Pipeline continuous synthesis method of polyvinyl siloxane microspheres and used device

Abstract

The invention belongs to the technical field of chemical production, and particularly relates to a channelized continuous synthesis method of polyvinyl siloxane microspheres and a used device. The continuous channelization device comprises a channelization reactor I and a channelization reactor II, the channelization reactor I and the channelization reactor II are both multi-side-line feeding tubular reactors. The invention also provides a channelized continuous synthesis method of the polyvinyl siloxane microspheres. The method comprises the following steps: carrying out hydrolysis reaction on vinyltrimethoxysilane and a hydrochloric acid solution in a channelized reactor I; primary reaction liquid flowing out of the channelization reactor I and aqueous alkali are subjected to condensation polymerization in a channelization reactor II; the ultimate reaction liquid flowing out of the channelization reactor II enters a collecting tank and is subjected to post-treatment, and the polyvinyl siloxane microspheres are obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and in particular relates to a pipeline continuous synthesis method of polyvinylsiloxane microspheres and a device used therein. Background Art

[0002] Vinyl siloxane microspheres have -Si-O-Si- bonds as their main chain, with vinyl groups directly connected to silicon atoms. This unique chemical structure enables them to have the excellent properties of both organic and inorganic materials, showing excellent heat resistance, aging resistance, electrical insulation, flame retardancy and hydrophobicity. They are now widely used in cosmetics, catalyst carriers, rubber, plastics, coatings, biomedicine and other fields.

[0003] Patent CN201210019431.3 uses a base-catalyzed sol-gel method under nitrogen conditions to prepare monodisperse micron-sized polysilicon microspheres. The method provided by the invention has complex processes, harsh reaction conditions, and low utilization of silane monomers, which is not conducive to the industrial production of silicon microspheres.

[0004] Patent CN116688891A combines reverse suspension polymerization with sol-gel phase separation to prepare organosilicon microspheres with a particle size ranging from 1 μm to 50 μm. The method provided by the invention is simple, but the particle size distribution of the microspheres is relatively wide.

[0005] Patent CN113881050A obtains organosilicon microspheres by hydrolysis and polycondensation under base catalysis. The method provided by the invention is simple, but it is necessary to control the concentration of the precursor to ensure the monodispersity of the silicon microspheres, so a large amount of solvent is required in the preparation process. The above-mentioned methods all use a reactor to prepare organosilicon microspheres, which is an intermittent reaction and has low production efficiency. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for continuously preparing organosilicon microspheres and a corresponding device, which can realize continuous and stable production and improve production efficiency.

[0007] In order to solve the above technical problems, the present invention provides a continuous pipeline device for preparing polyvinylsiloxane microspheres, comprising a pipeline reactor I and a pipeline reactor II; the pipeline reactor I and the pipeline reactor II are both multi-side line feeding tubular reactors;

[0008] The outlet of the vinyltrimethoxysilane raw material tank is connected to the main inlet of the pipeline reactor 1 through a pipeline with a stop valve and a pump 1;

[0009] The outlet of the acid solution raw material tank is connected to the pump II through a pipeline provided with a stop valve, and then connected to the main inlet of the pipeline reactor I and the side line inlet of the pipeline reactor I through the pump II;

[0010] A back pressure valve I and a one-way valve are arranged at the outlet of the pipeline reactor I. The outlet of the pipeline reactor I is connected to the main inlet of the pipeline reactor II through the back pressure valve I and the one-way valve. The one-way valve is used to prevent the backflow of materials. The back pressure valve I is used to control the reaction pressure of the pipeline reactor I.

[0011] The alkali solution raw material tank is connected to pump III through a pipeline with a stop valve, and then connected to the main inlet of pipeline reactor II and the side line inlet of pipeline reactor II through pump III;

[0012] A back pressure valve II is arranged at the outlet of the pipeline reactor II, and the outlet of the pipeline reactor II is connected to the inlet of the collecting tank through the back pressure valve II; the back pressure valve II is used to control the reaction pressure of the pipeline reactor II.

