A tetraphenyldiamine monomer containing trifluoromethyl groups, its preparation method and applications

Abstract

This invention discloses a tetraphenyldiamine monomer containing trifluoromethyl groups, its preparation method, and its application. The structural formula of the tetraphenyldiamine monomer containing trifluoromethyl groups is shown in formula (1). It can be used as a raw material to prepare polyimide materials. The preparation method includes the following steps: (1) dissolving the raw material in organic solvent A, adding an alkaline solution and Aliquat 336 to obtain a mixed solution; (2) adding catalyst A to the mixed solution, heating and reacting under a protective atmosphere, and obtaining an intermediate product after purification; (3) adding organic solvent B and catalyst B to the intermediate product, heating and reacting under a hydrogen atmosphere, and then post-processing. The raw materials used in this invention are all readily available commercial products. The synthetic route is simple, the product purity and yield are high, and it is stable at room temperature. The polyimide material obtained by using the diamine monomer of this invention has excellent dielectric properties, high optical transparency, good thermal stability, and mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and more particularly to a tetraphenyldiamine monomer containing trifluoromethyl groups, its preparation method, and its applications. Background Technology

[0002] Polyimide, as a typical high-performance polymer material, possesses excellent thermal stability, mechanical strength, chemical stability, and electrical insulation. Furthermore, its flexibility meets the requirements of current flexible wearable devices, leading to its wide application in the microelectronics industry. However, the dielectric constant of traditional polyimide materials is typically above 3.0, which limits their further application in fields such as ultra-large-scale integration, high-frequency and high-speed transmission, and micro-components. In addition, due to the formation of intramolecular and intermolecular charge-transfer complexes (CTCs), polyimides generally have a darker color, making it difficult to meet the requirements of display technology. Therefore, designing and researching high-performance, low-dielectric, and highly transparent polyimide materials is of great significance.

[0003] The reduction of the dielectric constant of polyimide is mainly achieved through two main approaches: First, by introducing pores to reduce material density and polarizing component concentration. This is one of the most effective and widely used methods for reducing the dielectric constant of polyimide; however, the presence of pores can severely affect the thermal stability and mechanical properties of the material, increase its hygroscopicity, and lead to significant problems in subsequent processing and applications. Second, by structurally designing the monomers, low-polarizability and large-volume functional groups are introduced into the polyimide molecular chain, thereby obtaining intrinsically low-dielectric-constant polyimide materials. Through reasonable structural design, the inherent high heat resistance and other characteristics of polyimide materials can also be maintained or even improved, thus enabling them to meet the relatively high processing and application temperature requirements of the microelectronics industry.

[0004] The main methods to improve the transparency of polyimide are as follows: first, introducing strongly electronegative substituents such as trifluoromethyl; second, introducing alicyclic structures; and third, introducing large-volume or twisted rigid substituents. The goal of all these methods is to reduce or inhibit the formation of CTC.

[0005] Existing diamine monomers generally suffer from problems such as complex molecular structures, cumbersome preparation processes, and insufficient effectiveness in reducing dielectric constant. For example, Chen et al. reported a diamine monomer containing a large triphenylmethane side group (Reactive and Functional Polymers, 2016, 108, 71–77). The polyimide prepared by polymerizing it with 4,4'-(hexafluoroisopropene)phthalic anhydride has a low dielectric constant (2.33@10kHz) and good transparency (86% transmittance at 700nm for a 25μm thick film). It also exhibits good thermal stability and mechanical properties. However, this diamine monomer molecule suffers from the aforementioned problems of complex structure and cumbersome preparation process. Summary of the Invention

[0006] This invention provides a tetraphenyldiamine monomer containing trifluoromethyl groups, its preparation method, and its application, in order to solve the technical problems of existing diamine monomers having poor performance improvement effects on subsequent polyimide materials, complex structures, and cumbersome preparation processes.

