Process for the preparation of the antioxidant ippd
By using a method of supporting noble metal catalysts on mesoporous carbon, the side reaction of acetone to isopropanol was suppressed under mild conditions, solving the problem of controlling side reactions in the synthesis of the antioxidant IPPD, improving reaction selectivity and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-12-03
- Publication Date
- 2026-06-05
AI Technical Summary
In the existing technology, the side reaction of acetone hydrogenation to isopropanol in the synthesis of the antioxidant IPPD is difficult to control, which leads to increased consumption of reaction raw materials and increased production costs. In addition, copper-based catalysts are prone to introducing impurities that affect product quality, and there is still room for improvement in the selectivity of precious metal catalysts.
Mesoporous carbon was used as a support to support noble metal catalysts. By carrying out the hydrogenation reaction under mild conditions, the side reaction of acetone to isopropanol was suppressed, the ketone-to-alcohol ratio of the hydrogenation reaction was increased, and the post-processing steps were reduced.
The effective inhibition of acetone to isopropanol formation under mild conditions improves the selectivity of hydrogenation reaction of the antioxidant IPPD, reduces energy consumption and production costs, and enhances market competitiveness.
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Figure BDA0005167814250000011
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic synthesis technology, and specifically to a method for preparing the antioxidant IPPD. Background Technology
[0002] Rubber and its products are prone to aging during long-term storage and use, leading to changes in their properties and affecting their performance. Adding antioxidants can effectively delay or inhibit the aging process of rubber, thereby extending the service life of rubber and its products. IPPD, also known as 4010NA, is a pure white crystalline powder that easily oxidizes and discolors when exposed to air and sunlight. However, it possesses comprehensive protective properties and is a versatile and excellent antioxidant for natural rubber, synthetic rubber, and latex. It exhibits high ozone resistance and flexural strength, and inhibits the activity of heat, oxygen, and harmful metals (such as copper and manganese). It is currently widely used in tire treads and sidewalls, hoses, cables, and seals.
[0003] Currently, commonly used synthetic methods for IPPD include the reduction hydrocarbon method, phenolamine condensation method, hydroxylamine reduction hydrocarbon method, and quinone imine condensation method. The current market preparation method is still dominated by the reduction hydrocarbon method, a two-step method using RT-peptide and acetone as raw materials. The specific reaction equation is shown below:
[0004]
[0005] In the above reaction process, the most significant side reaction is the hydrogenation reduction of acetone to isopropanol. On one hand, this consumes the acetone used as a reactant, affecting the condensation hydrogenation process of RT-based acetone and acetone. On the other hand, the generated isopropanol needs to be separated by distillation and then subjected to high-temperature catalytic dehydrogenation to regenerate acetone before it can participate in the next reaction cycle, significantly increasing production costs. The reduction hydrocarbon method mainly uses catalysts for hydrogenation. Currently, catalysts are divided into copper-based catalysts and noble metal catalysts. Copper-based catalysts dominate the market due to their low cost. However, with increasingly stringent requirements for antioxidant quality, copper-based catalysts are prone to amplifying side reactions and introducing copper into the product, leading to reduced product quality. This has gradually limited the production of IPPD using copper-based catalysts. The application of noble metal catalysts in the reduction hydrocarbon method is gradually increasing, and they have significantly improved reaction selectivity compared to copper-based catalysts. However, further improvements are needed in suppressing the ketone-to-alcohol ratio side reaction. Summary of the Invention
[0006] The purpose of this invention is to overcome the problem of uncontrollable side reactions in the synthesis of the antioxidant IPPD during the existing technology, specifically the hydrogenation of acetone to isopropanol. This invention provides a method for preparing the antioxidant IPPD, which uses a noble metal catalyst to suppress the ketone-to-alcohol side reaction under milder reaction conditions, increases the ketone-to-alcohol ratio in the IPPD hydrogenation reaction, reduces post-processing, and simplifies the operation. To achieve the above objective, this invention provides a method for preparing the antioxidant IPPD, comprising:
[0007] RT-based peroxide, acetone, and a noble metal catalyst are mixed, followed by the introduction of hydrogen gas and a hydrogenation reaction at 20-60°C. The noble metal catalyst contains mesoporous carbon and a noble metal component supported on the mesoporous carbon; the specific surface area of the mesoporous carbon is 2000-3000 m². 2 / g, pore volume 2-3cm³ 3 / g.
