Process and device for synthesizing silicone oil through cavity type falling film efficient polycondensation and self-feedback synthesis process thereof

Abstract

The invention belongs to the technical field of synthesis of silicone oil, and discloses a process for synthesizing silicone oil through cavity type falling film efficient polycondensation, a device used in the process and a self-feedback synthesis process of the process. The method comprises the following steps: mixing a linear body, a catalyst and an end-capping reagent by using a falling film reactor as a reactor, pumping the mixture into the reactor from the upper part of the reactor, and reacting to prepare the silicone oil. According to the invention, the falling-film reactor is used as a reactor, and the high-temperature environment of the falling-film reactor and the greatly increased cavity type thermal contact surface are utilized to realize rapid and efficient polymerization film formation of a linear body; meanwhile, through blowing of nitrogen, a large amount of water which is rapidly generated in a linear body polymerization reaction is rapidly brought away, and the inactivation influence on a catalyst due to the fact that water in a reaction kettle in a traditional linear body reaction system cannot be discharged in time is solved; through gravity falling film, the reaction is continuously and rapidly carried out, continuous and efficient production of the silicone oil is realized, the process is simple and efficient, and the obtained product is low in ring content, low in hydroxyl content and good in stability.

Description

Technical Field

[0001] This invention belongs to the field of silicone oil synthesis technology, and specifically relates to a process for high-efficiency cavity falling film condensation polymerization to synthesize silicone oil, the apparatus used in the process, and its self-feedback synthesis process. Background Technology

[0002] The main process routes for synthesizing vinyl (methyl) silicone oil on the market are as follows: (1) Dimethylsiloxane cyclic (DMC) and vinyl (methyl) end-capping agent are first ring-opened and then polymerized under a catalyst. After all the monomer DMC is converted, a terminator is added to deactivate the catalyst, or the catalyst is decomposed at high temperature. Then, unreacted low molecules are removed under vacuum conditions of less than 1000 Pa to obtain vinyl (methyl) silicone oil. However, this method has a low ring-opening rate. (2) Using linear monomers as raw materials, alkaline catalysts are used in batch reaction. Large cyclic compounds (D4, D5, etc.) are easily generated during the synthesis process. The above process routes are complicated, have low production efficiency, high energy consumption, poor batch stability, and cannot achieve continuous production. There are also a large number of cyclic compounds (D4, D5, etc.) remaining. In recent years, cyclic compounds have been found to be toxic and easily accumulate in higher organisms, causing persistent environmental and biological hazards. Therefore, it is necessary to develop a high-efficiency, continuous production silicone oil synthesis process with low cyclic compound content in the product to meet the market requirements for silicone oil. Summary of the Invention

[0003] In order to overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a process for efficient cavity falling film polymerization to form silicone oil.

[0004] The process of this invention uses hydroxyl-terminated polydimethylsiloxane (linear) as raw material and a cavity falling film reactor as reactor to achieve high-efficiency polycondensation while avoiding the generation of a large number of cyclic compounds (D4, D5, etc.), and can continuously produce silicone oil.

[0005] Another object of the present invention is to provide an apparatus for use in the above-described process.

[0006] Another object of the present invention is to provide a self-feedback synthesis process based on the above-described apparatus.

[0007] The objective of this invention is achieved through the following solution: The first aspect is a process for high-efficiency condensation polymerization of silicone oil using a cavity falling film reactor. The linear polymer, catalyst A, and end-capping agent are mixed and injected into the reactor from the top to react, thereby preparing silicone oil.

[0008] The process of this invention uses a falling film reactor as the reactor. Under the action of gravity, the raw materials react rapidly as they descend from the inner wall of the reactor, and the reaction products can be obtained from the bottom of the reactor.

[0009] Traditional methods using linear polymers as raw materials in reactors suffer from drawbacks. Large amounts of water generated during the reaction cannot be drained promptly, the catalyst is easily deactivated by water, and the resulting product has a high hydroxyl content, making it difficult to process. Alkali-catalyzed reactions produce a large number of cyclic compounds, resulting in products that do not meet practical requirements. Therefore, cyclic compounds are currently often used as raw materials, but the ring-opening rate is low (only 85%), and the product contains a high cyclic compound content. This invention utilizes low-viscosity linear polymers as raw materials and employs a cavity falling film reactor. During the film-forming process, the mixture falls along the reactor's inner wall, allowing for rapid heat transfer and efficient water removal. This results in a fast reaction rate and efficient cavity falling film polymerization to form silicone oil, producing a product with low cyclic compound content, low hydroxyl content, and good stability.

[0010] As a preferred embodiment of the present invention, the linear body may be hydroxyl-terminated polydimethylsiloxane.

[0011] As a preferred technical solution of the present invention, the reaction time of the material in the reactor can be controlled by controlling the flow rate of the material fed into the reactor, such as 1-20 min.

[0012] As a preferred technical solution of the present invention, the amount of the capping agent can be the conventional amount used in the art, such as the mass ratio of the linear body to the capping agent being 100:0.1-100:15.

[0013] As a preferred embodiment of the present invention, the end-capping agent may include methyl silicone oil, hydrogen-containing silicone oil, alkoxy silicone oil, or vinyl silicone oil, etc.

[0014] As a preferred embodiment of the present invention, the viscosity of the end-capping agent is preferably 15-80 mm / s.

[0015] As a preferred technical solution of the present invention, the end-capping agent can be directly purchased or prepared by oneself. Specifically, it can be prepared by the following steps: after mixing the linear body with the end-capping agent, catalyst A is added and reacted for 10-40 minutes at a temperature of 50-100℃ and a vacuum degree of -0.10~-0.05MPa, followed by neutralization with an inorganic neutralizing agent, and then filtration to obtain the end-capping agent.

[0016] Furthermore, the end-capping agent can be a conventionally used end-capping agent, such as, but not limited to, at least one of hexamethyldisiloxane, tetramethyldisiloxane, vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, tetramethyldivinyldisiloxane, etc.

[0017] Furthermore, the mass ratio of the linear agent to the end-capping agent used is 100:1-100:20.

[0018] Furthermore, the amount of the neutralizing agent is determined to be 1.1-1.5 times the amount of catalyst in the silicone oil system.

[0019] Furthermore, the inorganic neutralizing agent may be selected from, but is not limited to, at least one of magnesium oxide, sodium carbonate, sodium bicarbonate, zinc oxide, etc.

