Preparation method for synthesizing BIPB by using trifluoromethanesulfonic acid as catalyst

Abstract

The invention discloses a preparation method for synthesizing BIPB by using trifluoromethanesulfonic acid as a catalyst. The preparation method comprises the following steps: step S1, feeding raw materials; step S2, condensation reaction; and S3, carrying out post-treatment alkali washing. The method has the advantages that side reactions are reduced, the yield of BIPB reaches 96% or above, and the content of BIPB reaches 98 wt% or above; the reaction speed is greatly increased; the obtained bis (tert-butylperoxy isopropyl) benzene product is high in content / purity and almost white in color, recrystallization purification is not needed, the production process is shortened, and the production cost is greatly reduced; the dosage range of the catalyst enables the condensation reaction to be carried out more thoroughly, and the unforeseen circumstances that the condensation reaction is slowed down or stopped halfway due to the fact that DC contains trace alkaline substances can be avoided.

Description

Technical Field

[0001] This invention relates to the field of organic peroxide synthesis, specifically to a highly efficient and environmentally friendly catalyst and its application in BIPB synthesis. Background Technology

[0002] Di-tert-butyl peroxide (BIPB) is an important organic peroxide widely used in rubber vulcanization and polymer polymerization. Currently, the industrial synthesis of BIPB mainly involves the condensation reaction of tert-butyl hydroperoxide with cumene under acidic or metal catalysts.

[0003] CN 106588735 A discloses a sulfuric acid-catalyzed synthesis method for meta- and para-BIPB using US Patent 3787504 (1974), which yields anhydrous BIPB with a yield of 86.6%. The patent examples describe that the concentration of sulfuric acid below 60% or above 65% significantly affects the reaction yield. However, this method uses excessive sulfuric acid, generating 3 to 4 tons of dark red waste sulfuric acid (50%–60% concentration) for every ton of BIPB synthesized. This waste sulfuric acid contains tert-butyl hydroperoxide, BIPB, and various acid decomposition byproducts, which cannot be recycled and are difficult to treat and discharge, posing a significant environmental hazard.

[0004] CN 102796035 A, "A method for synthesizing meta- and para-mixed bis(tert-butylperoxide isopropyl)benzene," describes a method using bis(2-hydroxy-2-propyl)benzene and tert-butyl hydroperoxide as starting materials, employing 50%–52% perchloric acid as a catalyst and No. 6 solvent oil as a solvent, to perform a dehydration reflux condensation reaction under reduced pressure and nitrogen bubbling to obtain bis(tert-butylperoxide isopropyl)benzene. While this preparation method is easy to control, in actual production, the reaction time is long, there are many side reactions, and the reaction yield and product purity are not high.

[0005] Both of the above synthesis methods use acid as a catalyst, which can produce side reactions and harmful substances, resulting in low-quality BIPB.

[0006] CN 101544587 A describes a method for preparing bis(tert-butylperoxy)diisopropylbenzene, which uses a phosphotungstic heteropolyacid containing water of crystallization as a catalyst, and cyclohexane, di-tert-butylperoxide, or dichloromethane as solvents. 80% TBHP (containing 20% ​​water) is reacted with DC for 15 to 25 hours. The amount of heteropolyacid used is 1 / 5 to 1 of the mass of DC. The reaction temperature is 0 to 50°C, and the reaction yield is 50% to 66%. The examples do not describe the regeneration and recycling methods and effects of the phosphotungstic heteropolyacid as the catalyst. The BIPB preparation method has the following drawbacks: phosphotungstic heteropolyacid has strong hygroscopicity, making storage and use inconvenient; phosphotungstic heteropolyacid is expensive and used in large quantities, resulting in high raw material costs; used heteropolyacid catalysts, due to the adsorption of large amounts of water and peroxides, are prone to decomposition and explosion of residual peroxides during heating and dehydration activation, making recovery and regeneration difficult and thus difficult to recycle; the reaction time is 15 to 25 hours, which is too long and results in very low reaction efficiency; using the same amount of heteropolyacid catalyst as DC, reacting at 45°C for 16 hours, the BIPB yield is only 50.8% (Example 2); the low reaction yield indicates that its reaction conversion rate and selectivity are not high.

[0007] CN 119462463 A discloses "a method for synthesizing BIPB". This method uses tert-butyl hydroperoxide and di-(2-hydroxyisopropyl)benzene as starting materials. After the reaction is complete, trifluoromethanesulfonic acid is added as a catalyst. No auxiliary means are required, and side reactions and harmful substances generated by reactions with sulfuric acid, sodium perchlorate, etc. are eliminated. This method can obtain higher quality BIPB, improve the yield of BIPB, and is safer and more environmentally friendly, greatly reducing costs. However, this method does not require the use of solvents. Summary of the Invention

[0008] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0009] A method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst includes the following steps:

[0010] Step S1, Raw material feeding: Add No. 6 solvent oil to the reactor, stir, add TBHP tert-butyl hydrogen peroxide, extract fully, and let stand to separate layers and remove water;

[0011] Step S2, condensation reaction: DC [di-(2-hydroxyisopropyl)benzene] and trifluoromethanesulfonic acid aqueous solution are added to the dehydrated reaction solution. The vacuum pump is turned on to adjust the pressure inside the reactor to negative pressure and carry out the condensation reaction. During the condensation reaction, the gas phase is condensed and separated to obtain No. 6 solvent oil, which is refluxed back to the reactor. The content of intermediate monoperoxide is sampled and analyzed. When the content of intermediate monoperoxide is ≦1.5wt%, alkali solution is added to terminate the reaction. The mixture is then stirred and allowed to stand under controlled temperature.