[0013] As an improvement of the continuous pipeline device for preparing polyvinylsiloxane microspheres of the present invention: the outlet of the collecting tank is connected to the outlet of the reaction liquid through a pipeline with a stop valve.

[0014] As a further improvement of the continuous pipeline device for preparing polyvinylsiloxane microspheres of the present invention:

[0015] The pipeline reactor I has 7 to 9 side line inlets, which are evenly located at different pipe lengths of the pipeline reactor I; the main inlet of the pipeline reactor I is located at the beginning of the pipeline reactor I; a pump II is provided at the main inlet and each side line inlet of the pipeline reactor I, a check valve is provided on the pipeline before each side line inlet, and a static mixer is provided on the pipeline after the main inlet and each side line inlet; the outlet of the acid solution raw material tank is connected to the main inlet of the pipeline reactor I and the side line inlet of the pipeline reactor I through the corresponding pump II;

[0016] There are 7 to 9 side line inlets of the pipeline reactor II, which are located at different pipe lengths of the pipeline reactor II; the main inlet of the pipeline reactor II is located at the beginning of the pipeline reactor II, and a pump III is respectively provided at the main inlet and each side line inlet of the pipeline reactor II; a check valve is provided on the pipeline before each side line inlet, and a static mixer is provided on the pipeline after the main inlet and each side line inlet; the outlet of the alkaline solution raw material tank is connected to the main inlet of the pipeline reactor II and the side line inlet of the pipeline reactor II through the corresponding pump III.

[0017] As a further improvement of the continuous pipeline device for preparing polyvinylsiloxane microspheres of the present invention:

[0018] The pipeline reactor I is provided with 7 side line inlets, namely, side line 1 to side line 7; the 7 side line inlets, namely, side line 1 to side line 7, are respectively located at 1 / 14, 3 / 14, 5 / 14, 7 / 14, 9 / 14, 11 / 14, and 13 / 14 of the length of the pipeline reactor I;

[0019] The pipeline reactor II is provided with seven side line inlets, namely, side line 1 to side line 7; the seven side line inlets, namely, side line 1 to side line 7, are respectively located at 1 / 14, 3 / 14, 5 / 14, 7 / 14, 9 / 14, 11 / 14 and 13 / 14 of the length of the pipeline reactor II.

[0020] As a further improvement of the continuous pipeline device for preparing polyvinylsiloxane microspheres of the present invention:

[0021] The inner wall of the pipeline of the pipeline reactor I is provided with baffles, and the adjacent baffles are arranged alternately on the left and right sides. The angle a between each baffle and the inner wall of the pipeline is 25-31°, and the distance between the baffles (straight-line distance) is 0.5-1m. The function of the baffles is to make the mixed solution in the pipeline in a turbulent state;

[0022] The inner wall of the pipeline in the pipeline reactor II is provided with baffles, and the adjacent baffles are arranged alternately on the left and right sides. The angle b between each baffle and the inner wall of the pipeline is 5-8°, and the distance between the baffles is 1-2m. The function of the baffles is to maintain a slightly disturbed state of the solution in the pipeline.

[0023] As a further improvement of the continuous pipeline device for preparing polyvinylsiloxane microspheres of the present invention:

[0024] The vinyltrimethoxysilane raw material tank, the acid solution raw material tank, and the alkali solution raw material tank are each provided with a pressure gauge.