[0020] Furthermore, the neutralization time can be 10-50 minutes.

[0021] Furthermore, the above reaction can be carried out in a reaction vessel.

[0022] In the above text, the catalyst A mentioned in the text can be any catalyst commonly used in linear polymerization reactions, such as at least one of linear phosphazene chloride or modified phosphazene chloride.

[0023] This invention uses methyl silicone oil, hydrogen-containing silicone oil, alkoxy silicone oil, or vinyl silicone oil with a viscosity of 15-80 mm / s as end-capping agents. The hydroxyl groups in the silicone oil structure are capped, achieving a low hydroxyl content. The structure contains silicone oil segments, which do not affect the normal reaction process while exhibiting high activity. Furthermore, the increased number of segments significantly raises the boiling point, demonstrating high-temperature resistance and making it suitable for the high-temperature environment of falling film reactors. Conventional small-molecule end-capping agents such as hexamethyldisiloxane, tetramethyldisiloxane, vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and tetramethyldivinyldisiloxane are unsuitable for the falling film reactor used in this invention. When these agents are introduced into the reactor, under high-temperature conditions, their low boiling points lead to easy volatilization in the reaction environment, resulting in a low end-capping rate and a high hydroxyl content in the obtained silicone oil.

[0024] The end-capping agent used in this invention overcomes the instability of traditional small-molecule end-capping agents at high temperatures. A falling film reactor can be used as the reactor, utilizing the high-temperature environment and significantly increased cavity-type thermal contact surface of the falling film reactor to achieve rapid and efficient polymerization of linear polymers into films. At the same time, the large amount of water generated rapidly by the linear polymer polymerization reaction is quickly removed by nitrogen blowing, solving the problem of catalyst deactivation caused by the inability to remove water from the reactor in a timely manner in traditional linear polymer reaction systems. Gravity-driven falling film allows the reaction to proceed continuously and rapidly, achieving continuous and efficient production of silicone oil. The process is simple and efficient, and the resulting product has low cyclic content, low hydroxyl content, and good stability.

[0025] As a preferred embodiment of the present invention, catalyst A can be a modified linear phosphazene chloride, such as the modified linear phosphazene chloride prepared according to CN118406080A. The modified linear phosphazene chloride structure improves stability by replacing chlorine with a low-activity group. Using it as a catalyst, even with hydroxyl-terminated polydimethylsiloxane (linear form) as a raw material, a 98% conversion rate can be achieved, resulting in high efficiency, low cyclicity, and low hydroxyl value polymerization, while avoiding the use of cyclic forms (D4, D5, etc.) as raw materials. Simultaneously, virtually no cyclic forms are generated during the reaction, making the linear product obtained from the polymerization more suitable for practical applications.

[0026] As a preferred embodiment of the present invention, the amount of catalyst A can be 10-100 ppm, more preferably 20-50 ppm.

[0027] As a preferred embodiment of the present invention, the vacuum degree in the reactor can be -0.10 to -0.05 MPa.

[0028] As a preferred embodiment of the present invention, the bubbling rate of the inert gas in the reactor can be 0.1-2 kg / h. The inert gas can be nitrogen or the like.

[0029] As a preferred embodiment of the present invention, the heat preservation temperature of the reactor can be 100-200℃, more preferably 100-170℃.

[0030] As a preferred embodiment of the present invention, the mixing of the linear body, catalyst A, and end-capping agent can be carried out at room temperature.

[0031] As a preferred embodiment of the present invention, the catalyst A and the capping agent are first mixed evenly and then mixed with the linear body.

[0032] As a preferred embodiment of the present invention, the catalyst A and the capping agent are first mixed evenly in a static mixer, and then mixed evenly with the linear body in another static mixer.

[0033] In the method of the present invention, the silicone oil obtained by the reaction in the falling film reactor is neutralized and de-lowered to obtain purified silicone oil.

[0034] Furthermore, the neutralization can be achieved by adding a neutralizing agent. The neutralizing agent can be any conventionally used neutralizing agent, such as, but not limited to, at least one selected from, but not limited to, methyldivinyldisilazane (vinylsilazane), hexamethyldisilazane (silazane), diethylamine, triethylamine, etc.

[0035] Furthermore, the neutralization can be carried out at 60-130°C.

[0036] Furthermore, the neutralization reaction time can be 10-60 minutes.

[0037] Furthermore, the neutralization can be carried out in a reaction vessel, a static balancer, or a dynamic reactor.

[0038] Furthermore, the amount of the neutralizing agent is 1.1-1.5 times the amount of the catalyst in the reaction system.

[0039] Furthermore, the aforementioned degradation can be carried out using conventional methods, such as molecular evaporators, or at a vacuum of -0.10 to -0.05 MPa and a temperature of 140-200°C.

[0040] Furthermore, it is preferable to adjust the temperature of the material exiting the falling film reactor before neutralization. The temperature can be adjusted to 60-120℃.

[0041] Furthermore, the temperature adjustment can be achieved by adding the material to a temperature control device such as a heat exchanger.

[0042] Secondly, the silicone oil obtained by the present invention through the falling film reactor is a silicone oil with a relatively large molecular weight. In order to obtain a silicone oil with a lower viscosity, it can be further processed.

[0043] For example, the silicone oil obtained by the reaction in a falling film reactor can be processed by the following steps: reacting the obtained silicone oil with a capping agent, then adding a neutralizing agent to neutralize and de-lower the molecular weight to obtain silicone oils of different molecular weights.

[0044] This invention utilizes the reaction of a small-molecule end-capping agent with a high-molecular-weight silicone oil to obtain a silicone oil with low viscosity, high transparency, and low hydroxyl content. Different molecular weight silicone oils can be obtained by adjusting the amount of end-capping agent added.

[0045] In the technical solution of the present invention, the end-capping agent can be a conventionally used end-capping agent, such as at least one selected from, but not limited to, hexamethyldisiloxane, tetramethyldisiloxane, vinyltrimethoxysilane, vinyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, tetramethyldivinyldisiloxane, etc.

[0046] In the technical solution of the present invention, the mass ratio of the end-capping agent to the silicone oil can be 0.1:100-20:100.

[0047] In the technical solution of the present invention, the silicone oil and the end-capping agent can react in a reaction vessel, a static balancer, or a dynamic reactor.

