Method for producing polymerization inhibitor

Abstract

Provided is a method for producing a polymerization inhibitor. By using bis(2,2,6,6-tetramethylpiperidinyl)sebacate and 30% hydrogen peroxide as reaction raw materials, and methacrylic acid as a reaction solvent, under the condition of palladium tetraaminodicarbonate serving as a catalyst, bis(2,2,6,6-tetramethylpiperidinyl)sebacate nitroxide free radicals are prepared. Using methacrylic acid as a reaction solvent can increase the product yield, reduce the production cost, improve the economic benefit, reduce the resource consumption on the environment, and achieve sustainable and environmentally friendly production; and using palladium tetraaminodicarbonate as a catalyst can promote the progress of the reaction, and the catalyst can be recycled during the reaction process, thereby reducing the production cost, such that the method is suitable for large-scale production of a polymerization inhibitor.

Description

A method for producing a polymerization inhibitor Technical Field

[0001] The present invention relates to the field of production technology, in particular to a method for producing a polymerization inhibitor. Background Art

[0002] Inhibitor 706, chemically known as bis(2,2,6,6-tetramethylpiperidinyl) sebacate nitroxide, is a stable nitroxide radical with unpaired electrons. As an important industrial additive, it is commonly used to prevent polymerization. Inhibitor molecules participate in chain radical reactions, forming non-radical species or low-activity free radicals that cannot initiate polymerization, thereby preventing polymerization. At present, the production method of polymerization inhibitor 706 has two: route 1 is to use 2,2,6,6-tetramethyl-4-hydroxypiperidinyl nitroxide free radical and dimethyl sebacate to react, and the reaction needs to add excessive 2,2,6,6-tetramethyl-4-hydroxypiperidinyl nitroxide free radical, causing the cost of raw materials to be wasted, and unreacted raw materials can remain in the product, causing the decline of product content, therefore, the route is not suitable for later stage industrial production; route 2 is to use bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate and hydrogen peroxide as raw material, using 95% ethanol as reaction solvent, sodium tungstate as catalyst, in operating process because the oxygen on the ethanol hydroxyl group has a lone pair of electrons, has very strong nucleophilicity, easily nucleophilic substitution reaction occurs, generates 2,2,6,6-tetramethyl-4-hydroxypiperidinyl nitroxide free radical and diethyl sebacate, causing product yield to reduce, and there is impurity to produce. In view of this, the present invention proposes a production method of polymerization inhibitor.

[0003] Summary of the Invention

[0004] The object of the present invention is to provide a method for producing a polymerization inhibitor to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for producing a polymerization inhibitor is as follows:

[0007] S1: Add bis(2,2,6,6-tetramethylpiperidinyl) sebacate and 30% hydrogen peroxide to a reaction flask, and simultaneously add a reaction solvent and a catalyst to the reaction flask, and heat the reaction flask to 70°C;

[0008] S2: Slowly add 30% hydrogen peroxide to the reaction bottle while controlling the temperature of the reaction bottle;

[0009] S3: During the reaction, the reaction was monitored using high performance liquid chromatography to obtain the reaction endpoint;

[0010] S4: After reaching the end point of the reaction, manganese dioxide was added, stirred, and then filtered to remove the manganese dioxide silica-aluminum zeolite;

