Polymerization reaction kettle for preparing polyimide

Abstract

The invention discloses a polymerization reaction kettle for polyimide preparation, and relates to the technical field of polyimide preparation. The reaction kettle comprises a reaction kettle body, a rack is mounted in the center of the top of the reaction kettle body, a motor is mounted on the rack, the output end of the motor penetrates through the rack, extends into the reaction kettle body and is fixedly connected with a rotating shaft, stirring blades are fixedly connected to the outer surface of the rotating shaft, and a lower auxiliary material pipe is mounted at the bottom end of the rotating shaft. The flow guide groove is formed in the rotating shaft, and the sealing assembly is mounted at the bottom of the rotating shaft, so that one end of the auxiliary material feeding pipe is always positioned in the flow guide groove and is kept in a fixed state in the concentrated rotating process, and auxiliary materials are conveniently added into a solvent at the central position in the reaction kettle body and are diffused to the periphery; and auxiliary materials are fed from the periphery of the reaction kettle body by utilizing a plurality of upper auxiliary material pipes and are diffused to the center, so that the diffusion uniformity of the auxiliary materials is improved, and the reaction rate is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of polyimide preparation, in particular to a polymerization reaction kettle for preparing polyimide. Background Art

[0002] Polyimide is a high-performance polymer that requires the use of a reactor during its preparation. During the synthesis and polymerization of the polyimide precursor, the dianhydride and diamine monomers need to be dissolved in a solvent, and appropriate amounts of catalysts and accelerators are added, and the polymerization reaction is caused by heating and stirring.

[0003] The reactor can provide a closed environment for the preparation of polyimide, and can control the concentration, temperature, reaction time and stirring rate of the reactants to ensure the smooth progress of the polymerization reaction. When adding dianhydride and diamine to the solvent in the reactor through the injection port of the reactor, the traditional addition process is to add them directly to the solvent in the reactor. Therefore, it is necessary to cooperate with the stirring blade in the reactor to mix the dianhydride and diamine placed on the upper surface of the solvent into the solvent. However, when adding dianhydride and diamine from above, the dianhydride and diamine will fall quickly under the action of gravity, and the stirring blade is mainly used to stir the dianhydride and diamine. If the existing liquid in the reactor is stirred, it is difficult for the newly added and rapidly falling dianhydride and diamine to fully contact and drive their dispersion in the initial stage. At the same time, since the addition points of dianhydride and diamine are at the top or close to the inner wall of the reactor, high concentration areas are easily formed locally. Even if the stirring blades are working, these locally concentrated dianhydrides and diamines need to be dispersed in a small range first before they can be further mixed with the solvent in the entire reactor, resulting in a relatively slow mixing reaction process. For this reason, we propose a polymerization reactor for the preparation of polyimide. Summary of the invention

[0004] The object of the present invention is to provide a polymerization reactor for preparing polyimide to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: A polymerization reactor for preparing polyimide, comprising:

[0006] A reactor body, wherein a frame is installed at the top center of the reactor body, a motor is installed on the frame, an output end of the motor passes through the frame and extends to the inside of the reactor body and is fixedly connected to a rotating shaft, a stirring blade is fixedly connected to the outer surface of the rotating shaft, a lower auxiliary material pipe is installed at the bottom end of the rotating shaft, a guide groove is opened inside the rotating shaft, and a sealing component is installed between the guide groove and the lower auxiliary material pipe;

[0007] An auxiliary material injection assembly, the auxiliary material injection assembly is installed at the bottom end of the lower auxiliary material pipe;

[0008] A plurality of nozzle assemblies are installed on the outer surface of the rotating shaft, and the nozzle assemblies are connected with the guide groove and conduct unidirectional flow along the guide groove.

[0009] Furthermore, a feed pipe and an upper auxiliary material pipe are fixedly installed on the top of the reactor, the lower end of the upper auxiliary material pipe penetrates the reactor body and extends into the reactor body, and the outer side of the upper auxiliary material pipe is in contact with the inner wall of the reactor body.

[0010] Furthermore, a first mounting groove for mounting a sealing assembly is formed at the bottom end of the rotating shaft, and a second mounting groove for mounting a nozzle assembly is formed on the inner wall of the guide groove.