[0008] Preferably, the method further includes preparing the noble metal catalyst according to the following steps: activating mesoporous carbon, then impregnating it with a noble metal salt solution, adjusting the pH value to 6.5-7.5 with sodium carbonate solution, and reducing the resulting mixture with sodium borohydride solution to obtain the noble metal catalyst.
[0009] Preferably, the specific process for activating mesoporous carbon includes immersing the mesoporous carbon in an acid solution.
[0010] Preferably, the acid solution is at least one of hydrochloric acid, sulfuric acid, and nitric acid.
[0011] Preferably, the concentration of the acid solution is 3-12 wt%.
[0012] Preferably, in the noble metal salt solution, the noble metal salt is a water-soluble platinum salt, preferably chloroplatinic acid.
[0013] Preferably, the concentration of the noble metal salt solution is 1-10 wt%.
[0014] Preferably, the ratio of the mesoporous carbon to the noble metal salt solution is (100-200) g: 100 mL.
[0015] Preferably, the concentration of the sodium carbonate solution is 8-15 wt%.
[0016] Preferably, the concentration of the sodium borohydride solution is 4-10 wt%.
[0017] Preferably, the conditions for the reduction reaction include: a temperature of 20-60°C and a time of 1-5 hours.
[0018] Preferably, the content of the noble metal in the noble metal catalyst is 1-4 wt%.
[0019] Preferably, the mass ratio of the RT-peptide to the acetone is 1:(0.5-1.5).
[0020] Preferably, the mass ratio of the noble metal catalyst to the RT ester is (2-4):100.
[0021] Preferably, the hydrogenation reaction process includes: introducing nitrogen gas and maintaining a pressure of 0.4-0.6 MPa, then heating to 20-60°C, and then introducing hydrogen gas to maintain a pressure of 0.5-1.5 MPa and reacting for 0.5-10 h.
[0022] Compared with the prior art, the technical solution of the present invention has the following technical effects:
[0023] (1) Compared with traditional coconut shell activated carbon, the mesoporous carbon used in the preparation method of the antioxidant IPPD of the present invention has a higher specific surface area and pore volume, and the noble metal catalyst of the present invention has a better catalytic effect under the same noble metal loading, thereby improving the ketone-to-alcohol ratio in the hydrogenation reaction of the antioxidant IPPD.
[0024] (2) Compared with existing copper-based catalysts and other precious metal catalyst systems, the precious metal catalyst described in this invention has better selectivity, effectively inhibits the hydrogenation of acetone to isopropanol, and the hydrogenation reaction conditions for preparing the antioxidant IPPD are milder, with lower reaction temperature and pressure, and can even be carried out at room temperature, saving energy consumption, reducing equipment investment and production costs. In the current fierce market, it has stronger market competitiveness and application value. Detailed Implementation
[0025] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.
[0026] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0027] The preparation method of the antioxidant IPPD of the present invention includes:
[0028] RT-based peroxide, acetone, and a noble metal catalyst are mixed, followed by the introduction of hydrogen gas and a hydrogenation reaction at 20-60°C. The noble metal catalyst contains mesoporous carbon and a noble metal component supported on the mesoporous carbon; the specific surface area of the mesoporous carbon is 2000-3000 m². 2 / g, pore volume 2-3cm³ 3 / g.
[0029] According to the method described in this invention, by using mesoporous carbon as a support and loading noble metal catalysts, the antioxidant IPPD can be prepared by catalytic hydrogenation under relatively mild conditions. This effectively inhibits the hydrogenation of acetone to isopropanol and improves the ketone-to-alcohol ratio in the hydrogenation reaction for preparing the antioxidant IPPD.
[0030] In the method described in this invention, the method may further include preparing the noble metal catalyst by the following steps: activating mesoporous carbon, then impregnating it in a noble metal salt solution, adjusting the pH value to 6.5-7.5 with sodium carbonate solution, and reducing the resulting mixture with sodium borohydride solution to obtain the noble metal catalyst.
