Method for synthesizing tetrabromobisphenol A based on phase transfer catalysis
By using cetyl diphenyl ether disulfonic acid as a phase transfer catalyst in the synthesis process of tetrabromobisphenol A, combined with ultrasonic irradiation, the problem of slow bromination reaction rate in the existing technology is solved, and high efficiency, Low energy consumption synthesis of tetrabromobisphenol A with significantly improved yield and purity.
Patent Information
- Application Number
- CN202411599176.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-11
- Publication Date
- 2025-01-21
AI Technical Summary
In the prior art, the bromination reaction rate of tetrabromobenzene A is slow, and when the stirring rate is increased to increase the contact frequency of organic molecules, it is easy to lead to organic emulsification and lead to a decrease in yield.
Using a method based on phase transfer catalytic, by using organic acid hexisyxyl di -sulfonic acid with certain phase metastasis and catalytic functions in the reaction, replacing traditional inorganic acids, thereby speeding up the bromide reaction rate, and assisting the use of ultrasonic waves to use ultrasonic waves Elite to improve the oxidation of hydrogen peroxide.
The bromination reaction rate is significantly improved, the reaction time is shortened, the yield and purity of tetrabromobisphenol A are improved, the process is simple and reasonable, and the energy consumption is low.
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of flame retardants, and in particular to a method for synthesizing tetrabromobisphenol A based on phase transfer catalysis. Background Art
[0002] As a flame retardant, tetrabromobisphenol A is widely used in plastics, rubber, textiles, fibers, paper and other fields. It has high bromine content, good thermal stability, excellent UV resistance, and lower exudation than other brominated flame retardants. It is particularly suitable for flame retardant production of computers, fax machines, telephones, copiers, home appliances and other products.
[0003] At present, the industry mainly synthesizes tetrabromobisphenol A through the bromine / hydrogen peroxide in-situ bromination-oxidation method. This method uses the oxidizing property of hydrogen peroxide to oxidize the bromide hydrogen generated by bromination into bromine, thereby improving the utilization rate of bromine and reducing pollution to the environment. In theory, this method can utilize all the bromine, but in the actual reaction process, the bromination reaction rate is particularly slow. The main limiting factor is the low efficiency of bromination. If the frequency of contact and collision of organic molecules is increased by increasing the stirring rate, it is easy to cause organic emulsification and the yield of tetrabromobisphenol A decreases. Summary of the invention
[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the object of the present invention is to provide a method for synthesizing tetrabromobisphenol A based on phase transfer catalysis.
[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A method for synthesizing tetrabromobisphenol A based on phase transfer catalysis comprises the following steps: S100, sequentially adding bisphenol A and the hexadecyl diphenyl ether disulfonic acid to an organic solvent at a temperature of 20° C. to 28° C., stirring, and dropwise adding hydrogen peroxide and bromine, reacting for 1.5 h to 2.5 h to obtain a mixed solution; S200, stirring, heating the mixed solution to 80° C. to 90° C., stirring for 0.5 h to 1 h, irradiating the mixed solution with ultrasound with an irradiation power of 40 W to 60 W for 15 min to 30 min, and after irradiation, standing for 15 min to 30 min, separating and removing the first water layer to obtain a first organic solution layer; S300, adding sodium nitrite solution to the first organic solution layer at a temperature of 80°C to 90°C, stirring for 0.5h to 1h, separating and removing the second water layer to obtain a second organic solution layer; S400, adding water to the second organic solution layer, the temperature is 80°C to 90°C, stirring for 0.5h to 1h, separating and removing the third water layer, to obtain a third organic solution layer; S500, repeat step S400 2 to 4 times to obtain a fourth organic solution layer, cool it to 2°C to 6°C, filter it with suction, and dry it to obtain tetrabromobisphenol A.
[0006] The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis provided by the present invention replaces the inorganic acid commonly used in the bromination process of bisphenol A with the organic acid hexadecyl diphenyl ether disulfonic acid having a certain phase transfer catalytic function, so that the hypobromite ions generated in the bromination process of bisphenol A are deprotonated by the organic acid in the aqueous phase, and then form conjugated ion pairs with the organic acid radical ions, and are transferred to the organic phase under the influence of the straight-chain alkyl group. Since the activity of the bromide ions in the conjugated ion pair is higher than that of the bromide anions in the bromine element and the hydrogen bromide solution, the reaction activity is higher. Benefiting from the driving effect of the phase transfer, the bromide ions are accelerated to transfer to the organic phase, and the reaction rate is further improved.