[0012] Step S3, post-treatment alkaline washing: The above-mentioned static reaction solution is separated into liquids, and the upper organic phase is retained. The organic phase is then subjected to alkaline washing and water washing in sequence. The reaction wastewater is discharged to the wastewater treatment system in layers, and the upper organic phase is retained. The organic phase is concentrated under reduced pressure, cooled and solidified, and then crushed to obtain the finished product.

[0013] Furthermore, in step S1, the stirring speed is 200 rpm and the stirring temperature is controlled at 20-30℃; in step S2, DC [di-(2-hydroxyisopropyl)benzene] is added followed by trifluoromethanesulfonic acid aqueous solution; the condensation reaction temperature is 38-48℃; the vacuum regulating valve controls the reaction pressure of the condensation vessel at -(0.04-0.08) MPa; and the alkaline solution is a 3%-30% sodium hydroxide solution by mass concentration.

[0014] Preferably, the weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to No. 6 solvent oil is 100:200-400; the weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to TBHP (tert-butyl hydroperoxide) is 100:120-160; the weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to trifluoromethanesulfonic acid aqueous solution is 100:0.4-5; the weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to alkaline solution is 100:100-200; and the weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to washing water is 100:100-200.

[0015] Theoretically, the more TBHP, the better the synthesis of BIPB, resulting in higher quality BIPB. Therefore, the amount of TBHP added is generally excessive. This is mainly because the concentration of TBHP decreases as the reaction proceeds, making it increasingly difficult for TBHP to combine with DC and intermediate products. If there is too little TBHP, a large amount of intermediate products will be obtained, which cannot be further synthesized into BIPB, resulting in low product content. If there is too much TBHP, it will not significantly improve the quality of synthesized BIPB but will lead to excessively high production costs and excessively high TBHP content in wastewater, increasing wastewater treatment costs. Therefore, this invention uses a weight ratio of DC [di-(2-hydroxyisopropyl)benzene] to TBHP (tert-butyl hydroperoxide) of 100:120-160, which is the optimal ratio.

[0016] The intermediate monoperoxide in step S2 is 1-(tert-butylperoxyisopropyl)-3-(2-hydroxyisopropyl)benzene.

[0017] In step S1, the mass concentration of TBHP tert-butyl hydroperoxide added is 70-80%; in step S2, the mass concentration of trifluoromethanesulfonic acid aqueous solution added is 5%-40%.

[0018] If the concentration of TBHP is too low during the reaction, the amount of TBHP that needs to be added will increase, while a high concentration of TBHP will increase the risk of the reaction. TBHP with a mass concentration of 70-80% is the most readily available and common on the market, so this invention uses TBHP with a mass concentration of 70-80%.

[0019] High concentrations of trifluoromethanesulfonic acid react violently and are highly dangerous; therefore, this invention uses an aqueous solution of trifluoromethanesulfonic acid with a mass concentration of 5%-40%.

[0020] The DC[di-(2-hydroxyisopropyl)benzene] added in step S2 is a mixture of meta and para isomers; the DC[di-(2-hydroxyisopropyl)benzene] is a mixture of meta and para isomers in any proportion.

[0021] In step S2, an alkaline solution is added to control the temperature below 40°C. During the preparation process, the reaction flask is placed in a water bath for heating, so that the reaction temperature of TBHP and DC is controlled at 38-48°C. There is a certain risk when heating TBHP. If an abnormal temperature rise or an abnormally fast heating rate is found (it may be due to abnormal temperature control of the heating equipment, or the decomposition of TBHP itself and exothermic reaction, etc.), a large amount of cold water should be added to the water bath in time, or the reaction flask should be separated from the water bath.

[0022] In step S3, the post-treatment alkaline washing is performed twice.

[0023] The concentration in step S3 is as follows: the bis(tert-butylperoxyisopropyl)benzene condensate is added to a concentration device and concentrated using a reduced pressure desolventizing and nitrogen bubbling process.

[0024] The synthesis reaction process in the method of this invention is as follows:

[0025] TBHP (tert-butyl hydroperoxide) reacts with DC [1,3-di-(2-hydroxyisopropyl)benzene] in 6# solvent oil as solvent and trifluoromethanesulfonic acid as acidic condition to produce BIPB [1,3-di-tert-butyl hydroperoxide isopropyl)benzene]. The reaction equation is as follows:

[0026]

[0027] TBHP (tert-butyl hydroperoxide) reacts with DC [1,4-bis-(2-hydroxyisopropyl)benzene] under acidic conditions provided by trifluoromethanesulfonic acid to generate BIPB [1,4-bis(tert-butyl hydroperoxide isopropyl)benzene]. The reaction equation is as follows:

[0028]

[0029] Existing solvent-free methods for preparing BIPB use a lot of acid, generating large amounts of wastewater containing tert-butyl hydrogen peroxide, BIPB, and various acid decomposition byproducts. This wastewater is neither recyclable nor easy to treat and discharge, which is very detrimental to environmental protection.