[0031] In the method described in this invention, the activation process for removing ash from the surface of the mesoporous carbon preferably includes immersing the mesoporous carbon in an acid solution. More preferably, the activation process includes immersing the mesoporous carbon in an acid solution at 20-40°C for 2-4 hours, separating the solid phase by filtration and washing with water until the pH of the washing solution reaches 6.5-7.5, followed by drying at 30-50°C and a vacuum of 10-20 kPa for 6-10 hours. The acid solution can be at least one of hydrochloric acid, sulfuric acid, and nitric acid, preferably hydrochloric acid. The concentration of the acid solution can be 3-12 wt%, preferably 5-10 wt%. In this document, the vacuum degree is atmospheric pressure minus absolute pressure. The ratio of the mesoporous carbon to the acid solution can be (100-150) g: 100 mL, preferably (100-120) g: 100 mL.
[0032] In the method described in this invention, the noble metal salt in the noble metal salt solution can be a water-soluble platinum salt, preferably chloroplatinic acid. The concentration of the noble metal salt solution can be 1-10 wt%, preferably 2-8 wt%, and more preferably 2.1-6.3 wt%. The ratio of the mesoporous carbon to the noble metal salt solution can be (100-200) g: 100 mL, preferably (100-150) g: 100 mL.
[0033] In the method described in this invention, the impregnation conditions include: a temperature of 20-60°C, preferably 30-50°C; and a time of 1-5 hours, preferably 2-4 hours.
[0034] In the method described in this invention, in order to improve the catalytic performance of the noble metal catalyst, the concentration of the sodium carbonate solution is preferably 8-15 wt%, more preferably 8-12 wt%. Adjusting the pH value to 6.5-7.5 using the sodium carbonate solution is beneficial for the noble metal catalyst to catalyze the hydrogenation reaction to prepare the antioxidant IPPD.
[0035] In the method described in this invention, the concentration of the sodium borohydride solution can be 4-10 wt%, preferably 5-8 wt%. The volume ratio of the sodium borohydride solution to the noble metal salt solution can be (1-4):1, preferably (2-3):1. The conditions for the reduction reaction include: a temperature of 20-60℃, preferably 30-50℃; and a time of 1-5 h, preferably 2-4 h. The method may further include: separating the solid phase from the mixture obtained after the reduction reaction by vacuum filtration, washing with water until no chloride ions are present in the washing liquid, and then drying at a temperature of 30-50℃ and a vacuum of 10-20 kPa for 6-10 h.
[0036] In the method described in this invention, in order to improve the selectivity of the antioxidant IPPD, the content of the noble metal in the noble metal catalyst is preferably 1-4 wt%, more preferably 2-3 wt%. In a specific embodiment, the noble metal is platinum, and the content of platinum in the noble metal catalyst is 1-4 wt%. The noble metal catalyst can be reused after filtration and washing.
[0037] In the method described in this invention, the specific process of mixing RT-peptide, acetone and noble metal catalyst may include: adding the mixture of RT-peptide and acetone to a reaction vessel, then adding the noble metal catalyst, fixing and sealing it, and checking the airtightness of the reaction vessel.
[0038] In the method described in this invention, the mass ratio of the RT-peptide to the acetone can be 1:(0.5-1.5), preferably 1:(0.8-1.2). The mass ratio of the noble metal catalyst to the RT-peptide can be (2-4):100, preferably (3-3.5):100. During the hydrogenation reaction, the hydrogen-to-oil ratio can be (500-1500):1, preferably (800-1200):1.
[0039] In the method described in this invention, the hydrogenation reaction process may include: introducing nitrogen gas and maintaining a pressure of 0.4-0.6 MPa, then heating to 20-60°C, then introducing hydrogen gas and maintaining a pressure of 0.5-1.5 MPa for 0.5-10 h. Preferably, the hydrogenation reaction process includes: introducing nitrogen gas and maintaining a pressure of 0.45-0.55 MPa, then heating to 30-40°C, then introducing hydrogen gas and maintaining a pressure of 0.8-1.2 MPa for 1-8 h. The hydrogenation reaction can be carried out in a reaction vessel. In a specific embodiment, the hydrogenation reaction process includes: purging air with nitrogen and maintaining a pressure of 0.4-0.6 MPa; stirring at a stirring rate of 100-300 r / min for 0.5-1.5 h and heating to 20-60 °C; then purging with hydrogen and purging 4-5 times to maintain a pressure of 0.5-1.5 MPa; and reacting for 0.5-10 h until the pressure stabilizes. In this document, pressure refers to gauge pressure.
