A flexible antistatic high temperature resistant FDC special film and its preparation method

Abstract

The present invention relates to the field of FDC special film materials, and provides a flexible antistatic and high temperature resistant FDC special film and a preparation method thereof. The film is composed of a polyimide / graphene precursor solution, a surface modified Ti3C2T x Nanobelts, 3-aminopropyltriethoxysilane, 2,2'-dihydroxydiphenyl ether, 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt and diisononyl phthalate. x The nanoribbons were surface-modified with ionic liquids to enhance their dispersibility and interfacial compatibility within the polyimide matrix. Through a multi-step lamination, functionalization, and hot-press curing process, a composite film with excellent flexibility, stable conductivity, and high thermal stability was produced. This film is suitable for use in flexible electronics, heat-resistant insulation materials, and high-temperature antistatic applications, demonstrating its broad potential.

Description

Technical Field

[0001] The present invention relates to the field of FDC special film materials, and in particular to a flexible antistatic and high-temperature resistant FDC special film and a preparation method thereof. Background Art

[0002] Flexible functional materials are becoming a key enabling technology in cutting-edge fields such as aerospace, flexible displays, smart wearables, and high-frequency communication electronics. In particular, flexible electronic devices operating in high-temperature, high-electric-field, or high-friction environments place increasingly stringent performance demands on their constituent materials. On the one hand, the materials must possess excellent flexibility and mechanical toughness to adapt to complex curves, dynamic deformation, or repeated folding. On the other hand, they must also possess stable and durable electrical conductivity to dissipate static electricity, transmit signals, or provide electromagnetic shielding, thereby preventing the risk of device failure caused by static electricity accumulation. Furthermore, the materials must maintain structural integrity and electrical stability in high-temperature environments, possessing excellent thermal stability and resistance to thermal decomposition to ensure long-term reliable device operation. Therefore, the development of high-performance membrane materials that combine flexibility, anti-static properties, and high-temperature resistance will not only effectively improve the reliability, safety, and service life of end devices, but will also drive industries such as flexible electronics, precision instruments, and high-end manufacturing towards higher-performance and more adaptable application systems, possessing significant engineering value and industrial prospects.

[0003] Although significant progress has been made in the fields of flexible materials, antistatic coatings and high-temperature resistant polymers in recent years, the existing material system still has obvious shortcomings in meeting the triple performance of flexibility, antistatic and high-temperature resistance. For example, the Chinese patent with publication number CN105085956B discloses a method for preparing an antistatic polyimide shielding black film. Although it has good flexibility and initial conductivity, its conductive path is easily degraded by heat and fails in a high-temperature environment, and lacks thermal stability guarantee; another example is CN101827882B, which discloses a polyimide film with excellent thermal stability. It has strong thermal stability, but due to the excessive rigidity of the inorganic filler, the overall flexibility of the film material is insufficient, making it difficult to meet the deformation requirements of flexible electronics. In addition, a large number of current antistatic film products use metal coatings or carbon-based fillers to construct a conductive network, but they have poor dispersibility and low interface compatibility. They are very likely to interrupt the conductive channel under heat treatment or stress, resulting in large resistance fluctuations, unstable electrostatic dissipation performance and other problems. The root cause of these problems lies in the lack of multi-scale collaborative design of the material system, which fails to achieve an organic unity of flexible mechanical properties, electrical conductivity, and thermal stability at the molecular structure, interface regulation, and composite construction levels. Therefore, it is urgent to develop a new material system with breakthroughs in microstructure regulation, molecular-level composites, and collaborative optimization of processing technology to achieve a synergistic improvement in these three properties and meet the high-performance requirements of complex application environments. Summary of the Invention

[0004] (1) Technical problems solved

[0005] The purpose of the present invention is to provide a flexible antistatic and high temperature resistant FDC special film and a preparation method thereof, so as to solve the problem that the current FDC special film has insufficient flexibility, antistatic and high temperature resistance.

[0006] (2) Technical solution

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A flexible antistatic and high temperature resistant FDC special film, comprising the following raw materials in parts by weight: 70-85 parts of polyimide / graphene precursor solution, surface modified Ti3C2T x 3.0-7.0 parts of nanobelts, 0.5-1.0 parts of 3-aminopropyltriethoxysilane, 0.5-1.5 parts of 2,2'-dihydroxydiphenyl ether, 0.5-1.5 parts of 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt, and 1.0-3.0 parts of diisononyl phthalate.

[0009] The surface modified Ti3C2T x Nanobelts are Ti3C2T x The nanobelts were obtained by surface modification with 1-butyl-3-methylimidazolium tetrafluoroborate;

[0010] Furthermore, the preparation method of the polyimide / graphene precursor solution is as follows: 2.5 to 4.5 parts of reduced graphene oxide are added to 3 to 8 parts of N-methylpyrrolidone, and the reduced graphene oxide sheets are fully dispersed on a molecular scale by ultrasonic dispersion for 30 to 45 minutes to form a uniform and stable graphene dispersion; 9.0 to 11.0 parts of 4,4'-diaminodiphenyl ether are added to the above graphene dispersion, and the mixture is stirred at a stirring rate of 300 to 400 rpm under nitrogen protection. dissolve, and then cool the system to 0-5°C; slowly add 13.0-15.0 parts of 4,4'-diphenyl ether dianhydride in batches to the above-mentioned low-temperature solution, continuously protect with nitrogen during the reaction, maintain a stirring rate of 300-400 rpm, control the temperature of the reaction system at 0-5°C, and gradually add the time at 2.5-3.5h. After the dianhydride is completely dissolved, continue to react at a constant stirring rate for 5-7h to obtain a polyamic acid precursor solution containing graphene, that is, a polyimide / graphene precursor solution.

[0011] Furthermore, the preparation method of reduced graphene oxide is as follows: 9.0-12.0 parts of graphene oxide are dispersed in 80.0-100.0 parts of deionized water, stirred at a stirring rate of 400-600 rpm for 30-45 minutes, after forming a uniform dispersion, 2.0-4.0 parts of vitamin C reducing agent are slowly added, the pH value of the system is controlled to be between 4.0 and 6.0, and then heated at 80-95° C. for 90-120 minutes. During the reaction, stirring is continuously performed to ensure that the reduction reaction proceeds uniformly. After the reaction is completed, the resulting mixture is cooled to room temperature, centrifuged at 8000-10000 rpm for 10-15 minutes to collect the precipitate, discard the supernatant, and repeatedly washed with deionized water 3-5 times, each time using 80-120 mL of washing liquid, until the pH value of the washing liquid is stabilized between 6.5 and 7.5, and the resulting precipitate is dried under vacuum conditions of 0.05-0.08 MPa for 18-24 hours to obtain reduced graphene oxide.

[0012] The present invention adopts the design of polyimide / graphene precursor solution mainly for enhancing the comprehensive performance of flexible antistatic high temperature resistant special film. This design constructs a uniform and stable composite structure at the molecular scale by introducing reduced graphene oxide into the polyamic acid system, thereby achieving a synergistic improvement in mechanical flexibility, electrical properties and thermal stability. In the preparation process, N-methylpyrrolidone is first used as a dispersion medium, and the reduced graphene oxide sheets are fully peeled and evenly distributed by ultrasonic dispersion to ensure their effective participation and interfacial bonding in the subsequent polymerization reaction; then, under nitrogen protection, 4,4'-diaminodiphenyl ether and 4,4'-diphenyl ether dianhydride are introduced in sequence according to specific temperature and time conditions to form a polyamic acid main chain, and form good physical crosslinking and interfacial interaction with the graphene sheets, thereby constructing a composite precursor solution with a continuous phase structure. In this system, reduced graphene oxide effectively improves the antistatic ability of the material through its high specific surface area and excellent electronic conductivity. At the same time, its two-dimensional sheet structure also gives the composite system good flexibility and thermal stability; and the polyamic acid precursor can be converted into a polyimide skeleton during the subsequent heat treatment process, providing excellent high temperature resistance and mechanical strength. It is worth noting that the reduced graphene oxide used here is obtained by mild reduction of graphene oxide with vitamin C. This method not only ensures the integrity and dispersibility of the graphene sheets, but also avoids the structural damage and impurity introduction caused by strong reducing agents, thereby further improving the stability and reliability of the system. Through the synergistic effect of the above-mentioned components, the present invention realizes the organic fusion of high flexibility, high conductivity and high thermal stability functions, and provides a practical and process-controllable technical path for the preparation of flexible functional membranes with multi-performance integration.