[0025] The present invention also provides a pipeline continuous synthesis method of polyvinylsiloxane microspheres, comprising the following steps:

[0026] 1) Hydrolysis:

[0027] Set the feed volume ratio of vinyltrimethoxysilane: hydrochloric acid solution = 1:2-12 (preferably 1:4-6),

[0028] Vinyltrimethoxysilane is pumped into the pipeline reactor I from the main inlet of the pipeline reactor I, and the acid solution is pumped into the pipeline reactor I from the main inlet and the side line inlet of the pipeline reactor I, and a hydrolysis reaction is carried out in the pipeline reactor I, with a temperature of 25 to 50° C. (preferably 30 to 40° C.), a reaction pressure of 1.5 to 3 MPa (preferably 1.5 to 2 MPa), and a reaction time of 10 to 30 min (preferably 10 to 20 min);

[0029] The reaction formula of this step is:

[0030]

[0031] 2) Polycondensation:

[0032] The volume ratio of the alkaline solution to the acid solution in step 1) is set to 1:20-30;

[0033] The primary reaction liquid (i.e., the reaction product silanol) flowing out of the pipeline reactor I is pumped into the pipeline reactor II from the main inlet of the pipeline reactor II, and the alkaline solution is pumped into the pipeline reactor II from the main inlet and the side line inlet of the pipeline reactor II, and a polycondensation reaction is carried out in the pipeline reactor II, with a reaction temperature of 25 to 55° C. (preferably 35 to 55° C.), a reaction pressure of 1.2 to 2.6 MPa (preferably 1.2 to 1.6 MPa), and a reaction time of 8 to 15 min (preferably 8 to 12 min);

[0034] The reaction formula of this step is:

[0035]

[0036] 3) The final reaction liquid flowing out of the pipeline reactor II enters a collection tank and is post-processed to obtain polyvinylsiloxane microspheres.

[0037] As an improvement of the pipeline continuous synthesis method of polyvinyl siloxane microspheres of the present invention: the post-treatment of step 3) is: the reaction product flowing out of the pipeline reactor II is centrifuged, dried, and crushed to obtain polyvinyl siloxane microspheres.

[0038] As an improvement of the pipeline continuous synthesis method of polyvinylsiloxane microspheres of the present invention: the acid solution is a hydrochloric acid solution with a pH of 3.5 to 4.5 (preferably pH = 4).

[0039] The alkaline solution is (0.1±0.01) mol / L NaOH solution.

[0040] As an improvement of the pipeline continuous synthesis method of polyvinylsiloxane microspheres of the present invention:

[0041] The inner diameter (diameter) of the pipeline reactor I is 3 to 20 mm, and the length of the tube is about 50 to 170 m;

[0042] The inner diameter of the pipeline reactor II is 8 to 30 mm, and the length of the tube is about 30 to 150 m.

[0043] The process route of the present invention is as follows: the present invention uses vinyl trimethoxysilane and an acid solution as starting materials, and prepares polyvinyl siloxane microspheres through two-step reactions of hydrolysis and polycondensation; that is, the present invention uses vinyl trimethoxysilane and an acid solution as starting materials, completes the hydrolysis reaction of vinyl trimethoxysilane and the acid solution through a pipeline reactor I, and then completes the polycondensation reaction through a pipeline reactor II, collects and obtains a crude polyvinyl siloxane microsphere, and the product yield is between 85% and 99%. Then, after centrifugation, drying, and pulverization, a polyvinyl siloxane microsphere product is obtained.

[0044] In summary, the method for preparing polyvinyl siloxane microspheres of the present invention has the following technical advantages:

[0045] Most of the existing organosilicon microspheres are prepared by intermittent method, while the present invention adopts continuous method to directly prepare them, thereby improving production efficiency.

[0046] The present invention applies a pipeline reactor to the production process of preparing polyvinyl siloxane microspheres by acid-base two-step catalysis. Since vinyl trimethoxy silane, acid and alkali solutions are fed in multiple side lines, the pipeline reactor can not only maintain a high concentration of vinyl trimethoxy silane in the system and accelerate the reaction, but also control the pH value in the system and reduce the occurrence of side reactions, thereby greatly improving the production efficiency of polyvinyl siloxane microspheres. The microspheres have regular morphology and narrow particle size distribution.