[0048] In the technical solution of the present invention, the reaction temperature can be 60-120℃.

[0049] In the technical solution of the present invention, the reaction time can be 10-60 min.

[0050] In the technical solution of the present invention, the silicone oil and the end-capping agent can be mixed evenly in a static mixer before the reaction.

[0051] In the technical solution of the present invention, the neutralizing agent can be a conventionally used neutralizing agent, such as at least one selected from, but not limited to, tetramethyldisinyldisilazane (vinylsilazane), hexamethyldisilazane (silazane), diethylamine, triethylamine, etc.

[0052] In the technical solution of the present invention, the neutralization can be carried out at 60-130°C.

[0053] In the technical solution of the present invention, the neutralization time can be 10-60 minutes.

[0054] In the technical solution of the present invention, the amount of neutralizing agent is determined to be 1.1-1.5 times the content of catalyst in the silicone oil system.

[0055] In the technical solution of the present invention, the neutralization can be carried out in a reaction vessel, a static balancer, or a dynamic reactor.

[0056] In the technical solution of the present invention, the de-lowering can be carried out by conventional methods, such as using a molecular evaporator, or under a vacuum of -0.10 to -0.05 MPa and a temperature of 140-200°C.

[0057] In the technical solution of this invention, the temperature of the silicone oil obtained in the falling film reactor is preferably adjusted before it reacts with the capping agent. The temperature can be adjusted to 60-120°C. This temperature adjustment can be achieved by adding the silicone oil to a temperature control device such as a heat exchanger.

[0058] Thirdly, the process of this invention enables self-feedback of the end-capping agent. Specifically, the end-capping agent used in the process of this invention can be obtained by further processing the silicone oil prepared by the falling film reactor.

[0059] Specifically, the process includes the following steps: reacting the obtained silicone oil with the end-capping agent and catalyst A, then adding a neutralizing agent to neutralize it, filtering, and obtaining the end-capping agent suitable for the process of this invention.

[0060] In the technical solution of the present invention, the mass ratio of the end-capping agent to the silicone oil can be 0.1:100-20:100.

[0061] In the technical solution of the present invention, the amount of catalyst A can be 10-100 ppm, preferably 20-50 ppm.

[0062] In the above text, catalyst A may be at least one of linear phosphazene chloride or modified phosphazene chloride.

[0063] In the technical solution of the present invention, the reaction temperature can be 60-120℃.

[0064] In the technical solution of the present invention, the reaction time can be 10-60 min.

[0065] In the technical solution of the present invention, the reaction can be carried out in a reaction vessel, a static balancer, or a dynamic reactor.

[0066] In the technical solution of the present invention, the pre-reaction materials can be mixed in a static mixer.

[0067] In the technical solution of the present invention, the neutralizing agent may be selected from, but is not limited to, at least one of inorganic neutralizing agents such as magnesium oxide, sodium carbonate, sodium bicarbonate, and zinc oxide.

[0068] In the technical solution of the present invention, the amount of neutralizing agent is 1.1-1.5 times the amount of catalyst in the silicone oil system.

[0069] In the technical solution of the present invention, the neutralization time can be 10-50 minutes.

[0070] In the technical solution of the present invention, the neutralization reaction can be carried out in a reaction vessel or a dynamic reactor.

[0071] In the technical solution of this invention, it is preferable to adjust the temperature of the silicone oil before the reaction. The temperature can be adjusted to 60-120℃. The temperature adjustment can be performed by adding the silicone oil to a temperature control device such as a heat exchanger.

[0072] The end-capping agent used in the process of this invention, except for the one that needs to be added separately at the beginning of production, can be obtained by further processing the silicone oil obtained from the reaction. The processing method is simple, and the end-capping agent has good stability between different batches, which is more conducive to the continuous and stable production.

[0073] Fourthly, the present invention also provides an apparatus for the above-described process, comprising a falling film reactor, a temperature control device, and a neutralization reactor connected in sequence.

[0074] The temperature control device is connected to the lower outlet of the falling film reactor.

[0075] The temperature control device is connected to one or more neutralization reactors.

[0076] Furthermore, the temperature control device is used to adjust the temperature of the material obtained from the falling film reactor reaction. Any device that can achieve temperature control can be used in this device, such as a heat exchanger.

[0077] Furthermore, a static mixer can be provided between the temperature control device and the neutralization reactor. The silicone oil and neutralizing agent, after temperature adjustment, can be added to the static mixer and mixed evenly before being added to the neutralization reactor for reaction.

[0078] Furthermore, the neutralization reactor is used to carry out the neutralization reaction. Any device that can perform this function can be used as a neutralization reactor, such as a reaction vessel, a static balancer, or a dynamic reactor.

[0079] Furthermore, the neutralization reactor can be connected to a descaling device. The material after the neutralization reaction can be descaled to remove small molecules. The descaling device can be any device conventionally used in the art, such as a molecular evaporator.

[0080] When a silicone oil with a low molecular weight is required or when preparing end-capping agents, further processing is necessary before neutralization. Furthermore, a secondary reactor may be provided between the temperature control device and the neutralization reactor.

[0081] Furthermore, the secondary reactor can be a reaction vessel, a static balancer, or a dynamic reactor.

[0082] Furthermore, a static mixer can be installed between the temperature control device and the secondary reactor. The silicone oil, end-capping agent, and / or catalyst, after temperature adjustment, can be added to the static mixer and mixed evenly before being added to the secondary reactor for reaction.

[0083] Furthermore, a static mixer may be provided between the secondary reactor and the neutralization reactor. The silicone oil from the secondary reactor, along with the subsequently added neutralizing agent / inorganic neutralizing agent, can be mixed evenly in the static mixer before being added to the neutralization reactor for reaction.

[0084] Furthermore, when preparing silicone oils with lower molecular weights, the neutralization reactor can be connected to a descaling device. The material after the neutralization reaction can then undergo descaling to remove small molecules. The descaling device can be any device conventionally used in the art, such as a molecular evaporator.

[0085] Furthermore, when preparing the capping agent, the neutralization reactor can be connected to a filter. The material exiting the neutralization reactor can be filtered and then transported to the feed end, where it is mixed with the linear medium and catalyst before being fed into the falling film reactor for recycling in the reaction.