[0040] In the method described in this invention, the method may further include: depressurizing the mixture obtained after the hydrogenation reaction to atmospheric pressure and cooling it to 20-30°C, then separating the solid phase by vacuum filtration and washing it with water for 0.5-1.5 h, and then drying it for 6-8 h at a temperature of 30-50°C and a vacuum of 10-20 kPa.
[0041] In some embodiments, the preparation method of the antioxidant IPPD of the present invention includes the following steps:
[0042] (1) The mesoporous carbon is soaked in an acid solution at 20-40℃ for 2-4 hours. The solid phase is separated by filtration and washed with water until the pH of the washing solution is 6.5-7.5. Then, it is dried at 30-50℃ and a vacuum of 10-20 kPa for 6-10 hours. Next, it is impregnated in a noble metal salt solution with a concentration of 1-10 wt% at 20-60℃ for 1-5 hours. Then, the pH is adjusted to 6.5-7.5 with a sodium carbonate solution with a concentration of 8-15 wt%. The resulting mixture is then treated with a sodium carbonate solution with a concentration of 4-10 wt%. A sodium borohydride solution of t% is subjected to a reduction reaction at a temperature of 20-60℃ for 1-5 hours. The solid phase is separated from the mixture obtained after the reduction reaction by filtration and washed with water until no chloride ions are present in the washing liquid. Then, it is dried at a temperature of 30-50℃ and a vacuum degree of 10-20 kPa for 6-10 hours to obtain a noble metal catalyst. The ratio of the mesoporous carbon to the noble metal salt solution is (100-200) g: 100 mL; the volume ratio of the sodium borohydride solution to the noble metal salt solution is (1-4): 1.
[0043] (2) Add the mixture of RT-peptide and acetone to the reactor, then add the noble metal catalyst, fix and seal, check the airtightness of the reactor, purge with nitrogen to replace the air, and maintain the pressure at 0.4-0.6 MPa. Stir at a stirring rate of 100-300 r / min for 0.5-1.5 h and raise the temperature to 20-60℃. Then purge with hydrogen and purge 4-5 times to maintain the pressure at 0.5-1.5 MPa. Perform the hydrogenation reaction at 20-60℃ for 0.5-10 h until the pressure stabilizes. The mixture obtained after the hydrogenation reaction is depressurized to atmospheric pressure and cooled to 20-30℃. Then, the solid phase is separated by vacuum filtration and washed with water for 0.5-1.5h. Then, it is dried for 6-8h at a temperature of 30-50℃ and a vacuum of 10-20KPa. The mass ratio of the RT-peptide to the acetone is 1:(0.5-1.5); the mass ratio of the noble metal catalyst to the RT-peptide is (2-4):100; and the hydrogen-to-oil ratio is (500-1500):1.
[0044] The following examples further illustrate the preparation method of the antioxidant IPPD according to the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.
[0045] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.
[0046] Example 1
[0047] (1) Take 100g of mesoporous carbon (ordered mesoporous carbon CMK3, with a specific surface area of 2000-3000m²) 2 / g, pore volume 2-3cm³ 3 The platinum catalyst (containing 3 wt% platinum) was immersed in 100 mL of 8 wt% hydrochloric acid at 30 °C for 3 h. The solid phase was separated by filtration and washed with water until the pH of the washing solution was 7. Then, it was dried at 30 °C and 10 kPa for 10 h. Next, it was immersed in 100 mL of 6.3 wt% chloroplatinic acid aqueous solution at 40 °C for 2 h. Then, the pH was adjusted to 7 with 10 wt% sodium carbonate solution. The resulting mixture was reduced with 200 mL of 5 wt% sodium borohydride solution at 40 °C for 3 h. The solid phase was separated from the mixture after the reduction reaction by filtration and washed with water until no chloride ions were present in the washing solution. Then, it was dried at 40 °C and 10 kPa for 8 h to obtain the noble metal catalyst (the content of platinum in the noble metal catalyst is 3 wt%).
