阅读说明：本技术 一种使用撞击流反应器制备聚酰亚胺前驱体及其薄膜的制备方法 (Preparation method for preparing polyimide precursor and film thereof by using impinging stream reactor ) 是由 肖桂林 陈诚 朱双全 鲁丽平 于 2021-02-04 设计创作，主要内容包括：本发明公开一种聚酰亚胺前驱体聚酰胺酸溶液及其薄膜的制备方法。本发明方法制备的聚酰亚胺前驱体是将含芳香结构的酸二酐A的乳液和含芳香结构的二胺B的溶液或乳液混合,利用撞击流反应器在撞击流作用下,通过更加均质的反应环境进行聚合反应制得,其分子量和多分散系数可由撞击流速度及反应物配比调控。所得到的聚酰亚胺前驱体,其分子量分布均匀、多分散系数低,通过将高分子量的聚酰亚胺前驱体和低分子量的聚酰亚胺前驱体混合后,经高温固化制备的聚酰亚胺薄膜不仅机械性能优异,还具有与无机层表面粘附力强等特性。(The invention discloses a polyimide precursor polyamic acid solution and a preparation method of a film thereof. The polyimide precursor prepared by the method is prepared by mixing emulsion containing acid dianhydride A with an aromatic structure and solution or emulsion containing diamine B with an aromatic structure, and performing polymerization reaction in a more homogeneous reaction environment under the action of impinging stream by using an impinging stream reactor, wherein the molecular weight and the polydispersity index of the polyimide precursor can be regulated and controlled by the impinging stream speed and the reactant ratio. The obtained polyimide precursor has uniform molecular weight distribution and low polydispersity, and a polyimide film prepared by mixing the polyimide precursor with high molecular weight and the polyimide precursor with low molecular weight and curing at high temperature has the characteristics of excellent mechanical property, strong adhesion with the surface of an inorganic layer and the like.)

1. A method for preparing a polyimide precursor polyamic acid solution using an impinging stream reactor and preparing a composite polyimide film using the polyamic acid solution, the method comprising:

(1) adding diamine B into an organic solvent E for dissolving or suspending, and then uniformly dispersing or dissolving B in the solvent E through high-speed dispersion;

(2) adding acid dianhydride A into an organic solvent E for dissolving or suspending, and then uniformly dispersing A in the solvent E through high-speed dispersion;

(3) putting the two-component mixed solution prepared in the steps (1) and (2) and other additives into a premixing tank of an impinging stream reactor for premixing; then inputting the solution into a feed inlet of the impinging stream reactor through a pump, enabling the liquid flow to the central surface of the container through a guide shell at a high speed under the action of pressure, enabling the liquid flow to undergo front impact at the center for reaction, controlling the impinging stream speed, the reaction temperature and the reaction time of the impinging stream reactor, and obtaining a polyamic acid solution D with controllable molecular weight after the polymerization is finished; regulating and controlling the ratio of reactants and the impact flow rate to obtain a polyamic acid solution with lower weight average molecular weight and a polyamic acid solution with higher weight average molecular weight, and uniformly mixing the polyamic acid solution with lower weight average molecular weight and the polyamic acid solution with higher weight average molecular weight to obtain the Tandem type polyamic acid solution.

(4) And (3) uniformly mixing the polyamic acid solution with lower weight average molecular weight and the polyamic acid solution with higher weight average molecular weight obtained in the step (3), coating and curing to obtain the polyimide film S1, then carrying out Chemical Vapor Deposition (CVD) on the film to form a silicon dioxide layer on the surface of S1, then carrying out CVD on the surface of the silicon dioxide layer to form an amorphous silicon layer, then coating the slurry mixed with the polyamic acid solution on the amorphous silicon layer again, and curing to obtain the composite polyimide film.

2. The preparation method according to claim 1, wherein the acid dianhydride A is any acid dianhydride monomer which can be used for polyimide synthesis, preferably an acid dianhydride monomer containing an aromatic structure is used; more preferably one or both of 3,3',4,4' -biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA).

3. The preparation method according to claim 1, wherein the diamine B is any diamine monomer that can be used for polyimide synthesis, preferably diamine monomers containing aromatic structures; more preferably one or two of p-Phenylenediamine (PDA) and 2,2 '-bistrifluoromethyl-4, 4' -diaminobiphenyl (TFMB).

4. The method according to claim 1, wherein the other additives in the step (3) include a catalyst and/or a phosphate compound.

5. The method according to claim 1, wherein the flow rate of the impact is controlled to 200mL/s to 700mL/s in the step (3).

6. The method according to claim 1, wherein the lower part of the weight average molecular weight of the polyamic acid solution is 50865 to 54019, and the higher part of the weight average molecular weight thereof is 121690 to 140861.

7. The preparation method of claim 1, wherein the obtained polyamic acid has a uniform molecular weight distribution and a polydispersity index of 1.100-1.175.

