Preparation method of diene liquid rubber

Abstract

The invention discloses a preparation method of diene liquid rubber, which comprises the following steps: sequentially adding an organic solvent, a regulator and a monomer into a monomer solution storage tank, and stirring to uniformly mix the materials; sequentially adding a non-polar solvent and an initiator into the initiator solution storage tank, and starting stirring to uniformly mix the materials; after the temperature of the micro-channel reactor is controlled to a polymerization temperature and backpressure is carried out, materials in the monomer solution storage tank and the initiator solution storage tank are continuously conveyed into the micro-channel reactor to be mixed and react; after the reaction is started, materials in the monomer solution storage tank and the initiator solution storage tank are still continuously conveyed into the microchannel reactor for reaction, and after the polymerization reaction is completed, a terminator is added into the polymerization kettle for terminating; and washing to remove residual metal, and drying in vacuum to obtain the diene liquid rubber. According to the preparation method, room-temperature initiation can be realized, and the temperature change of the polymerization reaction can be controlled within + / -3 DEG C.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and particularly to a method for preparing diene liquid rubber with a high monomer raw material concentration. Background Art

[0002] Liquid rubber generally refers to oligomers with a number average molecular weight between 500 and 10,000, which are viscous and flowable liquids at room temperature. Compared with traditional rubber products, liquid rubber has the advantages of good fluidity, easy processing, and easy continuous production, and is known as the "new generation of gold rubber". Diene liquid rubber accounts for more than 70% of the liquid rubber market share and has excellent properties such as elasticity, cold resistance, adhesiveness, insulation, and hydrophobicity, and has a wide range of applications in the fields of aerospace, electronic packaging, and the automotive industry. The preparation methods of diene liquid rubber include free radical polymerization, anionic polymerization, coordination polymerization, high polymer degradation, and chain end chemical transfer methods, etc. Currently, industrial production usually uses free radical polymerization and anionic polymerization. Compared with free radical polymerization, anionic polymerization has the advantages of adjustable microstructure and narrow polymer molecular weight distribution. However, when using anionic polymerization to prepare liquid rubber, the amount of initiator added is relatively large, usually 30 to 50 times that of solid rubber. The initiator is generally alkyl lithium, and the cost is relatively high. When using traditional batch polymerization, there are problems such as concentrated heat release, intense local heat release, and difficult temperature rise control, which make it difficult to control the polymerization structure and result in a wide molecular weight distribution. Generally, problems such as engineering heat release are solved by reducing the monomer concentration (below 10%), and it is an intermittent polymerization or semi-batch polymerization, making it difficult to improve production efficiency. Therefore, there is an urgent need to develop a safe and efficient liquid rubber polymerization process.

[0003] To solve the above problems, Chinese invention patent CN109796550 A discloses a method for preparing low molecular weight liquid rubber. Using an anionic living polymerization method, a solvent, a monomer, and an initiator are added in sequence, and a chain transfer agent is added multiple times at different time intervals to control the molecular weight, thereby obtaining low molecular weight liquid rubber. Although this method reduces the amount of initiator used, the amount of chain transfer agent used is relatively large and it is added multiple times, and the polymerization process is complex.

[0004] Chinese invention patent CN10561770A discloses a polyhydroxylated polybutadiene rubber and a controllable preparation method thereof. This method first reacts commercialized cis-butadiene rubber with an epoxidizing reagent to obtain epoxidized cis-butadiene rubber, oxidatively cleaves it to obtain epoxidized terminal aldehyde group polybutadiene liquid rubber, and finally reduces it to prepare polyhydroxylated polybutadiene liquid rubber. However, this method has problems such as a wide molecular weight distribution and difficult microstructure control.

[0005] Chinese invention patent CN114656583A discloses a method for preparing functionalized liquid 1,2-polybutadiene rubber, which is to synthesize 1.2-polybutadiene rubber by a solution method under the catalysis of a coordination catalyst at a certain polymerization temperature. After a period of polymerization, the polymerization temperature is adjusted and a bio-based polar small molecule additive and an olefin metathesis catalyst are added to obtain a functionalized liquid 1.2-polybutadiene rubber. However, this method requires the addition of an olefin catalyst and a functional monomer during the reaction, which is a complex process, and the catalyst is difficult to remove, resulting in a high cost.

[0006] "Synthesis and Application of Hydroxyl-Terminated Diene Liquid Rubber" discloses a method for preparing a series of hydroxyl-terminated polydiene liquid rubbers by anionic polymerization, using naphthalene lithium initiator, butadiene dilithium initiator and 3-(tert-dimethylsiloxane)-1-propyl lithium to synthesize dihydroxyl-terminated liquid styrene butadiene rubber. However, the initiator preparation of this method is difficult and the initiation temperature is high.

[0007] Chinese invention patent CN103087364A discloses a liquid rubber and a preparation method thereof, wherein olefins are polymerized under anionic polymerization conditions using an organic lithium compound in a non-polar organic solvent, and are simultaneously or successively contacted with water / or C1-C6 alcohol and a gas containing 10-100% by volume of carbon dioxide, and then the product is heated and dried and / vacuum dried in the presence of an antioxidant and / or under stirring conditions. However, the vinyl content of the liquid butadiene rubber prepared by this method is low and the initiation temperature is high.

