CN-121974774-A - Preparation process of brominated aromatic compound with uniform flame retardant efficiency

CN121974774ACN 121974774 ACN121974774 ACN 121974774ACN-121974774-A

Abstract

The application relates to the technical field of synthesis of flame retardants, and particularly discloses a preparation process of a brominated aromatic compound with uniform flame retardant efficiency. A process for preparing the bromoaromatic compound with uniform flame retarding efficiency includes such steps as adding bromine and catalyst to bromination reactor, dropping the molten diphenyl ethane to reactor, brominating reaction slurry containing decabromodiphenyl ethane, distilling for removing bromine to obtain slurry A, shaping to obtain slurry B, press filtering and washing to obtain primary wet filter cake, homogenizing to obtain slurry C, press filtering and washing to obtain secondary wet filter cake, drying to obtain coarse powder, passivating to obtain treated powder, sieving and pulverizing.

Inventors

YANG MINGHUI
SUN LIJUN
HAO JIANSHE
LI YUHAI
LI MIN

Assignees

寿光卫东腾冠化工有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. The preparation process of the brominated aromatic compound with uniform flame retardant efficiency is characterized by comprising the following steps of: adding bromine and a catalyst into a bromination kettle, starting stirring, and reducing the temperature in the kettle to 0-5 ℃, then slowly dripping melted diphenylethane into the reaction kettle, and after dripping, firstly preserving heat for 1.5 hours at 15 ℃ and then preserving heat for 2 hours at 25 ℃ to obtain reaction slurry containing decabromodiphenylethane, wherein the catalyst comprises iron powder; Distilling and debrominating, namely distilling and debrominating the reaction slurry containing decabromodiphenyl ethane to obtain a slurry A; shaping control, namely adding deionized water and a shaping agent into the slurry A, then reducing the temperature of the system A to 30-35 ℃, and statically aging for 1.5-2.5 hours at the temperature to obtain slurry B; primary filter pressing and washing, namely sending the slurry B into a filter press for solid-liquid separation, and washing a filter cake to obtain a primary wet filter cake; Homogenizing, namely transferring the primary wet filter cake into a sanding kettle, adding deionized water and a dispersing agent, adjusting the pH to 7.5-8.8, and performing sanding depolymerization by using zirconia beads to obtain slurry C; secondary filter pressing and washing, namely sending the slurry C into a filter press for solid-liquid separation, and washing a filter cake to obtain a secondary wet filter cake; drying, namely drying the secondary wet filter cake to obtain coarse powder of an intermediate product; Adding a silane coupling agent, polyethylene glycol and absolute ethyl alcohol into deionized water, stirring and mixing uniformly to obtain a treatment liquid, stirring coarse powder of an intermediate product, heating, spraying the treatment liquid, adding nano silicon dioxide, continuing mixing, and finally heating and volatilizing to obtain a treatment powder; crushing, namely sieving the treated powder, and then crushing to obtain the brominated aromatic compound.
2. The process for preparing a brominated aromatic compound having a uniform flame retardant efficiency as set forth in claim 1, wherein in said bromination reaction step, the mass ratio of diphenylethane to bromine is 1 (50-100), and the mass ratio of diphenylethane to catalyst is 23 (0.5-2).
3. The preparation process of the brominated aromatic compound with uniform flame retardant efficiency according to claim 1, wherein the distillation debromination step is characterized in that reaction slurry containing decabromodiphenyl ethane is transferred into a distillation kettle, low-temperature debromination is firstly carried out under the condition of minus 0.06MPa, the kettle temperature is controlled to be 35-55 ℃, excessive free bromine is distilled out, condensation and recovery are carried out, after the low-temperature debromination is finished, the temperature is raised to 60-65 ℃, deionized water is added, and distillation is continued for 1.5 hours, so that slurry A is obtained, wherein the weight ratio of the deionized water to the diphenyl ethane is 1.5:1.
4. The process for preparing a brominated aromatic compound having a uniform flame retardant efficiency as set forth in claim 1, wherein said shaping agent comprises sodium polyacrylate and has a weight ratio to diphenylethane of (0.1-0.6): 100 in said shaping control step.
5. The preparation process of brominated aromatic compound with uniform flame retardant efficiency according to claim 1, wherein the primary pressure filtration and washing steps are that slurry B is sent into a pressure filter for solid-liquid separation, and filter cake is washed to enable the pH value of filtrate to reach 4.5-6.5, thus obtaining primary wet filter cake.
6. The preparation process of the brominated aromatic compound with uniform flame retardant efficiency as set forth in claim 5, wherein in the homogenization treatment step, a primary wet filter cake is transferred into a sanding kettle, deionized water and a dispersing agent are added, the pH is regulated to 7.5 by sodium carbonate, and sanding depolymerization is carried out for 60min by using zirconia beads with the thickness of 0.6mm to obtain slurry C, wherein the dispersing agent comprises sodium hexametaphosphate, the weight ratio of the dispersing agent to the primary wet filter cake is (0.1-0.5): 100, and the weight ratio of the deionized water to the dispersing agent is 220:0.45.
7. The process for preparing brominated aromatic compound with uniform flame retardant efficiency according to claim 6, wherein the secondary filter pressing and washing comprises the steps of sending slurry C into a filter press for solid-liquid separation, and washing filter cakes to enable the pH value of the filtrate to reach 6.5-8.0, so as to obtain a secondary wet filter cake.
8. The process for preparing a brominated aromatic compound having uniform flame retardant efficiency as set forth in claim 1, wherein said drying step has a vacuum degree of-0.08 MPa, a drying temperature of 75 to 90℃and a time of 5 to 7 hours.
9. The preparation process of the brominated aromatic compound with uniform flame retardant efficiency according to claim 1 is characterized in that in the passivation treatment step, a silane coupling agent, polyethylene glycol and absolute ethyl alcohol are added into deionized water, stirring and mixing are carried out uniformly to obtain a treatment liquid, coarse powder of an intermediate product is stirred and heated to 50 ℃, then the treatment liquid is sprayed in the stirring process, nano silicon dioxide is added, mixing is continued for 25min, and finally the heat preservation is carried out for 1h at 60 ℃ to obtain a treatment powder, wherein the weight ratio of the silane coupling agent, the polyethylene glycol, the absolute ethyl alcohol and the deionized water in the treatment liquid is (0.4-0.5): (0.1-0.14): 8:3, the weight ratio of the silane coupling agent to the coarse powder of the intermediate product is (0.1-0.2): 100, and the weight ratio of the nano silicon dioxide to the coarse powder of the intermediate product is (0.1-0.3): 100.
10. The process for preparing the brominated aromatic compound with uniform flame retardant efficiency according to claim 1, wherein the crushing step is characterized in that the treated powder is sieved by a 40-60 mesh sieve and then subjected to jet milling to obtain the brominated aromatic compound, wherein the crushing medium is nitrogen, the pressure of the medium is 0.8MPa, and the feeding speed is 45kg/h.

