JP7345806B2 - Anthraquinone derivative tetraamine monomer, true black polyimide derived therefrom and method for preparing the same - Google Patents

Description

The present application relates to the technical field of organic synthesis, and in particular, the present application relates to an anthraquinone derivative tetraamine monomer, a method for preparing an anthraquinone derivative tetraamine monomer, a true black polyimide derived from the anthraquinone derivative tetraamine monomer, and a true black polyimide derived from the anthraquinone derivative tetraamine monomer. It relates to a method for preparing.

Black polyimide (PI) film has properties such as opacity, low light absorption, low light transmittance, and low light reflection coefficient, and has important application value in the following fields. (1) Flexible circuit board (FPC) board film: black can effectively block light and prevent the circuit design from being cracked by competitors, and black is a simple color, further meeting the requirements of concise aesthetics. Match; (2) Lithium battery: Insulating protection for lithium battery pack connecting parts, black polyimide can block light and prevent copper oxidation; (3) Wireless charging: For wireless charging, as insulation protection for the coil. Ultra-thin black polyimide film adhesive is required, but currently black polyimide cannot meet the requirements, so regular polyimide coated with carbon black is temporarily used; (4) Aerospace: Satellite When used in antennas, it can eliminate or avoid interference of various stray lights to imaging systems and sensors; as a light-absorbing film, it can be used to create optical fixed attenuators and optical terminators.

Currently, there are three main methods for preparing black PI films. (1) A method of adding graphene, perylene black, and other organic and inorganic fillers; (2) A method of using special monomers to increase the formation of charge transfer complexes of polyimide molecular chains. For example, Liu et al. (J Polym Res (2019) 26:171) copolymerized using an electron-rich aromatic diamine monomer, 4,4'-diaminodiphenylamine (NDA), and PMDA, but 100% NDA Even after using , the color of the polymer was still not black. Therefore, the black color of polyimide due to conjugation is completely unattainable, and the use of large amounts of special monomers increases the cost of black polyimide films. Furthermore, the Chinese invention patent application with publication number CN109180936A adopted a copolymerization method with commercially available diamines and prepared a series of true black polyimides by adjusting the blending ratio of both. The Chinese invention patent application with publication number CN111574426A designed and synthesized a diamine monomer containing isoindigo structure and homopolymerized it with commercially available dianhydride to prepare a series of true black polyimides.
However, the above method for preparing black polyimide has some drawbacks as follows.

1. The preparation process is complex and both require pre-modification of the filler to make it more uniformly dispersed in the PI matrix to avoid non-uniform mechanical properties and pinholes.

2. Although the introduction of inorganic fillers can improve the mechanical and thermal properties of PI films to some extent, it destroys the insulation properties and breakdown strength of PI films, which has a negative impact on the application in electronic industry.

3. The introduction of organic pigments can avoid affecting the electrical properties of PI films, but the low thermal decomposition temperature prevents the use of PI films in high temperature areas, and they are easily decomposed by environmental factors, resulting in poor weather resistance. poor.
4. Existing true black polyimide still lacks light transmittance, and cannot guarantee less than 1% in the entire visible light band.
Therefore, there continues to be a need in the art to develop true black polyimides and methods for their preparation.

The purpose of this application is to provide a novel anthraquinone derivative monomer with a high molar extinction coefficient, and by introducing multiple auxochrome groups into the anthraquinone structure, its absorption wavelength is spread over a wide range, thereby solving the above technical problems. Solvable.
It is also an object of the present application to provide a method for the preparation of anthraquinone derivative tetraamine monomers.
It is also an object of the present application to provide true black polyimides synthesized by using anthraquinone derivative tetraamine monomers.
It is also an object of the present application to provide a method for the preparation of true black polyimide.

In order to solve the above technical problem, this application provides the following technical solution.
In a first aspect, the present application provides an anthraquinone derivative tetraamine monomer characterized in having a structure represented by general formula I below.

In one embodiment, only two amine groups in the anthraquinone derivative tetraamine monomer can undergo a polycondensation reaction, so that a linear polymer can be obtained.

In a second aspect, the application provides a method for preparing an anthraquinone derivative tetraamine monomer according to the first aspect, which method comprises: 1,8-dihydroxy-9 , 10-anthraquinone to 1,8-dihydroxy-2,4,5,7-tetranitro-9,10-anthraquinone, followed by reduction of the nitro group to the amino group to form 1,8-dihydroxy-2,4 , 5,7-tetraamino-9,10-anthraquinone.

