CN115636965B

CN115636965B - High-transmittance polyisophthaloyl metaphenylene diamine film and preparation method thereof

Info

Publication number: CN115636965B
Application number: CN202211670875.3A
Authority: CN
Inventors: 关振虹; 李丹; 王梅阁; 杨东平; 宋西全
Original assignee: Yantai Taihe New Material Polymer New Material Research Institute Co ltd
Current assignee: Yantai Taihe New Material Polymer New Material Research Institute Co ltd
Priority date: 2022-12-26
Filing date: 2022-12-26
Publication date: 2023-03-21
Anticipated expiration: 2042-12-26
Also published as: CN115636965A

Abstract

The invention discloses a high-transmittance polyisophthaloyl metaphenylene diamine film and a preparation method thereof, belonging to the technical field of optical films of flexible electronic devices.A metaphenylene diamine and aromatic diamine are dissolved in an organic solvent according to a preset proportion, isophthaloyl dichloride is added for polycondensation reaction, and a neutralizer is added after the reaction is finished to obtain a polymer solution of the polyisophthaloyl metaphenylene diamine with high molecular weight; the poly (m-phenylene isophthalamide) with low molecular weight is added into the polymer solution to be blended into slurry, and after tape-casting forming, drying, stretching, heat setting treatment and annealing and rolling, the obtained poly (m-phenylene isophthalamide) film has excellent transparency and hydrolysis resistance compared with the traditional polyimide film, can be used without reducing Charge Transfer Complex (CTC) effect, has excellent visible light transmittance and can be directly used, and the preparation process is simple, the production cost is low, and the application in the field of flexible electronic devices can be met.

Description

High-transmittance polyisophthaloyl metaphenylene diamine film and preparation method thereof

Technical Field

The invention belongs to the technical field of optical films of flexible electronic devices, and relates to a high-transmittance polyisophthaloyl metaphenylene diamine film and a preparation method thereof.

Background

With the development of photoelectric devices, the traditional transparent glass substrate cannot meet the requirements of flexible devices, and colorless transparent polymers have the advantages of transparency, light weight, impact resistance and the like, so that the colorless transparent polymers are increasingly emphasized in the fields of patterned display equipment, liquid crystal orientation layers, optical films, organic photovoltaic solar panels, flexible printed circuit boards, touch screens and the like. In the fabrication of photoelectric devices, since high-temperature treatment is required during deposition of an electrode film and annealing, a polymer as a substrate must have good heat resistance. In addition to transparency and heat resistance, polymers as flexible substrates are also required to have good dimensional stability, flexibility, excellent solvent resistance, and a simple film forming process.

Since the polymer film of the transparent flexible substrate of the flexible device in the market is a modified polyimide film, the polyimide has high technical threshold due to the production process, the material and equipment cost is high, the production efficiency is low, the polyimide has deep color, so that the polyimide must be modified, and the polyimide can be used after the Charge Transfer Complex (CTC) effect is reduced, which undoubtedly increases the production cost and the technical difficulty and cannot be produced in batch, therefore, a material and a preparation method are urgently needed to solve the technical problems existing in the polymer film of the transparent flexible substrate of the existing flexible device.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the high-transmittance polyisophthaloyl metaphenylene diamine film and the preparation method thereof, the prepared high-transmittance polyisophthaloyl metaphenylene diamine film has excellent insulativity and high temperature resistance, the preparation process is simple, the production cost is low, the film can be used after the Charge Transfer Complex (CTC) effect is not reduced, the film has excellent transparency and can be directly used, and the application in the field of flexible electronic devices can be met.

The invention is realized by the following technical scheme:

a method for preparing a high-transmittance polyisophthaloyl metaphenylene diamine film comprises,

s1, dissolving m-phenylenediamine and aromatic diamine in an organic solvent according to a preset proportion, then adding isophthaloyl dichloride in batches for polycondensation reaction, and adding a neutralizer after the reaction is finished for treatment to obtain a polymer solution of the polyisophthaloyl metaphenylene diamine with high molecular weight;

s2, adding low-molecular-weight polyisophthaloyl metaphenylene diamine into the high-molecular-weight polyisophthaloyl metaphenylene diamine polymer solution to prepare slurry, and obtaining the high-transmittance polyisophthaloyl metaphenylene diamine film after tape-casting forming, drying, stretching, heat setting treatment, annealing and rolling.

Preferably, the molar ratio of the m-phenylenediamine to the aromatic diamine is (50 to 97): (3 to 50), and the molar ratio of the total mole of the m-phenylenediamine and the aromatic diamine to the isophthaloyl dichloride (1; the addition amount of the low-molecular-weight polyisophthaloyl metaphenylene diamine in the slurry accounts for 3-9 wt% of the total amount; the pH of the polymer solution of the high-molecular-weight polyisophthaloyl metaphenylene diamine after neutralization by adding the neutralizing agent is 7 to 8.5.

Preferably, the specific process for preparing the polymer solution of the polyisophthaloyl metaphenylene diamine with high molecular weight in S1 comprises the following steps:

dissolving m-phenylenediamine and aromatic diamine in an organic solvent according to a preset proportion, adding isophthaloyl dichloride in three batches for polycondensation, adding a neutralizer for neutralization after the reaction is finished, and obtaining a polymer solution of polyisophthaloyl metaphenylene diamine with high molecular weight, wherein the system viscosity is 30-60 Pa.s;

wherein the reaction temperature of the added first batch of isophthaloyl dichloride is controlled to be 25-35 ℃, the stirring speed is 500-800 r/min, and the viscosity of the system solution after the reaction at the stage is finished is 0.1-0.3 Pa.s; after the second batch of isophthaloyl dichloride is added, the reaction temperature is controlled to be 35-45 ℃, the stirring speed is 400-600 r/min, and the viscosity of the system solution after the reaction at the stage is finished is 6-20 Pa.s; after the third batch of isophthaloyl dichloride is added, the reaction temperature is controlled to be 45-65 ℃, the stirring speed is 200-300 r/min, and the viscosity of the system solution after the reaction at the stage is finished is 50-80 Pa.s.