[0030] In existing methods for preparing BIPB, sulfuric acid is often used as a catalyst in the solvent preparation process, which generates a large amount of wastewater. The wastewater treatment cost is high and the environmental pollution is significant.

[0031] The difference between this invention and the technology disclosed in CN 119462463 A lies in the use of No. 6 solvent oil as the solvent. No. 6 solvent oil is a commonly used solvent, a mixture of multiple substances, mainly composed of n-hexane and cyclohexane. No. 6 solvent oil has a lower boiling point, faster dehydration speed, easier concentration and recovery, and a more stable reaction rate, which can improve the reaction rate and yield to a certain extent. No. 6 solvent oil does not participate in the reaction; it serves as a carrier for dissolving the products and raw materials. That is, the entire reaction takes place in No. 6 solvent oil without consuming it.

[0032] This invention employs a reduced-pressure process, resulting in a more stable and safer reaction temperature. It also requires less trifluoromethanesulfonic acid, leading to a safer reaction and significantly reduced wastewater treatment costs. For the same 100g of DC, the preparation method in CN 119462463A requires 35-85g of pure trifluoromethanesulfonic acid, while the method in this invention only requires 0.02-2g of pure trifluoromethanesulfonic acid, greatly reducing raw material costs. Furthermore, the preparation method in CN 119462463A requires trifluoromethanesulfonic acid with a concentration of 50%-70%, while the method in this invention only requires trifluoromethanesulfonic acid with a mass concentration of 5%-40%.

[0033] Compared with the prior art, the method for producing bis(tert-butylperoxyisopropyl)benzene of the present invention is applicable to the production of meta- and para-mixed bis(tert-butylperoxyisopropyl)benzene or meta-bis(tert-butylperoxyisopropyl)benzene. The beneficial effects of the present invention are as follows:

[0034] 1. Side reactions are reduced, and the BIPB yield reaches over 96% and the content reaches over 97 wt%;

[0035] 2. The reaction rate has been significantly improved;

[0036] 3. The obtained bis(tert-butylperoxyisopropyl)benzene product has high content / purity and is nearly white in color. It does not require further recrystallization and purification, which shortens the production process and greatly reduces production costs.

[0037] 4. The range of catalyst dosage allows the condensation reaction to proceed more thoroughly, avoiding unexpected situations where the condensation reaction rate slows down or stops midway due to trace amounts of alkaline substances in DC. Detailed Implementation

[0038] The present invention will be further described below with reference to specific embodiments.

[0039] The raw materials used in the examples and comparative examples are all commercially available.

[0040] Unless otherwise specified, the reagents, methods and equipment used in this invention are conventional reagents, methods and equipment in this technical field.

[0041] (1) Add 2000g of 6# solvent oil to the condensation reactor, start stirring, add 800g of 70wt% TBHP to the condensation reactor, control the temperature at 25℃, stir for 20 minutes, let it stand and settle for 20 minutes, and separate the lower aqueous phase (about 60-100g).

[0042] (2) At a reactor temperature of approximately 20°C, add 500g of DC and 25g of a 40wt% trifluoromethanesulfonic acid aqueous solution (DC in any proportion) to the condensation reactor. Adjust the hot water bath temperature to steadily raise the reactor temperature to approximately 40°C. When the temperature reaches approximately 40°C, turn on the condensation vacuum pump and closely monitor the solvent reflux during the condensation reaction. Control the reaction pressure in the condensation reactor at -0.04MPa by adjusting the vacuum regulating valve to ensure normal reflux dehydration occurs at approximately 38°C. During the reaction, the solvent and water are condensed by the condenser and separated by the oil-water separator, with the solvent continuously returning to the condensation reactor. The condensation reaction begins from the point of "solvent reflux." After 2 hours of reaction, sample and analyze the BIPB and monoperoxide content. Samples are then taken every 0.5 to 1 hour thereafter, with the sampling interval determined based on the actual reaction conditions in the later stages of the reaction. The content of the intermediate monoperoxide was detected, and the time to reach the endpoint of the condensation reaction was estimated based on the sampling analysis data. The reaction ended when the content of 1-(tert-butylperoxyisopropyl)-3-(2-hydroxyisopropyl)benzene was 1.0 wt%.

[0043] (3) Bring the pressure in the condensation vessel to atmospheric pressure, add 200g of 30wt% sodium hydroxide aqueous solution to terminate the reaction, control the temperature at 35℃, stir for 20 minutes, then stop stirring and let it stand for 20 minutes. Open the valve between the bottom of the vessel and the residual liquid tank to release the alkali solution into the residual liquid tank. Add 300g of 30wt% sodium hydroxide aqueous solution for a second alkali wash. During the alkali wash, to ensure that the temperature of the subsequent water washing operation is not lower than 25℃, the temperature should be appropriately controlled during the alkali wash process.

