Continuous preparation process of high-molecular-weight MQ resin

Abstract

The invention discloses a continuous preparation process of high molecular weight MQ resin, which comprises the following steps: S1, filling an annular tubular reactor with hydrochloric acid, circulating in the reactor, and keeping the hydrochloric acid to continuously enter and flow out of the reactor; s2, feeding the water glass solution into the annular tubular reactor, wherein the feeding mode is that the included angle between the feeding direction of the water glass solution and the flowing direction of liquid in the annular tubular reactor is less than 90 degrees; s3, fully mixing and reacting the water glass solution and hydrochloric acid in the annular tubular reactor, and aging to form polysilicic acid; s4, introducing polysilicic acid into an end-capping reactor, and simultaneously adding an end-capping reagent, an alcohol auxiliary agent and a solvent to carry out end-capping reaction; and S5, carrying out static phase separation to obtain an organic phase containing the MQ resin, and carrying out water washing and purification on the organic phase to obtain the MQ resin.

Description

Technical Field

[0001] This invention relates to a method for producing organosilicon resin, and more particularly to a continuous preparation process for high molecular weight MQ resin. Background Technology

[0002] Organosilicon resins possess excellent thermal stability, electrical insulation, weather resistance, and biocompatibility, making them widely used in defense, electrical industries, light industrial products, rubber and plastics, food hygiene, and other sectors, playing an irreplaceable role in the materials field. MQ resin is a type of organosilicon resin, composed of monofunctional (M-group) repeating units R3SiO. 1 / 2 and tetrafunctional (Q group) repeating SiO 4 / 2 Polysiloxanes with a special structure, formed through hydrolysis and condensation, have many advantages such as good adhesion, heat resistance, weather resistance, and flexibility, and have great application value in pressure-sensitive adhesives, liquid silicone rubber, and other fields.

[0003] Currently, the main methods for preparing MQ resin include the water glass method and the TOES method. The water glass method is more widely used due to its advantage in raw material price. Existing technologies have attempted to use the water glass method for continuous preparation of MQ resin. However, water glass has extremely high condensation reaction activity in acidic environments, and gelation easily occurs in the condensation reactor, affecting the stable operation of the reactor, especially when using high-concentration raw materials to synthesize high molecular weight MQ resin, which is even more difficult to control.

[0004] Patent CN101460543 describes the polymerization of sodium silicate in an acidic environment and the use of a powerful mixing tool to dynamically and continuously mix the reaction solution to ensure effective mixing within the reactor. This high-power continuous production method offers good mass and heat transfer, but it places high demands on the equipment, requiring corrosion resistance, high strength, and high energy consumption.

[0005] Patent CN113321809 employs SV, SK, SX, SH, and SL type static mixers to enhance mixing and limits the liquid flow rate, achieving a good mixing effect. While this method solves the gelation problem quickly and has low requirements for the mixing equipment, it places high demands on the feeding equipment and has extremely low tolerance for fluctuations. Even with excessive hydrochloric acid content, slight fluctuations during long-term operation can easily cause gelation, leading to pipeline blockage.

[0006] Patent CN114230795B describes the preparation of MQ resin using a loop reactor. Because a portion of the acidic liquid is continuously refluxed, the overall pH value remains stable, thus avoiding the gelation problem caused by sudden pH changes due to unstable flow in static mixers. This allows for continuous production of MQ resin using low-power mixing equipment. However, our in-depth research has revealed that this method can only maintain stable operation of the system for a certain period. When the content of ultra-high molecular weight resin increases to a certain level, it will still rapidly induce gelation, leading to an emergency shutdown of the equipment.

[0007] Therefore, it is necessary to propose a continuous preparation process for high molecular weight MQ resin that can ensure stable long-term operation of the device. Summary of the Invention

[0008] To address the above technical problems, this invention proposes a continuous preparation process for high molecular weight MQ resin.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A continuous preparation process for high molecular weight MQ resin includes the following steps:

[0011] S1. Fill the loop reactor with hydrochloric acid and circulate it inside the reactor to keep the hydrochloric acid continuously entering and exiting the reactor;

[0012] S2. Feed the water glass solution into the loop reactor. The feeding method is such that the angle between the water glass solution feeding direction and the liquid flow direction in the loop reactor is <90°, preferably 0°≤angle≤70°.