[0047] The present invention provides static mixers at the feed inlet and the side feed inlet of the pipeline reactor, so that the materials can be quickly mixed and evenly, the mass transfer efficiency is high, the side reactions caused by poor mass transfer can be reduced, and the selectivity of the reaction can be improved. Compared with the conventional kettle reactor, no dynamic equipment such as a stirrer is required, which is not only beneficial to reducing energy consumption and reducing production costs, but also beneficial to the sealing of the reactor and improving production safety.

[0048] The pipeline reactor of the present invention can accurately control the temperature, and the heat released by the first step hydrolysis reaction is recovered for use in the second step polycondensation reaction, thereby improving the safety of the reaction process and reducing the investment in equipment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0050] Figure 1 This is a schematic diagram of the structure of the device for preparing polyvinylsiloxane microspheres.

[0051] Figure 2 for Figure 1 Schematic diagram of the structure of the tubular reactor I.

[0052] Figure 3 for Figure 1 Schematic diagram of the structure of the tubular reactor II.

[0053] Figure 4 This is the particle size distribution diagram of Example 1-1.

[0054] Figure 5 This is the particle size distribution diagram of Example 1-2.

[0055] Figure 6 This is the electron microscope image of Example 1-1. DETAILED DESCRIPTION

[0056] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0057] Device Example 1: A continuous pipeline device for preparing polyvinylsiloxane microspheres, the structure of which is as follows: Figure 1 As shown, it includes a pipeline reactor I and a pipeline reactor II;

[0058] Pipeline reactor I, such as Figure 2 As shown, the inlet of the pipeline reactor I includes a main inlet and seven side line inlets, namely, side line 1 to side line 7; the main inlet is located at the beginning of the pipeline reactor I, and the seven side line inlets, namely, side line 1 to side line 7, are located at 1 / 14, 3 / 14, 5 / 14, 7 / 14, 9 / 14, 11 / 14, and 13 / 14 of the length of the pipeline reactor I, respectively; the main inlet and the seven side line inlets, namely, side line 1 to side line 7, are each provided with a corresponding pump II, that is, the number of pumps II is 8. A check valve is provided on the pipeline before each side line inlet, a static mixer is provided on the pipeline after the main inlet and each side line inlet, and a back pressure valve I and a one-way valve are provided at the outlet of the pipeline reactor I (i.e., at the rear end of the last reaction section), and the back pressure valve I is used to control the reaction pressure of the pipeline reactor I; the function of the one-way valve is to prevent the material from flowing back.

[0059] The inner wall of the pipeline of the pipeline reactor I is provided with baffles, and adjacent baffles are arranged alternately on the left and right sides. For the clarity of the drawing, Figure 2 Only two adjacent baffles are shown. The angle a between each baffle and the inner wall of the pipe is 25°, and the distance between each baffle (straight line distance) is 0.75 m, so that the mixed solution is in a turbulent state in the pipe.

[0060] The outlet of the vinyltrimethoxysilane raw material tank is connected to the main inlet of the pipeline reactor I through a pipeline with a stop valve 1, a pump 1, a pipeline with a stop valve 3, and a pipeline with a stop valve 5 in sequence; a pressure gauge P is provided on the vinyltrimethoxysilane raw material tank.

[0061] The outlet of the acid solution raw material tank is connected to 8 pumps II through a pipeline with a stop valve 2, one of which is connected to the main inlet of the pipeline reactor I through a pipeline with a stop valve 4 and a pipeline with a stop valve 5 in turn, and the other 7 pumps II are connected to the corresponding 7 side line inlets of the side line 1 to the side line 7 on the pipeline reactor I through corresponding pipelines with stop valves; the acid solution raw material tank is provided with a pressure gauge P. For the clarity of the drawing, Figure 2 In the figure, the stop valve is omitted.