[0008] Chinese patent CN102702408A discloses a method for preparing a diene liquid rubber, characterized in that the method comprises the following steps: polymerizing butadiene or isoprene with an initiator and a non-polar organic solvent within a temperature range of 20-150°C for 20-180 minutes; adding a straight-chain organic dibasic acid with a carbon number of 2-12 to the polymerization product and contacting it at a temperature of 0-100°C for 3-150 minutes; stirring and mixing the product after contact with at least one of hindered phenols, ester-containing or phosphite antioxidants to obtain liquid rubber. However, the method adopts a one-time addition of materials and terminates by adding dibasic acid, and the residual dibasic acid is not environmentally friendly.

[0009] Chinese invention patent CN117003918A discloses a method for synthesizing liquid rubber based on a continuous flow microreactor and a continuous flow microreactor, wherein the liquid rubber is prepared by a continuous polymerization process, and the molecular weight of the obtained liquid rubber is accurately controlled and the molecular weight distribution is narrow. However, in the polymerization process of this method, the mass concentration of the monomer can only reach 40% at most, resulting in low production efficiency and high cost. If the mass concentration of the monomer is directly increased, the monomer gasification will be serious, the monomer and initiator feeding will be inaccurate, and the product conversion rate will be affected. SUMMARY OF THE INVENTION

[0010] One of the technical problems to be solved by the present invention is that when the prior art uses a microchannel reactor to synthesize liquid rubber, the monomer raw material mass concentration used is too low (only 40% at most), resulting in low production efficiency and high cost. The second technical problem to be solved by this application is that in the production process of diene liquid rubber by the prior art method, the polymerization reaction temperature varies greatly and the polymerization reaction environment is unstable.

[0011] In order to solve the above technical problems, the present invention provides a method for preparing diene liquid rubber. The preparation method comprises the following steps:

[0012] (1) Nitrogen or argon is introduced into the monomer solution storage tank for replacement, and organic solvent, regulator and monomer are added to the tank in sequence, pressurized, and stirred to mix the materials evenly;

[0013] (2) Introduce nitrogen or argon into the initiator solution storage tank for replacement, add non-polar solvent and initiator into the tank in sequence, pressurize, and start stirring to mix the materials evenly;

[0014] (3) The materials in the monomer solution storage tank and the initiator solution storage tank are not added all at once, but are added in a continuous feeding manner during the reaction process, specifically including: after the temperature of the microchannel reactor is controlled to the polymerization temperature and back pressure is applied, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously transported to the microchannel reactor for mixing and starting the reaction; after the reaction starts, the materials in the monomer solution storage tank and the initiator solution storage tank are still continuously transported to the microchannel reactor for reaction; after the materials in the monomer solution storage tank and the initiator solution storage tank are transported and the polymerization reaction is complete, a terminator is added to the polymerization kettle to terminate the reaction;

[0015] (4) washing to remove residual metals, vacuum drying to obtain diene liquid rubber;

[0016] Wherein, the mass of the monomer accounts for 50% to 80% of the total mass of the material.

[0017] As a further improvement of the present invention, the feeding and reaction of the microchannel reactor need to be carried out under the back pressure condition of the microchannel reactor, and the back pressure is 2.0 to 8.0 MPa, preferably 3.0 to 5.0 MPa.

[0018] As a further improvement of the present invention, in step (1), the organic solvent is a compound of a polar solvent and a non-polar solvent.

[0019] As a further improvement of the present invention, in step (1), the polar solvent is at least one of diethyl ether, dioxane, tetrahydrofuran, and dimethoxyethane; in step (1) or step (2), the non-polar solvent is at least one of hexane, cyclohexane, n-heptane, and n-octane; the mass ratio of the polar solvent in step (1) to the sum of the non-polar solvents in steps (1) and (2) is 0.1 to 0.3:1.

[0020] As a further improvement of the present invention, the regulator is a compound of a Lewis base polar regulator and a Lewis acid polar regulator, and the molar ratio of the Lewis base polar regulator to the Lewis acid polar regulator is 1:1 to 3.

[0021] As a further improvement of the present invention, the Lewis base polar regulator is one of tetramethylethylenediamine, diethylene glycol dimethyl ether, ethyltetrahydrofurfuryl ether, hexyltetrahydrofurfuryl ether, and bis(tetrahydrofurfuryl)propane; the Lewis acid polar regulator is one of potassium tert-butoxide, sodium tert-pentoxide, sodium mentholate, and sodium dodecylbenzenesulfonate.

[0022] As a further improvement of the present invention, the monomer is at least one of butadiene, isoprene, styrene, and myrcene.

[0023] As a further improvement of the present invention, the initiator is one of sec-butyl lithium and tert-butyl lithium.

[0024] As a further improvement of the present invention, the terminator is deionized water and an alcohol of C 1 -C 6 one of them.

[0025] As a further improvement of the present invention, the pressures of the monomer solution storage tank and the initiator solution storage tank are 0.01 to 4 MPa, preferably 0.5 to 2.5 MPa.

[0026] As a further improvement of the present invention, the conveying rates of the materials in the monomer solution storage tank and the initiator solution storage tank are 2 mL / min to 150 mL / min, preferably 20 mL / min to 60 mL / min, and the conveying ratio is 2 to 4:1, preferably 2 to 3:1.

[0027] As a further improvement of the present invention, the temperature of the reaction is 10 to 60 °C, preferably 10 to 30 °C.

[0028] As a further improvement of the present invention, the molar ratio of the regulator to the initiator is 1 to 3:1.

[0029] As a further improvement of the present invention, the mass of the monomer accounts for 55% to 70% of the total mass of the materials. The total mass of the materials in the present invention refers to the sum of the masses of the organic solvent, the regulator and the monomer added in step (1), and the organic solvent and the initiator added in step (2).

[0030] As a further improvement of the present invention, the residence time of the materials in the microchannel reactor is 4 min to 18 min, preferably 5 to 15 min.

