Synthesis method of di (2-ethylhexyl) peroxydicarbonate and equipment for implementing synthesis method

Abstract

The invention provides a synthetic method of di (2-ethylhexyl) peroxydicarbonate and equipment for implementing the synthetic method. The synthesis method comprises the following steps that an alkaline solution, a hydrogen peroxide solution and a chloroformic acid-2-ethylhexyl ester solution are subjected to a primary reaction through a microreactor, a first oil-water mixed solution is obtained, and before the primary reaction, the alkaline solution, the hydrogen peroxide solution and the chloroformic acid-2-ethylhexyl ester solution are mixed through a micromixer; conveying the first oil-water mixed solution into an aging reaction kettle for continuous reaction to obtain a second oil-water mixed solution; performing liquid separation treatment on the second oil-water mixed liquid to obtain an oil phase; and carrying out post-treatment on the oil phase to obtain the di (2-ethylhexyl) peroxydicarbonate. The active oxygen content of the di (2-ethylhexyl) peroxydicarbonate obtained by the synthesis method disclosed by the invention reaches 4.61%, and the chlorine content is lower than 0.05%.

Description

Technical Field

[0001] The invention relates to a method and equipment for synthesizing di(2-ethylhexyl) peroxydicarbonate, in particular to a method for synthesizing di(2-ethylhexyl) peroxydicarbonate based on a continuous flow reactor and equipment for implementing the method, belonging to the technical field of fine chemical synthesis. Background Art

[0002] Organic peroxides are a class of organic compounds characterized by peroxide bonds (-OO-). They have been widely used in the chemical industry since the 1950s, mainly as initiators for polymer production and additives for polymer processing and modification. They include alkyl hydroperoxides, dialkyl peroxides, ketone peroxides, ester peroxides, diacyl peroxides and peroxydicarbonates, etc. With the continuous increase in global demand for polymers, the application areas of organic peroxides are constantly expanding, and their development prospects are very broad.

[0003] At present, most of the enterprises in the organic peroxide industry are small in scale and have a single product variety, which presents a small and scattered situation overall. Therefore, it is not difficult to see that organic peroxides cannot meet the needs of the domestic market in terms of variety or production capacity.

[0004] Di(2-ethylhexyl) peroxydicarbonate, referred to as EHP, is a typical di(2-ethylhexyl) peroxydicarbonate, belongs to the low temperature organic peroxide category, and is liquid at normal temperature and pressure. It is often used as the initiator for producing acrylic resin, low density polyethylene, polyvinyl chloride in industry, and has the excellent characteristics such as high initiation activity, uniform reaction speed, environmental protection, and high quality of obtained products in the production of polyvinyl chloride. From the production technology point of view, at present, di(2-ethylhexyl) peroxydicarbonate mainly adopts the semi-batch process synthesis based on stirred tank reactor (for example, referring to reference 1, reference 2 and reference 3), namely, in strong alkaline solution, the method for successively dripping hydrogen peroxide and 2-ethylhexyl chloroformate is synthesized, and is accompanied by the processes such as subsequent water separation, washing, drying, formulation, there are the problems such as high risk of reaction heat, long feeding time, and difficult control of process, and it is a typical dangerous process. The reaction process also inevitably produces 2-ethylhexyl chloroformate hydrolysis product, affects product quality, and increases post-processing difficulty. Therefore, it is an inevitable trend to develop efficient, safe and continuous synthesis processes and equipment for di(2-ethylhexyl) peroxydicarbonate.

[0005] Since it was proposed in 1990, microchemical technology has become an innovative technology in the chemical industry due to its high efficiency and safety, and was selected as the "2019 Global Engineering Development Frontier". This technology can enhance the safety of chemical processes, promote process intensification and miniaturization of chemical systems, improve the efficiency of energy and resource utilization, achieve the goal of energy conservation and consumption reduction, and has a relatively broad application prospect. Compared with traditional kettle reactors, the heat transfer coefficient of microreactors can be increased from 2kW / (m 2 ·K) increased to 20kW / (m 2 ·K). Therefore, for fast reactions with high exothermicity, such as the synthesis of di(2-ethylhexyl) peroxydicarbonate, the microreactor can quickly remove the heat generated by the reaction, effectively avoid local overheating, reduce the occurrence of side reactions, and prevent the temperature runaway phenomenon caused by heat accumulation, thereby reducing the risk of reaction runaway.

[0006] At present, there are reports on the preparation of di(2-ethylhexyl) peroxydicarbonate using microchemical technology. For example:

[0007] Reference document 4 discloses a method for preparing di(2-ethylhexyl)peroxydicarbonate by continuous flow, including preparing alkaline aqueous solution, reacting alkaline aqueous solution and hydrogen peroxide in a reactor, adding chloroformic acid-2-ethylhexyl ester solution to react with the product of alkaline aqueous solution and hydrogen peroxide, and the product is further fully reacted through a delay line to obtain a product. However, the method is a secondary mixed process, and solids can be generated after mixing with a hydrogen peroxide solution according to the concentration of alkali solution, which can cause the blocking of a microreactor. In addition, the chloroformic acid-2-ethylhexyl ester used is not miscible with water, and the chloroformic acid-2-ethylhexyl ester reacts with water, and the product is also difficult to miscible with water. In addition, its entire reaction is substantially completed in the 2# reactor, and then enters the delay line to complete the full reaction, but a very long pipeline is needed in this way, and the overly long pipeline causes excessive pressure drop and increased energy consumption, which is very uneconomical.

[0008] Reference 5 discloses a method for continuously preparing di(2-ethylhexyl) peroxydicarbonate in one step using a micro-packed bed reactor device, which comprises the following steps: mixing an aqueous hydrogen peroxide solution and a phase transfer catalyst to prepare a solution 1; pumping solution 1, an aqueous sodium hydroxide solution and a 2-ethylhexyl chloroformate solution into a micro-mixer for premixing and then entering a micro-packed bed reactor for reaction to obtain a reaction solution 2; the reaction solution 2 is passed into a separation tank for static stratification to obtain an upper oil phase to obtain di(2-ethylhexyl) peroxydicarbonate. Although the method uses a phase transfer catalyst to improve the mass transfer performance of the oil-water two-phase, the subsequent purification cost and operational complexity are greatly increased. In addition, due to the use of a phase transfer catalyst (such as tetrabutylammonium chloride), the chloride ion content of the finished product of di(2-ethylhexyl) peroxydicarbonate is too high, which reduces the product quality.

[0009] References:

[0010] Reference 1: CN102443081A

[0011] Reference 2: CN102584663A

[0012] Reference 3: CN102659960B

[0013] Reference 4: CN104370789A

[0014] Reference 5: CN117924134A Summary of the invention

[0015] Problem that the invention aims to solve

[0016] The synthesis reaction of di(2-ethylhexyl) peroxydicarbonate is a highly exothermic reaction. Generally speaking, in industrial production (i.e., kettle process), in order to ensure safe production, the reaction temperature is generally lowered while the dripping rate of hydrogen peroxide and sodium hydroxide is slowed down to prevent the occurrence of local hot spots. However, the lower the temperature, the longer the reaction time required, which greatly reduces the production efficiency.

