Production method for improving photo-thermal stability of chloromethyl ether industrial product

Abstract

The invention relates to a production method for improving photo-thermal stability of a chloromethyl ethyl ether industrial product, and belongs to the technical field of chloromethyl ethyl ether processing.The preparation of an intermediate 1 comprises the steps that 80-120 mL of ethyl alcohol, 20-25 g of 3, 5-di-tert-butyl-4-hydroxybenzaldehyde and 6-10 g of n-butylamine are added into a 250 mL four-opening bottle provided with a backflow water diversion device, the temperature is increased to 60 DEG C, a reaction is carried out for 1 h, and an intermediate 2 is obtained; cooling to 0 DEG C by adopting an ice salt bath, adding 1-3g of potassium borohydride in batches, keeping the temperature at 0 DEG C, continuing to react for 0.5 hour, and adding a 5% citric acid aqueous solution to adjust the pH value to 2.0-3.0; the special photo-thermal stabilizer is synthesized and compounded with the epoxidized soybean oil, a single stabilizer and a special formula free of chloromethyl ether are generally adopted in the traditional method, the photo-thermal stabilizer containing the hindered phenol and piperazine structure is synthesized by the method, synergistic protection of light shielding, thermal stability and acid capture is achieved after compounding, and the product performance is remarkably improved; and the purity retention rate is 95-97% after 168h of ultraviolet aging.

Description

Technical Field

[0001] This invention belongs to the field of chloromethyl ethyl ether processing technology, specifically relating to a production method for improving the photothermal stability of industrial chloromethyl ethyl ether products. Background Technology

[0002] Chloromethyl ethyl ether decomposes readily when exposed to light and heat, producing toxic hydrogen chloride and formaldehyde gases. Therefore, photo- and heat stabilizers are often added during the production and processing of chloromethyl ethyl ether to effectively prevent its decomposition.

[0003] However, traditional chloromethyl ethyl ether stabilizers are mostly general-purpose single-component stabilizers with poor specificity, making it difficult to simultaneously achieve both light and heat stability. Traditional stabilizers are prone to problems such as low thermal decomposition temperature and easy degradation and failure under ultraviolet light. They cannot effectively inhibit side reactions such as dechlorination and decomposition of chloromethyl ethyl ether, resulting in rapid decline in product purity and poor storage stability. Summary of the Invention

[0004] The purpose of this invention is to provide a production method for improving the photothermal stability of industrial chloromethyl ethyl ether products in order to solve the above-mentioned problems.

[0005] The present invention achieves the above objectives through the following technical solutions: This invention provides a production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether, comprising the following steps: Step S1, Preparation of Intermediate 1: Add 80-120 mL of ethanol, 20-25 g of 3,5-di-tert-butyl-4-hydroxybenzaldehyde and 6-10 g of n-butylamine to a 250 mL four-necked flask equipped with a reflux water separator. Heat to 60 °C and react for 1 h. Cool to 0 °C using an ice-salt bath. Add 1-3 g of potassium borohydride in batches and continue the reaction at 0 °C for 0.5 h. Add 5% citric acid aqueous solution to adjust the pH to 2.0-3.0. After removing ethanol by rotary evaporation, adjust the pH to 8.0-9.0 using 10% sodium hydroxide aqueous solution. Extract with dimethyl carbonate, 120-150 mL each time, for 3 extractions. Obtain the yellow oily intermediate 1 by rotary evaporation. Step S2, Preparation of Intermediate 2: Add 80-100 mL of diethyl ether to a 250 mL four-necked flask, cool to below 5 °C in an ice bath, add 8-10 g of trichloroisocyanuric acid, stir well, and slowly add 30-45 mL of diethyl ether solution containing 10-15 g of intermediate 1. After the addition is complete, react for 2 h, then add 5-10 mL of 20% sodium hydroxide aqueous solution. After the addition is complete, continue to react for 3 h. Transfer the reaction solution to a separatory funnel, wash with water, and after drying, filtration, and concentration, obtain intermediate 2 as a light yellow solid. Step S3, Preparation of light stabilizer precursor: Intermediate 2 and hexamethylenediamine piperidine were added to a 500mL autoclave at a mass ratio of 1:2.2. 200-300mL of trimethylbenzene was added, the autoclave was sealed, and the air inside was replaced with nitrogen three times. The temperature was raised to 80℃ and reacted for 2h. After cooling, the autoclave was opened, nitrogen was purged to 0.6MPa, and the autoclave was heated and stirred and heated to 170℃ for 6h. After cooling, releasing the gas, and opening the autoclave, the reaction solution was filtered. The organic phase was washed with a 10% sodium chloride aqueous solution, and the solvent was evaporated under reduced pressure to obtain a white solid as the light stabilizer precursor. Step S4, Preparation of light stabilizer: Add 100 mL of anhydrous dimethyl carbonate to a 250 mL four-necked flask, add all the above light stabilizer precursors, stir until completely dissolved, slowly add 8-10 mL of acetic anhydride dropwise at room temperature, after the addition is complete, raise the temperature to 40℃ and react at a constant temperature for 1.5 h, slowly add distilled water dropwise to the reaction solution, wash twice, 50 mL each time, to remove excess acetic anhydride and the generated acetic acid, dry the organic phase with anhydrous magnesium sulfate, filter, remove dimethyl carbonate by rotary evaporation under reduced pressure, and obtain a white powdery solid, which is then pulverized to obtain the light stabilizer.

