Production system of polyimide resin ultrafine powder

Abstract

The utility model discloses a production system of polyimide resin ultrafine powder. The production system comprises a dropwise adding tank, an amidation reaction kettle, an imidization reaction unit, a middle cooling kettle, a centrifugal machine and a drying box, the imidization reaction unit comprises 2-5 imidization reaction kettles which are connected in series, a condenser and a water segregator. The production system disclosed by the utility model can effectively control the molecular weight distribution and the particle size distribution of the polyimide resin, so that the polyimide resin ultrafine powder with narrow molecular weight distribution and narrow particle size distribution is prepared, and the polyimide resin powder prepared in advance in the prior art is abandoned; the preparation method has the advantages that the technical process is simplified, the product quality is improved, the market competitiveness of the product is enhanced, and the preparation method has a good popularization and application prospect.

Description

Technical Field

[0001] This utility model relates to a production system for polyimide resin ultrafine powder. Background Technology

[0002] Polyimide materials, due to their excellent high-temperature resistance, corrosion resistance, high strength and toughness, and low dielectric properties, have found increasingly widespread applications in aerospace, military, electronics, and nuclear fields with the advancement of technology. Among these, ultrafine polyimide resin powder, with its large specific surface area, strong adsorption, significant agglomeration, and active surface reactivity, shows promising application prospects in areas such as interlayer toughening of composite materials, resin modification, catalyst supports, photosensitive materials, pressure-sensitive materials, and powder metallurgy. It can also be widely used as a substitute for automotive parts, electronic components, metals and ceramics, and in other applications.

[0003] Since polyimide resin ultrafine powder is generally thermoplastic, there are many difficulties in actual production and processing.

[0004] Currently, the main methods for preparing polyimide resin ultrafine powder include emulsion reprecipitation, liquid-liquid phase separation, ultrasonic precipitation, suspension polymerization, and physical-aided methods. Although these methods can prepare a small number of microspheres, they all have problems such as low production capacity and difficulty in industrialization.

[0005] Polyimide resin is prepared by polycondensation reaction of equimolar dianhydride monomers and diamine monomers in an aprotic polar solvent. Since dianhydride monomers and diamine monomers are mostly rigid aromatic compounds, their polymerization products have poor solubility in solvents. A large amount of product precipitates during the reaction, making stirring difficult. If a specified amount of dianhydride monomers and diamine monomers are added at once, it is not conducive to the control of molecular weight and product particle size. Utility Model Content

[0006] The purpose of this invention is to solve the above problems and provide a production system for polyimide resin ultrafine powder.

[0007] The technical solution to achieve the purpose of this utility model is: a production system for polyimide resin ultrafine powder, including a dropping tank, an amidation reaction vessel, an imidization reaction unit, an intermediate cooling vessel, a centrifuge, and a drying oven.

[0008] The dripping tank is equipped with a dripping tank inlet, a dripping tank outlet, and a dripping tank air inlet and outlet.

[0009] The amidation reactor is equipped with an amidation inlet, an amidation outlet, an amidation gas inlet / outlet, an amidation dripping port, and an amidation stirrer; the amidation dripping port of the amidation reactor is connected to the outlet of the dripping tank.

[0010] The imidization reaction unit includes 2 to 5 imidization reaction vessels, a condenser, and a water separator connected in series.

[0011] Each imidization reactor is equipped with an imidization inlet, an imidization outlet, an imidization gas inlet / outlet, a solvent evaporation outlet, and an imidization stirrer; the first imidization reactor in series in the imidization reaction unit is also equipped with a solvent reflux outlet; the imidization inlet of the first imidization reactor in series in the imidization reaction unit is connected to the amidation outlet of the amidation reaction unit.

[0012] The condenser is provided with a solvent vapor inlet and a solvent condensate outlet; the solvent vapor inlet of the condenser is connected to the solvent evaporation port of each imidization reactor; the solvent condensate outlet of the condenser is connected to the solvent reflux port of the first imidization reactor in series in the imidization reaction unit via the water separator.

[0013] The intermediate cooling vessel is equipped with a cooling vessel inlet, a cooling vessel outlet, a cooling vessel inlet and outlet, and a cooling vessel stirrer; the cooling vessel inlet of the intermediate cooling vessel is connected to the imidization outlet of the last imidization reaction vessel connected in series in the imidization reaction unit.

[0014] The centrifuge is equipped with a centrifuge inlet and a centrifuge outlet. The centrifuge inlet is connected to the cooling vessel outlet of the intermediate cooling vessel. The centrifuge outlet is connected to the drying chamber via an auger conveyor.