Preferably, the specific process for preparing the polyisophthaloyl metaphenylene diamine film in S2 comprises the following steps:

adding polyisophthaloyl metaphenylene diamine into a polymer solution of the polyisophthaloyl metaphenylene diamine with high molecular weight to prepare slurry, casting the slurry on a steel belt to form a film, stripping the formed film from the steel belt after high-temperature treatment, drying, performing double-drawing shaping process and heat shaping treatment, and finally annealing and rolling to obtain the polyisophthaloyl metaphenylene diamine film;

wherein the roughness Ra of the steel strip is less than 0.2 mu m;

the high-temperature treatment temperature is 120-150 ℃, and the high-temperature treatment time is 1-20min;

the drying temperature is 130-200 ℃, the drying time is 3-10min, and the content of the organic solvent in the dried film is 0.5-1.5 wt%;

in the double-drawing shaping process, the film is subjected to bidirectional drawing by regulating and controlling the temperature and the drawing ratio; the temperature is regulated and controlled by adopting subareas, and 8 areas are shared, wherein the 1 st area is a temperature rise transition area, and the temperature is controlled to be 100-120 ℃; the 2 nd area is a temperature stabilizing area, and the temperature is controlled to be 120-135 ℃; the 3 rd zone is a stretching first zone, and the temperature is controlled to be 150-180 ℃; the 4 th area is a stretching second area, and the temperature is controlled to be 180-200 ℃; the 5 th area is a stretching three area, and the temperature is controlled to be 250-300 ℃; the 6 th area is a shaping area, and the temperature is controlled to be 240-270 ℃; the 7 th area is a cooling transition area, the temperature is controlled to be 150-180 ℃, and the 8 th area is a cooling area, the temperature is controlled to be 100-130 ℃;

the stretch ratio of the first stretch zone in the 3 rd zone is 1.05 to 1.5, the stretch ratio of the second stretch zone in the 4 th zone is 1.5 to 1.8, and the stretch ratio of the third stretch zone in the 5 th zone is 1.8 to 3.0.

Preferably, the aromatic diamine includes one or a mixture of two or more of 4- (4 '-aminophenoxy) -3, 5-bis (trifluoromethane) aniline, 1, 3-bis (4-aminophenoxy) benzene, 9-bis (4-aminophenyl) fluorene, 4' - (phenylmethylene) bis (2-isopropylaniline), and 2- (4-aminophenyl) -5-aminobenzoxazole.

Preferably, the neutralizing agent is one of ammonia, calcium hydroxide and sodium hydroxide.

Preferably, the weight average molecular weight of the low-molecular-weight polyisophthaloyl metaphenylene diamine is 8000-30000, and the weight average molecular weight of the high-molecular-weight polyisophthaloyl metaphenylene diamine is 200000-300000.

Preferably, the organic solvent includes one of N, N-dimethylacetamide, N-dimethylformamide, N-methylpyrrolidone, and dimethylsulfoxide.

The high-transmittance polyisophthaloyl metaphenylene diamine film is prepared by the preparation method, and the transmittance of the polyisophthaloyl metaphenylene diamine film reaches 91-95%.

Preferably, the molecular orientation degree of the polyisophthaloyl metaphenylene diamine film is 40-60%, the transverse and longitudinal tensile strength of the polyisophthaloyl metaphenylene diamine film is greater than 110MPa, and the transverse and longitudinal elongation of the polyisophthaloyl metaphenylene diamine film is greater than 10%; the haze value of the polyisophthaloyl metaphenylene diamine film is less than 0.8%, and the yellowness index of the polyisophthaloyl metaphenylene diamine film is less than 1.3; the content of the solvent in the polyisophthaloyl metaphenylene diamine film is less than 200ppm; the thickness of the polyisophthaloyl metaphenylene diamine film is 8-180 mu m.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention discloses a preparation method of a high-transmittance polyisophthaloyl metaphenylene diamine film, which takes IPC, MPD and aromatic diamine compounds as monomers, and adopts a solution polymerization method to prepare a polymer solution of high-molecular-weight polyisophthaloyl metaphenylene diamine in an organic solvent, and introduces a strong electronegativity or asymmetric rigid group into the molecular structure of the polyisophthaloyl metaphenylene diamine, so that the accumulation of molecular chains of the polyisophthaloyl metaphenylene diamine can be reduced to a certain extent, the free volume between the chains is increased, and the charge transfer effect between the molecules and in the molecules is reduced, thereby improving the transparency of the film; the high-transmittance polyisophthaloyl metaphenylene diamine film prepared by the invention has excellent insulativity, high temperature resistance and mechanical properties, has excellent transparency and hydrolysis resistance compared with the traditional polyimide film prepared into a film, is used without reducing Charge Transfer Complex (CTC) effect, has excellent visible light transmittance, can be directly used, and can meet the application in the field of flexible electronic devices.

According to the invention, through the double-drawing shaping process, the temperature and the drawing ratio are accurately controlled through zone temperature control and distribution of the drawing ratio, the degree of molecular crystallinity and the degree of orientation in the film reach a balanced state, and the mechanical property of the film is fully improved on the premise of ensuring excellent transparency of the film.

According to the preparation method, a certain amount of low molecular weight poly (m-phenylene isophthalamide) is added into a polymer solution of high molecular weight poly (m-phenylene isophthalamide) in the slurry preparation process, so that the low molecular weight chain segment has high freedom of motion in the stretching process, is easy to crystallize and orient, and further promotes the rapid crystallization and orientation of a film in the stretching process.

Detailed Description

Technical solutions in embodiments of the present invention are clearly and completely described in order to enable those skilled in the art to better understand the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, shall fall within the protection scope of the present invention.

The polyisophthaloyl metaphenylene diamine has excellent insulating property and high temperature resistance, and the high-transmittance polyisophthaloyl metaphenylene diamine film prepared by the method has excellent insulating property, high temperature resistance and transparency by performing molecular design on the polyisophthaloyl metaphenylene diamine and researching a film preparation process, and can meet the application in the field of flexible electronic devices.