[0006] Step S5: In an industrial reactor protected from light, water, and nitrogen, add crude industrial chloromethyl ethyl ether. First, add the light stabilizer at 0.02%-0.12% of the crude chloromethyl ethyl ether mass, controlling the stirring speed at 150-200 r / min and stirring for 20-30 min until completely dissolved. Then, add an epoxy acid scavenger at 0.05%-0.2% of the crude chloromethyl ethyl ether mass and continue stirring for 15-20 min until uniformly mixed. Seal the reactor and replace the air inside with nitrogen 2-3 times, each time purging with nitrogen to 0.2-0.3 MPa, maintaining this pressure for 5-10 min before venting. After replacement, maintain the pressure inside the reactor at 0.02-0.05 MPa and let it stand at room temperature in the dark for 1-2 h to obtain chloromethyl ethyl ether with good photothermal stability.

[0007] As a further optimization of the present invention, in step S1, potassium borohydride is added in 3-5 batches, with an interval of 5-10 minutes between each batch, and the system temperature is kept at 0°C during the addition process.

[0008] As a further optimization of the present invention, in step S1, rotary evaporation to remove ethanol is carried out under reduced pressure, with the rotary evaporation temperature controlled at 35-40°C and the vacuum degree at 0.08-0.1 MPa.

[0009] As a further optimization of the present invention, the dropping rate of the ether solution of intermediate 1 is 1-2 mL / min, and the system temperature is maintained at 0-5℃ during the dropping process.

[0010] As a further optimization of the present invention, in step S2, the water washing process is as follows: the reaction solution is washed with deionized water 2-3 times, and the amount of water used for each wash is 50-80 mL.

[0011] As a further optimization of the present invention, in step S3, the specific operation of replacing air with nitrogen is as follows: nitrogen is introduced into the autoclave to 0.2-0.3 MPa, maintained for 5-10 minutes and then vented, and this is repeated 3 times.

[0012] As a further optimization of the present invention, in step S3, when the solvent is evaporated under reduced pressure, the vacuum degree is 0.09-0.1 MPa and the evaporation temperature is 80-100℃.

[0013] As a further optimization of the present invention, in step S5, the epoxy acid scavenger is epoxidized soybean oil.

[0014] As a further optimization of the present invention, in step S3, the organic phase is washed twice with a sodium chloride aqueous solution with a mass fraction of 10%, and the amount of water used for each wash is 100-150 mL.

[0015] As a further optimization of the present invention, in step S4, the rotary evaporation temperature is controlled at 55-65℃, and the vacuum degree is 0.08-0.1MPa. The beneficial effects of this invention are as follows: This invention synthesizes a special photothermal stabilizer and combines it with epoxidized soybean oil. Traditional methods often use a single stabilizer and lack a special formulation for chloromethyl ethyl ether. This method synthesizes a photothermal stabilizer containing hindered phenol and piperazine structures. After compounding, it achieves synergistic protection of light shielding and thermal stability, significantly improving product performance: the DSC initial decomposition temperature is 68-73℃, and the purity retention rate after 168 hours of UV aging is 95%-97%, both of which are superior to traditional methods. Moreover, it uses a green solvent, reducing toxicity and cost, and improving the safety and durability of industrial storage. Detailed Implementation

[0016] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0017] Unless otherwise specified, all methods used in this invention are conventional methods known to those skilled in the art, and all reagents and materials used are commercially available products.