[0007] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0008] A tetraphenyldiamine monomer containing trifluoromethyl groups, wherein the structural formula of the tetraphenyldiamine monomer containing trifluoromethyl groups is shown in formula (1):

[0009]

[0010] The design concept of the above technical solution lies in the fact that the diamine monomer has been designed with a structure containing m-trifluoromethylphenyl groups at the meta positions of both amino groups, thus forming a tetraphenyl structure with a melting point of 241.1–241.5 °C and a white solid at room temperature. The diamine monomer can introduce trifluoromethyl groups and a rigid tetraphenyl structure into the polyimide molecular chain. The steric hindrance effect of these two groups effectively hinders the close packing of the polyimide molecular chain, increases the molar volume of repeating structural units, increases the inter-chain spacing and free volume, dilutes the concentration of polar molecules, and reduces intermolecular interactions. Simultaneously, the strong electronegativity of fluorine atoms results in a very low polarizability of the CF bond, thereby reducing the dielectric constant and improving the transparency of the polyimide. Furthermore, the introduction of the highly rigid tetraphenyl structure also helps to improve the mechanical strength and thermal properties of the polyimide material. Therefore, the polyimide material obtained from the diamine monomer of this invention has excellent dielectric properties, high optical transparency, and good thermal stability and mechanical properties, and has broad application prospects in fields such as microelectronics.

[0011] Based on the same technical concept, the present invention also provides a method for preparing the above-mentioned tetraphenyldiamine monomer containing trifluoromethyl, comprising the following steps:

[0012] (1) Dissolve 4,4'-dibromo-2,2'-dinitrobiphenyl and 3,5-bis(trifluoromethyl)phenylboronic acid in organic solvent A, and add alkaline solution and 10-30 drops of Aliquat 336 to obtain a mixed solution;

[0013] (2) Add catalyst A to the mixed solution and heat it to a set temperature under a protective atmosphere to carry out the reaction. After the reaction is complete, the intermediate product is obtained by purification. The intermediate product is a dinitro compound 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-2,2'-dinitro-1,1'-biphenyl.

[0014] (3) Add organic solvent B and catalyst B to the intermediate product, heat to a set temperature under a hydrogen atmosphere to carry out the reaction, and after the reaction is completed, the tetraphenyldiamine monomer containing trifluoromethyl is obtained by post-treatment.

[0015] This invention successfully prepared a tetraphenyldiamine monomer containing trifluoromethyl groups using 4,4'-dibromo-2,2'-dinitrobiphenyl and 3,5-bis(trifluoromethyl)phenylboronic acid as raw materials via Suzuki coupling reaction and hydrogenation reduction reaction. All raw materials used are readily available commercial products, the synthetic route is relatively simple, and the product exhibits high purity and yield, and is stable at room temperature. The specific synthetic route is shown below:

[0016]

[0017] As a further preferred embodiment of the above technical solution, the molar ratio of 4,4'-dibromo-2,2'-dinitrobiphenyl and 3,5-bis(trifluoromethyl)phenylboronic acid in step (1) is 1:(2-3).

[0018] As a further preferred embodiment of the above technical solution, the organic solvent A in step (1) is at least one of tetrahydrofuran and toluene, and the mass of organic solvent A is 5 to 15 times the total mass of 4,4'-dibromo-2,2'-dinitrobiphenyl and 3,5-bis(trifluoromethyl)phenylboronic acid.

[0019] As a further preferred embodiment of the above technical solution, the alkaline solution in step (1) is an aqueous solution of carbonate, wherein the carbonate includes at least one of potassium carbonate and sodium carbonate, and the mass of the carbonate is 1.5 to 3 times the mass of 3,5-bis(trifluoromethyl)phenylboronic acid.

[0020] As a further preferred embodiment of the above technical solution, the catalyst A in step (2) is tetra(triphenylphosphine)palladium, and the amount of the catalyst A is 1% to 5% of the amount of 4,4'-dibromo-2,2'-dinitrobiphenyl.

[0021] As a further preferred embodiment of the above technical solution, the heating temperature in step (2) is 70-90°C and the reaction time is 24-48h.

[0022] As a further preferred embodiment of the above technical solution, the purification process in step (2) includes sequential liquid-liquid separation, washing, chromatographic separation and recrystallization operations.

[0023] As a further preferred embodiment of the above technical solution, the catalyst B in step (3) is 5% or 10% Pd / C, and the mass of the catalyst B is 2% to 10% of the mass of the intermediate product.