A preparation method of a high-transmittance polyisophthaloyl metaphenylene diamine film comprises the following specific steps:

by adopting a solution polymerization method and molecular structural design, an asymmetric or rigid non-planar structure is introduced into a polyisophthaloyl metaphenylene diamine structure, the order and symmetry of the polyisophthaloyl metaphenylene diamine molecular structure are reduced, a polymer solution of the polyisophthaloyl metaphenylene diamine with colorless and high molecular weight is obtained, then low molecular weight polyisophthaloyl metaphenylene diamine is added into the solution to prepare a proper slurry, and then a polyisophthaloyl metaphenylene diamine film with the transmittance of 91% -95% is obtained after tape casting, drying, stretching, heat setting, annealing and rolling.

The method comprises the following steps: slurry preparation

After m-phenylenediamine (MPD) and aromatic diamine are fully dissolved in an organic solvent according to a certain proportion, maintaining the MPD and aromatic diamine solution at 10 ℃, then adding isophthaloyl dichloride (IPC) in three batches, controlling the stirring speed of a reaction kettle and the reaction temperature of a system during the polycondensation reaction process of adding IPC in each batch, ensuring the strict control of the viscosity of the system after adding IPC in each batch, adding a neutralizer after the reaction is finished, and controlling the pH of the neutralized system to be 7.0-8.5 to obtain a colorless transparent polymer solution of the high-molecular-weight poly-m-phenylene isophthalamide, wherein the viscosity of the system is 30-60 Pa.s, and the solid content of the high-molecular-weight poly-m-phenylene isophthalamide (H-PMIA) is 10-18%. Selecting poly (m-phenylene isophthalamide) (L-PMIA) with lower molecular weight to mix with polymer solution of poly (m-phenylene isophthalamide) with high molecular weight to prepare slurry, wherein the weight ratio of L-PMIA in the slurry is 3wt% -9 wt%.

Step two: preparation of polyisophthaloyl metaphenylene diamine film

And (2) casting the slurry obtained in the step one on a steel belt to form a film, treating at a high temperature, peeling the formed film from the steel belt, then putting the film into a drying oven, controlling the drying time to enable the dried film to contain a certain organic solvent, then putting the film into a double-drawing forming process, regulating and controlling the temperature and the drawing ratio, then forming, and finally annealing and rolling to obtain the polyisophthaloyl metaphenylene diamine transparent film.

Further, the aromatic diamine includes one or more of 4- (4 '-aminophenoxy) -3, 5-bis (trifluoromethane) aniline (PBTFA), 1, 3-bis (4-aminophenoxy) benzene (1, 3, 4-APB), 9-bis (4-aminophenyl) Fluorene (FDAP), 4' - (phenylmethylene) bis (2-isopropylaniline) (PTBA) and 2- (4-aminophenyl) -5-aminobenzoxazole (BOA) organic compounds having strong electronegativity or asymmetric rigid structure, and the monomer structural formula is as follows:

、

、

、

、

and the like.

Further, the molar ratio of MPD to aromatic diamine is (50 to 97): (3 to 50).

Further, the organic solvent includes one of N, N-dimethylacetamide (DMAc), N-Dimethylformamide (DMF), N-methylpyrrolidone (NMP), and Dimethylsulfoxide (DMSO).

Further, the molar ratio of the total mole of the m-phenylenediamine and the aromatic diamine to the IPC is 1 (1) - (1.05), wherein the addition amount of the IPC is the total addition amount of the IPC added in three batches.

Further, the reaction temperature of the added IPC of the first batch is controlled to be 25-35 ℃, the stirring speed is 500-800 r/min, and the viscosity of the system solution after the reaction at the stage is finished is 0.1-0.3 Pa.s; after the second batch of IPC is added, the reaction temperature is controlled to be 35-45 ℃, the stirring speed is 400-600 r/min, and the viscosity of the system solution after the reaction at the stage is finished is 6-20 Pa.s; after the third batch of IPC is added, the reaction temperature is controlled to be 45-65 ℃, the stirring speed is 200-300 r/min, the viscosity of the system solution after the reaction at the stage is finished is 50-80 Pa.s, and the viscosity of the system solution after the neutralization by adding a neutralizing agent is 30-60 Pa.s.

Further, the neutralizing agent includes one of ammonia, calcium hydroxide and sodium hydroxide.

Further, the low-molecular-weight L-PMIA has a weight-average molecular weight of 8000 to 30000.

Further, the weight average molecular weight of the high molecular weight H-PMIA is 200000 to 300000.

Furthermore, the adding amount of the low molecular weight L-PMIA accounts for 3-9 wt% of the total weight of the slurry.

Further, the slurry is colorless and transparent.

Further, in the second step, the roughness Ra of the steel strip is less than 0.2 μm; the high-temperature treatment temperature is 120-150 ℃; the high-temperature treatment time is 1min to 20min; the temperature of the drying box is 130-200 ℃; the time in the drying box ranges from 3min to 10min; the content of the organic solvent in the dried film is 0.5-1.5%, and the biaxial tension ratio is 1.05-3.0.

Further, in the double-drawing shaping procedure, the film is subjected to bidirectional drawing by regulating and controlling the temperature and the drawing ratio; the temperature is regulated and controlled by adopting subareas, and 8 areas are shared, wherein the 1 st area is a temperature rise transition area, and the temperature is controlled to be 100-120 ℃; the 2 nd area is a temperature stabilizing area, and the temperature is controlled to be 120-135 ℃; the 3 rd zone is a stretching first zone, and the temperature is controlled to be 150-180 ℃; the 4 th area is a stretching second area, and the temperature is controlled to be 180-200 ℃; the 5 th area is a stretching three area, and the temperature is controlled to be 250-300 ℃; the 6 th area is a shaping area, and the temperature is controlled to be 240-270 ℃; the 7 th area is a cooling transition area, the temperature is controlled to be 150-180 ℃, the 8 th area is a cooling area, and the temperature is controlled to be 100-130 ℃;

Further, the transmittance of the prepared polyisophthaloyl metaphenylene diamine film reaches 91-95 percent; the molecular orientation degree of the polyisophthaloyl metaphenylene diamine film is 40-60%, the transverse and longitudinal directions of the tensile strength of the polyisophthaloyl metaphenylene diamine film are more than 110MPa, and the transverse and longitudinal directions of the elongation are more than 10%; the haze value of the polyisophthaloyl metaphenylene diamine film is less than 0.8%, and the yellowness index of the polyisophthaloyl metaphenylene diamine film is less than 1.3; the content of the solvent in the polyisophthaloyl metaphenylene diamine film is less than 200ppm; the thickness of the polyisophthaloyl metaphenylene diamine film is 8-180 mu m.