[0018] Example 1 Preparation of Intermediate 1: 80 mL of ethanol, 20 g of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and 6 g of n-butylamine were added to a 250 mL four-necked flask equipped with a reflux dehydration device. The mixture was heated to 60 °C and reacted for 1 h. The temperature was then lowered to 0 °C using an ice-salt bath. 1 g of potassium borohydride was added in three batches, with a 5 min interval between each batch. The system temperature was maintained at 0 °C during the addition process. The reaction was continued at 0 °C for 0.5 h. The pH was adjusted to 2.0 by adding 5% citric acid aqueous solution. After removing the ethanol by rotary evaporation, the pH was adjusted to 8.0 by adding 10% sodium hydroxide aqueous solution. The mixture was extracted with dimethyl carbonate, 120 mL each time, for three extractions. The resulting yellow oily intermediate 1 was obtained by rotary evaporation (removing the ethanol by rotary evaporation under reduced pressure, with the rotary evaporation temperature controlled at 35 °C and the vacuum degree at 0.08 MPa). Preparation of intermediate 2: Add 80 mL of diethyl ether to a 250 mL four-necked flask, cool to below 5 °C in an ice bath, add 8 g of trichloroisocyanuric acid, stir well, and then slowly add 30 mL of diethyl ether solution containing 10 g of intermediate 1. The dropping rate of the diethyl ether solution of intermediate 1 is 1 mL / min. During the dropping process, keep the system temperature at 0 °C. After the dropping is completed, react for 2 h, then add 5 mL of 20% sodium hydroxide aqueous solution. After the dropping is completed, continue to react for 3 h. Transfer the reaction solution to a separatory funnel and wash with water (the water washing process is: wash the reaction solution twice with deionized water, each time using 50 mL of water). After drying, filtering, and concentration, obtain intermediate 2 as a light yellow solid. Preparation of the light stabilizer precursor: Intermediate 2 and hexamethylenediamine piperidine were added to a 500 mL autoclave at a mass ratio of 1:2.2. 200 mL of trimethylbenzene was added, and the autoclave was sealed. The air inside the autoclave was replaced with nitrogen three times (the specific operation of nitrogen replacement is: purge the autoclave with nitrogen to 0.2 MPa, maintain for 5 min, and then release the air, repeat 3 times). The temperature was raised to 80 °C and reacted for 2 h. After cooling, the autoclave was opened, and nitrogen was purged to 0.6 MPa. The autoclave was heated and stirred and then heated to 170 °C and reacted for 6 h. After cooling, releasing the gas, and opening the autoclave, the reaction solution was filtered. The organic phase was washed twice with a 10% sodium chloride aqueous solution, with 100 mL of water used for each wash. The solvent was distilled off under reduced pressure (the vacuum degree was 0.09 MPa and the distillation temperature was 80 °C) to obtain a white solid as the light stabilizer precursor. Preparation of light stabilizer: Add 100 mL of anhydrous dimethyl carbonate to a 250 mL four-necked flask, add all the above light stabilizer precursors, stir until completely dissolved, slowly add 8 mL of acetic anhydride dropwise at room temperature, after the addition is complete, raise the temperature to 40 °C and react at a constant temperature for 1.5 h, slowly add distilled water dropwise to the reaction solution, wash twice, 50 mL each time, to remove excess acetic anhydride and the generated acetic acid, dry the organic phase with anhydrous magnesium sulfate, filter, remove dimethyl carbonate by rotary evaporation under reduced pressure, and obtain a white powdery solid, which is then pulverized to obtain the light stabilizer.

[0019] In an industrial reactor protected from light, water, and nitrogen, crude industrial chloromethyl ethyl ether was added. First, the light stabilizer was added at 0.02% of the crude chloromethyl ethyl ether mass, and the stirring speed was controlled at 150 r / min for 20 min until completely dissolved. Then, epoxidized soybean oil was added at 0.05% of the crude chloromethyl ethyl ether mass, and stirring was continued for 15 min until uniformly mixed. The reactor was sealed, and the air inside was replaced with nitrogen twice, each time purging nitrogen to 0.2 MPa and maintaining this pressure for 5 min before venting. After the replacement was completed, the pressure inside the reactor was maintained at 0.02 MPa, and the reactor was allowed to stand at room temperature in the dark for 1 h to obtain chloromethyl ethyl ether with good photothermal stability.