8. The preparation method according to claim 1, wherein the reaction temperature in the step (3) is 10-80 ℃ and the reaction time is 6-50 h.

9. The method according to claim 1, wherein the thickness of the silicon dioxide layer and the amorphous silicon layer in the step (4) is within the range ofThe adhesion force between the first PI film and the silicon dioxide layer is 0.82-1.08N/cm, and the adhesion force between the second polyamic acid film and the amorphous silicon layer is 0.42-0.58N/cm.

10. Use of the polyamic acid solution and the composite Polyimide (PI) film according to claim 1 in the field of flexible display.

Technical Field

The invention relates to a polyimide precursor polyamic acid and polyimide mixed film, in particular to a preparation method for preparing a polyimide precursor by using an impinging stream reactor for flexible display.

Background

Polyimide (PI) films have the characteristics of being light and flexible, and can be applied to the field of panel display as a substitute for glass substrates. With the continuous advance of the manufacturing technology of flexible display screens, higher requirements are also put forward on PI film materials, and particularly when a composite layer of a PI layer and an inorganic layer is manufactured, PI is required to have more excellent heat resistance, dimensional stability, chemical corrosion resistance and mechanical strength, and the PI layer and the inorganic layer are required to have better adhesion.

Generally, the PI resin having a smaller molecular weight has a good wetting effect with a substrate, and the resin molecules can come into close contact with the substrate molecules by thermal brownian motion during baking under the same conditions, so that the PI resin has strong adhesion with the substrate, but the PI resin having a smaller molecular weight has weak cohesion, and thus exhibits poor corrosion resistance and insufficient mechanical properties. On the other hand, the PI resin having a large molecular weight has a strong cohesive force, thus showing strong corrosion resistance and good mechanical properties, but the PI resin having a large molecular weight has a poor wetting effect with the substrate, and the resin molecules cannot come into close contact with the substrate molecules by the hot brownian motion during the baking process under the same conditions, so that the adhesion with the substrate is weak.

In order to improve the adhesion between the PI film and the inorganic layer, a silane coupling agent is generally added to the polyamic acid or a siloxane structure is introduced to the polyamic acid monomer. Although the addition of the silane coupling agent can obviously improve the bonding force between the PI layer and the inorganic layer, the coupling agent usually contains silicon element or some aliphatic structures, so that after high-temperature curing, the PI film usually contains higher concentration of silicon element, and simultaneously, higher volatile matters are overflowed in the curing process of the polyamic acid due to the existence of the aliphatic structures. Therefore, in some applications in special fields, the use of the method is limited, such as the fabrication process of AMOLED.

Since the polyimide obtained by thermal curing has weak bonding force with the surface of many materials, a coupling agent is often required to be added to improve the bonding force of the polyimide with some materials. However, the addition of the coupling agent often causes the properties of the polyimide to change, thereby limiting the use of the coupling agent.

When the polyamic acid is synthesized by the conventional method, it is generally difficult to reduce the polydispersity index (PDI) to a very low value, for example, if the polyamic acid resin synthesized by the conventional method contains a small amount of a high molecular weight portion and a small amount of a low molecular weight portion (as shown by curve 1 in fig. 1), the middle portion is a large amount of a component having insufficient wetting effect and insufficient cohesion. Therefore, reducing the PDI of the polyamic acid resin to a lower value (as shown in curve 2 in fig. 1) is significant for improving the performance of the film, and particularly, when a high molecular weight polyamic acid slurry having a small PDI and a low molecular weight polyamic acid slurry having a small PDI are mixed, a polyamic acid resin having a Tandem type molecular weight distribution (as shown in curve 3 in fig. 1) can be obtained, and the film obtained by curing the resin slurry has both good mechanical properties and good adhesion with an inorganic layer.

Disclosure of Invention

The invention utilizes the impinging stream reactor to continuously react acid dianhydride and diamine under the action of the impinging stream to successfully prepare the polyamic acid solution with adjustable molecular weight and molecular weight distribution in a wider range. The molecular weight and the molecular weight distribution (i.e. the polydispersity PDI) of the polyamic acid solution can be regulated and controlled by the impact flow velocity and the ratio of acid dianhydride to diamine, so that the polyamic acid solutions with low PDI molecular weight and high PDI molecular weight can be synthesized respectively to be combined into the Tandem type polyamic acid solution. The PI film obtained after curing the Tandem type polyamic acid solution not only has excellent mechanical property, but also greatly improves the adhesion with an inorganic layer.