Example 1

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg of DMAc according to a molar ratio of 97 to obtain a mixed solution, keeping the temperature of the mixed solution at 25 ℃, then starting to add IPC (the molar ratio of IPC to the total molar weight of m-phenylenediamine and aromatic diamine is 1.02; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 30min, and keeping the solution viscosity at 12 pas; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at a speed of 200r/min, reacting for 10min, finally reaching 61 Pa & s of solution viscosity at the stage, adding calcium hydroxide to neutralize the solution to a pH range of 7.5, wherein the viscosity of the system solution after neutralization is 40Pa & s, the weight-average molecular weight of the obtained high-molecular weight H-PMIA is 281000, and mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 10000 to obtain slurry, wherein the L-PMIA accounts for 5wt% of the slurry.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min, wherein the content of the organic solvent in the film after the film is discharged from the drying oven is 0.82%. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 51 mu m.

Example 2

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg of DMAc according to a molar ratio of 95; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min for 40min, and controlling the solution viscosity at the stage to be 15 Pa.s; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally reaching the viscosity of the solution at the stage of 65 Pa.s, adding calcium hydroxide to neutralize the solution until the pH value ranges from 8.0, wherein the viscosity of the system solution after neutralization is 45 Pa.s, obtaining the high molecular weight H-PMIA with the weight average molecular weight of 274000, and then mixing the high molecular weight H-PMIA with L-PMIA with the weight average molecular weight of 10000 to obtain slurry, wherein the L-PMIA accounts for 5wt% of the slurry.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.79% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 53 mu m.

Example 3

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg of DMAc according to a molar ratio of 90; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 35min, and keeping the solution viscosity at 13 pas; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally reaching the solution viscosity of 63 Pa.s at the stage, adding calcium hydroxide to neutralize the solution until the pH value ranges from 7.6, wherein the viscosity of the system solution after neutralization is 44 Pa.s, the weight-average molecular weight of the obtained high-molecular weight H-PMIA is 269000, and then mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 10000 to obtain slurry, wherein the weight ratio of the L-PMIA to the slurry is 5wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.91 percent after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 55 mu m.

Example 4

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg of DMAc according to a molar ratio of 80; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min for 35min, and controlling the solution viscosity at the stage to be 15 Pa.s; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 13min, finally reaching the viscosity of the solution at the stage to 59 Pa.s, adding calcium hydroxide to neutralize the solution until the pH value is 7.6, wherein the viscosity of the system solution after neutralization is 45 Pa.s, the weight-average molecular weight of the obtained high-molecular weight H-PMIA is 284000, and then mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 10000 to obtain slurry, wherein the weight ratio of the L-PMIA to the slurry is 5wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 1.1% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 53 mu m.

Example 5

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg DMAc according to a molar ratio of 70; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min for 35min, and controlling the solution viscosity at the stage to be 12 Pa.s; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 10min, finally reaching the solution viscosity of 66 Pa.s at the stage, adding calcium hydroxide to neutralize the solution until the pH value ranges from 7.7, wherein the viscosity of the system solution after neutralization is 48 Pa.s, the weight-average molecular weight of the obtained high-molecular weight H-PMIA is 271000, and then mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 10000 to obtain slurry, wherein the weight ratio of the L-PMIA to the slurry is 5wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.8% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 51 mu m.

Example 6

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg of DMAc according to a molar ratio of 80; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 30min, and controlling the solution viscosity at 17 pas; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at a speed of 200r/min, reacting for 10min, finally reaching the viscosity of the solution at the stage to 69Pa & s, adding calcium hydroxide to neutralize the solution to a pH range of 8.0, wherein the viscosity of the system solution after neutralization is 49Pa & s, obtaining the high molecular weight H-PMIA with a weight-average molecular weight of 268000, and mixing the high molecular weight H-PMIA with L-PMIA with a weight-average molecular weight of 10000 to obtain slurry, wherein the weight ratio of L-PMIA to the slurry is 5wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 3min, then feeding the film into a drying oven at the temperature of 155 ℃ for 3min, and taking the film out of the drying oven to obtain the film with the organic solvent content of 1.5%. Then, a double-drawing shaping process is carried out, wherein the temperature is controlled to be 100 ℃ in a 1 st transition zone, 120 ℃ in a 2 nd stabilizing zone, the temperature is controlled to be 150 ℃, the first stretching zone is controlled to be 150 ℃, the stretching ratio is 1.05, the second stretching zone is controlled to be 4 ℃, the temperature is controlled to be 180 ℃, the stretching ratio is 1.5, the third stretching zone is controlled to be 5 ℃, the temperature is controlled to be 280 ℃, the stretching ratio is 1.8, the temperature is controlled to be 240 ℃ in a 6 th shaping zone, the temperature is controlled to be 7 ℃ in a 7 th cooling transition zone, the temperature is controlled to be 150 ℃, and the temperature is controlled to be 100 ℃ in a 8 th zone. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 55 mu m.