[0013] Furthermore, the surface modified Ti3C2T x The preparation method of nanobelts is as follows: 1.0 to 1.5 parts of Ti3C2Tx The nanobelts were mixed with 2.0-3.0 parts of 1-butyl-3-methylimidazolium tetrafluoroborate in a proportion and then ball-milled in a planetary ball mill for 60-70 minutes. The obtained solid was added to 100-120 parts of a mixture of deionized water and anhydrous ethanol with a volume fraction of 2:1, and ultrasonically treated for 55-65 minutes at an ultrasonic power of 200-300 W. After treatment, the nanobelts were centrifuged at 12000-15000 rpm for 15-20 minutes, the supernatant was discarded, and the precipitate was retained. The obtained precipitate was also washed alternately with water and ethanol for 3-4 times and then freeze-dried at -40--50°C for 18-24 hours to finally obtain surface-modified Ti3C2T x Nanoribbons.

[0014] Furthermore, the Ti3C2T x The preparation method of the nanobelts is as follows: first, 10.0-15.0 parts of Ti3AlC2 powder are slowly added to 100.0 parts of hydrofluoric acid HF solution with a mass concentration of 35%-45%, and the reaction is continued for 22-26 hours at 40-45°C with a magnetic stirring rate of 200-300 rpm to achieve selective etching of the Al layer in Ti3AlC2 to generate Ti3C2T x After the reaction is completed, the mixture is centrifuged at 5000-6000 rpm for 10-15 min, the supernatant is discarded and the precipitate is retained, and washed with deionized water for 4-6 times, with each washing liquid amount of 80-120 mL, until the pH value of the washing liquid is stable between 6.5 and 7.5. The obtained Ti3C2T x The wet precipitate was freeze-dried for 18 to 24 hours to obtain Ti3C2T x powder, and then 2.0 to 3.0 parts of Ti3C2T x The powder was dispersed in 100.0 parts of potassium hydroxide (KOH) solution with a mass concentration of 5.5-6.5 mol / L, and stirred at 25-30 °C for 20-30 h under nitrogen protection. The stirring rate was controlled at 250-350 rpm. During the reaction, Ti3C2T x The sheets are gradually sheared and peeled along the interlayer direction in an alkaline solution to form a one-dimensional ribbon structure. After the reaction is completed, the system is centrifuged at 5000-6000 rpm for 10-15 minutes, the supernatant is discarded, and the precipitate is retained and washed with deionized water until the pH value is restored to 6.5-7.5. Finally, the obtained precipitate is dried under vacuum conditions of 0.05-0.08 MPa for 20-24 hours to obtain Ti3C2T x Nanoribbon powder.

[0015] Furthermore, the Ti3C2T x The average width of the nanoribbons is 50 to 150 nm; the average length is 1.5 to 3.5 μm;

[0016] Furthermore, the Ti3C2T x It is a two-dimensional carbide whose surface terminal groups are selected from fluorine (F), hydroxyl (OH) and oxygen (O).

[0017] The present invention adopts surface modified Ti3C2T x The design of nanobelts is mainly used to enhance the conductivity, thermal stability and interface synergy of flexible antistatic and high temperature resistant special films. This technical solution is based on the Ti3C2T x The structural regulation and surface modification of nanobelts have achieved uniform dispersion in the polymer matrix and significantly improved the functional synergy performance. x The nanobelts were prepared by using Ti3AlC2 as a precursor and selectively etching with a high concentration of hydrofluoric acid solution under controlled temperature and stirring rate conditions to effectively remove the Al layer and generate lamellar Ti3C2T x The high-purity two-dimensional carbide material was obtained after multiple washing and freeze-drying; it was then dispersed in potassium hydroxide solution and subjected to long-term alkaline shear exfoliation to make Ti3C2T x The sheets were transformed into a one-dimensional ribbon structure with a high aspect ratio along the interlayer direction, which significantly improved its distribution stability and network construction ability in the composite material. On this basis, the surface of the obtained nanobelts was functionalized using 1-butyl-3-methylimidazolium tetrafluoroborate, and the bonding between the ionic liquid and Ti3C2T was enhanced by combining ball milling and ultrasound. x The surface interaction allows the terminal groups on the surface to be regulated and form a coating with excellent interfacial activity, thereby improving the dispersion of the nanobelts in polar or weakly polar systems and the interfacial bonding ability with the polymer matrix. The final surface-modified Ti3C2T x Nanobelts have controllable size structure and surface chemical properties. They not only retain the excellent conductivity and thermal stability of two-dimensional carbides, but also effectively alleviate the agglomeration problem between fillers through the introduction of ionic liquids, thereby improving their networking ability and functional synergy in the composite system, thereby providing stable and long-lasting functional support for flexible anti-static and high-temperature resistant film materials, and realizing the organic unity of conductive channel construction, thermal stability maintenance and flexible structure regulation.

[0018] The present invention also discloses a method for preparing a flexible antistatic and high temperature resistant FDC special film, comprising the following steps:

[0019] S1. Mix the polyimide / graphene precursor solution with the surface-modified Ti3C2T x The nanoribbons are mixed to form a dispersion under mechanical stirring;

[0020] S2. The dispersion was heated and 3-aminopropyltriethoxysilane was added dropwise for functionalization;

[0021] S3. Add 2,2'-dihydroxydiphenyl ether, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and diisononyl phthalate and mix at a constant temperature;

[0022] S4. Filtration and degassing followed by coating and film formation;

[0023] S5. Gradual heating and hot pressing to solidify and cool to obtain the finished product.

[0024] Furthermore, the entire process of steps S1 to S5 is carried out under a nitrogen protective atmosphere;

[0025] In step S1, the stirring rate is 500-700 rpm, the stirring time is 40-60 min, and the ambient temperature is 25-30° C.;

[0026] In step S2, the mixed solution is heated to 80-90° C., the dropwise addition rate of 3-aminopropyltriethoxysilane is 0.1-0.3 mL / min, the stirring rate is 400-600 rpm, the reaction time is 60-90 min, and the reaction is carried out under nitrogen protection;

[0027] Furthermore, in step S3, the constant temperature stirring temperature is 80-90°C and the time is 30-45 minutes;

[0028] In step S4, the precursor solution is filtered through a 0.45 μm polytetrafluoroethylene filter membrane, the vacuum degassing pressure is -0.08 to -0.1 MPa, the degassing time is 20 to 30 min, the coating thickness is 50 to 80 μm, the scraping rate is 3 to 5 mm / s, the pre-drying temperature is 80 to 100° C., and the time is 30 to 60 min;

[0029] Furthermore, in step S5, the hot pressing heating rate is 3-5°C / min, the heat treatment temperature is 250-300°C, the holding time is 1.5-2.5h, the cooling rate is 1-2°C / min, and the whole process is carried out under a nitrogen atmosphere.