[0011] Further, the sealing assembly includes a chassis and a double V-shaped sealing sleeve, the double V-shaped sealing sleeve is movably mounted on the chassis, and the chassis is fixedly mounted in a first mounting groove at the bottom of the rotating shaft;

[0012] A third mounting groove is provided on the inner side of the chassis, a bottom ring is fixedly installed on the bottom of the double V-shaped sealing sleeve, a top ring is fixedly installed on the top of the double V-shaped sealing sleeve, a sealing bearing is inserted in the top ring, and the bottom ring is inserted in the third mounting groove;

[0013] The double V-shaped sealing sleeve is made of acid and alkali resistant rubber material.

[0014] Furthermore, the auxiliary material injection assembly includes a waste discharge connecting pipe detachably installed at the bottom end of the lower auxiliary material pipe, and two first side tubes are fixedly installed at the bottom end of the lower auxiliary material pipe, the two first side tubes are placed outside the reactor body, and the free ends of the two first side tubes are respectively detachably installed with auxiliary material connecting pipes.

[0015] Furthermore, a sealing ring is fixedly installed on the top of the waste discharge connecting pipe and the top of the auxiliary material connecting pipe, a connecting nut is arranged on the outside of the sealing ring, a sleeve groove is opened in the connecting nut, and the connecting nut is inserted and installed on the corresponding waste discharge connecting pipe or auxiliary material connecting pipe through the sleeve groove;

[0016] A flow guide pipe is fixedly connected between the waste discharge connecting pipe and the two auxiliary material connecting pipes.

[0017] Furthermore, a waste discharge solenoid valve is fixedly installed at one end of the waste discharge connecting pipe away from the lower auxiliary material pipe, an auxiliary material injection solenoid valve is fixedly installed at one end of the auxiliary material connecting pipe away from the first side pipe, and the end of the auxiliary material injection solenoid valve away from the first side pipe is connected to an external auxiliary material delivery pump through a pipeline, and the end of the waste discharge solenoid valve away from the waste discharge connecting pipe is connected to an external waste discharge pump through a pipeline.

[0018] Furthermore, a second side tube is fixedly installed on the outer side wall of the lower auxiliary material tube, a ventilation solenoid valve is fixedly installed on one end of the second side tube, and an air filter element is threadedly connected to one end of the ventilation solenoid valve away from the second side tube.

[0019] Further, the nozzle assembly includes an outer shell threadedly connected to the inside of the second mounting groove, a sealing groove is opened at one end of the outer shell, a support sleeve is installed at one end of the outer shell, a push rod is coaxially installed inside the support sleeve, a sealing ball is fixedly connected to one end of the push rod away from the guide groove, and the other end of the push rod passes through the support sleeve and is fixedly installed with a gasket.

[0020] Furthermore, an elastic member is sleeved on the outer surface of the push rod, one end of the elastic member is connected to the supporting sleeve shell, and the other end is connected to the cushion block.

[0021] The present invention has at least the following beneficial effects:

[0022] 1. The present invention opens a guide groove in the rotating shaft and installs a sealing component at the bottom of the rotating shaft, so that one end of the lower auxiliary material pipe is always located in the guide groove and remains fixed during the rotation process, which is convenient for cooperating with the lower auxiliary material pipe, the first side pipe, the auxiliary material connecting pipe, the auxiliary material injection solenoid valve, and the components to add auxiliary materials to the solvent at the center position of the reactor body and diffuse it to the surroundings, and then use the multiple upper auxiliary material pipes to inject auxiliary materials from the surroundings of the reactor body and diffuse them to the center, which is convenient for improving the uniformity of auxiliary material diffusion, thereby further improving the reaction rate.

[0023] 2. The present invention can make the auxiliary material flow unidirectionally from the guide groove to the inside of the reactor body through the mutual cooperation of the sealing ball, support sleeve, push rod, cushion block and elastic member, and isolate the guide groove from the inner cavity of the reactor body without pressurization to avoid the backflow of external solvent; at the same time, in conjunction with the second side pipe, ventilation solenoid valve, waste discharge connecting pipe and waste discharge solenoid valve, the auxiliary material remaining in the nozzle assembly, the guide groove and the lower auxiliary material pipe can be discharged to prevent the auxiliary material from remaining for a long time and causing qualitative change, thereby ensuring the injection quality of the auxiliary material in subsequent production.

[0024] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a three-dimensional schematic diagram of the overall structure of the present invention;

[0026] Figure 2 It is a cross-sectional view of the reactor body structure of the present invention;

[0027] Figure 3 For the present invention Figure 2 The enlarged view of point A in the middle;

[0028] Figure 4 It is an exploded schematic diagram of the sealing component structure in the present invention;

[0029] Figure 5 is a cross-sectional schematic diagram of the nozzle assembly of the present invention;

[0030] Figure 6 It is a three-dimensional schematic diagram of the auxiliary material injection component in the present invention;

[0031] Figure 7 It is a cross-sectional schematic diagram of the waste discharge connecting pipe and the auxiliary material connecting pipe in the present invention.