[0007] Hexadecyl diphenyl ether disulfonic acid is amphiphilic, containing a pair of sulfonic acid groups connected to the diphenyl ether benzene ring skeleton and a long-chain hydrophobic alkyl group, which has excellent solubility and coupling. In addition, the ether bond connecting the two benzene rings allows the benzene to rotate around the oxygen, so that the distance between the sulfonic acid groups can be changed, greatly improving its binding rate with the dense ionic structure. Since the affinity between the ion pair and the organic phase determines the rate of the phase transfer catalytic reaction, the reaction rate of hexadecyl diphenyl ether disulfonic acid far exceeds that of inorganic acids and commonly used monosulfonic acids due to its unique molecular structure.
[0008] At the same time, with the assistance of ultrasonic irradiation, the oxidizing property of hydrogen peroxide is indirectly improved, which has the advantages of fast bromination speed, short reaction time and high product quality.
[0009] Furthermore, in step S100, the preparation process of hexadecyl diphenyl ether disulfonic acid comprises the following steps: S110, take C 16 The α-olefin and diphenyl ether undergo alkylation reaction under the catalysis of anhydrous aluminum chloride, the reaction temperature is 80℃~90℃, the reaction time is 4h~6h, and hexadecyl diphenyl ether is obtained; S120, using the hexadecyl diphenyl ether as a raw material, sulfur trioxide as a sulfonating agent, and urea as a cosolvent to prepare hexadecyl diphenyl ether disulfonic acid.
[0010] Furthermore, in step S110, C 16 The molar ratio of the α-olefin to the added amount of diphenyl ether is 1:(1-1.2); in step S120, the molar ratio of hexadecyl diphenyl ether to sulfur trioxide is 1:(2-2.5).
[0011] Furthermore, in step S100, the organic solvent is one or more of chlorobenzene, ethyl acetate, propyl acetate, acetone, butanone, methanol, ethanol, and isopropanol.
[0012] Furthermore, in step S100, the molar ratio of bisphenol A, bromine and hydrogen peroxide added is 1:(2-2.2):(2.1-2.3).
[0013] Furthermore, in step S100, the mass of the added hexadecyl diphenyl oxide disulfonic acid is 0.7% to 1.1% of the mass of the added bisphenol A.
[0014] With the increase of the addition amount of hexadecyl diphenyl ether disulfonic acid, the final yield of tetrabromobisphenol A gradually increased. However, if the addition amount is further increased, its phase transfer rate reaches saturation and the product yield no longer increases. Therefore, the upper limit of the addition ratio can be maintained at about 1.05%. Too high an addition ratio will affect the purity of the final product.
[0015] Furthermore, in step S100, the mass ratio of bisphenol A to the organic solvent added is 1:3 to 1:5.
[0016] Furthermore, in step S200, the irradiation power is 45W to 55W.
[0017] Furthermore, in step S300, the mass concentration of the sodium nitrite solution is 10% to 14%, and the mass of the added sodium nitrite solution is 8% to 12% of the mass of the first organic solution layer.
[0018] Furthermore, in step S400, the mass of water added is 8% to 12% of the mass of the second organic solution layer.
[0019] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The invention provides a method for synthesizing tetrabromobisphenol A based on phase transfer catalysis. The method can greatly improve the bromination reaction rate, accelerate the bromination reaction rate in a phase transfer catalytic manner, and indirectly improve the oxidizability of hydrogen peroxide with the assistance of ultrasonic irradiation. The method has the advantages of fast bromination speed, short reaction time and high product quality, and the process is simple and reasonable, the energy consumption is low, and the yield of tetrabromobisphenol A is high.
[0020] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION
[0021] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.
[0022] In the following examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.
[0023] Example 1 Take C 16 The α-olefin and diphenyl ether are alkylated under the catalysis of anhydrous aluminum chloride, the reaction molar ratio is 1:1.05, the reaction temperature is 85℃, and the reaction time is 5h. Hexadecyl diphenyl ether is used as raw material, sulfur trioxide is used as sulfonating agent, urea is used as cosolvent, the reaction molar ratio is 1:2.12, the reaction temperature is 95℃, the reaction time is 1.5h, and hexadecyl diphenyl ether disulfonic acid can be obtained by purification after the reaction.