[0030] The present invention adopts a design combining multi-component collaborative construction with gradient hot pressing curing, which is mainly used to enhance the structural integrity, conductive stability and thermal environment adaptability of the flexible antistatic and high temperature resistant FDC special membrane. This technical solution ensures the effective dispersion, interfacial reaction and synergistic effect of each functional component in the composite system by scientifically arranging the process parameters of each step and the order of component introduction, thereby giving the final membrane multiple performance advantages. In the initial step, the polyimide / graphene precursor solution is mixed with the surface modified Ti3C2T x The nanobelts are fully mixed at a suitable temperature and stirring rate to effectively ensure the adhesion of graphene and Ti3C2T xThe uniform distribution at the molecular level provides a high-quality dispersion foundation for subsequent functional construction; 3-aminopropyltriethoxysilane is then added dropwise under heating conditions to introduce functional groups. Its surface reaction improves the compatibility of the inorganic / organic interface and forms stable chemical bonds at the interface, enhancing structural stability and interfacial energy transfer capabilities; on this basis, 2,2'-dihydroxydiphenyl ether is further introduced as a thermal stabilizer, synergistically with the ionic lubrication and conductive functions of 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt and the flexibility regulation effect of diisononyl phthalate, to form a uniform composite system under constant temperature blending conditions, thereby improving overall flexibility and resistance to thermal decomposition; after completing the component construction, filtration and degassing are performed to ensure that the membrane material is free of bubble defects, and then a gradient temperature increase hot pressing curing process is used under nitrogen protection to convert polyamic acid into polyimide while accompanies the stable construction of the network structure between components, ultimately forming a composite membrane with a dense structure, stable conductive channels and excellent heat resistance. The nitrogen atmosphere throughout the entire preparation process effectively prevents oxidation and degradation at high temperatures, ensuring film material stability. Precise control of parameters during the scraping, hot pressing, and cooling processes further enhances film quality and thickness uniformity. Synergistic efficiencies are achieved between the various components at multiple levels, including physical dispersion, chemical reaction, and interface regulation. The resulting FDC specialty film exhibits excellent flexibility, durable antistatic properties, and superior thermal stability, meeting the diverse demands of flexible electronics, thermal protection, and high-end packaging applications in demanding environments.

[0031] (3) Beneficial technical effects

[0032] 1. The present invention introduces vitamin C-reduced graphene oxide into a polyamic acid system to construct a uniform composite structure, thereby achieving synergistic improvements in flexibility, anti-static performance, and high-temperature resistance, solving the problems of unstable conductivity and easy pyrolysis of existing film materials, and is suitable for fields such as high-temperature flexible electronics.

[0033] 2. The present invention modifies Ti3C2T by surface x Nanobelts construct a stable conductive network to solve the problems of poor conductivity and low thermal stability of existing film materials. The core components synergistically improve interface bonding and dispersion, significantly enhancing the overall performance of the film material, making it suitable for high-temperature flexible electronics and other fields.

[0034] 3. The present invention achieves a dense film structure, stable conductive channels and optimized interface compatibility through multi-component synergy and gradient hot pressing curing, significantly improving flexibility, anti-static and high-temperature resistance, and solving the problems of rapid thermal decomposition and unstable conductivity in the existing technology. It is suitable for the field of high-end flexible electronics. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Ti3C2T prepared in Example 1 of the present invention x Nanoribbon morphology.

[0036] Figure 2 Ti3C2T prepared in Example 1 of the present invention x XRD phase analysis of nanobelts. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0038] Example 1

[0039] A flexible antistatic and high temperature resistant FDC special film, comprising the following raw materials in parts by weight: 70 parts of polyimide / graphene precursor solution, surface modified Ti3C2T x 3.0 parts of nanobelts, 0.5 parts of 3-aminopropyltriethoxysilane, 0.5 parts of 2,2'-dihydroxydiphenyl ether, 0.5 parts of 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt, and 1.0 parts of diisononyl phthalate.

[0040] The surface modified Ti3C2T x Nanobelts are Ti3C2T x The nanobelts were obtained by surface modification with 1-butyl-3-methylimidazolium tetrafluoroborate;

[0041] The preparation method of the polyimide / graphene precursor solution of this embodiment is as follows: 2.5 parts of reduced graphene oxide are added to 3 parts of N-methylpyrrolidone, and the reduced graphene oxide sheets are fully dispersed on the molecular scale by ultrasonic dispersion for 30 minutes to form a uniform and stable graphene dispersion; 9.0 parts of 4,4'-diaminodiphenyl ether are added to the above-mentioned graphene dispersion, and stirred and dissolved under nitrogen protection and a stirring rate of 300 rpm, and then the system is cooled to 0°C; 13.0 parts of 4,4'-diphenyl ether dianhydride are slowly added to the above-mentioned low-temperature solution in batches, and nitrogen protection is continued during the reaction, the stirring rate is maintained at 300 rpm, the reaction system temperature is controlled at 0°C, and the gradual addition time is controlled at 2.5 hours. After the dianhydride is completely dissolved, the reaction is continued at a constant stirring rate for 5 hours to obtain a graphene-containing polyamic acid precursor solution, that is, a polyimide / graphene precursor solution.

[0042] The preparation method of reduced graphene oxide in this embodiment is as follows: 9.0 parts of graphene oxide are dispersed in 80.0 parts of deionized water, stirred at a stirring rate of 400 rpm for 30 minutes, and after forming a uniform dispersion, 2.0 parts of vitamin C reducing agent are slowly added to control the pH value of the system to be between 4.0, and then heated at 80° C. for 90 minutes. During the reaction, stirring is continued to ensure that the reduction reaction proceeds uniformly. After the reaction is completed, the resulting mixture is cooled to room temperature and centrifuged at 8000 rpm for 10 minutes to collect the precipitate. The supernatant is discarded and the mixture is repeatedly washed three times with deionized water, each time using 80 mL of washing solution, until the pH value of the washing solution stabilizes between 6.5. The resulting precipitate is dried under vacuum conditions of 0.05 MPa for 18 hours to obtain reduced graphene oxide.

[0043] The surface modified Ti3C2T x The preparation method of nanobelts is as follows: 1.0 part of Ti3C2T x The nanobelts were mixed with 2.0 parts of 1-butyl-3-methylimidazolium tetrafluoroborate in a planetary ball mill for 60 minutes. The obtained solid was added to 100 parts of a mixture of deionized water and anhydrous ethanol with a volume fraction of 2:1 and ultrasonically treated for 55 minutes at an ultrasonic power of 200 W. After treatment, the mixture was centrifuged at 12000 rpm for 15 minutes, the supernatant was discarded, and the precipitate was also washed alternately with water and ethanol three times and freeze-dried at -40°C for 18 hours to obtain surface-modified Ti3C2T x Nanoribbons.

[0044] The Ti3C2T x The preparation method of the nanobelts is as follows: first, 10.0 parts of Ti3AlC2 powder are slowly added to 100.0 parts of 35% hydrofluoric acid HF solution, and the reaction is continued for 22 hours at 40°C with a magnetic stirring rate of 200 rpm to achieve selective etching of the Al layer in Ti3AlC2 to generate Ti3C2T x After the reaction, the mixture was centrifuged at 5000 rpm for 10 min, the supernatant was discarded and the precipitate was retained, and washed with deionized water for 4 times, each time with 80 mL of washing solution, until the pH value of the washing solution was stable between 6.5. The obtained Ti3C2T x Ti3C2T was obtained after the wet precipitate was freeze-dried for 18 h. x powder, and then 2.0 parts of Ti3C2T x The powder was dispersed in 100 parts of 5.5 mol / L potassium hydroxide (KOH) solution and stirred at 25 °C for 20 h under nitrogen protection. The stirring rate was controlled at 250 rpm. During the reaction, Ti3C2T xThe sheets were gradually sheared and peeled along the interlayer direction in the alkaline solution to form a one-dimensional ribbon structure. After the reaction was completed, the system was centrifuged at 5000 rpm for 10 min, the supernatant was discarded, and the precipitate was retained and washed with deionized water until the pH value returned to 6.5. Finally, the obtained precipitate was dried under 0.05 MPa vacuum for 20 h to obtain Ti3C2T x Nanoribbon powder.