[0011] S5: The obtained reaction mother liquor is subjected to reduced pressure distillation. When the temperature and pressure of the reaction liquid reach appropriate conditions, the distillation is stopped, the reaction liquid is filtered, and the desired polymerization inhibitor is obtained after drying. Preferably, the reaction solvent is methacrylic acid. Among them, methacrylic acid is a polar solvent with strong dissolving power, which can effectively dissolve bis(2,2,6,6-tetramethylpiperidinyl)sebacate and 30% hydrogen peroxide, promoting the reaction between the reactants; methacrylic acid has the ability to effectively improve the dispersibility of the reactants in the solution, making the reaction more uniform; methacrylic acid, as an aprotic solvent, can effectively reduce the interaction between the reactants, thereby making the reaction easier to proceed, and methacrylic acid can also be used as a catalyst to effectively accelerate the reaction and improve the efficiency of the reaction. Preferably, the catalyst is tetraamino palladium dihydrogen carbonate, and the tetraamino palladium dihydrogen carbonate is fixed in the zeolite, and the specific steps of its fixation are: first, the silica-aluminum zeolite is cleaned with hydrochloric acid at a concentration of 20%, and then the residual hydrochloric acid is washed away with distilled water; the tetraamino palladium dihydrogen carbonate is dissolved in deionized water to form a solution, and the treated zeolite is immersed in the solution for 48 hours to allow the palladium ions to be fully adsorbed on the zeolite carrier. Subsequently, the zeolite carrier is rinsed with deionized water to remove excess tetraamino palladium dihydrogen carbonate solution, and then the zeolite is placed in a freeze dryer and dried for 24 hours. After drying, the catalyst used in the experiment is obtained. Wherein, tetraamino palladium dicarbonate has higher catalytic efficiency as catalyst, can accelerate reaction rate, improve production efficiency, and the catalyst has good thermal stability in the reaction process, and tolerates a wide temperature range, which is conducive to continuous production; tetraamino palladium dicarbonate has higher activity, can reduce the activation energy of reaction, and makes the reaction easier to carry out; the catalyst has good selectivity, can improve the yield of target product, reduce the generation of by-products, and the catalyst can be recycled in the reaction process, reducing production costs; and compared to traditional catalysts, tetraamino palladium dicarbonate is more environmentally friendly, and the harmful substances generated during use are less; tetraamino palladium dicarbonate is fixed on silica-aluminum zeolite, can prevent the dissolution or loss of catalyst, so that catalyst can be used repeatedly, reducing the cost of catalyst; and the selectivity of the tetraamino palladium dicarbonate fixed on silica-aluminum zeolite can be improved, and catalyst more selectively catalyzes target reaction, reduces the generation of side reactions, and improves the efficiency of catalytic reaction. As preferably, the mass ratio of described bis (2,2,6,6-tetramethylpiperidyl) sebacate and 30% hydrogen peroxide is 1:0.8-2.Among them, when the mass of bis(2,2,6,6-tetramethylpiperidinyl) sebacate is too high, the effective concentration of 30% hydrogen peroxide will be reduced, thereby slowing down the reaction rate; excessive bis(2,2,6,6-tetramethylpiperidinyl) sebacate may also lead to reduced selectivity of the reaction, resulting in side reactions or products different from those expected, and unreacted bis(2,2,6,6-tetramethylpiperidinyl) sebacate will be doped in the product, reducing the purity of the product.

[0012] Preferably, the mass ratio of the bis(2,2,6,6-tetramethylpiperidinyl) sebacate to the reaction solvent is 1:1.5-4. If the mass of the reaction solvent is too low, the solubility of the bis(2,2,6,6-tetramethylpiperidinyl) sebacate will be reduced, the reactants will not be effectively dissolved, and the reaction will be affected. If the mass of the reaction solvent is too high, the neutrality of the reaction system will deteriorate, affecting the reaction and the formation of the product.

[0013] Preferably, the ratio of bis(2,2,6,6-tetramethylpiperidinyl) sebacate to catalyst is 1:0.01-0.1. When the catalyst dosage is too high, the catalyst that cannot fully participate in the reaction may be wasted, and the unreacted catalyst may remain in the product in an unreacted form, resulting in a decrease in the purity of the product.

[0014] Preferably, the dropping time in S2 is 6-10 hours, and the temperature is controlled at 65-75°C.

[0015] Preferably, the HPLC monitoring conditions in S3 are as follows: chromatographic column specifications: Shimadzu C18, 5 μm, 250 mm; mobile phase: V (acetonitrile): V (2% ammonium bicarbonate aqueous solution) = 8:2; column temperature: 35°C; flow rate: 1 mL / min; detection wavelength: 225 nm; injection volume: 20 μL; analysis time: 40 min; reaction endpoint: sebacic acid (2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl)-(2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl) ester is less than 0.5%.