[0024] Saturated chlorobenzene (913.2 g) was used as an organic solvent, and bisphenol A (228.3 g, 1 mol), bromine (335.6 g, 2.10 mol), and 30% hydrogen peroxide (249.3 g, 2.20 mol) were used as raw materials. First, bisphenol A was added to the chlorobenzene solution, and then hexadecyl diphenyl ether disulfonic acid (1.83 g) was added to the mixed solution, and the added mass was 0.80% of the added mass of bisphenol A. Stirring was started, and the bromination reaction temperature was controlled to be maintained between 25°C. Hydrogen peroxide and bromine were gradually added dropwise. The bromination reaction dropwise addition time was maintained at about 1.8 hours, and the bromination reaction was considered to be completed to obtain a mixed solution.
[0025] The mixed solution obtained in the above process was kept stirred, and the temperature was continued to rise to 85°C, and stirred for 0.5h. The mixed solution was then irradiated with ultrasound with an irradiation power of 50w for 15min. After the irradiation was completed, the mixture was allowed to stand for 20min, and the first water layer (242.5g) was separated to obtain the first organic solution layer (1483.5g).
[0026] Add 12% sodium hypochlorite solution (148.3 g) to the first organic solution layer, the mass of which is 10% of the mass of the first organic solution layer, maintain the temperature at 85°C, keep stirring for 30 minutes, separate and remove the second water layer (152.4 g), and obtain the second organic solution layer (1478.2 g); Then, 10% of the mass of distilled water (147.8 g) was added to the second organic solution layer, the temperature was maintained at 85°C, and the mixture was stirred for 30 minutes. The third water layer (147.2 g) was separated and removed to obtain a third organic solution layer (1477.6 g). This was repeated three times to obtain a fourth organic solution layer (1475.8 g). The fourth organic solution layer was cooled to 4°C, filtered, and the solution (816.2 g) was removed to obtain a tetrabromobisphenol A wet cake (659.2 g). The tetrabromobisphenol A (526.0 g) was obtained by vacuum drying.
[0027] The yield of tetrabromobisphenol A in this example is 96.72%, and its purity is 99.83% as detected by liquid chromatography.
[0028] Example 2 Take C 16 The α-olefin and diphenyl ether are alkylated under the catalysis of anhydrous aluminum chloride, the reaction molar ratio is 1:1.05, the reaction temperature is 85℃, and the reaction time is 5h. Hexadecyl diphenyl ether is used as raw material, sulfur trioxide is used as sulfonating agent, urea is used as cosolvent, the reaction molar ratio is 1:2.12, the reaction temperature is 95℃, the reaction time is 1.5h, and hexadecyl diphenyl ether disulfonic acid can be obtained by purification after the reaction.
[0029] Saturated chlorobenzene (730.6 g) was used as an organic solvent, and bisphenol A (182.6 g, 0.8 mol), bromine (268.5 g, 1.68 mol), and 30% hydrogen peroxide (199.5 g, 1.76 mol) were used as raw materials. First, bisphenol A was added to the chlorobenzene solution, and then hexadecyl diphenyl ether disulfonic acid (1.74 g) was added to the mixed solution, and the added mass was 0.95% of the added mass of bisphenol A. Stirring was started, and the bromination reaction temperature was controlled to be maintained between 26°C. Hydrogen peroxide and bromine were gradually added dropwise. The bromination reaction dropwise addition time was maintained at about 1.85 h, and the bromination reaction was considered to be completed to obtain a mixed solution.
[0030] The mixed solution obtained in the above process was kept stirred, and the temperature was continued to rise to 85°C, and stirred for 0.5h. The mixed solution was then irradiated with ultrasound with an irradiation power of 50w for 18min. After the irradiation was completed, the mixture was allowed to stand for 25min, and the first water layer (197.1g) was separated to obtain the first organic solution layer (1185.7g).