[0032] Reference numerals:

[0033] 1. Reactor body; 2. Frame; 3. Motor; 4. Rotating shaft; 5. Stirring blade; 6. Lower auxiliary material pipe; 7. Guide groove; 8. Sealing assembly; 81. Chassis; 82. Double V-shaped sealing sleeve; 83. Third mounting groove; 84. Bottom ring; 85. Top ring; 86. Sealing bearing; 9. Auxiliary material injection assembly; 91. Waste discharge connecting pipe; 92. First side pipe; 93. Auxiliary material connecting pipe; 94. Sealing ring; 95. Connecting nut; 96. Sleeve groove; 97. Guide pipe; 98. Waste discharge solenoid valve; 99. Auxiliary material injection solenoid valve; 10. Nozzle assembly; 101. Shell; 102. Sealing groove; 103. Support sleeve; 104. Push rod; 105. Sealing ball; 106. Pad; 107. Elastic member; 11. Feed pipe; 12. Upper auxiliary material pipe; 13. First mounting groove; 14. Second mounting groove; 15. Second side pipe; 16. Ventilation solenoid valve. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0035] See also Figure 1-Figure 7 The present invention provides a technical solution: a polymerization reactor for preparing polyimide, comprising:

[0036] A reactor body 1 is provided with a frame 2 at the top center of the reactor body 1, a motor 3 is provided on the frame 2, an output end of the motor 3 passes through the frame 2 and extends to the inside of the reactor body 1 and is fixedly connected with a rotating shaft 4, a stirring blade 5 is fixedly connected to the outer surface of the rotating shaft 4, a lower auxiliary material pipe 6 is provided at the bottom end of the rotating shaft 4, a guide groove 7 is provided inside the rotating shaft 4, and a sealing component 8 is provided between the guide groove 7 and the lower auxiliary material pipe 6;

[0037] Auxiliary material injection assembly 9, the auxiliary material injection assembly 9 is installed at the bottom end of the lower auxiliary material pipe 6;

[0038] A plurality of nozzle assemblies 10 are installed on the outer surface of the rotating shaft 4, and the nozzle assemblies 10 are connected with the guide groove 7 and conduct unidirectional flow along the guide groove.

[0039] According to the technical solution of this embodiment, a feed pipe 11 and a plurality of upper auxiliary material pipes 12 are fixedly installed on the top of the reactor. The lower ends of the upper auxiliary material pipes 12 penetrate the reactor body 1 and extend into the reactor body 1, and the outer sides of the upper auxiliary material pipes 12 are in contact with the inner wall of the reactor body 1. The feed pipe 11 is provided to facilitate adding solvent into the reactor body 1, and the upper auxiliary material pipes 12 are provided to facilitate adding auxiliary materials to the solvent near the inner wall of the reactor body 1 from top to bottom.

[0040] According to the technical solution of this embodiment, a first mounting groove 13 for installing the sealing assembly 8 is opened at the bottom end of the rotating shaft 4, and a second mounting groove 14 for installing the nozzle assembly 10 is opened on the inner wall of the guide groove 7. The first mounting groove 13 and the second mounting groove 14 are used to provide a channel basis for the injection and discharge of auxiliary materials.

[0041] According to the technical solution of this embodiment, a plurality of ear seats are installed on the outside of the reactor body 1, and a controller (not shown in the figure) is also arranged outside the reactor body 1, and the motor 3 is electrically connected to the controller.

[0042] Furthermore, if Figure 4 As shown, the sealing assembly 8 includes a chassis 81 and a double V-shaped sealing sleeve 82. The double V-shaped sealing sleeve 82 is made of acid and alkali resistant rubber material. The double V-shaped sealing sleeve 82 is movably mounted on the chassis 81, and the chassis 81 is fixedly mounted in the first mounting groove 13 at the bottom of the rotating shaft 4. A third mounting groove 83 is provided on the inner side of the chassis 81. A bottom ring 84 is fixedly mounted on the bottom of the double V-shaped sealing sleeve 82, and a top ring 85 is fixedly mounted on the top of the double V-shaped sealing sleeve 82. A sealing bearing 86 is inserted and installed in the top ring 85. The sealing bearing 86 is fixedly connected to the lower auxiliary material pipe 6, and the bottom ring 84 is inserted and installed in the third mounting groove 83. Through the provision of the double V-shaped sealing sleeve 82, one end of the lower auxiliary material pipe 6 can extend through the double V-shaped sealing sleeve 82 to the guide groove 7, and provide sealing for the space in the guide groove 7 to avoid leakage of auxiliary materials, and can also ensure that the lower auxiliary material pipe 6 remains in a fixed state when the rotating shaft 4 rotates.

