to ensure complete dissolution of the crude oily product. During this process, stirring (e.g., mechanical stirring / magnetic stirring) can be used to accelerate the dissolution of the crude product in the third polar solvent. Subsequently, based on the characteristic of solubility changing with temperature, cooling crystallization is performed to precipitate the target product (i.e., triglycidyl isocyanurate) from the third polar solvent. In some implementations, the crystallization temperature for cooling crystallization can be 0-20°C, for example, 0°C, 10°C, 20°C, etc. Optionally or preferably, the crystallization temperature for cooling crystallization is 10°C.

[0038] After crystal precipitation, the crystals can be filtered and dried to obtain the target product, namely triglycidyl isocyanurate. The filtration method can be as described above, and the crystals can be dried using natural air drying, heat drying, suction drying, vacuum drying, freeze drying, or other suitable methods. For example, the filtered crystals can be vacuum dried to obtain the final target product. The vacuum drying temperature can be between 50-80°C, for example, 50°C, 60°C, 70°C, 80°C, etc. Optionally or preferably, the vacuum drying temperature is 60°C.

[0039] The method for preparing triglycidyl isocyanurate disclosed in this application improves the reaction conversion rate and effectively reduces the amount of raw material ECH by using a combination of phase transfer catalysts. Furthermore, the synthesis strategy in this application, which involves extracting and separating the reaction intermediate with a non-water-soluble organic solvent and then adding an alkaline reagent to close the ring, can effectively reduce the ring-opening hydrolysis problem of epoxides caused by the presence of aqueous solvents. This significantly improves the reaction yield, reduces material input costs, reduces separation and purification energy consumption, and eliminates existing technical problems such as ECH residue in the final product.

[0040] This application also discloses a triglycidyl isocyanurate compound that can be obtained based on the preparation method described above.

[0041] Unless otherwise specified, the reagents, materials and instruments used in the following embodiments are commercially available products that can be purchased.

[0042] Example 1 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst tetrabutylammonium bromide (75 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (57 g, 619 mmol), and water (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to 10 °C. Solid sodium hydroxide (20 g, 511 mmol) was slowly added, and the mixture was stirred at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80 °C and stirred for 30 minutes, and then cooled to 10 °C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60 °C to obtain 43 g of the target triglycidyl isocyanurate (TGIC) product, a pure white solid product with a yield of 93.35%.

[0043] The proton NMR spectral data of the product are as follows: 1 H NMR (400 MHz, DMSO-d6) δ 4.14 – 4.01 (m, 3H), 4.01 – 3.87 (m, 3H), 3.28 – 3.19 (m, 3H), 2.86 – 2.78 (m, 3H), 2.68 (dq, J = 5.3, 2.5 Hz, 3H). Example 2 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst tetrabutylammonium chloride (65 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (57 g, 619 mmol), and water (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to 10 °C. At ℃, 20 g of solid sodium hydroxide (511 mmol) was slowly added, followed by stirring at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80 ℃ and stirred for 30 minutes, then cooled to 10 ℃ to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60 ℃ to obtain 42.8 g of the target triglycidyl isocyanate (TGIC) product, a pure white solid product with a yield of 93%.

[0044] Example 3 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (57 g, 619 mmol), and water (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to 1 °C. At 0°C, 20 g of solid sodium hydroxide (511 mmol) was slowly added, followed by stirring at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80°C and stirred for 30 minutes, then cooled to 10°C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60°C to obtain 43.6 g of the target triglycidyl isocyanate (TGIC) product, a pure white solid product with a yield of 94.6%.

[0045] Example 4 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (100 g, 1.08 mol), and water solvent (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added, and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to 1 °C. At 0°C, 20 g of solid sodium hydroxide (511 mmol) was slowly added, followed by stirring at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80°C and stirred for 30 minutes, then cooled to 10°C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60°C to obtain 44.5 g of the target triglycidyl isocyanate (TGIC) product, a pure white solid product with a yield of 96.6%.

