Synthesis process and equipment of triglycidyl isocyanurate

Abstract

The invention relates to the technical field of chemical synthesis, in particular to a synthesis process and equipment of triglycidyl isocyanurate, which comprises the following specific steps: A, dissolving cyanuric acid, epoxy chloropropane and a catalyst in a reaction kettle at 50-70 DEG C, then dropwise adding NaOH, and carrying out heat preservation reaction for 2-3 hours to obtain an intermediate reaction solution; b, cooling and filtering the reaction liquid containing the intermediate, and retaining mother liquor; c, heating the mother liquor and toluene to 100-120 DEG C, dropwise adding NaOH, and carrying out reflux reaction for 3-4 hours to obtain a TGIC toluene solution; d, cooling the toluene solution of TGIC to 50 DEG C, adjusting the pH value to 6-7, layering, taking a toluene layer, carrying out reduced pressure distillation to obtain a crude product, and crystallizing to separate out TGIC crystals; and E, washing the TGIC crystals by using three washing kettles a, b and c in series, and putting the TGIC crystals into the kettle a according to 60-80% of the capacity of the washing kettles. The invention aims to solve the problem that the intermittent operation mode of the existing single-kettle washing process is difficult to meet the industrial continuous production requirement.

Description

Technical Field

[0001] The invention relates to the technical field of chemical synthesis, and in particular to a synthesis process and equipment for triglycidyl isocyanurate. Background Art

[0002] As an important organic compound, triglycidyl isocyanurate (TGIC) plays an irreplaceable role in many fields. In the powder coating industry, it is a key curing agent that can significantly improve the corrosion resistance, wear resistance and weather resistance of the coating, and make the coating have excellent physical and chemical properties, so it is widely used in surface protection and decoration of buildings, home appliances, automotive parts, etc. In the field of electronic packaging materials, TGIC has become an ideal material for ensuring the stable operation of electronic components and resisting external environmental interference due to its excellent insulation properties, high glass transition temperature and good thermal stability, and has strongly promoted the development of the electronics industry towards miniaturization and high performance. In addition, in the preparation of advanced composite materials, TGIC can be used as a cross-linking agent to effectively enhance the mechanical strength and structural stability of the material, and provide high-performance basic materials for industries such as aerospace and high-end equipment manufacturing.

[0003] In the synthesis process of triglycidyl isocyanurate, TGIC crystals are washed in a single kettle, and the single kettle washing is intermittent. Each batch of crystals needs to go through the process of "feeding to washing to filtration to discharging", which requires periodic pauses, resulting in low equipment utilization, limited production capacity, and long time consumption. The inefficiency of the intermittent operation mode of the water washing process is difficult to meet the needs of industrial continuous production. Summary of the invention

[0004] The object of the present invention is to provide a synthesis process and equipment for triglycidyl isocyanurate, so as to solve the problem that the intermittent operation mode of the existing single-pot water washing process is difficult to meet the needs of industrial continuous production.

[0005] To achieve the above object, the present invention provides the following technical solutions: A synthesis process of triglycidyl isocyanurate, the specific steps are as follows: A, cyanuric acid, epichlorohydrin, and catalyst are dissolved in a reaction kettle at 50-70°C, and then NaOH is added dropwise. The mixture is kept warm for 2-3 hours to obtain an intermediate reaction liquid; B. Cool and filter the reaction solution containing the intermediate, and retain the mother liquor; C. Heat the mother liquor and toluene to 100-120°C, add NaOH dropwise and reflux for 3-4 hours to obtain TGIC toluene solution; D. Cool the toluene solution of TGIC to 50°C, adjust the pH to 6-7, separate the toluene layer and distill under reduced pressure to obtain a crude product, and crystallize TGIC crystals; E. Use three washing kettles a, b and c in series to wash TGIC crystals. Put TGIC crystals into kettle a according to 60%-80% of the capacity of the washing kettle. The TGIC crystals flow from kettle a to kettle b to kettle c. Finally, the discharged material is dried to obtain TGIC finished product. Fresh deionized water washing liquid is added to kettle c. The washing liquid flows from kettle c to kettle b to kettle a. Finally, the waste liquid is discharged. The liquid-to-solid ratio of the three washing kettles a, b and c is 1.5:1.