[0016] Preferably, the stirring time in S4 is 30-60 min, and the temperature of the reaction solution during filtration is greater than 60°C.

[0017] Preferably, the appropriate conditions in S5 are: temperature of 60° C. and pressure of -0.08 MPa.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] High-efficiency polymerization inhibitor 706 is prepared using bis(2,2,6,6-tetramethylpiperidinyl) sebacate and 30% hydrogen peroxide as the reaction materials, methacrylic acid as the reaction solvent, and tetraaminodihydrogen carbonate (PAD) as the catalyst. Methacrylic acid, a polar solvent with strong solubility, promotes the reaction. The PAD is fixed to a silica-alumina zeolite, resulting in excellent catalytic performance and recyclability, making it suitable for subsequent industrial production. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry. The methods in the following embodiments are all conventional methods in the art unless otherwise specified.

[0021] The following examples of the present invention are used:

[0022] Bis(2,2,6,6-tetramethylpiperidinyl) sebacate was purchased from Shanghai Jizhi Biochemical Technology Co., Ltd., CAS No.: 52829-07-9;

[0023] 30% hydrogen peroxide was purchased from Huainan Fangyuan Chemical Products Sales Co., Ltd., CAS No.: 7722-84-1;

[0024] Manganese dioxide was purchased from Hunan Daji Manganese Industry, CAS number: 1313-13-9;

[0025] Methacrylic acid was purchased from Jinan Century Tongda Chemical Co., Ltd., CAS No.: 79-41-4;

[0026] Tetraaminopalladium dihydrogen carbonate was purchased from Shanghai Fuze Trading Co., Ltd., CAS number: 134620-00-1;

[0027] Silica-alumina zeolite is purchased from Haoxiang, a strong supplier of thermal insulation building materials in Pingqiao District;

[0028] Hydrochloric acid was purchased from Jinan Sanen Chemical Co., Ltd., CAS number: 7647-01-0.

[0029] Example 1

[0030] In this embodiment, the catalyst fixing steps are as follows: the silica-alumina zeolite is cleaned with 20% hydrochloric acid, and then the residual hydrochloric acid is washed away with distilled water; tetraamino palladium dihydrogen carbonate is dissolved in deionized water to form a solution, and the treated zeolite is immersed in the solution for 48 hours to allow the palladium ions to be fully adsorbed on the zeolite carrier. Subsequently, the zeolite carrier is rinsed with deionized water to remove excess tetraamino palladium dihydrogen carbonate solution, and then the zeolite is placed in a freeze dryer for 24 hours. After drying, the catalyst used in the experiment is obtained.

[0031] The production method of polymerization inhibitor is as follows:

[0032] S1: 600 g of bis(2,2,6,6-tetramethylpiperidinyl) sebacate and 820 g of 30% hydrogen peroxide were added to a reaction flask, and 1200 g of methacrylic acid and 16.0 g of tetraaminopalladium dihydrogen carbonate fixed by silica-aluminum zeolite were added to the reaction flask, and the reaction flask was heated to 70° C.

[0033] S2: Slowly add 30% hydrogen peroxide to the reaction flask dropwise for 8 hours, and control the temperature of the reaction flask at 68°C;

[0034] S3: During the reaction, the reaction was monitored by high performance liquid chromatography to obtain the reaction endpoint, wherein the high performance liquid chromatography monitoring conditions were as follows: chromatographic column specifications: Shimadzu C18, 5 μm, 250 mm; mobile phase: V (acetonitrile): V (2% ammonium bicarbonate aqueous solution) = 8:2; column temperature: 35° C.; flow rate: 1 mL / min; detection wavelength: 225 nm; injection volume: 20 μL; analysis time: 40 min; reaction endpoint: sebacic acid (2,2,6,6-tetramethyl-4-piperidinyl-1-oxy)-(2,2,6,6-tetramethyl-4-piperidinyl-1-oxy) ester was less than 0.5%;