[0045] The Ti3C2T x The average width of the nanoribbons is 50 nm; the average length is 1.5 μm; Ti3C2T x A two-dimensional carbide having a surface terminal group selected from fluorine (F), hydroxyl (OH) and oxygen (O);

[0046] The method for preparing a flexible antistatic and high temperature resistant FDC special film of this embodiment includes the following steps:

[0047] S1. Mix the polyimide / graphene precursor solution with the surface-modified Ti3C2T x The nanoribbons were mixed to form a dispersion under mechanical stirring at a stirring rate of 500 rpm, a stirring time of 40 min, and an ambient temperature of 25°C.

[0048] S2. The dispersion was heated and 3-aminopropyltriethoxysilane was added dropwise for functionalization; the mixture was heated to 80 ° C, the drop rate of 3-aminopropyltriethoxysilane was 0.1 mL / min, the stirring rate was 400 rpm, the reaction time was 60 min, and the reaction was carried out under nitrogen protection;

[0049] S3. Add 2,2'-dihydroxydiphenyl ether, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and diisononyl phthalate and mix at a constant temperature; stir at a constant temperature of 80 ° C for 30 min;

[0050] S4. After filtration and degassing, the film was coated; the precursor was filtered through a 0.45μm polytetrafluoroethylene filter membrane, the vacuum degassing pressure was -0.08MPa, the degassing time was 20min, the coating thickness was 50μm, the scraping rate was 3mm / s, the pre-drying temperature was 80℃, and the time was 30min;

[0051] S5. Gradient heating and hot pressing curing and cooling to obtain the finished product; the hot pressing heating rate is 3°C / min, the heat treatment temperature is 250°C, the holding time is 1.5h, and the cooling rate is 1°C / min. The whole process is carried out under a nitrogen atmosphere.

[0052] Figure 1 The Ti3C2T prepared in Example 1 of the present invention is shown. xThe morphological characteristics of the nanobelts can be observed from the figure. It presents a typical one-dimensional ribbon structure with a clear layered stacking morphology and a high aspect ratio. The edges are relatively clear, indicating that the material has been effectively exfoliated and a ribbon-shaped MXene structure has been successfully obtained from the precursor. Figure 2 The XRD phase analysis diagram of the nanobelt further verifies the sufficiency of the etching reaction and the Ti3C2T x Therefore, combined with the morphology and phase analysis results, it can be confirmed that the present invention has successfully prepared Ti3C2T with complete structure, extended interlayer spacing and good crystallinity by optimizing the etching and stripping process. x Nanoribbons.

[0053] Example 2

[0054] A flexible antistatic and high temperature resistant FDC special film, comprising the following raw materials in parts by weight: 75 parts of polyimide / graphene precursor solution, surface modified Ti3C2T x 4.2 parts of nanobelts, 0.7 parts of 3-aminopropyltriethoxysilane, 0.8 parts of 2,2'-dihydroxydiphenyl ether, 0.8 parts of 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt, and 1.6 parts of diisononyl phthalate.

[0055] The surface modified Ti3C2T x Nanobelts are Ti3C2T x The nanobelts were obtained by surface modification with 1-butyl-3-methylimidazolium tetrafluoroborate;

[0056] The preparation method of the polyimide / graphene precursor solution of this embodiment is as follows: 3.1 parts of reduced graphene oxide are added to 5 parts of N-methylpyrrolidone, and the reduced graphene oxide sheets are fully dispersed on the molecular scale by ultrasonic dispersion for 35 minutes to form a uniform and stable graphene dispersion; 9.6 parts of 4,4'-diaminodiphenyl ether are added to the above-mentioned graphene dispersion, and stirred and dissolved under nitrogen protection and a stirring rate of 330 rpm, and then the system is cooled to 2°C; 13.6 parts of 4,4'-diphenyl ether dianhydride are slowly added to the above-mentioned low-temperature solution in batches, and nitrogen protection is continued during the reaction process, the stirring rate is maintained at 330 rpm, the reaction system temperature is controlled at 2°C, and the gradual addition time is controlled at 2.8 hours. After the dianhydride is completely dissolved, the reaction is continued at a constant stirring rate for 6 hours to obtain a graphene-containing polyamic acid precursor solution, that is, a polyimide / graphene precursor solution.

[0057] The preparation method of reduced graphene oxide in this embodiment is as follows: 9.9 parts of graphene oxide are dispersed in 86.0 parts of deionized water, stirred at a stirring rate of 460 rpm for 35 minutes, and after forming a uniform dispersion, 2.6 parts of vitamin C reducing agent are slowly added to control the pH value of the system to be between 4.6, and then heated at 85° C. for 99 minutes. During the reaction, stirring is continued to ensure that the reduction reaction proceeds uniformly. After the reaction is completed, the resulting mixture is cooled to room temperature and centrifuged at 8600 rpm for 12 minutes to collect the precipitate. After discarding the supernatant, the mixture is repeatedly washed with deionized water four times, with an amount of 92 mL of washing solution used each time, until the pH value of the washing solution stabilizes between 6.8. The resulting precipitate is dried under vacuum conditions of 0.06 MPa for 20 hours to obtain reduced graphene oxide.

[0058] The surface modified Ti3C2T x The preparation method of nanobelts is as follows: 1.2 parts of Ti3C2T x The nanobelts were mixed with 2.3 parts of 1-butyl-3-methylimidazolium tetrafluoroborate in a planetary ball mill for 63 minutes. The obtained solid was added to 106 parts of a mixture of deionized water and anhydrous ethanol with a volume fraction of 2:1 and ultrasonically treated for 58 minutes at an ultrasonic power of 230 W. After treatment, it was centrifuged at 12900 rpm for 17 minutes, the supernatant was discarded, and the precipitate was also washed alternately with water and ethanol three times and freeze-dried at -43 ° C for 20 hours to finally obtain surface-modified Ti3C2T x Nanoribbons.

[0059] The Ti3C2T x The preparation method of the nanobelts is as follows: first, 11.5 parts of Ti3AlC2 powder are slowly added to 100.0 parts of 38% hydrofluoric acid HF solution, and the reaction is continued at 42 ° C with a magnetic stirring rate of 230 rpm for 23 hours to achieve selective etching of the Al layer in Ti3AlC2 to generate Ti3C2T x After the reaction, the mixture was centrifuged at 5300 rpm for 12 min, the supernatant was discarded and the precipitate was retained, and washed with deionized water 5 times, each time with 92 mL of washing solution, until the pH value of the washing solution was stable between 6.8. The obtained Ti3C2T x Ti3C2T was obtained after the wet precipitate was freeze-dried for 20 h. x powder, and then 2.3 parts of Ti3C2T x The powder was dispersed in 100 parts of 5.8 mol / L potassium hydroxide (KOH) solution and stirred at 27 °C for 23 h under nitrogen protection. The stirring rate was controlled at 280 rpm. During the reaction, Ti3C2T xThe sheets were gradually sheared and peeled along the interlayer direction in the alkaline solution to form a one-dimensional ribbon structure. After the reaction was completed, the system was centrifuged at 5300 rpm for 12 minutes, the supernatant was discarded, and the precipitate was retained and washed with deionized water until the pH value returned to 6.8. Finally, the obtained precipitate was dried under 0.06 MPa vacuum for 21 hours to obtain Ti3C2T x Nanoribbon powder.

