A spray precipitation apparatus for producing polyimide fine particles

Abstract

The utility model discloses a kind of spray settling equipment for preparing polyimide microfine particle, it is related to high polymer material preparation technical field. Including reaction kettle, reaction kettle is loaded with bad solvent, the inner chamber upper portion of reaction kettle is equipped with several high-pressure spray head, the inner chamber bottom of reaction kettle is equipped with stirrer;Wherein, high-pressure spray head is used to atomize and spray out polyimide slurry, stirrer is used to stir bad solvent and the polyimide microfine particle that settles out.This utility model atomizes slurry into microfine droplet by high-pressure spray head, greatly increase the contact specific surface area of slurry and bad solvent, so that solvent exchange is completed in very short time, ensure that the good solvent in slurry can be replaced by bad solvent quickly and effectively;By setting stirrer in the inner chamber bottom of reaction kettle, ensure that microfine particle is always in suspended and dispersed state during settling process, effectively prevent the agglomeration between particles, conducive to subsequent separation and drying.

Description

Technical Field

[0001] This utility model relates to the field of polymer material preparation technology, specifically to a spray sedimentation device for preparing polyimide microparticles. Background Technology

[0002] When polyimide (PI) resin is prepared by chemical imidization, polyimide is generally obtained by dehydrating polyamic acid (PAA) through chemical catalysis. This method is suitable for preparing soluble polyimide. In the traditional preparation process, polyimide slurry is first extruded from a hollow extrusion die to form solid liquid filaments. Then, the liquid filaments are settled in water or ethanol, which are unsuitable solvents for polyimide, and polyimide fibers are precipitated through solvent exchange.

[0003] However, when solid liquid filaments come into contact with unsuitable solvents, their surfaces harden rapidly, making it difficult for the good solvent at the center of the filament to exchange quickly and effectively with the unsuitable solvent. This makes it difficult to completely remove the good solvent at the center, which seriously affects the quality of the final polyimide resin. Utility Model Content

[0004] The main purpose of this invention is to provide a spray sedimentation device for preparing polyimide microparticles, so as to overcome the problems of low solvent exchange efficiency and product quality in solid liquid filaments in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A spray settling device for preparing polyimide microparticles includes a reaction vessel containing a poor solvent, a plurality of high-pressure nozzles in the upper part of the inner cavity of the reaction vessel, and a stirrer in the bottom of the inner cavity of the reaction vessel. The high-pressure nozzle is used to atomize and spray the polyimide slurry, and the stirrer is used to stir the poor solvent and the polyimide fine particles that have settled and precipitated.

[0006] Furthermore, a nozzle mounting ring for mounting the high-pressure nozzle is fixedly provided on the upper part of the inner cavity of the reactor. Multiple high-pressure nozzles are evenly arranged on the nozzle mounting ring along the axial direction, and the inner cavity of the nozzle mounting ring is connected to the high-pressure nozzle.

[0007] Furthermore, the inner cavity of the nozzle mounting ring is connected to a slurry tank outside the reactor via a slurry delivery pipe.

[0008] Furthermore, a gear pump for pressurization is provided on the slurry delivery pipe located between the slurry tank and the reactor.

[0009] Furthermore, a drive motor is provided below the reactor, and the output shaft of the drive motor passes through the bottom wall of the reactor and is connected to the stirrer.

[0010] Furthermore, a sealing element is provided at the connection between the output shaft of the drive motor and the bottom wall of the reactor to ensure the sealing of the reactor.

[0011] Furthermore, the stirring speed of the stirrer is 200 rpm to 1000 rpm.

[0012] Furthermore, the working pressure of the high-pressure nozzle is 3MPa-8MPa.

[0013] Compared with the prior art, the present invention has the following beneficial effects: Extremely high solvent exchange efficiency: The slurry is atomized into fine droplets by a high-pressure nozzle, which greatly increases the contact surface area between the slurry and the undesirable solvent, so that the solvent exchange is completed in a very short time, ensuring that the good solvent inside the slurry can be quickly and effectively replaced by the undesirable solvent. Preventing particle agglomeration: By installing a stirrer at the bottom of the inner cavity of the reactor, the fine particles are kept in a suspended and dispersed state during the settling process, which effectively prevents agglomeration between particles and facilitates subsequent separation and drying. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is a schematic diagram of the structure of the nozzle mounting ring and the high-pressure nozzle after assembly.

[0016] Figure 3 This is a schematic diagram of the high-pressure nozzle structure of this utility model.

[0017] Explanation of reference numerals in the attached diagram: 1. Reactor; 2. High-pressure nozzle; 3. Agitator; 4. Nozzle mounting ring; 5. Drive motor; 6. Slurry tank; 7. Gear pump; 8. Slurry delivery pipe. Detailed Implementation

[0018] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0019] Combination Figures 1 to 3 This embodiment provides a spray sedimentation device for preparing polyimide microparticles, including a reaction vessel 1 containing a poor solvent. The upper part of the inner cavity of the reaction vessel 1 is provided with several high-pressure nozzles 2, and the bottom of the inner cavity of the reaction vessel 1 is provided with a stirrer 3. The high-pressure nozzles 2 are used to atomize and spray the polyimide slurry, and the stirrer 3 is used to stir the poor solvent and the settled polyimide microparticles.