[0035] S4: After reaching the end point of the reaction, 1.6 g of manganese dioxide was added and stirred for 45 min. When the temperature of the reaction solution was greater than 60° C., the manganese dioxide and silica-aluminum zeolite were filtered out;

[0036] S5: The obtained reaction mother liquid is subjected to reduced pressure distillation. When the temperature and pressure of the reaction liquid reach 60° C. and −0.08 MPa, the distillation is stopped, the reaction liquid is filtered, and the test sample 1 is obtained after drying.

[0037] Example 2

[0038] In this embodiment, the catalyst fixing steps are as follows: the silica-alumina zeolite is cleaned with 20% hydrochloric acid, and then the residual hydrochloric acid is washed away with distilled water; tetraamino palladium dihydrogen carbonate is dissolved in deionized water to form a solution, and the treated zeolite is immersed in the solution for 48 hours to allow the palladium ions to be fully adsorbed on the zeolite carrier. Subsequently, the zeolite carrier is rinsed with deionized water to remove excess tetraamino palladium dihydrogen carbonate solution, and then the zeolite is placed in a freeze dryer for 24 hours. After drying, the catalyst used in the experiment is obtained.

[0039] The production method of polymerization inhibitor is as follows:

[0040] S1: 600 g of bis(2,2,6,6-tetramethylpiperidinyl) sebacate and 480 g of 30% hydrogen peroxide were added to a reaction flask, and 1200 g of methacrylic acid and 16.0 g of tetraaminopalladium dihydrogen carbonate fixed by silica-aluminum zeolite were added to the reaction flask, and the reaction flask was heated to 70° C.

[0041] S2: Slowly add 30% hydrogen peroxide to the reaction flask dropwise for 8 hours, and control the temperature of the reaction flask at 68°C;

[0042] S3: During the reaction, the reaction was monitored by high performance liquid chromatography to obtain the reaction endpoint, wherein the high performance liquid chromatography monitoring conditions were as follows: chromatographic column specifications: Shimadzu C18, 5 μm, 250 mm; mobile phase: V (acetonitrile): V (2% ammonium bicarbonate aqueous solution) = 8:2; column temperature: 35° C.; flow rate: 1 mL / min; detection wavelength: 225 nm; injection volume: 20 μL; analysis time: 40 min; reaction endpoint: sebacic acid (2,2,6,6-tetramethyl-4-piperidinyl-1-oxy)-(2,2,6,6-tetramethyl-4-piperidinyl-1-oxy) ester was less than 0.5%;

[0043] S4: After reaching the end point of the reaction, 1.6 g of manganese dioxide was added and stirred for 45 min. When the temperature of the reaction solution was greater than 60° C., the manganese dioxide and silica-aluminum zeolite were filtered out;

[0044] S5: The obtained reaction mother liquid is subjected to reduced pressure distillation. When the temperature and pressure of the reaction liquid reach 60° C. and −0.08 MPa, the distillation is stopped, the reaction liquid is filtered, and the test sample 2 is obtained after drying.

[0045] Example 3

[0046] In this embodiment, the catalyst fixing steps are as follows: the silica-alumina zeolite is cleaned with 20% hydrochloric acid, and then the residual hydrochloric acid is washed away with distilled water; tetraamino palladium dihydrogen carbonate is dissolved in deionized water to form a solution, and the treated zeolite is immersed in the solution for 48 hours to allow the palladium ions to be fully adsorbed on the zeolite carrier. Subsequently, the zeolite carrier is rinsed with deionized water to remove excess tetraamino palladium dihydrogen carbonate solution, and then the zeolite is placed in a freeze dryer for 24 hours. After drying, the catalyst used in the experiment is obtained.

