阅读说明：本技术 一种受阻胺光稳定剂的制备方法及设备 (Preparation method and equipment of hindered amine light stabilizer ) 是由 曹凌峰 姜国平 蒋小平 于 2019-10-14 设计创作，主要内容包括：一种受阻胺光稳定剂的制备方法及设备,所述方法包括以下步骤：将哌啶醇、有机酸酯、催化剂加入反应容器中,在80～150℃下进行保温反应,然后在-0.05～-0.10MPa条件下蒸馏至无醇蒸出,再通过气体分布器通入惰性气体的气流,控制体系温度80～150℃下,控制体系压力继续保温反应直至反应结束,然后将反应液转出,经后处理得到产物；反应过程中升华的哌啶醇进入循环回收系统继续参与反应；所述设备包括：反应容器；物料收集罐,设置于反应容器顶部,用于收集升华物料；物料循环系统,用于将升华物料带回反应容器中；搅拌装置,设置于反应容器的顶部,并且搅拌装置的搅拌部从安装孔伸入反应容器内；惰性气体供给单元；副产物回收装置及真空系统等。本发明的有益效果是：反应过程不需要溶剂、绿色环保、反应进行彻底、原料利用率高,所得的醇含量较高可做副产品,生产工艺简单、操作方便。(A preparation method and equipment of a hindered amine light stabilizer are disclosed, wherein the method comprises the following steps: adding piperidinol, organic acid ester and a catalyst into a reaction container, carrying out heat preservation reaction at 80-150 ℃, distilling at-0.05-0.10 MPa until no alcohol is evaporated, introducing airflow of inert gas through a gas distributor, controlling the system temperature at 80-150 ℃, controlling the system pressure, continuing the heat preservation reaction until the reaction is finished, then transferring out the reaction liquid, and carrying out post-treatment to obtain a product; in the reaction process, sublimed piperidinol enters a circulating recovery system to continuously participate in the reaction; the apparatus comprises: a reaction vessel; the material collecting tank is arranged at the top of the reaction container and is used for collecting the sublimed materials; a material circulating system for bringing the sublimated material back to the reaction container; the stirring device is arranged at the top of the reaction container, and a stirring part of the stirring device extends into the reaction container from the mounting hole; an inert gas supply unit; a byproduct recovery device, a vacuum system, and the like. The invention has the beneficial effects that: the method has the advantages of no need of solvent in the reaction process, environmental protection, thorough reaction, high utilization rate of raw materials, high content of the obtained alcohol, simple production process and convenient operation, and can be used as a byproduct.)

1. A method for preparing a hindered amine light stabilizer, comprising the steps of:

1) mixing piperidinol, organic acid ester and a catalyst, carrying out heat preservation reaction at the temperature of 80-150 ℃, and evaporating part of generated alcohol, wherein the piperidinol is 2,2,6, 6-tetramethyl piperidinol or 1,2,2,6, 6-pentamethyl piperidinol; the organic acid ester is C8-C20 fatty acid, sebacic acid or ester formed by benzoic acid and low molecular weight alcohol; the low molecular weight alcohol is methanol, ethyl ester or isopropyl ester; the catalyst is titanate;

2) controlling the temperature in the reaction container to be 80-150 ℃ and the pressure to be-0.05 to-0.10 MPa, and then evaporating the generated alcohol;

3) introducing inert gas into the reaction container, controlling the temperature in the reaction container to be 80-150 ℃, the pressure to be-0.10 MPa and the pressure to be from negative pressure to 1Kg positive pressure, and continuously carrying out heat preservation reaction until the reaction is complete; and washing and drying the reacted materials to obtain the hindered amine light stabilizer. In the reaction process, the sublimed piperidinol is recovered and is reintroduced into the reaction vessel to participate in the reaction.

2. The method of preparing a hindered amine light stabilizer according to claim 1, wherein: no additional solvent is added in the reaction process to entrain the low molecular weight alcohol, but an inert gas is used in the step 3) to entrain the low molecular weight alcohol, so that the reaction equilibrium is pushed to move, and the reaction is promoted to be completely carried out.

3. A process for the preparation of a hindered amine light stabilizer according to claim 1 further characterized by: during the reaction, the sublimed piperidinol is collected and reintroduced into the reaction vessel to participate in the reaction.

4. The method of preparing a hindered amine light stabilizer according to claim 1, wherein: the mass ratio of the piperidinol to the organic acid ester group is 1-1.2: 1.