[0020] Example 2 Preparation of Intermediate 1: 100 mL of ethanol, 22 g of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and 8 g of n-butylamine were added to a 250 mL four-necked flask equipped with a reflux dehydration device. The mixture was heated to 60 °C and reacted for 1 h. The temperature was then lowered to 0 °C using an ice-salt bath. 2 g of potassium borohydride was added in four batches, with an 8-min interval between each batch. The system temperature was maintained at 0 °C during the addition process. The reaction was continued at 0 °C for 0.5 h. The pH was adjusted to 2.0 by adding 5% citric acid aqueous solution. After removing the ethanol by rotary evaporation, the pH was adjusted to 9.0 by adding 10% sodium hydroxide aqueous solution. The mixture was extracted with dimethyl carbonate, 135 mL each time, for three extractions. The resulting yellow oily intermediate 1 was obtained by rotary evaporation (removing the ethanol by rotary evaporation under reduced pressure, with the evaporation temperature controlled at 37 °C and the vacuum degree at 0.09 MPa). Preparation of Intermediate 2: Add 90 mL of diethyl ether to a 250 mL four-necked flask, cool to below 5 °C in an ice bath, add 9 g of trichloroisocyanuric acid, stir well, and then slowly add 35 mL of diethyl ether solution containing 12 g of Intermediate 1. The dropping rate of the diethyl ether solution of Intermediate 1 is 2 mL / min. During the dropping process, keep the system temperature at 3 °C. After the dropping is completed, react for 2 h. Then add 8 mL of 20% sodium hydroxide aqueous solution. After the dropping is completed, continue to react for 3 h. Transfer the reaction solution to a separatory funnel and wash with water (the water washing process is: wash the reaction solution with deionized water 3 times, and the water volume for each wash is 65 mL). After drying, filtering and concentrating, obtain intermediate 2, a light yellow solid. Preparation of the light stabilizer precursor: Intermediate 2 and hexamethylenediamine piperidine were added to a 500 mL autoclave at a mass ratio of 1:2.2. 250 mL of trimethylbenzene was added, and the autoclave was sealed. The air inside the autoclave was replaced with nitrogen three times (the specific operation of nitrogen replacement is as follows: nitrogen is charged into the autoclave to 0.25 MPa, maintained for 8 min, and then vented. This is repeated 3 times). The temperature was raised to 80 °C and reacted for 2 h. After cooling, the autoclave was opened, nitrogen was charged to 0.6 MPa, and the autoclave was heated and stirred and then heated to 170 °C and reacted for 6 h. After cooling, venting, and opening the autoclave, the reaction solution was filtered. The organic phase was washed twice with a 10% sodium chloride aqueous solution, with 125 mL of water used for each wash. The solvent was distilled off under reduced pressure (the vacuum degree was 0.09 MPa and the distillation temperature was 90 °C) to obtain a white solid as the light stabilizer precursor. Preparation of light stabilizer: Add 100 mL of anhydrous dimethyl carbonate to a 250 mL four-necked flask, add all the above light stabilizer precursors, stir until completely dissolved, slowly add 9 mL of acetic anhydride dropwise at room temperature, after the addition is complete, raise the temperature to 40 °C and react at a constant temperature for 1.5 h, slowly add distilled water dropwise to the reaction solution, wash twice, 50 mL each time, to remove excess acetic anhydride and the generated acetic acid, dry the organic phase with anhydrous magnesium sulfate, filter, remove dimethyl carbonate by rotary evaporation under reduced pressure, and obtain a white powder solid, which is then pulverized to obtain the light stabilizer.

[0021] In an industrial reactor protected from light, water, and nitrogen, crude industrial chloromethyl ethyl ether was added. First, the light stabilizer was added at 0.06% of the crude chloromethyl ethyl ether mass, and the stirring speed was controlled at 180 r / min for 25 min until completely dissolved. Then, epoxidized soybean oil was added at 0.1% of the crude chloromethyl ethyl ether mass, and stirring was continued for 17 min until uniformly mixed. The reactor was sealed, and the air inside was replaced with nitrogen three times, each time purging nitrogen to 0.2 MPa and maintaining this pressure for 8 min before venting. After the replacement was completed, the pressure inside the reactor was maintained at 0.03 MPa, and the reactor was allowed to stand at room temperature in the dark for 1.5 h to obtain chloromethyl ethyl ether with good photothermal stability.