[0044] (4) Add 500g of tap water, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Then, put the washing wastewater into the residual liquid tank. Repeat this process for the second water wash until the pH value of the washing water layer is 6.5. The washing is then complete, and a condensate is obtained. The condensate has a neutral pH and is almost colorless.

[0045] (5) Add the bis(tert-butylperoxyisopropyl)benzene condensate into the concentrator and concentrate it by desolvation under reduced pressure. Heat it under normal pressure and slowly raise it to about 55°C. Control the vacuum degree by adjusting the vacuum valve to prevent material overflow. After the concentration is completed, pour the material onto the spreading tray to cool and obtain the finished product.

[0046] Example 2

[0047] (1) Add 1750g of 6# solvent oil to the condensation reactor, start stirring, add 700g of 70wt% TBHP to the condensation reactor, control the temperature at 25℃, stir for 20 minutes, let it stand and settle for 20 minutes, and separate the lower aqueous phase (about 60-100g).

[0048] (2) At a reactor temperature of approximately 20°C, add 500g of DC and 20g of 30wt% trifluoromethanesulfonic acid aqueous solution (DC can be in any proportion) to the condensation reactor. Adjust the hot water bath temperature to steadily raise the reactor temperature to approximately 40°C. When the temperature reaches approximately 40°C, turn on the condensation vacuum pump and closely monitor the solvent reflux during the condensation reaction. Control the reaction pressure in the condensation reactor at -0.05MPa by adjusting the vacuum regulating valve to ensure normal reflux dehydration occurs when the condensation reaction temperature is maintained between 38 and 48°C. During the reaction, the solvent and water are condensed by the condenser and separated by the oil-water separator, with the solvent continuously returning to the condensation reactor. The condensation reaction begins from the point of "solvent reflux." After 2 hours of reaction, sample and analyze the BIPB and monoperoxide content. Samples are then taken every 0.5 to 1 hour thereafter, with the sampling interval determined based on the actual reaction conditions in the later stages of the reaction. The content of the intermediate monoperoxide was detected, and the time to reach the endpoint of the condensation reaction was estimated based on the sampling analysis data. The reaction ended when the content of 1-(tert-butylperoxyisopropyl)-3-(2-hydroxyisopropyl)benzene was 1.0 wt%.

[0049] (3) Bring the pressure in the condensation vessel to atmospheric pressure, add 300g of 20wt% sodium hydroxide aqueous solution to terminate the reaction, control the temperature at 35℃, stir for 20 minutes, then stop stirring and let it stand for 20 minutes. Open the valve between the bottom of the vessel and the residual liquid tank to release the alkali solution into the residual liquid tank. Add 350g of 20wt% sodium hydroxide aqueous solution for a second alkali wash. During the alkali wash, to ensure that the temperature of the subsequent water washing operation is not lower than 25℃, the temperature should be appropriately controlled during the alkali wash process.

[0050] (4) Add 400g of tap water, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Then, put the washing wastewater into the residual liquid tank. Repeat this process for the second water wash until the pH value of the washing water layer is 6.8. The washing is then complete, and a condensate is obtained. The condensate has a neutral pH and is almost colorless.

[0051] (5) Add the bis(tert-butylperoxyisopropyl)benzene condensate into the concentrator and concentrate it by desolvation under reduced pressure. Heat it under normal pressure and slowly raise it to about 55°C. Control the vacuum degree by adjusting the vacuum valve to prevent material overflow. After the concentration is completed, pour the material onto the spreading tray to cool and obtain the finished product.

[0052] Example 3

[0053] (1) Add 1500g of 6# solvent oil to the condensation reactor, start stirring, add 700g of 75wt%TBHP to the condensation reactor, control the temperature at 25℃, stir for 20 minutes, let it stand and settle for 20 minutes, and separate the lower aqueous phase (about 60-100g).

[0054] (2) At a reactor temperature of approximately 20°C, add 500g of DC and 10g of a 20wt% trifluoromethanesulfonic acid aqueous solution (DC can be in any proportion) to the condensation reactor. Adjust the hot water bath temperature to steadily raise the reactor temperature to approximately 40°C. When the temperature reaches approximately 40°C, turn on the condensation vacuum pump and closely monitor the solvent reflux during the condensation reaction. Control the reaction pressure in the condensation reactor at -0.06MPa by adjusting the vacuum regulating valve to ensure normal reflux dehydration occurs when the condensation reaction temperature is maintained between 38 and 48°C. During the reaction, the solvent and water are condensed by the condenser and separated by the oil-water separator, with the solvent continuously returning to the condensation reactor. The condensation reaction begins from the point of "solvent reflux." After 2 hours of reaction, sample and analyze the BIPB and monoperoxide content. Samples are then taken every 0.5 to 1 hour thereafter, with the sampling interval determined based on the actual reaction conditions in the later stages of the reaction. The content of the intermediate monoperoxide was detected, and the time to reach the endpoint of the condensation reaction was estimated based on the sampling analysis data. The reaction ended when the content of 1-(tert-butylperoxyisopropyl)-3-(2-hydroxyisopropyl)benzene was 1.0 wt%.