[0006] Preferably, in step E, kettle a is washed with kettle b, stirred at 50-60° C. for 15 minutes, the washing liquid is discharged to waste liquid treatment, and the TGIC crystals are transferred to kettle b; Use the washing liquid from kettle C to wash kettle B, stir at 50℃ for 10 minutes, and then flow the washing liquid into kettle A. Transfer the TGIC crystal to kettle C. Use fresh deionized water in kettle c and stir at 40°C for 5 minutes. The washing liquid flows into kettle b and TGIC crystals are discharged.

[0007] Preferably, in step E, when the COD of the washing liquid from kettle a is greater than 10000 mg / L, it is discharged to waste liquid treatment in advance.

[0008] Preferably, the TGIC crystals in kettle a are discharged from the bottom into a centrifuge, and after centrifugation, the solid phase is transferred to kettle b; The TGIC crystals in kettle b are discharged from the bottom into the centrifuge, and after centrifugation, the solid phase is transferred to kettle c; The TGIC crystals in kettle c are discharged from the bottom into the centrifuge, and after centrifugation, the solid phase is discharged.

[0009] Preferably, when the washing liquid from kettle b flows into kettle a, it is filtered to remove solid particles; When the washing liquid from kettle c flows into kettle b, it is filtered to remove solid particles.

[0010] Preferably, in step E, the first batch of TGIC crystals are put into kettle a, kettle a is washed with fresh deionized water, and the washing liquid is discharged to waste liquid treatment, the first batch of TGIC crystals are transferred to kettle b, kettle b is washed with fresh deionized water, and the washing liquid is retained in kettle a, the first batch of TGIC crystals are transferred to kettle c, kettle c is washed with fresh deionized water, and the washing liquid is retained in kettle b.

[0011] A synthesis device for triglycidyl isocyanurate comprises three water washing kettles, namely kettle a, kettle b and kettle c. The three water washing kettles are all provided with a feed valve, a discharge valve, a washing liquid inlet valve and a washing liquid outlet valve. The washing liquid outlet valve of kettle c is connected with the washing liquid inlet valve of kettle b through a first pipeline, and the washing liquid outlet valve of kettle b is connected with the washing liquid inlet valve of kettle a through a second pipeline. The three water washing kettles are used to implement step E of the synthesis process.

[0012] Preferably, a first filter is installed on the first pipe, and a second filter is installed on the second pipe.

[0013] Preferably, compressed air valves are installed at the outlet pipes of the first filter and the second filter, and switchable slag discharge ports are provided at the bottoms of the first filter and the second filter.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. By constructing a flow system where the crystal flows from kettle a to kettle b to kettle c, and the washing liquid flows from kettle c to kettle b to kettle a, the intermittent cycle of feeding, washing, filtering and discharging of a single kettle is broken through, and three equipments are simultaneously in different processing stages, kettle a is used for feeding washing, kettle b is used for intermediate washing, and kettle c is used for final washing, which improves the equipment turnover rate and helps meet the needs of industrial continuous production; 2. By setting filters on the first and second pipes of the washing liquid circulation, solid impurities in the washing liquid can be effectively intercepted to prevent impurities from settling and clogging in the pipes, thus ensuring the smoothness and stability of the washing liquid circulation system; 3. The filter bag is back-blown and cleaned by compressed air, and the clogged impurities can be removed without disassembling the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the structure of the filter of the present invention.

[0016] In the figure: 1. kettle a; 2. kettle b; 3. kettle c; 4. second pipeline; 5. washing liquid outlet valve; 6. washing liquid inlet valve; 7. vessel shell; 8. slag discharge port; 9. compressed air valve; 10. filter bag. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] See also Figure 1 to Figure 2 , the present invention provides a technical solution.