In another embodiment, the present application provides a method for preparing an anthraquinone derivative tetraamine monomer according to the first aspect, the method comprising: 1,8-dihydroxy- 4,5-dinitro-9,10-anthraquinone is nitrated to 1,8-dihydroxy-2,4,5,7-tetranitro-9,10-anthraquinone, followed by reduction of the nitro group to an amino group, and 1, The method is characterized by comprising obtaining 8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone.

In a third aspect, the present application provides an anthraquinone derivative according to the first aspect comprising a structural unit derived from a tetraamine monomer, a structural unit derived from a diamine monomer, and a structural unit derived from an acid anhydride monomer. In the true black polyimide, the structural unit derived from the anthraquinone derivative tetraamine monomer accounts for 4% or more of the total number of moles of the structural unit derived from the anthraquinone derivative tetraamine monomer and the structural unit derived from the diamine monomer. A true black polyimide is provided. In a preferred embodiment, the structural unit derived from the anthraquinone derivative tetraamine monomer accounts for 4% to 80% of the total number of moles of the structural unit derived from the anthraquinone derivative tetraamine monomer and the structural unit derived from the diamine monomer. occupies In a preferred embodiment, the structural unit derived from the anthraquinone derivative tetraamine monomer accounts for 4% to 10% of the total number of moles of the structural unit derived from the anthraquinone derivative tetraamine monomer and the structural unit derived from the diamine monomer. occupy

In an embodiment of the first aspect, the total number of moles of amine groups involved in the reaction of the anthraquinone derivative tetraamine monomer and the diamine monomer, and the carboxylic acid anhydride group involved in the reaction of the acid anhydride monomer. to the total moles is 1:1. In this embodiment, due to the presence of intramolecular hydrogen bonds in the anthraquinone derivative tetraamine monomer, the amine groups at the ortho and para positions have different activities, and only the amine groups at the two ortho positions participate in the copolymerization reaction. can.

In one embodiment of the first aspect, the acid anhydride monomer is 4,4'-(acetylene-1,2-diyl)diphthalic anhydride, pyromellitic dianhydride, 3,3',4, 4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2'-bis(3,4-dicarboxylic acid)hexafluoropropane dianhydride, 4,4'-oxydiphthalic anhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, naphthalene-1 , 4,5,8-tetracarboxylic dianhydride, and diphenyl sulfide dianhydride.

In one embodiment of the first aspect, the diamine monomer is m-phenylenediamine, p-phenylenediamine, 4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4 , 4'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-diamino-2, 2'-dimethylbiphenyl, 2-(4-aminophenyl)-5-aminobenzoxazole, 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminophenoxy)benzene, 1 , 3-bis(3-hydroxy-4-aminophenoxy)benzene, 2-(4-aminophenyl)-6-aminobenzoxazole, 2,2-p-phenyl-bis(5-aminobenzoxazole) and 2, One or more of 2'-p-phenyl-bis(6-aminobenzoxazole).
In a fourth aspect, the application provides a method for preparing a true black polyimide according to the third aspect, characterized in that said method comprises the following steps.

(1) Under anhydrous and oxygen-free conditions, the anthraquinone derivative tetraamine monomer and diamine monomer described in the first embodiment are mixed at a predetermined weight ratio, stirred until dissolved to form a uniform solution, and then After adding the acid anhydride monomer, stirring and reacting for a given time in a cold water bath, a black polyamic acid solution is obtained;
(2) Imidize the black polyamic acid solution to obtain true black polyimide.

In an embodiment of the fourth aspect, the imidization of the black polyamic acid solution is carried out by uniformly applying the black polyamic acid solution to a dry and clean glass plate by an automatic film coating machine after defoaming. The imidization reaction is carried out by a thermal imidization method such that the temperature curing procedure is 80° C./3 hours, 100° C./1 hour, 200° C./2 hours, and 300° C./4 hours.

Compared with the prior art, the beneficial effects of the present application are that the black polyimide of the present application has good light shielding performance, good mechanical properties, thermal stability and dielectric properties, and has high light transmittance in the whole wavelength band. is less than 1%.

FIG. 1 shows the ultraviolet absorption spectrum of the anthraquinone derivative tetraamine monomer according to Example 1. FIG. 2 shows the infrared spectrum of the anthraquinone derivative tetraamine monomer according to Example 1. FIG. 3 shows the hydrogen nuclear magnetic spectrum of the anthraquinone derivative tetraamine monomer according to Example 1. Figure 4 shows an optical photograph of the polyimide according to Example 3 on white A4 paper.