[0022] Example 3 Preparation of Intermediate 1: 120 mL of ethanol, 25 g of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and 10 g of n-butylamine were added to a 250 mL four-necked flask equipped with a reflux dehydration device. The mixture was heated to 60 °C and reacted for 1 h. The temperature was then lowered to 0 °C using an ice-salt bath. 3 g of potassium borohydride was added in 5 batches, with each batch added 10 min apart. The system temperature was maintained at 0 °C during the addition process. The reaction was continued at 0 °C for 0.5 h. The pH was adjusted to 3.0 by adding 5% citric acid aqueous solution. After removing the ethanol by rotary evaporation, the pH was adjusted to 9.0 by adding 10% sodium hydroxide aqueous solution. The mixture was extracted with dimethyl carbonate, 150 mL each time, for 3 extractions. The mixture was then rotary evaporated to obtain a yellow oily intermediate 1. (The rotary evaporation to remove the ethanol was carried out under reduced pressure, with the rotary evaporation temperature controlled at 40 °C and the vacuum degree at 0.1 MPa). Preparation of intermediate 2: Add 100 mL of diethyl ether to a 250 mL four-necked flask, cool to below 5 °C in an ice bath, add 10 g of trichloroisocyanuric acid, stir well, and then slowly add 45 mL of diethyl ether solution containing 15 g of intermediate 1. The dropping rate of the diethyl ether solution of intermediate 1 is 2 mL / min. During the dropping process, keep the system temperature at 5 °C. After the dropping is completed, react for 2 h. Then add 10 mL of 20% sodium hydroxide aqueous solution. After the dropping is completed, continue to react for 3 h. Transfer the reaction solution to a separatory funnel and wash with water (the water washing process is: wash the reaction solution with deionized water 3 times, and the water volume for each wash is 80 mL). After drying, filtering and concentrating, intermediate 2, a light yellow solid, is obtained. Preparation of the light stabilizer precursor: Intermediate 2 and hexamethylenediamine piperidine were added to a 500 mL autoclave at a mass ratio of 1:2.2. 300 mL of trimethylbenzene was added, and the autoclave was sealed. The air inside the autoclave was replaced with nitrogen three times (the specific operation of nitrogen replacement is: purge the autoclave with nitrogen to 0.3 MPa, maintain for 10 min and then release the air, repeat 3 times). The temperature was raised to 80 °C and reacted for 2 h. After cooling, the autoclave was opened, and nitrogen was purged to 0.6 MPa. The autoclave was heated and stirred and the temperature was raised to 170 °C and reacted for 6 h. After cooling, releasing the gas, and opening the autoclave, the reaction solution was filtered. The organic phase was washed twice with a 10% sodium chloride aqueous solution, with 150 mL of water used for each wash. The solvent was distilled off under reduced pressure (the vacuum degree was 0.1 MPa and the distillation temperature was 100 °C) to obtain a white solid as the light stabilizer precursor. Preparation of light stabilizer: Add 100 mL of anhydrous dimethyl carbonate to a 250 mL four-necked flask, add all the above light stabilizer precursors, stir until completely dissolved, slowly add 10 mL of acetic anhydride dropwise at room temperature, after the addition is complete, raise the temperature to 40 °C and react at a constant temperature for 1.5 h, slowly add distilled water dropwise to the reaction solution, wash twice, 50 mL each time, to remove excess acetic anhydride and the generated acetic acid, dry the organic phase with anhydrous magnesium sulfate, filter, remove dimethyl carbonate by rotary evaporation under reduced pressure, and obtain a white powdery solid, which is then pulverized to obtain the light stabilizer.

[0023] In an industrial reactor protected from light, water, and nitrogen, crude industrial chloromethyl ethyl ether was added. First, the light stabilizer was added at 0.12% of the crude chloromethyl ethyl ether mass, and the stirring speed was controlled at 200 r / min for 30 min until completely dissolved. Then, epoxidized soybean oil was added at 0.2% of the crude chloromethyl ethyl ether mass, and the mixture was stirred for another 20 min until homogeneous. The reactor was sealed, and the air inside was replaced with nitrogen three times, each time purging to 0.3 MPa and maintaining the pressure for 10 min before venting. After the replacement was completed, the pressure inside the reactor was maintained at 0.05 MPa, and the reactor was allowed to stand at room temperature in the dark for 2 h to obtain chloromethyl ethyl ether with good photothermal stability.