[0024] As a further preferred embodiment of the above technical solution, the organic solvent B in step (3) includes at least one of ethanol and tetrahydrofuran, and the mass of organic solvent B is 3 to 5 times the mass of the intermediate product.

[0025] As a further preferred embodiment of the above technical solution, the heating temperature in step (3) is 40-60°C and the reaction time is 24-48h.

[0026] As a further preferred embodiment of the above technical solution, the post-processing in step (3) includes sequential cooling, depressurization, filtration, drying and recrystallization operations.

[0027] Based on the same technical concept, the present invention also provides an application of the above-mentioned tetraphenyldiamine monomer containing trifluoromethyl or the tetraphenyldiamine monomer containing trifluoromethyl prepared by the above-mentioned preparation method, wherein the tetraphenyldiamine monomer containing trifluoromethyl is used as a raw material to prepare polyimide materials.

[0028] As a further preferred embodiment of the above technical solution, the preparation of polyimide materials using the tetraphenyldiamine monomer containing trifluoromethyl groups as a raw material includes the following steps:

[0029] Under inert gas protection, the monomers containing trifluoromethyltetraphenyldiamine, alicyclic diamine, and aromatic dianhydride monomer are added to a phenolic solvent, followed by the addition of quinoline or isoquinoline. The reaction is stirred at room temperature to 100°C to obtain a transparent, viscous polyamic acid solution. The temperature is then increased to 120–150°C for 5–12 hours, and then to 180–220°C for 12–24 hours. After the reaction is complete and cooled to room temperature, the product is precipitated, filtered, washed, and dried to obtain a polyimide polymer. The polyimide is then formulated into a solution and coated by spin-coating, blade coating, or casting to form a film. After drying, a low-dielectric, highly transparent polyimide film material is obtained. The specific synthesis route is shown below:

[0030]

[0031] As a further preferred embodiment of the above technical solution, the alicyclic diamine is one of commercially available alicyclic diamines such as 1,4-cyclohexanediamine and 4,4'-methylenedicyclohexaneamine, and its dosage is 1 / 5 to 1 / 2 of the total amount of diamine monomers; the aromatic dianhydride is one of commercially available aromatic dianhydrides such as 4,4'-(hexafluoroisopropene)phthalic anhydride, 4,4'-oxophthalic anhydride, and 3,3',4,4'-benzophenone tetracarboxylic dianhydride, and the molar ratio of the aromatic dianhydride monomer to the total amount of diamine monomer is (0.95 to 1.05):1; the solid content of the polyamic acid solution is 5 wt% to 30 wt%.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) The trifluoromethyl tetraphenyl diamine monomer prepared by this invention can be further used to prepare high-performance polyimide materials. By introducing trifluoromethyl groups and rigid tetraphenyl structures into the polyimide molecular chain through this diamine monomer, they have great steric hindrance, which can effectively hinder the movement and close packing of molecular chains, increase the molecular chain spacing and free volume, and at the same time, the strong electronegativity of fluorine atoms leads to very low polarizability of CF bonds. The combined effect of these two factors increases the molar volume of the prepared polyimide, reduces the molar polarizability, and effectively suppresses CTC, thereby achieving the purpose of reducing the dielectric constant and improving transparency. Moreover, the introduction of highly rigid tetraphenyl structures into the molecular chain is also beneficial to improving the thermal and mechanical properties of polyimide materials. Therefore, the polyimide materials prepared with the diamine monomer of this invention have excellent dielectric properties and high optical transparency, as well as good thermal stability and mechanical properties, and have broad application prospects in the microelectronics industry and other fields.

[0034] (2) The raw materials used in the preparation of the trifluoromethyl tetraphenyldiamine monomer of the present invention are all readily available commercial products, the synthetic route is relatively simple, the product has high purity and yield, and is stable at room temperature.

[0035] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0036] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0037] Figure 1 The intermediate product 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-2,2'-dinitro-1,1'-biphenyl of Example 1 1 H-NMR spectrum;

[0038] Figure 2The mass spectrum of 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine from Example 1 is shown.