[0017] Reference 5 is open to react in microreactor, greatly reduces reaction time compared with kettle process, and safety factor is higher. However, the inventor finds that the oil-water mixture obtained by making chloroformic acid-2-ethylhexyl ester solution and alkaline hydrogen peroxide preliminary reaction in microreactor is a heterogeneous state, for heterogeneous reaction, there is a problem of slow reaction late rate and insufficient reaction, and, in order to obtain high-quality peroxydicarbonate di(2-ethylhexyl) ester product, then need the conversion rate of chloroformic acid-2-ethylhexyl ester to be very close to 100%, the inventor finds in research, the reaction early reactant concentration is higher, it is the faster reaction of intrinsic reaction kinetics, but mass transfer resistance is large, the apparent chemical reaction rate is almost completely subject to the restriction of mass transfer resistance, now, after utilizing microreactor to strengthen mass transfer, reaction can be accelerated, while strengthening heat transfer to ensure efficient reaction, there is safety. However, as the reaction proceeds, the concentration of reactants is very low in the later stage of the reaction, the intrinsic reaction rate is slow, the apparent chemical reaction rate is no longer limited by the mass transfer resistance, and the heat release rate accompanying the reaction is also slow, and the thermal risk of the reaction is low. For the later stage of this heterogeneous reaction, the advantages of the microreactor are not obvious. At this time, if the microreactor is continued to be used for subsequent delayed reactions, the energy consumption and equipment costs will be greatly increased.

[0018] In view of the problems existing in the prior art, such as high thermal risk, high energy consumption, low production efficiency, low product quality, etc., the present invention first provides a method for synthesizing di(2-ethylhexyl) peroxydicarbonate. The synthesis method is a continuous synthesis process combining a microreactor and a reactor to achieve safe and efficient conversion of raw materials into commercial products.

[0019] Furthermore, the synthesis method of di(2-ethylhexyl) peroxydicarbonate of the present invention also solves the problems of large liquid holding capacity, poor heat exchange capacity and poor liquid-liquid dispersion effect of existing production processes and reaction equipment at home and abroad, and at the same time improves the efficiency and safety level of the peroxidation process.

[0020] Furthermore, the present invention also provides a device for implementing the synthesis method of di(2-ethylhexyl) peroxydicarbonate. The device is simple and can ensure that the treatment method is carried out efficiently and orderly. The thermal risk of using the device is low and the production efficiency is high.

[0021] Solutions for solving problems

[0022] The invention is based on the characteristics of efficient micro-scale mixing, good mass transfer and heat transfer performance and intrinsic safety of microreactor technology. While ensuring the high selectivity of di(2-ethylhexyl) peroxydicarbonate, the conversion rate of 2-ethylhexyl chloroformate can be significantly improved, and a reaction kettle is used for delayed reaction, which effectively solves the problems of large mass transfer resistance and slow reaction speed in the late stage, greatly reduces reaction energy consumption and equipment costs, and has simple operation process, strong controllability, and can realize continuous production.

[0023] Specifically, the present invention can solve the above technical problems by implementing the following technical solutions:

[0024] [1]. The present invention provides a method for synthesizing di(2-ethylhexyl) peroxydicarbonate, which comprises the following steps:

[0025] The alkaline solution, the hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution are subjected to a preliminary reaction via a microreactor to obtain a first oil-water mixture, wherein before the preliminary reaction, the alkaline solution, the hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution have been mixed via a micromixer;

[0026] The first oil-water mixture is transported to an aging reactor to continue the reaction to obtain a second oil-water mixture;

[0027] performing liquid separation treatment on the second oil-water mixture and obtaining an oil phase;

[0028] The oil phase is post-treated to obtain di(2-ethylhexyl) peroxydicarbonate.

[0029] [2] The synthesis method according to [1], wherein

[0030] In the alkaline solution, the concentration of the alkaline substance is 1 to 30 wt %;

[0031] In the hydrogen peroxide solution, the concentration of hydrogen peroxide is 20 to 60 wt %;

[0032] In the 2-ethylhexyl chloroformate solution, the concentration of 2-ethylhexyl chloroformate is 50-100 wt %.

[0033] [3]. The synthesis method according to [2], wherein

[0034] The molar ratio of the alkaline substance to the 2-ethylhexyl chloroformate is (1-2):1;

[0035] The molar ratio of the hydrogen peroxide to the 2-ethylhexyl chloroformate is (0.5-1):1.

[0036] [4] The synthesis method according to any one of [1] to [3], wherein the micromixer is a microchannel mixer, a membrane dispersion mixer or a microsieve mixer; and the microreactor is a coil microreactor, a micropacked bed reactor or a microchannel reactor.

[0037] [5] The synthesis method according to any one of [1] to [4], wherein the micromixer comprises a first micromixer and a second micromixer, and the microreactor comprises a first microreactor and a second microreactor; wherein,

[0038] The alkaline solution and the hydrogen peroxide solution are mixed in the first micro-mixer and then enter the first micro-reactor for reaction to obtain an alkaline hydrogen peroxide solution;

[0039] The alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution are liquid-liquid dispersed in the second micromixer and then enter the second microreactor for preliminary reaction to obtain a first oil-water mixed liquid.

[0040] [6]. The synthesis method according to [5], wherein

[0041] The temperature in the first micro mixer is 0 to 45° C., and the mixing time is 0.1 to 10 seconds;

[0042] The temperature in the first microreactor is 0 to 45°C, and the residence time is 0.01 to 5 min;

[0043] The temperature in the second micro mixer is 0 to 50° C., and the mixing time is 0.1 to 10 seconds;

[0044] The temperature in the second microreactor is 0 to 50°C, and the residence time is 0.1 to 20 min;

[0045] The temperature in the aging reactor is 0-45° C., and the residence time is 10-180 min.

[0046] [7] The synthesis method according to any one of [1] to [6], wherein the post-treatment comprises one or more of washing, drying and microporous membrane filtration.

[0047] [8]. The synthesis method according to [7], wherein

[0048] The washing is performed by using a washing liquid; the washing liquid is an inorganic salt aqueous solution with a concentration of 0 to 10 wt%; and / or,

[0049] The drying is performed by using a desiccant and / or a dry gas; the desiccant includes one or more of anhydrous sodium sulfate, anhydrous magnesium sulfate and anhydrous calcium chloride; the dry gas is dry air or dry nitrogen; and / or,

[0050] The filtration is performed using a microporous filter membrane with an average pore size of 0.01 to 10 μm; the microporous filter membrane is made of an oleophilic and hydrophobic material.

[0051] [9]. The synthesis method according to any one of [1] to [8], wherein the synthesis method further comprises the step of diluting the di(2-ethylhexyl) peroxydicarbonate with a diluent; preferably, the diluent comprises an oily solvent or an aqueous dispersion.