[0055] (3) Bring the pressure in the condensation vessel to atmospheric pressure, add 300g of 15wt% sodium hydroxide aqueous solution to terminate the reaction, control the temperature at 35℃, stir for 20 minutes, then stop stirring and let it stand for 20 minutes. Open the valve between the bottom of the vessel and the residual liquid tank to release the alkali solution into the residual liquid tank. Add 350g of 15wt% sodium hydroxide aqueous solution for a second alkali wash. During the alkali wash, to ensure that the temperature of the following water washing operation is not lower than 25℃, the temperature should be appropriately controlled during the alkali wash process.

[0056] (4) Add 350g of tap water, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Then, put the washing wastewater into the residual liquid tank. Repeat this process for the second water wash until the pH value of the washing water layer is 7. The washing is then complete, and a condensate is obtained. The condensate has a neutral pH and is almost colorless.

[0057] (5) Add the bis(tert-butylperoxyisopropyl)benzene condensate into the concentrator and concentrate it by desolvation under reduced pressure. Heat it under normal pressure and slowly raise it to about 55°C. Control the vacuum degree by adjusting the vacuum valve to prevent material overflow. After the concentration is completed, pour the material onto the spreading tray to cool and obtain the finished product.

[0058] Example 4

[0059] (1) Add 1250g of 6# solvent oil to the condensation reactor, start stirring, add 650g of 80wt% TBHP to the condensation reactor, control the temperature at 25℃, stir for 20 minutes, let it stand and settle for 20 minutes, and separate the lower aqueous phase (about 60-100g).

[0060] (2) At a reactor temperature of approximately 20°C, add 500g of DC and 5g of 10wt% trifluoromethanesulfonic acid aqueous solution (DC can be in any proportion) to the condensation reactor. Adjust the hot water bath temperature to steadily raise the reactor temperature to approximately 40°C. When the temperature reaches approximately 40°C, turn on the condensation vacuum pump and closely monitor the solvent reflux during the condensation reaction. Control the reaction pressure in the condensation reactor at -0.07MPa by adjusting the vacuum regulating valve to ensure normal reflux dehydration occurs when the condensation reaction temperature is maintained between 38 and 48°C. During the reaction, the solvent and water are condensed by the condenser and separated by the oil-water separator, with the solvent continuously returning to the condensation reactor. The condensation reaction begins from the point of solvent reflux. After 2 hours of reaction, sample and analyze the BIPB and monoperoxide content. Samples are then taken every 0.5 to 1 hour thereafter, with the sampling interval determined based on the actual reaction conditions in the later stages of the reaction. The content of the intermediate monoperoxide was detected, and the time to reach the endpoint of the condensation reaction was estimated based on the sampling analysis data. The reaction ended when the content of 1-(tert-butylperoxyisopropyl)-3-(2-hydroxyisopropyl)benzene was 1.0 wt%.

[0061] (3) Bring the pressure in the condensation vessel to atmospheric pressure, add 400g of 10wt% sodium hydroxide aqueous solution to terminate the reaction, control the temperature at 35℃, stir for 20 minutes, then stop stirring and let it stand for 20 minutes. Open the valve between the bottom of the vessel and the residual liquid tank to release the alkali solution into the residual liquid tank. Add 450g of 10wt% sodium hydroxide aqueous solution for the second alkali wash. During the alkali wash, to ensure that the temperature of the following water washing operation is not lower than 25℃, the temperature should be appropriately controlled during the alkali wash process.

[0062] (4) Add 300g of tap water, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Then, put the washing wastewater into the residual liquid tank. Repeat this process for the second water wash until the pH value of the washing water layer is 7.3. The washing is then complete, and a condensate is obtained. The condensate has a neutral pH and is almost colorless.

[0063] (5) Add the bis(tert-butylperoxyisopropyl)benzene condensate into the concentrator and concentrate it by desolvation under reduced pressure. Heat it under normal pressure and slowly raise it to about 55°C. Control the vacuum degree by adjusting the vacuum valve to prevent material overflow. After the concentration is completed, pour the material onto the spreading tray to cool and obtain the finished product.

[0064] Example 5

[0065] (1) Add 1000g of 6# solvent oil to the condensation reactor, start stirring, add 600g of 80wt% TBHP to the condensation reactor, control the temperature at 25℃, stir for 20 minutes, let it stand and settle for 20 minutes, and separate the lower aqueous phase (about 60-100g).