[0062] Pipeline reactor II, such as Figure 3 As shown, the inlet of the pipeline reactor II includes the main inlet and 7 side line inlets, namely, side line 1 to side line 7; the main inlet is located at the beginning of the pipeline reactor II, and the side lines 1 to side lines 7 are respectively located at 1 / 14, 3 / 14, 5 / 14, 7 / 14, 9 / 14, 11 / 14, and 13 / 14 of the length of the pipeline reactor II; the main inlet and the 7 side line inlets, namely, the side line 1 to side line 7, are each provided with a corresponding pump III, that is, the number of pumps III is 8. A check valve is provided on the pipeline before each side line inlet, a static mixer is provided on the pipeline after the main inlet and each side line inlet, and a back pressure valve II is provided at the outlet of the pipeline reactor II (i.e., at the rear end of the last reaction section), and the back pressure valve II is used to control the reaction pressure of the pipeline reactor II.

[0063] The inner wall of the pipeline inside the pipeline reactor II is provided with baffles, and adjacent baffles are arranged alternately on the left and right sides. For the clarity of the drawing, Figure 3 Only two adjacent baffles are shown in the figure. The angle b between each baffle and the pipeline is 5°, and the distance between each baffle is 1.5m, so that the solution maintains a slightly disturbed state in the pipeline.

[0064] The alkali solution raw material tank is connected to 8 pumps III through a pipeline with a stop valve 6, one of which is connected to the main inlet of the pipeline reactor II through a pipeline with a stop valve 7; the other 7 pumps II are connected to the 7 side line inlets of the pipeline reactor II through corresponding pipelines with stop valves. The alkali solution raw material tank is equipped with a pressure gauge P. For the clarity of the drawing, Figure 3 In the figure, the stop valve is omitted.

[0065] The outlet of the pipeline reactor I is connected to the main inlet of the pipeline reactor II through a back pressure valve I and a one-way valve; the outlet of the pipeline reactor II is connected to the inlet of the collecting tank through a back pressure valve II, and the outlet of the collecting tank is connected to the outlet of the reaction liquid through a pipeline with a stop valve 8.

[0066] In actual operation, pumps I and II are started first, and then pump III is started when the primary reaction liquid flows out of the outlet of the pipeline reactor I. The obtained product is located in the collection tank, and the stop valve 8 can be opened later to realize the discharge.

[0067] Vinyl trimethoxysilane and acid solution are transported to pipeline reactor I for reaction under the action of pump I and pump II respectively; the reaction formula is:

[0068]

[0069] The primary reaction liquid flowing out of the pipeline reactor I flows into the pipeline reactor II after passing through the back pressure valve I and the one-way valve. The alkaline solution is transported to the pipeline reactor II under the action of the pump III. Therefore, the primary reaction liquid flowing out of the pipeline reactor I reacts with the alkaline solution in the pipeline reactor II. The reaction formula is:

[0070]

[0071] The final reaction liquid flowing out of the pipeline reactor II flows into a collection tank, and is then centrifuged, dried, and crushed to obtain the product polyvinylsiloxane microspheres.

[0072] The products obtained in the following cases were verified by conventional infrared spectroscopy and were indeed polyvinylsiloxane microspheres.

[0073] Example 1-1, a method for preparing polyvinylsiloxane microspheres, comprising the following steps:

[0074] The inner diameter of the pipeline reactor I is 8 mm, and the inner diameter of the pipeline reactor II is 15 mm. The acid solution material is a hydrochloric acid solution with a pH of 4, and the alkaline solution is a 0.1 mol / L NaOH solution.

[0075] Vinyltrimethoxysilane was added at 300 mL / min (0.018 m 3 / h) was pumped into the pipeline reactor I through pump I, and the flow rates of the main inlet and the 7 side line inlets of the acid solution material were both 225 mL / min, that is, the acid solution material entered the pipeline reactor I through the main inlet of the pipeline reactor I and the 7 side line inlets of the side line 1 to the side line 7 on the pipeline reactor I through 8 pumps II at a flow rate of 225 mL / min. The reaction temperature was 30° C., the reaction residence time of vinyltrimethoxysilane in the pipeline reactor I was about 10 minutes, and the pressure in the pipeline reactor I was stabilized at 1.5 MPa by controlling the back pressure valve I after the pipeline reactor I.