[0031] As a further improvement of the present invention, the temperature of the vacuum drying is 95 to 120 °C, and the vacuum degree is -0.06 to 0.09 MPa.

[0032] As a further improvement of the present invention, the liquid holdup of the microchannel reactor is 50 to 5000 mL, and it is provided with a plurality of material outlets, and the residence time of the materials can be adjusted according to requirements.

[0033] The inventor found in the actual production process that when synthesizing liquid rubber by using a microchannel reactor, the mass concentration of the monomer needs to be controlled below 40%. If the concentration of the monomer is suddenly increased, it will cause serious gasification of the monomer, and it will also cause inaccurate feeding of the body and the initiator in the microchannel reactor, and it is impossible to reach a high conversion rate in the same time and other problems, which greatly limits the production efficiency and increases the cost. To solve this technical problem, the preparation method of the present invention realizes the purpose of increasing the monomer concentration to 50 to 80 wt% during the reaction process through the back pressure of the microchannel reactor, ensuring that the diene monomer in the microchannel reactor remains in a liquid state under a high monomer concentration system, ensuring the accuracy of the feeding of the monomer and the initiator, saving a large amount of solvents, and reducing the cost.

[0034] In addition, the feeding method of the materials in the preparation method of the present invention is different from the traditional kettle polymerization method. The feeding method of the materials is regulated. The materials are added in a continuous feeding manner during the reaction process. At the same time, a microchannel reactor is used, which can realize low-temperature initiation, and the change of the polymerization reaction temperature can be controlled within ±3 °C, solving the problems of large temperature change and unstable polymerization reaction environment during the polymerization reaction process.

[0035] Furthermore, in the preparation method of the present invention, by compounding a polar solvent in a non-polar solvent, the polar solvent plays a role in dissociating the active center, which can accelerate the reaction rate and reduce the energy consumption.

[0036] Furthermore, in the preparation method of the present invention, through the compounding of a Lewis base polarity regulator and a Lewis acid polarity regulator, the Lewis acid polarity regulator adjusts the activity of the active center by forming a stable bimetallic complex, changes the microstructure of the polymer and the polymerization reaction rate, and the Lewis base polarity regulator is used in combination to prepare a diene rubber with a high side group structure. When the same regulator is added, a liquid polybutadiene rubber with a high vinyl content can be prepared, and the vinyl content can reach up to more than 95%. Description of the Drawings

[0037] Figure 1 It is the NMR spectrum of liquid styrene-butadiene rubber.

[0038] Figure 2 NMR spectrum of liquid nitrile rubber.

[0039] Figure 3 Molecular weight spectrum of the liquid polybutadiene rubber in Example 4. Detailed Description of the Invention

[0040] The following is a detailed description of the embodiments of the present invention: These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. For the experimental methods without specific conditions noted in the following embodiments, they are usually carried out under conventional conditions.

[0041] Equipment:

[0042] The embodiment uses a microchannel reactor with a liquid holding capacity of 2000 mL, and there is an outlet at every 500 mL, which is connected to a polymerization reaction kettle. The high-pressure cross-flow delivery pump is a plunger pump. The monomer solution storage tank, initiator solution storage tank, polymerization reaction kettle, and vacuum drying kettle are all equipment with stirring that meet the requirements of anionic polymerization.

[0043] Evaluation and Analysis Method:

[0044] Molecular weight and its distribution: Take about 10 mg of liquid rubber, dissolve it in THF in a 5 mL volumetric flask, filter to remove the insoluble impurities therein, the eluent is tetrahydrofuran, the flow rate is 1.0 mL / min, and the test temperature is 30 °C.

[0045] Nuclear magnetic resonance spectroscopy test: Take a small amount of liquid rubber and dissolve it with deuterated chloroform (CDCl 3 ), and scan it at a frequency of 400 MHz. The chemical shift is obtained with tetramethylsilane as the internal standard to obtain the NMR spectrum.

[0046] Example 1

[0047] The preset number-average molecular weight is 3000, and the monomer mass percentage is 75%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 554.37 g of hexane, 200.0 g of tetrahydrofuran, 97.63 g of ethyl tetrahydrofurfuryl ether, 84.75 g of sodium tert-pentoxide, and 4500 g of butadiene are successively added to the tank. Argon is filled to pressurize to 1.2 MPa, and stirring is started for 10 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 745.62 g of hexane and 1.5 mol of tert-butyl lithium are successively added to the tank. Argon is filled to pressurize to 1.2 MPa, and stirring is started for 10 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 20 °C and the back pressure to reach 3.5 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 80 mL / min and 20 mL / min respectively. The reaction starts, and the residence time of the materials in the microchannel reactor is 10 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously transported to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are transported completely and the polymerization reaction is complete, ethanol is added to terminate in the polymerization kettle, and then 1.5 times of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle. It is dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0048] Comparative Example 1

[0049] Compared with Example 1, in Comparative Example 1, no back pressure is applied, and the other conditions remain the same.

[0050] Table 1 Molecular weight and its distribution of Example 1 and Comparative Example 1

[0051] Preset molecular weight Number-average molecular weight of the product Molecular weight distribution Example 1 3000 3125 1.12 Comparative Example 1 3000 2156 2.30

[0052] As can be seen from Table 1, during the preparation process, without back pressure, due to the relatively high monomer concentration, the gasification of the monomer in the microchannel reactor is relatively serious, the reaction is not complete enough, and it affects the accuracy of the feeding rates of the monomer and the initiator, resulting in a relatively large deviation of the number-average molecular weight of the product, 2156, from the preset molecular weight of 3000.