Black polyimide has aroused the interest of many domestic and international research teams because of its wide potential application prospects. For example, a Chinese invention patent with publication number CN105860112B claims that by blending a PI precursor polyamic acid (PAA) solution with a polyacrylonitrile solution, both the excellent mechanical properties of PI and an opaque black film after PAN preoxidation can be obtained. It was disclosed that a black film having the following properties can be obtained. A Chinese invention patent with publication number CN105482115B reported a method of forming a film by adding a black filler such as carbon black or carbon fiber powder and a coupling agent to a polyamic acid solution, then defoaming and casting. A Chinese invention patent application with publication number CN108017910A reported a method of forming a film by adding carbon black pigment to a polyamic acid solution, adding a flocculant after filtration, and then defoaming and casting. The Chinese invention patent application with publication number CN110387040A describes conductive nanoparticles such as transition metal nitrides, transition metal carbides, transition metal borides and noble metals, as well as graphene, carbon-based nanomaterials, black pigments, black dyes, etc., in a polyamic acid solution. We reported a method of forming a film by adding it to the water, degassing it, and then casting it, which significantly improved the shielding properties. The Chinese invention patent application with publication number CN108976447A reported a method to prepare ultrathin black polyimide films by adding carbon black with different particle sizes to a polyamic acid solution and then defoaming and coating.

True black polyimide not only has excellent light-shielding properties, but also its mechanical, thermal, and electrical properties can be improved by adjusting the type and amount of monomer used. Therefore, it is very important to continue developing new methods for preparing true black polyimides.
In one embodiment, the present application provides novel anthraquinone derivative tetraamine monomers having the structure represented by general formula I below.

In one embodiment, the present application provides a method for preparing the above-described anthraquinone derivative tetraamine monomer, which method comprises preparing 1,8-dihydroxy-9,10-anthraquinone in the presence of concentrated sulfuric acid and concentrated nitric acid. Nitration to 8-dihydroxy-2,4,5,7-tetranitro-9,10-anthraquinone followed by reduction of the nitro group to the amino group to give 1,8-dihydroxy-2,4,5,7-tetraamino -9,10-anthraquinone.

In another embodiment, a method for preparing an anthraquinone derivative tetraamine monomer comprises converting 1,8-dihydroxy-4,5-dinitro-9,10-anthraquinone into -2,4,5,7-tetranitro-9,10-anthraquinone, followed by reduction of the nitro group to the amino group to give 1,8-dihydroxy-2,4,5,7-tetraamino-9, Including obtaining 10-anthraquinone.

In one embodiment, the present application also provides a true black polyimide formed by reacting the anthraquinone derivative tetraamine monomer, diamine monomer, and acid anhydride monomer. In such embodiments, the content of anthraquinone derivative tetraamine monomers is preferably 4% or more of the total moles of all amine monomers. In a first aspect, when the content of anthraquinone derivative tetraamine monomer is less than 4% of the total moles of all amine monomers, the prepared polyimide exhibits a yellow to dark green color rather than a pure black color. In another aspect, when the content of anthraquinone derivative tetraamine monomer exceeds 10% of the total moles of all amine monomers, the LAB value of the resulting true black polyimide film does not change appreciably. Therefore, in one preferred embodiment, the content of anthraquinone derivative tetraamine monomers is preferably 4%-10% of the total moles of all amine monomers.

The present application also includes first reacting an anthraquinone derivative tetraamine monomer, a diamine monomer and an acid anhydride monomer to obtain a polyamic acid solution, and then imidizing the polyamic acid solution to obtain a true black polyimide. The present invention relates to a method for preparing the black intrinsic polyimide.
Example

The present application is further described and explained below with reference to examples. Unless otherwise specified, all chemical raw materials used can be purchased from the market. Those skilled in the art can understand that the following examples are merely illustrative.
In the examples below, the characterization methods used are as follows.
Hydrogen nuclear magnetic resonance spectrum ( ¹ H NMR):

Nuclear magnetic resonance ( ¹ H NMR) spectra of reaction products and intermediates are obtained on a Bruker AVANCE III HD 400/500, Germany. Sample preparation method: In a clean, dry glass NMR tube, completely dissolve approximately 10 mg of sample in approximately 0.5 mL of deuterated reagent. Highly soluble products dissolve in deuterated chloroform (CDCl ₃ ) as a solvent at room temperature, while less soluble products use deuterated dimethyl sulfoxide (DMSO-d6) as a solvent. DMSO-d6 tends to solidify at lower room temperatures and needs to be blown with a hair dryer before adding the sample. When tested at room temperature, tetramethylsilane (TMS) is used as an internal standard and the chemical shift is 0 ppm.
Fourier transform infrared spectroscopy (FT-IR):