5. the method of preparing a hindered amine light stabilizer according to claim 1, wherein: the catalyst is tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate, isoamyl titanate and diethyl titanate, and the mass usage of the catalyst is 0.05-10% of the weight of the organic acid ester.

6. The method of preparing a hindered amine light stabilizer according to claim 1, wherein: the inert gas flow introduced in the step 3) is nitrogen.

7. The equipment constructed by the preparation method of the hindered amine light stabilizer according to any one of claims 1 to 6, which is characterized by comprising the following steps:

the reaction vessel is provided with a reaction cavity, the top of the reaction vessel is provided with a material circulation port and a mounting hole, and the bottom of the reaction vessel is provided with a liquid outlet for transferring materials out of the reaction vessel; the stirring device is arranged at the top of the reaction container, and a stirring part of the stirring device extends into the reaction container from the mounting hole and is used for stirring the materials filled into the reaction cavity;

the gas inlet end of the inert gas supply unit is communicated with an external inert gas source pipeline, and the gas outlet end of the inert gas supply unit is introduced into the bottom of the reaction container and is used for introducing inert gas into the reaction container;

and the feed inlet of the circulating recovery system is communicated with a pipeline at the bottom of the reaction container, and the discharge outlet of the circulating recovery system is communicated with the material distributor in the collection tank and is used for re-circulating and injecting the materials in the recovery tank into the reaction cavity of the reactor.

8. The apparatus of claim 7, wherein: the recycling system comprises a circulating pump, a collecting tank, a material communicating pipe, a material distributor and a material flow control valve, wherein the liquid inlet end of the circulating pump is communicated with a material pipe extending into the bottom of the reaction container, and the liquid outlet end of the circulating pump is introduced into the top of the collecting tank through a pipeline, is connected with the material distributor arranged on the top of the collecting tank and is used for injecting materials into the collecting tank; and the liquid outlet of the collecting tank is communicated with a material circulating port pipeline at the top of the reaction container and is used for re-injecting the materials in the collecting tank into the reaction container.

9. The apparatus of claim 8, wherein: the outer layer of the collecting tank is of a jacket type structure, wherein a jacket cooling and heating medium inlet and a jacket cooling and heating medium outlet are arranged on the jacket, and the jacket cooling and heating medium inlet and the jacket cooling and heating medium outlet are communicated with the inner cavity of the jacket and are used for filling a medium into the jacket to cool or heat the jacket; a plurality of tubes with fins are arranged in the collecting tank, and tube cooling and heating medium inlets and tube cooling and heating medium outlets of the fins extend to the outside of the collecting tank and are used for filling medium into the fins to cool or heat the fins; and the upper part and the lower part of the collecting tank are respectively provided with an observation port.

Technical Field

The invention relates to a preparation method and equipment of a hindered amine light stabilizer, belonging to the field of production and manufacturing of chemical products.

Background

In the prior art, one of the common methods for synthesizing the low molecular weight hindered amine light stabilizer is as follows: 2,2,6, 6-tetramethyl piperidinol or 1,2,2,6, 6-pentamethyl piperidinol and organic acid ester are subjected to ester exchange reaction in an organic solvent under the action of a catalyst, and the generated alcohol is taken out in a solvent distillation mode to push equilibrium movement so as to complete the reaction. The organic acid comprises fatty acid, sebacic acid, benzoic acid, butane tetracarboxylic acid and the like, and the ester is methyl ester or ethyl ester; the catalyst is titanate catalyst, sodium methoxide, dibutyltin oxide and the like. The titanate catalyst includes tetraisopropyl titanate, tetrabutyl titanate, isoamyl titanate, diethyl titanate, supported titanate catalyst, etc. The organic solvent is n-octane, xylene, petroleum ether and the like.

Chinese patent (CN103274994A) reacts polymerization inhibitor 701 (namely 2,2,6, 6-tetramethyl piperidinol nitroxide free radical) with methyl stearate in n-octane under the catalysis of titanate, methanol is taken out by distilling out n-octane, and the product is obtained by post-treatment. Chinese patent (CN101665457A) takes 2,2,6, 6-tetramethyl piperidinol and dimethyl sebacate as raw materials and dibutyl tin oxide as a catalyst to react in xylene. Chinese patent (CN101768104B) takes 1,2,2,6, 6-pentamethylpiperidinol and dimethyl sebacate as raw materials and takes activated carbon-supported titanate as a catalyst to react in petroleum ether. Chinese patent (CN101774963B) takes 2,2,6, 6-tetramethyl piperidinol and fatty acid methyl ester as raw materials, takes titanate ester and the like as catalysts, and reacts in alkane and naphthenic solvent such as n-octane and the like to prepare the corresponding light stabilizer. Chinese patent (CN101774963B) also uses n-octane alkane and cycloalkane as solvent, and adopts the mode of refluxing and separating methanol to drive reaction.