[0052]

[10] . Furthermore, the present invention also provides a device for implementing the synthesis method described in any one of [1] to [9] above, wherein the device comprises a micro mixer, a micro reactor, an aging reactor and a liquid separator connected in sequence;

[0053] The micromixer includes a first micromixer and a second micromixer, and the microreactor includes a first microreactor and a second microreactor; wherein the first micromixer, the first microreactor, the second micromixer and the second microreactor are connected in sequence;

[0054] Preferably, the liquid separator is further connected to one or more of a washing liquid separator, a dryer, a microporous membrane filter and a mixing tank.

[0055] Effects of the Invention

[0056] By implementing the above technical solution, the present invention can achieve the following technical effects:

[0057] Compared with traditional kettle reactors, the present invention prepares di(2-ethylhexyl) peroxydicarbonate through a continuous process with a micromixer and a microreactor as the core, which can control local heat accumulation by rapid heat transfer, reduce the risk of combustion and explosion for thermally unstable organic peroxides, and at the same time increase the contact area between the oil and water phases, thereby greatly improving production efficiency by increasing the reaction rate.

[0058] The invention uses a synthesis process combining a microreactor and a reaction kettle to prepare di(2-ethylhexyl) peroxydicarbonate, which greatly reduces the feeding time and the reaction energy consumption and improves the conversion efficiency from the raw material to the commercial product of di(2-ethylhexyl) peroxydicarbonate.

[0059] Furthermore, the di(2-ethylhexyl) peroxydicarbonate product prepared by the synthesis method of the present invention has an active oxygen content (up to 4.61%) and other quality indicators (such as a chlorine content of less than 0.05%) that are equal to or better than similar commercial products at home and abroad.

[0060] Furthermore, the equipment for implementing the synthesis method of di(2-ethylhexyl) peroxydicarbonate of the present invention can ensure that the treatment method is carried out efficiently and orderly, and the thermal risk of using the equipment is low and the production efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 The invention shows an equipment flow chart of a method for synthesizing di(2-ethylhexyl) peroxydicarbonate.

[0062] Figure 2 Another equipment flow chart of the method for synthesizing di(2-ethylhexyl) peroxydicarbonate of the present invention is shown. DETAILED DESCRIPTION

[0063] Various exemplary embodiments, features and aspects of the present invention will be described in detail below. The word "exemplary" used here means "used as an example, embodiment or illustrative". Any embodiment described here as "exemplary" is not necessarily interpreted as being superior or better than other embodiments.

[0064] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In other examples, methods, means, equipment and steps well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0065] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0066] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0067] In this specification, unless otherwise specified, the word "multiple" in "multiple", "multiple", "plurality", etc. means a numerical value of 2 or more.

[0068] In this specification, the unit names used are all international standard unit names, and unless otherwise stated, the "%" used indicates weight or mass percentage.

[0069] In this specification, "about" is used to define the numerical range and parameters of the present invention. All numerical values ​​are approximate, and the specific relevant numerical values ​​are presented as accurately as possible. Unless otherwise expressly stated, it should be understood that all ranges, quantities, values ​​and percentages used in the present invention are modified by "about". Here, "about" usually means that the actual value is within ±5%, ±3%, ±1% or ±0.5% of a particular value or range.

[0070] In this specification, the references to "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0071] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints A and B.

[0072] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0073] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 23±2°C.

[0074] In this specification, the active oxygen content (AO) is the number of free radicals generated after the decomposition of a certain weight of peroxide. The theoretical active oxygen content refers to the content of peroxide bonds (-OO-) in the peroxide. The active oxygen content is expressed as the percentage of the atomic weight of active oxygen in one molecule of peroxide divided by the molecular weight of the peroxide. In other words, the active oxygen content in the peroxide molecule can be calculated as 16p / Mw, where p is the number of peroxide bonds (-OO-) in the peroxide molecule and Mw is the molecular weight of the peroxide molecule. In the case of pure products, this value represents the number of active oxygen in one molecule of peroxide (theoretical amount), and in the case of industrial products and diluted products, this value represents purity and concentration. For example, the molecular weight of di(2-ethylhexyl) peroxydicarbonate is 346.47, and its theoretical active oxygen content is about 4.62%.

[0075] <First aspect>

[0076] A first aspect of the present invention provides a method for synthesizing di(2-ethylhexyl) peroxydicarbonate, comprising the steps of:

[0077] Passing an alkaline solution, a hydrogen peroxide solution and a 2-ethylhexyl chloroformate solution through a microreactor and performing a preliminary reaction to obtain a first oil-water mixture, wherein before the preliminary reaction, the alkaline solution, the hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution have been mixed through a micromixer;

[0078] The first oil-water mixture is transported to an aging reactor to continue the reaction to obtain a second oil-water mixture;

[0079] performing liquid separation treatment on the second oil-water mixture and obtaining an oil phase;

[0080] The oil phase is post-treated to obtain di(2-ethylhexyl) peroxydicarbonate.

[0081] The present invention allows alkaline solution, hydrogen peroxide solution and 2-ethylhexyl chloroformate solution to mix in a micro-mixer and then enter a micro-reactor and perform a preliminary reaction, so that alkaline solution, hydrogen peroxide solution and 2-ethylhexyl chloroformate solution can be liquid-liquid mixed and / or liquid-liquid dispersed in the micro-mixer. Since the micro-mixer can increase the contact specific surface area between alkaline solution, hydrogen peroxide solution and 2-ethylhexyl chloroformate solution, the materials before the reaction are mixed and / or dispersed more uniformly, which is conducive to subsequent reactions. Specifically, a pump (such as a horizontal flow pump, a diaphragm pump, a magnetic pump, a centrifugal pump, etc.) can be used to pass the raw materials into the micro-mixer.

[0082] In some specific embodiments, in the alkaline solution, the concentration of the alkaline substance is 1 to 30 wt%, preferably 3 to 12 wt%, for example, it can be 2 wt%, 4 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, etc.; in the hydrogen peroxide solution, the concentration of hydrogen peroxide is 20 to 60 wt%, preferably 30 to 50 wt%, for example, it can be 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, etc.; in the 2-ethylhexyl chloroformate solution, the concentration of 2-ethylhexyl chloroformate is 50 to 100 wt%, preferably 75 to 100 wt%, for example, it can be 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, 95 wt%, 98 wt%, etc.; when the concentrations of the three reaction materials are within the above ranges, the reaction can be effectively carried out.

[0083] In some specific embodiments, the molar ratio of the alkaline substance to the 2-ethylhexyl chloroformate is (1-2):1, preferably (1-1.3):1, for example, 1:1, 1.1:1, 1.15:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, etc.; the molar ratio of the hydrogen peroxide to the 2-ethylhexyl chloroformate is (0.5-1):1, preferably (0.7-0.9):1, for example, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, etc. By making the molar ratio of the alkaline substance to the hydrogen peroxide relative to the 2-ethylhexyl chloroformate within the above range, the 2-ethylhexyl chloroformate can be fully converted and the conversion rate can be adjusted.