[0019] A synthesis process of triglycidyl isocyanurate, the specific steps are as follows: A. Put cyanuric acid (CA) and epichlorohydrin (ECH) into a reactor at a molar ratio of 1:4-6, add 0.5-1%wt quaternary ammonium salt catalyst, heat to 50-70°C and stir to dissolve, maintain the temperature until CA dissolves, slowly drop 20-30% NaOH solution (drip within 1-2 hours), keep warm and react for 2-3 hours to generate a reaction solution containing intermediates; In step A, the reaction temperature is controlled to be ≤70°C to avoid volatilization and decomposition of ECH, the stirring rate is 200-300 rpm, and the CA conversion rate detected by HPLC is ≥98% to complete the reaction. CA, ECH, and the catalyst are added in sequence in a reaction kettle equipped with a thermometer, a stirrer, and a constant pressure dropping funnel. The NaOH solution is placed in the dropping funnel and dripped at a uniform speed within 90 minutes (the flow rate is controlled by a peristaltic pump, 5.7 g / min), and the reaction temperature is maintained during the dripping process; If there is an excess of NaOH in step A, the mother liquor may contain a small amount of NaOH, which needs to be neutralized to neutrality with dilute hydrochloric acid before the ring-closing reaction.

[0020] B. Cool the reaction liquid of step A to room temperature, filter the reaction liquid to obtain a wet cake (containing NaCl and a small amount of mother liquor) and a mother liquor (containing intermediates and unreacted ECH), wash the cake with ECH 2-3 times (solid-liquid ratio is 1:3), merge the filtrate into the mother liquor for subsequent ring-closing reaction, use NaOH as alkali liquid in step A, and react to generate NaCl (by-product), which has extremely low solubility in organic solvents (such as epichlorohydrin, ECH), so it will precipitate in the form of crystals and can be separated by filtration. After filtration, a small amount of mother liquor (containing ECH, intermediates, etc.) is adsorbed on the surface of NaCl crystals to form a wet cake, and step B is intended to separate NaCl crystals (using a filter press); Wash the wet filter cake by transferring it to a washing tank, adding ECH (solid-liquid ratio 1:3), stirring and washing for 5 minutes, performing secondary filter pressing, and collecting the washing filtrate.

[0021] C. Put the mother liquor of step B and toluene (1-1.5 times the mass of the intermediate) into the reactor, start stirring (350rpm), slowly add NaOH (mother liquor intermediate: NaOH=1:3-4, NaOH excess 15-20% to neutralize HCl), raise the temperature to 100-120°C, slowly add 30% NaOH solution through a constant pressure dropping funnel (dropping rate ≤5mL / min), maintain reflux reaction for 3-4 hours, and obtain a toluene solution containing TGIC.

[0022] In step C, the by-product is NaCl precipitate, which can be removed by hot filtration after the reaction. The excess amount of NaOH is 15-20% (to ensure neutralization of HCl), and HCl is neutralized by the excess NaOH to generate NaCl precipitate. HPLC detection shows that the residual intermediate is less than 1%, and the reaction is complete.

[0023] In step C, the water separator separates the generated water to maintain the reaction system in an anhydrous environment (to avoid hydrolysis of TGIC). The water separator forms an azeotrope with toluene (boiling point 110.6°C) and water (azeotropic temperature 85°C), takes the water generated by the reaction out of the system, and refluxes the toluene to the reactor to achieve a dehydration-reflux cycle.

[0024] D. Cool the reaction solution in step C to 50°C, slowly add hydrochloric acid to adjust the pH to 6-7, let stand for 30 minutes to separate the layers, take the upper toluene solution containing TGIC, distill the toluene solution containing TGIC under reduced pressure (-0.09MPa, 50-60°C), recover toluene (purity ≥99%, recycled), and obtain a crude TGIC product (purity>90%). Dissolve the crude TGIC product in a methanol / water mixed solvent (methanol: water = 8:2) in an amount 3-5 times the quality of the crude product (e.g., 100kg of crude product plus 300-500L of solvent), heat to dissolve, cool to crystallize, precipitate TGIC crystals, and filter to separate the mother liquor. The crude TGIC product needs to be purified by crystallization (such as methanol / water system) to form a TGIC crystal precipitate. The TGIC crystal contains solvent and impurities, and the residual solvent (such as methanol), salt and water-soluble impurities need to be removed by water washing.