In a dry environment, the ATR mode of a Nicolet iS5 (ThermoFisher Scientific, Inc., USA) Fourier Transform Infrared Spectrometer (FTIR) was used for testing, and before testing, the monomer (4NADA) was first placed in a vacuum oven at 80 °C. Leave for 2 hours to remove moisture. The scan range is set to 4000-650 cm ⁻¹ , the resolution is set to 2 cm ⁻¹ , and the number of scans is set to 32, and the average value is automatically obtained.
Ultraviolet-visible spectrum (UV-Vis):

The light transmittance of the true black polyimide film is analyzed with a Japan Shimadzu UV-2600 spectrophotometer, and the scanning range is set at 360-800 cm ^-1 . The UV absorbance of the monomer is also analyzed on a Japan Shimadzu UV-2600 spectrophotometer to detect the absorbance of the dilute solution. The monomer concentration is 30 μM and the solvent of choice is N,N-dimethylformamide.
CIELAB color space:

The reflectance of the prepared true black polyimide film is tested on a LAMBDA950 UV/Vis/NIR spectrophotometer from PerkinElmer Company, USA. By combining the built-in transformation formula with the relative spectral function distribution of the CIE standard illuminant D65 used and the CIE 1976 standard chromaticity observer, the L ^* , a ^* , b ^* parameter values are obtained by the gamut transformation calculation. The light source employed is a standard light source D65, and the observation angle is 10°.
Thermal performance analysis (TGA & DMA & TMA):

Thermogravimetric analysis of true black polyimide films was performed on a TA Discovery 550 thermogravimetric analyzer (TGA) under nitrogen protection, gas flow rate was 50 mL/min, and temperature was increased from room temperature to 120 °C at 20 °C/min. After increasing and staying for 15 minutes, the temperature was increased from 50°C to 800°C at 10°C/min.

Glass transition temperature (Tg) was performed on a TA Q800 dynamic thermomechanical analyzer (DMA) by cutting the true black polyimide film into rectangular strips of equal width (0.5 cm) and setting the loading frequency to 1 Hz. , the temperature is increased from 30°C to 500°C at a rate of 5°C/min under nitrogen protection.

The thermal dimensional stability of the true black polyimide film was analyzed on a TAQ 400 thermomechanical analyzer (TMA) in tensile mode by measuring the change in strip size with increasing temperature. A true black polyimide film was prepared into a long strip with a uniform width (0.5 cm), the static load was 0.05 N, the temperature increase rate was 10 °C/min, the temperature increase range was from room temperature to 400 °C, and the nitrogen flow rate was 50 mL. /min. The programmed heating step is divided into two parts, the first step is heating at the same rate and then cooling to remove the residual internal stress of the film during thermal imidization; Step records curve data for heating up to 400°C.
Mechanical property analysis:

The mechanical properties of the true black polyimide film were measured by Sansi Taijie SUST CMT1104 electronic universal testing machine. Samples were cut into 1 cm wide rectangular strips, the pulling speed was 5 mm/min, and multiple valid test results were averaged according to ASTM D882-02 test standard.
Dielectric performance analysis:

The dielectric properties of the true black polyimide film were measured by a Canadian Keysight N5227B network analyzer, and rectangular samples with side lengths greater than 3*4 mm were prepared to test the dielectric constant and dielectric loss. After drying the sample at 80° C. for 2 hours, it was placed on the sensor, a test frequency was selected, and the test was performed. The test frequencies were 24 GHz, 40 GHz, and 60 GHz, the sample thickness was 25 microns, and the medium was air.
Monomer synthesis example Example 1

Add 1,8-dihydroxy-9,10-anthraquinone (1.0 mmol) to a three-necked flask, add 5 ml of concentrated sulfuric acid and 4 ml of concentrated nitric acid at 0°C, stir vigorously for 4 hours, and add crushed ice. The solvent was removed by suction filtration and the solid material was washed with water/saturated sodium bicarbonate solution and dried in vacuo overnight to give a yellow crude product 1.

The crude product 1 was purified by silica gel chromatography (short column) eluting with eluent (methanol) to give the yellow product 1,8-dihydroxy-2,4,5,7-tetranitro-9,10 - Obtained anthraquinone.