[0060] The Ti3C2T x The average width of the nanoribbons is 80 nm; the average length is 2.1 μm; Ti3C2T x A two-dimensional carbide having a surface terminal group selected from fluorine (F), hydroxyl (OH) and oxygen (O);

[0061] The method for preparing a flexible antistatic and high temperature resistant FDC special film of this embodiment includes the following steps:

[0062] S1. Mix the polyimide / graphene precursor solution with the surface-modified Ti3C2T x The nanoribbons were mixed to form a dispersion under mechanical stirring at a stirring rate of 560 rpm, a stirring time of 46 min, and an ambient temperature of 27°C.

[0063] S2. The dispersion was heated and 3-aminopropyltriethoxysilane was added dropwise for functionalization; the mixture was heated to 83 ° C, the dropwise addition rate of 3-aminopropyltriethoxysilane was 0.2 mL / min, the stirring rate was 460 rpm, the reaction time was 69 min, and the reaction was carried out under nitrogen protection;

[0064] S3. Add 2,2'-dihydroxydiphenyl ether, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and diisononyl phthalate and mix at a constant temperature; stir at a constant temperature of 83 ° C for 35 min;

[0065] S4. Filtration and degassing followed by coating; the precursor solution was filtered through a 0.45 μm polytetrafluoroethylene membrane, the vacuum degassing pressure was -0.09 MPa, the degassing time was 23 min, the coating thickness was 59 μm, the scraping rate was 4 mm / s, the pre-drying temperature was 86 ° C, and the time was 39 min;

[0066] S5. Gradient heating and hot pressing curing and cooling to obtain the finished product; the hot pressing heating rate is 4°C / min, the heat treatment temperature is 265°C, the holding time is 1.8h, and the cooling rate is 1.3°C / min. The whole process is carried out under a nitrogen atmosphere.

[0067] Example 3

[0068] A flexible antistatic and high temperature resistant FDC special film, comprising the following raw materials in parts by weight: 79 parts of polyimide / graphene precursor solution, surface modified Ti3C2T x 5.4 parts of nanobelts, 0.8 parts of 3-aminopropyltriethoxysilane, 1.1 parts of 2,2'-dihydroxydiphenyl ether, 1.1 parts of 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt, and 2.2 parts of diisononyl phthalate.

[0069] The surface modified Ti3C2T x Nanobelts are Ti3C2T x The nanobelts were obtained by surface modification with 1-butyl-3-methylimidazolium tetrafluoroborate;

[0070] The preparation method of the polyimide / graphene precursor solution of this embodiment is as follows: 3.7 parts of reduced graphene oxide are added to 6 parts of N-methylpyrrolidone, and the reduced graphene oxide sheets are fully dispersed on the molecular scale by ultrasonic dispersion for 39 minutes to form a uniform and stable graphene dispersion; 10.2 parts of 4,4'-diaminodiphenyl ether are added to the above-mentioned graphene dispersion, and stirred and dissolved under nitrogen protection and a stirring rate of 360 rpm, and then the system is cooled to 3°C; 14.2 parts of 4,4'-diphenyl ether dianhydride are slowly added to the above-mentioned low-temperature solution in batches, and nitrogen protection is continued during the reaction process, the stirring rate is maintained at 360 rpm, the reaction system temperature is controlled at 3°C, and the gradual addition time is controlled at 3.1 hours. After the dianhydride is completely dissolved, the reaction is continued at a constant stirring rate for 6 hours to obtain a graphene-containing polyamic acid precursor solution, that is, a polyimide / graphene precursor solution.

[0071] The preparation method of reduced graphene oxide in this embodiment is as follows: 10.8 parts of graphene oxide are dispersed in 92.0 parts of deionized water, stirred at a stirring rate of 520 rpm for 39 minutes, and after forming a uniform dispersion, 3.2 parts of vitamin C reducing agent are slowly added to control the pH value of the system to be between 5.2, and then heated at 89° C. for 108 minutes. During the reaction, stirring is continued to ensure that the reduction reaction proceeds uniformly. After the reaction is completed, the resulting mixture is cooled to room temperature and centrifuged at 9200 rpm for 13 minutes to collect the precipitate. The supernatant is discarded and the mixture is repeatedly washed with deionized water four times, each time using 104 mL of washing solution, until the pH value of the washing solution stabilizes between 7.1. The resulting precipitate is dried under vacuum conditions of 0.07 MPa for 22 hours to obtain reduced graphene oxide.

[0072] The surface modified Ti3C2T x The preparation method of nanobelts is as follows: 1.3 parts of Ti3C2T xThe nanobelts were mixed with 2.6 parts of 1-butyl-3-methylimidazolium tetrafluoroborate in a planetary ball mill for 66 minutes. The obtained solid was added to 112 parts of a mixture of deionized water and anhydrous ethanol with a volume fraction of 2:1 and ultrasonically treated for 61 minutes at an ultrasonic power of 260 W. After treatment, it was centrifuged at 13800 rpm for 18 minutes, the supernatant was discarded, and the precipitate was also washed alternately with water and ethanol four times and freeze-dried at -46 ° C for 22 hours to finally obtain surface-modified Ti3C2T x Nanoribbons.

[0073] The Ti3C2T x The preparation method of the nanobelts is as follows: first, 13.0 parts of Ti3AlC2 powder are slowly added to 100.0 parts of 41% hydrofluoric acid HF solution, and the reaction is continued at 43 ° C with a magnetic stirring rate of 260 rpm for 24 hours to achieve selective etching of the Al layer in Ti3AlC2 to generate Ti3C2T x After the reaction, the mixture was centrifuged at 5600 rpm for 13 min, the supernatant was discarded and the precipitate was retained. It was washed with deionized water 5 times, with each washing liquid amount of 104 mL, until the pH value of the washing liquid was stable between 7.1. The obtained Ti3C2T x Ti3C2T was obtained after the wet precipitate was freeze-dried for 21 h. x powder, and then 2.6 parts of Ti3C2T x The powder was dispersed in 100 parts of potassium hydroxide (KOH) solution with a mass concentration of 6.1 mol / L, and stirred at 28 °C for 26 h under nitrogen protection. The stirring rate was controlled at 310 rpm. During the reaction, Ti3C2T x The sheets were gradually sheared and peeled along the interlayer direction in the alkaline solution to form a one-dimensional ribbon structure. After the reaction was completed, the system was centrifuged at 5600 rpm for 13 minutes, the supernatant was discarded, and the precipitate was retained and washed with deionized water until the pH value returned to 7.1. Finally, the obtained precipitate was dried under 0.07 MPa vacuum for 22 hours to obtain Ti3C2T x Nanoribbon powder.

[0074] The Ti3C2T x The average width of the nanoribbons is 110 nm; the average length is 2.7 μm; Ti3C2T x A two-dimensional carbide having a surface terminal group selected from fluorine (F), hydroxyl (OH) and oxygen (O);

[0075] The method for preparing a flexible antistatic and high temperature resistant FDC special film of this embodiment includes the following steps:

[0076] S1. Mix the polyimide / graphene precursor solution with the surface-modified Ti3C2T x The nanoribbons were mixed to form a dispersion under mechanical stirring at a stirring rate of 620 rpm, a stirring time of 52 min, and an ambient temperature of 28°C.