[0020] Specifically, reactor 1 holds the undesirable solvent and is used to receive atomized polyimide slurry. High-pressure nozzle 2 is used to atomize and spray the polyimide slurry, so that the slurry comes into direct contact with the undesirable solvent (such as water or ethanol) in reactor 1 in the form of extremely small droplets (micron-sized particles). Stirrer 3 is used to quickly and thoroughly stir the undesirable solvent / particle suspension to prevent the precipitated polyimide microparticles from agglomerating.

[0021] like Figure 1-2 As shown, in this embodiment, a nozzle mounting ring 4 for mounting high-pressure nozzles 2 is fixedly installed on the upper part of the inner cavity of the reactor 1. Multiple high-pressure nozzles 2 are evenly arranged on the nozzle mounting ring 4 along the axial direction, and the inner cavity of the nozzle mounting ring 4 is connected to the high-pressure nozzles 2.

[0022] like Figure 1 As shown, in this embodiment, the inner cavity of the nozzle mounting ring 4 is connected to the slurry tank 6 outside the reactor 1 via the slurry delivery pipe 8. A gear pump 7 for pressurization is provided on the slurry delivery pipe 8 located between the slurry tank 6 and the reactor 1.

[0023] like Figure 1 As shown, in this embodiment, a drive motor 5 is provided below the reactor 1. The output shaft of the drive motor 5 passes through the bottom wall of the reactor 1 and is connected to the stirrer 3. Specifically, a sealing element is provided at the connection between the output shaft of the drive motor 5 and the bottom wall of the reactor 1 to ensure the sealing of the reactor 1.

[0024] In this embodiment, the stirring speed of the agitator 3 is 200 rpm to 1000 rpm. The working pressure of the high-pressure nozzle 2 is 3 MPa to 8 MPa. The viscosity of the polyimide slurry is less than 10000 cp.

[0025] The solution in this embodiment provides a spray sedimentation device capable of efficiently removing good solvents and preparing high-quality polyimide microparticles. Through the high-pressure nozzle, it achieves extremely high solvent exchange efficiency and avoids central residue. Because the atomized particles are extremely small, the problem of "surface hardening and central residue" inherent in traditional solid liquid filaments is eliminated, thus ensuring the uniformity and high purity of the polyimide resin. The agitator configuration ensures that the microparticles remain in a suspended and dispersed state throughout the sedimentation process, effectively preventing particle agglomeration and facilitating subsequent separation and drying.

[0026] During operation, the polyimide slurry is atomized and sprayed out through the high-pressure nozzle 2, directly contacting the undesirable solvent in the reaction vessel 1, and quickly washing out to form polyimide microparticles. At the same time, the bottom agitator 3 is activated to prevent particle agglomeration.

[0027] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A spray settling device for preparing polyimide microparticles, characterized in that, The reactor includes a reaction vessel (1), which contains a poor solvent. The upper part of the inner cavity of the reaction vessel (1) is provided with several high-pressure nozzles (2), and the bottom of the inner cavity of the reaction vessel (1) is provided with a stirrer (3). The high-pressure nozzle (2) is used to atomize and spray the polyimide slurry, and the stirrer (3) is used to stir the poor solvent and the polyimide microparticles that have settled out.

2. The spray settling device for preparing polyimide microparticles as described in claim 1, characterized in that, The upper part of the inner cavity of the reactor (1) is fixedly provided with a nozzle mounting ring (4) for installing the high-pressure nozzle (2). Multiple high-pressure nozzles (2) are evenly arranged on the nozzle mounting ring (4) along the axial direction. The inner cavity of the nozzle mounting ring (4) is connected to the high-pressure nozzle (2).

3. The spray settling device for preparing polyimide microparticles as described in claim 2, characterized in that, The inner cavity of the nozzle mounting ring (4) is connected to the slurry tank (6) outside the reactor (1) through the slurry delivery pipe (8).

4. The spray settling device for preparing polyimide microparticles as described in claim 3, characterized in that, A gear pump (7) for pressurization is provided on the slurry delivery pipe (8) located between the slurry tank (6) and the reactor (1).

5. The spray settling device for preparing polyimide microparticles as described in claim 1, characterized in that, A drive motor (5) is provided below the reactor (1), and the output shaft of the drive motor (5) passes through the bottom wall of the reactor (1) and is connected to the stirrer (3).

6. The spray settling device for preparing polyimide microparticles as described in claim 5, characterized in that, The output shaft of the drive motor (5) is provided with a sealing element at the connection between it and the bottom wall of the reactor (1) to ensure the sealing of the reactor (1).

7. The spray settling device for preparing polyimide microparticles as described in claim 5, characterized in that, The stirring speed of the stirrer (3) is 200 rpm to 1000 rpm.

8. The spray settling device for preparing polyimide microparticles as described in claim 1, characterized in that, The working pressure of the high-pressure nozzle (2) is 3MPa-8MPa.

Images