Dielectric composition, polyimide electrolyte film, preparation method and application

Abstract

The invention relates to the technical field of energy storage materials, and particularly discloses a dielectric composition, a polyimide dielectric film, a preparation method and application. The dielectric composition provided by the invention comprises naphthylamine block polyamic acid, anhydride naphthalene block polyamic acid, polyamic acid and a transition metal phthalocyanine covalent organic framework material. The polyimide dielectric film prepared from the dielectric composition can still keep high energy density in a high-temperature environment, the energy storage density can reach 2.70 J / mm < 2 > or above under the condition of 150 DEG C, the breakdown field strength can reach 350 kV / mm or above, meanwhile, the polyimide dielectric film has good mechanical performance, the Young modulus can reach 2.2 GPa or above, balance of the high-temperature energy storage performance and the mechanical performance is achieved, and the polyimide dielectric film can be widely applied to the field of electronic devices. The material can be widely applied to the fields of high-temperature energy storage devices, aerospace power systems, high-temperature industrial sensors and the like, and has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage materials, and in particular to a dielectric composition, a polyimide dielectric film, and a preparation method and application thereof. Background Art

[0002] With the vigorous development of new energy vehicles, aerospace and other fields, higher requirements are placed on polymer film capacitors serving under extreme conditions. Under the coupling of multiple fields such as heat and electricity, the conduction loss of traditional polymer films will increase rapidly, resulting in serious degradation of their electrical insulation and energy storage performance. Although the most widely used biaxially oriented polypropylene (BOPP) exhibits a high breakdown strength at room temperature, its operating temperature is only 105°C. When the temperature continues to rise, the leakage current density inside the material rises rapidly, resulting in a sharp drop in the charging and discharging efficiency and energy density of the capacitor. As a result, traditional polymer dielectrics cannot meet the growing power demand in harsh environments.

[0003] As one of the polymer materials with good comprehensive performance, polyimide has a long-term working temperature range of -200 to 300 ° C, and can withstand high temperatures above 400 ° C. Compared with the most widely used BOPP dielectric film, it has a natural advantage in applications in extreme temperature environments, and it has a dielectric constant of 3.3 (BOPP is 2.2), which also means that polyimide has great potential for application in dielectric films for capacitors. However, the energy storage density of polyimide dielectric films at high temperatures is low, which greatly limits its application in the field of high-temperature dielectric energy storage. The existing technology generally improves the breakdown field strength of polyimide by adding a small amount of wide-bandgap inorganic nanoparticles, reduces the conductivity loss of polyimide films under high temperature conditions, and thus improves its high-temperature energy storage performance. However, the introduction of inorganic nanoparticle materials will reduce the flexibility and mechanical properties of polyimide dielectric films. Therefore, it is urgent to develop a polyimide dielectric film with both excellent high-temperature energy storage performance and mechanical properties. Summary of the invention

[0004] In view of the problem that the polyimide film in the prior art cannot have both high-temperature energy storage performance and mechanical properties, the present invention provides a dielectric composition, a polyimide dielectric film, and a preparation method and application. The polyimide electrolyte film provided by the present invention has few defects, high electron affinity, can effectively capture carriers at high temperatures, and significantly inhibits electron conduction, thereby having excellent high-temperature energy storage performance, and also has good mechanical properties, and has broad application prospects in the field of capacitors.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0006] In a first aspect, the present invention provides a dielectric composition, which includes a naphthylamine block polyamic acid represented by formula (I), a naphthalene anhydride block polyamic acid represented by formula (II), a polyamic acid represented by formula (III) and a transition metal phthalocyanine-based covalent organic framework material;

[0007]

[0008] Compared with the prior art, in the dielectric composition provided by the present invention, the naphthylamine block polyamic acid, the naphthalene anhydride block polyamic acid and the polyamic acid have good compatibility, which can reduce various defects of the naphthalene-containing polyimide film prepared therefrom; the molecular chain of the naphthalene-containing polyimide prepared therefrom is more rigid, the stacking is more orderly, the free volume is smaller, and the crystallization performance is better, therefore, it is beneficial to improve the energy storage density and the charge and discharge efficiency of the polyimide film, and reduce the conductivity loss of the polyimide film; and the naphthalene-containing polyimide has good heat resistance and can maintain good energy storage performance at high temperatures; at the same time, the naphthalene-containing polyimide prepared from the above three polyamic acids has a large conjugated structure, which is beneficial to improving electronic conductivity, and its conduction band and valence band electronic energy levels and band gap can effectively regulate the movement mode and path of carriers (holes and electrons), thereby improving energy storage performance; further, the transition The addition of metal phthalocyanine-based covalent organic framework materials can increase the polarization ability of polyimide film, thereby improving its dielectric constant, and it can form a good interface interaction with polyimide, effectively disperse the electric field stress, thereby improving the breakdown strength of the polyimide film; furthermore, the energy level difference between the transition metal phthalocyanine-based covalent organic framework material and the naphthalene-containing polyimide is large, which can produce a large energy barrier, which is conducive to the scattering of free charges and hinders the transfer of charges, so that the energy storage device maintains good performance in a wider temperature range. At the same time, the large energy barrier can enable the electrode material to store charges more effectively during the charging process. Therefore, the introduction of transition metal phthalocyanine-based covalent organic framework materials is also conducive to further improving the energy storage density; in addition, after the transition metal phthalocyanine-based covalent organic framework material is compounded with the naphthalene-containing polyimide, the flexibility and processing properties of the naphthalene-containing polyimide film can be effectively improved.

