Preparation method of tetrabromobisphenol A diglycidyl ether

Abstract

The invention relates to the technical field of flame-retardant resin synthesis, in particular to a preparation method of tetrabromobisphenol A diglycidyl ether, which comprises the following steps: under the action of a catalyst, carrying out ring-opening reaction on tetrabromobisphenol A and an epoxy group of epoxy chloropropane to generate a compound of which the end group is chlorohydrin ether, then removing HCl from the chlorohydrin ether, and carrying out ring-closing reaction to obtain the tetrabromobisphenol A diglycidyl ether. According to the technical scheme, the using amount of epoxy chloropropane and tetrabromobisphenol A is 1.02-1.25 times of the theoretical value, the using amount of epoxy chloropropane and generation of by-products are greatly reduced, and the high-purity and high-yield tetrabromobisphenol A diglycidyl ether monomer can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of flame retardant resin synthesis, in particular to a method for preparing tetrabromobisphenol A diglycidyl ether. Background Art

[0002] Brominated flame retardants have become one of the world's largest-production, most efficient and most widely used flame retardants, with the characteristics of high flame retardant efficiency and low dosage. More importantly, their decomposition temperature can match the decomposition temperature of most polymer materials, and their comprehensive performance is even better. Brominated epoxy resin, as one of the new polymer-based brominated flame retardants, has excellent intrinsic flame retardancy, adhesion and thermal stability, and has the advantages of low toxicity, low price and safe use. It has been widely used in flame retardant fields such as PBT, PC, PET, Nylon, PC / PBT and PET / ABS alloys.

[0003] Tetrabromobisphenol A diglycidyl ether is an important brominated epoxy resin and also the core raw material for synthesizing higher molecular weight brominated epoxy resin flame retardants. Although the synthesis of this monomer has been extensively studied, this substance is extremely unstable under the action of a strong alkaline catalyst during the synthesis process, and is prone to produce a large amount of by-products and brominated epoxy resins of different molecular weights. The structure is uncontrollable, and it is impossible to obtain polymerization-grade, high-purity tetrabromobisphenol A diglycidyl ether monomers, making it difficult to achieve the synthesis of high molecular weight brominated epoxy resins. Summary of the invention

[0004] The invention aims to provide a method for preparing tetrabromobisphenol A diglycidyl ether, which greatly reduces the amount of epichlorohydrin used and the generation of by-products, and obtains tetrabromobisphenol A diglycidyl ether monomer with high purity and high yield.

[0005] The above technical purpose of the present invention is achieved through the following technical scheme: a method for preparing tetrabromobisphenol A diglycidyl ether, comprising the following raw materials in parts by weight: 290-310 parts of tetrabromobisphenol A, 90-100 parts of epichlorohydrin, 3.5-6.8 parts of catalyst, 0.35-0.85 parts of surfactant, 230-500 parts of organic solvent, 3-5 parts of activated carbon, and 20-45 parts of NaOH solution.

[0006] As a further configuration of the present invention, a method for preparing tetrabromobisphenol A diglycidyl ether is prepared by the following steps:

[0007] S1: Under the action of a catalyst, tetrabromobisphenol A and epichlorohydrin first undergo a ring-opening reaction to generate a compound with a chlorohydrin ether terminal group;

[0008] S2: removing HCl from the chlorohydrin ether terminal compound prepared in step 1, and performing a ring-closing reaction to generate tetrabromobisphenol A diglycidyl ether monomer.

[0009] The present invention prepares tetrabromobisphenol A diglycidyl ether through a two-step reaction, and the reaction equation is as follows:

[0010] The first step of the reaction:

[0011]

[0012] Second step of reaction:

[0013]

[0014] Under the action of a catalyst, tetrabromobisphenol A and the epoxy group of epichlorohydrin first undergo a ring-opening reaction to generate a compound with a terminal chlorohydrin ether. Then, the chlorohydrin ether removes HCl and undergoes a ring-closing reaction to generate a tetrabromobisphenol A diglycidyl ether monomer. In order to ensure the smoothness of the reaction, a sodium hydroxide component is added, which immediately reacts with the HCl just removed to generate NaCl, thereby ensuring the smooth progress of the reaction.