[0048] (2) A mixture of 100g RT-plast and 100g acetone was added to a reaction vessel, followed by 3.18g of the noble metal catalyst. The vessel was sealed and the airtightness of the reaction vessel was checked. Nitrogen was introduced to replace the air and the pressure was maintained at 0.5MPa. The mixture was stirred at a stirring rate of 200r / min for 1h and heated to 40℃. Hydrogen was then introduced and replaced 4 times to maintain a pressure of 1.0MPa. The hydrogenation reaction was carried out at 40℃ for 1h until the pressure stabilized. The mixture obtained after the hydrogenation reaction was depressurized to 101.325KPa and cooled to 25℃ to obtain a mixture. The mixture was analyzed by gas phase analysis and the results were recorded in Table 1. The solid phase was then separated by filtration and washed with water for 1.0h. The mixture was then dried at 40℃ and a vacuum of 10KPa for 6h. The noble metal catalyst was reused after filtration and washing. The hydrogen-to-oil ratio was 1000:1.
[0049] Example 2
[0050] (1) Take 100g of mesoporous carbon (ordered mesoporous carbon CMK3, with a specific surface area of 2000-3000m²) 2 / g, pore volume 2-3cm³ 3 The mixture (g) was immersed in 100 mL of 3 wt% sulfuric acid at 40 °C for 2 h. The solid phase was separated by filtration and washed with water until the pH of the washing solution was 6.5. Then, it was dried at 50 °C and 20 kPa for 6 h. Next, it was immersed in 100 mL of 2.1 wt% chloroplatinic acid aqueous solution at 60 °C for 1 h. Then, the pH was adjusted to 6.5 with 8 wt% sodium carbonate solution. The resulting mixture was reduced with 100 mL of 4 wt% sodium borohydride solution at 20 °C for 5 h. The solid phase was separated from the mixture after the reduction reaction by filtration and washed with water until no chloride ions were present in the washing solution. Then, it was dried at 30 °C and 10 kPa for 10 h to obtain the noble metal catalyst (the content of platinum in the noble metal catalyst is 1 wt%).
[0051] (2) A mixture of 100g RT-plast and 100g acetone was added to a reaction vessel, followed by 4.36g of the noble metal catalyst. The vessel was sealed and the airtightness of the reaction vessel was checked. Nitrogen was introduced to replace the air and the pressure was maintained at 0.4MPa. The mixture was stirred at a stirring rate of 100r / min for 1.5h and heated to 20℃. Hydrogen was then introduced and replaced 5 times to maintain the pressure at 0.5MPa. The hydrogenation reaction was carried out at 20℃ for 10h until the pressure stabilized. The mixture obtained after the hydrogenation reaction was depressurized to 101.325KPa and cooled to 20℃ to obtain a mixture. The mixture was analyzed by gas phase analysis and the results were recorded in Table 1. The solid phase was then separated by filtration and washed with water for 0.5h. The mixture was then dried at 30℃ and a vacuum of 10KPa for 8h. The noble metal catalyst was reused after filtration and washing. The hydrogen-to-oil ratio was 500:1.
[0052] Example 3
[0053] (1) Take 200g of mesoporous carbon (ordered mesoporous carbon CMK3, with a specific surface area of 2000-3000m²) 2 / g, pore volume 2-3cm³ 3 The platinum catalyst (containing 2.5 wt% platinum) was immersed in 100 mL of 12 wt% nitric acid at 20 °C for 4 h. The solid phase was separated by filtration and washed with water until the pH of the washing solution was 7.5. Then, it was dried at 40 °C and 10 kPa for 8 h. Next, it was immersed in 100 mL of 5.25 wt% chloroplatinic acid aqueous solution at 20 °C for 5 h. Then, the pH was adjusted to 7.5 with 15 wt% sodium carbonate solution. The resulting mixture was reduced with 400 mL of 10 wt% sodium borohydride solution at 60 °C for 1 h. The solid phase was separated from the mixture after the reduction reaction by filtration and washed with water until no chloride ions were present in the washing solution. Then, it was dried at 50 °C and 20 kPa for 6 h to obtain the noble metal catalyst (the content of platinum in the noble metal catalyst is 2.5 wt%).
[0054] (2) A mixture of 100g RT-plast and 150g acetone was added to a reactor, followed by 2.38g of the noble metal catalyst. The reactor was sealed and the airtightness was checked. Nitrogen was introduced to replace the air, and the pressure was maintained at 0.6MPa. The reactor was stirred at a stirring rate of 300r / min for 0.5h and heated to 60℃. Hydrogen was then introduced and replaced four times to maintain a pressure of 1.5MPa. The hydrogenation reaction was carried out at 60℃ for 0.5h until the pressure stabilized. The mixture obtained after the hydrogenation reaction was depressurized to 101.325KPa and cooled to 30℃ to obtain a mixture. The mixture was analyzed by gas phase analysis, and the results were recorded in Table 1. The solid phase was then separated by filtration and washed with water for 1.5h. The mixture was then dried at 50℃ and a vacuum of 20KPa for 6h. The noble metal catalyst was reused after filtration and washing. The hydrogen-to-oil ratio was 1500:1.