[0084] In other specific embodiments, the volume flow ratio of the alkaline solution to the 2-ethylhexyl chloroformate solution is (0.35-10):1, for example, 0.5:1, 0.8:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1. 1, 9:1, 9.5:1, etc.; the volume flow ratio of the hydrogen peroxide solution to the 2-ethylhexyl chloroformate solution is (0.05-1.2):1, for example, 0.05:1, 0.08:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, etc. By making the volume flow ratio of the alkaline substance and hydrogen peroxide relative to 2-ethylhexyl chloroformate within the above range, 2-ethylhexyl chloroformate can be fully converted and the conversion rate can be adjusted.

[0085] Furthermore, by adjusting the amount of the inlet liquid in the micromixer, the volume flow ratio of the alkaline solution to the 2-ethylhexyl chloroformate solution is (0.35-10):1, and the volume flow ratio of the hydrogen peroxide solution to the 2-ethylhexyl chloroformate solution is (0.05-1.2):1.

[0086] Specifically, the present invention does not specifically limit the solvent for dissolving the alkaline substance or hydrogen peroxide, and it can be any feasible polar solvent in the art, preferably water. The present invention also does not specifically limit the solvent for dissolving 2-ethylhexyl chloroformate, and it can be an oily solvent commonly used in the art, for example, it can be isododecane or solvent oil or a mixture of the two.

[0087] The present invention does not specifically limit the alkaline substance, and it can be a strong alkaline substance commonly used in the art, such as sodium hydroxide or potassium hydroxide.

[0088] In some specific embodiments, since the reaction rate gradually becomes slow in the later stage, the complete conversion of materials in the microreactor requires a significant increase in the reactor volume, such as the length of the coil, which in turn greatly increases the pressure drop, resulting in increased equipment costs and operating costs, which is not conducive to process economy. Therefore, the present invention transports the first oil-water mixture obtained by the preliminary reaction to the aging reactor for continued reaction to obtain the second oil-water mixture. Specifically, the aging reactor is a small or conventional reactor operated in a continuous flow, for example, it can be a series connection of multiple small continuous stirred tank reactors, which can ensure sufficient reaction, reduce pressure drop, save equipment costs, and ensure that the flow is close to plug flow.

[0089] By conveying the first oil-water mixture obtained by the preliminary reaction to the aging reactor for further reaction, 2-ethylhexyl chloroformate can be completely converted. In some specific embodiments, the temperature in the aging reactor is 0-45°C, and the total residence time in the aging reactor is 10-180 minutes, for example, 30 minutes, 50 minutes, 80 minutes, 100 minutes, 120 minutes, 150 minutes, etc. By continuing the reaction in the reactor for 10-180 minutes, both the complete conversion of the reactants and the process efficiency can be achieved. In some specific embodiments, the pressure in the aging reactor is 3-7 bar. By controlling the pressure of the aging reactor within the above range, the decomposition of hydrogen peroxide can be effectively suppressed, which saves the reaction materials and avoids the shortening of the residence time caused by the gas generated by the decomposition of hydrogen peroxide.

[0090] Specifically, the present invention has no particular limitation on the micro mixer, which can be any micro mixer known in the art that is suitable for liquid-liquid mixing, such as a microchannel mixer, a membrane dispersion mixer, or a micro-mesh mixer, etc. The present invention also has no particular limitation on the microreactor, which can be any microreactor known in the art that is suitable for liquid phase reaction, such as a coil microreactor, a micro packed bed reactor, or a microchannel reactor, etc., wherein a coil microreactor is preferred, and the diameter of the coil can be 0.25 to 5 mm.

[0091] In the present invention, when the alkaline solution, the hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution are directly mixed in a micro mixer (i.e., equivalent to the case where the volume of the first microreactor approaches 0), an alkaline solution with a lower concentration is generally used, and the mixed product of the three substances is a colorless liquid containing a small amount of bubbles.

[0092] In some specific embodiments, the micromixer includes a first micromixer and a second micromixer, and the microreactor includes a first microreactor and a second microreactor; wherein,

[0093] The alkaline solution and the hydrogen peroxide solution are mixed in the first micro-mixer and then enter the first micro-reactor for reaction to obtain an alkaline hydrogen peroxide solution;

[0094] The alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution are liquid-liquid dispersed in the second micromixer and then enter the second microreactor for preliminary reaction to obtain a first oil-water mixed liquid.

[0095] The present invention uses a first micro mixer to mix an alkaline solution and a hydrogen peroxide solution. Since the internal size of the first micro mixer is small enough, the alkaline solution and the hydrogen peroxide solution can be fully mixed by contact. Specifically, a pump (such as a horizontal flow pump, a diaphragm pump, a magnetic pump, a centrifugal pump, etc.) can be used to pass the alkaline solution and the hydrogen peroxide solution into the first micro mixer. In addition, the amount ratio of the alkaline solution to the hydrogen peroxide solution can be adjusted by adjusting the flow rate of the alkaline solution and the hydrogen peroxide solution into the first micro mixer. Specifically, the volume flow ratio of the alkaline solution to the hydrogen peroxide solution can be 1: (0.05-1), for example, it can be 1: 0.06, 1: 0.08, 1: 0.1, 1: 0.2, 1: 0.3, 1: 0.4, 1: 0.5, 1: 0.6, 1: 0.7, 1: 0.8, 1: 0.9, etc.

[0096] In some specific embodiments, the temperature in the first micro mixer is 0-45°C, preferably 5-30°C, more preferably 10-20°C, for example, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, etc. By controlling the temperature in the first micro mixer at 0-45°C, especially at 5-30°C, the alkaline hydrogen peroxide solution can be stably prepared to reduce or avoid the decomposition of hydrogen peroxide. The mixing time in the first mixer is 0.1-10s, for example, 0.5s, 0.8s, 1s, 3s, 5s, 7s, 9s, etc. By setting the mixing time to 0.1-10s, the production efficiency can be taken into account while ensuring sufficient mixing.

[0097] It should be noted that the first micro-mixer mainly mixes the alkaline solution and the hydrogen peroxide solution, but at the same time, an acid-base reaction (deprotonation reaction) also occurs between a certain amount of sodium hydroxide and hydrogen peroxide.

[0098] The present invention uses the first microreactor to react an alkaline solution with a hydrogen peroxide solution, wherein the reaction is a process in which hydrogen peroxide is deprotonated in the presence of an alkaline substance to generate an alkaline hydrogen peroxide solution.

[0099] In some specific embodiments, the temperature in the first microreactor is 0-45°C, preferably 5-30°C, more preferably 10-20°C, for example, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, etc. By controlling the temperature in the first microreactor to 0-45°C, especially at 5-30°C, an alkaline hydrogen peroxide solution can be stably prepared to reduce or avoid the decomposition of hydrogen peroxide. The residence time of the first microreactor is 0.01-5min, preferably 0.1-0.5min, for example, 0.2min, 0.4min, 0.6min, 0.8min, 1min, 2min, 3min, 4min, etc. By controlling the residence time in the first microreactor to 0.01-5min, the equipment volume and investment can be reduced while ensuring a stable and complete reaction.