[0086] Fifthly, based on the self-feedback characteristics of the end-capping agent in the process of the present invention, the present invention also provides a self-feedback device for high-efficiency condensation polymerization of silicone oil in a cavity falling film reactor, including a static mixer, a falling film reactor, a temperature control device, a neutralization device, and an end-capping agent reaction device. The static mixer is connected to the upper feed inlet of the falling film reactor; the lower discharge outlet of the falling film reactor is connected to the temperature control device; the temperature control device is connected to one or more neutralization devices; and the temperature control device is also connected to one or more end-capping agent reaction devices.

[0087] The neutralization device is formed by connecting a neutralization reactor and a de-lowering device; the temperature control device is connected to the neutralization reactor.

[0088] The end-capping agent reaction device is composed of a secondary reactor, a neutralization reactor, and a filter connected in sequence; the temperature control device is connected to the secondary reactor.

[0089] The filter is connected to the static mixer.

[0090] Based on the self-feedback device of the present invention, the silicone oil prepared by the falling film reactor is diverted to a secondary reactor after the temperature is adjusted by the temperature control device. After secondary reaction, neutralization and filtration, a stable end-capping agent is obtained. Then, it is added to a static mixer and mixed with linear body and catalyst, and can be put back into the falling film reactor for production. This can realize the self-feedback of the end-capping agent, realize the continuity of production and better ensure the stability of the product.

[0091] Furthermore, the temperature control device can also be connected to one or more secondary reaction devices; the secondary reaction device is formed by sequentially connecting a secondary reactor, a neutralization reactor, and a de-lowering device; the temperature control device is connected to the secondary reactor.

[0092] Based on the apparatus of the present invention, the silicone oil prepared by the falling film reactor can be diverted to the secondary reaction device for reaction after the temperature is adjusted by the temperature control device. By adjusting the amount of capping agent, silicone oils with different molecular weights, low viscosity, high transparency, and low hydroxyl content can be obtained.

[0093] The above-mentioned diversions can all be carried out using conventional methods such as pipes and ball valves.

[0094] In a sixth aspect, the present invention also provides a self-feedback process for high-efficiency condensation polymerization of silicone oil using a cavity falling film reactor. The process involves mixing a linear polymer, a catalyst, and a capping agent, and then injecting the mixture into the reactor from the top to react and prepare silicone oil. A portion of the obtained silicone oil is diverted and reacted sequentially with a capping agent and a neutralizing agent, then filtered to obtain a capping agent, which is then mixed with the linear polymer and the catalyst and added to the falling film reactor for production.

[0095] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. This invention uses linear body as raw material and employs a cavity falling film reactor to achieve rapid reaction at high temperature while quickly removing water generated during the condensation process. Moreover, the production is continuous, greatly improving production efficiency. 2. The process of this invention uses an end-capping agent that is different from conventional small molecule end-capping agents, which overcomes the problem of end-capping agent loss caused by the high temperature and vacuum blowing environment of the cavity falling film reactor, and achieves efficient end-capping, so that the process of this invention can be implemented effectively and stably. 3. The process of this invention can synthesize macromolecular end-capping agents such as vinyl silicone oil, hydrogen-containing silicone oil, alkoxy silicone oil, and methyl silicone oil through self-feedback. The resulting end-capping agents are highly active, heat-resistant, low in hydroxyl groups, and have good batch-to-batch stability, ensuring product stability. The conversion rate of the end-capping agent can be improved when it is subsequently treated with end-capping agents. 4. This invention further employs modified linear phosphazene chloride as a catalyst, which effectively avoids the generation of a large number of cyclic compounds (D4, D5, etc.) while achieving high-efficiency reaction; 5. The process of this invention can be further processed using either a dynamic reactor or a static balancer, effectively improving the conversion rate of the end-capping agent, reducing costs, and obtaining silicone oil with low viscosity, high transparency, and low hydroxyl content; 6. The synthesis process based on the falling film reactor of this invention can synthesize silicone oil continuously, rapidly and efficiently, effectively solving the problems of cumbersome silicone oil synthesis process, low production efficiency, high energy consumption and poor batch stability of products in the existing technology. Attached Figure Description

[0096] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0097] Figure 1 This is a schematic diagram of the process flow of the present invention.

[0098] Figure 2 This is a schematic diagram of the self-feedback process flow of the present invention. Detailed Implementation

[0099] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, all materials involved in the following embodiments are commercially available. Unless otherwise specified, all methods described are conventional methods.

[0100] This invention provides a process for the efficient condensation polymerization of silicone oil using a cavity falling film method, wherein... Figure 1 This is a schematic diagram of the process flow of the present invention. Figure 2This is a schematic diagram of the self-feedback process flow of the present invention. The falling film reactor is typically arranged vertically, with the liquid forming a thin film flowing along the inner wall of the cavity. The cavity has a temperature control system, which allows for heat transfer to the liquid. Simultaneously, internal vacuum ventilation removes small molecules generated during production, a process commonly used in industrial processes for desulfurization. In this invention, the material undergoes rapid polymerization due to heating as it falls along the inner wall of the falling film reactor. The vacuum ventilation quickly removes the large amount of water rapidly generated during the linear polymerization reaction, and gravity-induced film falling allows the reaction to continue rapidly. Therefore, existing conventional falling film reactors can be used in this invention's process, and equipment with simple modifications to the interior of the cavity that does not affect the heat transfer, falling film, and vacuum ventilation functions required for the production process of this invention can also be used.

[0101] The following embodiments use a hinged falling film reactor as an example to implement the process of the present invention. Different types of falling film reactors do not affect their applicability to the process of the present invention.

[0102] The hydroxyl content of the silicone oils prepared in the following examples was tested by adding 1 wt% titanate (based on the mass of the silicone oil) to the silicone oil and letting it stand for 12 hours to observe whether gelation occurred. Example 1

[0103] A process for high-efficiency condensation polymerization of silicone oil using a cavity falling film method includes the following steps:

[0104] (1) The vinyl end-capping agent is prepared by the following steps: 100 parts by mass of linear phosphazene and 3 parts by mass of tetramethyldivinyldisiloxane are added to a reaction vessel, heated to 90°C, and the vacuum degree is maintained at -0.10~-0.05MPa. Then, 30 ppm of modified linear phosphazene chloride is added to the reaction system, and the reaction is carried out for 30 min. 0.45 parts by mass of sodium carbonate is added, and the reaction is neutralized for 30 min. The vinyl end-capping agent is obtained by filtration.