[0015] The imidization stirrer is a serrated stirrer, consisting of a stirrer disc and several serrated blades arranged symmetrically along the edge of the stirrer disc.

[0016] The dropping tank, the amidation reactor, and the imideation reactor are all equipped with nitrogen protection systems.

[0017] The positive effects of this utility model are:

[0018] (1) The production system of this utility model adds a dropping tank to the amidation reactor to add part of the dianhydride or diamine monomer to control the molecular weight.

[0019] (2) The production system of this utility model adopts multiple imidization reactors connected in series to form an imidization reaction unit. The series reactor system can reduce the volume of a single imidization reactor and can make a certain gradient difference in water content between imidization reactors, or even between the upper and lower layers of materials in the imidization reactor, which is conducive to the discharge of water generated by the reaction and effectively accelerates the reaction process.

[0020] (3) The imidization reactor of the production system of this utility model adopts a serrated agitator. Combined with the relatively small volume of the imidization reactor, the serrated agitator can effectively play the role of dispersing and crushing materials, prevent the precipitated materials from agglomerating and clumping, and ensure the ultrafineness and narrow particle size distribution of polyimide resin powder.

[0021] (4) The production system of this utility model can effectively control the molecular weight distribution and particle size distribution of polyimide resin, thereby producing polyimide resin ultrafine powder with narrow molecular weight distribution and narrow particle size distribution. It eliminates the cumbersome steps of pre-preparing polyimide resin powder, crushing and sieving to obtain polyimide resin ultrafine powder in the existing process, simplifies the process, improves product quality, enhances the market competitiveness of the product, and has a good prospect for promotion and application. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the production system for polyimide resin ultrafine powder of this utility model.

[0023] Figure 2 This is a schematic diagram of the imidization reaction unit of this invention.

[0024] Figure 3 This is a schematic diagram of the sawtooth agitator of this utility model.

[0025] Figure 4 for Figure 3 Top view. Detailed Implementation

[0026] (Example 1)

[0027] See Figure 1 The production system for polyimide resin ultrafine powder in this embodiment includes a dropping tank 100, an amidation reactor 200, an imidization reaction unit 300, an intermediate cooling reactor 400, a centrifuge 500, and a drying oven 600.

[0028] The dripping tank 100 is provided with a dripping tank inlet 101, a dripping tank outlet 102, and a dripping tank air inlet / outlet 103.

[0029] The amidation reactor 200 is equipped with an amidation inlet 201, an amidation outlet 202, an amidation inlet / outlet 203, an amidation droplet 204, and an amidation stirrer 205. The amidation stirrer 205 is a conventional propeller-type stirrer. The amidation droplet 204 of the amidation reactor 200 is connected to the droplet outlet 102 of the droplet tank 100.

[0030] See Figure 1 and Figure 2The imidization reaction unit 300 in this embodiment consists of two imidization reaction vessels 310 connected in series, a condenser 320, and a water separator 330.

[0031] Each of the two series-connected imidization reactors 310 is equipped with an imidization inlet 311, an imidization outlet 312, an imidization gas inlet / outlet 313, a solvent evaporation outlet 314, and an imidization stirrer 315. The first series-connected imidization reactor 310 is also equipped with a solvent reflux outlet 316. The imidization inlet 311 of the first series-connected imidization reactor 310 is connected to the amidation outlet 202 of the amidation reactor 200.

[0032] The condenser 320 is provided with a solvent vapor inlet 321 and a solvent condensate outlet 322; the solvent vapor inlet 321 of the condenser 320 is connected to the solvent evaporation port 314 of each imidization reactor 310; the solvent condensate outlet 322 of the condenser 320 is connected to the solvent reflux port 316 on the first imidization reactor 310 in series via a water separator 330.

[0033] The imidization stirrer 315 is a serrated stirrer, and each imidization reactor 310 is equipped with two layers of serrated stirrers 315.

[0034] See Figure 3 and Figure 4 The serrated agitator 315 consists of an agitator disc 315-1 and several serrated blades 315-2 arranged symmetrically on the edge of the agitator disc 315-1.

[0035] Nitrogen protection systems are installed on the dropping tank 100, the amidation reactor 200, and each imidization reactor 310.

[0036] The intermediate cooling vessel 400 is equipped with a cooling vessel inlet 401, a cooling vessel outlet 402, a cooling vessel inlet / outlet 403, and a cooling vessel agitator 404. The cooling vessel agitator 404 is a conventional frame agitator. The cooling vessel inlet 401 of the intermediate cooling vessel 400 is connected to the imidization outlet 312 of the last imidization reaction vessel 310 connected in series.