[0066] (2) At a reactor temperature of approximately 20°C, add 500g of DC and 2g of 5wt% trifluoromethanesulfonic acid aqueous solution to the condensation reactor. The DC content can be any ratio. By adjusting the hot water bath temperature, the reactor temperature is steadily raised to approximately 40°C. When the temperature reaches approximately 40°C, turn on the condensation vacuum pump and closely monitor the solvent reflux during the condensation reaction. Control the reaction pressure in the condensation reactor at -0.08MPa by adjusting the vacuum regulating valve to ensure normal reflux dehydration occurs when the condensation reaction temperature is maintained at approximately 38-48°C. During the reaction, the solvent and water are condensed by the condenser and then separated by the oil-water separator, with the solvent continuously returning to the condensation reactor. The condensation reaction begins from the point of "solvent reflux". After 2 hours of reaction, take samples to analyze the BIPB and monoperoxide content. Samples are then taken every 0.5 to 1 hour thereafter. The sampling interval is determined based on the actual reaction conditions in the later stages of the reaction. The content of the intermediate monoperoxide was detected, and the time to reach the endpoint of the condensation reaction was estimated based on the sampling analysis data. The reaction ended when the content of 1-(tert-butylperoxyisopropyl)-3-(2-hydroxyisopropyl)benzene was 1.0 wt%.

[0067] (3) Bring the pressure in the condensation vessel to atmospheric pressure, add 400g of 33wt% sodium hydroxide aqueous solution to terminate the reaction, control the temperature at 35℃, stir for 20 minutes, then stop stirring and let it stand for 20 minutes. Open the valve between the bottom of the vessel and the residual liquid tank to release the alkali solution into the residual liquid tank. Add 600g of 3wt% sodium hydroxide aqueous solution for a second alkali wash. During the alkali wash, to ensure that the temperature of the following water washing operation is not lower than 25℃, the temperature should be appropriately controlled during the alkali wash process.

[0068] (4) Add 250g of tap water, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Then, put the washing wastewater into the residual liquid tank. Repeat this process for the second water wash until the pH value of the washing water layer is 7.5. The washing is then complete, and a condensate is obtained. The condensate has a neutral pH and is almost colorless.

[0069] (5) Add the bis(tert-butylperoxyisopropyl)benzene condensate into the concentrator and concentrate it by desolvation under reduced pressure. Heat it under normal pressure and slowly raise it to about 55°C. Control the vacuum degree by adjusting the vacuum valve to prevent material overflow. After the concentration is completed, pour the material onto the spreading tray to cool and obtain the finished product.

[0070] Comparative Example 1 (Preparation method disclosed in CN106588735A, US318750412):

[0071] (1) Add 1800g of n-hexane to the condensation reactor, start stirring, add 650g of 80wt% TBHP aqueous solution to the condensation reactor, control the temperature at 25℃, stir for 20 minutes, let it stand and settle for 20 minutes, and separate the lower aqueous phase (about 60-100g).

[0072] (2) Adjust the temperature of the vessel to 0-10℃, introduce carbon dioxide, and add 500g DC and 2525g 50wt% sulfuric acid aqueous solution to the condensation reaction vessel. The DC can be in any proportion. Maintain the temperature of the vessel at 0-10℃ for about 1 hour, and then quickly add 800g of 85℃-95℃ hot water.

[0073] (3) The upper organic phase is neutralized with 4% sodium hydroxide solution, and then 800g of tap water is added. After stirring for 20 minutes, stirring is stopped, and the mixture is allowed to stand for 20 minutes. The washing wastewater is then placed in the residual liquid tank. The second washing is performed in this manner until the pH of the washing water layer is 6.5-7.5. The washing is then completed, and a condensate is obtained. The condensate has a neutral pH and is almost colorless.

[0074] (4) Add the bis(tert-butylperoxyisopropyl)benzene condensate into the concentrator and concentrate it by desolvation under reduced pressure. Heat it under normal pressure and slowly raise it to about 55°C. Control the vacuum degree by adjusting the vacuum valve to prevent material overflow. After the concentration is completed, pour the material onto the spreading tray to cool and obtain the finished product.

[0075] Comparative Example 2 (Preparation method CN102796035A):

[0076] (1) Add 1400g of 6# oil to the condensation reactor, start stirring, add 650g of 80wt% TBHP aqueous solution to the condensation reactor, control the temperature at 25℃, stir for 20 minutes, let it stand and settle for 20 minutes, and separate the lower aqueous phase (about 60-100g).

[0077] (2) At a reactor temperature of approximately 20°C, add 500g of DC and 12g of 50wt% perchloric acid aqueous solution (DC can be in any proportion) to the condensation reactor. Adjust the hot water bath temperature to steadily raise the reactor temperature to approximately 40°C. When the temperature reaches approximately 40°C, turn on the condensation vacuum pump and closely monitor the solvent reflux during the condensation reaction. Control the reaction pressure in the condensation reactor between -0.04 and -0.08 MPa by adjusting the vacuum regulating valve to ensure normal reflux dehydration occurs when the condensation reaction temperature is maintained between 38 and 48°C. During the reaction, the solvent and water are condensed by the condenser and separated by the oil-water separator, with the solvent continuously returning to the condensation reactor. The condensation reaction begins from the point of "solvent reflux." After 2 hours of reaction, sample and analyze the BIPB and monoperoxide content. Samples are then taken every 0.5 to 1 hour thereafter, with the sampling interval determined based on the actual reaction conditions in the later stages of the reaction. The content of the intermediate monoperoxide was detected, and the time to reach the endpoint of the condensation reaction was estimated based on the sampling analysis data. The reaction ended when the content of 1-(tert-butylperoxyisopropyl)-3-(2-hydroxyisopropyl)benzene was 1.0 wt%, and the pressure in the condensation vessel was reduced to atmospheric pressure. 100 g of water was added to the vessel to terminate the reaction, and the temperature was lowered to 35–40 °C.