Example 7

The method comprises the following steps: preparation of slurries

Fully dissolving MPD and FDAP in 425kg of DMAc according to a molar ratio of 80; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 40min, and controlling the solution viscosity at 16 pas; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally reaching the solution viscosity of 66 Pa.s at the stage, adding calcium hydroxide to neutralize the solution until the pH value ranges from 7.6, wherein the viscosity of the system solution after neutralization is 40 Pa.s, the obtained high molecular weight H-PMIA has the weight average molecular weight of 270000, and then mixing the high molecular weight H-PMIA with L-PMIA with the weight average molecular weight of 10000 to obtain slurry, wherein the L-PMIA accounts for 5wt% of the slurry.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating at the temperature of 150 ℃ for 10min, then feeding the film into a drying oven at the temperature of 160 ℃ for 10min, and drying the film for 10min, wherein the content of the organic solvent in the film after the film is discharged from the drying oven is 0.5%. Then, a double-drawing shaping process is carried out, wherein the temperature is controlled to be 120 ℃ in a 1 st transition region, is controlled to be 135 ℃ in a 2 nd stabilizing region, is controlled to be 180 ℃ in a 3 rd drawing first region, is controlled to be 180 ℃ in a drawing ratio of 1.5, is controlled to be 200 ℃ in a 4 th drawing second region, is controlled to be 1.8 in a drawing ratio of 1.8, is controlled to be a 5 th drawing third region, is controlled to be 300 ℃ in a drawing ratio of 3.0, is controlled to be 270 ℃ in a 6 th shaping region, is controlled to be 7 ℃ in a cooling transition region, is controlled to be 180 ℃ in a temperature control region in an 8 th region, and is controlled to be 130 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 55 mu m.

Example 8

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg of DMAc according to a molar ratio of 80; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 30min, and controlling the solution viscosity at the stage to be 6 Pa.s; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 10min, finally enabling the viscosity of the solution in the stage to reach 50 Pa.s, adding sodium hydroxide to neutralize the solution until the pH value ranges from 7.5, enabling the viscosity of the system solution after neutralization to be 30 Pa.s, enabling the weight-average molecular weight of the obtained high-molecular weight H-PMIA to be 264000, and then mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 8000 to obtain slurry, wherein the weight ratio of the L-PMIA to the slurry is 3 wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.6% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 8 mu m.

Example 9

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg of DMAc according to a molar ratio of 97 to obtain a mixed solution, keeping the temperature of the mixed solution at 25 ℃, then starting to add IPC (the molar ratio of IPC to the total molar weight of m-phenylenediamine and aromatic diamine is 1.05; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 30min, and ensuring the solution viscosity to be 18 Pa.s at the stage; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally enabling the viscosity of the solution to reach 70 pas at the stage, adding sodium hydroxide to neutralize the solution until the pH value ranges from 7.8, enabling the viscosity of the system solution after neutralization to be 55 pas, obtaining the high molecular weight H-PMIA with the weight average molecular weight of 277000, and mixing the high molecular weight H-PMIA with L-PMIA with the weight average molecular weight of 30000 to obtain slurry, wherein the weight ratio of L-PMIA to the slurry is 9wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.9% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 52 mu m.

Example 10

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg of DMAc according to a molar ratio of 50; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 35 +/-1 ℃, stirring at 400r/min for 35min, and controlling the solution viscosity at the stage to be 6 Pa.s; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 45 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally enabling the viscosity of the solution in the stage to reach 50 Pa.s, adding calcium hydroxide to neutralize the solution until the pH value is 8.0, enabling the viscosity of the system solution after neutralization to be 30 Pa.s, enabling the obtained high molecular weight H-PMIA to have a weight average molecular weight of 261000, and mixing with L-PMIA with a weight average molecular weight of 10000 to obtain slurry, wherein the weight ratio of L-PMIA to the slurry is 6 wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating at the temperature of 150 ℃ for 20min, then feeding the film into a drying oven at the temperature of 200 ℃ for 3min, and taking the film out of the drying oven to obtain a film with the organic solvent content of 0.5%. Then, a double-drawing shaping process is carried out, wherein the temperature is controlled to be 120 ℃ in a 1 st transition zone, 135 ℃ in a 2 nd stabilizing zone, 180 ℃ in a 3 rd drawing zone, 1.5 in a drawing ratio, 200 ℃ in a 4 th drawing zone, 1.8 in the drawing ratio, a 5 th drawing zone, 300 ℃ in the drawing ratio, 3.0 in a 6 th shaping zone, 270 ℃ in a 7 th cooling transition zone, 180 ℃ in the temperature control, and 130 ℃ in a 8 th cooling zone. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 180 mu m.

Example 11

The method comprises the following steps: slurry preparation

Fully dissolving MPD and FDAP in 425kg of NMP according to a molar ratio of 50 to obtain a mixed solution, keeping the temperature of the mixed solution at 25 ℃, then starting to add IPC (the molar ratio of IPC to the total molar amount of m-phenylenediamine and aromatic diamine is 1.03; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 45 +/-1 ℃, stirring at 600r/min, reacting for 40min, and controlling the solution viscosity at 20 pas at the stage; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 65 +/-2 ℃, stirring at 300r/min, reacting for 15min, finally reaching the viscosity of the solution in the stage to 80 Pa.s, adding calcium hydroxide to neutralize the solution to a pH range of 8.0, wherein the viscosity of the system solution after neutralization is 30 Pa.s, the weight-average molecular weight of the obtained high-molecular weight H-PMIA is 200000, and then mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 8000 to obtain slurry, wherein the L-PMIA accounts for 3wt% of the slurry.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating at 120 ℃ for 6min, then feeding the film into a drying oven at 130 ℃ for 10min, and taking the film out of the drying oven to obtain a film with the organic solvent content of 1.5%. Then, a double-drawing shaping process is carried out, wherein the temperature is controlled to be 100 ℃ in a 1 st transition zone, 120 ℃ in a 2 nd stabilizing zone, the temperature is controlled to be 150 ℃, the first stretching zone is controlled to be 150 ℃, the stretching ratio is 1.05, the second stretching zone is controlled to be 4 ℃, the temperature is controlled to be 180 ℃, the stretching ratio is 1.5, the third stretching zone is controlled to be 5 ℃, the temperature is controlled to be 250 ℃, the stretching ratio is 1.8, the temperature is controlled to be 240 ℃ in a 6 th shaping zone, the temperature is controlled to be 7 ℃ in a 7 th cooling transition zone, the temperature is controlled to be 150 ℃, and the temperature is controlled to be 100 ℃ in a 8 th zone. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 50 mu m.