In the method of the present invention, the reaction mixture is first put into a premixing tank of the impinging stream reactor for premixing. Then, inputting the solution into a feed inlet of the impinging stream reactor through a pump, enabling the liquid flow to the central surface of the container through a guide shell at a high speed under the action of pressure, enabling the liquid flow to undergo front impact at the center for reaction, controlling the reaction temperature and the impact flow rate, enabling the impacted liquid material to flow back to the premixing tank from outlets at two sides, conveying the liquid material to the feed inlet of the impinging stream reactor through the pump for reaction, realizing continuous reaction, and enabling the reaction liquid to flow out of a discharge port after the reaction is finished for a certain reaction time to obtain the polyamic acid solution with controllable molecular weight. The invention uses the impinging stream reactor to prepare the polyimide precursor, which greatly strengthens the mixing and mass transfer processes at the microscopic molecular level, increases the contact area of reaction materials due to high-speed collision of the materials in the reactor, greatly increases the heat transfer and mass transfer rates, and is prepared by carrying out polymerization reaction in a more homogeneous reaction environment by using the impinging stream reactor under the action of the impinging stream, and the obtained polyimide precursor has uniform molecular weight distribution and low polydispersity. The invention discloses a method for preparing a polyimide precursor polyamic acid solution by using an impinging stream reactor and preparing a composite polyimide film by using the polyamic acid solution, which comprises the following steps:

(1) adding diamine B into an organic solvent E for dissolving or suspending, and then uniformly dispersing or dissolving B in the solvent E through high-speed dispersion;

(2) adding acid dianhydride A into an organic solvent E for dissolving or suspending, and then uniformly dispersing A in the solvent E through high-speed dispersion;

(3) putting the two-component mixed solution prepared in the steps (1) and (2) and other additives into a premixing tank of an impinging stream reactor for premixing; then inputting the solution into a feed inlet of the impinging stream reactor through a pump, enabling the liquid flow to the central surface of the container through a guide shell at a high speed under the action of pressure, enabling the liquid flow to undergo front impact at the center for reaction, controlling the impinging stream speed, the reaction temperature and the reaction time of the impinging stream reactor, and obtaining a polyamic acid solution D with controllable molecular weight after the polymerization is finished; regulating and controlling the ratio of reactants and the impact flow rate to obtain a polyamic acid solution with lower weight average molecular weight and a polyamic acid solution with higher weight average molecular weight, and uniformly mixing the polyamic acid solution with lower weight average molecular weight and the polyamic acid solution with higher weight average molecular weight to obtain the Tandem type polyamic acid solution.

(4) And (3) uniformly mixing the polyamic acid solution with lower weight average molecular weight and the polyamic acid solution with higher weight average molecular weight obtained in the step (3), coating and curing to obtain a polyimide film S1, then carrying out Chemical Vapor Deposition (CVD) on the film to form a silicon dioxide layer on the surface of S1, then carrying out CVD on the surface of the silicon dioxide layer to form an amorphous silicon layer, then coating the slurry mixed with the polyamic acid solution on the amorphous silicon layer again, and curing to obtain the composite polyimide film capable of being prepared into a flexible panel.

The acid dianhydride a monomer used in the present invention is any acid dianhydride monomer that can be used for polyimide synthesis, and an acid dianhydride monomer containing an aromatic structure can be preferably used. Preferred examples of the acid dianhydride monomer include: one or two of 3,3',4,4' -biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA).

The diamine B monomer used in the present invention is any diamine monomer that can be used for polyimide synthesis, and an aromatic structure-containing diamine monomer can be preferably used. Preferred examples of the diamine monomer include: one or both of p-Phenylenediamine (PDA) and 2,2 '-bistrifluoromethyl-4, 4' -diaminobiphenyl (TFMB).

The ratio of acid dianhydride to diamine in the reaction system is 0.90-1.1: 1.

The solvent used in the present invention is a polar organic solvent, and includes all organic solvents which can dissolve the polyamic acid at room temperature or under heating. Preferred examples of the organic solvent include polar aprotic solvents, N-dimethylformamide, N-dimethylacetamide, N-diethylformamide, N-methyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, N-methylcaprolactam, hexamethylphosphoric triamide, dimethyl sulfoxide; solvents such as tetrahydrofuran, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, etc.; ketone solvents such as acetone, methyl ethyl ketone, diisobutyl ketone, diacetone alcohol, and cyclohexanone; the solvent used comprises the single solvent or the mixed solvent of a plurality of solvents.

The prepared polyamic acid solution may contain an imide catalyst. The imide catalyst may be a compound having a pyridine structure or a compound having an imidazole structure. Among them, preferable examples of the pyridine-based compound include quinoline, isoquinoline, pyridine, acridine, quinoxaline, 6-t-butylquinoline, 3-hydroxypyridine, 6-quinolinecarboxylic acid, 3, 4-dimethylpyridine. Among them, preferable examples of the imidazole compounds include 2-phenylimidazole, 1-methylimidazole, 1, 2-dimethylimidazole, 4-ethyl-2-methylimidazole, 2-ethyl-4-methylimidazole, 2-methylimidazole and 1-methyl-4-ethylimidazole. The imide catalysts mentioned above may be used alone or in combination of two or more. The addition amount of the imide catalyst accounts for 0.01-100% of the total amount of all dianhydride monomers and diamine monomers, wherein the addition amount is preferably 0.1-10%.