[0105] (2) The vinyl end-capping agent with a viscosity of 15 mm / s and the modified linear phosphazene chloride were pumped into a static mixer and mixed evenly. Then, the linear hydroxyl-terminated polydimethylsiloxane was mixed evenly in another static mixer. The mass ratio of the end-capping agent to the linear body was 3.2:100, and the amount of catalyst was 30 ppm.

[0106] (3) The above-mixed material is injected into the chamber-type falling film reactor from the top through the pressure valve to obtain the reaction product; wherein, in the falling film reactor, the vacuum degree is -0.10~-0.05MPa, the nitrogen bubbling speed is 0.2Kg / h, the oil temperature is 180℃, and the flow rate is controlled so that the material reacts in the reactor for 1-4min.

[0107] (4) The reaction product flows out from the bottom of the falling film reactor. After GPC testing, the linear conversion rate is 98.6%. It is then pumped into a heat exchanger, and the temperature is adjusted to 100°C. The silicone oil and tetramethyldivinyldisilazane after temperature adjustment are pumped into a static mixer at a mass ratio of 100:0.3 and mixed. The mixture is then reacted in a static balancer (or dynamic reactor) at 100°C for 35 minutes. Based on the amount of catalyst in the raw materials, the amount of neutralizing agent required is calculated. Then, tetramethyldivinyldisilazane is pumped into the static mixer. After mixing, the mixture was neutralized for 20 min at 100°C using a static balancing reactor (or a dynamic reactor). Then, at 190°C and under a vacuum of -0.10 to -0.05 MPa, the mixture was degraded using a molecular evaporator to obtain 3100 mm / s vinyl silicone oil with a yield of 96% and a cyclic content of 310 ppm. Hydroxyl content was tested by adding 1 wt% titanate (based on the mass of the silicone oil) to the silicone oil and allowing it to stand for 12 h to observe whether gelation occurred. The silicone oil obtained in this example had a low hydroxyl content and did not gel, meeting product requirements.

[0108] (5) Synthesis of the end-capping agent: After adjusting the temperature in a heat exchanger, the material is diverted and pumped into a mixture of tetramethyldivinyldisiloxane and catalyst-modified linear phosphazene chloride (material: mass ratio of tetramethyldivinyldisiloxane: modified linear phosphazene chloride is 100:15:0.004). After mixing in a static mixer, the mixture is reacted at 100°C in a static balancer (or dynamic reactor) for 30 min. The mixture flows into a stainless steel reactor. The amount of sodium carbonate is calculated by measuring the amount of catalyst in the silicone oil, and sodium carbonate is added. The neutralization reaction is carried out for 30 min. The mixture is then filtered to obtain the end-capping agent. The end-capping agent can be mixed with the catalyst in step (2) and recycled for production. Example 2

[0109] A process for high-efficiency condensation polymerization of silicone oil using a cavity falling film method includes the following steps:

[0110] (1) The vinyl end-capping agent is commercially available vinyl silicone oil.

[0111] (2) The vinyl end-capping agent with a viscosity of 15 mm / s and the modified linear phosphazene chloride were pumped into a static mixer and mixed evenly; then mixed evenly with the linear hydroxyl-terminated polydimethylsiloxane in another static mixer; the mass ratio of end-capping agent to linear body was 3.5:100, and the amount of catalyst was 20 ppm.

[0112] (3) The above-mentioned mixed material is fed into the cavity falling film reactor through the pressure preparation valve to obtain the reaction product; wherein, in the falling film reactor, the vacuum degree is -0.10~-0.05MPa, the nitrogen bubbling speed is 0.2Kg / h, the oil temperature is 180℃, and the flow rate is controlled so that the material reacts in the reactor for 1-4min.

[0113] (4) The reaction product flows out from the bottom of the falling film reactor. After GPC testing, the linear conversion rate is 97.6%. It is then pumped into a heat exchanger and the temperature is adjusted to 100°C. The silicone oil and tetramethyldivinyldisilazane after temperature adjustment are pumped into a static mixer at a mass ratio of 100:0.25 and mixed. The mixture is then reacted in a static balancer (or dynamic reactor) at 100°C for 30 min. Based on the amount of catalyst in the raw materials, the amount of neutralizing agent required is calculated and then the tetramethyldivinyldisilazane is pumped into the static mixer. After mixing, the mixture was neutralized for 20 minutes in a static equilibrator (or dynamic reactor) at 100°C. Then, at 190°C and a vacuum of -0.10 to -0.05 MPa, the mixture was degraded using a molecular evaporator to obtain 3500 mm / s vinyl silicone oil with a yield of 94% and a cyclic content of 600 ppm. Hydroxyl content detection: 1 wt% titanate (based on the mass of silicone oil) was added to the silicone oil and left for 12 hours to observe whether gelation occurred. The silicone oil obtained in this example had a low hydroxyl content and did not gel, meeting the product requirements.

[0114] (5) Synthesis of the end-capping agent: After adjusting the temperature in a heat exchanger, the material is diverted and pumped into tetramethyldivinyldisiloxane and catalyst-modified linear phosphazene chloride (material: tetramethyldivinyldisiloxane: modified linear phosphazene chloride mass ratio is 100:15:0.0035). After mixing in a static mixer, the mixture is reacted at 100°C in a static balancer (or dynamic reactor) for 40 min. The mixture flows into a stainless steel reactor. The amount of sodium carbonate is calculated by measuring the amount of catalyst in the silicone oil, and sodium carbonate is added. The neutralization reaction is carried out for 30 min. The mixture is then filtered to obtain the end-capping agent. The end-capping agent can be mixed with the catalyst in step (2) and recycled for production. Example 3

[0115] A process for high-efficiency condensation polymerization of silicone oil using a cavity falling film method includes the following steps:

[0116] (1) The methyl end-capping agent was prepared by the following steps: 100 parts by mass of linear phosphazene and 3.1 parts by mass of hexamethyldisiloxane were added to a reaction vessel, heated to 85°C, and the vacuum degree was maintained at -0.10~-0.05MPa. Modified linear phosphazene chloride was added, and the reaction was carried out for 30 min. 0.45 parts by mass of sodium carbonate were added, and the reaction was neutralized for 30 min. The methyl end-capping agent was obtained by filtration.