[0043] It should be noted that the bottom end of the lower auxiliary material pipe 6 passes through the reactor body 1 , and the reactor body 1 is fixedly connected to maintain the stability of the lower auxiliary material pipe 6 .

[0044] According to the technical solution of this embodiment, the auxiliary material injection assembly 9 includes a waste discharge connecting pipe 91 detachably installed at the bottom end of the lower auxiliary material pipe 6, and two first side tubes 92 are fixedly installed at the bottom end of the lower auxiliary material pipe 6. The two first side tubes 92 are placed outside the reactor body 1, and the free ends of the two first side tubes 92 are respectively detachably installed with auxiliary material connecting pipes 93. The set auxiliary material connecting pipes 93 are used to facilitate the input of auxiliary materials into the lower auxiliary material pipe 6.

[0045] Furthermore, sealing rings 94 are fixedly installed on the top of the waste discharge connecting pipe 91 and the top of the auxiliary material connecting pipe 93, and a connecting nut 95 is arranged on the outside of the sealing ring 94. A sleeve groove 96 is opened in the connecting nut 95, and the connecting nut 95 is inserted and installed on the corresponding waste discharge connecting pipe 91 or the auxiliary material connecting pipe 93 through the sleeve groove 96. The provided sealing ring 94 and connecting nut 95 can enhance the connection sealing between the waste discharge connecting pipe 91 and the lower auxiliary material pipe 6, and between the auxiliary material connecting pipe 93 and the first side pipe 92, so as to avoid leakage of auxiliary materials.

[0046] Furthermore, a waste discharge solenoid valve 98 is fixedly installed at one end of the waste discharge connecting pipe 91 away from the lower auxiliary material pipe 6, and an auxiliary material injection solenoid valve 99 is fixedly installed at one end of the auxiliary material connecting pipe 93 away from the first side pipe 92. The waste discharge solenoid valve 98 and the auxiliary material injection solenoid valve 99 are respectively electrically connected to an external controller through connecting lines, and the end of the auxiliary material injection solenoid valve 99 away from the first side pipe 92 is connected to the auxiliary material delivery pump through a pipeline, and the end of the waste discharge solenoid valve 98 away from the waste discharge connecting pipe 91 is connected to the waste discharge pump through a pipeline.

[0047] According to the technical solution of this embodiment, a second side tube 15 is fixedly installed on the outer wall of the lower auxiliary material tube 6, a ventilation solenoid valve 16 is fixedly installed at one end of the second side tube 15, and an air filter element is threadedly connected to one end of the ventilation solenoid valve 16 away from the second side tube 15, so as to filter the external gas entering the ventilation solenoid valve 16 and prevent external impurities from entering.

[0048] Furthermore, a guide pipe 97 is fixedly connected between the waste discharge connecting pipe 91 and the two auxiliary material connecting pipes 93. By utilizing the provided guide pipe 97, the auxiliary materials remaining in the two auxiliary material connecting pipes 93 can flow from the guide pipe 97 into the waste discharge connecting pipe 91. When there are residual auxiliary materials in the guide groove 7 and the lower auxiliary material pipe 6, the second side pipe 15, the ventilation solenoid valve 16 and the waste discharge connecting pipe 91 can be cooperated to discharge the residual auxiliary materials, so as to ensure the auxiliary material injection quality in subsequent production.

[0049] According to the technical solution of this embodiment, the nozzle assembly 10 includes an outer shell 101 threadedly connected to the inside of the second mounting groove 14, a sealing groove 102 is opened at one end of the outer shell 101, a supporting sleeve 103 is installed at one end inside the outer shell 101, a push rod 104 is coaxially installed inside the supporting sleeve 103, and a sealing ball 105 is fixedly connected to the end of the push rod 104 away from the guide groove, and a cushion block 106 is fixedly installed at the other end of the push rod 104. Through the arrangement of the nozzle and the sealing ball 105, the function of one-way input of auxiliary materials in the guide groove 7 can be realized, so that auxiliary materials can be added to the solvent located at the center position of the reactor body 1, thereby improving the mixing quality and reaction efficiency of the auxiliary materials and the solvent.