The above yellow product (1 mmol) was weighed and dissolved in ethanol in a flask, and Na ₂ S.9H ₂ O (8 mmol) was weighed and dissolved with distilled water to saturation, and added to the flask. The mixture was allowed to react under reflux for 12 hours; after cooling to room temperature, it was poured into the prepared ice-water mixture with constant stirring. After filtration, it was washed with water and dried under vacuum overnight to obtain a black desired product, 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone.

The ultraviolet absorption spectrum and infrared spectrum of the above monomer were measured, and the results are shown in FIGS. 1 and 2, respectively. As shown in Figure 1, the monomer exhibits strong absorption in the visible light band of 400-700 nm, and at the same time, the half-value width reaches nearly 150 nm.Coupled with its own planar conjugated structure and the influence of intramolecular hydrogen bonds, the monomer It will appear black. As shown in Fig. 2, the infrared absorption peak at 3500-3200 cm ^-1 can belong to the ortho-amino group and the para-amino group in turn, and both the peak shift and the peak broadening are due to the intramolecular hydrogen bond in the latter. This shows that there is a difference in reactivity between the two amino groups. At the same time, the carbonyl peak appearing at 1567 cm ⁻¹ also indicates that there are various hydrogen bonds within the molecule, that is, the carbonyl group forms intramolecular hydrogen bonds with the hydroxyl group and the para-amino group. Due to this unusual hydrogen bond, the carbonyl peak that normally appears around 1700 cm ^-1 was lowered to 1567 cm ^-1 .
This difference in activity between amino groups is also confirmed in Figure 3, i.e. the NMR peak of ortho-amino hydrogen appears at higher magnetic fields.
The molar extinction coefficient of 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone according to Example 1 was also determined.

The method for calculating the molar extinction coefficient is as follows.
The molar extinction coefficient refers to the extinction coefficient when the concentration is 1 mol/L, and is expressed by ε. The calculation formula is as follows.
Here, A is the ultraviolet absorbance measured with an ultraviolet spectrophotometer, ε is the molar extinction coefficient, b is the thickness of the absorption cell, and c is the molar concentration of the liquid to be measured.

Therefore, when combined with the ultraviolet absorption spectrum of 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, the molar extinction coefficient at the maximum absorption wavelength λmax is approximately 10 ⁵ L/(mol・cm), where the molar concentration of the liquid to be measured is 30 μM, the thickness of the absorption cell is 1 cm, the absorbance at the maximum absorption wavelength is 0.296, and the diluted solution is still a deep blue color. It can be seen that the molar extinction coefficient is sufficiently strong.
Example 2

Add 1,8-dihydroxy-4,5-dinitro-9,10-anthraquinone (1.0 mmol) to a three-necked flask, add 3 ml of concentrated sulfuric acid and 2 ml of concentrated nitric acid at 0°C, and stir vigorously mechanically for 4 hours. After that, it was poured onto crushed ice, the solvent was removed by suction filtration, the solid material was washed with water/saturated sodium bicarbonate solution and dried in vacuo overnight to give the yellow crude product 1.

The crude product 1 was dissolved in methanol and then recrystallized by adding cyclohexane to obtain the yellow product 1,8-dihydroxy-2,4,5,7-tetranitro-9,10-anthraquinone.

The above yellow product (1 mmol) was weighed and dissolved in N,N-dimethylformamide in a flask, and 0.01 g of palladium on carbon was weighed and added to the flask. The mixture was reacted at reflux for 12 hours at standard atmospheric pressure under a hydrogen atmosphere; after cooling to room temperature, it was poured into prepared water with constant stirring. After filtration, it was washed with water and dried under vacuum overnight to obtain a black desired product, 1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone.
The ultraviolet absorption spectrum and infrared spectrum of the above monomer were measured, and the results are shown in FIGS. 1 and 2, respectively.
The purification and reduction means described above can be used interchangeably with the purification and reduction means of Example 1.

Example of preparation of true black polyimide Example 3
This example relates to the synthesis of true black polyimide PI-1.

1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, ODA (4,4'-diaminodiphenyl ether), and PMDA (pyromellitic dianhydride) in a molar ratio of 4:96. A black polyimide film was prepared using the same method as described above, and the solids content was 15.3%. The ratio of the total number of moles of amine groups involved in the reaction of the anthraquinone derivative tetraamine monomer and the diamine monomer to the total number of moles of carboxylic acid anhydride groups involved in the reaction of the acid anhydride monomer is 1: It was 1.