[0055] Example 4
[0056] The method was carried out according to Example 1, except that 100g of acetone was replaced with 50g of acetone. The results are shown in Table 1.
[0057] Example 5
[0058] The method was carried out according to Example 1, except that 100g of acetone was replaced with 150g of acetone. The results are shown in Table 1.
[0059] Example 6
[0060] The method of Example 1 was followed, except that in step (1), the noble metal catalyst (the content of platinum in the noble metal catalyst was 1 wt%) was prepared according to Example 2, and the amount of noble metal catalyst was changed to 2.12 g. The results are shown in Table 1.
[0061] Example 7
[0062] (1) Take 100g of mesoporous carbon (ordered mesoporous carbon CMK3, with a specific surface area of 2000-3000m²) 2 / g, pore volume is 2-3m³ 3The mixture (g) was immersed in 100 mL of 8 wt% hydrochloric acid at 30 °C for 3 h. The solid phase was separated by filtration and washed with water until the pH of the washing solution was 7. Then, it was dried at 40 °C and 10 kPa for 8 h. Next, it was immersed in 100 mL of 6 wt% chloroplatinic acid aqueous solution at 40 °C for 2 h. Then, the pH was adjusted to 7 with 10 wt% sodium carbonate solution. The resulting mixture was reduced with 200 mL of 5 wt% sodium borohydride solution at 40 °C for 3 h. The solid phase was separated from the mixture after the reduction reaction by filtration and washed with water until no chloride ions were present in the washing solution. Then, it was dried at 40 °C and 10 kPa for 8 h to obtain the noble metal catalyst (the content of platinum in the noble metal catalyst is 3 wt%).
[0063] (2) A mixture of 100g RT-plast and 100g acetone was added to a reactor, followed by 3.18g of the noble metal catalyst. The reactor was sealed and the airtightness was checked. Nitrogen was introduced to replace the air, and the pressure was maintained at 0.5MPa. The mixture was stirred at a stirring rate of 200r / min for 1h and heated to 30℃. Hydrogen was then introduced and replaced 4 times to maintain a pressure of 1.0MPa. The hydrogenation reaction was carried out at 30℃ for 1h until the pressure stabilized. The mixture obtained after the hydrogenation reaction was depressurized to 101.325KPa and cooled to 25℃ to obtain a mixture. The mixture was analyzed by gas phase analysis, and the results were recorded in Table 1. The solid phase was then separated by filtration and washed with water for 1.0h. The mixture was then dried at 40℃ and a vacuum of 10KPa for 6h. The noble metal catalyst was reused after filtration and washing. The hydrogen-to-oil ratio was 1000:1.
[0064] Example 8
[0065] The procedure was carried out according to Example 1, except that the temperature of the hydrogenation reaction was changed from 40°C to 60°C. The results are shown in Table 1.
[0066] Example 9
[0067] The method was carried out according to Example 1, except that the pressure maintained by introducing hydrogen gas and purging it four times was changed from 1.0 MPa to 0.8 MPa. The results are shown in Table 1.
[0068] Example 10
[0069] The method was carried out according to Example 1, except that the pressure maintained by introducing hydrogen gas and purging it four times was changed from 1.0 MPa to 1.2 MPa. The results are shown in Table 1.
[0070] Example 11
[0071] The procedure was carried out according to Example 10, except that the hydrogenation reaction time was changed from 1 hour to 2 hours. The results are shown in Table 1.
[0072] Example 12
[0073] The procedure was carried out according to Example 10, except that the hydrogenation reaction time was changed from 1 hour to 4 hours. The results are shown in Table 1.
[0074] Example 13
[0075] The procedure was carried out according to Example 10, except that the hydrogenation reaction time was changed from 1 hour to 8 hours. The results are shown in Table 1.
[0076] Comparative Example 1
[0077] The method of Example 1 was followed, except that the mesoporous carbon was replaced with coconut shell activated carbon (specific surface area of 1000-2000 m²). 2 / g, pore volume 1-2cm³ 3 / g). The results are shown in Table 1.