[0076] The primary reaction liquid flowing out of the pipeline reactor I flows through the one-way valve at a flow rate of 1766 mL / min and then flows into the pipeline reactor II through the main inlet of the pipeline reactor II. The flow rates of the main inlet and the 7 side line inlets of the alkaline solution material are both 7.5 mL / min, that is, the alkaline solution material enters the pipeline reactor II through the main inlet of the pipeline reactor II and the 7 side line inlets of the side line 1 to the side line 7 on the pipeline reactor II through 8 pumps III at a flow rate of 7.5 mL / min. The reaction temperature is 35°C, the reaction residence time of the primary reaction liquid in the pipeline reactor II is 10 minutes, and the pressure in the pipeline reactor II is stabilized at 1.2 MPa by controlling the back pressure valve II after the pipeline reactor II. Finally, the reaction liquid flowing out of the outlet of the pipeline reactor II flows into the collection tank, and the solid obtained by centrifugation (at a speed of 8000 for 3 minutes) is dried (dried at a temperature of 80°C for 10 hours) and crushed to obtain a polyvinylsiloxane microsphere product.

[0077] The lengths of the two pipeline reactors can be calculated by the reaction residence time and the flow rate. For example, the length of pipeline reactor I is about 58 m; the length of pipeline reactor II is about 100 m.

[0078] When the amounts of vinyltrimethoxysilane and acid solution were 5 mL and 30 mL, respectively, 2.541 g of polyvinylsiloxane microspheres were obtained. The calculation formula for the yield of polyvinylsiloxane microspheres was:

[0079]

[0080] Wherein m is the mass of polyvinylsiloxane microspheres, m1 is the mass of vinyltrimethoxysilane, and m2 is the demethylation mass (the mass of vinyltrimethoxysilane without three methoxy groups).

[0081] Examples 1-2 to 1-6

[0082] Compared with Example-1, the reaction temperature of pipeline reactors I and II was changed, and the rest was the same as Example 1-1; the product yield and particle size were tested, and the data in Table 1 were obtained.

[0083] Table 1. Effect of reaction temperature on the yield and particle size of polyvinylsiloxane microspheres

[0084]

[0085]

[0086] Examples 2-1 to 2-4

[0087] Compared with Example 1-1, the lengths of the pipeline reactor I and the pipeline reactor II were changed, thereby changing the residence time of the reaction accordingly, and the other conditions were the same as those of Example 1-1. The product yield and particle size were tested, and the data in Table 2 were obtained.

[0088] Table 2. Effect of reaction residence time on yield and particle size of polyvinylsiloxane microspheres

[0089]

[0090] Example 3 series

[0091] Compared with Example 1-1, the internal baffle angles of pipeline reactor I and pipeline reactor II were changed, and the rest were the same as Example 1-1. Thus, corresponding Examples 3-1 to 3-3 were obtained. The product yield and particle size were tested, and the data in Table 3 were obtained.

[0092] Table 3. Effect of internal baffle angle on yield and particle size of polyvinylsiloxane microspheres

[0093]

[0094]

[0095] Example 4 series

[0096] Compared with Example 1-1, the reaction pressure was changed by adjusting the back pressure valves after pipeline reactor I and pipeline reactor II, and the rest was the same as Example 1-1. The product yield and particle size were tested, and the data in Table 4 were obtained.

[0097] Table 4. Effect of reaction pressure on yield and particle size of polyvinylsiloxane microspheres

[0098]

[0099] The particle size distribution of the above-mentioned embodiment is 1 μm to 5 μm.

[0100] Comparative Example 1 Series

[0101] Compared with Example 1-1, the volumes of vinyltrimethoxysilane, acid solution, and alkaline solution were changed, and the rest was the same as Example 1-1, thereby obtaining Comparative Examples 1-1 and Comparative Examples 1-2. The product yield and particle size were tested, and the data in Table 5 were obtained.