[0037] Centrifuge 500 is a self-discharging centrifuge. Centrifuge 500 is equipped with centrifuge inlet 501 and centrifuge outlet 502. Centrifuge inlet 501 of centrifuge 500 is connected to cooling vessel outlet 402 of intermediate cooling vessel 400. Centrifuge outlet 502 of centrifuge 500 is connected to drying chamber 600 via auger conveyor 700.

[0038] The operation process of the polyimide resin ultrafine powder production system in this embodiment is as follows:

[0039] ① First, dissolve 5-10% of the total feed amount of dianhydride monomer (or diamine monomer) in a polar aprotic solvent and add it to the dropping tank 100 for later use.

[0040] Then, add the diamine monomer (or dianhydride monomer) and a polar aprotic solvent to the amidation reactor 200, and stir until the diamine monomer (or dianhydride monomer) is completely dissolved.

[0041] Next, 90-95% of the total feed amount of dianhydride monomer (or diamine monomer) is added to the amidation reactor 200, and the amidation reaction is carried out at room temperature for a period of time. Then, the dianhydride monomer in the dropping tank 100 is slowly added dropwise to the amidation reactor 200, and the amidation reaction is continued after the addition is completed.

[0042] ② After the amidation reaction is completed, a dehydrating agent is added to the amidation reactor 200, and then the reactants are sent to two imidation reactors 310 connected in series for imidation reaction. The solvent vapors generated by the two imidation reactors 310 are condensed and separated into water by the condenser 320 and the water separator 330, and then enter the first amidation reactor 310 connected in series to continue to participate in the reaction.

[0043] ③ After the imidization reaction is completed, the reactants are sent to an intermediate cooling kettle 400 for cooling and crystallization, then to a centrifuge 500 for centrifugal filtration and washing, and finally to a drying oven 600 via a screw conveyor 700 for drying, thus obtaining polyimide resin ultrafine powder.

Claims

1. A production system for ultrafine polyimide resin powder, characterized in that... It includes a dropping tank (100), an amidation reactor (200), an imidization reaction unit (300), an intermediate cooling reactor (400), a centrifuge (500), and a drying oven (600); The dripping tank (100) is provided with a dripping tank inlet (101), a dripping tank outlet (102), and a dripping tank air inlet / outlet (103). The amidation reactor (200) is provided with an amidation inlet (201), an amidation outlet (202), an amidation gas inlet / outlet (203), an amidation dripping inlet (204), and an amidation stirrer (205); the amidation dripping inlet (204) of the amidation reactor (200) is connected to the dripping tank outlet (102) of the dripping tank (100); The imidization reaction unit (300) includes 2 to 5 imidization reactors (310) connected in series, a condenser (320), and a water separator (330); each imidization reactor (310) is equipped with an imidization inlet (311), an imidization outlet (312), an imidization gas inlet / outlet (313), a solvent evaporation outlet (314), and an imidization stirrer (315); the first imidization reactor (310) connected in series in the imidization reaction unit (300) is also equipped with a solvent reflux outlet (316); the first imidization reactor (310) connected in series in the imidization reaction unit (300) The imidization inlet (311) is connected to the amidation outlet (202) of the amidation reactor (200); the condenser (320) is provided with a solvent vapor inlet (321) and a solvent condensate outlet (322); the solvent vapor inlet (321) of the condenser (320) is connected to the solvent evaporation port (314) of each imidization reactor (310); the solvent condensate outlet (322) of the condenser (320) is connected to the solvent reflux port (316) of the first imidization reactor (310) connected in series in the imidization reaction unit (300) via the water separator (330); The intermediate cooling vessel (400) is provided with a cooling vessel inlet (401), a cooling vessel outlet (402), a cooling vessel inlet / outlet (403), and a cooling vessel stirrer (404); the cooling vessel inlet (401) of the intermediate cooling vessel (400) is connected to the imidization outlet (312) of the last imidization reaction vessel (310) connected in series in the imidization reaction unit (300); The centrifuge (500) is provided with a centrifuge inlet (501) and a centrifuge outlet (502). The centrifuge inlet (501) of the centrifuge (500) is connected to the cooling vessel outlet (402) of the intermediate cooling vessel (400). The centrifuge outlet (502) of the centrifuge (500) is connected to the drying box (600) via an auger conveyor (700).

2. The production system for polyimide resin ultrafine powder according to claim 1, characterized in that: The imidization stirrer (315) is a serrated stirrer, consisting of a stirrer disc (315-1) and several serrated blades (315-2) arranged symmetrically on the edge of the stirrer disc (315-1).

3. The production system for polyimide resin ultrafine powder according to claim 1 or 2, characterized in that: The dropping tank (100), the amidation reactor (200), and the imideation reactor (310) are all equipped with nitrogen protection systems.

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