[0077] S2. The dispersion was heated and 3-aminopropyltriethoxysilane was added dropwise for functionalization; the mixture was heated to 86 ° C, the dropwise addition rate of 3-aminopropyltriethoxysilane was 0.2 mL / min, the stirring rate was 520 rpm, the reaction time was 78 min, and the reaction was carried out under nitrogen protection;

[0078] S3. Add 2,2'-dihydroxydiphenyl ether, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and diisononyl phthalate and mix at a constant temperature; the constant temperature stirring temperature is 86 ° C for 39 min;

[0079] S4. Filtration and degassing followed by coating; the precursor solution was filtered through a 0.45 μm polytetrafluoroethylene membrane, the vacuum degassing pressure was -0.09 MPa, the degassing time was 26 min, the coating thickness was 68 μm, the scraping rate was 4 mm / s, the pre-drying temperature was 92 ° C, and the time was 48 min;

[0080] S5. Gradient heating and hot pressing curing and cooling to obtain the finished product; the hot pressing heating rate is 4°C / min, the heat treatment temperature is 280°C, the holding time is 2.1h, and the cooling rate is 1.6°C / min. The whole process is carried out under a nitrogen atmosphere.

[0081] Example 4

[0082] A flexible antistatic and high temperature resistant FDC special film, comprising the following raw materials in parts by weight: 85 parts of polyimide / graphene precursor solution, surface modified Ti3C2T x 7.0 parts of nanobelts, 1.0 parts of 3-aminopropyltriethoxysilane, 1.5 parts of 2,2'-dihydroxydiphenyl ether, 1.5 parts of 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt, and 3.0 parts of diisononyl phthalate.

[0083] The surface modified Ti3C2T x Nanobelts are Ti3C2T x The nanobelts were obtained by surface modification with 1-butyl-3-methylimidazolium tetrafluoroborate;

[0084] The preparation method of the polyimide / graphene precursor solution of this embodiment is as follows: 4.5 parts of reduced graphene oxide are added to 8 parts of N-methylpyrrolidone, and the reduced graphene oxide sheets are fully dispersed on the molecular scale by ultrasonic dispersion for 45 minutes to form a uniform and stable graphene dispersion; 11.0 parts of 4,4'-diaminodiphenyl ether are added to the above-mentioned graphene dispersion, and stirred and dissolved under nitrogen protection and a stirring rate of 400 rpm, and then the system is cooled to 5°C; 15.0 parts of 4,4'-diphenyl ether dianhydride are slowly added to the above-mentioned low-temperature solution in batches, and nitrogen protection is continued during the reaction, the stirring rate is maintained at 400 rpm, the reaction system temperature is controlled at 5°C, and the gradual addition time is controlled at 3.5 hours. After the dianhydride is completely dissolved, the reaction is continued at a constant stirring rate for 7 hours to obtain a graphene-containing polyamic acid precursor solution, that is, a polyimide / graphene precursor solution.

[0085] The preparation method of reduced graphene oxide in this embodiment is as follows: 12.0 parts of graphene oxide are dispersed in 100.0 parts of deionized water, stirred at a stirring rate of 600 rpm for 45 minutes, and after forming a uniform dispersion, 4.0 parts of vitamin C reducing agent are slowly added to control the pH value of the system to be between 6.0, and then heated at 95° C. for 120 minutes. During the reaction, stirring is continued to ensure that the reduction reaction proceeds uniformly. After the reaction is completed, the resulting mixture is cooled to room temperature and centrifuged at 10,000 rpm for 15 minutes to collect the precipitate. The supernatant is discarded and the mixture is repeatedly washed with deionized water five times, each time using 120 mL of washing solution, until the pH value of the washing solution stabilizes between 7.5. The resulting precipitate is dried under vacuum conditions of 0.08 MPa for 24 hours to obtain reduced graphene oxide.

[0086] The surface modified Ti3C2T x The preparation method of nanobelts is as follows: 1.5 parts of Ti3C2T x The nanobelts were mixed with 3.0 parts of 1-butyl-3-methylimidazolium tetrafluoroborate in a planetary ball mill for 70 minutes. The obtained solid was added to 120 parts of a mixture of deionized water and anhydrous ethanol with a volume fraction of 2:1 and ultrasonically treated for 65 minutes at an ultrasonic power of 300 W. After treatment, the mixture was centrifuged at 15000 rpm for 20 minutes, the supernatant was discarded, and the precipitate was also washed alternately with water and ethanol for 4 times and freeze-dried at -50°C for 24 hours to obtain surface-modified Ti3C2T x Nanoribbons.

[0087] The Ti3C2T xThe preparation method of the nanobelts is as follows: first, 15.0 parts of Ti3AlC2 powder are slowly added to 100.0 parts of 45% hydrofluoric acid HF solution, and the reaction is continued at 45°C with a magnetic stirring rate of 300 rpm for 26 hours to achieve selective etching of the Al layer in Ti3AlC2 to generate Ti3C2T x After the reaction, the mixture was centrifuged at 6000 rpm for 15 min, the supernatant was discarded and the precipitate was retained. It was washed with deionized water for 6 times, with each washing liquid using 120 mL, until the pH value of the washing liquid was stable between 7.5. The obtained Ti3C2T x Ti3C2T was obtained after the wet precipitate was freeze-dried for 24 h. x powder, and then 3.0 parts of Ti3C2T x The powder was dispersed in 100 parts of 6.5 mol / L potassium hydroxide KOH solution and stirred at 30 °C for 30 h under nitrogen protection. The stirring rate was controlled at 350 rpm. During the reaction, Ti3C2T x The sheets were gradually sheared and peeled along the interlayer direction in the alkaline solution to form a one-dimensional ribbon structure. After the reaction was completed, the system was centrifuged at 6000 rpm for 15 min, the supernatant was discarded, and the precipitate was retained and washed with deionized water until the pH value returned to 7.5. Finally, the obtained precipitate was dried under 0.08 MPa vacuum conditions for 24 h to obtain Ti3C2T x Nanoribbon powder.

[0088] The Ti3C2T x The average width of the nanoribbons is 150nm; the average length is 3.5μm; Ti3C2T x A two-dimensional carbide having a surface terminal group selected from fluorine (F), hydroxyl (OH) and oxygen (O);

[0089] The method for preparing a flexible antistatic and high temperature resistant FDC special film of this embodiment includes the following steps:

[0090] S1. Mix the polyimide / graphene precursor solution with the surface-modified Ti3C2T x The nanoribbons were mixed to form a dispersion under mechanical stirring at a stirring rate of 700 rpm, a stirring time of 60 min, and an ambient temperature of 30°C.

[0091] S2. The dispersion was heated and 3-aminopropyltriethoxysilane was added dropwise for functionalization; the mixture was heated to 90 ° C, the dropwise addition rate of 3-aminopropyltriethoxysilane was 0.3 mL / min, the stirring rate was 600 rpm, the reaction time was 90 min, and the reaction was carried out under nitrogen protection;

[0092] S3. Add 2,2'-dihydroxydiphenyl ether, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and diisononyl phthalate and mix at a constant temperature; stir at a constant temperature of 90 ° C for 45 min;

[0093] S4. Filtration and degassing followed by film coating; the precursor solution was filtered through a 0.45 μm polytetrafluoroethylene membrane, the vacuum degassing pressure was -0.1 MPa, the degassing time was 30 min, the coating thickness was 80 μm, the scraping rate was 5 mm / s, the pre-drying temperature was 100 ° C, and the time was 60 min;

[0094] S5. Gradient heating and hot pressing curing and cooling to obtain the finished product; the hot pressing heating rate is 5°C / min, the heat treatment temperature is 300°C, the holding time is 2.5h, and the cooling rate is 2°C / min. The whole process is carried out under a nitrogen atmosphere.