[0047] The production method of polymerization inhibitor is as follows:

[0048] S1: 600 g of bis(2,2,6,6-tetramethylpiperidinyl) sebacate and 1200 g of 30% hydrogen peroxide were added to a reaction flask, and 1200 g of methacrylic acid and 16.0 g of tetraaminopalladium dihydrogen carbonate fixed by silica-aluminum zeolite were added to the reaction flask, and the reaction flask was heated to 70° C.

[0049] S2: Slowly add 30% hydrogen peroxide to the reaction flask dropwise for 8 hours, and control the temperature of the reaction flask at 68°C;

[0050] S3: During the reaction, the reaction was monitored by high performance liquid chromatography to obtain the reaction endpoint, wherein the high performance liquid chromatography monitoring conditions were as follows: chromatographic column specifications: Shimadzu C18, 5 μm, 250 mm; mobile phase: V (acetonitrile): V (2% ammonium bicarbonate aqueous solution) = 8:2; column temperature: 35° C.; flow rate: 1 mL / min; detection wavelength: 225 nm; injection volume: 20 μL; analysis time: 40 min; reaction endpoint: sebacic acid (2,2,6,6-tetramethyl-4-piperidinyl-1-oxy)-(2,2,6,6-tetramethyl-4-piperidinyl-1-oxy) ester was less than 0.5%;

[0051] S4: After reaching the end point of the reaction, 1.6 g of manganese dioxide was added and stirred for 45 min. When the temperature of the reaction solution was greater than 60° C., the manganese dioxide and silica-aluminum zeolite were filtered out;

[0052] S5: The obtained reaction mother liquid is subjected to reduced pressure distillation. When the temperature and pressure of the reaction liquid reach 60° C. and −0.08 MPa, the distillation is stopped, the reaction liquid is filtered, and the test sample 3 is obtained after drying.

[0053] Example 4

[0054] In this embodiment, the catalyst fixing steps are as follows: the silica-alumina zeolite is cleaned with 20% hydrochloric acid, and then the residual hydrochloric acid is washed away with distilled water; tetraamino palladium dihydrogen carbonate is dissolved in deionized water to form a solution, and the treated zeolite is immersed in the solution for 48 hours to allow the palladium ions to be fully adsorbed on the zeolite carrier. Subsequently, the zeolite carrier is rinsed with deionized water to remove excess tetraamino palladium dihydrogen carbonate solution, and then the zeolite is placed in a freeze dryer for 24 hours. After drying, the catalyst used in the experiment is obtained.

[0055] The production method of polymerization inhibitor is as follows:

[0056] S1: 600 g of bis(2,2,6,6-tetramethylpiperidinyl) sebacate and 1400 g of 30% hydrogen peroxide were added to a reaction flask, and 1200 g of methacrylic acid and 16.0 g of tetraaminopalladium dihydrogen carbonate fixed by silica-aluminum zeolite were added to the reaction flask, and the reaction flask was heated to 70° C.

[0057] S2: Slowly add 30% hydrogen peroxide to the reaction flask dropwise for 8 hours, and control the temperature of the reaction flask at 68°C;

[0058] S3: During the reaction, the reaction was monitored using high performance liquid chromatography to determine the reaction endpoint. The high performance liquid chromatography monitoring conditions were as follows: column specifications: Shimadzu C18, 5 μm, 250 mm; mobile phase: V (acetonitrile):V (2% ammonium bicarbonate aqueous solution) = 8:2; column temperature: 35°C; flow rate: 1 mL / min; detection wavelength: 225 nm; injection volume: 20 μL; analysis time: 40 min; reaction endpoint: sebacate (2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl)-(2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl) ester was less than 0.5%;

[0059] S4: After reaching the end point of the reaction, 1.6 g of manganese dioxide was added and stirred for 45 min. When the temperature of the reaction solution was greater than 60° C., the manganese dioxide and silica-aluminum zeolite were filtered out;

[0060] S5: The obtained reaction mother liquid is subjected to reduced pressure distillation. When the temperature and pressure of the reaction liquid reach 60° C. and −0.08 MPa, the distillation is stopped, the reaction liquid is filtered, and the test sample 4 is obtained after drying.