In order to prevent the polyamic acid from gelling, the prepared polyamic acid solution may contain a phosphate ester compound, such as triphenyl phosphite or triphenyl phosphate, wherein the amount of the phosphate ester compound added is 0.01 to 5% of the total solid amount.

According to the preparation method of the polyamic acid solution, the part range with lower weight average molecular weight in the polyamic acid solution is 50865-54019, the part range with higher weight average molecular weight is 121690-140861, and the mechanical property and the adhesive force of the film prepared from the polyamic acid in the range have practical use value for production; in the method for synthesizing a polyamic acid solution according to the present invention, it is necessary to dissolve or disperse an acid dianhydride or diamine monomer in a solvent to form a solution or suspension dispersed at high speed. In order to control the dispersion degree of the suspension, the rotation speed of high-speed dispersion is preferably within the range of 3000-10000 rpm/min, the particle size of the obtained suspension is 50-300 nm, then the solution or the suspension after high-speed dispersion is subjected to impinging stream reaction, the reaction temperature of the step is between 10 ℃ and 80 ℃, more preferably between 25 ℃ and 60 ℃, the impinging flow rate in the step (3) is controlled within the range of 200mL/s-700mL/s, and the reaction time is 6-50 hours.

According to the preparation method disclosed by the invention, the obtained polyamic acid has uniform molecular weight distribution, and the polydispersity coefficient is between 1.100 and 1.175; the viscosity of the finally obtained polyamic acid solution is between 1 and 7 Pa.s, more preferably between 3 and 6 Pa.s, the solid content is between 8 and 45wt percent, more preferably between 10 and 20wt percent, and the polyamic acid solution with the solid content and the viscosity range can be conveniently coated with a film and has excellent coating performance, so that the polyimide film with the film thickness within the range of 5 to 20 mu m can be easily prepared.

The preparation method also relates to a curing process of the slurry, the curing temperature in the curing process is within the range of 80-600 ℃, the generally preferred curing temperature is 120-500 ℃, and the curing procedure is generally divided into at least two stages, wherein the first stage is heating to 180-280 ℃, then heat preservation is carried out for 10-60 min, and the second stage is heating to 400-500 ℃, and the temperature is kept for 10-60 min.

The thickness of the polyimide composite film, the silicon dioxide layer and the amorphous silicon layer prepared by the invention isThe adhesion force between the first PI film and the silicon dioxide layer is 0.82-1.08N/cm, and the adhesion force between the second polyamic acid film and the amorphous silicon layer is 0.42-0.58N/cm.

The polyimide film prepared by the method has excellent mechanical properties, and the polyimide film with tensile strength of over 336Mpa, tensile modulus of over 7.09Gpa and elongation at break of over 14.26% can be easily prepared. The polyamic acid solution disclosed by the invention can be applied to the fields of flexible circuit boards, flexible AMOLED substrates, solar panels and the like, and is particularly suitable for the flexible AMOLED substrates when a proper monomer structure is selected. The polyimide film obtained by curing the polyamic acid solution obtained by the invention has excellent mechanical properties, excellent dimensional stability, good adhesion with a glass substrate, excellent bending resistance and excellent thermal stability, and is very suitable for AMOLED substrate materials.

The polyamic acid solution obtained by the process described in this patent has a polydispersity index and a molecular weightIn a very wide rangeThe range of the polyimide film is adjustable, and simultaneously, the polyimide film obtained by curing the polyamic acid has excellent comprehensive performance. In particular, the adhesion between the cured polyimide film and the inorganic layer is significantly improved.

Drawings

FIG. 1 is a schematic illustration of the molecular weight distribution of a polyamic acid slurry;

wherein, curve 1 is a schematic diagram of a conventional method for synthesizing a polyamic acid resin containing a small amount of a high molecular weight portion and a small amount of a low molecular weight portion,

curve 2 is a graph showing the molecular weight distribution of polyamic acid having a small PDI,

curve 3 is a schematic view of the Tandem type molecular weight distribution after mixing the high molecular weight polyamic acid slurry having a small PDI and the low molecular weight polyamic acid slurry having a small PDI;

FIG. 2 is a flow diagram of the structure of an impinging stream reactor of the present invention; wherein: 1-a premixing tank, 2-a circulating pump, 3-a feed inlet, 4-a guide shell, 5-a material impact area, 6-a circulating outlet and 7-a discharge hole.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The structural flow of the impinging stream reactor of the invention is as followsFIG. 2As shown. First, the reaction mixture liquid dispersed is put into the premix tank 1 of the impinging stream reactor, and premixed. Then, the mixed liquid is input into the feed inlets 3 at two sides of the impinging stream reactor through the circulating pump 2, the mixed liquid flows to the central surface of the vessel through the guide shell 4 at a high speed under the action of pressure, and the front impinging reaction is carried out at the central part 5. The liquid materials after the impact flow back to the premixing tank from the circulating outlets 6 at the two sides, and then are conveyed to the impact flow reactor through the circulating pump for reaction, so that the continuous reaction is realized. After the reaction, the reaction solution was discharged from the discharge port 7.