[0100] In some specific embodiments, the present invention is carried out by liquid-liquid dispersion of alkaline hydrogen peroxide solution and 2-ethylhexyl chloroformate solution in a second micromixer, and the alkaline hydrogen peroxide solution and 2-ethylhexyl chloroformate solution are fully mixed. In the present invention, the alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution are two immiscible solutions. When the alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution are pre-mixed in the second micromixer, since the internal size of the second micromixer is very small, the specific surface area when the oil-water two phases are in contact is very large, and the shearing effect is very strong, the alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution can be mixed in the second micromixer and immediately achieve good dispersion.

[0101] Specifically, a pump (e.g., a horizontal flow pump, a diaphragm pump, a magnetic pump, a centrifugal pump, etc.) can be used to pass the alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution into the second micromixer. In addition, the amount ratio of the alkaline hydrogen peroxide solution to the 2-ethylhexyl chloroformate solution can be adjusted by adjusting the flow rate of the alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution into the second micromixer. In some specific embodiments, the volume flow ratio of the alkaline solution to the 2-ethylhexyl chloroformate solution is (0.5-5):1, for example, it can be 0.8:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, etc.

[0102] In some specific embodiments, the temperature in the second micromixer is 0 to 50°C, preferably 20 to 40°C, for example, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, etc.; by controlling the temperature in the second micromixer to 0 to 50°C, good dispersion of the liquid-liquid two phases can be achieved, while reducing or avoiding the decomposition of hydrogen peroxide. The mixing time in the second micromixer is 0.1 to 10s, for example, 0.5s, 1s, 3s, 5s, 7s, 9s, etc.; by controlling the mixing time to 0.1 to 10s, production efficiency can be taken into account while ensuring good dispersion.

[0103] It should be noted that the second micromixer mainly performs dispersion between the alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution, but at the same time, a certain amount of 2-ethylhexyl chloroformate and the substances contained in the aqueous phase will also react, so a certain amount of di(2-ethylhexyl) peroxydicarbonate will also be produced after mixing in the second micromixer.

[0104] The present invention uses a second microreactor to make an alkaline hydrogen peroxide solution and a 2-ethylhexyl chloroformate solution perform a preliminary reaction to obtain a first oil-water mixed solution. In the microreactor, the alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution oil-water two phases contact each other to cause a peroxidation reaction.

[0105] In some specific embodiments, the reaction temperature in the second microreactor is 0 to 50°C, preferably 20 to 40°C, for example, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, etc. By controlling the temperature in the second microreactor to 0 to 50°C, the reaction can be carried out quickly and stably while taking into account the heat exchange capacity of the reactor. The residence time in the second microreactor is 0.1 to 20min, preferably 0.5 to 10min, for example, 1min, 2min, 3min, 4min, 6min, 8min, 10min, 12min, 15min, 18min, etc. By controlling the residence time in the second microreactor to 0.1 to 20min, the equipment volume and investment can be reduced while ensuring the highest possible reaction conversion rate.

[0106] In some specific embodiments, the first micromixer and the second micromixer of the present invention are the same or different, both are micromixers, which can be microchannel mixers, membrane dispersion mixers or microsieve mixers, etc.; the first microreactor and the second microreactor of the present invention are the same or different, both are microreactors, which can be coil microreactors, micropacked bed reactors or microchannel reactors, etc.

[0107] In some specific embodiments, the first oil-water mixture obtained after the reaction in the second microreactor is transported to the aging reactor to continue the reaction, and the obtained second oil-water mixture can be separated into two phases of liquid after standing, and the appearance of the oil-water two phases is transparent to milky white. By separating the water phase without di(2-ethylhexyl) peroxydicarbonate from the oil phase, an oil phase with a high purity of di(2-ethylhexyl) peroxydicarbonate is obtained. In order to further obtain an oil phase with a lower impurity content, the oil phase after oil-water separation can be post-processed.

[0108] In some specific embodiments, the post-treatment comprises one or more of washing, drying and microporous membrane filtration.

[0109] The washing is performed by washing with a washing liquid. The washing liquid is used to wash away a small amount of residual chloroformate or other acidic substances or salt impurities in the oil phase, thereby obtaining a purer di(2-ethylhexyl) peroxydicarbonate. During the washing, the temperature can be controlled at 5 to 30° C., preferably 15 to 25° C.

[0110] The present invention does not specifically limit the washing liquid, and it can be any feasible washing liquid in the art. Specifically, the washing liquid is an inorganic salt aqueous solution with a concentration of 0 to 10 wt%, and specifically, the concentration of the inorganic salt aqueous solution can be 0 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 7 wt%, 9 wt%, etc. By using the washing liquid to wash the oil phase, the impurities remaining in the oil phase can be effectively removed from the oil phase.

[0111] Furthermore, the volume ratio of the washing liquid to the washed oil phase is (0.3-3):1, for example, it can be 0.5:1, 0.8:1, 1:1, 1.5:1, 2:1, 2.5:1, etc.

[0112] In some specific embodiments, the inorganic salt is selected from an inorganic salt of an alkali metal or an alkaline earth metal. For example, it can be one or more of a halide, sulfate, carbonate, bicarbonate, nitrate, phosphate, etc. of an alkali metal or an alkaline earth metal. In some specific embodiments, the inorganic salt can be selected from one or more of an alkali metal carbonate or bicarbonate, preferably one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate. In the present invention, the washing liquid can be used multiple times between multiple production batches.

[0113] Furthermore, after washing, oil-water separation can be performed to obtain the washed oil phase. Generally speaking, the washing and oil-water separation process can be performed 0 to multiple times, 0 times means that this step does not need to be performed, preferably 1 to 2 times. By controlling the number of washing times within the above range, efficiency can be taken into account while ensuring product quality indicators as much as possible.

[0114] The pH value of the washed oil phase is 5-7, and the inorganic chlorine and organic hydrolyzable chlorine content of the washed oil phase is ≤0.15%, preferably ≤0.05%.

[0115] For drying, the drying is performed using a desiccant and / or a drying gas. The present invention can remove water from the oil phase by drying. Preferably, the oil phase after washing is dehydrated. When the water content in the oil phase is sufficiently low, the drying step can also be omitted.

[0116] Specifically, the desiccant may be one or more of anhydrous sodium sulfate, anhydrous magnesium sulfate and anhydrous calcium chloride. The drying is achieved by stirring to suspend the desiccant solid in the oil phase. The mass ratio of the desiccant to the dried oil phase is (0.001-1):1, for example, it may be 0.005:1, 0.01:1, 0.03:1, 0.05:1, 0.08:1, 0.1:1, 0.3:1, 0.5:1, 0.8:1, etc. The drying time may be 0.5 min to 2 h, for example, it may be 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, 1 h, 1.5 h, etc.

[0117] The drying gas is dry air or dry nitrogen. In some specific embodiments, the temperature of the drying gas is 0-30° C., for example, 5° C., 10° C., 15° C., 20° C., 25° C., etc., and the dew point is lower than -40° C. Drying is achieved by blowing the gas into the oil phase, and the drying time is 0.5 min to 2 h, for example, 5 min, 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, 1 h, 1.5 h, etc.