[0050] Furthermore, an elastic member 107 is sleeved on the outer surface of the push rod 104, one end of the elastic member 107 is connected to the support sleeve 103, and the other end is connected to the cushion block 106. The elastic member 107 is used to facilitate the reset of the push rod 104 and the sealing ball 105 to avoid the backflow of the solvent inside the reactor body 1.

[0051] It should be noted that when adding auxiliary materials, the lower auxiliary material pipe 6 and the nozzle assembly 10 can be used to spray the auxiliary materials from the center of the reactor to the surroundings and diffuse them to the surroundings, and the multiple upper auxiliary material pipes 12 can be used to input auxiliary materials from the surroundings of the reactor body 1 and diffuse them to the center. In this way, the uniformity of the auxiliary material diffusion can be improved, thereby further improving the reaction rate.

[0052] The use principle and process of the present invention are as follows: when a reaction is required, the solvent is first injected into the reactor body 1 through the feed pipe 11. Then, when adding auxiliary materials, the auxiliary materials are first added from the periphery of the reactor body 1 through the upper auxiliary material pipe 12 and diffused toward the center. At the same time, the two auxiliary material injection solenoid valves 99 are opened through an external controller. At this time, the ventilation solenoid valve 16 and the exhaust solenoid valve 98 are closed, thereby starting the externally connected delivery pump to squeeze the auxiliary materials into the first side pipe 92, and then the two auxiliary materials are injected into the lower auxiliary material pipe 6 through the first side pipe 92 and the auxiliary material connecting pipe 93, and then the auxiliary materials are injected into the lower auxiliary material pipe 6 through the lower auxiliary material pipe 6. The auxiliary material pipe 6 is injected into the guide groove 7. At this time, the auxiliary material in the guide groove 7 is pressurized and diverted to the shells 101 of the multiple nozzle assemblies 10, and the pad 106 and the sealing ball 105 are pushed, so that the pad 106 compresses the compression spring to the side of the support shell 103. At the same time, the sealing ball 105 is separated from the sealing groove 102. Therefore, the auxiliary material entering the nozzle is sprayed into the solvent near the center of the reactor body 1 through the nozzle, and the rotating stirring blade 5 can realize the two-way auxiliary material addition, thereby improving the mixing reaction efficiency of the solvent and the auxiliary material and shortening the production cycle;

[0053] When there is no need to add auxiliary materials, the external delivery pump is turned off. At this time, the auxiliary materials in the seal no longer have pressure, so that the elastic member 107 stretches and rebounds, and then the elastic member 107 pushes the cushion block 106 to reset to one side, so that the cushion block 106 pulls the sealing ball 105 back into the sealing groove 102 through the push rod 104, so that the nozzle assembly 10 is isolated from the inner cavity of the reactor body 1, and then, the two auxiliary material injection solenoid valves 99 are closed. At this time, the waste discharge solenoid valve 98 and the ventilation solenoid valve 16 are opened, so that the lower auxiliary material pipe 6 and the guide groove 7 are no longer in a negative pressure state, so that the external waste discharge pump can cooperate to extract the residual auxiliary materials in the guide groove 7 and the lower auxiliary material pipe 6.

[0054] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0055] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. When an element is referred to as being "assembled on", "installed on", "fixed on" or "set on" another element, it can be directly on the other element or there can also be a centered element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a centered element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and are not intended to be the only implementation method.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0057] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Claims

1. A polymerization reactor for preparing polyimide, characterized in that: include: A reactor body (1), wherein a frame (2) is installed at the top center of the reactor body (1), a motor (3) is installed on the frame (2), an output end of the motor (3) passes through the frame (2) and extends into the interior of the reactor body (1) and is fixedly connected to a rotating shaft (4), a stirring blade (5) is fixedly connected to the outer surface of the rotating shaft (4), a lower auxiliary material pipe (6) is installed at the bottom end of the rotating shaft (4), a guide groove (7) is provided inside the rotating shaft (4), and a sealing component (8) is installed between the guide groove (7) and the lower auxiliary material pipe (6); An auxiliary material injection assembly (9), the auxiliary material injection assembly (9) being installed at the bottom end of the lower auxiliary material pipe (6); A plurality of nozzle assemblies (10) are mounted on the outer surface of the rotating shaft (4), and the nozzle assemblies (10) are connected to the guide groove (7) and conduct unidirectional flow along the guide groove.