[0061] Example 5

[0062] In this embodiment, the catalyst fixing steps are as follows: the silica-alumina zeolite is cleaned with 20% hydrochloric acid, and then the residual hydrochloric acid is washed away with distilled water; tetraamino palladium dihydrogen carbonate is dissolved in deionized water to form a solution, and the treated zeolite is immersed in the solution for 48 hours to allow the palladium ions to be fully adsorbed on the zeolite carrier. Subsequently, the zeolite carrier is rinsed with deionized water to remove excess tetraamino palladium dihydrogen carbonate solution, and then the zeolite is placed in a freeze dryer for 24 hours. After drying, the catalyst used in the experiment is obtained.

[0063] The production method of polymerization inhibitor is as follows:

[0064] S1: 600 g of bis(2,2,6,6-tetramethylpiperidinyl) sebacate and 820 g of 30% hydrogen peroxide were added to a reaction flask, and 800 g of methacrylic acid and 16.0 g of tetraaminopalladium dihydrogen carbonate fixed by silica-aluminum zeolite were added to the reaction flask, and the reaction flask was heated to 70° C.

[0065] S2: Slowly add 30% hydrogen peroxide to the reaction flask dropwise for 8 hours, and control the temperature of the reaction flask at 68°C;

[0066] S3: During the reaction, the reaction was monitored by high performance liquid chromatography to obtain the reaction endpoint, wherein the high performance liquid chromatography monitoring conditions were as follows: chromatographic column specifications: Shimadzu C18, 5 μm, 250 mm; mobile phase: V (acetonitrile): V (2% ammonium bicarbonate aqueous solution) = 8:2; column temperature: 35° C.; flow rate: 1 mL / min; detection wavelength: 225 nm; injection volume: 20 μL; analysis time: 40 min; reaction endpoint: sebacic acid (2,2,6,6-tetramethyl-4-piperidinyl-1-oxy)-(2,2,6,6-tetramethyl-4-piperidinyl-1-oxy) ester was less than 0.5%;

[0067] S4: After reaching the end point of the reaction, 1.6 g of manganese dioxide was added and stirred for 45 min. When the temperature of the reaction solution was greater than 60° C., the manganese dioxide and silica-aluminum zeolite were filtered out;

[0068] S5: The obtained reaction mother liquid is subjected to reduced pressure distillation. When the temperature and pressure of the reaction liquid reach 60° C. and −0.08 MPa, the distillation is stopped, the reaction liquid is filtered, and the test sample 5 is obtained after drying.

[0069] Comparative Example 1

[0070] The same production method as in Example 1 was adopted, except that the catalyst in Comparative Example 1 was a silica-alumina zeolite without tetraaminopalladium dihydrogencarbonate, to obtain Test Sample 6.

[0071] Comparative Example 2

[0072] The same production method as in Example 1 was adopted, except that no methacrylic acid was added in Comparative Example 2, to obtain Test Sample 7.

[0073] The product yield and product content were calculated for the obtained test samples 1-7, and the results obtained are shown in the following table:

[0074] The data in the table above show that when methacrylic acid is used as the reaction solvent and tetraaminopalladium dihydrogen carbonate immobilized in silica-aluminum zeolite is used as the catalyst, the product yield and product content of the prepared product are both at a high level. Comparing test samples 1-3, it can be found that when the mass of the added 30% hydrogen peroxide changes, the effect on the product yield and product content is small. Comparing test samples 1 and 4, it can be found that when the mass of the added 30% hydrogen peroxide is too high, exceeding the appropriate proportion, the product yield and product content are greatly affected. Comparing test samples 1 and 5, it can be found that when the mass of the added methacrylic acid is too low, the product yield and product content are greatly affected. This is because when the mass of methacrylic acid is too low, the reaction between bis(2,2,6,6,-tetramethylpiperidinyl)sebacate and 30% hydrogen peroxide cannot proceed fully, resulting in a decrease in product yield and product content. Comparing test samples 1, 6, and 7, it can be found that when the catalyst and reaction solvent are lacking, the reaction is adversely affected, affecting the product purity and reaction rate, and having a significant impact on the product yield and product content.