[0118] In the filtration, the present invention separates the aqueous phase not containing di(2-ethylhexyl) peroxydicarbonate from the oil phase by using a microporous filter membrane to obtain an oil phase with high purity of di(2-ethylhexyl) peroxydicarbonate.

[0119] The microporous membrane filtration method of the present invention can replace drying, for example, the washed oil phase can be subjected to microporous membrane filtration.

[0120] The present invention does not specifically limit the microporous filter membrane, and it can be selected as needed. Specifically, the microporous filter membrane can be made of an oleophilic and hydrophobic material, such as polytetrafluoroethylene, polytetrafluorovinylidene, polypropylene, etc., and the average pore size of the filter membrane is 0.01 to 10 μm.

[0121] In some specific embodiments, the synthesis method further comprises the step of diluting the di(2-ethylhexyl) peroxydicarbonate with a diluent; preferably, the diluent comprises an oily solvent or an aqueous dispersion. For the oily solvent, for example, it can be isododecane or solvent oil or a mixture of the two. For the aqueous dispersion, for example, it can be one or more of water, methanol, ethanol, ethylene glycol, polyvinyl alcohol, and lactoferrin. Preferably, the aqueous dispersion is a mixture of water and methanol.

[0122] By mixing the finally obtained oil phase with a diluent, a di(2-ethylhexyl) peroxydicarbonate product is obtained. The finally obtained oil phase can be an oil phase obtained through post-treatment or an oil phase that does not require post-treatment.

[0123] <Second Aspect>

[0124] The second aspect of the present invention provides a device for implementing the synthesis method described in the first aspect of the present invention, wherein the device comprises a micro mixer, a micro reactor, an aging reactor and a liquid separator connected in sequence.

[0125] In some specific embodiments, the micromixer includes a first micromixer and a second micromixer, and the microreactor includes a first microreactor and a second microreactor; wherein the first micromixer, the first microreactor, the second micromixer and the second microreactor are connected in sequence.

[0126] In some specific embodiments, the liquid separator is further connected to one or more of a washing liquid separator, a dryer, a microporous membrane filter and a mixing tank.

[0127] By using the equipment of the present invention, the synthesis of di(2-ethylhexyl) peroxydicarbonate of the present invention can be ensured to be carried out efficiently and orderly, and the thermal risk of using the equipment is low and the production efficiency is high.

[0128] Example

[0129] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0130] The micro-reactor parameters used in the following examples are as follows:

[0131] (1) In accordance with Figure 1 Example

[0132] Micro mixer No. 1 is a T-type micro three-way mixer made of 316 stainless steel with a channel diameter of 0.50 mm.

[0133] Micro mixer No. 2 is a T-type micro three-way mixer made of 316 stainless steel with a channel diameter of 0.25 mm.

[0134] Microreactor No. 1 is a coil-type microreactor made of 316 stainless steel, with an inner diameter of 1.60 mm and adjustable length.

[0135] Microreactor No. 2 is a coil-type microreactor made of 316 stainless steel, with an inner diameter of 1.60 mm and adjustable length.

[0136] (2) In accordance with Figure 2 Example

[0137] Micro mixer No. 1 is a T-type micro three-way mixer made of 316 stainless steel with a channel diameter of 0.25 mm.

[0138] Microreactor No. 1 is a coil-type microreactor made of 316 stainless steel, with an inner diameter of 0.50 mm and adjustable length.

[0139] The active oxygen content described in the following examples was determined by iodine titration, with reference to the national standard GB / T32102-2015.

[0140] The contents of inorganic chlorine and organic hydrolyzable chlorine described in the following examples were determined by ammonium thiocyanate titration (or ion chromatography).

[0141] Embodiment 1:

[0142] like Figure 1As shown, 100.00g of sodium hydroxide was dissolved in 900.00g of water as feed liquid A. Untreated 30wt% hydrogen peroxide was used as feed liquid B. Untreated 98wt% chloroformic acid-2-ethylhexyl ester was used as feed liquid C. Feed liquid A and feed liquid B were respectively transported to micro mixer No. 1 using a horizontal flow pump. The mixer temperature was 10°C, the mixing time was 1s, the feed liquid A flow rate was 21.2mL / min, and the feed liquid B flow rate was 4.167mL / min. The mixed solution obtained by mixing enters micro reactor No. 1, the residence time in the reaction coil is 0.20min, and the reaction coil temperature is 20°C. The alkaline hydrogen peroxide solution obtained at the outlet of micro reactor No. 1 and the feed liquid C transported by the horizontal flow pump are liquid-liquid dispersed in micro mixer No. 2, the feed liquid C flow rate is 10.000mL / min, and the mixing time is 0.5s. At this time, the molar ratio of sodium hydroxide to 2-ethylhexyl chloroformate is 1.15:1, and the molar ratio of hydrogen peroxide to 2-ethylhexyl chloroformate is 0.8:1. The dispersed heterogeneous fluid enters microreactor No. 2, the temperature is controlled to 30°C, and the residence time in the reaction coil is 6.00min to obtain the first oil-water mixture. The first oil-water mixture continues to enter the aging reactor for stirring and reaction, and the total residence time is 150min. After the conversion is completed, the second oil-water mixture is obtained. The second oil-water mixture is separated to take the oil phase, and a 2wt% sodium bicarbonate solution is added to wash the oil phase. The volume ratio of the 2wt% sodium bicarbonate solution to the oil phase is 0.8:1, and then the oil phase is separated. Anhydrous sodium sulfate is added to the oil phase, and the mass ratio of anhydrous sodium sulfate to the oil phase is 0.05:1. The anhydrous sodium sulfate is suspended in the oil phase by stirring, and the drying time is 15min. The solid is separated from the oil phase by filtration. The obtained oil phase was analyzed to have an active oxygen content of 4.60%, and an inorganic chlorine and organic hydrolyzable chlorine content of 0.0232%. Isododecane was mixed with the oil phase at a mass ratio of 0.328:1 to obtain a 75% di(2-ethylhexyl) peroxydicarbonate solvent-based product.