[0015] As a further configuration of the present invention, the specific preparation method of step S1 is: under nitrogen protection, 290-310 parts of tetrabromobisphenol A are added to 90-100 parts of epichlorohydrin, 0.35-0.85 parts of a surfactant and 100 parts of an organic solvent, the temperature is controlled at 60-70°C for stirring, and 3.5-6.8 parts of a catalyst are added, stirring is continued for 15-30 minutes, the temperature is controlled at 95-120°C, and the reaction is carried out for 2-3 hours.

[0016] As a further configuration of the present invention, the specific preparation method of step S2 is: pouring the reaction product obtained in step S1 into a reaction bottle, adding 130-400 parts of an organic solvent, controlling the temperature at 50-65°C, and dripping 20-45 parts of a 20%-40% NaOH solution into the reaction bottle, and reacting for 3-5 hours; after the reaction is completed, adding 3-5 parts of activated carbon, continuing to stir for 15-30 minutes, filtering, collecting the filtrate, allowing the filtrate to stand and stratify, cutting off the aqueous phase, and retaining the organic phase containing tetrabromobisphenol A diglycidyl ether monomer.

[0017] As a further configuration of the present invention, the organic phase containing tetrabromobisphenol A diglycidyl ether monomer obtained in step S2 is washed and impurities are removed by a process of "acid neutralization + water washing".

[0018] As a further configuration of the present invention, the "acid neutralization and water washing" process includes the following steps: adding the organic phase containing tetrabromobisphenol A diglycidyl ether monomer obtained in step S2 to a three-necked flask, adding 100-260 parts of a 20-35% acidic aqueous solution at room temperature, stirring for 10-30 minutes, neutralizing the system to a pH of 6-7, adding 300-600 mL of deionized water at 70-80°C, stirring for 10-30 minutes, retaining the organic phase, repeating the operation, and washing the organic phase 1-3 times; adding 5-20 parts of anhydrous magnesium sulfate to the organic phase collected in the "acid neutralization + water washing" process, leaving it at room temperature for 48 hours, filtering, and performing reduced pressure distillation on the filtrate, and drying the obtained product in a vacuum oven at 50°C for 24 hours to obtain tetrabromobisphenol A diglycidyl ether.

[0019] As a further configuration of the present invention, the reaction bottle of step S2 is provided with a nitrogen flow inlet and an outlet. The nitrogen flow inlet tube adopts a glass tube with an inner wall of 5 mm, which is directly inserted into the bottom end of the reaction bottle, and the outlet is connected to the alkali solution absorption device. The nitrogen flow is 10-15 ml / min to ensure that bubbles are continuously bubbling out; after the reaction is completed, the nitrogen tube is removed and activated carbon is added to continue the reaction.

[0020] As a further configuration of the present invention, the catalyst is one or more of 20%-40% concentration of ammonia water, potassium bicarbonate, sodium bicarbonate, sodium sulfite, sodium bisulfite, potassium bisulfite and potassium sulfite.

[0021] As a further configuration of the present invention, the organic solvent is one or more of toluene, xylene, methyl isobutyl ketone, carbon tetrachloride, 1,2-dichloroethane, chloroform and dichloromethane.

[0022] As a further configuration of the present invention, the acidic aqueous solution is one or more of phosphoric acid, hydrochloric acid, acetic acid, sodium dihydrogen phosphate, and potassium dihydrogen phosphate with a concentration of 20-35%.

[0023] As a further configuration of the present invention, the surfactant is preferably one of sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, tetrabutylammonium bromide and hexadecyltrimethylammonium bromide.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. In order to improve the reaction yield, the material is usually prepared by reacting a large amount of excess epichlorohydrin with tetrabromobisphenol A, and then recovering the excess epichlorohydrin. The amount of epichlorohydrin used is 7-10 times higher than the theoretical value. The problem with this solution is that a large amount of epichlorohydrin is hydrolyzed to generate a large amount of 3-chloro-1,2-propylene glycol as a by-product (Equation 2). Although the yield is improved, the large amount of by-products makes subsequent purification very difficult, the epoxy equivalent of the obtained product increases, and a high-purity target product cannot be obtained.

[0026]

[0027] In the technical solution, the dosage of epichlorohydrin and tetrabromobisphenol A is 1.02-1.25 times of the theoretical value, which greatly reduces the dosage of epichlorohydrin and the generation of by-products, and can obtain a monomer with high purity and high yield.