[0053] Example 2

[0054] The preset number-average molecular weight is 3000, and the monomer mass percentage is 65%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 1061.48 g of hexane, 200.0 g of diethyl ether, 84.62 g of ethyl tetrahydrofurfuryl ether, 72.94 g of potassium tert-butoxide, and 3900.0 g of butadiene are sequentially added to the tank. Argon is filled to pressurize to 2.5 MPa, and stirring is started for 10 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 838.52 g of hexane and 1.3 mol of tert-butyl lithium are sequentially added to the tank. Argon is filled to pressurize to 2.5 MPa, and stirring is started for 10 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 15 °C and the back pressure to reach 3.2 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 80 mL / min and 20 mL / min respectively. The reaction starts, and the residence time of the materials in the microchannel reactor is 5 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously delivered to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are delivered and the polymerization reaction is complete, ethanol is added to terminate the reaction in the polymerization kettle, and then 2.0 times of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0055] Comparative Example 2

[0056] Compared with Example 2, in Comparative Example 2, no polar solvent is compounded. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 1259.13 g of hexane, 84.62 g of ethyl tetrahydrofurfuryl ether, 72.94 g of potassium tert-butoxide, and 3900.0 g of butadiene are sequentially added to the tank. Argon is filled to pressurize to 2.5 MPa, and stirring is started for 10 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 840.87 g of hexane and 1.3 mol of tert-butyl lithium are sequentially added to the tank. Argon is filled to pressurize to 2.5 MPa, and stirring is started for 10 min to make the materials mix evenly, and the other conditions remain the same.

[0057] Table 2 Molecular weight, its distribution and vinyl content of the product in Example 2 and Comparative Example 2

[0058] Preset molecular weight Number-average molecular weight of the product Molecular weight distribution Vinyl content Example 2 3000 3376 1.12 95.16％ Comparative Example 2 3000 2437 1.42 81.23％

[0059] As can be seen from Table 2, in the preparation process, without compounding polar solvents, the polymerization reaction rate is slow, the polymerization reaction is not complete enough within a short residence time, and the vinyl structure content of the product is low because the polar component solvent is not added and it does not play a role in the dissociation and structure regulation of the active center.

[0060] Example 3

[0061] The preset number average molecular weight is 4000, and the monomer mass percentage is 50%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 1462.45 g of hexane, 650.0 g of dioxane, 199.59 g of bis(tetrahydrofurfuryl) propane, 121.97 g of sodium dodecylbenzenesulfonate, and 3000 g of butadiene are sequentially added to the tank. Argon is filled to pressurize to 2.2 MPa, and stirring is started for 10 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 1666.71 g of hexane and 0.75 mol of tert-butyl lithium are sequentially added to the tank. Argon is filled to pressurize to 2.2 MPa, and stirring is started for 10 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 15 °C and the back pressure to reach 2.8 MPa, the high-pressure constant flow transfer pumps for the monomer solution and the initiator solution are started, and the transfer rates are 90 mL / min and 30 mL / min respectively. The reaction starts, and the residence time of the materials in the microchannel reactor is 16.67 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously transferred to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are transferred completely and the polymerization reaction is complete, ethanol is added to terminate in the polymerization kettle, and then 2.0 times of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle. It is dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0062] Comparative Example 3

[0063] Compared with Example 3, in Comparative Example 3, the compounding regulator is not used. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 1462.45 g of hexane, 650.0 g of dioxane, 261.36 g of sodium dodecylbenzenesulfonate, and 3000 g of butadiene are sequentially added to the tank, and the other conditions remain the same.

[0064] Table 3 Molecular weight, its distribution and vinyl content of the product in Example 3 and Comparative Example 3

[0065] Preset molecular weight Number-average molecular weight of the product Molecular weight distribution Vinyl content Example 3 4000 4180 1.12 97.36％ Comparative Example 3 4000 3841 1.23 71.65％

[0066] As can be seen from Table 3, in Comparative Example 3, the compounding of the regulator is not carried out, the regulation of the vinyl structure of the product is weakened, and the vinyl content is reduced.

[0067] Example 4

[0068] The preset number-average molecular weight is 4000, and the monomer mass percentage is 54.0%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 1566.18 g of hexane, 255.0 g of tetrahydrofuran, 52.72 g of ethyl tetrahydrofurfuryl ether, 45.45 g of potassium tert-butoxide, and 3240.0 g of butadiene are successively added to the tank. Argon is filled to pressurize to 1.2 MPa, and stirring is started for 10 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 938.82 g of hexane and 0.81 mol of tert-butyl lithium are successively added to the tank. Argon is filled to pressurize to 1.2 MPa, and stirring is started for 10 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 25°C and the back pressure to reach 4.0 MPa, the high-pressure constant-flow transfer pumps for the monomer solution and the initiator solution are started, and the transfer rates are 120 mL / min and 30 mL / min respectively, and the reaction starts. The residence time of the materials in the microchannel reactor is 13.33 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously transferred to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are transferred completely and the polymerization reaction is complete, ethanol is added to terminate the reaction in the polymerization kettle, and then 2.0 times the industrial water is added. It is washed at 55°C to remove the residual metal in the glue solution, and then added to the vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105°C to obtain liquid polybutadiene rubber.

[0069] Comparative Example 4

[0070] Compared with Example 4, the transfer rate ratio of the materials in the monomer solution storage tank and the initiator solution storage tank in Comparative Example 4 is 1.5:1.