The following are abbreviations for the compounds used in examples and comparative examples.

BPDA: 3,3',4,4' -biphenyltetracarboxylic dianhydride

And (3) PMDA: pyromellitic dianhydride

TFMB: 2,2 '-bistrifluoromethyl-4, 4' -diaminobiphenyl

PDA: p-phenylenediamine

NMP: n-methyl-2-pyrrolidone

Example 1

Step 1: 320.23g (1.0mol) of TFMB and 1814.64g of NMP are stirred and dissolved at 30 ℃, and then the mixture is rapidly added into a high-speed disperser to be dispersed, and the dispersion liquid or solution of TFMB is obtained after 2 hours of dispersion; 270.68g (0.92mol) of BPDA and 1533.85g of NMP were dissolved with stirring at 30 ℃ and the mixture was rapidly charged into a high-speed disperser and dispersed for 2 hours to obtain a dispersion or solution of BPDA. The TFMB dispersion or solution, 2.95g of pyridine and BPDA dispersion or solution were then charged into the premix tank of the impinging stream reactor and mixed. The mixed solution is input into a feed inlet of an impinging stream reactor through a pump, liquid flow flows to the central surface of a container through a guide shell at high speed under the action of pressure, front impact is generated at the center for reaction, the reaction temperature is controlled to be 40 ℃, the pressure in the system is 0.3MPa, the impinging stream speed is maintained at 600mL/s, the impinged liquid material flows back to a premixing tank from outlets at two sides, the liquid material is conveyed to the feed inlet of the impinging stream reactor through the pump for reaction, the continuous reaction is realized, the reaction time is 24h, and after the reaction is stopped, the slurry D1 is obtained through discharging.

Slurry D2 was obtained by adjusting the amount of pyridine used in step 1 of example 1 to 0 g.

Slurry D3 was obtained by adjusting the amount of pyridine used in step 1 of example 1 to 3.06g, the amount of BPDA to 291.28g (0.99mol) and the amount of the BPDA dispersion or solution to 1941.87 g.

100g of slurry D1 and 500g of slurry D3 were mixed uniformly to obtain slurry L1.

Example 2

Slurry L2 was obtained by uniformly mixing 300g of slurry D1 and 300g of slurry D3.

Example 3

500g of slurry D1 and 100g of slurry D3 were mixed uniformly to obtain slurry L3.

Example 4

Step 1: 108.14g (1.0mol) of PDA and 612.79g of NMP are stirred and dissolved at the temperature of 30 ℃, then the mixture is rapidly added into a high-speed dispersion machine for dispersion, and dispersion liquid or solution of PDA is obtained after 2 hours of dispersion; 270.68g (0.92mol) of BPDA and 1533.85g of NMP were dissolved with stirring at 30 ℃ and the mixture was rapidly charged into a high-speed disperser and dispersed for 2 hours to obtain a dispersion or solution of BPDA. The PDA dispersion or solution, 1.89g of pyridine and BPDA dispersion or solution were then charged into the premix tank of the impinging stream reactor and mixed. The mixed solution is input into a feed inlet of an impinging stream reactor through a pump, liquid flow flows to the central surface of a container through a guide shell at high speed under the action of pressure, front impact is generated at the center for reaction, the reaction temperature is controlled to be 40 ℃, the pressure in the system is 0.3MPa, the impinging stream speed is maintained at 600mL/s, the impinged liquid material flows back to a premixing tank from outlets at two sides, the liquid material is conveyed to the feed inlet of the impinging stream reactor through the pump for reaction, the continuous reaction is realized, the reaction time is 24h, and after the reaction is stopped, the slurry D4 is obtained through discharging.

Slurry D5 was obtained by adjusting the amount of pyridine used in step 1 of example 4 to 2.00g, the amount of BPDA to 291.28g (0.99mol) and the amount of the BPDA dispersion or solution to 1941.87 g.

100g of slurry D4 and 500g of slurry D5 were mixed uniformly to obtain slurry L4.

Example 5

Slurry L5 was obtained by uniformly mixing 300g of slurry D4 and 300g of slurry D5.

Example 6

500g of slurry D4 and 100g of slurry D5 were mixed uniformly to obtain slurry L6.