2. A polymerization reactor for preparing polyimide according to claim 1, characterized in that: A feed pipe (11) and an upper auxiliary material pipe (12) are fixedly installed on the top of the reactor. The lower end of the upper auxiliary material pipe (12) passes through the reactor body (1) and extends into the reactor body (1), and the outer side of the upper auxiliary material pipe (12) is in contact with the inner wall of the reactor body (1).

3. A polymerization reactor for preparing polyimide according to claim 2, characterized in that: A first mounting groove (13) for mounting a sealing assembly (8) is provided at the bottom end of the rotating shaft (4), and a second mounting groove (14) for mounting a nozzle assembly (10) is provided on the inner wall of the guide groove (7).

4. A polymerization reactor for preparing polyimide according to claim 3, characterized in that: The sealing assembly (8) comprises a chassis (81) and a double V-shaped sealing sleeve (82), wherein the double V-shaped sealing sleeve (82) is movably mounted on the chassis (81), and the chassis (81) is fixedly mounted in a first mounting groove (13) at the bottom of the rotating shaft (4); A third mounting groove (83) is provided on the inner side of the bottom plate (81); a bottom ring (84) is fixedly installed on the bottom of the double V-shaped sealing sleeve (82); a top ring (85) is fixedly installed on the top of the double V-shaped sealing sleeve (82); a sealing bearing (86) is inserted into the top ring (85); and the bottom ring (84) is inserted into the third mounting groove (83); The double V-shaped sealing sleeve (82) is made of acid and alkali resistant rubber material.

5. A polymerization reactor for preparing polyimide according to claim 4, characterized in that: The auxiliary material injection assembly (9) comprises a waste discharge connecting pipe (91) detachably mounted on the bottom end of the lower auxiliary material pipe (6), and two first side pipes (92) are fixedly mounted on the bottom end of the lower auxiliary material pipe (6), the two first side pipes (92) are placed outside the reactor body (1), and the free ends of the two first side pipes (92) are detachably mounted with auxiliary material connecting pipes (93).

6. A polymerization reaction kettle for preparing polyimide according to claim 5, characterized in that: A sealing ring (94) is fixedly installed on the top of the waste discharge connecting pipe (91) and the top of the auxiliary material connecting pipe (93); a connecting nut (95) is arranged on the outside of the sealing ring (94); a sleeve groove (96) is provided in the connecting nut (95); and the connecting nut (95) is inserted and installed on the corresponding waste discharge connecting pipe (91) or the auxiliary material connecting pipe (93) through the sleeve groove (96); A flow guide pipe (97) is fixedly connected between the waste discharge connecting pipe (91) and the two auxiliary material connecting pipes (93), respectively.

7. A polymerization reactor for preparing polyimide according to claim 6, characterized in that: A waste discharge solenoid valve (98) is fixedly installed at one end of the waste discharge connecting pipe (91) away from the lower auxiliary material pipe (6), and an auxiliary material injection solenoid valve (99) is fixedly installed at one end of the auxiliary material connecting pipe (93) away from the first side pipe (92), and the end of the auxiliary material injection solenoid valve (99) away from the first side pipe (92) is connected to an external auxiliary material delivery pump through a pipeline, and the end of the waste discharge solenoid valve (98) away from the waste discharge connecting pipe (91) is connected to an external waste discharge pump through a pipeline.

8. A polymerization reaction kettle for preparing polyimide according to claim 7, characterized in that: A second side tube (15) is fixedly mounted on the outer side wall of the lower auxiliary material tube (6); a ventilation solenoid valve (16) is fixedly mounted on one end of the second side tube (15); and an air filter element is threadedly connected to one end of the ventilation solenoid valve (16) away from the second side tube (15).

9. A polymerization reactor for preparing polyimide according to claim 7, characterized in that: The nozzle assembly (10) comprises a shell (101) threadedly connected to the inside of the second installation groove (14); a sealing groove (102) is provided at one end of the shell (101); a support sleeve (103) is installed at one end inside the shell (101); a push rod (104) is coaxially installed inside the support sleeve (103); a sealing ball (105) is fixedly connected to one end of the push rod (104) away from the guide groove; and a cushion block (106) is fixedly installed at the other end of the push rod (104) passing through the support sleeve (103).

10. A polymerization reactor for preparing polyimide according to claim 9, characterized in that: An elastic member (107) is sleeved on the outer surface of the push rod (104); one end of the elastic member (107) is connected to the supporting sleeve (103), and the other end is connected to the cushion block (106).

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