[0028] 2. In the first step of the reaction, the present technical solution uses a weakly alkaline catalyst instead of the traditional sodium hydroxide strong alkaline catalyst. The solution avoids the severe hydrolysis of epichlorohydrin in a strong alkaline environment, reduces the generation of by-products, and improves the utilization rate of epichlorohydrin. However, the weakly alkaline catalyst will reduce the catalytic efficiency, reduce the reaction yield, and prolong the reaction time. In order to solve this problem, a surfactant component is added to the present solution, so that the catalyst and tetrabromobisphenol A phenol anion in the aqueous phase can be fully mixed with the epichlorohydrin component present in the organic phase, thereby improving the reaction yield; and the weakly alkaline catalyst can avoid the first step of the closed-loop reaction, thereby eliminating the possibility of tetrabromobisphenol A and epoxy groups further generating high molecular weight resins. The weak base ensures that the obtained chlorohydrin ether cannot complete the closed-loop reaction, thereby controlling the generation of epoxy end groups and solving the problem; at the same time, the addition of the surfactant allows the first step to completely open the ring to generate alcohol ether compounds, thereby improving the utilization rate of epichlorohydrin and improving the yield.

[0029] 3. In the second step of the preparation of the target product, hydrogen chloride gas will be produced. This by-product needs to be disposed of as soon as possible to ensure the smooth progress of the reaction. The technical solution adopts a combination of two methods to solve this problem. The first is to add alkaline sodium hydroxide, and the generated hydrogen chloride is directly generated by neutralization reaction to generate sodium chloride to consume the generated hydrogen chloride gas. The second is to use nitrogen bubbling method to directly take the hydrogen chloride gas that has not been neutralized by sodium hydroxide out of the reaction system and dispose of it through the alkali solution absorption device outside the reaction bottle. These two methods ensure that the generated hydrogen chloride by-product is consumed in time, thereby ensuring the smooth progress of the reaction. Due to the addition of a nitrogen gas flow to derive hydrogen chloride gas, the amount of sodium hydroxide added is reduced by 35-40%, greatly reducing the post-processing cost. In the reaction process, due to various factors such as benzene ring structure and oxidation, the product will have a certain color. A small amount of activated carbon is added in the technical solution, and the color of the product is well improved through activated carbon adsorption.

[0030] 4. In the second step, the aqueous phase is cut off and the organic phase is retained. In the third step, although a large amount of strong sodium oxide and sodium chloride have been separated, there are still residues. In the third step post-processing process, this technical solution adopts the "acid neutralization + water washing" process. The strong base sodium hydroxide added in the second step reaction will remain in the system in large quantities, and the pH value reaches 12-13. If it is directly washed with water, a large amount of water is required for 8-12 times of multiple washings, and it is difficult to wash it clean, which not only wastes water resources, but also has high post-processing costs and causes monomer loss. The salt in the system can be washed clean by first neutralizing the alkali in the system with acid to generate water-soluble salts, and then simply washing with water; this technical solution not only reduces the amount of wastewater, but also reduces the product loss caused by multiple washings.

[0031] 5. The technical solution of the present invention greatly reduces the amount of epichlorohydrin used by adding surfactants, exhausting hydrogen chloride byproducts with nitrogen gas flow, and using weakly alkaline catalysts. The amount of epichlorohydrin used is reduced from 7-10 times of the traditional solution to 1.02-1.25 times, and the purity is as high as 93.3%, which is much higher than the current purity of 75%, and the yield is 92.4-93.3%, which is higher than the 42.5% of the traditional solution. Moreover, the operation is simpler and more convenient, and it is easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 , HPLC spectrum of the product of Example 1;

[0034] Figure 2 , the HPLC peak integrated area of ​​Example 1;

[0035] Figure 3 , HPLC spectrum of the product of Example 2;

[0036] Figure 4 , the HPLC peak integrated area of ​​Example 2;

[0037] Figure 5 , HPLC spectrum of the product of Example 3;

[0038] Figure 6 , the HPLC peak integrated area of ​​Example 3;

[0039] Figure 7 , HPLC spectrum of the product of Comparative Example 1;

[0040] Figure 8 , HPLC peak integrated area of ​​Comparative Example 1;

[0041] Fig. 9 , HPLC spectrum of the product of Comparative Example 2;

[0042] Fig.10 , HPLC peak integrated area of ​​Comparative Example 2. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments are described clearly and completely below. 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.