Example 7

Step 1: 320.23g (1.0mol) of TFMB and 1814.64g of NMP are stirred and dissolved at 30 ℃, and then the mixture is rapidly added into a high-speed disperser to be dispersed, and the dispersion liquid or solution of TFMB is obtained after 2 hours of dispersion; 200.67g (0.92mol) of PMDA and 1137.13g of NMP were dissolved by stirring at 30 ℃ and then the mixture was rapidly fed into a high-speed disperser to be dispersed for 2 hours to obtain a dispersion or solution of PMDA. The TFMB dispersion or solution, 2.60g of pyridine and PMDA dispersion or solution were then charged into the premix tank of the impinging stream reactor and mixed. The mixed solution is input into a feed inlet of an impinging stream reactor through a pump, liquid flow flows to the central surface of a container through a guide shell at high speed under the action of pressure, front impact is generated at the center for reaction, the reaction temperature is controlled to be 40 ℃, the pressure in the system is 0.3MPa, the impinging stream speed is maintained at 600mL/s, the impinged liquid material flows back to a premixing tank from outlets at two sides, the liquid material is conveyed to the feed inlet of the impinging stream reactor through the pump for reaction, the continuous reaction is realized, the reaction time is 24h, and after the reaction is stopped, the slurry D6 is obtained through discharging.

Slurry D7 was obtained by adjusting the amount of pyridine used in step 1 of example 7 to 2.68g, the amount of PMDA to 215.94g (0.99mol) and the amount of PMDA dispersion or solution to 1439.59 g.

100g of slurry D6 and 500g of slurry D7 were mixed uniformly to obtain slurry L7.

Example 8

Slurry L8 was obtained by uniformly mixing 300g of slurry D6 and 300g of slurry D7.

Example 9

500g of slurry D6 and 100g of slurry D7 were mixed uniformly to obtain slurry L9.

Example 10

Step 1: 108.14g (1.0mol) of PDA and 612.79g of NMP are stirred and dissolved at the temperature of 30 ℃, then the mixture is rapidly added into a high-speed dispersion machine for dispersion, and dispersion liquid or solution of PDA is obtained after 2 hours of dispersion; 200.67g (0.92mol) of PMDA and 1137.13g of NMP were dissolved by stirring at 30 ℃ and then the mixture was rapidly fed into a high-speed disperser to be dispersed for 2 hours to obtain a dispersion or solution of PMDA. The PDA dispersion or solution, 1.54g of pyridine and the PMDA dispersion or solution were then charged into the premix tank of the impinging stream reactor and mixed. The mixed solution is input into a feed inlet of an impinging stream reactor through a pump, liquid flow flows to the central surface of a container through a guide shell at high speed under the action of pressure, front impact is generated at the center for reaction, the reaction temperature is controlled to be 40 ℃, the pressure in the system is 0.3MPa, the impinging stream speed is maintained at 600mL/s, the impinged liquid material flows back to a premixing tank from outlets at two sides, the liquid material is conveyed to the feed inlet of the impinging stream reactor through the pump for reaction, the continuous reaction is realized, the reaction time is 24h, and after the reaction is stopped, the slurry D8 is obtained through discharging.

Slurry D9 was obtained by adjusting the amount of pyridine used in step 1 of example 10 to 1.62g, the amount of PMDA to 215.94g (0.99mol), and the amount of PMDA dispersion or solution to 1439.59 g.

100g of slurry D8 and 500g of slurry D9 were mixed uniformly to obtain slurry L10.

Example 11

Slurry L11 was obtained by uniformly mixing 300g of slurry D8 and 300g of slurry D9.

Example 12

500g of slurry D8 and 100g of slurry D9 were mixed uniformly to obtain slurry L12.

Example 13

Step 1: 320.23g (1.0mol) of TFMB and 1814.64g of NMP are stirred and dissolved at 30 ℃, and then the mixture is rapidly added into a high-speed disperser to be dispersed, and the dispersion liquid or solution of TFMB is obtained after 2 hours of dispersion; 270.68g (0.92mol) of BPDA and 1533.85g of NMP were dissolved with stirring at 30 ℃ and the mixture was rapidly charged into a high-speed disperser and dispersed for 2 hours to obtain a dispersion or solution of BPDA. The TFMB dispersion or solution, 2.95g of pyridine and BPDA dispersion or solution were then charged into the premix tank of the impinging stream reactor and mixed. The mixed solution is input into a feed inlet of an impinging stream reactor through a pump, liquid flow flows to the central surface of a container through a guide shell at high speed under the action of pressure, front impact is generated at the center for reaction, the reaction temperature is controlled to be 40 ℃, the pressure in the system is 0.3MPa, the impinging stream speed is maintained at 450mL/s, the impinged liquid material flows back to a premixing tank from outlets at two sides, the liquid material is conveyed to the feed inlet of the impinging stream reactor through the pump for reaction, the continuous reaction is realized, the reaction time is 24h, and after the reaction is stopped, the slurry D10 is obtained through discharging.