Example 12

The method comprises the following steps: slurry preparation

Fully dissolving MPD, PTBA and BOA in 425kg of DMSO according to a molar ratio of 70; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 40min, and ensuring the solution viscosity to be 18 Pa.s at the stage; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally enabling the viscosity of the solution in the stage to reach 75 Pa.s, introducing ammonia gas to neutralize the solution until the pH value is 8.0, enabling the viscosity of the system solution after neutralization to be 60 Pa.s, enabling the weight-average molecular weight of the obtained high-molecular weight H-PMIA to be 300000, and mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 30000 to obtain slurry, wherein the weight ratio of L-PMIA to the slurry is 9wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 1min, then feeding the film into a drying oven at the temperature of 155 ℃ for 10min, and taking the film out of the drying oven to obtain the film with the organic solvent content of 0.7%. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 51 mu m.

Example 13

The method comprises the following steps: slurry preparation

Fully dissolving MPD, FDAP and PBTFA in 425kg of NMP according to a molar ratio of 70; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 40min, and ensuring the solution viscosity to be 18 Pa.s at the stage; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 10min, finally enabling the viscosity of the solution in the stage to reach 78 pas, adding calcium hydroxide to neutralize the solution until the pH value ranges from 7.7, enabling the viscosity of the system solution after neutralization to be 56 pas, obtaining the high molecular weight H-PMIA with the weight average molecular weight of 273000, and mixing the high molecular weight H-PMIA with L-PMIA with the weight average molecular weight of 10000 to obtain slurry, wherein the L-PMIA accounts for 5wt% of the slurry.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for drying for 6min, and taking the film out of the drying oven, wherein the content of the organic solvent in the film is 1.1%. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 54 mu m.

Example 14

The method comprises the following steps: slurry preparation

Fully dissolving MPD, FDAP and 1,3,4-APB in 425kg of DMF according to a molar ratio of 80; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min for 40min, and controlling the solution viscosity at the stage to be 15 Pa.s; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally reaching 65 Pa.s of the solution viscosity at the stage, adding calcium hydroxide to neutralize the solution until the pH value ranges from 8.0, wherein the viscosity of the system solution after neutralization is 42 Pa.s, the weight-average molecular weight of the obtained high-molecular weight H-PMIA is 275000, and then mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 10000 to obtain slurry, wherein the L-PMIA accounts for 5wt% of the slurry.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.7% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 50 mu m.

Comparative example 1

The method comprises the following steps: slurry preparation

Fully dissolving MPD in 425kg of DMAc to obtain a mixed solution, keeping the temperature of the mixed solution at 25 ℃, then starting to add IPC (the molar ratio of IPC to the total molar weight of m-phenylenediamine and aromatic diamine is 1.02, the solid content of high molecular weight poly (m-phenyleneisophthalamide) is 15% after the reaction is finished), firstly adding 1/3 of IPC in the first batch, controlling the reaction temperature at 28 +/-1 ℃, stirring at 500r/min, reacting for 15min, and keeping the solution viscosity at 0.22 Pa.s; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 40min, and ensuring the solution viscosity to be 18 pas at the stage; adding 1/3 of the final IPC into the third batch, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, and finally neutralizing the solution to pH 7.5 by adding calcium hydroxide, wherein the viscosity of the neutralized system solution is 51 Pa.s.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.8% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the drawing ratio is 3.0, the temperature is controlled to 145 ℃ in a 1 st transition region, the temperature is controlled to 165 ℃ in a 2 nd stabilizing region, the temperature is controlled to 185 ℃ in a 3 rd drawing region, the temperature is controlled to 168 ℃ in a 4 th shaping region, the temperature is controlled to 135 ℃ in a 5 th cooling transition region, then the process enters trimming, finally annealing and rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 52 mu m.

Comparative example 2

The method comprises the following steps: preparation of slurries

Fully dissolving MPD in 425kg of DMAc to obtain a mixed solution, keeping the temperature of the mixed solution at 25 ℃, then starting to add IPC (the molar ratio of IPC to the total molar weight of m-phenylenediamine and aromatic diamine is 1.02, the solid content of high molecular weight poly (m-phenyleneisophthalamide) is 15% after the reaction is finished), firstly adding 1/3 of IPC in the first batch, controlling the reaction temperature at 28 +/-1 ℃, stirring at 500r/min, reacting for 15min, and keeping the solution viscosity at 0.20 Pa.s; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 30min, and obtaining solution viscosity of 16 pas at the stage; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at a speed of 200r/min, reacting for 10min, finally reaching the viscosity of the solution at the stage to 69 pas, adding calcium hydroxide to neutralize the solution to a pH range of 7.7, wherein the viscosity of the system solution after neutralization is 47 pas, and mixing the obtained high molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 40000 to obtain slurry, wherein the weight ratio of L-PMIA to the slurry is 5wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.9% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 54 mu m.

Comparative example 3

The method comprises the following steps: slurry preparation

Fully dissolving MPD in 425kg of DMAc to obtain a mixed solution, keeping the temperature of the mixed solution at 25 ℃, then starting to add IPC (the molar ratio of IPC to the total molar weight of m-phenylenediamine and aromatic diamine is 1.02, the solid content of high molecular weight poly (m-phenyleneisophthalamide) is 15% after the reaction is finished), firstly adding 1/3 of IPC in the first batch, controlling the reaction temperature at 28 +/-1 ℃, stirring at 500r/min for 25min, and controlling the solution viscosity at the stage to be 0.22 Pa.s; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min, reacting for 40min, and keeping the solution viscosity at 17 pas at the stage; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally reaching the solution viscosity of 71 Pa.s at the stage, adding calcium hydroxide to neutralize the solution until the pH value ranges from 8.0, wherein the viscosity of the system solution after neutralization is 49 Pa.s, the weight-average molecular weight of the obtained high-molecular weight H-PMIA is 271000, and then mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 7000 to obtain slurry, wherein the weight ratio of the L-PMIA to the slurry is 5wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.8% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.3, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.55, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 53 mu m.