[0024] Comparative Example 1 Preparation of Intermediate 1: 100 mL of ethanol, 22 g of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and 8 g of n-butylamine were added to a 250 mL four-necked flask equipped with a reflux dehydration device. The mixture was heated to 60 °C and reacted for 1 h. The temperature was then lowered to 0 °C using an ice-salt bath. 2 g of potassium borohydride was added in four batches, with an 8-min interval between each batch. The system temperature was maintained at 0 °C during the addition process. The reaction was continued at 0 °C for 0.5 h. The pH was adjusted to 2.0 by adding 5% citric acid aqueous solution. After removing the ethanol by rotary evaporation, the pH was adjusted to 9.0 by adding 10% sodium hydroxide aqueous solution. The mixture was extracted with dimethyl carbonate, 135 mL each time, for three extractions. The resulting yellow oily intermediate 1 was obtained by rotary evaporation (removing the ethanol by rotary evaporation under reduced pressure, with the evaporation temperature controlled at 37 °C and the vacuum degree at 0.09 MPa). Preparation of the light stabilizer precursor: Intermediate 1 and hexamethylenediamine piperidine were added to a 500 mL autoclave at a mass ratio of 1:2.2. 250 mL of trimethylbenzene was added, and the autoclave was sealed. The air inside the autoclave was replaced with nitrogen three times (the specific operation of nitrogen replacement is as follows: nitrogen is charged into the autoclave to 0.25 MPa, maintained for 8 min, and then vented. This is repeated 3 times). The temperature was raised to 80 °C and reacted for 2 h. After cooling, the autoclave was opened, nitrogen was charged to 0.6 MPa, and the autoclave was heated and stirred and then heated to 170 °C and reacted for 6 h. After cooling, venting, and opening the autoclave, the reaction solution was filtered. The organic phase was washed twice with a 10% sodium chloride aqueous solution, with 125 mL of water used for each wash. The solvent was distilled off under reduced pressure (the vacuum degree was 0.09 MPa and the distillation temperature was 90 °C) to obtain a white solid as the light stabilizer precursor. Preparation of light stabilizer: Add 100 mL of anhydrous dimethyl carbonate to a 250 mL four-necked flask, add all the above light stabilizer precursors, stir until completely dissolved, slowly add 9 mL of acetic anhydride dropwise at room temperature, after the addition is complete, raise the temperature to 40 °C and react at a constant temperature for 1.5 h, slowly add distilled water dropwise to the reaction solution, wash twice, 50 mL each time, to remove excess acetic anhydride and the generated acetic acid, dry the organic phase with anhydrous magnesium sulfate, filter, remove dimethyl carbonate by rotary evaporation under reduced pressure, and obtain a white powder solid, which is then pulverized to obtain the light stabilizer.

[0025] In an industrial reactor protected from light, water, and nitrogen, crude industrial chloromethyl ethyl ether was added. First, the light stabilizer was added at 0.06% of the crude chloromethyl ethyl ether mass, and the stirring speed was controlled at 180 r / min for 25 min until completely dissolved. Then, epoxidized soybean oil was added at 0.1% of the crude chloromethyl ethyl ether mass, and stirring was continued for 17 min until uniformly mixed. The reactor was sealed, and the air inside was replaced with nitrogen three times, each time purging nitrogen to 0.2 MPa and maintaining this pressure for 8 min before venting. After the replacement was completed, the pressure inside the reactor was maintained at 0.03 MPa, and the reactor was allowed to stand at room temperature in the dark for 1.5 h to obtain chloromethyl ethyl ether with good photothermal stability.

[0026] Comparative Example 2 Preparation of intermediate 1: Add 90 mL of diethyl ether to a 250 mL four-necked flask, cool to below 5 °C in an ice bath, add 9 g of trichloroisocyanuric acid, stir well, and then add 8 mL of 20% sodium hydroxide aqueous solution dropwise. After the addition is complete, continue the reaction for 3 h. Transfer the reaction solution to a separatory funnel and wash with water (the water washing process is: wash the reaction solution with deionized water 3 times, and the amount of water used for each wash is 65 mL). After drying, filtration and concentration, intermediate 1, a light yellow solid, is obtained. Preparation of the light stabilizer precursor: Intermediate 1 and hexamethylenediamine piperidine were added to a 500 mL autoclave at a mass ratio of 1:2.2. 250 mL of trimethylbenzene was added, and the autoclave was sealed. The air inside the autoclave was replaced with nitrogen three times (the specific operation of nitrogen replacement is as follows: nitrogen is charged into the autoclave to 0.25 MPa, maintained for 8 min, and then vented. This is repeated 3 times). The temperature was raised to 80 °C and reacted for 2 h. After cooling, the autoclave was opened, nitrogen was charged to 0.6 MPa, and the autoclave was heated and stirred and then heated to 170 °C and reacted for 6 h. After cooling, venting, and opening the autoclave, the reaction solution was filtered. The organic phase was washed twice with a 10% sodium chloride aqueous solution, with 125 mL of water used for each wash. The solvent was distilled off under reduced pressure (the vacuum degree was 0.09 MPa and the distillation temperature was 90 °C) to obtain a white solid as the light stabilizer precursor. Preparation of light stabilizer: Add 100 mL of anhydrous dimethyl carbonate to a 250 mL four-necked flask, add all the above light stabilizer precursors, stir until completely dissolved, slowly add 9 mL of acetic anhydride dropwise at room temperature, after the addition is complete, raise the temperature to 40 °C and react at a constant temperature for 1.5 h, slowly add distilled water dropwise to the reaction solution, wash twice, 50 mL each time, to remove excess acetic anhydride and the generated acetic acid, dry the organic phase with anhydrous magnesium sulfate, filter, remove dimethyl carbonate by rotary evaporation under reduced pressure, and obtain a white powder solid, which is then pulverized to obtain the light stabilizer.