Slurry D11 was obtained by adjusting the amount of pyridine used in step 1 of example 13 to 3.06g, the amount of BPDA to 291.28g (0.99mol) and the amount of the BPDA dispersion or solution to 1941.87 g.

100g of slurry D10 and 500g of slurry D11 were mixed uniformly to obtain slurry L13.

Example 14

Step 1: 320.23g (1.0mol) of TFMB and 1814.64g of NMP are stirred and dissolved at 30 ℃, and then the mixture is rapidly added into a high-speed disperser for dispersion, and a TMFB dispersion liquid or solution is obtained after 2 hours of dispersion; 270.68g (0.92mol) of BPDA and 1533.85g of NMP were dissolved with stirring at 30 ℃ and the mixture was rapidly charged into a high-speed disperser and dispersed for 2 hours to obtain a dispersion or solution of BPDA. The TFMB dispersion or solution, 2.95g of pyridine and BPDA dispersion or solution were then charged into the premix tank of the impinging stream reactor and mixed. The mixed solution is input into a feed inlet of an impinging stream reactor through a pump, liquid flow flows to the central surface of a container through a guide shell at high speed under the action of pressure, front impact is generated at the center for reaction, the reaction temperature is controlled to be 40 ℃, the pressure in the system is 0.3MPa, the impinging stream speed is maintained at 300mL/s, the impinged liquid material flows back to a premixing tank from outlets at two sides, the liquid material is conveyed to the feed inlet of the impinging stream reactor through the pump for reaction, the continuous reaction is realized, the reaction time is 24h, and after the reaction is stopped, the slurry D12 is obtained through discharging.

Slurry D13 was obtained by adjusting the amount of pyridine used in step 1 of example 14 to 3.06g, the amount of BPDA to 291.28g (0.99mol) and the amount of the BPDA dispersion or solution to 1941.87 g.

100g of slurry D12 and 500g of slurry D13 were mixed uniformly to obtain slurry L14.

Comparative example 1

320.23g (1.0mol) of TFMB, 2.95g of pyridine and 1814.64g of NMP were added to a reaction vessel under a dry nitrogen stream, and after mechanical stirring for 2 hours, 270.68g (0.92mol) of BPDA and 1533.85g of NMP were added thereto, and the reaction was stopped at 40 ℃ for 24 hours to obtain a slurry L15.

Comparative example 2

320.23g (1.0mol) of TFMB, 3.00g of pyridine and 1814.64g of NMP were added to a reaction vessel under a dry nitrogen stream, and after mechanical stirring for 2 hours, 279.51g (0.95mol) of BPDA and 1583.89g of NMP were added thereto, and the reaction was stopped at 40 ℃ for 24 hours to obtain a slurry L16.

Comparative example 3

320.23g (1.0mol) of TFMB, 3.06g of pyridine and 1814.64g of NMP were added to a reaction vessel under a dry nitrogen stream, and after mechanical stirring for 2 hours, 291.28g (0.99mol) of BPDA and 1650.59g of NMP were added thereto, and the reaction was stopped at 40 ℃ for 24 hours to obtain a slurry L17.

Comparative example 4

100g of slurry L15 and 500g of slurry L17 were mixed uniformly to obtain slurry L18.

Comparative example 5

108.14g (1.0mol) of PDA, 1.89g of pyridine and 612.79g of NMP were put into a reaction vessel under a dry nitrogen stream, mechanically stirred for 2 hours, and then 270.68g (0.92mol) of BPDA and 1533.85g of NMP were added thereto, and reacted at 40 ℃ for 24 hours, and the reaction was stopped to obtain a slurry D14.

108.14g (1.0mol) of PDA, 2.00g of pyridine and 612.79g of NMP were put into a reaction vessel under a dry nitrogen stream, and after mechanical stirring for 2 hours, 291.28g (0.99mol) of BPDA and 1650.59g of NMP were added thereto, and reacted at 40 ℃ for 24 hours, and the reaction was stopped to obtain a slurry D15.

100g of slurry D14 and 500g of slurry D15 were mixed uniformly to obtain slurry L19.

Comparative example 6

320.23g (1.0mol) of TFMB, 2.60g of pyridine and 1814.64g of NMP were added to a reaction vessel under a dry nitrogen stream, and after mechanical stirring for 2 hours, 200.67g (0.92mol) of PMDA and 1137.13g of NMP were added thereto, and the reaction was stopped at 40 ℃ for 24 hours to obtain a slurry D16.

320.23g (1.0mol) of TFMB, 2.68g of pyridine and 1814.64g of NMP were added to a reaction vessel under a dry nitrogen stream, and after mechanical stirring for 2 hours, 215.94g (0.99mol) of PMDA and 1223.65g of NMP were added thereto, and the reaction was stopped at 40 ℃ for 24 hours to obtain a slurry D17.

100g of slurry D16 and 500g of slurry D17 were mixed uniformly to obtain slurry L20.