[0046] Comparative Example 1 In Comparative Example 1, a single-phase transfer catalyst, tetrabutylammonium bromide, was used. The specific process is as follows: In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst tetrabutylammonium bromide (75 mg, 0.23 mmol), epichlorohydrin (57 g, 619 mmol), and water (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was cooled to 10 °C, and solid sodium hydroxide was slowly added. 20 g (511 mmol), then stirred at room temperature for 4 h; filtered to remove insoluble solid salts, the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product, the crude product was diluted with ethanol (30 mL), heated to 80 °C and stirred for 30 min, then cooled to 10 °C to crystallize, the white solid was collected by filtration, the filter cake was washed with cold ethanol (10 mL), the solid product was dried under vacuum at 60 °C to obtain 35.6 g of the target triglycidyl isocyanurate (TGIC) product, a pure white solid product, with a yield of 77.3%.

[0047] Comparative Example 2 In Comparative Example 2, a single-phase transfer catalyst, benzyltrimethylammonium chloride, was used. The specific process is as follows: In a reaction flask, cyanuric acid (20 g, 155 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (57 g, 619 mmol), and water (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was cooled to 10 °C, and solid hydroxide was slowly added. Sodium (20 g, 511 mmol) was added and stirred at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80 °C and stirred for 30 min, and then cooled to 10 °C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60 °C to obtain 39.6 g of the target triglycidyl isocyanate (TGIC) product, a pure white solid product with a yield of 86%.

[0048] Comparative Example 3 In Comparative Example 3, a single-phase transfer catalyst, hexadecyltrimethylammonium chloride, was used. The specific process is as follows: In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), epichlorohydrin (57 g, 619 mmol), and water (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to 10 °C, and solid hydroxide was slowly added. Sodium chloride (20 g, 511 mmol) was added and stirred at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80 °C and stirred for 30 min, and then cooled to 10 °C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60 °C to obtain 36.4 g of the target triglycidyl isocyanate (TGIC) product, a pure white solid product with a yield of 79%.

[0049] Comparative Example 4 In Comparative Example 4, a single-phase transfer catalyst, tetrabutylammonium chloride, was used. The specific process is as follows: In a reaction flask, cyanuric acid (20 g, 155 mmol), tetrabutylammonium chloride (65 mg, 0.23 mmol), epichlorohydrin (57 g, 619 mmol), and water (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was cooled to 10 °C, and solid sodium hydroxide was slowly added. 20 g (511 mmol), then stirred at room temperature for 4 h; filtered to remove insoluble solid salts, the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product, the crude product was diluted with ethanol (30 mL), heated to 80 °C and stirred for 30 min, then cooled to 10 °C to crystallize, the white solid was collected by filtration, the filter cake was washed with cold ethanol (10 mL), the solid product was dried under vacuum at 60 °C to obtain 36.3 g of the target triglycidyl isocyanurate (TGIC) product, a pure white solid product, with a yield of 78.8%.

[0050] Example 5 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (43 g, 465 mmol), and water (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled. At 10°C, 20 g of solid sodium hydroxide (511 mmol) was slowly added, followed by stirring at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80°C and stirred for 30 minutes, then cooled to 10°C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60°C to obtain 41 g of the target triglycidyl isocyanate (TGIC) product, a pure white solid product with a yield of 89%.

[0051] Example 6 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (71.6 g, 775 mmol), and water solvent (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added, and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to [temperature missing]. Solid sodium hydroxide (20 g, 511 mmol) was slowly added at 10 °C, and then stirred at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80 °C and stirred for 30 minutes, and then cooled to 10 °C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60 °C to obtain 43.7 g of the target triglycidyl isocyanate (TGIC) product, a pure white solid product with a yield of 94.8%.

[0052] Example 7 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (86 g, 929 mmol), and water (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to [temperature missing]. At 10°C, 20 g of solid sodium hydroxide (511 mmol) was slowly added, followed by stirring at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80°C and stirred for 30 minutes, then cooled to 10°C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60°C to obtain 44 g of the target triglycidyl isocyanurate (TGIC) product, a pure white solid product with a yield of 95.5%.

[0053] Example 8 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (115 g, 1.24 mol), and water solvent (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added, and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to 1 °C. At 0°C, 20 g of solid sodium hydroxide (511 mmol) was slowly added, followed by stirring at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80°C and stirred for 30 minutes, and then cooled to 10°C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60°C to obtain 44.2 g of the target triglycidyl isocyanate (TGIC) product, a pure white solid product with a yield of 95.9%.