[0102] Table 5. Effect of material volume on yield and particle size of polyvinylsiloxane microspheres

[0103]

[0104] Comparative Example 2 Series

[0105] Compared with Example 1-1, the internal baffle angles of pipeline reactor I and pipeline reactor II were changed, and the rest were the same as Example 1-1. Thus, Comparative Examples 2-1 and Comparative Examples 2-3 were obtained. The product yield and particle size were tested, and the data in Table 6 were obtained.

[0106] Table 6. Effect of internal baffle angle on yield and particle size of polyvinylsiloxane microspheres

[0107]

[0108] Comparative Example 3: Compared with Example 1-1, all side feeds were cancelled and all were fed from the main feed port, that is, the specific parameters were as follows:

[0109] Vinyltrimethoxysilane was pumped into the pipeline reactor I through pump I at a flow rate of 300 mL / min, the acid solution material was pumped into the pipeline reactor I through pump II at a flow rate of 1800 mL / min, and the alkaline solution was pumped into the pipeline reactor II through pump III at a flow rate of 60 mL / min.

[0110] The reaction temperature of pipeline reactor I is 30°C, the reaction temperature of pipeline reactor II is 35°C, the reaction residence time τ of pipeline reactor I is 110 min, the reaction residence time τ of pipeline reactor II is 210 min, and the rest is the same as Example 1-1.

[0111] The results obtained were as follows: the yield of polyvinyl siloxane microspheres was 78%, and the particle size of the polyvinyl siloxane microspheres was 3.27 μm.

[0112] Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A continuous pipeline device for preparing polyvinylsiloxane microspheres, characterized in that: It comprises a pipeline reactor I and a pipeline reactor II; both the pipeline reactor I and the pipeline reactor II are multi-side line feeding tubular reactors; The outlet of the vinyltrimethoxysilane raw material tank is connected to the main inlet of the pipeline reactor 1 through a pipeline with a stop valve and a pump 1; The outlet of the acid solution raw material tank is connected to the pump II through a pipeline provided with a stop valve, and then connected to the main inlet of the pipeline reactor I and the side line inlet of the pipeline reactor I through the pump II; The outlet of the pipeline reactor I is connected to the main inlet of the pipeline reactor II through a back pressure valve I and a one-way valve; The alkali solution raw material tank is connected to pump III through a pipeline with a stop valve, and then connected to the main inlet of pipeline reactor II and the side line inlet of pipeline reactor II through pump III; The outlet of the pipeline reactor II is connected to the inlet of the collecting tank through a back pressure valve II.

2. The continuous pipeline device for preparing polyvinylsiloxane microspheres according to claim 1, characterized in that: The outlet of the collecting tank is connected to the outlet of the reaction liquid through a pipeline with a stop valve.

3. The continuous pipeline device for preparing polyvinylsiloxane microspheres according to claim 1 or 2, characterized in that: The pipeline reactor I has 7 to 9 side line inlets, which are evenly located at different pipe lengths of the pipeline reactor I; the main inlet of the pipeline reactor I is located at the beginning of the pipeline reactor I; a pump II is provided at the main inlet and each side line inlet of the pipeline reactor I, a check valve is provided on the pipeline before each side line inlet, and a static mixer is provided on the pipeline after the main inlet and each side line inlet; the outlet of the acid solution raw material tank is connected to the main inlet of the pipeline reactor I and the side line inlet of the pipeline reactor I through the corresponding pump II; There are 7 to 9 side line inlets of the pipeline reactor II, which are located at different pipe lengths of the pipeline reactor II; the main inlet of the pipeline reactor II is located at the beginning of the pipeline reactor II, and a pump III is respectively provided at the main inlet and each side line inlet of the pipeline reactor II; a check valve is provided on the pipeline before each side line inlet, and a static mixer is provided on the pipeline after the main inlet and each side line inlet; the outlet of the alkaline solution raw material tank is connected to the main inlet of the pipeline reactor II and the side line inlet of the pipeline reactor II through the corresponding pump III.