The defects of the prior art are as follows: 1. the used organic solvents are flammable and volatile solvents, potential safety hazards and unorganized gas emission are increased in the using process, environmental protection risks and treatment cost are increased, and meanwhile, the solvent loss also causes the production cost to be increased. 2. Because the methanol generated in the reaction process has certain solubility in the organic solvent, the methanol must be removed as much as possible before the solvent is used mechanically to ensure better use effect, which increases the post-treatment operation and cost. The methanol obtained by the reaction cannot be effectively utilized. 3. Because 2,2,6, 6-tetramethyl piperidinol or 1,2,2,6, 6-pentamethyl piperidinol sublimes, easy sublimation in the reaction, solvent distillation and recovery process leads to the distillation pipeline to block, influences the methanol to evaporate from the reaction system, and then influences the equilibrium movement of the ester exchange reaction, the reaction degree of progress is low. 4. The clogging of the piping also leads to a decrease in the distillation rate of the solvent and a large amount of solvent remains in the system. 5. Sublimation of 2,2,6, 6-tetramethylpiperidinol or 1,2,2,6, 6-pentamethylpiperidinol also causes a decrease in the utilization efficiency of raw materials, increasing the amount of raw materials used in charging.

Disclosure of Invention

Aiming at the problems of solvent loss, environmental pollution, potential safety hazard, solvent recycling after post-treatment and the like caused by using an organic solvent in the prior art; meanwhile, aiming at the problems that the raw material 2,2,6, 6-tetramethyl piperidinol or 1,2,2,6, 6-pentamethyl piperidinol is easy to sublimate to cause pipeline blockage, further distillation of alcohol and solvent distillation are influenced, the reaction progress degree is low, the solvent residual rate in a system is high, the raw materials such as the 2,2,6, 6-tetramethyl piperidinol or 1,2,2,6, 6-pentamethyl piperidinol cannot be fully utilized, and the like, the invention provides a preparation method and a device of the hindered amine light stabilizer. The method has the advantages of no need of solvent in the reaction process, environmental protection, thorough reaction, high utilization rate of raw materials, high content of the obtained alcohol, simple production process and convenient operation, and can be used as a byproduct.

The preparation method of the hindered amine light stabilizer is characterized by comprising the following steps of:

1) mixing piperidinol, organic acid ester and a catalyst, performing heat preservation reaction at the temperature of 80-150 ℃, and evaporating part of generated alcohol; wherein the piperidinol is 2,2,6, 6-tetramethylpiperidinol or 1,2,2,6, 6-pentamethylpiperidinol; the organic acid ester is C8-C20 fatty acid, sebacic acid or ester formed by benzoic acid and low molecular weight alcohol; the low molecular weight alcohol is methanol, ethyl ester or isopropyl ester. The catalyst is titanate

2) Controlling the temperature in the reaction container to be 80-150 ℃ and the pressure to be-0.05 to-0.10 MPa, and further evaporating the generated alcohol;

3) and introducing inert gas into the reaction container, controlling the temperature in the reaction container to be 80-150 ℃ and the pressure to be-0.10 MPa, and continuing to perform heat preservation reaction until the reaction is complete. And washing and drying the reacted materials to obtain the hindered amine light stabilizer. In the reaction process, the sublimed piperidinol is recovered and is reintroduced into the reaction vessel to participate in the reaction.

No additional solvent is added in the reaction process to entrain the low molecular weight alcohol, but an inert gas is used in the step 3) to entrain the low molecular weight alcohol, so that the reaction equilibrium is pushed to move, and the reaction is promoted to be completely carried out.

During the reaction, the sublimed piperidinol is collected and reintroduced into the reaction vessel to participate in the reaction.

The mass ratio of the piperidinol to the organic acid ester group is 1-1.2: 1.

the catalyst is tetramethyl titanate, tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate, isoamyl titanate and diethyl titanate, and the mass usage of the catalyst is 0.05-10% of the weight of the organic acid ester.