In a 100 mL three-necked round bottom flask equipped with a nitrogen inlet, mechanical stirrer, and cold water bath, 0.36 mmol of target monomer, 5.64 mmol of ODA, and under conditions of sufficient water and oxygen removal and nitrogen protection. 10 ml of DMAc was added and stirred until it dissolved and formed a homogeneous solution; a total of 6 mmol of PMDA was added to the above solution three times and stirred for 14 hours in a cold water bath to react and then reach a certain viscosity. A black polyamic acid solution was obtained.

After defoaming, the polyamic acid solution was uniformly applied onto a dry, clean glass plate using an automatic film coating machine, and an imidization reaction was performed using a thermal imidization method. The temperature curing procedure was as follows: 80°C/3 hours, 100°C/1 hour, 200°C/2 hours, 300°C/4 hours.
Example 4
This example relates to the synthesis of true black polyimide PI-2.

1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, ODA (4,4'-diaminodiphenyl ether), and PMDA (pyromellitic dianhydride) in a molar ratio of 6:94. A black polyimide film was prepared using the same method as described above, and the solids content was 15.3%. The ratio of the total number of moles of amine groups involved in the reaction of the anthraquinone derivative tetraamine monomer and the diamine monomer to the total number of moles of carboxylic acid anhydride groups involved in the reaction of the acid anhydride monomer is 1: It was 1.

In a 100 mL three-necked round bottom flask equipped with a nitrogen inlet, mechanical stirrer, and cold water bath, 0.36 mmol of target monomer, 5.64 mmol of ODA, and under conditions of sufficient water and oxygen removal and nitrogen protection. 10 ml of DMAc was added and stirred until it dissolved and formed a homogeneous solution; a total of 6 mmol of PMDA was added to the above solution three times and stirred for 14 hours in a cold water bath to react and then reach a certain viscosity. A black polyamic acid solution was obtained.

After defoaming, the polyamic acid solution was uniformly applied onto a dry, clean glass plate using an automatic film coating machine, and an imidization reaction was performed using a thermal imidization method. The temperature curing procedure was as follows: 80°C/3 hours, 100°C/1 hour, 200°C/2 hours, 300°C/4 hours.
Example 5
This example relates to the synthesis of true black polyimide PI-3.

1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, ODA (4,4'-diaminodiphenyl ether), and PMDA (pyromellitic dianhydride) in a molar ratio of 8:92. A black polyimide film was prepared using the same method as described above, and the solids content was 15.3%. The ratio of the total number of moles of amine groups involved in the reaction of the anthraquinone derivative tetraamine monomer and the diamine monomer to the total number of moles of carboxylic acid anhydride groups involved in the reaction of the acid anhydride monomer is 1: It was 1.

In a 100 mL three-necked round bottom flask equipped with a nitrogen inlet, mechanical stirrer, and cold water bath, 0.36 mmol of target monomer, 5.64 mmol of ODA, and under conditions of sufficient water and oxygen removal and nitrogen protection. 10 ml of DMAc was added and stirred until it dissolved and formed a homogeneous solution; a total of 6 mmol of PMDA was added to the above solution three times and stirred for 14 hours in a cold water bath to react and then reach a certain viscosity. A black polyamic acid solution was obtained.

After defoaming, the polyamic acid solution was uniformly applied onto a dry, clean glass plate using an automatic film coating machine, and an imidization reaction was performed using a thermal imidization method. The temperature curing procedure was as follows: 80°C/3 hours, 100°C/1 hour, 200°C/2 hours, 300°C/4 hours.
Example 6
This example relates to the synthesis of true black polyimide PI-4.

1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, ODA (4,4'-diaminodiphenyl ether), and PMDA (pyromellitic dianhydride) in a molar ratio of 10:90. A black polyimide film was prepared using the same method as described above, and the solids content was 15.3%. The ratio of the total number of moles of amine groups involved in the reaction of the anthraquinone derivative tetraamine monomer and the diamine monomer to the total number of moles of carboxylic acid anhydride groups involved in the reaction of the acid anhydride monomer is 1: It was 1.

In a 100 mL three-necked round bottom flask equipped with a nitrogen inlet, mechanical stirrer, and cold water bath, 0.36 mmol of target monomer, 5.64 mmol of ODA, and under conditions of sufficient water and oxygen removal and nitrogen protection. 10 ml of DMAc was added and stirred until it dissolved and formed a homogeneous solution; a total of 6 mmol of PMDA was added to the above solution three times and stirred for 14 hours in a cold water bath to react and then reach a certain viscosity. A black polyamic acid solution was obtained.