Comparative example 4

The method comprises the following steps: slurry preparation

Fully dissolving MPD in 425kg of DMAc to obtain a mixed solution, keeping the temperature of the mixed solution at 25 ℃, then starting to add IPC (the molar ratio of IPC to the total molar weight of m-phenylenediamine and aromatic diamine is 1.02, the solid content of high molecular weight poly (m-phenyleneisophthalamide) is 15% after the reaction is finished), firstly adding 1/3 of IPC in the first batch, controlling the reaction temperature at 28 +/-1 ℃, stirring at 500r/min, reacting for 20min, and keeping the solution viscosity at 0.25 Pa.s; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min for 40min, and controlling the solution viscosity at the stage to be 19 Pa.s; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally reaching the solution viscosity of 69 pas at the stage, adding calcium hydroxide to neutralize the solution until the pH value ranges from 7.8, wherein the viscosity of the system solution after neutralization is 48 pas, and the obtained high molecular weight H-PMIA has the weight-average molecular weight of 262000 and is then mixed with L-PMIA with the weight-average molecular weight of 10000 to obtain slurry, wherein the weight ratio of L-PMIA to the slurry is 5wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.7% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.3, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 3.0, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 50 mu m.

Comparative example 5

The method comprises the following steps: slurry preparation

Fully dissolving MPD in 425kg of DMAc to obtain a mixed solution, keeping the temperature of the mixed solution at 25 ℃, then starting to add IPC (the molar ratio of IPC to the total molar weight of m-phenylenediamine and aromatic diamine is 1.02, the solid content of high molecular weight poly (m-phenyleneisophthalamide) is 15% after the reaction is finished), firstly adding 1/3 of IPC in the first batch, controlling the reaction temperature at 28 +/-1 ℃, stirring at 500r/min, reacting for 25min, and keeping the solution viscosity at 0.23 Pa.s; adding 1/3 of IPC in the second batch, controlling the reaction temperature at 42 +/-1 ℃, stirring at 400r/min for 40min, and controlling the solution viscosity at 17 pas; adding 1/3 of the last IPC into the third batch of IPC, controlling the reaction temperature at 58 +/-2 ℃, stirring at 200r/min, reacting for 15min, finally reaching the viscosity of the solution at the stage of 66 Pa.s, adding calcium hydroxide to neutralize the solution until the pH value ranges from 7.5, wherein the viscosity of the system solution after neutralization is 45 Pa.s, the weight-average molecular weight of the obtained high-molecular weight H-PMIA is 284000, and then mixing the high-molecular weight H-PMIA with L-PMIA with the weight-average molecular weight of 10000 to obtain slurry, wherein the weight ratio of the L-PMIA to the slurry is 5wt%.

Step two: membrane preparation

And (3) casting the slurry obtained in the step one on a steel belt to form a film, removing the solvent by high-temperature treatment for forming, heating the film at the temperature of 140 ℃ for 6min, then feeding the film into a drying oven at the temperature of 155 ℃ for 6min, and drying the film for 6min to obtain the film with the organic solvent content of 0.97% after the film is discharged from the drying oven. Then, the process enters a double-drawing shaping process, wherein the temperature control in a 1 st transition zone is 115 ℃, the temperature control in a 2 nd stabilizing zone is 130 ℃, the temperature control in a 3 rd drawing first zone is 155 ℃, the drawing ratio is 1.6, the temperature control in a 4 th drawing second zone is 185 ℃, the drawing ratio is 1.9, the temperature control in a 5 th drawing third zone is 280 ℃, the drawing ratio is 2.5, the temperature control in a 6 th shaping zone is 255 ℃, the temperature control in a 7 th cooling transition zone is 165 ℃, the temperature control in a 8 th zone is 125 ℃. Then, the edge cutting is carried out, finally, the annealing and the rolling are carried out, and the thickness of the prepared polyisophthaloyl metaphenylene diamine film is 50 mu m.

Table 1 shows the comparison of the film property data of the examples and comparative examples, and the test methods of the film samples obtained in the examples and comparative examples are as follows: the thickness is measured by a thickness gauge, and 5 data measured by each sample are averaged; the breaking strength and the elongation are tested by a universal tensile machine, the tensile rate is 20mm/min, 3 samples are respectively cut from each sample in the longitudinal direction (MD) and the Transverse Direction (TD), the size of each sample is 15mm × 180mm, and the test result is the average value of the 3 samples; the transmittance and the haze are tested by a standard haze meter, and 3 data of each sample are averaged; the yellowness index is tested by adopting a yellowness index instrument; testing the crystallinity by an XRD method; the orientation degree is tested by adopting an SAXS method, and the scanning range 2 theta is less than 5 degrees; the solvent content was extracted with acetone, and then the average of 3 measurements per sample was determined by gas chromatography.

It can be seen from table 1 that the polyisophthaloyl metaphenylene diamine of the present invention is modified in molecular structure and then mixed with polyisophthaloyl metaphenylene diamine with a certain low molecular weight to prepare a film-making slurry, and the crystal nucleus structure and orientation of L-PMIA are controlled in a double-drawing process to provide beneficial effects on film performance, and the transmittance of examples 4 to 7 is more than 94%, and the transverse and longitudinal rupture strength of the film is more than 120MPa, the crystallinity is about 30%, and the orientation is about 50% in examples 4 to 6. The polyisophthaloyl metaphenylene diamine has excellent insulating property and high temperature resistance, and the high-transparency polyisophthaloyl metaphenylene diamine film prepared by the method can meet the application in the field of flexible electronic devices by carrying out molecular design on the polyisophthaloyl metaphenylene diamine and researching a film preparation process.