The temperature of the steps 1) to 3) is preferably 100-140 ℃.

The equipment constructed by the preparation method of the hindered amine light stabilizer is characterized by comprising the following steps:

the reaction vessel is provided with a reaction cavity, the top of the reaction vessel is provided with a material circulation port and a mounting hole, and the bottom of the reaction vessel is provided with a liquid outlet for transferring materials out of the reaction vessel; the gas inlet end of the inert gas supply unit is communicated with an external inert gas source pipeline, and the gas outlet end of the inert gas supply unit is introduced into the bottom of the reaction container and is used for introducing inert gas into the reaction container;

and the feed inlet of the circulating recovery system is communicated with a pipeline at the bottom of the reaction container, and the discharge outlet of the circulating recovery system is communicated with the material distributor in the collection tank and is used for re-circulating and injecting the materials in the recovery tank into the reaction cavity of the reactor.

The circulating recovery system comprises a circulating pump, a collecting tank, a material communicating pipe, a material distributor and a material flow control valve, wherein the liquid inlet end of the circulating pump is communicated with a material pipe extending into the bottom of the reaction container, and the liquid outlet end of the circulating pump is introduced into the top of the collecting tank through a pipeline, is connected with the material distributor arranged on the top of the collecting tank and is used for injecting materials into the collecting tank; and the liquid outlet of the collecting tank is communicated with a material circulating port pipeline at the top of the reaction container and is used for re-injecting the materials in the collecting tank into the reaction container.

The outer layer of the collecting tank is of a jacket type structure, wherein a jacket cooling and heating medium inlet and a jacket cooling and heating medium outlet are arranged on the jacket, and the jacket cooling and heating medium inlet and the jacket cooling and heating medium outlet are communicated with the inner cavity of the jacket and are used for filling cooling or heating media into the jacket to cool or heat the jacket; a plurality of tube arrays with fins are arranged in the collecting tank, and tube array cooling and heating medium inlets and tube array cooling and heating medium outlets of the fins extend to the outside of the collecting tank and are used for filling cooling or heating media into the fins so as to cool or heat the fins; and the upper part and the lower part of the collecting tank are respectively provided with an observation port.

The circulating material inlet of the collecting tank is positioned at the upper part of the collecting tank, and the circulating material inlet is provided with a material distributor, wherein the feed inlet of the material distributor is communicated with the discharge outlet pipeline of the material communicating pipe.

And the material communicating pipe is provided with a control valve for controlling the flow rate of the material.

The stirring device comprises a stirring motor and a stirring paddle, the stirring motor is arranged at the top of the reaction container, the stirring paddle frame is arranged at the mounting hole of the reaction container, the output shaft of the stirring motor is connected with the upper end of the stirring paddle, and the lower end of the stirring paddle extends into the reaction cavity of the reaction container from the mounting hole and is used for stirring materials filled into the reaction cavity.

The inert gas supply unit comprises an inert gas inlet pipe, a gas flowmeter, a gas flow control valve and a gas distributor, wherein the gas inlet end of the inert gas inlet pipe is communicated with an external inert gas source, and the gas outlet end of the inert gas inlet pipe extends into the bottom of the reaction chamber from the top of the reaction container along the inner wall and is connected with the gas distributor arranged at the bottom of the reaction chamber and used for distributing inert gas into the reaction chamber; the gas flow meter and the gas flow control valve are both arranged on the inert gas inlet pipe and used for controlling the flow of the inert gas.

Still include accessory substance collecting system, accessory substance collecting system includes condenser and accessory substance collecting tank, the air inlet of condenser and the gas outlet pipeline intercommunication at collecting tank top, the liquid outlet of condenser and the inlet pipeline intercommunication of accessory substance collecting tank for discharge into the accessory substance collecting tank after with the accessory substance condensation of collecting tank top effusion.

The top of the byproduct collecting tank is provided with a vent hole which can be communicated with the inner cavity, and the vent hole is communicated with an external vacuum system pipeline through a vacuum tube and used for adjusting the pressure in the byproduct collecting tank.

And control valves are respectively arranged on pipelines connected with the liquid inlet and the liquid outlet of the byproduct collecting tank.

The invention has the beneficial effects that: the method has the advantages of no need of solvent in the reaction process, environmental protection, thorough reaction, high utilization rate of raw materials, high content of the obtained alcohol, simple production process and convenient operation, and can be used as a byproduct.