[0044] Example 1. Preparation of Tetrabromobisphenol A Diglycidyl Ether

[0045] Step 1: Under nitrogen protection, add 271.8 g of tetrabromobisphenol A to 110.8 g of epichlorohydrin, 0.35 g of sodium dodecylbenzene sulfonate and 100 g of toluene, control the temperature at 60°C, stir into one phase, add 3.5 g of 40% ammonia solution, continue stirring for 30 minutes, control the temperature at 95°C, and react for 3 hours.

[0046] Step 2: introduce the product of the first step reaction into the second reaction bottle, add 130g of toluene, control the temperature at 50°C, drop 20g of 40% NaOH solution into the reaction bottle, and react for 5h. During the reaction, nitrogen gas flows through the nitrogen tube, and the generated HCl gas is introduced into the alkali solution absorption device at a gas flow rate of 10ml / min. After the reaction, add 3g of activated carbon, continue stirring for 15min, filter, collect the filtrate, let the filtrate stand and separate, cut off the aqueous phase, and retain the organic phase.

[0047] Step 3: Add the organic phase obtained in the second step into a three-necked flask, add 100 g of 35% phosphoric acid at room temperature, stir for 10 min, neutralize the system to pH = 6, add 300 ml of 70°C deionized water, stir for 30 min, cut off the aqueous phase, retain the organic phase, repeat the operation, and wash the organic phase once.

[0048] Step 4: add 5 g of anhydrous magnesium sulfate to the collected organic phase, place at room temperature for 48 hours, filter, and distill the filtrate under reduced pressure. Dry the obtained product in a vacuum oven at 50°C for 24 hours to obtain the product.

[0049] Example 2: Preparation of Tetrabromobisphenol A Diglycidyl Ether

[0050] Step 1: Under nitrogen protection, add 462.5 g of tetrabromobisphenol A to 235.9 g of epichlorohydrin, 0.85 g of sodium dodecyl sulfate and 450 g of xylene, control the temperature at 70°C, stir into one phase, add 6.8 g of 20% potassium bicarbonate solution, continue stirring for 15 minutes, control the temperature at 120°C, and react for 2 hours.

[0051] Step 2: introduce the reaction product of the first step into the second reaction bottle, add 400g of xylene, control the temperature at 65°C, drop 45g of 20% NaOH solution into the reaction bottle, and react for 3h. During the reaction, nitrogen gas flows through the nitrogen tube to introduce the generated HCl gas into the alkali solution absorption device at a flow rate of 12ml / min. After the reaction, add 5g of activated carbon, continue stirring for 30min, filter, collect the filtrate, let the filtrate stand and separate, cut off the aqueous phase, and retain the organic phase.

[0052] Step 3: Add the organic phase obtained in the second step into a three-necked flask, add 260 g of 20% acetic acid aqueous solution at room temperature, stir for 30 min, neutralize the system to pH = 7, add 600 ml of 80°C deionized water, stir for 10 min, cut off the aqueous phase, retain the organic phase, repeat this operation, and wash the organic phase twice.

[0053] Step 4: add 20 g of anhydrous magnesium sulfate to the collected organic phase, leave it at room temperature for 48 hours, filter, and distill the filtrate under reduced pressure. Dry the obtained product in a vacuum oven at 50° C. for 24 hours to obtain the product.

[0054] Example 3: Preparation of Tetrabromobisphenol A Diglycidyl Ether

[0055] Step 1: Under nitrogen protection, add 408.2 g of tetrabromobisphenol A to 145.7 g of epichlorohydrin, 0.45 g of tetrabutylammonium bromide and 510 g of methyl isobutyl ketone, control the temperature at 65°C, stir into one phase, add 4.1 g of 30% sodium bicarbonate solution, continue stirring for 20 minutes, control the temperature at 100°C, and react for 2.5 hours.