[0013] S3, water glass solution and hydrochloric acid are fully mixed and reacted in a loop reactor, and then aged to form polysilicic acid;

[0014] S4. Polysilicic acid is introduced into the end-capping reactor, and end-capping agent, alcohol additive and solvent are added at the same time to carry out the end-capping reaction;

[0015] S5. Static phase separation is performed to obtain an organic phase containing MQ resin. The organic phase is then washed with water and purified to obtain MQ resin.

[0016] Regarding the method of controlling the feed direction of water glass solution in this invention, the angle at which the feed pipe is inserted into the reactor loop can be directly adjusted to meet the condition that the angle between the feed pipe and the liquid flow direction in the loop reactor is <90°, preferably 0°≤angle≤70°. Alternatively, the above angle requirement can be met by inserting the pipe into the loop at any angle and then changing direction. No specific restrictions are imposed here.

[0017] As a further preferred option, in step S2, the feed pipe of the water glass solution is a reducing pipe, and the diameter of the pipe decreases from large to small along the material outflow direction; preferably, the diameter of the pipe at the material outlet is 1 / 10 to 1 / 3 of the diameter before the reduction.

[0018] As some preferred examples of the present invention, in the loop reactor, the feed rate of hydrochloric acid is such that the pH of the reaction system is always kept ≤2.

[0019] As some preferred examples of the present invention, the circulation intensity of the loop reactor is provided by a power device with a power density of less than 10 kW / m³. 3 Preferably, the power equipment is selected from one or more of diaphragm pumps, centrifugal pumps, and peristaltic pumps.

[0020] The reflux ratio of the loop reactor can be adjusted by adjusting the power density of the power equipment. An advantageous reflux ratio range is, for example, 10-80, preferably 20-65. Increasing the reflux ratio is beneficial for better mixing of materials, but the reflux ratio should not be too high, otherwise it will broaden the molecular weight distribution of the product. Preferably, the reflux ratio does not exceed 80, more preferably not exceeding 65. Decreasing the reflux ratio is beneficial for narrower molecular weight distribution of the product, but the reflux ratio should not be too low, otherwise the mixing efficiency will be poor and the system will easily gel. Preferably, the reflux ratio is not less than 10, more preferably not less than 20.

[0021] As some preferred examples of the present invention, the mass concentration of the water glass solution fed in step S2 is 10-30 wt%, preferably 16-28 wt%.

[0022] As some preferred examples of the present invention, in the loop reactor, the reaction temperature is 5-30°C and the reaction time is 0.1-10 min.

[0023] As some preferred examples of the present invention, the aging process is performed at a temperature of 5-30°C for a time of 0.01-10 min.

[0024] As some preferred examples of the present invention, the end-capping agent is selected from one or more of trimethylchlorosilane, hexamethyldisiloxane, tetramethyldivinyldisiloxane, and vinyltrimethylchlorosilane; preferably, the amount of end-capping agent is 20-40 wt% of the mass of water glass;

[0025] Preferably, the alcohol additive is selected from one or more of methanol, ethanol, isopropanol, and butanol; preferably, the amount of alcohol additive used is 20-40 wt% of the water glass mass.

[0026] Preferably, the solvent is selected from one or more of benzene, xylene, hexamethyldisiloxane, and C6-C16 long-chain aliphatic hydrocarbons; preferably, the amount of solvent added is 50-200 wt% of the mass of water glass.

[0027] As some preferred examples of the present invention, the end-capping reaction is carried out at a temperature of 50-90°C and for a reaction time of 1-6 hours.

[0028] As some preferred examples of the present invention, the purification method in step S5 is distillation or rectification to remove water and some solvent from the product and obtain the MQ resin with the required solid content of the product.

[0029] This invention does not impose any restrictions on the shape of the loop reactor; it can be triangular, rectangular, square, trapezoidal, rhomboid, circular, elliptical, or any other irregular shape.

[0030] In this invention, the aging reactor can be a tubular reactor, a batch reactor, or a microchannel reactor, etc.

[0031] In this invention, the end-capping reactor is a tubular reactor or a batch reactor.

[0032] In this invention, the phase separation can be achieved using a phase separator, such as a vertical phase separator tank or a horizontal phase separator tank.

[0033] This invention, by adjusting the raw material feeding method in the loop reactor, can not only produce high molecular weight MQ resin, but also reduce the content of ultra-large molecular weight resin (Mw greater than 300,000), which can delay the occurrence of gelation and significantly extend the stable operation cycle of the device; at the same time, the improvement of the water glass feeding method narrows the molecular weight distribution of the product and improves the product quality. Attached Figure Description

[0034] Figure 1 The present invention is a process flow diagram of the production of MQ resin using a square loop reactor, wherein the angle between the feed direction of the water glass solution and the flow direction of the liquid in the reactor is 0°.

