CN115572268B

CN115572268B - Method for continuously synthesizing diallyl isocyanurate

Info

Publication number: CN115572268B
Application number: CN202211471125.3A
Authority: CN
Inventors: 邱鹏云; 熊然; 刘林波
Original assignee: Hunan Fangruida New Materials Co ltd
Current assignee: Hunan Fangruida New Materials Co ltd
Priority date: 2022-11-23
Filing date: 2022-11-23
Publication date: 2023-03-10
Anticipated expiration: 2042-11-23
Also published as: CN115572268A

Abstract

The invention discloses a method for continuously synthesizing diallyl isocyanurate, and belongs to the technical field of organic synthesis processes. The method comprises the following specific steps: continuously adding an o-xylene solution of triallyl cyanurate and an aqueous solution of copper acetate into a tubular reactor with axial stirring through a metering pump respectively for reaction; then the mixture enters a tubular cooling crystallizer with axial stirring for cooling crystallization; and then carrying out solid-liquid separation by centrifugation, wherein the solid is the crude product of the diallyl isocyanurate. The invention solves the defect of concentrated release of reaction heat in the prior art; the reaction temperature is high, the mixing is sufficient, the reaction time is reduced, the influence of high temperature on materials for a long time is avoided, the generation of byproducts such as the allyl isocyanurate is reduced, the product quality and the yield are improved, the product quality of different batches is stable, and the method has important significance for industrial production.

Description

Method for continuously synthesizing diallyl isocyanurate

Technical Field

The invention belongs to the technical field of organic synthesis, and relates to a preparation method of diallyl isocyanurate.

Background

Diallyl isocyanurate (1,3-Diallyl-1,3,5-triazazine-2,4,6-trione, hereinafter referred to as DTT) with the chemical name 1,3-Diallyl-1,3,5-triazine-2,4,6-trione as white crystals or powder at room temperature. Melting point: 145-146 ℃, molecular formula: c ₉ H ₁₁ N ₃ O ₃ Molecular weight: 209.20, structural formula:

DTT is a multifunctional olefin monomer containing aromatic heterocyclic rings, and has excellent chemical stability and thermal stability due to the existence of stable triazine rings in the product structure of DTT. And the two allyl groups have strong reactivity and can easily react with the bromine to form one of the organic flame retardants with the largest yield in the world, namely the brominated flame retardant. DTT can also be used for modifying epoxy resin or used as a radiation crosslinking sensitizer such as triallyl isocyanurate and the like and a main intermediate of hapten such as tris (2,3-dibromopropyl) isocyanurate and the like. DTT is a novel polymer material auxiliary agent with wide application, and plays an important role in polymer synthesis.

The synthesis of DTT is largely divided into two classes. One is a route using cyanuric acid as raw material, for example CN104628665A discloses a cyanuric acid trisodium salt obtained by reacting cyanuric acid with sodium hydroxide reacts with allyl bromide, the method has complex process and long reaction period, and allyl bromide is easy to hydrolyze and return toThe recycling is difficult, and the industrial production is difficult to realize; in addition, the product contains a cyanuric acid trisubstituted or monosubstituted byproduct, and the subsequent purification difficulty is high, so that the purity of the DTT product is low. The other is a route which does not directly use cyanuric acid as a raw material, but uses triallyl cyanurate in Cu ²⁺ Diallyl isocyanurate is prepared by rearrangement under catalysis and high temperature. Such as Likhterov (Likhterov VR, klenovich SV, etlis VS, et al, inter-and intramolecular characterization of tertiary cells [ J]Khimiya Geterotsikh Soedinenii, 1988 (3), 376-9.) adding triallyl cyanurate and copper chloride to the reactor in one portion, during the heating process, there will be by-products such as monoallyl isocyanurate; moreover, according to the method, during industrial production, reaction heat in the reaction kettle is difficult to remove, so that the danger of reaction runaway exists, and safety accidents such as material flushing and the like are easily caused. In order to solve the defect that the reaction heat is difficult to remove, JP 2016216399A adds triallyl cyanurate to a reaction kettle in batches, although the occurrence of a material flushing accident can be avoided by controlling the amount and the speed of adding triallyl cyanurate in batches, the temperature control effect is still poor, the reaction time is prolonged, and the material is influenced by high temperature for a long time, so that the byproduct of the allyl isocyanurate is increased, and the color of the product is dark.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects of the prior art and provides a method for continuously preparing diallyl isocyanurate, which has high reaction selectivity and high purity of the obtained product. The method can solve the problems that the reaction heat is difficult to remove, the reaction temperature is out of control and even material flushing is caused in the prior art, the material is prevented from being influenced by high temperature for a long time, the generation of byproducts such as allyl isocyanurate is reduced, and the product quality is improved. The method adopts a tubular reactor with axial stirring as a reactor, and synchronously adds the o-xylene solution of triallyl cyanurate and the copper acetate aqueous solution in the reactor, thereby realizing a full-mixing and horizontal-pushing reaction mode, solving the defects of concentrated release of reaction heat and difficult removal, accelerating the reaction speed, avoiding the influence of high temperature on materials for a long time, reducing the generation of byproducts such as monoallyl isocyanurate and the like, and having good product quality and high yield.