Drawings

FIG. 1 is a block diagram of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

With reference to the accompanying drawings:

example 1A reaction vessel was charged with 345.8Kg (2.2kmol) of 2,2,6, 6-tetramethylpiperidinol, 230.3Kg (1kmol) of dimethyl sebacate, and 2.84Kg (0.01mol) of tetraisopropyl titanate as a catalyst, and the temperature was raised to 120 to 125 ℃ to conduct a heat-retaining reaction while controlling the system pressure at-0.05 to-0.100 MPa and distilling the alcohol generated in the reaction until it was almost not distilled out. And opening the vacuum to ensure that the system is vacuumized to-0.098 MPa. And introducing airflow of nitrogen through a gas distributor, and controlling the temperature of the system to be 120-125 ℃ to continue the heat preservation reaction. Sublimed 2,2,6, 6-tetramethylpiperidinol during the reaction was collected in a collection tank. When a certain amount of 2,2,6, 6-tetramethyl piperidinol is collected in the recovery tank, the material circulating system is intermittently started, and the sublimed raw materials are brought back to the reaction system by the materials in the reaction system to continuously participate in the reaction. The end point of the reaction is monitored by gas chromatography. And continuously introducing the nitrogen gas flow, controlling the system temperature to be 130-135 ℃, controlling the vacuum degree of the system to be more than-0.098 MPa, introducing the nitrogen gas flow through a gas distributor, and collecting the excessive tetramethyl piperidinol in a collection tank for the next batch. And then transferring the reaction solution into a washing and drying kettle, and carrying out washing and drying post-treatment to obtain a product. The yield of bis (2,2,6, 6-tetramethylpiperidinol) sebacate was 97.5%, the content was 98.8%.

Example 2 the feeding formula in example 1 is changed to 330.1Kg (2.1kmol) of 2,2,6, 6-tetramethylpiperidinol, 230Kg (1kmol) of dimethyl sebacate and 5.68Kg (0.02mol) of tetramethyltitanate as a catalyst, the temperature is increased to 120-125 ℃ for reaction, and the 2,2,6, 6-tetramethylpiperidinol in the collection tank is dissolved by methanol generated by the reaction and enters a reaction kettle. The subsequent operation was carried out with reference to example 1. The yield of the bis (2,2,6, 6-tetramethylpiperidinol) sebacate was 97.6%, and the content was 98.6%.

Examples 3 to 5

The yield and quality conditions of the bis (2,2,6, 6-tetramethylpiperidinol) sebacate and the bis (1, 2,2,6, 6-pentamethylpiperidinol) sebacate are prepared by adjusting the formula, the reaction temperature, the vacuum degree and other operation conditions. Specific formulations and operating parameters are shown in table 1.

TABLE 1 preparation of bis (2,2,6, 6-tetramethylpiperidinol) sebacate and bis (1, 2,2,6, 6-pentamethylpiperidinol) sebacate

The method and the device can also be used for preparing 2,2,6, 6-tetramethyl piperidyl fatty acid ester and 1,2,2,6, 6-pentamethyl piperidyl alcohol-based fatty acid ester. The operation parameters, yield and quality results of the process formula of the specific examples 6-8 are shown in table 2:

TABLE 2 preparation of Tetramethylpiperidinyl and pentamethylpiperidinyl alcohol fatty acid esters

The method and the device can also be used for preparing 2,2,6, 6-tetramethyl piperidyl benzoate and 1,2,2,6, 6-pentamethyl piperidyl benzoate. The operation parameters, yield and quality results of the process formula of the specific examples 9-10 are shown in table 3:

TABLE 3 preparation of Tetramethylpiperidinyl benzoate and pentamethylpiperidinol benzoate

Example 11 an apparatus constructed in accordance with the method of making a hindered amine light stabilizer of example 1 includes:

the reaction vessel 1 is provided with a reaction cavity, the top of the reaction vessel is provided with a material circulation port and a mounting hole, the bottom of the reaction vessel is provided with a liquid outlet, a liquid outlet pipeline arranged at the liquid outlet is divided into two paths, and the first path 11 is a post-treatment pipeline after the reaction is finished and is used for discharging final reaction liquid; the second path 12 is used as a material circulating pipeline and is communicated with a feed inlet pipeline of the circulating recovery system, and is used for reintroducing the materials collected by the circulating recovery system into the reaction vessel to participate in reaction;

the stirring device 2 is arranged at the top of the reaction container, and a stirring part of the stirring device extends into the reaction container from the mounting hole and is used for stirring materials filled in the reaction cavity;

the gas inlet end of the inert gas supply unit 3 is communicated with an external inert gas source pipeline, and the gas outlet end of the inert gas supply unit is introduced into the bottom of the reaction container and is used for introducing inert gas into the reaction container;

and a recycling system 4, the inlet of which is communicated with a pipeline extending into the bottom of the reaction vessel, and the outlet of which is communicated with a material distributor 44 on a collecting tank 42, and is used for recycling the recycled materials into the reaction cavity of the reactor.