[0035] Figure 2 This is a partial structural illustration of the present invention, showing that the angle between the water glass solution feeding direction and the liquid flow direction in the reactor is 30°.

[0036] Figure 3 This is a partial structural diagram showing the direction of water glass solution feeding when the circular loop reactor is used in the present invention.

[0037] Figure 4 This is a partial structural diagram of the water glass solution feed pipe, which is a variable diameter pipe, in the present invention.

[0038] Figure 5 The process flow diagram for producing MQ resin using a square loop reactor is shown in Comparative Example 1, where the angle between the feed direction of the water glass solution and the liquid flow direction in the reactor is 90°. Detailed Implementation

[0039] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0040] Unless otherwise specified, all raw materials and reagents used in this invention can be purchased commercially. The main raw material information for the examples is as follows:

[0041] Water glass: Laizhou sodium silicate, <37%;

[0042] Hydrochloric acid: Far East Fine Chemical Co., Ltd., 36%;

[0043] Hexamethyldisiloxane: Aladdin, 99%;

[0044] Trimethylchlorosilane: Aladdin, 99%;

[0045] Isopropanol / ethanol: Sinopec, 99%;

[0046] Tetramethyldivinyldisiloxane: Aladdin, 99%.

[0047] In the following examples, the molecular weight of the resin was quantified using GPC:

[0048] Gel Chromatography (GPC): The GPC system is equipped with a unit pump, column oven, differential detector, autosampler, and chromatography workstation. Chromatographic conditions: Column: Agilent PLgel MIXED-D 5μm (7.5 x 300 mm); Mobile phase: ethyl acetate; Flow rate: 1.0 mL / min; Column temperature: 40℃; Detector temperature: 40℃; Injection volume: 10 μL / s.

[0049]

Example 1

[0050] A 15% hydrochloric acid aqueous solution was pumped into the loop reactor at a rate of 250 g / min, and the circulation pump was started. A 28 wt% water glass solution was continuously fed into the loop reactor at a rate of 450 g / min, with the feeding method ensuring that the angle between the water glass solution feeding direction and the liquid flow direction in the loop reactor was 0°. Figure 1 (As shown). The reaction temperature was maintained at 5°C, the residence time at 10 min, the reflux ratio at 50, and the measured pH of the system was 0.50. Subsequently, the reaction solution was transferred to another tubular reactor for aging at 5°C for 10 min.

[0051] The aged reaction solution, ethanol, xylene, and hexamethyldisiloxane were continuously added to a batch-type end-capping reactor at rates of 700 g / min, 180 g / min, 350 g / min, and 180 g / min, respectively. The end-capping reaction temperature was set at 90 °C, and the reaction was carried out for 1 hour. The end-capping product was sent to a continuous vertical phase-separation tank for phase separation. The organic phase was washed with water, separated again, and then continuously fed into a distillation column to remove water and some solvent from the product, yielding an MQ resin solution.

[0052] The obtained MQ resin was determined by GPC to have a weight-average molecular weight of 18,658, a molecular weight distribution (PDI) of 1.68, and a proportion of ultra-high molecular weight resin (weight-average molecular weight greater than 30w) of 0.85wt%. The linear velocity in the loop of the reactor did not decrease after 100h of continuous operation.

[0053]

Example 2

[0054] A 15% hydrochloric acid aqueous solution was pumped into a loop reactor at a rate of 250 g / min, and the circulation pump was started. A 28 wt% water glass solution was continuously fed into the loop reactor at a rate of 450 g / min, with the feed direction of the water glass solution forming a 5° angle with the liquid flow direction in the loop reactor. The reaction temperature was maintained at 30°C, the residence time at 0.1 min, the reflux ratio at 80, and the measured pH of the system was 0.50. Subsequently, the reaction solution was pumped into another tubular reactor for aging at 30°C for 0.01 min.

[0055] The aged reaction solution, methanol, hexamethyldisiloxane, and trimethylchlorosilane were continuously added to a batch-type end-capping reactor at rates of 700 g / min, 90 g / min, 225 g / min, and 90 g / min, respectively. The end-capping reaction temperature was set at 50 °C, and the reaction was carried out for 6 hours. The end-capping product was sent to a continuous vertical phase-separation tank for phase separation. The organic phase was washed with water, separated again, and then continuously fed into a distillation column to remove water and some solvent from the product, yielding an MQ resin solution.