According to the invention, an asymmetric structure or a rigid planar structure, also called as a large substituent group, is introduced into polyisophthaloyl metaphenylene diamine, so that the CTC effect is greatly reduced, a colorless transparent polymer solution is obtained, L-PMIA is added into film-making slurry to accelerate the formation of crystal nuclei, a nucleating agent similar to the main body structure is formed, the crystallization rate of the main body is improved, and the mechanical property and the transparency of the film can be improved. The draw ratio of the first and second draw zones during double drawing is such that it has a significant effect on the crystallization and orientation of the film, otherwise it has a negative effect on the film properties.

TABLE 1 comparison of film Performance data for examples and comparative examples

The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner; those of ordinary skill in the art can readily implement the present invention in view of the exemplary embodiments set forth herein and as set forth above; however, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the scope of the invention; meanwhile, any changes, modifications, and evolutions of the equivalent changes of the above embodiments according to the actual techniques of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a high-transmittance polyisophthaloyl metaphenylene diamine film is characterized by comprising the following steps of,

s2, adding low-molecular-weight polyisophthaloyl metaphenylene diamine into the high-molecular-weight polyisophthaloyl metaphenylene diamine polymer solution to prepare slurry, and obtaining a polyisophthaloyl metaphenylene diamine film with high transmittance after tape casting, drying, stretching, heat setting treatment, annealing and rolling;

the molar ratio of the m-phenylenediamine to the aromatic diamine is (50 to 97) (3 to 50), and the molar ratio of the total mole of the m-phenylenediamine and the aromatic diamine to the isophthaloyl dichloride is (1); the addition amount of the low-molecular-weight polyisophthaloyl metaphenylene diamine in the slurry accounts for 3-9 wt% of the total amount;

the specific process for preparing the polyisophthaloyl metaphenylene diamine film in the S2 comprises the following steps:

in the double-drawing shaping process, the film is subjected to bidirectional drawing by regulating and controlling the temperature and the drawing ratio; the temperature is regulated and controlled by adopting subareas, and 8 areas are shared, wherein the 1 st area is a temperature rise transition area, and the temperature is controlled to be 100-120 ℃; the 2 nd area is a temperature stabilizing area, and the temperature is controlled to be 120-135 ℃; the 3 rd zone is a stretching first zone, and the temperature is controlled to be 150-180 ℃; the 4 th area is a stretching second area, and the temperature is controlled to be 180-200 ℃; the 5 th area is a stretching three area, and the temperature is controlled to be 250-300 ℃; the 6 th area is a shaping area, and the temperature is controlled to be 240-270 ℃; the 7 th area is a cooling transition area, the temperature is controlled to be 150-180 ℃, the 8 th area is a cooling area, and the temperature is controlled to be 100-130 ℃;

the stretch ratio of the first stretch zone in the 3 rd zone is 1.05 to 1.5, the stretch ratio of the second stretch zone in the 4 th zone is 1.5 to 1.8, and the stretch ratio of the third stretch zone in the 5 th zone is 1.8 to 3.0;

the aromatic diamine comprises one or a mixture of more than two of 4- (4 '-aminophenoxy) -3, 5-bis (trifluoromethane) aniline, 1, 3-bis (4-aminophenoxy) benzene, 9-bis (4-aminophenyl) fluorene, 4' - (phenylmethylene) bis (2-isopropylaniline) and 2- (4-aminophenyl) -5-aminobenzoxazole;

the weight average molecular weight of the low-molecular-weight polyisophthaloyl metaphenylene diamine is 8000-30000, and the weight average molecular weight of the high-molecular-weight polyisophthaloyl metaphenylene diamine is 200000-300000.

2. The method according to claim 1, wherein the pH of the polymer solution of high molecular weight polyisophthaloyl metaphenylene diamine after neutralization with the neutralizing agent is 7 to 8.5.

3. The method for preparing a high-transmittance polyisophthaloyl metaphenylene diamine film according to claim 1, wherein the specific process for preparing the high molecular weight polyisophthaloyl metaphenylene diamine polymer solution in S1 is as follows:

dissolving m-phenylenediamine and aromatic diamine in an organic solvent according to a preset proportion, adding m-phthaloyl chloride in three batches for polycondensation reaction, adding a neutralizing agent after the reaction is finished for neutralization to obtain a polymer solution of poly (m-phenyleneisophthalamide) with high molecular weight, wherein the system viscosity is 30-60 Pa.s;

4. The method of claim 1, wherein in the step of preparing the polyisophthaloyl metaphenylene diamine film in S2,

the roughness Ra of the steel strip is less than 0.2 mu m;

the drying temperature is 130-200 ℃, the drying time is 3-10min, and the content of the organic solvent in the dried film is 0.5-1.5 wt%.

5. The method as claimed in claim 1, wherein the neutralizer is one of ammonia, calcium hydroxide and sodium hydroxide.

6. The method as claimed in claim 1, wherein the organic solvent comprises one of N, N-dimethylacetamide, N-dimethylformamide, N-methylpyrrolidone and dimethylsulfoxide.

7. A high-transmittance polyisophthaloyl metaphenylene diamine film produced by the method for producing a high-transmittance polyisophthaloyl metaphenylene diamine film according to any one of claims 1 to 6, characterized in that the polyisophthaloyl metaphenylene diamine film has a transmittance of 91% to 95%.

8. The high-transmittance polyisophthaloyl metaphenylene diamine film according to claim 7, wherein the molecular orientation degree of the polyisophthaloyl metaphenylene diamine film is 40% -60%, the tensile strength of the polyisophthaloyl metaphenylene diamine film is larger than 110MPa in the transverse and longitudinal directions, and the elongation of the polyisophthaloyl metaphenylene diamine film is larger than 10% in the transverse and longitudinal directions; the haze value of the polyisophthaloyl metaphenylene diamine film is less than 0.8%, and the yellowness index of the polyisophthaloyl metaphenylene diamine film is less than 1.3; the content of the solvent in the polyisophthaloyl metaphenylene diamine film is less than 200ppm; the thickness of the polyisophthaloyl metaphenylene diamine film is 8-180 mu m.