[0039] Figure 3 The 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine of Example 1 1 H-NMR spectrum;

[0040] Figure 4 The 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine of Example 1 13 C-NMR spectrum. Detailed Implementation

[0041] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0042] Example 1:

[0043] The tetraphenyldiamine monomer 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine containing trifluoromethyl in this embodiment has the structural formula shown in formula (1):

[0044]

[0045] The method for preparing the trifluoromethyl-containing tetraphenyldiamine monomer in this embodiment includes the following steps:

[0046] (1) In a 2000 mL three-necked flask equipped with a spherical condenser and a magnetic stirrer, 20.10 g (0.05 mol) of 4,4'-dibromo-2,2'-dinitrobiphenyl and 32.24 g (0.125 mol) of 3,5-bis(trifluoromethyl)phenylboronic acid were dissolved in 588 mL of tetrahydrofuran. Then, 228 mL of a 2 mol / L sodium carbonate aqueous solution and 20 drops of Aliquat were added. 336. The mixture was stirred at room temperature for 45 min under nitrogen protection to remove air from the reaction flask. Then, 0.58 g (0.5 mmol) of tetra(triphenylphosphine)palladium catalyst was added, and the temperature was raised to 80 °C for 24 h. After cooling to room temperature, the aqueous phase was removed by liquid-liquid separation, washed with water, separated by chromatography, and then further recrystallized in toluene to give 25.07 g of the intermediate dinitro compound 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-2,2'-dinitro-1,1'-biphenyl, with a yield of 75%. 1 H-NMR (Acetone-d6, 500MHz) such as Figure 1As shown, δ8.77 (d, J=1.9Hz, 2H), 8.58 (s, 4H), 8.40 (dd, J=8.0, 2.0Hz, 2H), 8.18 (s, 2H), 7.76 (d, J=8.0Hz, 2H).

[0047] (2) 20.05 g (0.03 mol) of purified intermediate dinitro compound 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-2,2'-dinitro-1,1'-biphenyl and 90 mL of tetrahydrofuran were added to a dry reaction vessel. Then, 0.40 g of 10% Pd / C catalyst was added, and the mixture was purged with hydrogen and magnetically stirred at 45 °C for 48 h. After cooling and depressurization, the reaction solution was filtered to remove the catalyst. The filtrate was then dried to remove the solvent and recrystallized from toluene and ethanol to obtain 14.05 g of white solid, which was 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine, with a yield of 77%. Mass spectrometry is shown below. Figure 2 As shown, [M+H] + Theoretical value C 28 H 17 F 12 N2 + Measured value: 609.1195; Actual value: 609.1199; 1 H-NMR (DMSO-d6, 500MHz) Figure 3 As shown, δ8.24(s, 4H), 8.09(s, 2H), 7.28(s, 2H), 7.16(s, 4H), 4.93(s, 4H); 13 C-NMR (DMSO-d6, 126MHz) Figure 4 As shown, δ146.17, 143.12, 136.89, 131.62, 130.90 (q, J = 32.8 Hz), 126.84, 124.21, 123.39 (q, J = 273.4 Hz), 120.65, 115.66, 113.67.

[0048] Example 2:

[0049] The tetraphenyldiamine monomer 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine containing trifluoromethyl in this embodiment has the structural formula shown in formula (1):

[0050]

[0051] The method for preparing the trifluoromethyl-containing tetraphenyldiamine monomer in this embodiment includes the following steps:

[0052] (1) In a 2000 mL three-necked flask equipped with a spherical condenser and a magnetic stirrer, 20.10 g (0.05 mol) of 4,4'-dibromo-2,2'-dinitrobiphenyl and 25.79 g (0.10 mol) of 3,5-bis(trifluoromethyl)phenylboronic acid were dissolved in 567 mL of tetrahydrofuran. Then, 140 mL of a 2 mol / L potassium carbonate aqueous solution and 20 drops of Aliquat were added. 336. The mixture was stirred at room temperature for 40 min under nitrogen protection to remove air from the reaction flask. Then, 0.58 g (0.5 mmol) of tetra(triphenylphosphine)palladium catalyst was added, and the temperature was raised to 75 °C for 36 h. After cooling to room temperature, the aqueous phase was removed by liquid-liquid separation, washed with water, separated by chromatography, and then further recrystallized in toluene to give 26.40 g of the intermediate dinitro compound 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-2,2'-dinitro-1,1'-biphenyl, with a yield of 79%.