[0027] In an industrial reactor protected from light, water, and nitrogen, crude industrial chloromethyl ethyl ether was added. First, the light stabilizer was added at 0.06% of the crude chloromethyl ethyl ether mass, and the stirring speed was controlled at 180 r / min for 25 min until completely dissolved. Then, epoxidized soybean oil was added at 0.1% of the crude chloromethyl ethyl ether mass, and stirring was continued for 17 min until uniformly mixed. The reactor was sealed, and the air inside was replaced with nitrogen three times, each time purging nitrogen to 0.2 MPa and maintaining this pressure for 8 min before venting. After the replacement was completed, the pressure inside the reactor was maintained at 0.03 MPa, and the reactor was allowed to stand at room temperature in the dark for 1.5 h to obtain chloromethyl ethyl ether with good photothermal stability.

[0028] Performance testing I. The thermal stability of chloromethyl ethyl ether, which has good photothermal stability, prepared by the methods of Examples 1-3 and Comparative Examples 1-2 according to GB / T22232-2008 "Determination of Thermal Stability of Chemical Substances by Differential Scanning Calorimetry" was tested, and the DSC initial decomposition temperature was recorded. The results are shown in Table 1. Table 1 As shown in Table 1, the chloromethyl ethyl ether samples prepared using the photothermal stabilizer described in this invention all exhibited significantly higher DSC initial decomposition temperatures than the comparative examples. The initial decomposition temperatures of Examples 1-3 were 71℃, 73℃, and 68℃, respectively, all significantly higher than those of Comparative Example 1 (60℃) and Comparative Example 2 (62℃). Among them, Example 2 showed the best thermal stability, with an initial decomposition temperature of 73℃, which was 13℃ higher than that of Comparative Example 1 and 11℃ higher than that of Comparative Example 2.

[0029] The results in Table 1 show that the photothermal stabilizer selected in this invention can significantly increase the thermal decomposition temperature of chloromethyl ethyl ether, effectively inhibit its decomposition under heating conditions, and enhance the thermal stability and safety of the system during storage, transportation and processing.

[0030] II. The photostability of chloromethyl ethyl ether, prepared according to the methods of Examples 1-3 and Comparative Examples 1-2, with good photothermal stability, was tested according to GB / T16422.3-2022 "Laboratory Light Source Exposure Test Methods for Plastics - Part 3: Fluorescent Ultraviolet Lamps". The conditions were: UV irradiation for 168 hours. The purity retention rate of each group of samples was recorded, and the results are shown in Table 2. Table 2 As can be seen from Table 2, after treatment with the photothermal stabilizer provided by the present invention, the purity retention rate of chloromethyl ethyl ether under UV irradiation for 168 hours is significantly better than that of the comparative example.

[0031] The purity retention rates of Examples 1-3 of this invention were 95%, 97%, and 96%, respectively, all remaining above 95%, indicating that the sample structure remained stable and was not prone to photodegradation under prolonged ultraviolet light irradiation, demonstrating excellent photostability. Example 2 showed the best results, with a purity retention rate reaching 97%.

[0032] In contrast, the purity retention rates of Comparative Examples 1 and 2 were only 81% and 83%, respectively, which were significantly lower than those of the embodiments of the present invention. They were more prone to decomposition under ultraviolet light, their purity decreased rapidly, and their photostability was poor.

[0033] The results in Table 2 show that the photothermal stabilizer used in this invention can effectively inhibit the degradation reaction of chloromethyl ethyl ether under ultraviolet light, significantly improve its photostability, and extend its storage and use cycle under light, demonstrating outstanding stabilizing effect.

[0034] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether, characterized in that, Includes the following steps: Step S1, Preparation of Intermediate 1: Add 80-120 mL of ethanol, 20-25 g of 3,5-di-tert-butyl-4-hydroxybenzaldehyde and 6-10 g of n-butylamine to a 250 mL four-necked flask equipped with a reflux water separator. Heat to 60 °C and react for 1 h. Cool to 0 °C using an ice-salt bath. Add 1-3 g of potassium borohydride in batches and continue the reaction at 0 °C for 0.5 h. Add 5% citric acid aqueous solution to adjust the pH to 2.0-3.