The circulating recovery system 4 comprises a circulating pump 41, a collecting tank 42, a material communicating pipe 43, a material distributor 44 and a material flow control valve 45, wherein the liquid inlet end of the circulating pump 41 is communicated with the material communicating pipe 43 extending into the bottom of the reaction vessel, and the liquid outlet end of the circulating pump 41 is introduced into the top of the collecting tank 42 through a pipeline and is connected with the material distributor 44 arranged at the top of the collecting tank 42 for injecting materials into the collecting tank 42; the liquid outlet of the collecting tank 42 is communicated with a material circulating port pipeline at the top of the reaction vessel 1, and is used for re-injecting the materials in the collecting tank into the reaction vessel.

The outer layer of the collecting tank 42 is of a jacket type structure, wherein a jacket cooling and heating medium inlet 421 and a jacket cooling and heating medium outlet 422 are arranged on the jacket, and the jacket cooling and heating medium inlet 421 and the jacket cooling and heating medium outlet 422 are both communicated with the inner cavity of the jacket and are used for filling a medium into the jacket to cool or heat the jacket; a plurality of finned tubes 423 are arranged in the collecting tank 42, and cooling and heating medium inlets 424 and cooling and heating medium outlets 425 of the finned tubes 423 extend to the outside of the collecting tank 42 and are used for pouring media into the fins to cool or heat the fins; the upper and lower parts of the collecting tank 42 are respectively provided with a viewing port 426.

The circulating material inlet of the collecting tank 42 is positioned at the upper part of the collecting tank, and the circulating material inlet is provided with a material distributor 44, wherein the inlet of the material distributor 44 is communicated with the outlet pipeline of the material communicating pipe 43.

And the material communicating pipe 43 is provided with a control valve 45 for controlling the flow rate of the material.

Agitating unit 2 includes agitator motor 21 and stirring rake 22, and agitator motor 21 sets up in reaction vessel 1's top, and stirring rake 22 erects in reaction vessel 1's mounting hole department to agitator motor 21's output shaft links to each other with stirring rake 22's upper end, and stirring rake 22's lower extreme stretches into the reaction intracavity of reaction vessel 1 from the mounting hole for the material of stirring packing into the reaction intracavity.

The inert gas supply unit 3 comprises an inert gas inlet pipe 31, a gas flowmeter 32, a gas amount control valve 33 and a gas distributor 34, wherein the gas inlet end of the inert gas inlet pipe 31 is communicated with an external inert gas source, and the gas outlet end of the inert gas inlet pipe 31 extends into the bottom of the reaction chamber from the top of the reaction container 1 along the inner wall and is connected with the gas distributor 34 arranged at the bottom of the reaction chamber and used for distributing inert gas into the reaction chamber; the gas flow meter 32 and the gas amount control valve 33 are both arranged on the inert gas inlet pipe 31 and used for controlling the flow rate of the inert gas. The top of the byproduct collecting tank is provided with a vent hole which can be communicated with the inner cavity, and the vent hole is communicated with an external vacuum system pipeline through a vacuum tube and used for adjusting the pressure in the byproduct collecting tank.

And control valves are respectively arranged on pipelines connected with the liquid inlet and the liquid outlet of the byproduct collecting tank.

The equipment constructed by the preparation method of the hindered amine light stabilizer also comprises various deformations, such as a material communicating pipe 43 extending into the bottom of the reaction cavity from the outside of the reaction container at the top of the reaction container 1; the nitrogen inlet pipe 31 may be connected to the gas distributor 34 from outside the reaction vessel through the bottom into the interior of the reaction vessel at a bottom position.

The embodiments described in the present specification and shown in the drawings are merely illustrative of the implementation forms of the inventive concept, and the scope of the present invention should not be construed as being limited to the specific forms set forth in the embodiments, but also includes equivalent technical means which can be conceived by those skilled in the art based on the inventive concept.