[0056] The obtained MQ resin was determined by GPC to have a weight-average molecular weight of 18923, a molecular weight distribution (PDI) of 1.73, and a proportion of ultra-high molecular weight resin (weight-average molecular weight greater than 30w) of 0.86%. The linear velocity in the loop showed no decay after 100 hours of continuous operation of the reactor.

[0057]

Example 3

[0058] An 18% hydrochloric acid aqueous solution was pumped into a loop reactor at a rate of 150 g / min, and the circulation pump was started. A 16 wt% water glass solution was continuously fed into the loop reactor at a rate of 450 g / min, with the feed direction of the water glass solution forming a 15° angle with the liquid flow direction in the loop reactor. The reaction temperature was maintained at 30°C, the residence time at 10 min, the reflux ratio at 10, and the measured pH of the system was 0.42. Subsequently, the reaction solution was pumped into another tubular reactor for aging at 30°C for 10 min.

[0059] The aged reaction solution, isopropanol, toluene, and tetramethyldivinyldisiloxane were continuously added to a batch-type end-capping reactor at rates of 700 g / min, 180 g / min, 675 g / min, and 180 g / min, respectively. The end-capping reaction temperature was set at 90 °C, and the reaction was carried out for 1 hour. The end-capping product was sent to a continuous vertical phase-separation tank for phase separation. The organic phase was washed with water, separated again, and then continuously fed into a distillation column to remove water and some solvent from the product, yielding an MQ resin solution.

[0060] The obtained MQ resin was determined by GPC to have a weight-average molecular weight of 18206, a molecular weight distribution (PDI) of 1.52, and a proportion of ultra-high molecular weight resin (weight-average molecular weight greater than 30w) of 0.73%. The linear velocity in the loop showed no decay after 100 hours of continuous operation of the reactor.

[0061]

Example 4

[0062] A 15% hydrochloric acid aqueous solution was pumped into the loop reactor at a rate of 250 g / min, and the circulation pump was started. A 28 wt% water glass solution was continuously fed into the loop reactor at a rate of 450 g / min, with the feeding method such that the angle between the water glass solution feeding direction and the liquid flow direction in the loop reactor was 30°. Figure 2 (As shown). The reaction temperature was maintained at 30℃, the residence time at 5 min, the reflux ratio at 45, and the measured pH of the system was 0.50. Subsequently, the reaction solution was transferred to another tubular reactor for aging at 5℃ for 10 min.

[0063] The aged reaction solution, butanol, heptane, and vinyltrimethylchlorosilane were continuously added to a batch-type end-capping reactor at rates of 700 g / min, 180 g / min, 350 g / min, and 180 g / min, respectively. The end-capping reaction temperature was set at 80 °C, and the reaction was carried out for 2 hours. The end-capping product was sent to a continuous vertical phase-separation tank for phase separation. The organic phase was washed with water, separated again, and then continuously fed into a distillation column to remove water and some solvent from the product, yielding an MQ resin solution.

[0064] The obtained MQ resin was determined by GPC to have a weight-average molecular weight of 18,658, a molecular weight distribution (PDI) of 1.60, and a proportion of ultra-high molecular weight resin (weight-average molecular weight greater than 30w) of 0.68%. The linear velocity in the loop showed no decay after 100 hours of continuous operation of the reactor.

[0065]

Example 5

[0066] A 15% hydrochloric acid aqueous solution was pumped into a loop reactor at a rate of 250 g / min, and the circulation pump was started. A 28 wt% water glass solution was continuously fed into the loop reactor at a rate of 450 g / min, with the feed direction of the water glass solution forming a 50° angle with the liquid flow direction in the loop reactor. The reaction temperature was maintained at 10℃, the residence time at 5 min, the reflux ratio at 55, and the measured pH of the system was 0.50. Subsequently, the reaction solution was pumped into another tubular reactor for aging at 5℃ for 10 min.

[0067] The aged reaction solution, methanol, xylene, and hexamethyldisiloxane were continuously added to a batch-type end-capping reactor at rates of 700 g / min, 180 g / min, 350 g / min, and 180 g / min, respectively. The end-capping reaction temperature was set at 80 °C, and the reaction was carried out for 3 hours. The end-capping product was sent to a continuous vertical phase-separation tank for phase separation. The organic phase was washed with water, separated again, and then continuously fed into a distillation column to remove water and some solvent from the product, yielding an MQ resin solution.