[0053] (2) 20.05 g (0.03 mol) of purified intermediate dinitro compound 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-2,2'-dinitro-1,1'-biphenyl and 90 mL of tetrahydrofuran were added to a dry reaction vessel. Then, 0.80 g of 5% Pd / C catalyst was added, and hydrogen was introduced. The reaction was magnetically stirred at 55 °C for 48 h. After cooling and depressurization, the reaction solution was filtered to remove the catalyst. The filtrate was then dried to remove the solvent and recrystallized from toluene and ethanol to obtain 14.78 g of white solid, which was 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine, with a yield of 81%.

[0054] Example 3:

[0055] The tetraphenyldiamine monomer 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine containing trifluoromethyl in this embodiment has the structural formula shown in formula (1):

[0056]

[0057] The method for preparing the trifluoromethyl-containing tetraphenyldiamine monomer in this embodiment includes the following steps:

[0058] (1) In a 2000 mL three-necked flask equipped with a spherical condenser and a magnetic stirrer, 20.10 g (0.05 mol) of 4,4'-dibromo-2,2'-dinitrobiphenyl and 38.69 g (0.15 mol) of 3,5-bis(trifluoromethyl)phenylboronic acid were dissolved in 661 mL of tetrahydrofuran. Then, 168 mL of a 2.5 mol / L potassium carbonate aqueous solution and 25 drops of Aliquat were added. 336. The mixture was stirred at room temperature for 45 min under nitrogen protection to remove air from the reaction flask. Then, 0.64 g (0.55 mmol) of tetra(triphenylphosphine)palladium catalyst was added, and the temperature was raised to 90 °C for 24 h. After cooling to room temperature, the aqueous phase was removed by liquid-liquid separation, washed with water, separated by chromatography, and then further recrystallized in toluene to give 26.74 g of the intermediate dinitro compound 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-2,2'-dinitro-1,1'-biphenyl, with a yield of 80%.

[0059] (2) 20.05 g (0.03 mol) of purified intermediate dinitro compound 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-2,2'-dinitro-1,1'-biphenyl and 76 mL of ethanol were added to a dry reaction vessel. Then, 0.50 g of 10% Pd / C catalyst was added, and hydrogen was introduced. The reaction was magnetically stirred at 50 °C for 36 h. After cooling and depressurization, the reaction solution was filtered to remove the catalyst. The filtrate was then dried to remove the solvent and recrystallized from toluene and ethanol to obtain 14.97 g of white solid, which was 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine, with a yield of 82%.

[0060] Example 4:

[0061] This embodiment uses the tetraphenyldiamine monomer containing trifluoromethyl groups from Example 1, 2, or 3 as raw material to prepare a low-dielectric, highly transparent polyimide (named PI-1), including the following steps:

[0062] Under nitrogen protection, 1.4602 g (2.4 mmol) of 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine and 0.0685 g (0.6 mmol) of 1,4-cyclohexanediamine were added to a 50 mL three-necked flask, followed by the addition of 1.3327 g (3 mmol) of 4,4'-(hexafluoroisopropene)phthalic anhydride and 20 mL of m-cresol, and then 5 drops of isoquinoline were added dropwise. The mixture was stirred at 85 °C for 12 h to obtain a viscous polyurethane. The ammonium acid solution was heated to 120℃ and then to 150℃, and stirred for 5 hours each time. Finally, the temperature was raised to 180℃ and stirred for another 12 hours. After the reaction solution was cooled to room temperature, it was poured into methanol to precipitate the precipitate. The precipitate was then filtered, washed, and dried to obtain polyimide resin PI-1. A certain amount of PI-1 resin was dissolved in N,N-dimethylacetamide to prepare a solution. The solution was then coated or cast into a film according to the required thickness. The film was then vacuum dried at 80℃ and 170℃ for 12 hours to obtain the corresponding PI-1 film material.