[0071] The preset number-average molecular weight is 4000, and the monomer mass percentage is 54.0%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 41.08 g of hexane, 255.0 g of tetrahydrofuran, 52.72 g of ethyl tetrahydrofurfuryl ether, 45.45 g of potassium tert-butoxide, and 3240.0 g of butadiene are successively added to the tank. Argon is filled to pressurize to 1.2 MPa, and stirring is started for 10 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 2463.92 g of hexane and 0.81 mol of tert-butyl lithium are successively added to the tank. Argon is filled to pressurize to 1.2 MPa, and stirring is started for 10 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 25 °C and the back pressure to reach 4.0 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 90 mL / min and 60 mL / min respectively. The reaction starts. The residence time of the materials in the microchannel reactor is 13.33 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously delivered to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are delivered and the polymerization reaction is complete, ethanol is added to terminate the reaction in the polymerization kettle. Then, 2.0 times the amount of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle. It is dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0072] Table 4 Molecular weight and its distribution of Example 4 and Comparative Example 4

[0073] Preset molecular weight Number-average molecular weight of the product Molecular weight distribution Example 4 4000 4058 1.06 Comparative Example 4 4000 2394 1.45

[0074] As can be seen from Table 4, in Comparative Example 4, because the delivery rate ratio of the materials is 1.5:1, when configuring the monomer, the addition amount of the solvent is only 296.08 g. The monomer solution storage tank is mainly composed of butadiene, and gasification is likely to occur during the delivery and reaction processes, resulting in inaccurate feed amount and a large difference between the molecular weight and the preset molecular weight.

[0075] Example 5

[0076] The preset number-average molecular weight is 3000, and the monomer mass percentage is 78.0%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 342.26 g of cyclohexane, 150 g of tetrahydrofuran, 101.54 g of ethyl tetrahydrofurfuryl ether, 87.53 g of potassium tert-butoxide, and 4680.0 g of butadiene are successively added to the tank. Argon is filled to pressurize to 3.6 MPa, and stirring is started for 15 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 827.73 g of cyclohexane and 1.56 mol of sec-butyllithium are successively added to the tank. Argon is filled to pressurize to 3.6 MPa, and stirring is started for 15 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 10 °C and the back pressure to reach 6.0 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 80 mL / min and 20 mL / min respectively to start the reaction. The residence time of the materials in the microchannel reactor is 10 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously delivered to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are delivered completely and the polymerization reaction is complete, ethanol is added to terminate the reaction in the polymerization kettle, and then 2.0 times the amount of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0077] Comparative Example 5

[0078] Compared with Example 5, in Comparative Example 5, the monomer solution storage tank and the initiator solution storage tank are not pressurized and stirred for blending.

[0079] The preset number-average molecular weight is 3000, and the monomer mass percentage is 78.0%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 342.26 g of cyclohexane, 150 g of tetrahydrofuran, 101.54 g of ethyl tetrahydrofurfuryl ether, 87.53 g of potassium tert-butoxide, and 4680.0 g of butadiene are added to the tank in sequence. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 827.73 g of cyclohexane and 1.56 mol of sec-butyllithium are added to the tank in sequence. After starting the temperature control equipment and waiting for the temperature to reach 10 °C and the back pressure to reach 6.0 MPa, start the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution, with the delivery rates of 80 mL / min and 20 mL / min respectively, and start the reaction. The residence time of the materials in the microchannel reactor is 10 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously delivered to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are delivered completely and the polymerization reaction is complete, ethanol is added to terminate the reaction in the polymerization kettle, and then 2.0 times the amount of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0080] Table 5 Molecular weight and its distribution of the products in Example 5 and Comparative Example 5

[0081] Preset molecular weight Product molecular weight Molecular weight distribution Li metal content Example 5 3000 3380 1.12 2.66 ppm Comparative Example 5 3000 4058 1.51 3.12 ppm

[0082] As can be seen from Table 5, in Comparative Example 5, the monomer solvent storage tank and the initiator solution storage tank are not pressurized and blended, and the molecular weight of the prepared product is quite different from the preset molecular weight, and the molecular weight distribution is relatively wide. This is mainly because part of the monomer butadiene in the monomer solution storage tank is in a gaseous state, which will affect the feeding accuracy of the high-pressure constant-flow delivery pump and a certain pressure needs to be applied.

[0083] Example 6

[0084] The preset number-average molecular weight is 8000, and the monomer mass percentage is 55.0%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 536.73 g of cyclohexane, 260.0 g of tetrahydrofuran, 27.67 g of diethylene glycol dimethyl ether, 22.71 g of sodium tert-pentoxide, 2475.0 g of isoprene and 825.0 g of styrene are successively added into the tank. Argon is filled to pressurize to 0.01 MPa, and stirring is started for 15 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 1903.27 g of cyclohexane and 0.41 mol of sec-butyllithium are successively added into the tank. Argon is filled to pressurize to 0.01 MPa, and stirring is started for 15 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 20°C and the back pressure to reach 3.0 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 80 mL / min and 40 mL / min respectively, and the reaction starts. The residence time of the materials in the microchannel reactor is 8.33 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously delivered to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are delivered and the polymerization reaction is complete, methanol is added to terminate the reaction in the polymerization kettle, and then 2.0 times of industrial water is added. It is washed at 55°C to remove the residual metal in the glue solution, and then added to the vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105°C to obtain liquid polyisoprene-styrene rubber.