[0078] Comparative Example 2
[0079] The method was carried out according to Example 1, except that the mesoporous carbon was replaced with ZSM-5 molecular sieve. The results are shown in Table 1.
[0080] In this invention, the mixtures obtained in Examples 1-13 and Comparative Examples 1-2 were tested using a gas chromatograph (Agilent 7890A) with gas chromatography analysis. The contents of RT-perose, the antioxidant IPPD, and the ketone-to-alcohol ratio were measured. The gas chromatography analysis method was performed in accordance with the national standard GB / T 8828-2003. A high ketone-to-alcohol ratio indicates that the side reaction of acetone hydrogenation to isopropanol was suppressed.
[0081] Table 1
[0082] serial number Keto-alcohol ratio Example 1 99.8 / 0.2 Example 2 97.8 / 2.8 Example 3 98.5 / 1.5 Example 4 99.5 / 0.5 Example 5 98.6 / 1.4 Example 6 99.2 / 0.8 Example 7 99.7 / 0.3 Example 8 98.2 / 1.8 Example 9 99.4 / 0.6 Example 10 98.1 / 1.9 Example 11 99.1 / 0.9 Example 12 98.4 / 1.6 Example 13 97.9 / 2.1 Comparative Example 1 95.8 / 4.2 Comparative Example 2 88 / 12
[0083] As can be seen from the results in Table 1, the embodiments using the preparation method of the antioxidant IPPD described in this invention have better selectivity, effectively inhibit the hydrogenation of acetone to generate isopropanol, increase the ketone-to-alcohol ratio in the hydrogenation reaction of antioxidant IPPD, reduce post-processing of the reaction, and simplify the operation.
[0084] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.
Claims
1. A method for preparing the antioxidant IPPD, characterized in that, The method includes: RT-based peroxide, acetone, and a noble metal catalyst are mixed, followed by the introduction of hydrogen gas and a hydrogenation reaction at 20-60°C. The noble metal catalyst contains mesoporous carbon and a noble metal component supported on the mesoporous carbon. The specific surface area of the mesoporous carbon is 2000-3000 m². 2 / g, pore volume 2-3cm³ 3 / g.
2. The method according to claim 1, characterized in that, The method further includes preparing the noble metal catalyst by following these steps: activating mesoporous carbon, then impregnating it with a noble metal salt solution, adjusting the pH value to 6.5-7.5 with sodium carbonate solution, and reducing the resulting mixture with sodium borohydride solution to obtain the noble metal catalyst.
3. The method according to claim 2, characterized in that, The specific process for activating mesoporous carbon includes: immersing the mesoporous carbon in an acid solution; Preferably, the acid solution is at least one selected from hydrochloric acid, sulfuric acid, and nitric acid; Preferably, the concentration of the acid solution is 3-12 wt%.
4. The method according to claim 2 or 3, characterized in that, In the noble metal salt solution, the noble metal salt is a water-soluble platinum salt, preferably chloroplatinic acid; Preferably, the concentration of the noble metal salt solution is 1-10 wt%.
5. The method according to any one of claims 2-4, characterized in that, The ratio of the amount of mesoporous carbon to the amount of noble metal salt solution is (100-200) g: 100 mL.
6. The method according to any one of claims 2-5, characterized in that, The concentration of the sodium carbonate solution is 8-15 wt%.
7. The method according to any one of claims 2-6, characterized in that, The concentration of the sodium borohydride solution is 4-10 wt%. Preferably, the conditions for the reduction reaction include: a temperature of 20-60°C and a time of 1-5 hours.
8. The method according to any one of claims 1-7, characterized in that, The content of the precious metal in the precious metal catalyst is 1-4 wt%.
9. The method according to any one of claims 1-8, characterized in that, The mass ratio of the RT-peptide to the acetone is 1:(0.5-1.5); Preferably, the mass ratio of the noble metal catalyst to the RT ester is (2-4):
100.
10. The method according to any one of claims 1-9, characterized in that, The hydrogenation reaction process includes: introducing nitrogen gas and maintaining a pressure of 0.4-0.6 MPa, then heating to 20-60°C, then introducing hydrogen gas to maintain a pressure of 0.5-1.5 MPa and reacting for 0.5-10 h.