[0056] Step 2: introduce the reaction product of the first step into the second reaction bottle, add 310g of methyl isobutyl ketone, control the temperature at 55°C, drop 25g of 30% NaOH solution into the reaction bottle, and react for 3.5h. During the reaction, nitrogen gas flows through the nitrogen tube to introduce the generated HCl gas into the alkali solution absorption device at a gas flow rate of 13ml / min. After the reaction, add 4g of activated carbon, continue stirring for 20min, filter, collect the filtrate, let the filtrate stand and separate, cut off the aqueous phase, and retain the organic phase.

[0057] Step 3: Add the organic phase obtained in the second step into a three-necked flask, add 150 g of 30% hydrochloric acid at room temperature, stir for 20 min, neutralize the system to pH = 6.5, add 400 ml of 75°C deionized water, stir for 15 min, cut off the aqueous phase, retain the organic phase, repeat the operation, and wash the organic phase once.

[0058] Step 4: add 15 g of anhydrous magnesium sulfate to the collected organic phase, leave it at room temperature for 48 hours, filter, and distill the filtrate under reduced pressure. Dry the obtained product in a vacuum oven at 50° C. for 24 hours to obtain the product.

[0059] Example 4. Preparation of Tetrabromobisphenol A Diglycidyl Ether

[0060] Step 1: Under nitrogen protection, add 353.6 g of tetrabromobisphenol A to 135.5 g of epichlorohydrin, 0.55 g of hexadecyltrimethylammonium bromide and 350 g of carbon tetrachloride, control the temperature at 63 ° C, stir into one phase, add 5.1 g of 35% sodium sulfite solution, continue stirring for 25 minutes, control the temperature at 105 ° C, and react for 2 hours.

[0061] Step 2: introduce the product of the first step reaction into the second reaction bottle, add 220g of carbon tetrachloride, control the temperature at 58°C, drop 35g of 25% NaOH solution into the reaction bottle, and react for 4.5h. During the reaction, nitrogen gas flows through the nitrogen tube, and the generated HCl gas is introduced into the alkali solution absorption device at a gas flow rate of 15ml / min. After the reaction, add 4.5g of activated carbon, continue stirring for 20min, filter, collect the filtrate, let the filtrate stand and separate, cut off the aqueous phase, and retain the organic phase.

[0062] Step 3: Add the organic phase obtained in the second step into a three-necked flask, add 320 g of 20% potassium dihydrogen phosphate aqueous solution at room temperature, stir for 22 min, neutralize the system to pH = 6.8, add 450 ml of 78°C deionized water, stir for 15 min, cut off the aqueous phase, retain the organic phase, repeat the operation, and wash the organic phase twice.

[0063] Step 4: add 15 g of anhydrous magnesium sulfate to the collected organic phase, leave it at room temperature for 48 hours, filter, and distill the filtrate under reduced pressure. Dry the obtained product in a vacuum oven at 50° C. for 24 hours to obtain the product.

[0064] Example 5. Preparation of Tetrabromobisphenol A Diglycidyl Ether

[0065] Step 1: Under nitrogen protection, add 244.8 g of tetrabromobisphenol A to 104.5 g of epichlorohydrin, 0.65 g of tetrabutylammonium bromide and 160 g of 1,2-dichloroethane, control the temperature at 60°C, stir into one phase, add 4.7 g of 30% sodium bisulfite solution, continue stirring for 26 minutes, control the temperature at 115°C, and react for 2.5 hours.

[0066] Step 2: introduce the product of the first step reaction into the second reaction bottle, add 350g of 1,2-dichloroethane, control the temperature at 60°C, drop 40g of 35% NaOH solution into the reaction bottle, and react for 3h. During the reaction, nitrogen gas flows through the nitrogen tube, and the generated HCl gas is introduced into the alkali solution absorption device at a gas flow rate of 10ml / min. After the reaction, add 4.5g of activated carbon, continue stirring for 20min, filter, collect the filtrate, let the filtrate stand and stratify, cut off the aqueous phase, and retain the organic phase.

[0067] Step 3: Add the organic phase obtained in the second step into a three-necked flask, add 180 g of 28% hydrochloric acid aqueous solution at room temperature, stir for 25 min, neutralize the system to pH = 6, add 550 ml of 75°C deionized water, stir for 20 min, cut off the aqueous phase, retain the organic phase, repeat this operation, and wash the organic phase 3 times.