[0085] Example 7

[0086] The preset number-average molecular weight is 8000, and the monomer mass percentage is 55.0%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 363.90 g of cyclohexane, 260.0 g of tetrahydrofuran, 27.67 g of diethylene glycol dimethyl ether, 22.71 g of sodium tert-pentoxide, 3135.0 g of butadiene and 165.0 g of styrene are successively added to the tank. Argon is filled to pressurize to 0.5 MPa, and stirring is started for 15 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 2076.09 g of cyclohexane and 0.41 mol of sec-butyllithium are successively added to the tank. Argon is filled to pressurize to 0.5 MPa, and stirring is started for 15 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 20°C and the back pressure to reach 3.0 MPa, the high-pressure constant-flow transfer pumps for the monomer solution and the initiator solution are started, and the transfer rates are 100 mL / min and 50 mL / min respectively, and the reaction starts. The residence time of the materials in the microchannel reactor is 10.0 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously transferred to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are transferred completely and the polymerization reaction is complete, methanol is added to terminate the reaction in the polymerization kettle, and then 2.0 times of industrial water is added. It is washed at 55°C to remove the residual metal in the glue solution, and then added to the vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105°C to obtain liquid styrene-butadiene rubber.

[0087] Example 8

[0088] The preset number average molecular weight is 8000, and the monomer mass percentage is 55.0%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 405.59 g of cyclohexane, 260.0 g of tetrahydrofuran, 27.67 g of diethylene glycol dimethyl ether, 22.71 g of sodium tert-pentoxide, 2805.0 g of butadiene, and 495.0 g of styrene are successively added to the tank. Argon is filled to pressurize to 1.0 MPa, and stirring is started for 15 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 2034.44 g of cyclohexane and 0.41 mol of sec-butyllithium are successively added to the tank. Argon is filled to pressurize to 1.0 MPa, and stirring is started for 15 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 20 °C and the back pressure to reach 3.0 MPa, the high-pressure constant flow transfer pumps for the monomer solution and the initiator solution are started, and the transfer rates are 90 mL / min and 45 mL / min respectively, and the reaction starts. The residence time of the materials in the microchannel reactor is 11.1 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously transferred to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are transferred completely and the polymerization reaction is complete, methanol is added to terminate the reaction in the polymerization kettle, and then 2.5 times of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene-styrene rubber.

[0089] Example 9

[0090] The preset number-average molecular weight is 8000, and the monomer mass percentage is 55.0%. Argon is introduced into the monomer solution storage tank for replacement three times. 447.22 g of cyclohexane, 260.0 g of tetrahydrofuran, 27.67 g of diethylene glycol dimethyl ether, 22.71 g of sodium tert-pentoxide, 2475.0 g of butadiene and 825.0 g of styrene are successively added into the tank. Argon is filled and pressurized to 2.0 MPa, and stirring is started for 15 min to make the materials mix evenly; Argon is introduced into the initiator solution storage tank for replacement three times. 1992.78 g of cyclohexane and 0.41 mol of sec-butyllithium are successively added into the tank. Argon is filled and pressurized to 2.0 MPa, and stirring is started for 15 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 20 °C and the back pressure to reach 3.5 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 120 mL / min and 60 mL / min respectively, and the reaction starts. The residence time of the materials in the microchannel reactor is 13.88 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously delivered to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are delivered and the polymerization reaction is complete, methanol is added to terminate the reaction in the polymerization kettle, and then 2.5 times of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid styrene-butadiene rubber.

[0091] Table 6 Product structure composition, molecular weight and its distribution of Examples 6-9

[0092] Preset molecular weight Combined styrene content Product molecular weight Molecular weight and its distribution Example 6 8000 25.11％ 8144 1.13 Example 7 8000 5.09％ 8216 1.16 Example 8 8000 14.96％ 8159 1.09 Example 9 8000 25.20％ 8241 1.14

[0093] As can be seen from Table 6, by regulating the monomer ratio, liquid styrene-isoprene rubber and liquid styrene-butadiene rubber with different styrene contents are prepared by the method of the present invention.

[0094] Example 10

[0095] The preset number-average molecular weight is 3000, and the monomer mass percentage is 50.0%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 1773.56 g of n-heptane, 300.0 g of diethyl ether, 65.09 g of ethyl tetrahydrofurfuryl ether, 56.11 g of potassium tert-butoxide, and 3000.0 g of butadiene are successively added to the tank. Argon is filled to pressurize to 2.0 MPa, and stirring is started for 15 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 926.44 g of n-heptane and 1.0 mol of sec-butyllithium are successively added to the tank. Argon is filled to pressurize to 2.0 MPa, and stirring is started for 15 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 20 °C and the back pressure to reach 3.5 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 120 mL / min and 30 mL / min respectively. The reaction starts, and the residence time of the materials in the microchannel reactor is 10.0 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously delivered to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are delivered and the polymerization reaction is complete, methanol is added to terminate the reaction in the polymerization kettle, and then 2.5 times the industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle. It is dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0096] Comparative Example 6

[0097] Compared with Example 10, in Comparative Example 6, traditional batch polymerization is used. The types and dosages of materials such as monomers, initiators, regulators, and solvents are the same as those in Example 10. The difference is only that the materials are not fed continuously, but the monomers, initiators, regulators, and solvents are all added at once.