[0075] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for producing a polymerization inhibitor, characterized in that The production method of the polymerization inhibitor is as follows: S1: Add bis(2,2,6,6-tetramethylpiperidinyl) sebacate and 30% hydrogen peroxide into a reaction bottle, and add a reaction solvent and a catalyst into the reaction bottle at the same time, and heat the reaction bottle to 70° C.; S2: Slowly add 30% hydrogen peroxide to the reaction bottle and control the temperature of the reaction bottle; S3: During the reaction, the reaction was monitored using high performance liquid chromatography to obtain the reaction endpoint; S4: After reaching the end point of the reaction, add manganese dioxide, stir, and then filter to remove the manganese dioxide silicon aluminum zeolite; S5: The obtained reaction mother liquid is subjected to reduced pressure distillation. When the temperature and pressure of the reaction liquid reach appropriate conditions, the distillation is stopped, the reaction liquid is filtered, and the desired polymerization inhibitor is obtained after drying.

2. The method for producing the polymerization inhibitor according to claim 1, characterized in that : The reaction solvent is methacrylic acid.

3. The method for producing the polymerization inhibitor according to claim 1, characterized in that The catalyst is tetraamino palladium dihydrogen carbonate, and the tetraamino palladium dihydrogen carbonate is fixed in the zeolite. The specific steps of its fixation are: first, the silica-alumina zeolite is washed with 20% hydrochloric acid, and then the residual hydrochloric acid is washed away with distilled water; the tetraamino palladium dihydrogen carbonate is dissolved in deionized water to prepare a solution, and the treated zeolite is soaked in the solution for 48 hours to allow the palladium ions to be fully adsorbed on the zeolite carrier. Subsequently, the zeolite carrier is rinsed with deionized water to remove excess tetraamino palladium dihydrogen carbonate solution, and then the zeolite is placed in a freeze dryer for 24 hours. After drying, the catalyst used in the experiment is obtained. .

4. The method for producing the polymerization inhibitor according to claim 1, characterized in that The mass ratio of the bis(2,2,6,6-tetramethylpiperidinyl)sebacate to 30% hydrogen peroxide is 1:0.8-2.

5. The method for producing the polymerization inhibitor according to claim 1, characterized in that :The mass ratio of the bis(2,2,6,6-tetramethylpiperidinyl)sebacate to the reaction solvent is 1:1.5-4.

6. The method for producing the polymerization inhibitor according to claim 1, characterized in that :The ratio of the bis(2,2,6,6-tetramethylpiperidinyl)sebacate to the catalyst is 1:0.01-0.

1.

7. The method for producing a polymerization inhibitor according to claim 1, characterized in that The dropping time in S2 is 6-10h, and the temperature is controlled at 65-75℃.

8. The method for producing a polymerization inhibitor according to claim 1, characterized in that The HPLC monitoring conditions in S3 are as follows: chromatographic column specifications: Shimadzu C18, 5 μm, 250 mm; mobile phase: V (acetonitrile): V (2% ammonium bicarbonate aqueous solution) = 8:2; column temperature: 35°C; flow rate: 1 mL / min; detection wavelength: 225 nm; injection volume: 20 μL; analysis time: 40 min; reaction endpoint: sebacic acid (2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl)-(2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl) ester is less than 0.5%.

9. The method for producing a polymerization inhibitor according to claim 1, characterized in that : The stirring time in S4 is 30-60 min, and the temperature of the reaction solution during filtration is greater than 60°C.

10. The method for producing a polymerization inhibitor according to claim 1, characterized in that : The appropriate conditions in S5 are: temperature of 60°C and pressure of -0.08Mpa.

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