[0031] Add 12% sodium hypochlorite solution (118.6 g) to the first organic solution layer, the mass of which is 10% of the mass of the first organic solution layer, maintain the temperature at 85°C, keep stirring for 30 minutes, separate and remove the second water layer (119.8 g), and obtain the second organic solution layer (1184.0 g); Then, 10% of the mass of distilled water (118.4 g) was added to the second organic solution layer, the temperature was maintained at 85°C, and the mixture was stirred for 30 minutes. The third water layer (118.1 g) was separated and removed to obtain a third organic solution layer (1183.5 g). This was repeated three times to obtain a fourth organic solution layer (1182.9 g). The fourth organic solution layer was cooled to 4°C, filtered, and the solution (654.9 g) was removed to obtain a tetrabromobisphenol A wet cake (527.1 g). The tetrabromobisphenol A (426.9 g) was obtained by vacuum drying.
[0032] The yield of tetrabromobisphenol A in this example is 98.12%, and its purity is 99.91% as detected by liquid chromatography.
[0033] By using the method for synthesizing tetrabromobisphenol A based on phase transfer catalysis provided by the present invention, tetrabromobisphenol A is prepared, the bromination reaction time and the aging reaction time are greatly reduced, the yield of tetrabromobisphenol A is maintained between 97% and 98.5%, and the purity of tetrabromobisphenol A is greater than 99.8% as detected by liquid chromatography.
[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for synthesizing tetrabromobisphenol A based on phase transfer catalysis, characterized in that: The steps include: S100, sequentially add bisphenol A and hexadecyl diphenyl ether disulfonic acid to an organic solvent at a temperature of 20° C. to 28° C., stir, dropwise add hydrogen peroxide and bromine, react for 1.5 h to 2.5 h, and obtain a mixed solution; S200, stirring, heating the mixed solution to 80°C to 90°C, stirring for 0.5h to 1h, irradiating the mixed solution with ultrasound with an irradiation power of 40W to 60W for 15min to 30min, and after irradiation, standing for 15-30min, separating and removing the first water layer to obtain a first organic solution layer; S300, adding sodium nitrite solution to the first organic solution layer at a temperature of 80°C to 90°C, stirring for 0.5h to 1h, separating and removing the second water layer to obtain a second organic solution layer; S400, adding water to the second organic solution layer at a temperature of 80°C to 90°C, stirring for 0.5h to 1h, separating and removing the third water layer to obtain a third organic solution layer; S500, repeat step S400 2 to 4 times to obtain a fourth organic solution layer, cool it to 2°C to 6°C, filter it with suction, and dry it to obtain tetrabromobisphenol A.
2. The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis according to claim 1, characterized in that: In step S100, the preparation process of hexadecyl diphenyl ether disulfonic acid includes the following steps: S110, take C 16 The α-olefin and diphenyl ether undergo alkylation reaction under the catalysis of anhydrous aluminum chloride, the reaction temperature is 80℃~90℃, the reaction time is 4h~6h, and hexadecyl diphenyl ether is obtained; S120, using the hexadecyl diphenyl ether as a raw material, sulfur trioxide as a sulfonating agent, and urea as a cosolvent to prepare hexadecyl diphenyl ether disulfonic acid.
3. The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis as claimed in claim 2, characterized in that: In step S110, C 16 The molar ratio of the α-olefin to the added amount of diphenyl ether is 1:(1-1.2); in step S120, the molar ratio of hexadecyl diphenyl ether to sulfur trioxide is 1:(2-2.5).
4. The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis according to claim 1, characterized in that: In step S100, the organic solvent is one or more of chlorobenzene, ethyl acetate, propyl acetate, acetone, butanone, methanol, ethanol, and isopropanol.
5. The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis according to claim 1, characterized in that: In step S100, the molar ratio of bisphenol A, bromine and hydrogen peroxide added is 1: (2-2.2): (2.1-2.3).
6. The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis according to claim 1, characterized in that: In step S100, the mass of the added hexadecyl diphenyl oxide disulfonic acid is 0.7% to 1.1% of the mass of the added bisphenol A.
7. The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis according to claim 1, characterized in that: In step S100, the mass ratio of bisphenol A to the organic solvent added is 1:3 to 1:
5.
8. The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis according to claim 1, characterized in that: In step S200, the irradiation power is 45W to 55W.
9. The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis according to claim 1, characterized in that: In step S300, the mass concentration of the sodium nitrite solution is 10% to 14%, and the mass of the added sodium nitrite solution is 8% to 12% of the mass of the first organic solution layer.
10. The method for synthesizing tetrabromobisphenol A based on phase transfer catalysis according to claim 1, characterized in that: In step S400, the mass of water added is 8% to 12% of the mass of the second organic solution layer.