[0025] The specific crystallization steps are as follows: add methanol / water mixed solvent to the crystallization kettle, start stirring (150rpm), add crude TGIC, raise the jacket temperature to 60-70°C, dissolve for 30 minutes until clear, gradually cool down: 65°C to 40°C (30min) to 25°C (30min) to 5°C (60min), stir slowly throughout the process (50rpm), stand at 5°C for 2 hours to promote TGIC crystal growth, centrifuge (speed 3000rpm, 5min), discharge the mother liquor (containing impurities and solvent) into the solvent recovery system, and transfer the wet TGIC crystals to the water washing process.

[0026] E. Wash the wet TGIC crystals in three water washing kettles a, b and c in series, and then dry them to obtain the finished TGIC product.

[0027] The three water washing kettles in step E are connected in series, and the washing liquid flows from: c kettle 3 (fresh water) to b kettle 2 (c washing liquid) to a kettle 1 (b washing liquid) to waste liquid treatment, and the material flows from: material to a kettle 1 (initial washing with b kettle 2 washing liquid) to b kettle 2 (intermediate washing with c kettle 3 washing liquid) to c kettle 3 (fine washing with fresh water) to discharge.

[0028] Specific steps: material preparation: add TGIC crystals according to 60%-80% of the capacity of the water washing kettle (for example, if the water washing kettle is 1000L, add 600-800kg of material), and add fresh deionized water to kettle C 3 (liquid-solid ratio 1.5:1, such as 600kg of material plus 900L of water).

[0029] The washing stage is divided into three levels: Stage 1: Initial washing of kettle a 1 (using the washing liquid from the previous batch of kettle b 2), operation steps: open the feed valve of kettle a 1, add TGIC crystals, open the washing liquid valves from kettle b 2 to kettle a 1 (washing liquid inlet valve 6, washing liquid outlet valve 5), inject the washing liquid from kettle b 2 (low concentration, COD≈5000mg / L) into kettle a 1 (liquid-solid ratio 1.5:1), stir and heat to 50-60℃ (hot water circulation in the jacket to promote the dissolution of organic matter), stir for 15 minutes (speed 200rpm), stand and stratify for 5 minutes, the washing liquid from the upper part of kettle a 1 (high concentration, COD≈8000mg / L) is discharged into the high-concentration waste liquid tank through the overflow port, and the bottom is discharged into the centrifuge (or filter press). After centrifugation, the solid phase (the material after washing in kettle a 1) is transferred to kettle b 2; The second stage: washing in kettle b 2 (using the washing liquid from the previous batch of kettle c 3), operation steps: the solid phase of kettle a 1 is transferred to kettle b 2, the washing liquid valve from kettle c 3 to kettle b 2 is opened, and the washing liquid from the previous batch of kettle c 3 (fresh water, COD≈2000mg / L) is pumped into kettle b 2 (liquid-solid ratio 1.5:1), stirring and heating to 50°C (avoid high temperature to promote hydrolysis), stirring for 10 minutes (speed 150rpm), standing and stratifying for 5 minutes, the washing liquid (COD≈5000mg / L) from the upper part of kettle b 2 is retained through the overflow port to the next batch of kettle a 1 initial washing (connected through the washing liquid outlet valve 5, the washing liquid inlet valve 6, and the second pipeline 4), the bottom is discharged to the centrifuge, and the solid phase (the material after washing in kettle b 2) is transferred to kettle c 3; The third stage: c kettle 3 fine washing (fresh water), operation steps: the solid phase of b kettle 2 is transferred to c kettle 3, and fresh deionized water (liquid-solid ratio 1.5:1) is added, and the temperature is raised to 40℃ with stirring (low temperature reduces energy consumption), and stirred for 5 minutes (speed 100rpm), and allowed to stand for stratification for 10 minutes. The washing liquid (COD≈2000mg / L) in the upper part of c kettle 3 is retained through the overflow port to be washed in the next batch of b kettle 2, and the bottom material is discharged to the centrifuge, and the solid phase (the material after washing in c kettle 3, the moisture content ≤15%) enters the drying process.