After defoaming, the polyamic acid solution was uniformly applied onto a dry, clean glass plate using an automatic film coating machine, and an imidization reaction was performed using a thermal imidization method. The temperature curing procedure was as follows: 80°C/3 hours, 100°C/1 hour, 200°C/2 hours, 300°C/4 hours.
Example 7

1,8-dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone, ODA (4,4'-diaminodiphenyl ether), and PMDA (pyromellitic dianhydride) in a molar ratio of 80:20. A black polyimide film was prepared using the same method as described above, and the solids content was 15.3%. The ratio of the total number of moles of amine groups involved in the reaction of the tetraamine monomer and the diamine monomer to the total number of moles of carboxylic acid anhydride groups involved in the reaction of the acid anhydride monomer is 1:1. there were.

In a 100 mL three-necked round bottom flask equipped with a nitrogen inlet, mechanical stirrer, and cold water bath, 0.36 mmol of target monomer, 5.64 mmol of ODA, and under conditions of sufficient water and oxygen removal and nitrogen protection. 10 ml of DMAc was added and stirred until it dissolved and formed a homogeneous solution; a total of 6 mmol of PMDA was added to the above solution three times and stirred for 14 hours in a cold water bath to react and then reach a certain viscosity. A black polyamic acid solution was obtained.

After defoaming, the polyamic acid solution was uniformly applied onto a dry, clean glass plate using an automatic film coating machine, and an imidization reaction was performed using a thermal imidization method. The temperature curing procedure was as follows: 80°C/3 hours, 100°C/1 hour, 200°C/2 hours, 300°C/4 hours.

Compared to the true black polyimide of Example 6, the true black polyimide of Example 7 has lower optical properties, increased elastic modulus, lower elongation at break and lower tensile strength, and almost no change in dielectric properties. There wasn't.
Comparative example 1
This example relates to the synthesis of a PMDA-ODA type PI film.

A Kapton type polyimide film was prepared using ODA (4,4'-diaminodiphenyl ether) and PMDA (pyromellitic dianhydride) in a molar ratio of 1:1, and the solid content was 15.1%. The ratio of the total number of moles of amine groups in the diamine monomer to the total number of moles of carboxylic acid anhydride groups in the acid anhydride monomer was 1:1.

In a 100 mL three-necked round bottom flask equipped with a nitrogen inlet, mechanical stirrer, and cold water bath, under conditions of sufficient water and oxygen removal and nitrogen protection, add 6 mmol ODA and 10 ml DMAc, dissolve and homogenize. A total of 6 mmol of PMDA was added to the above solution three times and stirred in a cold water bath for 14 hours to form a solution; after reacting, a pale yellow polyamic acid solution with a specific viscosity was obtained. Ta.

After defoaming, the polyamic acid solution was uniformly applied onto a dry, clean glass plate using an automatic film coating machine, and an imidization reaction was performed using a thermal imidization method. The temperature curing procedure was as follows: 80°C/3 hours, 100°C/1 hour, 200°C/2 hours, 300°C/4 hours.
Comparative example 2
Comparative Example 2 is a bright surface doped black film, item number BY112, purchased from Ningbo Imashan.
Comparative example 3
Comparative Example 3 is a matte doped black film, part number BY112, purchased from Ningbo Imasan.
Characteristic evaluation

The ultraviolet absorption spectra, LAB values, dielectric properties, thermal properties, and mechanical properties of the polyimides according to Example 3-6 and Comparative Example 1-3 were measured, and the test results are shown in Table 1-4 below.

Table 1 Transmittance T ₆₀₀ (%) and LAB value at 600 nm of polyimide of Example 3-6 and Comparative Example 1-3.

Table 2 Thermal property data and mechanical property data of polyimide of Example 3-6 and Comparative Example 1-3

Table 3 Mechanical property data of polyimide of Example 3-6 and Comparative Example 1-3

Table 4 Dielectric property data of polyimide of Example 3-6 and Comparative Example 1-3

From the above data, when the anthraquinone derivative tetraamine monomers described in this disclosure account for more than 4% of the moles of the total amine monomers, the prepared black polyimide has good light-shielding performance and excellent mechanical properties. It can be seen that it has good properties, thermal stability, and dielectric properties, and has a light transmittance of less than 1% in all wavelength bands.

The above description of the embodiments is disclosed to enable any person skilled in the art to easily understand and apply the present application. It will be obvious to those skilled in the art that various modifications can be readily made to these embodiments and that the general principles described herein can be applied to other embodiments without creative effort. . Accordingly, this application is not limited to the examples herein, and those skilled in the art will appreciate that improvements and changes can be made based on the content disclosed in this application without departing from the scope and spirit of this application. , within the scope of this application.