[0063] Example 5:

[0064] This embodiment uses tetraphenyldiamine monomer containing trifluoromethyl groups from Example 1, 2, or 3 as raw material to prepare a low-dielectric, highly transparent polyimide (named PI-2), including the following steps:

[0065] Under nitrogen protection, 1.0952 g (1.8 mmol) of 4,4'-bis[3”,5”-bis(trifluoromethyl)phenyl]-1,1'-biphenyl-2,2'-diamine and 0.1370 g (1.2 mmol) of 1,4-cyclohexanediamine were added to a 50 mL three-necked flask, followed by the addition of 1.3327 g (3 mmol) of 4,4'-(hexafluoroisopropene)phthalic anhydride and 14 mL of m-cresol, and then 5 drops of isoquinoline were added dropwise. The mixture was stirred at 80 °C for 12 h to obtain a viscous poly… The ammonium acid solution was heated to 120℃ and then to 150℃, and stirred for 5 hours each time. Finally, the temperature was raised to 200℃ and stirred for another 12 hours. After the reaction solution was cooled to room temperature, it was poured into methanol to precipitate the precipitate. The precipitate was then filtered, washed, and dried to obtain polyimide resin PI-2. A certain amount of PI-2 resin was dissolved in N,N-dimethylacetamide to prepare a solution. The solution was then coated or cast into a film according to the required thickness. The film was then vacuum dried at 80℃ and 180℃ for 12 hours to obtain the corresponding PI-2 film material.

[0066] Comparative Example 1:

[0067] The polyimide in this comparative example (named PI-3) was prepared by the following steps:

[0068] Under nitrogen protection, 0.6311 g (3 mmol) of 4,4'-methylenedicyclohexylamine was added to a 50 mL three-necked flask, followed by 1.3327 g (3 mmol) of 4,4'-(hexafluoroisopropene)phthalic anhydride and 17 mL of m-cresol, and 5 drops of isoquinoline. The mixture was stirred at 80 °C for 12 h to obtain a viscous polyamic acid solution. The temperature was then raised to 120 °C and 150 °C for 5 h each time, and finally raised to 200 °C and stirred for another 12 h. After the reaction solution cooled to room temperature, it was poured into methanol to precipitate the precipitate. The precipitate was then filtered, washed, and dried to obtain polyimide resin PI-3. A certain amount of PI-3 resin was dissolved in chloroform to prepare a solution. The solution was then coated or cast into a film according to the required thickness. The film was then vacuum dried at 60 °C and 100 °C for 12 h to obtain the corresponding PI-3 film material.

[0069] The polyimides PI-1 and PI-2 prepared in the above examples and the polyimide PI-3 prepared in the comparative example were subjected to performance tests. The results are shown in Tables 1-3. The dielectric properties are shown in Table 1, the optical and thermal properties are shown in Table 2, and the mechanical properties are shown in Table 3.

[0070] Table 1 Dielectric properties of polyimide

[0071]

[0072] Table 2 Optical and thermal properties of polyimide

[0073] polyimide Film thickness (μm) <![CDATA[T vis ① (%)]]> <![CDATA[T g ② (℃)]]> <![CDATA[T 5wt％ ③ (℃)]]> PI-1 25 93 328 537 PI-2 25 92 316 525 PI-3 25 90 266 499

[0074] Note: ① Average transmittance of visible light (400-760nm).

[0075] ② Glass transition temperature.

[0076] ③5% thermal weight loss temperature (nitrogen atmosphere).

[0077] Table 3 Mechanical properties of polyimide

[0078]

[0079] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and modifications obtained without departing from the technical concept of the present invention should also be considered within the protection scope of the present invention.

Claims

1. A trifluoromethyl-containing quaterphenyl diamine monomer characterized in that, The structural formula of the tetraphenyldiamine monomer containing trifluoromethyl is shown in formula (1): 。 2. A process for the preparation of trifluoromethyl-containing quaterphenyl diamine monomers according to claim 1, characterized in that, Includes the following steps: (1) Dissolve 4,4'-dibromo-2,2'-dinitrobiphenyl and 3,5-bis(trifluoromethyl)phenylboronic acid in organic solvent A, and add alkaline solution and 10~30 drops of Aliquat 336 to obtain a mixed solution; (2) Add catalyst A to the mixed solution, heat to a set temperature under a protective atmosphere to carry out the reaction, and after the reaction is complete, purify to obtain the intermediate product; (3) Add organic solvent B and catalyst B to the intermediate product, heat to a set temperature under hydrogen atmosphere to carry out the reaction, and after the reaction is completed, the tetraphenyldiamine monomer containing trifluoromethyl is obtained by post-treatment.

3. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, In step (1), the molar ratio of 4,4'-dibromo-2,2'-dinitrobiphenyl and 3,5-bis(trifluoromethyl)phenylboronic acid is 1:(2~3).

4. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, The organic solvent A mentioned in step (1) is one of tetrahydrofuran and toluene, and the mass of organic solvent A is 5 to 15 times the total mass of 4,4'-dibromo-2,2'-dinitrobiphenyl and 3,5-bis(trifluoromethyl)phenylboronic acid.

5. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, The basic solution in step (1) is an aqueous solution of a carbonate salt, including at least one of potassium carbonate and sodium carbonate, the mass of the carbonate salt being 3, 5 1.5 to 3 times the mass of bis(trifluoromethyl)phenylboronic acid.

6. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, The catalyst A mentioned in step (2) is tetra(triphenylphosphine)palladium, and the amount of catalyst A is 1% to 5% of the amount of 4,4'-dibromo-2,2'-dinitrobiphenyl.

7. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, The heating temperature in step (2) is 70~90℃ and the reaction time is 24~48h.

8. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, The purification process described in step (2) includes sequential liquid-liquid separation, washing, chromatographic separation and recrystallization.

9. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, The catalyst B mentioned in step (3) is 5% or 10% Pd / C, and the mass of the catalyst B is 2% to 10% of the mass of the intermediate product.

10. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, The organic solvent B mentioned in step (3) includes at least one of ethanol and tetrahydrofuran, and the mass of organic solvent B is 3 to 5 times the mass of the intermediate product.

11. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, The heating temperature in step (3) is 40~60℃ and the reaction time is 24~48h.

12. The method for preparing the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 2, characterized in that, The post-processing described in step (3) includes sequential cooling, depressurization, filtration, drying and recrystallization operations.

13. The application of a tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 1 or a tetraphenyldiamine monomer containing trifluoromethyl groups prepared by the preparation method according to any one of claims 2-12, characterized in that, The tetraphenyldiamine monomer containing trifluoromethyl groups is used as a raw material to prepare polyimide materials.

14. The application of the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 13, characterized in that, The preparation of polyimide materials using the trifluoromethyl-containing tetraphenyldiamine monomer as a raw material includes the following steps: Under inert gas protection, the monomers containing trifluoromethyltetraphenyldiamine, alicyclic diamine, and aromatic dianhydride are added to a phenolic solvent, followed by the addition of quinoline or isoquinoline. The mixture is stirred at room temperature to 100°C to obtain a transparent, viscous polyamic acid solution. The temperature is then increased to 120-150°C for 5-12 hours, and then to 180-220°C for 12-24 hours. After the reaction is completed and cooled to room temperature, the polyimide polymer is obtained through precipitation, filtration, washing, and drying. The polyimide is then formulated into a solution and formed into a film by spin coating, blade coating, or casting. After drying, the polyimide film material is obtained.

15. The application of the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 14, characterized in that, The alicyclic diamine is one of 1,4-cyclohexanediamine and 4,4'-methylenedicyclohexaneamine, and the amount used is 1 / 5 to 1 / 2 of the total amount of the diamine monomer.

16. The application of the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 14, characterized in that, The aromatic dianhydride is one of 4,4'-(hexafluoroisopropene)phthalic anhydride, 4,4'-oxobisphthalic anhydride, and 3,3',4,4'-benzophenone tetracarboxylic dianhydride, and the molar ratio of the total amount of the aromatic dianhydride monomer to the total amount of the diamine monomer is (0.95~1.05):

1.

17. The application of the tetraphenyldiamine monomer containing trifluoromethyl groups according to claim 14, characterized in that, The solid content of the polyamic acid solution is 5wt%~30wt%.

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