[0054] Example 9 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (129 g, 1.39 mol), and water solvent (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added, and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to 1 °C. At 0°C, 20 g of solid sodium hydroxide (511 mmol) was slowly added, followed by stirring at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80°C and stirred for 30 minutes, then cooled to 10°C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60°C to obtain 43.8 g of the target triglycidyl isocyanate (TGIC) product, a pure white solid product with a yield of 95.0%.

[0055] Example 10 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (143 g, 1.55 mol), and water solvent (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. After cooling to room temperature, dichloromethane (200 mL) was added, and the mixture was stirred and extracted for 30 min. The mixture was allowed to stand and separate into layers. The upper aqueous phase was removed, and the lower organic phase was collected and separated. The mixture was then cooled to [temperature missing]. At 10°C, 20 g of solid sodium hydroxide (511 mmol) was slowly added, followed by stirring at room temperature for 4 h. The insoluble solid salt was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain a colorless oily crude product. The crude product was diluted with ethanol (30 mL), heated to 80°C and stirred for 30 minutes, and then cooled to 10°C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60°C to obtain 43 g of the target triglycidyl isocyanurate (TGIC) product, a pure white solid product with a yield of 93.3%.

[0056] Comparative Example 5 In a reaction flask, cyanuric acid (20 g, 155 mmol), phase transfer catalyst hexadecyltrimethylammonium chloride (74 mg, 0.23 mmol), benzyltrimethylammonium chloride (58 mg, 0.31 mmol), epichlorohydrin (57.3 g, 620 mmol), and water solvent (40 mL) were added sequentially. The mixture was heated to 80 °C and reacted for 6 h. Then, the temperature was lowered to 10 °C, and 50% of the cyanuric acid was slowly added. A sodium hydroxide solution (40 g, 511 mmol) was prepared, stirred at room temperature for 4 h, and concentrated under reduced pressure to remove most of the solvent water, yielding a colorless to pale yellow solid-liquid oil. The solution was diluted with ethanol (50 mL), filtered to remove insoluble salts, and the filtrate was concentrated again under reduced pressure to obtain a colorless to pale yellow oil. This was diluted again with ethanol (30 mL), heated to 80 °C and stirred for 30 min, then cooled to 10 °C to crystallize. The white solid was collected by filtration, and the filter cake was washed with cold ethanol (10 mL). The solid product was dried under vacuum at 60 °C to obtain 32.3 g of the target triglycidyl isocyanurate (TGIC) product, a pure white solid product with a yield of 70%.

[0057] The components and amounts used in the above examples and comparative examples, as well as the corresponding reaction yields, are shown in Table 1 below.

[0058] Table 1. Relevant data for the examples and comparative examples. From the above examples and comparative examples, it can be seen that, as shown in Examples 1-4, the combined use of catalysts can achieve a high yield of the target product triglycidyl isocyanurate (TGIC) with a lower amount of epichlorohydrin. Examples 1-3 and Comparative Examples 1-4 demonstrate that the combined use of catalysts can achieve a higher product yield, and it can be seen that the combination of hexadecyltrimethylammonium chloride and benzyltrimethylammonium chloride results in a higher reaction yield. Examples 3-4 and Examples 5-10 show that the amount of epichlorohydrin added is directly related to the yield. When the epichlorohydrin equivalence ratio is between 3 and 7 equivalences, the yield increases positively with the amount added, which is consistent with the existing technology that increases the yield by increasing the amount of epichlorohydrin equivalence. However, when the equivalence ratio exceeds 7 equivalences, the yield decreases, which may be related to post-processing purification and crystallization; excessive epichlorohydrin can affect the crystallization yield. As can be seen from Example 3 and Comparative Example 5, when the ring-closing reaction is carried out using an aqueous solvent as the reaction solvent, the yield will decrease significantly. This is because when a large amount of aqueous solvent is present, the product or intermediate will undergo a ring-opening side reaction, thereby reducing the yield of the product. This further proves the innovative advantage of using a non-aqueous solvent for the ring-closing reaction in this application.