[0143] Embodiment 2:

[0144] like Figure 1As shown, 100.00g of sodium hydroxide was dissolved in 900.00g of water as feed liquid A. Untreated 30wt% hydrogen peroxide was used as feed liquid B. Untreated 98wt% chloroformic acid-2-ethylhexyl ester was used as feed liquid C. Feed liquid A and feed liquid B were respectively transported to micro mixer No. 1 using a horizontal flow pump, the mixer temperature was 10°C, the mixing time was 0.8s, the feed liquid A flow rate was 21.2mL / min, and the feed liquid B flow rate was 4.167mL / min. The mixed solution obtained by mixing enters micro reactor No. 1, the residence time in the reaction coil is 0.20min, and the reaction coil temperature is 10°C. The alkaline hydrogen peroxide solution obtained at the outlet of micro reactor No. 1 and the feed liquid C transported by the horizontal flow pump are liquid-liquid dispersed in micro mixer No. 2, the feed liquid C flow rate is 10.000mL / min, and the mixing time is 0.5s. At this time, the molar ratio of sodium hydroxide to 2-ethylhexyl chloroformate is 1.15:1, and the molar ratio of hydrogen peroxide to 2-ethylhexyl chloroformate is 0.8:1. The dispersed heterogeneous fluid enters microreactor No. 2, the temperature is controlled to 30°C, and the residence time in the reaction coil is 8.00min to obtain the first oil-water mixture. The first oil-water mixture continues to enter the aging reactor for stirring and reaction, and the total residence time is 120min. After the conversion is completed, the second oil-water mixture is obtained. The second oil-water mixture is separated to take the oil phase, and a 2wt% sodium bicarbonate solution is added to wash the oil phase. The volume ratio of the 2wt% sodium bicarbonate solution to the oil phase is 0.8:1, and then the oil phase is separated. Anhydrous sodium sulfate is added to the oil phase, and the mass ratio of anhydrous sodium sulfate to the oil phase is 0.05:1. The anhydrous sodium sulfate is suspended in the oil phase by stirring, and the drying time is 15min. The solid is separated from the oil phase by filtration. The obtained oil phase was analyzed to have an active oxygen content of 4.61%, and an inorganic chlorine and organic hydrolyzable chlorine content of 0.0243%. A diluent was prepared according to a mass ratio of water to methanol of 1:1, and the diluent was mixed with the oil phase at a mass ratio of 0.996:1 to obtain a 50% di(2-ethylhexyl) peroxydicarbonate emulsion product.

[0145] Embodiment 3:

[0146] like Figure 2As shown, 40.00g of sodium hydroxide is dissolved in 960.00g of water as feed liquid A. Untreated 30wt% hydrogen peroxide is used as feed liquid B. Untreated 98wt% 2-ethylhexyl chloroformate is used as feed liquid C. Feed liquid A, feed liquid B and feed liquid C are respectively transported to micro mixer No. 1 using a horizontal flow pump. The mixer temperature is 40°C, the mixing time is 0.5s, the feed liquid A flow rate is 1.88mL / min, the feed liquid B flow rate is 0.14mL / min, and the feed liquid C flow rate is 0.335mL / min. At this time, the molar ratio of sodium hydroxide to 2-ethylhexyl chloroformate is 1.15:1, and the molar ratio of hydrogen peroxide to 2-ethylhexyl chloroformate is 0.8:1. The mixed and dispersed heterogeneous fluid enters microreactor No. 1, the temperature is controlled to 40°C, and the residence time in the reaction coil is 8.00min to obtain the first oil-water mixture. The first oil-water mixture continues to enter the aging reactor for stirring and reaction, and the total residence time is 100 minutes. After the conversion is completed, the second oil-water mixture is obtained. The second oil-water mixture is separated to obtain the oil phase, and 1wt% sodium carbonate solution is added to wash the oil phase. The volume ratio of 1wt% sodium carbonate solution to the oil phase is 1:1, and then the oil phase is separated. Anhydrous sodium sulfate is added to the oil phase, and the mass ratio of anhydrous sodium sulfate to the oil phase is 0.05:1. The anhydrous sodium sulfate is suspended in the oil phase by stirring, and the drying time is 20 minutes. The solid is separated from the oil phase by filtration. The obtained oil phase is analyzed to have an active oxygen content of 4.59%, and an inorganic chlorine and organic hydrolyzable chlorine content of 0.0189%. The diluent is configured according to the mass ratio of water and methanol of 1:1, and the diluent is mixed with the oil phase at a mass ratio of 0.987:1 to obtain a 50% peroxydicarbonate di(2-ethylhexyl) ester emulsion product.

[0147] Embodiment 4:

[0148] like Figure 2As shown, 40.00g of sodium hydroxide is dissolved in 960.00g of water as feed liquid A. Untreated 30wt% hydrogen peroxide is used as feed liquid B. Untreated 98wt% 2-ethylhexyl chloroformate is used as feed liquid C. Feed liquid A, feed liquid B and feed liquid C are respectively transported to micro mixer No. 1 using a horizontal flow pump. The mixer temperature is 30°C, the mixing time is 0.5s, the feed liquid A flow rate is 1.88mL / min, the feed liquid B flow rate is 0.14mL / min, and the feed liquid C flow rate is 0.335mL / min. At this time, the molar ratio of sodium hydroxide to 2-ethylhexyl chloroformate is 1.15:1, and the molar ratio of hydrogen peroxide to 2-ethylhexyl chloroformate is 0.8:1. The mixed and dispersed heterogeneous fluid enters microreactor No. 1, the temperature is controlled to 30°C, and the residence time in the reaction coil is 8.50min to obtain the first oil-water mixture. The first oil-water mixture continues to enter the aging reactor for stirring and reaction, with a total residence time of 120 minutes. After the conversion is completed, the second oil-water mixture is obtained. The second oil-water mixture is separated to take the oil phase, and 1wt% sodium carbonate solution is added to wash the oil phase. The volume ratio of 1wt% sodium carbonate solution to the oil phase is 1:1, and then the oil phase is separated. Anhydrous sodium sulfate is added to the oil phase, and the mass ratio of anhydrous sodium sulfate to the oil phase is 0.05:1. The anhydrous sodium sulfate is suspended in the oil phase by stirring, and the drying time is 30 minutes. The solid is separated from the oil phase by filtration. The obtained oil phase is analyzed to have an active oxygen content of 4.54%, and an inorganic chlorine and organic hydrolyzable chlorine content of 0.0134%. Isododecane is mixed with the oil phase at a mass ratio of 0.965:1 to obtain a 50% peroxydicarbonate di(2-ethylhexyl) ester solvent-based product.

[0149] Comparative Example 1:

[0150] Compared with Example 1, the difference is that no aging reactor is set in this comparative example.

[0151] 100.00g of sodium hydroxide was dissolved in 900.00g of water as feed liquid A. Untreated 30wt% hydrogen peroxide was used as feed liquid B. Untreated 98wt% chloroformic acid-2-ethylhexyl ester was used as feed liquid C. Feed liquid A and feed liquid B were respectively transported to micro mixer No. 1 using a horizontal flow pump. The mixer temperature was 10°C, the mixing time was 1s, the feed liquid A flow rate was 21.2mL / min, and the feed liquid B flow rate was 4.167mL / min. The mixed liquid entered micro reactor No. 1, the residence time in the reaction coil was 0.20min, and the reaction coil temperature was 20°C. The alkaline hydrogen peroxide solution obtained at the outlet of micro reactor No. 1 and the feed liquid C transported by the horizontal flow pump were liquid-liquid dispersed in micro mixer No. 2. The feed liquid C flow rate was 10.000mL / min and the mixing time was 0.5s. At this time, the molar ratio of sodium hydroxide to 2-ethylhexyl chloroformate is 1.15:1, and the molar ratio of hydrogen peroxide to 2-ethylhexyl chloroformate is 0.8:1. The dispersed heterogeneous fluid enters microreactor No. 2, the temperature is controlled to 30°C, the residence time in the reaction coil is 6.00min, and the first oil-water mixture is obtained. The first oil-water mixture is separated to take the oil phase, and a 2wt% sodium bicarbonate solution is added to wash the oil phase, the volume ratio of the 2wt% sodium bicarbonate solution to the oil phase is 0.8:1, and then the oil phase is separated. Anhydrous sodium sulfate is added to the oil phase, the mass ratio of anhydrous sodium sulfate to the oil phase is 0.05:1, and the anhydrous sodium sulfate is suspended in the oil phase by stirring. The drying time is 15min, and the solid is separated from the oil phase by filtration. The obtained oil phase is analyzed to have an active oxygen content of 3.15%, and an inorganic chlorine and organic hydrolyzable chlorine content of 5.86%.