Comparative example 7

108.14g (1.0mol) of PDA, 1.54g of pyridine and 612.79g of NMP were put into a reaction vessel under a dry nitrogen stream, mechanically stirred for 2 hours, and then 200.67g (0.92mol) of PMDA and 1137.13g of NMP were added thereto, and reacted at 40 ℃ for 24 hours, and the reaction was stopped to obtain a slurry D18.

108.14g (1.0mol) of PDA, 1.62g of pyridine and 612.79g of NMP were put into a reaction vessel under a dry nitrogen stream, and mechanically stirred for 2 hours, then 215.94g (0.99mol) of PMDA and 1223.65g of NMP were added thereto, and reacted at 40 ℃ for 24 hours, and the reaction was stopped to obtain a slurry D19.

100g of slurry D18 and 500g of slurry D19 were mixed uniformly to obtain slurry L21.

Preparation of polyimide film

Respectively and uniformly blade-coating the polyamide acid slurry provided by the embodiment 1-14 and the comparative example 1-7 on a glass/amorphous silicon substrate through a scraper to form a film, heating the wet film obtained by blade-coating from room temperature to 200 ℃ at a speed of 10 ℃/min in an oven, then preserving heat at 200 ℃ for 50min, heating to 400 ℃ at a speed of 10 ℃/min, then preserving heat at 400 ℃ for 50min to obtain a cured polyimide film, and then carrying out various evaluations.

Test example 1

The present test example provides performance evaluations of the polyimide films provided in examples 1 to 14 and comparative examples 1 to 7.

(1) Solid content test

The sample is uniformly coated in a glass container, and the mass m of the sample is weighed₁. And (3) heating the coated sample in an oven, keeping the temperature at 100 ℃ for 30min, heating to 350 ℃ at the speed of 5 ℃/min, and keeping the temperature at 350 ℃ for 30 min. Weighing the sample after the sample is cooled₂. The solid content of the sample was calculated according to the following formula:

solid content ═ m₂/m₁)×100％

(2) Mechanical Property test

The test specimen width was 10mm, the jig interval was 50mm, the test speed was 50mm/min, and the number of test specimens was 10 groups, as measured by a universal material testing machine (Instron 3360).

(3) Adhesion test to inorganic layer

The test environment is 25 ℃, the humidity is 50% +/-5%, the polyimide slurry is cured at high temperature on a glass/amorphous silicon substrate and is placed for 24h, the sample size is 25mm wide and 200mm long, the polyimide film is peeled off at a speed of 100mm/min by a tensile machine (Shimadzu AGS-X, the upper limit of the sensor is 200N) at 180 degrees in the sample direction, and the obtained data is the adhesion force of the polyimide film and the inorganic layer.

(4) Gel Permeation Chromatography (GPC) detection

Measured by using a gel chromatograph of Shimadzu GPC-20A.

Table 1 is a statistical table of the solid content, number average molecular weight, weight average molecular weight, polydispersity index performance data of different slurries obtained in the inventive examples and comparative examples.

TABLE 1 Properties of the slurries

Slurry material	Solid content	Number average molecular weight	Weight average molecular weight	Polydispersity index
					D1	15％	46806	52469	1.121
D2	15％	45329	50996	1.125
					D3	15％	122512	135866	1.109
D4	15％	47900	53648	1.120
					D5	15％	124909	138524	1.109
D6	15％	47238	52954	1.121
					D7	15％	124156	137565	1.108
D8	15％	48145	54019	1.122
					D9	15％	127016	140861	1.109
D10	15％	44709	51684	1.156
					D11	15％	111858	128413	1.148
D12	15％	43289	50865	1.175
					D13	15％	104187	121690	1.168
D14	15％	32646	46521	1.425
					D15	15％	87243	122315	1.402
D16	15％	31906	45689	1.432
					D17	15％	86507	121196	1.401
D18	15％	32912	46998	1.428
					D19	15％	89589	125693	1.403
L15	15％	32231	45962	1.426
					L16	15％	53305	75426	1.415
L17	15％	86044	120633	1.402

As is evident from the results in table 1, the polymers produced by the impinging stream reactor have a relatively small PDI, which provides a convenient method for the synthesis of Tandem-type polyamic acid solutions. Further, the larger the impinging stream velocity, the smaller the PDI value of the resulting polymer, and the larger the molecular weight.

Table 2 is a statistical table of performance data of polyimide hybrid films prepared using different pastes obtained in the inventive example and the comparative example.

TABLE 2 Properties of polyimide hybrid films

As can be seen from table 2, the adhesion force with the inorganic layer and the mechanical properties of the film obtained from the polyamic acid slurry synthesized by the conventional method through curing cannot be compatible, while the adhesion force with the inorganic layer and the mechanical properties of the film obtained from the Tandem-type polyamic acid slurry prepared by the impinging stream reactor of the present invention are excellent.

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.