[0098] The preset number-average molecular weight is 3000, and the monomer mass percentage is 50.0%. First, argon is introduced to replace the polymerization kettle three times. Then, 2700.0 g of n-heptane, 300.0 g of diethyl ether, 65.09 g of ethyl tetrahydrofurfuryl ether, 56.11 g of potassium tert-butoxide, and 3000.0 g of butadiene are successively added to the polymerization kettle. 1.0 mol of sec-butyllithium is added at 20 °C. After the polymerization reaction is complete, methanol is added to terminate the reaction in the polymerization kettle, and industrial water 2.5 times the volume of the glue solution is added for washing. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle. It is dried for 5 hours under the conditions of a vacuum degree of -0.06 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0099] Table 7 Molecular weight, its distribution, and temperature change of Example 10 and Comparative Example 6

[0100] Preset molecular weight Number-average molecular weight of the product Molecular weight distribution Temperature change Example 10 3000 3202 1.12 20～22℃ Comparative Example 6 3000 3208 2.30 20～80℃

[0101] As can be seen from Table 7, the molecular weight of the liquid polybutadiene rubber prepared by the method of the present invention is equivalent to the preset theoretical molecular weight, and during the polymerization reaction process, the change in the polymerization reaction temperature is small. Comparative Example 6 uses traditional batch polymerization. When the monomer concentration is 50.0%, the change in the polymerization reaction temperature is large and cannot be effectively controlled, and the molecular weight distribution of the prepared liquid polybutadiene rubber is wide, mainly because the amount of initiator added is large, and the mixing effect of the traditional batch polymerization materials is worse than that of the microchannel reactor, so the molecular weight distribution is wide.

[0102] Example 11

[0103] The preset number-average molecular weight is 4000, the monomer mass percentage is 60.0%. Argon is introduced into the monomer solution storage tank for 3 replacements. 1112.01 g of n-octane, 300.0 g of diethyl ether, 58.58 g of ethyl tetrahydrofurfuryl ether, 50.50 g of potassium tert-butoxide and 3600.0 g of butadiene are successively added to the tank. Argon is charged to a pressure of 1.5 MPa, and stirring is started for 15 min to make the materials mix evenly; Argon is introduced into the initiator solution storage tank for 3 replacements. 987.99 g of n-octane and 0.9 mol of tert-butyllithium are successively added to the tank. Argon is charged to a pressure of 1.5 MPa, and stirring is started for 15 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 20 °C and the back pressure to reach 3.5 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 120 mL / min and 30 mL / min respectively, and the reaction starts. The residence time of the materials in the microchannel reactor is 10.0 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously transported to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are transported and the polymerization reaction is complete, ethanol is added to terminate in the polymerization kettle, and then 2.5 times of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to a vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0104] Example 12

[0105] The preset number-average molecular weight is 4000, and the monomer mass percentage is 60.0%. Argon is introduced into the monomer solution storage tank for replacement three times. Then, 1112.01 g of n-octane, 300.0 g of diethyl ether, 58.58 g of ethyl tetrahydrofurfuryl ether, 50.50 g of potassium tert-butoxide, and 3600.0 g of butadiene are successively added to the tank. Argon is filled to pressurize to 1.5 MPa, and stirring is started for 15 min to make the materials mix evenly. Argon is introduced into the initiator solution storage tank for replacement three times. Then, 987.99 g of n-octane and 0.9 mol of tert-butyllithium are successively added to the tank. Argon is filled to pressurize to 1.5 MPa, and stirring is started for 15 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 40 °C and the back pressure to reach 3.5 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 120 mL / min and 30 mL / min respectively, and the reaction starts. The residence time of the materials in the microchannel reactor is 10.0 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously delivered to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are delivered and the polymerization reaction is complete, ethanol is added to terminate the reaction in the polymerization kettle, and then 2.5 times of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle and dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0106] Example 13

[0107] The preset number-average molecular weight is 4000, and the monomer mass percentage is 60.0%. Argon is introduced into the monomer solution storage tank for replacement three times. 1112.01 g of n-octane, 300.0 g of diethyl ether, 58.58 g of ethyl tetrahydrofurfuryl ether, 50.50 g of potassium tert-butoxide and 3600.0 g of butadiene are successively added into the tank. Argon is filled to pressurize to 1.5 MPa, and stirring is started for 15 min to make the materials mix evenly; Argon is introduced into the initiator solution storage tank for replacement three times. 987.99 g of n-octane and 0.9 mol of tert-butyl lithium are successively added into the tank. Argon is filled to pressurize to 1.5 MPa, and stirring is started for 15 min to make the materials mix evenly. After starting the temperature control equipment and waiting for the temperature to reach 60 °C and the back pressure to reach 3.5 MPa, the high-pressure constant-flow delivery pumps for the monomer solution and the initiator solution are started, and the delivery rates are 120 mL / min and 30 mL / min respectively. The reaction starts, and the residence time of the materials in the microchannel reactor is 10.0 min. During the reaction process, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously delivered to the microchannel reactor for reaction. After the materials in the monomer solution storage tank and the initiator solution storage tank are delivered and the polymerization reaction is complete, ethanol is added to terminate in the polymerization kettle, and then 2.5 times of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle. It is dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0108] Comparative Example 7

[0109] Compared with Example 12, in Comparative Example 7, liquid polybutadiene rubber was prepared by traditional batch polymerization. The types and amounts of materials such as monomers, initiators, regulators, and solvents were the same as those in Example 12. The difference was only that the materials were not fed continuously, but the monomers, initiators, regulators, and solvents were all added at once.

[0110] The preset number-average molecular weight is 4000, and the monomer mass percentage is 60.0%. First, argon is introduced to replace the polymerization kettle three times. 2100 g of n-octane, 300 g of diethyl ether, 58.58 g of ethyl tetrahydrofurfuryl ether, 50.50 g of potassium tert-butoxide and 3600.0 g of butadiene are successively added into the polymerization kettle. 0.9 mol of tert-butyl lithium is added at 40 °C. After the polymerization reaction is complete, ethanol is added to terminate in the polymerization kettle, and then 2.5 times of industrial water is added. It is washed at 55 °C to remove the residual metal in the glue solution, and then added to the vacuum kettle. It is dried for 5 hours under the conditions of a vacuum degree of -0.08 MPa and a temperature of 105 °C to obtain liquid polybutadiene rubber.