Description

Preparation process of brominated aromatic compound with uniform flame retardant efficiency Technical Field The application relates to the technical field of synthesis of flame retardants, in particular to a preparation process of a brominated aromatic compound with uniform flame retardant efficiency. Background Decabromodiphenyl ethane is used as an important aromatic brominated flame retardant, has higher bromine content, better thermal stability and wider resin application range, and can be applied to styrene resin, engineering plastic and partial wire and cable materials. Compared with the traditional brominated flame retardant containing ether bond, the molecular structure of decabromodiphenyl ethane does not contain ether bond, and has better thermal stability in the high-temperature processing process, thus having higher industrial application value. The preparation of the prior decabromodiphenyl ethane generally comprises the steps of bromination reaction, distillation debromination, washing, drying, mechanical crushing and the like. However, the prior art often focuses more on whether the chemical reaction is sufficient, and the cooperative control of particle formation, particle deagglomeration, surface state, and final comminution process is inadequate. In particular, in the mechanical crushing stage, the powder is easy to agglomerate secondarily due to static electricity accumulation, so that the particle size distribution of the product is widened, coarse and fine particles coexist, and meanwhile, the problems of agglomeration and uneven dispersion are further aggravated due to insufficient front-end crystal shaping and unstable rear-end surface state. When the particle size distribution is wider and the agglomeration is more obvious, the dispersion uniformity of the flame retardant in the resin matrix is poorer, and the conditions of local flame retardant enrichment and local flame retardant shortage are easy to occur, so that the flame retardant efficiency fluctuation among different parts of the same batch of products or the same product is caused, and the flame retardant performance, the processing stability and the batch consistency are difficult to consider. Therefore, how to improve the uniformity of the particle size distribution of the product, inhibit agglomeration and improve the stability of the flame retardant efficiency through a process path on the premise of not changing the basic flame retardant mechanism of decabromodiphenylethane becomes a technical problem to be solved in the field. Disclosure of Invention In order to improve the uniformity of the particle size distribution of the product and further improve the flame retardant efficiency, the application provides a preparation process of a brominated aromatic compound with uniform flame retardant efficiency. The application provides a preparation process of a brominated aromatic compound with uniform flame retardant efficiency, which adopts the following technical scheme: a preparation process of brominated aromatic compound with uniform flame retardant efficiency comprises the following steps: Adding bromine and a catalyst into a bromination kettle, starting stirring, and reducing the temperature in the kettle to 0-5 ℃, then slowly dripping melted diphenylethane into the reaction kettle, and continuing to perform heat preservation reaction after dripping, wherein the heat preservation is firstly performed for 1.5 hours at 15 ℃ and then the heat preservation is performed for 2 hours at 25 ℃ to obtain reaction slurry containing decabromodiphenylethane, and the catalyst comprises iron powder; Distilling and debrominating, namely distilling and debrominating the reaction slurry containing decabromodiphenyl ethane to obtain a slurry A; shaping control, namely adding deionized water and a shaping agent into the slurry A, then reducing the temperature of the system A to 30-35 ℃, and statically aging for 1.5-2.5 hours at the temperature to obtain slurry B; primary filter pressing and washing, namely sending the slurry B into a filter press for solid-liquid separation, and washing a filter cake to obtain a primary wet filter cake; Homogenizing, namely transferring the primary wet filter cake into a sanding kettle, adding deionized water and a dispersing agent, adjusting the pH to 7.5-8.8, and performing sanding depolymerization by using zirconia beads to obtain slurry C; secondary filter pressing and washing, namely sending the slurry C into a filter press for solid-liquid separation, and washing a filter cake to obtain a secondary wet filter cake; drying, namely drying the secondary wet filter cake to obtain coarse powder of an intermediate product; Adding a silane coupling agent, polyethylene glycol and absolute ethyl alcohol into deionized water, stirring and mixing uniformly to obtain a treatment liquid, stirring coarse powder of an intermediate product, heating, spraying the treatment liquid, adding nano silicon dioxide, conti