In order to solve the technical problems, the invention adopts the following technical scheme:

continuously adding an o-xylene solution of triallyl cyanurate and an aqueous solution of copper acetate into a tubular reactor with axial stirring for reaction through two metering pumps respectively; then the material enters a tubular cooling crystallizer with axial stirring for cooling crystallization; carrying out centrifugal solid-liquid separation on the crystallized material, wherein the solid is a crude product of the diallyl isocyanurate; triallyl cyanurate, water and copper acetate, wherein the molar ratio is 1000-2000: 500:1 to 3; the temperature of the tubular reactor is controlled to be 130-150 ℃, and the retention time is 30-90 seconds; the temperature of the cooling crystallizer is controlled to be 10-30 ℃, the retention time is 10-20 minutes, and the molar ratio of triallyl cyanurate to o-xylene is 1:20 to 80.

And rectifying the reaction centrifugal filtrate to recover the triallyl cyanurate and the o-xylene, and using the recovered reaction centrifugal filtrate as a reaction raw material for subsequent reaction. The centrifuged crude diallyl isocyanurate product can be subjected to conventional operations such as acid washing, recrystallization and the like to obtain high-content diallyl isocyanurate and recycled catalyst and triallyl cyanurate, and the recycled catalyst and triallyl cyanurate can be used as reaction raw materials for subsequent reactions.

In the prior art, an intermittent kettle type reaction is adopted, so that the safety risk of material flushing caused by concentrated heat release is easy to occur, the materials are reacted in a high-temperature system with back mixing for a long time due to heat release, and byproducts are increased; the reaction has a large amount of solid, the traditional continuous reactor can not be suitable for the reaction under the condition that a large amount of solid is generated in the reaction process, experimental research shows that the problems can be well solved by adopting a tubular reactor with axial stirring as the continuous reactor, and continuous crystallization and aging can be realized by utilizing the tubular reactor with axial stirring, compared with the prior art, the invention has the advantages that:

1) The invention adopts the tubular reactor with axial stirring as the reactor to carry out continuous reaction, the temperature and the feeding speed are simple and controllable, the reaction time is short, and the formation of byproducts is effectively avoided;

2) The tubular reactor has large heat exchange area and less continuous reaction materials, so the unit heat dissipation area of the reaction is large, the sudden rapid heating process of the intermittent reaction does not exist, the reaction is stable, and the safety is high;

3) The method can realize continuous reaction, is simple to operate, is continuous and stable, and has high conversion rate and less side reaction;

4) Triallyl cyanurate has a melting point of 28 ℃, is liquid after being slightly heated, diallyl isocyanurate is a solid with poor solubility, triallyl cyanurate attached to the surface of the solid is easy to recycle by conventional means such as recrystallization and the like;

5) The reaction process and the post-treatment have continuity, the quality is stable, the product quality is stable among different batches, and the automatic production is convenient.

Detailed Description

The invention is further described below with reference to specific preferred examples, without thereby limiting the scope of protection of the invention.

Example 1:

the reaction device is installed, the materials are prepared, the material A is 200g of triallyl cyanurate and is dissolved in 1700g of o-xylene, the material B is 145.80mg of copper acetate and is dissolved in 7.23g of water, the material A and the material B are continuously added into the tubular reactor with axial stirring through two metering pumps respectively for reaction, and the flow rate of the two pumps ensures that the molar ratio of triallyl cyanurate entering the tubular reactor in unit time to water is 2:1, setting a tubular reactor at 150 ℃, and keeping the reaction liquid for 90 seconds; the liquid from the tubular reactor enters a tubular cooling crystallizer with axial stirring for cooling crystallization, the temperature of the tubular cooling crystallizer is set to be 30 ℃, and the retention time is 10 minutes; the crude product of diallyl isocyanurate obtained by centrifuging the material discharged from the tubular cooling crystallizer has the GC normalization content of 98.7%, the raw material content of 1.0% and the impurity content of 1 less than 0.1%.