[0111] Table 8 Microstructure, molecular weight and its distribution of the products of Examples 11 - 13 and Comparative Example 7

[0112] Preset molecular weight Product molecular weight Molecular weight distribution Vinyl content Reaction temperature Example 11 4000 4131 1.09 95.21％ 20～22.1℃ Example 12 4000 4156 1.11 82.36％ 40～42.6℃ Example 13 4000 4206 1.08 68.62％ 60～63℃ Comparative Example 7 4000 4122 1.42 51.23％ 40～80℃

[0113] As can be seen from Table 8, by controlling the polymerization reaction temperature, liquid polybutadiene rubbers with different vinyl structure contents were prepared using the device of the present invention. The molecular weight of the liquid polybutadiene rubber prepared by the method of the present invention is equivalent to the preset theoretical molecular weight, and during the polymerization reaction process, the change in the polymerization reaction temperature is small. Comparative Example 7 used traditional autoclave polymerization. With the same dosage of the structure regulator, the vinyl structure was 51.23%. This is mainly because the temperature of the polymerization kettle is difficult to control, and the high temperature causes the reduction of the vinyl structure content, and the molecular weight distribution of the prepared liquid polybutadiene rubber is relatively wide.

[0114] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a diene liquid rubber, characterized in that: The following steps are involved: (1) nitrogen or argon is introduced into the monomer solution storage tank for replacement, and organic solvent, regulator and monomer are added into the tank in sequence, pressurized, and stirred to mix the materials evenly; (2) nitrogen or argon is introduced into the initiator solution storage tank for replacement, and a non-polar solvent and an initiator are added to the tank in sequence, pressurized, and stirred to mix the materials evenly; (3) The materials in the monomer solution storage tank and the initiator solution storage tank are not added all at once, but are added in a continuous feeding manner during the reaction process, specifically including: after the temperature of the microchannel reactor is controlled to the polymerization temperature and back pressure is applied, the materials in the monomer solution storage tank and the initiator solution storage tank are continuously transported to the microchannel reactor for mixing and starting the reaction; after the reaction starts, the materials in the monomer solution storage tank and the initiator solution storage tank are still continuously transported to the microchannel reactor for reaction; after the materials in the monomer solution storage tank and the initiator solution storage tank are transported and the polymerization reaction is complete, a terminator is added to the polymerization kettle to terminate the reaction; (4) washing to remove residual metals and vacuum drying to obtain a diene liquid rubber; The mass of the monomer accounts for 50% to 80% of the total mass of the material.

2. The preparation method according to claim 1, characterized in that: The back pressure is 2.0-8.0 MPa.

3. The preparation method according to claim 1, characterized in that: In step (1), the organic solvent is a composite of a polar solvent and a non-polar solvent.

4. The preparation method according to claim 3, characterized in that: In step (1), the polar solvent is at least one of diethyl ether, dioxane, tetrahydrofuran, and dimethoxyethane; In step (1) or step (2), the non-polar solvent is at least one of hexane, cyclohexane, n-heptane, and n-octane; The mass ratio of the polar solvent in step (1) to the sum of the non-polar solvents in step (1) and step (2) is 0.1 to 0.3:

1.

5. The preparation method according to claim 1, characterized in that: The regulator is a compound of a Lewis base polarity regulator and a Lewis acid polarity regulator, and the molar ratio of the Lewis base polarity regulator to the Lewis acid polarity regulator is 1:1-3.

6. The preparation method according to claim 1, characterized in that: The Lewis base polarity regulator is one of tetramethylethylenediamine, diethylene glycol dimethyl ether, ethyltetrahydrofurfuryl ether, hexyltetrahydrofurfuryl ether, and distetrahydrofurfuryl propane; the Lewis acid polarity regulator is one of potassium tert-butoxide, sodium tert-amyl alcohol, sodium menthol, and sodium dodecylbenzene sulfonate.

7. The preparation method according to claim 1, characterized in that: The monomer is at least one of butadiene, isoprene, styrene and myrcene.

8. The preparation method according to claim 1, characterized in that: The initiator is one of sec-butyl lithium and tert-butyl lithium.

9. The preparation method according to claim 1, characterized in that: The terminator is one of deionized water and C1-C6 alcohol.

10. The preparation method according to claim 1, characterized in that: The pressure of the monomer solution storage tank and the initiator solution storage tank is 0.01-4 MPa.

11. The preparation method according to claim 1, characterized in that: The material delivery rate of the monomer solution storage tank and the initiator solution storage tank is 2 mL / min to 150 mL / min, and the delivery ratio is 2 to 4:

1.

12. The preparation method according to claim 1, characterized in that: The reaction temperature is 10-60°C.

13. The preparation method according to claim 1, characterized in that: The molar ratio of the regulator to the initiator is 1 to 3:

1.

14. The preparation method according to claim 1, characterized in that: The mass of the monomer accounts for 55% to 70% of the total mass of the material.

15. The preparation method according to claim 1, characterized in that: The residence time of the material in the microchannel reactor is 4 minutes to 18 minutes.

16. The preparation method according to claim 1, characterized in that: The temperature of the vacuum drying is 95-120° C., and the vacuum degree is -0.06-0.09 MPa.

17. The preparation method according to claim 1, characterized in that: The microchannel reactor has a liquid holding capacity of 50 to 5000 mL and is provided with multiple material outlets.

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