[0068] Step 4: add 15 g of anhydrous magnesium sulfate to the collected organic phase, leave it at room temperature for 48 hours, filter, and distill the filtrate under reduced pressure. Dry the obtained product in a vacuum oven at 50° C. for 24 hours to obtain the product.

[0069] Comparative Example 1 Preparation of Tetrabromobisphenol A Diglycidyl Ether

[0070] The preparation was carried out according to the synthesis method of Example 1, except that sodium dodecylbenzenesulfonate was omitted and the other ingredients remained unchanged.

[0071] Comparative Example 2: Preparation of Tetrabromobisphenol A Diglycidyl Ether

[0072] The preparation was carried out according to the synthesis method of Example 1, except that sodium dodecylbenzene sulfonate was eliminated, the 40% ammonia solution was replaced with a 40% sodium hydroxide solution, and the other contents remained unchanged.

[0073] Comparative Example 3: Preparation of Tetrabromobisphenol A Diglycidyl Ether

[0074] The preparation was carried out according to the synthesis method of Example 1, except that sodium dodecylbenzene sulfonate was eliminated, the 40% ammonia solution was replaced with a 40% sodium hydroxide solution, and the nitrogen gas flow was eliminated to remove the HCl gas process, and the other steps remained unchanged. This technical solution is the current traditional synthesis technical solution.

[0075] Table 1. Test results of Examples 1-5 and Comparative Examples 1-3

[0076]

[0077] Compared with Example 1, Comparative Example 1 cancels the surfactant, and it is found that the yield is lower and the purity is lower. The reason is that the reaction raw materials are in two phases respectively, epichlorohydrin is in the organic phase toluene, and tetrabromobisphenol A phenol oxygen anion and catalyst are in the aqueous phase. There is no surfactant, which belongs to an interfacial reaction, and the reaction efficiency is low, so the yield is lower. Although the yield is low, because it is a weak base, there are few by-products and the purity is still high. Compared with Example 1, Comparative Example 2 cancels the surfactant, but the weak alkaline ammonia catalyst is changed to sodium hydroxide, so the yield is still improved to a certain extent compared with Comparative Example 1, but because it is a strong alkaline catalyst, there are more by-products and the purity is lower. Compared with Example 1, Comparative Example 3 cancels the surfactant, cancels the nitrogen gas flow, and the weak alkaline ammonia catalyst is changed to sodium hydroxide, compared with Comparative Example 2, the hydrogen chloride gas generated in the system still has a small amount of residue, so the yield and purity are all lower than Comparative Example 2.

[0078] The HPLC peak of the target product tetrabromobisphenol A diglycidyl ether is the peak corresponding to the retention time of 9.6-9.8 min. It can be seen from the HPLC spectra of Examples 1 to 3 of the present invention that there is only one main peak and the other peaks are very small. It can be seen from the results of Tables 1 to 3 that the peak areas of the main peaks appearing at the retention times are 91.32%, 93.06% and 93.08%, respectively, and the purity of all the target products exceeds 91%.

[0079] From the HPLC spectrum of Comparative Example 1, it can be seen that in addition to the target product peak appearing at the retention time of 9.8 min, another peak appeared at the retention time of 37.8 min, and from the corresponding peak area results, it can be seen that the area of ​​the main peak is 63.96%. From the HPLC spectrum of Comparative Example 2, it can be seen that in addition to the target product peak appearing at the retention time of 9.8 min, two groups of peaks also appeared at retention times of 37.9 min and 46.7 min. From the corresponding peak area results, it can be seen that the peak areas are 25.84%, 61.19% and 8.81%, respectively. This result shows that the purity is only 25.84%, and there are a large number of by-products.

Claims

1. A method for preparing tetrabromobisphenol A diglycidyl ether, characterized in that: The invention comprises the following raw materials in parts by weight: 290-310 parts of tetrabromobisphenol A, 90-100 parts of epichlorohydrin, 3.5-6.8 parts of catalyst, 0.35-0.85 parts of surfactant, 230-500 parts of organic solvent, 3-5 parts of activated carbon and 20-45 parts of NaOH solution.