[0078] (3) Add 300g of 15wt% sodium hydroxide aqueous solution for alkaline washing. Stir for 20 minutes, then stop stirring and let stand for 20 minutes. Open the valve between the bottom of the vessel and the residual liquid tank to release the alkaline solution into the residual liquid tank. Add 400g of 15wt% sodium hydroxide aqueous solution for a second alkaline wash. To ensure that the temperature of the following water washing operation is not lower than 25℃, the temperature should be appropriately controlled during the alkaline washing process.

[0079] (4) Add 400g of tap water, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Then, put the washing wastewater into the residual liquid tank. Repeat this process for the second water wash until the pH of the washing water layer is 6.5-7.5. The washing is then complete, and a condensate is obtained. The condensate has a neutral pH and is almost colorless.

[0080] (5) Add the bis(tert-butylperoxyisopropyl)benzene condensate into the concentrator and concentrate it by desolvation under reduced pressure. Heat it under normal pressure and slowly raise it to about 55°C. Control the vacuum degree by adjusting the vacuum valve to prevent material overflow. After the concentration is completed, pour the material onto the spreading tray to cool and obtain the finished product.

[0081] Comparative Example 3 (Preparation method of CN119462463A):

[0082] (1) Raw material feeding: Add 650g of 80wt% TBHP to the condensation reactor at 35℃, turn on the mechanical stirrer, control the speed at 200rpm, pay attention to the temperature change, slowly add 500g of DC, stabilize the temperature in the reaction flask at 40℃ to allow TBHP and DC to react fully; cool down the temperature in the reaction flask, adjust the stirring speed to 280rpm, slowly add 240g of 45wt% trifluoromethanesulfonic acid, and control the dropping temperature at 42℃;

[0083] (2) Condensation reaction: After all the trifluoromethanesulfonic acid has been added, the temperature is raised to 53°C and kept at that temperature for 4 hours. Then, 100g of water is added to terminate the reaction. After stirring and controlling the temperature, the mixture is allowed to stand.

[0084] (3) Post-treatment alkaline washing: Add 700g of 30wt% sodium hydroxide aqueous solution for alkaline washing, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Open the valve between the bottom of the vessel and the residual liquid tank to release the alkaline solution into the residual liquid tank. Add 700g of 30wt% sodium hydroxide aqueous solution for a second alkaline washing. During alkaline washing, ensure the temperature is kept above 48℃.

[0085] (4) Add 400g of tap water, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Then put the washing wastewater into the residual liquid tank and perform the second water wash. When washing, keep the temperature above 48℃. After the water wash is completed, discharge the reaction wastewater into the wastewater collection tank in layers, retain the upper organic phase, pour the organic phase onto the spreading tray to cool and obtain the finished product.

[0086] Comparative Example 4 (Preparation method of CN119462463A)

[0087] (1) Raw material feeding: Add 650g of 80wt% TBHP to the condensation reactor at 35℃, turn on the mechanical stirrer, control the speed at 200rpm, pay attention to the temperature change, slowly add 500g of DC, stabilize the temperature in the reaction flask at 40℃ to allow TBHP and DC to react fully; cool down the temperature in the reaction flask, adjust the stirring speed to 280rpm, slowly add 240g of 70wt% trifluoromethanesulfonic acid, and control the dropping temperature at 42℃;

[0088] (2) Condensation reaction: After all the trifluoromethanesulfonic acid has been added, the temperature is raised to 53°C and kept at that temperature for 3 hours. Then, 100g of water is added to terminate the reaction. After stirring and controlling the temperature, the mixture is allowed to stand.

[0089] (3) Post-treatment alkaline washing: Add 700g of 30wt% sodium hydroxide aqueous solution for alkaline washing, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Open the valve between the bottom of the vessel and the residual liquid tank to release the alkaline solution into the residual liquid tank. Add 700g of 30wt% sodium hydroxide aqueous solution for a second alkaline washing. During alkaline washing, ensure the temperature is kept above 48℃.

[0090] (4) Add 400g of tap water, stir for 20 minutes, then stop stirring and let stand for 20 minutes. Then put the washing wastewater into the residual liquid tank and perform the second water wash. When washing, keep the temperature above 48℃. After the water wash is completed, discharge the reaction wastewater into the wastewater collection tank in layers, retain the upper organic phase, pour the organic phase onto the spreading tray to cool and obtain the finished product.

[0091] The performance of the finished products obtained from the above embodiments and comparative examples was tested as follows:

[0092] 1. Weigh the finished products obtained from Examples 1-5 and Comparative Examples 1-4, and calculate the yield;

[0093] 2. Analyze the finished products obtained in Examples 1-5 and Comparative Examples 1-4 by liquid chromatography, record the content, detect the whiteness with a whiteness meter, and test the melting point with a melting point apparatus.