0. After removing ethanol by rotary evaporation, adjust the pH to 8.0-9.0 using 10% sodium hydroxide aqueous solution. Extract with dimethyl carbonate, 120-150 mL each time, for 3 extractions. Obtain the yellow oily intermediate 1 by rotary evaporation. Step S2, Preparation of Intermediate 2: Add 80-100 mL of diethyl ether to a 250 mL four-necked flask, cool to below 5 °C in an ice bath, add 8-10 g of trichloroisocyanuric acid, stir well, and slowly add 30-45 mL of diethyl ether solution containing 10-15 g of intermediate 1. After the addition is complete, react for 2 h, then add 5-10 mL of 20% sodium hydroxide aqueous solution. After the addition is complete, continue to react for 3 h. Transfer the reaction solution to a separatory funnel, wash with water, and after drying, filtration, and concentration, obtain intermediate 2 as a light yellow solid. Step S3, Preparation of light stabilizer precursor: Intermediate 2 and hexamethylenediamine piperidine were added to a 500mL autoclave at a mass ratio of 1:2.

2. 200-300mL of trimethylbenzene was added, the autoclave was sealed, and the air inside was replaced with nitrogen three times. The temperature was raised to 80℃ and reacted for 2h. After cooling, the autoclave was opened, nitrogen was purged to 0.6MPa, and the autoclave was heated and stirred and heated to 170℃ for 6h. After cooling, releasing the gas, and opening the autoclave, the reaction solution was filtered. The organic phase was washed with a 10% sodium chloride aqueous solution, and the solvent was evaporated under reduced pressure to obtain a white solid as the light stabilizer precursor. Step S4, Preparation of light stabilizer: Add 100 mL of anhydrous dimethyl carbonate to a 250 mL four-necked flask, add all the above light stabilizer precursors, stir until completely dissolved, slowly add 8-10 mL of acetic anhydride dropwise at room temperature, after the addition is complete, raise the temperature to 40℃ and react at a constant temperature for 1.5 h, slowly add distilled water dropwise to the reaction solution, wash twice, 50 mL each time, to remove excess acetic anhydride and the generated acetic acid, dry the organic phase with anhydrous magnesium sulfate, filter, remove dimethyl carbonate by rotary evaporation under reduced pressure, and obtain a white powdery solid, which is then pulverized to obtain the light stabilizer. Step S5: In an industrial reactor protected from light, water, and nitrogen, add crude industrial chloromethyl ethyl ether. First, add the light stabilizer at 0.02%-0.12% of the crude chloromethyl ethyl ether mass, controlling the stirring speed at 150-200 r / min and stirring for 20-30 min until completely dissolved. Then, add an epoxy acid scavenger at 0.05%-0.2% of the crude chloromethyl ethyl ether mass and continue stirring for 15-20 min until uniformly mixed. Seal the reactor and replace the air inside with nitrogen 2-3 times, each time purging with nitrogen to 0.2-0.3 MPa, maintaining this pressure for 5-10 min before venting. After replacement, maintain the pressure inside the reactor at 0.02-0.05 MPa and let it stand at room temperature in the dark for 1-2 h to obtain chloromethyl ethyl ether with good photothermal stability.

2. The production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether according to claim 1, characterized in that, In step S1, the potassium borohydride is added in 3-5 batches, with an interval of 5-10 minutes between each batch, and the system temperature is kept at 0°C during the addition process.

3. The production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether according to claim 1, characterized in that, In step S1, ethanol is removed by rotary evaporation under reduced pressure. The rotary evaporation temperature is controlled at 35-40℃ and the vacuum degree is 0.08-0.1MPa.

4. The production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether according to claim 1, characterized in that, The dropping rate of the ether solution of intermediate 1 is 1-2 mL / min, and the system temperature is maintained at 0-5℃ during the dropping process.

5. The production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether according to claim 1, characterized in that, In step S2, the water washing process is as follows: wash the reaction solution with deionized water 2-3 times, with a water volume of 50-80 mL each time.

6. The production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether according to claim 1, characterized in that, In step S3, the specific operation of replacing air with nitrogen is as follows: fill the autoclave with nitrogen to 0.2-0.3 MPa, maintain for 5-10 minutes, and then vent. Repeat this process 3 times.

7. The production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether according to claim 1, characterized in that, In step S3, when the solvent is evaporated under reduced pressure, the vacuum degree is 0.09-0.1 MPa and the evaporation temperature is 80-100℃.

8. The production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether according to claim 1, characterized in that, In step S3, the organic phase is washed twice with a 10% sodium chloride aqueous solution, with each wash using 100-150 mL of water.

9. A production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether according to claim 1, characterized in that, In step S4, the rotary evaporation temperature is controlled at 55-65℃ and the vacuum degree is 0.08-0.1MPa.

10. A production method for improving the photothermal stability of industrial-grade chloromethyl ethyl ether according to claim 1, characterized in that, In step S5, the epoxy acid scavenger is epoxidized soybean oil.

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