[0117] (2) The methyl end-capping agent with a viscosity of 15 mm / s and the modified linear phosphazene chloride were pumped into a static mixer and mixed evenly. Then, the linear hydroxyl-terminated polydimethylsiloxane was mixed evenly in another static mixer. The mass ratio of the end-capping agent to the linear body was 3.5:100, and the amount of catalyst was 40 ppm.

[0118] (3) The above-mentioned mixed material is injected into the cavity falling film reactor through the pressure valve. The vacuum degree is -0.10~-0.05MPa, the nitrogen bubbling speed is 0.2Kg / h, the oil temperature is 190℃, and the flow rate is controlled so that the material reacts in the reactor for 1-4min.

[0119] (4) The reaction product flows out from the bottom of the falling film reactor. After GPC testing, the linear conversion rate is 98.4%. It is pumped into the heat exchanger and the temperature is adjusted to 100°C. The silicone oil after temperature adjustment is pumped into the static mixer at a mass ratio of 100:2 and mixed. It is then reacted in the static balancer (or dynamic reactor) for 25 min. Based on the amount of catalyst in the raw materials, the amount of neutralizing agent required is calculated. Hexamethyldisilazane is then pumped in and mixed in the static mixer. It is then reacted in the static balancer (or dynamic reactor) at 100°C for 30 min. At 190°C and a vacuum degree of -0.10-0.05 MPa, it is de-lowered through a molecular evaporator to obtain 350 mm / s methyl silicone oil with a yield of 95% and a cyclic content of 320 ppm. Hydroxyl content detection: 1 wt% titanate (based on the mass of silicone oil) is added to the silicone oil and left for 12 h to observe whether gelation occurs. The silicone oil obtained in this example has a low hydroxyl content and does not gel, which meets the product requirements.

[0120] (5) Synthesis of the end-capping agent: After adjusting the temperature in a heat exchanger, the material is pumped into a separate pump containing hexamethyldisiloxane and catalyst-modified linear phosphazene chloride (material: hexamethyldisiloxane: modified linear phosphazene chloride mass ratio is 100:15:0.0045). After mixing in a static mixer, the mixture is reacted at 100°C in a static balancer (or dynamic reactor) for 30 min. The mixture then flows into a stainless steel reactor. The amount of sodium carbonate is calculated by measuring the amount of catalyst in the silicone oil, and sodium carbonate is added. The neutralization reaction is carried out for 30 min. The mixture is then filtered to obtain the end-capping agent. The end-capping agent can be recycled for production by mixing with the catalyst in step (2) through a pipeline. Example 4

[0121] A process for high-efficiency condensation polymerization of silicone oil using a cavity falling film method includes the following steps:

[0122] (1) The vinyl end-capping agent is prepared by the following steps: 100 parts by mass of linear phosphazene and 3 parts by mass of tetramethyldivinyldisiloxane are added to a reaction vessel, heated to 90°C, and the vacuum degree is maintained at -0.10~-0.05MPa. Then, 45 ppm of linear phosphazene chloride is added to the reaction system, and the reaction is carried out for 30 min. Then, 0.45 parts by mass of sodium carbonate is added, and the reaction is neutralized for 30 min. The vinyl end-capping agent is obtained by filtration.

[0123] (2) The vinyl end-capping agent with a viscosity of 15 mm / s and the linear phosphazene chloride are pumped into a static mixer and mixed evenly; then mixed evenly with the linear hydroxyl-terminated polydimethylsiloxane in another static mixer. The mass ratio of the end-capping agent to the linear body is 4:100, and the amount of catalyst is 40 ppm.

[0124] (3) The above-mentioned mixed material is fed into the cavity falling film reactor through the pressure preparation valve to obtain the reaction product; wherein, in the falling film reactor, the vacuum degree is -0.10~-0.05MPa, the nitrogen bubbling speed is 0.2Kg / h, the oil temperature is 180℃, and the flow rate is controlled so that the material reacts in the reactor for 1-4min.

[0125] (4) The reaction product flows out from the bottom of the falling film reactor. After GPC testing, the linear conversion rate is 97.8%. It is then pumped into a heat exchanger and the temperature is adjusted to 100°C. The silicone oil and tetramethyldivinyldisilazane after temperature adjustment are pumped into a static mixer at a mass ratio of 100:0.31 and mixed. The mixture is then reacted in a static balancer (or dynamic reactor) for 30 minutes. Based on the amount of catalyst in the raw materials, the amount of neutralizing agent required is calculated. Then, tetramethyldivinyldisilazane is pumped in and mixed in a static mixer. Then, at 100°C, the reaction was neutralized in a static balancing reactor (or dynamic reactor) for 25 min; at 190°C, under a vacuum of -0.10 to -0.05 MPa, the mixture was degraded using a molecular evaporator to obtain 3000 mm / s vinyl silicone oil with a yield of 90% and a cyclic content of 500 ppm; hydroxyl content detection: 1 wt% titanate (based on the mass of silicone oil) was added to the silicone oil and left for 12 h to observe whether gelation occurred. The silicone oil obtained in this example had a low hydroxyl content and did not gel, meeting the product requirements.

[0126] (5) Synthesis of the end-capping agent: After adjusting the temperature in a heat exchanger, the material is diverted and pumped into tetramethyldivinyldisiloxane and catalyst-modified linear phosphazene chloride (material: tetramethyldivinyldisiloxane: modified linear phosphazene chloride mass ratio is 100:15:0.005). After mixing in a static mixer, the mixture is reacted at 100°C in a static balancer (or dynamic reactor) for 30 min. The mixture flows into a stainless steel reactor. The amount of sodium carbonate is calculated by measuring the amount of catalyst in the silicone oil, and then sodium carbonate is added. The neutralization reaction is carried out for 30 min. The mixture is filtered to obtain the end-capping agent. The end-capping agent can be recycled for production by mixing with the catalyst in step (2) through a pipeline. Example 5

[0127] A process for high-efficiency condensation polymerization of silicone oil using a cavity falling film method includes the following steps:

[0128] (1) The hydrogen-containing end-capping agent was prepared by the following steps: 100 parts by mass of linear phosphazene and 2.5 parts by mass of tetramethyldisiloxane were added to a reaction vessel, heated to 60°C, and the vacuum degree was maintained at -0.10~-0.05MPa. Then, 45 ppm of linear phosphazene chloride was added to the reaction system, and the reaction was carried out for 30 min. Then, 0.45 parts by mass of sodium carbonate was added, and the reaction was neutralized for 30 min. The hydrogen-containing end-capping agent was obtained by filtration.