[0094] The BIPB test results for each embodiment and comparative example are as follows:

[0095]

[0096] In the preparation processes of Comparative Examples 1 and 2, sulfuric acid and sodium perchlorate were used as catalysts, while in the preparation processes of Comparative Examples 3 and 4, trifluoromethanesulfonic acid was used as a catalyst. Examples 1-5 and Comparative Examples 1-2 demonstrate that, in the presence of a solvent, 5%-40% by mass of trifluoromethanesulfonic acid and 70%-80% by mass of TBHP can prepare qualified BIPB under certain ratios. Furthermore, using a small amount of trifluoromethanesulfonic acid can make the reaction rate faster than using perchloric acid as a catalyst, and the quality of the obtained BIPB is also better.

[0097] Comparative Examples 3 and 4 used a solvent-free process to prepare BIPB. BIPB prepared with trifluoromethanesulfonic acid at a concentration below 50% by mass was substandard, requiring an increased amount of trifluoromethanesulfonic acid and a longer reaction time. The quality of the final BIPB could not be guaranteed. Using trifluoromethanesulfonic acid at a concentration of 70% by mass significantly increased production safety risks and made wastewater treatment more difficult. However, the method of this invention uses No. 6 solvent oil as the solvent, requiring only a small amount of low-concentration trifluoromethanesulfonic acid, reducing production costs and safety risks, and greatly reducing subsequent wastewater pressure.

[0098] As can be seen from the above, using trifluoromethanesulfonic acid as a catalyst results in a shorter reaction time, requires less acid catalyst, and produces BIPB with higher content, whiter color, and better quality.

[0099] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst, characterized in that, Includes the following steps: Step S1, Raw material feeding: Add No. 6 solvent oil to the reactor, stir, add TBHP tert-butyl hydrogen peroxide, extract fully, and let stand to separate layers and remove water; Step S2, condensation reaction: DC [di-(2-hydroxyisopropyl)benzene] and trifluoromethanesulfonic acid aqueous solution are added to the dehydrated reaction solution. The vacuum pump is turned on to adjust the pressure inside the reactor to negative pressure and carry out the condensation reaction. During the condensation reaction, the gas phase is condensed and separated to obtain No. 6 solvent oil, which is refluxed back to the reactor. The content of intermediate monoperoxide is sampled and analyzed. When the content of intermediate monoperoxide is ≦1.5wt%, alkali solution is added to terminate the reaction. The mixture is then stirred and allowed to stand under controlled temperature. Step S3, post-treatment alkaline washing: The above-mentioned static reaction solution is separated into liquids, and the upper organic phase is retained. The organic phase is then subjected to alkaline washing and water washing in sequence. The reaction wastewater is discharged to the wastewater treatment system in layers, and the upper organic phase is retained. The organic phase is concentrated under reduced pressure, cooled and solidified, and then crushed to obtain the finished product.

2. The method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst according to claim 1, characterized in that, In step S1, the stirring speed is 200 rpm and the stirring temperature is controlled at 20-30℃; in step S2, DC [di-(2-hydroxyisopropyl)benzene] is added followed by trifluoromethanesulfonic acid aqueous solution; the condensation reaction temperature is 38-48℃; the vacuum regulating valve controls the reaction pressure of the condensation vessel at -(0.04-0.08) MPa; the alkaline solution is a 3%-30% sodium hydroxide solution.

3. The method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst according to claim 1, characterized in that, The weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to No. 6 solvent oil is 100:200-400; the weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to TBHP (tert-butyl hydroperoxide) is 100:120-160; the weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to trifluoromethanesulfonic acid aqueous solution is 100:0.4-5; the weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to alkaline solution is 100:100-200; and the weight ratio of DC[di-(2-hydroxyisopropyl)benzene] to washing water is 100:100-200.

4. The method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst according to claim 1, characterized in that, The intermediate monoperoxide in step S2 is 1-(tert-butylperoxyisopropyl)-3-(2-hydroxyisopropyl)benzene.

5. The method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst according to claim 1, characterized in that, In step S1, the mass concentration of TBHP tert-butyl hydroperoxide added is 70-80%; in step S2, the mass concentration of trifluoromethanesulfonic acid aqueous solution added is 5%-40%.

6. The method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst according to claim 1, characterized in that, The DC [di-(2-hydroxyisopropyl)benzene] added in step S2 is a mixture of meta and para isomers.

7. The method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst according to claim 6, characterized in that, The DC [di-(2-hydroxyisopropyl)benzene] is a mixture of meta and para isomers in any proportion.

8. The method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst according to claim 1, characterized in that, The post-treatment alkaline washing in S3 is performed twice.

9. The method for synthesizing BIPB using trifluoromethanesulfonic acid as a catalyst according to claim 1, characterized in that, The concentration in step S3 is as follows: the bis(tert-butylperoxyisopropyl)benzene condensate is added to a concentration device and concentrated using a depressurized solvent removal or nitrogen bubbling process.

Images