2. The method for preparing tetrabromobisphenol A diglycidyl ether according to claim 1, characterized in that: Prepared by the following steps: S1: Under the action of a catalyst, tetrabromobisphenol A and epichlorohydrin first undergo a ring-opening reaction to generate a compound with a chlorohydrin ether terminal group; S2: removing HCl from the chlorohydrin ether terminal compound prepared in step 1, and performing a ring-closing reaction to generate tetrabromobisphenol A diglycidyl ether monomer.

3. The method for preparing tetrabromobisphenol A diglycidyl ether according to claim 2, characterized in that: The specific preparation method of step S1 is: under nitrogen protection, 290-310 parts of tetrabromobisphenol A are added to 90-100 parts of epichlorohydrin, 0.35-0.85 parts of surfactant and 100 parts of organic solvent, the temperature is controlled at 60-70°C for stirring, and 3.5-6.8 parts of catalyst are added, stirring is continued for 15-30 minutes, the temperature is controlled at 95-120°C, and the reaction is carried out for 2-3 hours.

4. The method for preparing tetrabromobisphenol A diglycidyl ether according to claim 2, characterized in that: The specific preparation method of step S2 is as follows: pour the reaction product obtained in step S1 into a reaction bottle, add 130-400 parts of an organic solvent, control the temperature at 50-65° C., drop 20-45 parts of a 20%-40% NaOH solution into the reaction bottle, and react for 3-5 hours; after the reaction is completed, add 3-5 parts of activated carbon, continue stirring for 15-30 minutes, filter, collect the filtrate, let the filtrate stand and separate, cut off the aqueous phase, and retain the organic phase containing tetrabromobisphenol A diglycidyl ether monomer.

5. The method for preparing tetrabromobisphenol A diglycidyl ether according to claim 4, characterized in that: The organic phase containing tetrabromobisphenol A diglycidyl ether monomer obtained in step S2 is washed and impurities are removed by the process of "acid neutralization + water washing".

6. The method for preparing tetrabromobisphenol A diglycidyl ether according to claim 5, characterized in that: The "acid neutralization + water washing" process comprises the following steps: adding the organic phase containing tetrabromobisphenol A diglycidyl ether monomer obtained in step S2 into a three-necked flask, adding 100-260 parts of a 20-35% acidic aqueous solution at room temperature, stirring for 10-30 minutes, neutralizing the system to a pH of 6-7, adding 300-600 mL of deionized water at 70-80° C., stirring for 10-30 minutes, retaining the organic phase, repeating the operation, and washing the organic phase 1-3 times; adding 5-20 parts of anhydrous magnesium sulfate to the organic phase collected in the "acid neutralization + water washing" process, leaving it at room temperature for 48 hours, filtering, and performing reduced pressure distillation on the filtrate, and drying the obtained product in a vacuum oven at 50° C. for 24 hours to obtain tetrabromobisphenol A diglycidyl ether.

7. The method for preparing tetrabromobisphenol A diglycidyl ether according to claim 4, characterized in that: The reaction bottle in step S2 is provided with a nitrogen flow inlet and an outlet. The nitrogen flow inlet tube adopts a glass tube with an inner wall of 5 mm, which is directly inserted into the bottom of the reaction bottle, and the outlet is connected to the alkali solution absorption device. The nitrogen flow is 10-15 ml / min to ensure that bubbles are continuously bubbling out; after the reaction is completed, the nitrogen tube is removed and activated carbon is added to continue the reaction.

8. The method for preparing tetrabromobisphenol A diglycidyl ether according to claim 1, characterized in that: The catalyst is one or more of 20%-40% concentration of ammonia water, potassium bicarbonate, sodium bicarbonate, sodium sulfite, sodium bisulfite, potassium bisulfite and potassium sulfite.

9. The method for preparing tetrabromobisphenol A diglycidyl ether according to claim 1, characterized in that: The organic solvent is one or more of toluene, xylene, methyl isobutyl ketone, carbon tetrachloride, 1,2-dichloroethane, chloroform and dichloromethane.

10. The method for preparing tetrabromobisphenol A diglycidyl ether according to claim 1, characterized in that: The acidic aqueous solution is one or more of phosphoric acid, hydrochloric acid, acetic acid, sodium dihydrogen phosphate, and potassium dihydrogen phosphate with a concentration of 20-35%.

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