[0129] (2) The hydrogen-containing capping agent with a viscosity of 15 mm / and the linear phosphazene chloride are pumped into a static mixer and mixed evenly; then they are mixed evenly with the linear hydroxyl-capped polydimethylsiloxane in another static mixer. The mass ratio of capping agent to linear is 3.5:100, and the amount of catalyst is 40 ppm.

[0130] (3) The above-mentioned mixed material is fed into the cavity falling film reactor through the pressure preparation valve to obtain the reaction product; wherein, in the falling film reactor, the vacuum degree is -0.10~-0.05MPa, the nitrogen bubbling speed is 0.2Kg / h, the oil temperature is 180℃, and the flow rate is controlled so that the material reacts in the reactor for 1-4min.

[0131] (4) The reaction product flows out from the bottom of the falling film reactor. After GPC testing, the linear conversion rate is 97.9%. It is then pumped into a heat exchanger, and the temperature is adjusted to 60°C. The silicone oil and tetramethyldisiloxane after temperature adjustment are pumped into a static mixer at a mass ratio of 100:0.31 and mixed. The mixture is then reacted in a static balancer (or dynamic reactor) for 35 min. Based on the amount of catalyst in the raw materials, the amount of neutralizing agent required is calculated. Hexamethyldisilazine is then pumped in and mixed in a static mixer. The mixture is then reacted in a static balancer (or dynamic reactor) for 6 min. At 0°C, the reaction was neutralized in a static equilibrator (or dynamic reactor) for 20 min; then, at 190°C and a vacuum of -0.10 to -0.05 MPa, the mixture was degraded using a molecular evaporator to obtain a 3000 mm / s hydrogen-containing silicone oil with a yield of 94% and a cyclic content of 500 ppm. Hydroxyl content was tested by adding 1 wt% titanate (based on the mass of the silicone oil) to the silicone oil and allowing it to stand for 12 h to observe whether gelation occurred. The silicone oil obtained in this example had a low hydroxyl content and did not gel, meeting product requirements.

[0132] (5) Synthesis of the end-capping agent: After adjusting the temperature in a heat exchanger, the material is diverted and pumped into a mixture of tetramethyldisiloxane and catalyst-modified linear phosphazene chloride (material: tetramethyldisiloxane: modified linear phosphazene chloride mass ratio is 100:15:0.005). After mixing in a static mixer, the mixture is reacted at 60°C in a static balancer (or dynamic reactor) for 30 min. The mixture flows into a stainless steel reactor. The amount of sodium carbonate is calculated by measuring the amount of catalyst in the silicone oil, and sodium carbonate is added. The neutralization reaction is carried out for 30 min. The mixture is then filtered to obtain the end-capping agent. The end-capping agent can be recycled for production by mixing with the catalyst in step (2) through a pipeline. Example 6

[0133] A process for high-efficiency condensation polymerization of silicone oil using a cavity falling film method includes the following steps:

[0134] (1) The alkoxy end-capping agent was prepared by the following steps: 100 parts by mass of linear phosphazene and 2.8 parts by mass of vinyltrimethoxysilane were added to a reaction vessel, heated to 70°C, and the vacuum degree was maintained at -0.10~-0.05MPa. Then, 45 ppm of linear phosphazene chloride was added to the reaction system, and the reaction was carried out for 30 min. Then, 0.45 parts by mass of sodium carbonate was added, and the reaction was neutralized for 30 min. The alkoxy end-capping agent was obtained by filtration.

[0135] (2) The alkoxy end-capping agent with a viscosity of 15 mm / and the linear phosphazene chloride are pumped into a static mixer and mixed evenly; then mixed evenly with the linear hydroxyl-terminated polydimethylsiloxane in another static mixer. The mass ratio of the end-capping agent to the linear body is 3:100, and the amount of catalyst is 40 ppm.

[0136] (3) The above-mentioned mixed material is fed into the cavity falling film reactor through the pressure preparation valve to obtain the reaction product; wherein, in the falling film reactor, the vacuum degree is -0.10~-0.05MPa, the nitrogen bubbling speed is 0.2Kg / h, the oil temperature is 180℃, and the flow rate is controlled so that the material reacts in the reactor for 1-4min.

[0137] (4) The reaction product flows out from the bottom of the falling film reactor. After GPC testing, the linear conversion rate is 97.1%. It is pumped into the heat exchanger and the temperature is adjusted to 70°C. The silicone oil after temperature adjustment is pumped into the static mixer at a mass ratio of 100:0.31 and mixed. Then it is reacted in the static balancer (or dynamic reactor) for 30 min. According to the amount of catalyst in the raw materials, the amount of neutralizing agent required is calculated. Triethylamine is pumped in and mixed in the static mixer. Then it is reacted in the static balancer (or dynamic reactor) at 70°C for 30 min. At 190°C and a vacuum degree of -0.10~-0.05 MPa, it is de-lowered through the molecular evaporator to obtain 3000 mm / s alkoxy silicone oil with a yield of 96% and a cyclic content of 500 ppm.

[0138] (5) Synthesis of the end-capping agent: After adjusting the temperature in a heat exchanger, the material is diverted and pumped with vinyltrimethoxysilane and catalyst-modified linear phosphazene chloride (material: vinyltrimethoxysilane: modified linear phosphazene chloride mass ratio is 100:15:0.005). After mixing in a static mixer, the mixture is reacted at 70°C in a static balancer (or dynamic reactor) for 30 min. The mixture flows into a stainless steel reactor. The amount of sodium carbonate is calculated by measuring the amount of catalyst in the silicone oil, and sodium carbonate is added. The neutralization reaction is carried out for 30 min. The mixture is then filtered to obtain the end-capping agent. The end-capping agent can be recycled for production by mixing with the catalyst in step (2) through a pipeline. Comparative Example 1: Preparation of silicone oil from DMC (dimethylsiloxane mixed cyclic compound) via batch reactor