[0068] The obtained MQ resin was determined by GPC to have a weight-average molecular weight of 18,556, a molecular weight distribution (PDI) of 1.62, and a proportion of ultra-high molecular weight resin (weight-average molecular weight greater than 30w) of 0.80%. The linear velocity in the loop showed no decay after 100 hours of continuous operation of the reactor.

[0069]

Example 6

[0070] A 15% hydrochloric acid aqueous solution was pumped into a loop reactor at a rate of 250 g / min, and the circulation pump was started. A 28 wt% water glass solution was continuously fed into the loop reactor at a rate of 450 g / min, with the feed direction of the water glass solution forming a 70° angle with the liquid flow direction in the loop reactor. The reaction temperature was maintained at 10℃, the residence time at 5 min, the reflux ratio at 60, and the measured pH of the system was 0.50. Subsequently, the reaction solution was pumped into another tubular reactor for aging at 15℃ for 10 min.

[0071] The aged reaction solution, methanol, xylene, and hexamethyldisiloxane were continuously added to a batch-type end-capping reactor at rates of 700 g / min, 180 g / min, 350 g / min, and 180 g / min, respectively. The end-capping reaction temperature was set at 80 °C, and the reaction was carried out for 3 hours. The end-capping product was sent to a continuous vertical phase-separation tank for phase separation. The organic phase was washed with water, separated again, and then continuously fed into a distillation column to remove water and some solvent from the product, yielding an MQ resin solution.

[0072] The obtained MQ resin was determined by GPC to have a weight-average molecular weight of 18756, a molecular weight distribution (PDI) of 1.63, and a proportion of ultra-high molecular weight resin (weight-average molecular weight greater than 30w) of 0.87%. The linear velocity in the loop showed no decay after 100 hours of continuous operation of the reactor.

[0073]

Example 7

[0074] A 15% hydrochloric acid aqueous solution was pumped into a loop reactor at a rate of 250 g / min, and the circulation pump was started. A 28 wt% water glass solution was continuously fed into the loop reactor at a rate of 450 g / min, with the feed direction of the water glass solution forming a 45° angle with the liquid flow direction in the loop reactor. The reaction temperature was maintained at 10℃, the residence time at 5 min, the reflux ratio at 55, and the measured pH of the system was 0.50. Subsequently, the reaction solution was pumped into another tubular reactor for aging at 15℃ for 10 min.

[0075] The aged reaction solution, methanol, xylene, and hexamethyldisiloxane were continuously added to a batch-type end-capping reactor at rates of 700 g / min, 180 g / min, 350 g / min, and 180 g / min, respectively. The end-capping reaction temperature was set at 80 °C, and the reaction was carried out for 3 hours. The end-capping product was sent to a continuous vertical phase-separation tank for phase separation. The organic phase was washed with water, separated again, and then continuously fed into a distillation column to remove water and some solvent from the product, yielding an MQ resin solution.

[0076] The obtained MQ resin was determined by GPC to have a weight-average molecular weight of 18,748, a molecular weight distribution (PDI) of 1.62, and a proportion of ultra-high molecular weight resin (weight-average molecular weight greater than 30w) of 0.82%. The linear velocity in the loop showed no decay after 100 hours of continuous operation of the reactor.

[0077]

Example 8

[0078] A 15% hydrochloric acid aqueous solution was pumped into the loop reactor at a rate of 250 g / min, and the circulation pump was started. A 28 wt% water glass solution was continuously fed into the loop reactor at a rate of 450 g / min. The feeding method was such that the angle between the feed direction of the water glass solution and the liquid flow direction in the loop reactor was 30°, and the diameter of the pipe at the material outlet of the feed pipe was 1 / 5 of the diameter before the diameter change. Figure 4 (As shown). The reaction temperature was maintained at 30℃, the residence time at 5 min, the reflux ratio at 40, and the measured pH of the system was 0.50. Subsequently, the reaction solution was transferred to another tubular reactor for aging at 5℃ for 10 min.

[0079] The aged reaction solution, butanol, heptane, and vinyltrimethylchlorosilane were continuously added to a batch-type end-capping reactor at rates of 700 g / min, 180 g / min, 350 g / min, and 180 g / min, respectively. The end-capping reaction temperature was set at 80 °C, and the reaction was carried out for 2 hours. The end-capping product was sent to a continuous vertical phase-separation tank for phase separation. The organic phase was washed with water, separated again, and then continuously fed into a distillation column to remove water and some solvent from the product, yielding an MQ resin solution.