[0030] After washing, the material in kettle c 3 was dried under vacuum at 60°C (-0.095MPa) until the water content was less than 0.3%.

[0031] Each kettle is provided with a feed valve, a discharge valve, a washing liquid inlet valve 6 and a washing liquid outlet valve 5. For example: the washing liquid outlet valve 5 of kettle c 3 is connected with the washing liquid inlet valve 6 of kettle b 2 through a first pipe, the washing liquid outlet valve 5 of kettle b 2 is connected with the washing liquid inlet valve 6 of kettle a 1 through a second pipe 4, and the washing liquid outlet valve 5 of kettle a 1 is used for wastewater discharge.

[0032] Each kettle washing liquid is sampled for COD testing (online sensor or offline titration), COD testing points: a kettle 1 washing liquid (after initial washing): COD≈8000mg / L (high concentration, circulation or treatment), b kettle 2 washing liquid (after intermediate washing): COD≈5000mg / L (circulated to a kettle 1), c kettle 3 washing liquid (after fine washing): COD≈2000mg / L (circulated to b kettle 2), when the COD of a kettle 1 washing liquid is greater than 10000mg / L, it is discharged to waste liquid treatment in advance, and the integrated SCADA system (data acquisition and monitoring control system, a computer-based industrial automation system) displays the liquid level, temperature and washing liquid flow of each kettle in real time, and generates a COD trend curve (historical data tracing).

[0033] In step E, the first batch of three stages are all washed with fresh water to establish a washing liquid gradient, and subsequent batches are circulated according to step E. When the first batch of TGIC crystals are put into kettle a 1, kettle a 1 is washed with fresh deionized water, and then the washing liquid is discharged to waste liquid treatment, and then the first batch of TGIC crystals flow from kettle a 1 to kettle b 2, kettle b 2 is also washed with fresh deionized water, and then the washing liquid is discharged to kettle a 1 to wash the second batch of TGIC crystals, and then the first batch of TGIC crystals flow from kettle b 2 to kettle c 3, kettle c 3 is washed with fresh deionized water, and then the washing liquid is discharged to kettle b 2 to wash the second batch of TGIC crystals.

[0034] A first filter is installed on the first pipe, and the filtered washing liquid flows into the washing liquid inlet of kettle b 2. A second filter is installed on the second pipe 4, and the filtered washing liquid flows into the washing liquid inlet of kettle a 1. The first and second filters are bag filters with a pore size of 50 μm to remove solid particles. The filter includes a housing 7 and a filter bag 10. When the filter has been running for 24 hours, stop the washing liquid from flowing into the filter, open the compressed air valve 9, and introduce compressed air (pressure is 0.5-0.7MPa) into the filter. The compressed air blows in the opposite direction to push out the solid particles intercepted on the surface of the filter bag 10, open the slag discharge port 8, and the pushed out solid particles are discharged into the waste slag collection bucket through the slag discharge port 8. The time is set to 3-5 minutes. After completion, close the compressed air valve 9 and restore the normal flow of washing liquid into the filter; In the filtration system, a compressed air valve 9 (0.5-0.7MPa) is installed at the outlet pipes of the first and second filters (on the opposite side of the washing liquid flow), and a slag discharge port 8 is set at the bottom of the filter to connect to the waste slag collection bucket, so as to achieve reverse blowing and removal of solid particles on the surface of the filter bag 10: after the filter has been running for 24 hours, the washing liquid is closed and the compressed air valve 9 is opened, and a high-pressure airflow is passed to blow toward the filter, so that the intercepted solid particles are separated from the filter bag 10 and discharged into the collection bucket through the bottom slag discharge port 8, and then the valve is closed to resume filtration.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A synthesis process of triglycidyl isocyanurate, characterized in that: The specific steps are as follows: A, cyanuric acid, epichlorohydrin, and catalyst are dissolved in a reaction kettle at 50-70°C, and then NaOH is added dropwise. The mixture is kept warm for 2-3 hours to obtain an intermediate reaction liquid; B. Cool and filter the reaction solution containing the intermediate, and retain the mother liquor; C. Heat the mother liquor and toluene to 100-120°C, add NaOH dropwise and reflux for 3-4 hours to obtain TGIC toluene solution; D. Cool the toluene solution of TGIC to 50°C, adjust the pH to 6-7, separate the toluene layer and distill under reduced pressure to obtain a crude product, and crystallize TGIC crystals; E. Use three washing kettles a, b and c in series to wash TGIC crystals. Put TGIC crystals into kettle a according to 60%-80% of the capacity of the washing kettle. The TGIC crystals flow from kettle a to kettle b to kettle c. Finally, the discharged material is dried to obtain TGIC finished product. Fresh deionized water washing liquid is added to kettle c. The washing liquid flows from kettle c to kettle b to kettle a. Finally, the waste liquid is discharged. The liquid-to-solid ratio of the three washing kettles a, b and c is 1.5:

1.

2. A process for synthesizing triglycidyl isocyanurate according to claim 1, characterized in that: In step E, kettle a is washed with the solution from kettle b, stirred at 50-60°C for 15 minutes, the washing solution is discharged to waste liquid treatment, and the TGIC crystals are transferred to kettle b; Use the washing liquid from kettle C to wash kettle B, stir at 50℃ for 10 minutes, and then flow the washing liquid into kettle A. Transfer the TGIC crystal to kettle C. Use fresh deionized water in kettle c and stir at 40°C for 5 minutes. The washing liquid flows into kettle b and TGIC crystals are discharged.

3. A synthesis process of triglycidyl isocyanurate according to claim 1, characterized in that: In step E, when the COD of the washing liquid from kettle a is greater than 10,000 mg / L, it is discharged to waste liquid treatment in advance.

4. A synthesis process of triglycidyl isocyanurate according to claim 2, characterized in that: The TGIC crystals in kettle a are discharged from the bottom into the centrifuge. After centrifugation, the solid phase is transferred to kettle b; The TGIC crystals in kettle b are discharged from the bottom into the centrifuge, and after centrifugation, the solid phase is transferred to kettle c; The TGIC crystals in kettle c are discharged from the bottom into the centrifuge, and after centrifugation, the solid phase is discharged.

5. A synthesis process of triglycidyl isocyanurate according to claim 2, characterized in that: When the washing liquid from kettle b flows into kettle a, it is filtered to remove solid particles; When the washing liquid from kettle c flows into kettle b, it is filtered to remove solid particles.

6. The synthesis process of triglycidyl isocyanurate according to claim 1, characterized in that: In step E, the first batch of TGIC crystals are put into kettle a, kettle a is washed with fresh deionized water, and the washing liquid is discharged to waste liquid treatment. The first batch of TGIC crystals are transferred to kettle b, kettle b is washed with fresh deionized water, and the washing liquid is retained in kettle a. The first batch of TGIC crystals are transferred to kettle c, kettle c is washed with fresh deionized water, and the washing liquid is retained in kettle b.

7. A synthesis equipment for triglycidyl isocyanurate, comprising three water washing kettles, namely kettle a, kettle b and kettle c, characterized in that: The three water washing kettles are all equipped with a feed valve, a discharge valve, a washing liquid inlet valve, and a washing liquid outlet valve. The washing liquid outlet valve of kettle c is connected to the washing liquid inlet valve of kettle b through a first pipeline, and the washing liquid outlet valve of kettle b is connected to the washing liquid inlet valve of kettle a through a second pipeline. The three water washing kettles are used to implement step E of the synthesis process described in claim 1.

8. The synthesis equipment of triglycidyl isocyanurate according to claim 7, characterized in that: A first filter is installed on the first pipe, and a second filter is installed on the second pipe.

9. The synthesis equipment of triglycidyl isocyanurate according to claim 8, characterized in that: Compressed air valves are installed at the outlet pipes of the first filter and the second filter, and switchable slag discharge ports are provided at the bottoms of the first filter and the second filter.

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