[0059] This application has described the basic concepts. Obviously, for those skilled in the art, the above detailed disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this application.

[0060] Furthermore, this application uses specific terms to describe its embodiments. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this application do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0061] Similarly, it should be noted that, in order to simplify the description of this application and thus aid in the understanding of one or more embodiments, the foregoing description of the embodiments of this application sometimes combines multiple features into a single embodiment or its description. However, this disclosure method does not imply that the subject matter of this application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0062] Finally, it should be understood that the embodiments described in this application are merely illustrative of the principles of the embodiments of this application. Other modifications may also fall within the scope of this application. Therefore, alternative configurations of the embodiments of this application are considered as examples and not limitations, and are regarded as consistent with the teachings of this application. Accordingly, the embodiments of this application are not limited to the embodiments explicitly described and illustrated in this application.

Claims

1. A process for the preparation of isocyanuric acid triglycidyl ester, characterized by, The preparation method comprises: Step S1: mixing cyanuric acid and epichlorohydrin in a reaction solvent, reacting under the action of a catalyst, and obtaining an intermediate reaction liquid through extraction; Step S2: putting anhydrous solid base reagent into the intermediate reaction liquid to obtain a target reaction liquid; Step S3: performing a purification operation based on the target reaction liquid to obtain the isocyanuric acid triglycidyl ester; wherein The catalyst comprises two or more phase transfer catalysts.

2. The method of preparing isocyanuric acid triglycidyl ester according to claim 1, characterized in that, In the step S1, the molar ratio of cyanuric acid to epichlorohydrin is 1:3-10; or the molar ratio of cyanuric acid to epichlorohydrin is 1:4-9.

3. The method of preparing isocyanuric acid triglycidyl ester according to claim 1, characterized in that, The catalyst comprises, based on the mass of cyanuric acid, 0.3wt%-0.5wt% of a mixture of tetrabutylammonium bromide and benzyltrimethylammonium chloride, 0.1wt%-0.5wt% of a mixture of tetrabutylammonium chloride and benzyltrimethylammonium chloride, or 0.1wt%-0.3wt% of a mixture of cetyltrimethylammonium chloride and benzyltrimethylammonium chloride.

4. The method of preparing isocyanuric acid triglycidyl ester according to claim 1, characterized by, The molar ratio of the anhydrous solid base reagent to cyanuric acid is 3-5:

1.

5. The method of preparing isocyanuric acid triglycidyl ester according to claim 1, characterized by, The anhydrous solid base reagent comprises at least one of sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate, or sodium methoxide.

6. The process for the preparation of isocyanuric acid triglycidyl ester according to any one of claims 1 to 5, characterized in that, In the step S1, the reaction solvent comprises a first polar solvent, including water, methanol, or ethanol; or the first polar solvent is water; and a second polar solvent used for extraction comprises at least one of ethyl acetate, dichloromethane, tetrahydrofuran, toluene, or xylene.

7. The process for the preparation of isocyanuric acid triglycidyl ester according to any one of claims 1 to 5, characterized in that, In the step S2, the anhydrous solid base reagent is put into the intermediate reaction liquid under low-temperature conditions; the low-temperature conditions are 0-20°C; or the low-temperature conditions are 0-10°C.

8. The process for the preparation of isocyanuric acid triglycidyl ester according to any one of claims 1 to 5, characterized in that, The purification operation in the step S3 comprises: Filtering the target reaction liquid to remove insoluble substances, and concentrating the filtrate under reduced pressure to obtain an oily crude product containing the target product; Adding the oily crude product into a third polar solvent, warming to dissolve, then cooling to crystallize, filtering the crystals, and drying to obtain the isocyanuric acid triglycidyl ester.

9. The method of preparing isocyanuric acid triglycidyl ester according to claim 8, characterized in that, The third polar solvent is methanol or ethanol; the volume of the third polar solvent is 1-5 times the weight of cyanuric acid; or the volume of the third polar solvent is 1-2 times the weight of cyanuric acid.

10. The isocyanuric acid triglycidyl ester obtained by the preparation method according to any one of claims 1-9.

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