[0080] The obtained MQ resin was determined by GPC to have a weight-average molecular weight of 18,735, a molecular weight distribution (PDI) of 1.57, and a proportion of ultra-high molecular weight resin (weight-average molecular weight greater than 30w) of 0.53%. The linear velocity in the loop showed no decay after 100 hours of continuous operation of the reactor.

[0081] Comparative Example 1

[0082] MQ resin was prepared using essentially the same method and equipment as in Example 1, except that the angle between the water glass solution feed direction and the liquid flow direction in the loop reactor was changed to 90°. Figure 5 (As shown). The obtained MQ resin was determined by GPC to have a weight-average molecular weight of 18925, a molecular weight distribution (PDI) of 1.92, and a proportion of ultra-high molecular weight resin (weight-average molecular weight greater than 30w) of 1.79%. The linear velocity of the reactor decreased significantly during continuous operation, and gelled and became blocked after 42 hours of operation.

[0083] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A continuous preparation process for high molecular weight MQ resin, characterized in that, The process includes the following: S1. Fill the loop reactor with hydrochloric acid and circulate it inside the reactor to keep the hydrochloric acid continuously entering and exiting the reactor; S2. Feed the water glass solution into the loop reactor. The feeding method is such that the angle between the water glass solution feeding direction and the liquid flow direction in the loop reactor is <90°, preferably 0°≤angle≤70°. S3, water glass solution and hydrochloric acid are fully mixed and reacted in a loop reactor, and then aged to form polysilicic acid; S4. Polysilicic acid is introduced into the end-capping reactor, and end-capping agent, alcohol additive and solvent are added at the same time to carry out the end-capping reaction; S5. Static phase separation is performed to obtain an organic phase containing MQ resin. The organic phase is then washed with water and purified to obtain MQ resin.

2. The continuous preparation process of high molecular weight MQ resin according to claim 1, characterized in that, In a loop reactor, the feed rate of hydrochloric acid is used to maintain the pH of the reaction system at ≤2.

3. The continuous preparation process of high molecular weight MQ resin according to claim 1, characterized in that, The circulation intensity of the loop reactor is provided by a power unit with a power density of less than 10 kW / m³. 3 Preferably, the power equipment is selected from one or more of diaphragm pumps, centrifugal pumps, and peristaltic pumps.

4. The continuous preparation process of high molecular weight MQ resin according to any one of claims 1-3, characterized in that, The mass concentration of the water glass solution fed in step S2 is 10-30 wt%, preferably 16-28 wt%.

5. The continuous preparation process of high molecular weight MQ resin according to any one of claims 1-4, characterized in that, In the loop reactor, the reaction temperature is 5-30℃ and the reaction time is 0.1-10min.

6. The continuous preparation process of high molecular weight MQ resin according to any one of claims 1-5, characterized in that, The aging process is carried out at a temperature of 5-30℃ for a duration of 0.01-10 minutes.

7. The continuous preparation process of high molecular weight MQ resin according to any one of claims 1-6, characterized in that, The end-capping agent is selected from one or more of trimethylchlorosilane, hexamethyldisiloxane, tetramethyldivinyldisiloxane, and vinyltrimethylchlorosilane; preferably, the amount of end-capping agent used is 20-40 wt% of the mass of water glass; Preferably, the alcohol additive is selected from one or more of methanol, ethanol, isopropanol, and butanol; preferably, the amount of alcohol additive used is 20-40 wt% of the water glass mass. Preferably, the solvent is selected from one or more of benzene, xylene, hexamethyldisiloxane, and C6-C16 long-chain aliphatic hydrocarbons; preferably, the amount of solvent added is 50-200 wt% of the mass of water glass.

8. The continuous preparation process of high molecular weight MQ resin according to any one of claims 1-7, characterized in that, The end-capping reaction is carried out at a temperature of 50-90℃ for 1-6 hours.

9. The continuous preparation process of high molecular weight MQ resin according to any one of claims 1-8, characterized in that, In step S5, the purification method is distillation or rectification.

10. The continuous preparation process of high molecular weight MQ resin according to any one of claims 1-9, characterized in that, In step S2, the feed pipe of the water glass solution is a reducing pipe, and the diameter of the pipe decreases from large to small along the material outflow direction; preferably, the diameter of the pipe at the material outlet is 1 / 10 to 1 / 3 of the diameter before the reducing pipe.

Images