[0095] Comparative Example 1

[0096] It is basically the same as Example 1, except that the amount of polyimide / graphene precursor solution is adjusted to 60 parts, resulting in decreased flexibility of the film material and poor conductive uniformity.

[0097] Comparative Example 2

[0098] It is basically the same as Example 1, except that the surface modified Ti3C2T x The amount of nanobelts used was 1.5 parts, the conductive network was insufficiently constructed, and the electrostatic performance was significantly deteriorated.

[0099] Comparative Example 3

[0100] It is basically the same as Example 1, except that 3-aminopropyltriethoxysilane is not added, the interface bonding force is poor, and the peeling strength of the film material is reduced.

[0101] Comparative Example 4

[0102] The process is basically the same as Example 1, except that 2,2'-dihydroxydiphenyl ether is not added, the thermal stability is significantly reduced, and obvious thermal decomposition occurs.

[0103] Comparative Example 5

[0104] It is basically the same as Example 1, except that 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt is not added, the conductivity of the film material decreases, and the static dissipation rate slows down.

[0105] Comparative Example 6

[0106] The same as Example 1, except that diisononyl phthalate was not added, and the film material was obviously brittle.

[0107] The flexibility cannot meet the bending test requirements.

[0108] Comparative Example 7

[0109] The results are basically the same as those in Example 1, except that the ultrasonic dispersion time of graphene is 10 min, the exfoliation of the layers is incomplete, and the composite system is uneven.

[0110] Comparative Example 8

[0111] It is basically the same as Example 1, except that Ti3C2T x The nanobelts were not modified with ionic liquids, and they aggregated severely in the polymer matrix, resulting in poor conductive stability.

[0112] Comparative Example 9

[0113] The same as Example 1, except that the etching temperature of Ti3AlC2 is 60℃, the reaction is intense and produces impurities, which affects the Ti3C2T x Purity and lamellar structure.

[0114] Comparative Example 10

[0115] It is basically the same as Example 1, except that the KOH shear peeling time is only 5h, and the Ti3C2T x The banded structure is not fully formed and the interface synergy is insufficient.

[0116] Comparative Example 11

[0117] It is basically the same as Example 1, except that the hot pressing heating rate is 10°C / min, which leads to large internal stress of the membrane material, loose structure, and easy cracking.

[0118] Comparative Example 12

[0119] The method is basically the same as Example 1, except that the amount of diisononyl phthalate added in step S3 is 5.0 parts (outside the scope of the claims), and the elongation at break of the film is improved.

[0120] Comparative Example 13

[0121] The method is basically the same as Example 1, except that the amount of 2,2'-dihydroxydiphenyl ether added in step S3 is 0.1 parts (lower than the claimed range), and the thermal decomposition temperature of the film is reduced.

[0122] Performance testing:

[0123] Surface Resistivity Test (Antistatic Performance): To evaluate the antistatic performance of FDC film, surface resistance was tested using standard method ASTM D257. A high resistance meter (such as the Keithley 6517B) was used to measure the film's surface resistance at a constant temperature (23±2°C) and relative humidity (50±5%), with a test voltage set to 100V. The film was cut into 10×10cm square samples and clamped between standard electrodes to measure its surface resistivity.

[0124] Thermal Stability Testing (High-Temperature Resistance): The thermal decomposition behavior of the FDC film under a nitrogen atmosphere was analyzed using a thermogravimetric analyzer (TGA, Thermo TGA Q500, etc.) according to ASTM E1131. A 5-10 mg sample was measured over a heating range of 10°C / min from room temperature to 800°C. Parameters such as the initial decomposition temperature (T5%) and the temperature of maximum weight loss (Tmax) were recorded to evaluate the thermal stability of the material.

[0125] Tensile Properties (Flexibility and Mechanical Properties): The tensile properties of the membranes were tested according to ASTM D882 using an electronic universal testing machine (e.g., Instron 3365). Samples were cut into rectangular strips 10 mm wide and 100 mm long. The breaking strength and elongation at break were measured at a tensile rate of 50 mm / min. These tests reflect the membrane's flexibility and mechanical strength, and were used to compare the structural optimization effects of the composite membranes at different component ratios.

[0126] Flexible Fatigue Cycle Testing: Flexible bending fatigue testing is performed according to Method B in ISO 7854. The film is bent and flexed 1,000 times at a specified radius (e.g., 5 mm) to observe whether surface cracks develop and whether conductivity decreases. Microscopic cracks are observed using SEM scanning to assess its reliability and durability in practical flexible electronics applications.

[0127] The properties of the special films of Examples 1 to 4 and Comparative Examples 1 to 13 are summarized in Table 1.

[0128] Table 1 Performance summary of special membranes of Examples 1 to 4 and Comparative Examples 1 to 13

[0129]

[0130] As can be seen from Table 1, the change in the amount of polyimide / graphene precursor solution will significantly affect the flexibility and conductive uniformity of the composite film. A low precursor content will lead to insufficient matrix network and reduced flexibility. At the same time, the graphene is unevenly distributed, resulting in discontinuous conductive channels and increased surface resistance. xThe amount of nanobelts added directly determines the efficiency of the conductive network construction. Insufficient addition will lead to sparse conductive paths, weak current carrying capacity, decreased electrostatic dissipation performance, and a significant increase in surface resistance. The introduction of 3-aminopropyltriethoxysilane can effectively improve the interfacial bonding between the inorganic nanobelts and the polymer matrix. Its absence will increase the risk of interfacial delamination, reduce mechanical strength, and easily produce cracks after flexible fatigue. 2,2'-dihydroxydiphenyl ether is a thermal stabilizer. Its absence will lower the thermal decomposition temperature of the polymer system, resulting in premature weight loss in the thermogravimetric curve, decreased thermal stability, and the material is prone to thermal decomposition during high-temperature use. 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt as an ionic liquid can improve the ionic conductivity of the system and the stability of the conductive network. Its absence will lead to a decrease in electron mobility, a slowdown in charge dissipation, and an increased risk of electrostatic accumulation. Diisononyl phthalate is a flexibility modifier. Its absence can make the material brittle, reduce elongation at break, reduce flexible fatigue performance, and easily crack during repeated bending. However, if added in excessive amounts, the material's mechanical strength may decrease, and it may even soften or deform. Insufficient ultrasonic dispersion time for graphene can lead to incomplete exfoliation and graphene agglomeration, resulting in internal inhomogeneity of the composite system and reduced conductivity and mechanical properties. x If the nanobelts are not modified with ionic liquids, they tend to aggregate in the matrix, destroying the continuity and stability of the conductive network, causing large fluctuations in conductivity, and negatively affecting the electrostatic dissipation performance. Too high a temperature for etching Ti3AlC2 will induce the formation of side reaction products, affecting the Ti3C2T x The structural integrity and purity of Ti3C2T will be reduced, thereby reducing its functional performance in the film, resulting in decreased conductivity and thermal stability. Insufficient KOH shear stripping time will lead to the x The banded structure is not fully formed, the lamellar dimensions are not ideal, and the interface synergy is weakened, affecting the overall performance. A hot pressing heating rate that is too fast will generate internal stress during the curing process, resulting in a loose structure of the film material, forming microcracks or wrinkles, and reducing flexible fatigue performance and mechanical strength. Although excessive use of flexible additives can improve elongation at break and bending properties, it may also cause surface stickiness and loose structure of the material, affecting dimensional stability. Insufficient use of thermal stabilizers will cause the film material to decompose prematurely or reduce the thermogravimetric residue rate in a high temperature environment, limiting its high-temperature application performance. The above factors interact with each other and jointly determine the key performance of the FDC specialty film, such as conductivity, thermal stability, flexibility and structural integrity.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that any equivalent structural transformations made within the scope of the present invention using the contents of the present invention's description and drawings should be included within the scope of protection of the claims of the present invention.