Claims (10)

An anthraquinone derivative tetraamine monomer characterized by having a structure represented by the following general formula I.
2. A method for preparing an anthraquinone derivative tetraamine monomer according to claim 1, wherein the method comprises converting 1,8-dihydroxy-9,10-anthraquinone to 1,8-dihydroxy in the presence of concentrated sulfuric acid and concentrated nitric acid. -2,4,5,7-tetranitro-9,10-anthraquinone, followed by reduction of the nitro group to the amino group to give 1,8-dihydroxy-2,4,5,7-tetraamino-9, A method for preparing an anthraquinone derivative tetraamine monomer, characterized in that it comprises obtaining 10-anthraquinone. 2. A method for preparing an anthraquinone derivative tetraamine monomer according to claim 1, the method comprising: 1,8-dihydroxy-4 in the presence of concentrated sulfuric acid and concentrated nitric acid; ,5-dinitro-9,10-anthraquinone to 1,8-dihydroxy-2,4,5,7-tetranitro-9,10-anthraquinone, followed by reduction of the nitro group to the amino group, A method for preparing an anthraquinone derivative tetraamine monomer, comprising obtaining -dihydroxy-2,4,5,7-tetraamino-9,10-anthraquinone. A true black polyimide comprising a structural unit derived from an anthraquinone derivative tetraamine monomer, a structural unit derived from a diamine monomer, and a structural unit derived from an acid anhydride monomer according to claim 1, wherein the anthraquinone derivative tetra A true black polyimide, wherein the structural unit derived from the amine monomer accounts for 4% or more of the total number of moles of the structural unit derived from the anthraquinone derivative tetraamine monomer and the structural unit derived from the diamine monomer. The structural unit derived from the anthraquinone derivative tetraamine monomer accounts for 4% to 10% of the total number of moles of the structural unit derived from the anthraquinone derivative tetraamine monomer and the structural unit derived from the diamine monomer. The true black polyimide according to claim 4. The ratio of the total number of moles of amine groups involved in the reaction of the anthraquinone derivative tetraamine monomer and the diamine monomer to the total number of moles of carboxylic acid anhydride groups involved in the reaction of the acid anhydride monomer is 1:1. The true black polyimide according to claim 4, characterized in that: The acid anhydride monomers include 4,4'-(acetylene-1,2-diyl)diphthalic anhydride, pyromellitic dianhydride, and 3,3',4,4'-biphenyltetracarboxylic dianhydride. , 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2'-bis(3,4-dicarboxylic acid) hexafluoropropane dianhydride, 4,4'-oxydiphthalic anhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic acid The true black polyimide according to claim 4, characterized in that it is one or more of dianhydride and diphenyl sulfide dianhydride. The diamine monomers include m-phenylenediamine, p-phenylenediamine, 4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, and 4,4'-diaminodiphenyl ether. '-Diamino diphenylmethane, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-diamino-2,2'-dimethylbiphenyl, 2-(4 -aminophenyl)-5-aminobenzoxazole, 2-(4-aminophenyl)-5-aminobenzimidazole, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis(3-hydroxy-4 -aminophenoxy)benzene, 2-(4-aminophenyl)-6-aminobenzoxazole, 2,2-p-phenyl-bis(5-aminobenzoxazole) and 2,2'-p-phenyl-bis(6 -aminobenzoxazole) according to claim 4. 5. A method of preparing a true black polyimide according to claim 4, the method comprising the following steps:
(1) Under anhydrous and oxygen-free conditions, mix the anthraquinone derivative tetraamine monomer and diamine monomer according to claim 1 in a predetermined weight ratio, stir until dissolved to form a homogeneous solution, and then After adding the anhydride monomer and stirring and reacting for a given time in a cold water bath, a black polyamic acid solution is obtained;
(2) Imidizing a black polyamic acid solution to obtain a true black polyimide;
A method for preparing a true black polyimide, characterized by the following. For imidization of the black polyamic acid solution, after defoaming, the black polyamic acid solution was uniformly applied onto a dry, clean glass plate using an automatic film coating machine, and the temperature curing procedure was performed at 80°C/3. The preparation according to claim 9, characterized in that the imidization reaction is carried out by a thermal imidization method such that the time is 100°C/1 hour, 200°C/2 hours, 300°C/4 hours. Method.