4. The continuous pipeline device for preparing polyvinylsiloxane microspheres according to claim 3, characterized in that: The pipeline reactor I is provided with 7 side line inlets, namely, side line 1 to side line 7; the 7 side line inlets, namely, side line 1 to side line 7, are respectively located at 1 / 14, 3 / 14, 5 / 14, 7 / 14, 9 / 14, 11 / 14, and 13 / 14 of the length of the pipeline reactor I; The pipeline reactor II is provided with seven side line inlets, namely, side line 1 to side line 7; the seven side line inlets, namely, side line 1 to side line 7, are respectively located at 1 / 14, 3 / 14, 5 / 14, 7 / 14, 9 / 14, 11 / 14 and 13 / 14 of the length of the pipeline reactor II.

5. The continuous pipeline device for preparing polyvinylsiloxane microspheres according to any one of claims 1 to 4, characterized in that: The inner wall of the pipeline of the pipeline reactor I is provided with baffles, and the adjacent baffles are arranged alternately on the left and right. The angle a between each baffle and the inner wall of the pipeline is 25-31°, and the distance between the baffles is 0.5-1m; Baffles are arranged on the inner wall of the pipeline inside the pipeline reactor II, and adjacent baffles are arranged alternately on the left and right. The angle b between each baffle and the inner wall of the pipeline is 5 to 8 degrees, and the distance between the baffles is 1 to 2 meters.

6. The continuous pipeline device for preparing polyvinylsiloxane microspheres according to claim 5, characterized in that: The vinyltrimethoxysilane raw material tank, the acid solution raw material tank, and the alkali solution raw material tank are each provided with a pressure gauge.

7. A pipeline continuous synthesis method of polyvinylsiloxane microspheres, characterized in that The following steps are involved: 1) Hydrolysis: Set the feed volume ratio of vinyltrimethoxysilane: hydrochloric acid solution = 1:2-12, Vinyltrimethoxysilane is pumped into the pipeline reactor I from the main inlet of the pipeline reactor I, and the acid solution is pumped into the pipeline reactor I from the main inlet and the side line inlet of the pipeline reactor I, and a hydrolysis reaction is carried out in the pipeline reactor I at a temperature of 25 to 50° C., a reaction pressure of 1.5 to 3 MPa, and a reaction time of 10 to 30 min; 2) Polycondensation: The volume ratio of the alkaline solution to the acid solution in step 1) is set to 1:20-30; The primary reaction liquid flowing out of the pipeline reactor I is pumped into the pipeline reactor II from the main inlet of the pipeline reactor II, and the alkaline solution is pumped into the pipeline reactor II from the main inlet and the side line inlet of the pipeline reactor II, and a polycondensation reaction is carried out in the pipeline reactor II, with a reaction temperature of 25 to 55° C., a reaction pressure of 1.2 to 2.6 MPa, and a reaction time of 8 to 15 min; 3) The final reaction liquid flowing out of the pipeline reactor II enters a collection tank and is post-processed to obtain polyvinylsiloxane microspheres.

8. The pipeline continuous synthesis method of polyvinylsiloxane microspheres according to claim 7, characterized in that: The post-treatment of step 3) is as follows: the reaction product flowing out of the pipeline reactor II is centrifuged, dried, and crushed to obtain polyvinylsiloxane microspheres.

9. The pipeline continuous synthesis method of polyvinylsiloxane microspheres according to claim 7 or 8, characterized in that: The acid solution is a hydrochloric acid solution with a pH of 3.5 to 4.5; The alkaline solution is (0.1±0.01) mol / L NaOH solution.

10. The pipeline continuous synthesis method of polyvinylsiloxane microspheres according to any one of claims 7 to 9, characterized in that: The inner diameter of the pipeline reactor I is 3-20 mm, and the inner diameter of the pipeline reactor II is 8-30 mm.

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