Claims

1. A flexible antistatic and high temperature resistant FDC special film, characterized in that: The raw materials include the following parts by weight: 70-85 parts of polyimide / graphene precursor solution, surface modification 3.0-7.0 parts of nanobelts, 0.5-1.0 parts of 3-aminopropyltriethoxysilane, 0.5-1.5 parts of 2,2'-dihydroxydiphenyl ether, 0.5-1.5 parts of 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt, and 1.0-3.0 parts of diisononyl phthalate; The surface modification Nanoribbons The nanobelts were obtained by surface modification with 1-butyl-3-methylimidazolium tetrafluoroborate; The The preparation method of nanobelts is as follows: first, take 10.0~15.0 parts The powder was slowly added to 100.0 parts of a 35% to 45% hydrofluoric acid (HF) solution and stirred at 40 to 45°C with a magnetic stirring rate of 200 to 300 rpm for 22 to 26 hours to achieve the desired effect. Selective etching of the Al layer After the reaction is completed, the mixture is centrifuged at 5000-6000 rpm for 10-15 min, the supernatant is discarded and the precipitate is retained, and washed with deionized water 4-6 times, with each washing liquid amount of 80-120 mL, until the pH value of the washing liquid is stable between 6.5 and 7.

5. The wet precipitate was freeze-dried for 18-24 h to obtain Powder, then 2.0~3.0 parts The powder was dispersed in 100 parts of a potassium hydroxide (KOH) solution with a mass concentration of 5.5-6.5 mol / L, and stirred at 25-30°C for 20-30 h under nitrogen protection. The stirring rate was controlled at 250-350 rpm. The sheets were gradually sheared and peeled along the interlayer direction in the alkaline solution to form a one-dimensional ribbon structure. After the reaction was completed, the system was centrifuged at 5000-6000 rpm for 10-15 min, the supernatant was discarded, the precipitate was retained and washed with deionized water until the pH value was restored to 6.5-7.5, and finally the obtained precipitate was dried under vacuum conditions of 0.05-0.08 MPa for 20-24 h to obtain Nanoribbon powder.

2. A flexible antistatic and high temperature resistant FDC special film according to claim 1, characterized in that: The preparation method of the polyimide / graphene precursor solution is as follows: 2.5-4.5 parts of reduced graphene oxide are added to 3-8 parts of N-methylpyrrolidone, and the reduced graphene oxide sheets are fully dispersed on a molecular scale by ultrasonic dispersion for 30-45 minutes to form a uniform and stable graphene dispersion; 9.0-11.0 parts of 4,4'-diaminodiphenyl ether are added to the above graphene dispersion, and stirred and dissolved under nitrogen protection and a stirring rate of 300-400 rpm, and then the system is cooled to 0-5°C; 13.0-15.0 parts of 4,4'-diphenyl ether dianhydride are slowly added to the above low-temperature solution in batches, and nitrogen protection is continuously maintained during the reaction process. The stirring rate is maintained at 300-400 rpm, the reaction system temperature is controlled at 0-5°C, and the gradual addition time is controlled at 2.5-3.5 hours. After the dianhydride is completely dissolved, the reaction is continued at a constant stirring rate for 5-7 minutes. h, obtaining a polyamic acid precursor solution containing graphene, that is, a polyimide / graphene precursor solution.

3. The flexible antistatic and high temperature resistant FDC special film according to claim 2, characterized in that: The reduced graphene oxide preparation method comprises the following steps: dispersing 9.0-12.0 parts of graphene oxide in 80.0-100.0 parts of deionized water, stirring at a stirring rate of 400-600 rpm for 30-45 minutes to form a uniform dispersion, slowly adding 2.0-4.0 parts of vitamin C reducing agent, controlling the pH value of the system to be between 4.0-6.0, then heating the reaction at 80-95°C for 90-120 minutes, continuously stirring during the reaction process to ensure that the reduction reaction proceeds uniformly, cooling the resulting mixture to room temperature after the reaction is completed, centrifuging at 8000-10000 rpm for 10-15 minutes to collect a precipitate, discarding the supernatant, and repeatedly washing with deionized water 3-5 times, each time using 80-120 mL of washing solution, until the pH value of the washing solution stabilizes at 6.5-7.5, and drying the resulting precipitate under vacuum conditions of 0.05-0.08 MPa for 18-24 hours to obtain reduced graphene oxide.

4. The flexible antistatic and high temperature resistant FDC special film according to claim 1, characterized in that: The surface modification The preparation method of nanobelts is as follows: 1.0~1.5 parts The nanobelts were mixed with 2.0-3.0 parts of 1-butyl-3-methylimidazolium tetrafluoroborate in a planetary ball mill for 60-70 minutes. The obtained solid was added to 100-120 parts of a mixture of deionized water and anhydrous ethanol with a volume fraction of 2:1 and ultrasonically treated for 55-65 minutes at an ultrasonic power of 200-300 W. After treatment, the nanobelts were centrifuged at 12000-15000 rpm for 15-20 minutes, the supernatant was discarded, and the obtained precipitate was also washed alternately with water and ethanol for 3-4 times and freeze-dried at -40--50°C for 18-24 hours to obtain the surface-modified nanobelts. Nanoribbons.

5. The flexible antistatic and high temperature resistant FDC special film according to claim 1, characterized in that: described The average width of the nanoribbons is 50~150 nm; the average length is 1.5~3.5 μm.

6. The flexible antistatic and high temperature resistant FDC special film according to claim 1, characterized in that: The It is a two-dimensional carbide whose surface terminal groups are selected from fluorine (F), hydroxyl (OH) and oxygen (O).

7. The method for preparing a flexible antistatic and high temperature resistant FDC special film according to claim 1, characterized in that: The following steps are involved: S1. Polyimide / graphene precursor solution and surface modification The nanoribbons are mixed to form a dispersion under mechanical stirring; S2. The dispersion was heated and 3-aminopropyltriethoxysilane was added dropwise for functionalization; S3. Add 2,2'-dihydroxydiphenyl ether, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and diisononyl phthalate and mix at a constant temperature; S4. Filtration and degassing followed by coating and film formation; S5. Gradual heating and hot pressing to solidify and cool to obtain the finished product.

8. The method for preparing a flexible antistatic and high temperature resistant FDC special film according to claim 7, characterized in that: The entire process of steps S1 to S5 is carried out under a nitrogen protective atmosphere; In step S1, the stirring rate is 500-700 rpm, the stirring time is 40-60 min, and the ambient temperature is 25-30°C; In step S2, the mixed solution is heated to 80-90° C., the dropwise addition rate of 3-aminopropyltriethoxysilane is 0.1-0.3 mL / min, the stirring rate is 400-600 rpm, the reaction time is 60-90 min, and the reaction is carried out under nitrogen protection; In step S3, the constant temperature stirring temperature is 80-90°C and the time is 30-45 min; In step S4, the precursor solution is filtered through a 0.45 μm polytetrafluoroethylene filter membrane. The vacuum degassing pressure is −0.08 to −0.1 MPa, and the degassing time is 20 to 30 min. The coating thickness is 50 to 80 μm, the scraping rate is 3 to 5 mm / s, the pre-drying temperature is 80 to 100°C, and the time is 30 to 60 min.

9. The method for preparing a flexible antistatic and high temperature resistant FDC special film according to claim 7, characterized in that: In step S5, the hot pressing heating rate is 3-5°C / min, the heat treatment temperature is 250-300°C, the holding time is 1.5-2.5 h, and the cooling rate is 1-2°C / min. The whole process is carried out under a nitrogen atmosphere.

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