Example 2:

the reaction device is well installed, the materials are prepared, the material A is 200g of triallyl cyanurate and is dissolved in 6800g of o-xylene, the material B is 218.38mg of copper acetate and is dissolved in 3.61g of water, the material A and the material B are continuously added into a tubular reactor with axial stirring through two metering pumps respectively for reaction, the flow rate of the two pumps ensures that the molar ratio of triallyl cyanurate entering the tubular reactor in unit time to water is 4:1, setting a tubular reactor at 130 ℃, and keeping the reaction liquid for 60 seconds; the liquid from the tubular reactor enters a tubular cooling crystallizer with axial stirring for cooling crystallization, the temperature of the tubular cooling crystallizer is set to be 10 ℃, and the retention time is 20 minutes; the material from the tubular cooling crystallizer is centrifuged to obtain crude diallyl isocyanurate, wherein the GC normalization content is 99.0%, the raw material is 0.7%, the content of the impurity 1 is less than 0.1%, the obtained crude diallyl isocyanurate is filtered by a hydrochloric acid chamber Wen Dajiang with the mass 2 times of that of the crude diallyl isocyanurate and the mass 3% of that of the crude diallyl isocyanurate, a filter cake is refluxed for 0.5h by o-xylene with the mass 2 times of that of the crude diallyl isocyanurate, the crude diallyl isocyanurate is cooled to room temperature and filtered, and the diallyl isocyanurate with the content of 99.9% is obtained after the filter cake is dried.

Example 3:

the reaction device is installed, the materials are prepared, the material A is 200g of triallyl cyanurate and is dissolved in 5100g of o-xylene, the material B is 194.39mg of copper acetate and is dissolved in 4.82g of water, the material A and the material B are respectively and continuously added into the tubular reactor with axial stirring through two metering pumps for reaction, the flow rate of the two pumps ensures that the molar ratio of triallyl cyanurate entering the tubular reactor in unit time to water is 3:1, setting a tubular reactor at 145 ℃, and keeping the reaction liquid for 30 seconds; the liquid from the tubular reactor enters a tubular cooling crystallizer with axial stirring for cooling crystallization, the temperature of the tubular cooling crystallizer is set to be 20 ℃, and the retention time is 15 minutes; the diallyl isocyanurate crude product obtained by centrifuging the material discharged from the tubular cooling crystallizer has the GC normalization content of 98.9%, the raw material content of 0.8% and the impurity content of 1 less than 0.1%.

Example 4:

the reaction device is well installed, the materials are prepared, the material A is 200g of triallyl cyanurate and is dissolved in 4260g of o-xylene, the material B is 162.13mg of copper acetate and is dissolved in 4.02g of water, the material A and the material B are respectively and continuously added into the tubular reactor with axial stirring through two metering pumps for reaction, the flow rate of the two pumps ensures that the molar ratio of triallyl cyanurate entering the tubular reactor in unit time to water is 18:5, setting the tubular reactor at 140 ℃, and keeping the reaction liquid for 40 seconds; the liquid from the tubular reactor enters a tubular cooling crystallizer with axial stirring for cooling crystallization, the temperature of the tubular cooling crystallizer is set to be 20 ℃, and the retention time is 20 minutes; the crude product of diallyl isocyanurate obtained by centrifuging the material discharged from the tubular cooling crystallizer has the GC normalization content of 98.7%, the raw material content of 1.0% and the impurity content of 1 less than 0.1%.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-described embodiments. All technical schemes belonging to the idea of the invention belong to the protection scope of the invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention, and such modifications and embellishments should also be considered as within the scope of the invention.

Claims

1. A method for continuously synthesizing diallyl isocyanurate, comprising the following steps:

pumping an o-xylene solution of triallyl cyanurate and a copper acetate aqueous solution into a tubular reactor with axial stirring for reaction by using two metering pumps according to a fixed proportion; then the material enters a tubular cooling crystallizer with axial stirring for cooling crystallization; centrifuging the crystallized material to obtain solid coarse diallyl isocyanurate product, and controlling the temperature in the tubular reactor at 130-150 deg.c for 30-90 sec; the temperature of the cooling crystallizer is controlled to be 10-30 ℃, and the retention time is 10-20 minutes.

2. The process for continuously synthesizing diallyl isocyanurate as claimed in claim 1, wherein triallyl cyanurate, water and copper acetate are mixed in a molar ratio of 1000 to 2000:500:1 to 3.

3. The process for the continuous synthesis of diallyl isocyanurate of claim 1 wherein the molar ratio of triallyl cyanurate to ortho-xylene is from 1:20 to 80.

4. The process for the continuous synthesis of diallyl isocyanurate as in claim 1, wherein triallyl cyanurate and ortho-xylene recovered from the reaction centrifugate by rectification can be used as raw materials for further reactions of subsequent batches.