[0152] Comparative Example 2:

[0153] Compared with Example 3, the difference is that no aging reactor is set in this comparative example.

[0154] Dissolve 40.00g of sodium hydroxide in 960.00g of water as feed liquid A. Use untreated 30wt% hydrogen peroxide as feed liquid B. Use untreated 98wt% 2-ethylhexyl chloroformate as feed liquid C. Feed liquid A, feed liquid B and feed liquid C are respectively transported to micro mixer No. 1 using a horizontal flow pump. The mixer temperature is 40°C, the mixing time is 0.5s, the feed liquid A flow rate is 1.88mL / min, the feed liquid B flow rate is 0.14mL / min, and the feed liquid C flow rate is 0.335mL / min. At this time, the molar ratio of sodium hydroxide to 2-ethylhexyl chloroformate is 1.15:1, and the molar ratio of hydrogen peroxide to 2-ethylhexyl chloroformate is 0.8:1. The mixed and dispersed heterogeneous fluid enters microreactor No. 1, the temperature is controlled at 40°C, and the residence time in the reaction coil is 8.00min to obtain the first oil-water mixture. The first oil-water mixture was separated to obtain the oil phase, and a 1wt% sodium carbonate solution was added to wash the oil phase, the volume ratio of the 1wt% sodium carbonate solution to the oil phase was 1:1, and then the oil phase was separated. Anhydrous sodium sulfate was added to the oil phase, the mass ratio of anhydrous sodium sulfate to the oil phase was 0.05:1, and the anhydrous sodium sulfate was suspended in the oil phase by stirring, the drying time was 20 minutes, and the solid was separated from the oil phase by filtering. The obtained oil phase was analyzed to have an active oxygen content of 3.63%, and an inorganic chlorine and organic hydrolyzable chlorine content of 3.94%.

[0155] The quality indicators of the oil phases obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were measured, and the results are shown in Table 1.

[0156] Table 1:

[0157]

[0158] It should be noted that, although the technical solution of the present invention is introduced with specific examples, those skilled in the art will appreciate that the present invention should not be limited thereto.

[0159] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for synthesizing di(2-ethylhexyl) peroxydicarbonate, characterized in that: The following steps are involved: The alkaline solution, the hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution are subjected to a preliminary reaction via a microreactor to obtain a first oil-water mixture, wherein before the preliminary reaction, the alkaline solution, the hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution have been mixed via a micromixer; The first oil-water mixture is transported to an aging reactor to continue the reaction to obtain a second oil-water mixture; performing liquid separation treatment on the second oil-water mixture and obtaining an oil phase; The oil phase is post-treated to obtain di(2-ethylhexyl) peroxydicarbonate.

2. The synthesis method according to claim 1, characterized in that In the alkaline solution, the concentration of the alkaline substance is 1 to 30 wt %; In the hydrogen peroxide solution, the concentration of hydrogen peroxide is 20 to 60 wt %; In the 2-ethylhexyl chloroformate solution, the concentration of 2-ethylhexyl chloroformate is 50-100 wt %.

3. The synthesis method according to claim 2, characterized in that The molar ratio of the alkaline substance to the 2-ethylhexyl chloroformate is (1-2):1; The molar ratio of the hydrogen peroxide to the 2-ethylhexyl chloroformate is (0.5-1):

1.

4. The synthesis method according to any one of claims 1 to 3, characterized in that The micro mixer is a microchannel mixer, a membrane dispersion mixer or a micro mesh mixer; The microreactor is a coil microreactor, a micro packed bed reactor or a micro channel reactor.

5. The synthesis method according to any one of claims 1 to 4, characterized in that The micro mixer includes a first micro mixer and a second micro mixer, and the micro reactor includes a first micro reactor and a second micro reactor; wherein, The alkaline solution and the hydrogen peroxide solution are mixed in the first micro-mixer and then enter the first micro-reactor for reaction to obtain an alkaline hydrogen peroxide solution; The alkaline hydrogen peroxide solution and the 2-ethylhexyl chloroformate solution are liquid-liquid dispersed in the second micromixer and then enter the second microreactor for preliminary reaction to obtain a first oil-water mixed liquid.

6. The synthesis method according to claim 5, characterized in that The temperature in the first micro mixer is 0 to 45° C., and the mixing time is 0.1 to 10 seconds; The temperature in the first microreactor is 0 to 45°C, and the residence time is 0.01 to 5 min; The temperature in the second micro mixer is 0 to 50° C., and the mixing time is 0.1 to 10 seconds; The temperature in the second microreactor is 0 to 50°C, and the residence time is 0.1 to 20 min; The temperature in the aging reactor is 0-45° C., and the residence time is 10-180 min.

7. The synthesis method according to any one of claims 1 to 6, characterized in that The post-treatment includes one or more of washing, drying and microporous membrane filtration.

8. The synthesis method according to claim 7, characterized in that The washing is performed by using a washing liquid; the washing liquid is an inorganic salt aqueous solution with a concentration of 0 to 10 wt%; and / or, The drying is performed by using a desiccant and / or a dry gas; the desiccant includes one or more of anhydrous sodium sulfate, anhydrous magnesium sulfate and anhydrous calcium chloride; the dry gas is dry air or dry nitrogen; and / or, The filtration is performed using a microporous filter membrane with an average pore size of 0.01 to 10 μm; the microporous filter membrane is made of an oleophilic and hydrophobic material.

9. The synthesis method according to any one of claims 1 to 8, characterized in that The synthesis method further comprises the step of diluting the di(2-ethylhexyl) peroxydicarbonate with a diluent; preferably, the diluent comprises an oily solvent or an aqueous dispersion.

10. A device for implementing the synthesis method according to any one of claims 1 to 9, characterized in that: The equipment comprises a micro mixer, a micro reactor, an aging reactor and a liquid separator which are connected in sequence; The micromixer includes a first micromixer and a second micromixer, and the microreactor includes a first microreactor and a second microreactor; wherein the first micromixer, the first microreactor, the second micromixer and the second microreactor are connected in sequence; Preferably, the liquid separator is further connected to one or more of a washing liquid separator, a dryer, a microporous membrane filter and a mixing tank.

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