[0139] First, 4 tons of DMC are added to the dehydration reactor via the DMC intermediate storage tank. Steam is turned on, the temperature is raised to 55°C, and a vacuum is drawn while dry nitrogen is bubbled through the bottom. The dehydration time is 1.5 hours, and the amount removed is approximately 3% of the added DMC. The dehydrated DMC weighs 3880 kg (measured by a mass flow meter) and is then transferred to the DMC metering tank. 80 kg of end-capping agent (the low-viscosity vinyl silicone oil described in Example 1) is added to the end-capping agent metering tank. DMC, end-capping agent, and low-molecular-weight compounds are then added to the reaction vessel through their respective metering tanks. The reaction vessel is then opened. Stirring was performed, the heat transfer oil valve was opened, and the temperature was increased. When the temperature reached 120℃, 24g of potassium hydroxide alkali gel catalyst was added. The reaction temperature was controlled at 150℃, and the reaction time was 4 hours. After the reaction, 36g of phosphate ester gel neutralizer was added, and neutralization was carried out at 150℃ for 1 hour. According to GPC testing, the DMC conversion rate was 86%. After neutralization, vacuum distillation was performed. The de-lowering temperature during vacuum distillation was controlled at 170℃, the vacuum degree was 300Pa, and the de-lowering time was 4 hours when no liquid flowed out of the sight glass of the receiving tank, yielding vinyl silicone oil, of which 580 kg of low-boiling-point product was produced. The yield was 85%, and the cyclic content was 1500 ppm. 1wt% titanate ester (based on the mass of silicone oil) was added to the silicone oil and left for 12 hours to observe whether gelation occurred. The results showed that the silicone oil obtained in this comparative example had a high hydroxyl content and directly gelled, which is difficult to meet the requirements of practical applications. Comparative Example 2

[0140] A process for high-efficiency condensation polymerization of silicone oil using a cavity falling film method includes the following steps:

[0141] (1) The conventional small molecule capping agent hexamethyldisiloxane was used as the capping agent for the reaction.

[0142] (2) The small molecule capping agent and the modified linear phosphazene chloride are pumped into a static mixer and mixed evenly; then they are mixed evenly with the linear hydroxyl-capped polydimethylsiloxane in another static mixer. The mass ratio of the capping agent to the linear is 3:100, and the amount of catalyst is 40 ppm.

[0143] (3) The above-mentioned mixed material is injected into the cavity falling film reactor through the pressure valve for reaction. The vacuum degree is -0.10~-0.05MPa, the nitrogen bubbling speed is 0.2Kg / h, the oil temperature is 190℃, and the flow rate is controlled so that the material reacts in the reactor for 3min.

[0144] Because hexamethyldisiloxane has a low boiling point, a large amount of hexamethyldisiloxane is released under vacuum as the material is fed into the falling film reactor, resulting in significant losses during the synthesis process. Due to the rapid reaction rate and severe lack of end-capping agent, the end-capping process cannot be completed in time, resulting in silicone oil with excessively large molecular weight and viscosity, which cannot self-fall film and thus production cannot proceed.

[0145] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A process for high-efficiency condensation polymerization of silicone oil using a cavity falling film method, characterized in that: Using a falling film reactor as the reactor, linear polymer, catalyst A, and end-capping agent are mixed and injected into the reactor from the top to react, thus preparing silicone oil.

2. The process according to claim 1, characterized in that: The linear body is a hydroxyl-terminated polydimethylsiloxane; the capping agent includes at least one of methyl silicone oil, hydrogen-containing silicone oil, alkoxy silicone oil and vinyl silicone oil; the mass ratio of the linear body to the capping agent is 100:0.1-100:

15.

3. The process according to claim 1, characterized in that: The catalyst A comprises at least one of linear phosphazene chloride or modified phosphazene chloride; the amount of catalyst A is 10-100 ppm.

4. The process according to claim 1, characterized in that: The vacuum degree in the reactor is -0.10 to -0.05 MPa; the bubbling speed of the inert gas in the reactor is 0.1-2 kg / h; and the heat preservation temperature of the reactor is 100-200℃.

5. The process according to claim 1, characterized in that: The obtained silicone oil is reacted with a capping agent, then neutralized with a neutralizing agent, and degraded to obtain silicone oils of different molecular weights; or the obtained silicone oil is reacted with a capping agent and catalyst A, then neutralized with a neutralizing agent, filtered, and the capping agent suitable for the process described in claim 1 is obtained.

6. An apparatus for the process according to any one of claims 1-5, characterized in that: It includes a falling film reactor, a temperature control device, and a neutralization reactor connected in sequence; the temperature control device is connected to the lower outlet of the falling film reactor; the temperature control device is connected to one or more neutralization reactors respectively.

7. The apparatus according to claim 6, characterized in that: A secondary reactor is provided between the temperature control device and the neutralization reactor; the secondary reactor is a reaction vessel, a static balancer, or a dynamic reactor.

8. A self-feedback device for the process of high-efficiency condensation polymerization of silicone oil using cavity falling film as described in claim 1, characterized in that: It includes a static mixer, a falling film reactor, a temperature control device, a neutralization device, and a capping agent reaction device; wherein, the static mixer is connected to the upper inlet of the falling film reactor; the lower outlet of the falling film reactor is connected to the temperature control device; the temperature control device is connected to one or more neutralization devices; the temperature control device is also connected to one or more capping agent reaction devices. The neutralization device is formed by connecting a neutralization reactor and a de-lowering device; the temperature control device is connected to the neutralization reactor. The end-capping agent reaction device is composed of a secondary reactor, a neutralization reactor, and a filter connected in sequence; the temperature control device is connected to the secondary reactor; and the filter is connected to the static mixer.

9. The self-feedback device according to claim 8, characterized in that: The temperature control device is also connected to one or more secondary reaction devices; the secondary reaction devices are formed by sequentially connecting a secondary reactor, a neutralization reactor, and a de-lowering device; the temperature control device is connected to the secondary reactor.

10. A self-feedback process for high-efficiency condensation polymerization of silicone oil using a cavity-type falling film polymerization method, characterized in that... Using a falling film reactor as the reactor, linear polymer, catalyst, and end-capping agent are mixed and then pumped into the reactor from the top to react, thus preparing silicone oil. A portion of the obtained silicone oil is diverted and reacted sequentially with end-capping agent and neutralizing agent, then filtered to obtain end-capping agent, which is then mixed with linear polymer and catalyst and added back into the falling film reactor for recycling in production.

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