[0009] The polyimide film prepared from the dielectric composition provided by the present invention achieves a good balance between high-temperature energy storage performance, mechanical properties and thermal stability, overcoming the problem of traditional polyimide films that one performance is improved while other performances are reduced, which is conducive to broadening the application scope of polyimide materials and can be applied to high-performance material demand scenarios under a variety of complex working conditions, and has high practical value.

[0010] Furthermore, the structure of the transition metal phthalocyanine-based covalent organic framework material is shown in formula (IV):

[0011]

[0012] Wherein, M is Zn, Cu, Ni or Co.

[0013] The preferred transition metal phthalocyanine-based covalent organic framework material has certain similarities with polyimide in molecular structure and chemical properties, and the two can form good compatibility and interface interaction. This compatibility helps to improve the dispersibility and binding force of the covalent organic framework material in the polyimide film, thereby giving full play to its energy storage performance, and the above-mentioned transition metal phthalocyanine macrocyclic structure itself has high stability, and can maintain a stable structure and performance in a wide temperature range and different chemical environments, so that the energy storage device can still work normally under high temperature conditions, which is conducive to the preparation of energy storage devices with excellent high-temperature energy storage performance and mechanical properties.

[0014] Furthermore, the naphthylamine block polyamic acid shown in formula (I) is formed by condensation reaction of 1,4,5,8-naphthalenetetracarboxylic anhydride and diamine monomer; wherein the diamine monomer includes at least one of 4,4'-diaminodiphenylmethane, m-phenylenediamine, p-phenylenediamine, 1,3-bis(4-aminophenoxy)benzene, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 2-bis[4-(4-aminophenoxyphenyl)]propane or 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene.

[0015] As a specific embodiment of the present invention, the preparation method of the naphthylamine block polyamic acid shown in formula (I) comprises the following steps:

[0016] 1,4,5,8-naphthalenetetracarboxylic anhydride and diamine monomer are added into an organic solvent, stirred for reaction, and a naphthylamine-block polyamide acid solution is obtained.

[0017] Specifically, the organic solvent is N,N-dimethylacetamide or N-methylpyrrolidone; the stirring reaction temperature is 0° C. to 5° C., and the stirring reaction time is 2 h to 4 h.

[0018] Specifically, the molar ratio of the 1,4,5,8-naphthalenetetracarboxylic anhydride to the diamine monomer is 1:1000 to 1:100.

[0019] Specifically, the molar ratio of the diamine monomer to the organic solvent is 1:50 to 1:66.

[0020] Furthermore, the naphthalene anhydride block polyamic acid shown in formula (II) is formed by condensation reaction of 2,2'-dinaphthylbiphenyl-4,4'-diamine and a dianhydride monomer; wherein the dianhydride monomer is selected from at least one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-dibenzophenonetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bisphenol A type diether dianhydride, 4,4'-oxydiphthalic anhydride or dicyclohexyl-3,4',3,4'-tetracarboxylic dianhydride.

[0021] It should be noted that 2,2'-dinaphthylbiphenyl-4,4'-diamine was synthesized with reference to the literature High thermal stability and rigid rod of novel organosoluble polyimides and polyamides based on bulky and noncoplanar naphthalene-biphenyldiamine.

[0022] As a specific embodiment of the present invention, the preparation method of the naphthalene anhydride block polyamic acid shown in formula (II) comprises the following steps:

[0023] 2,2'-dinaphthylbiphenyl-4,4'-diamine and dianhydride monomer are added into an organic solvent, stirred and reacted to obtain a naphthalene anhydride block polyamic acid solution.

[0024] Specifically, the organic solvent is N,N-dimethylacetamide or N-methylpyrrolidone; the stirring reaction temperature is 0° C. to 5° C., and the stirring reaction time is 5 h to 6 h.

[0025] Specifically, the molar ratio of the 2,2'-dinaphthylbiphenyl-4,4'-diamine to the dianhydride monomer is 1:1000 to 1:100.

[0026] Specifically, the molar ratio of the dianhydride monomer to the organic solvent is 1:40 to 1:50.

[0027] Further, the polyamic acid represented by formula (III) is formed by a condensation reaction of a diamine monomer and a dianhydride monomer; wherein the diamine monomer includes at least one of 4,4'-diaminodiphenylmethane, m-phenylenediamine, p-phenylenediamine, 1,3-bis(4-aminophenoxy)benzene, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 2,2-bis[4-(4-aminophenoxyphenyl)]propane or 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene;

[0028] The dianhydride monomer is selected from at least one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bisphenol A type diether dianhydride, 4,4'-oxydiphthalic anhydride or dicyclohexyl-3,4',3,4'-tetracarboxylic dianhydride.

[0029] As a specific embodiment of the present invention, the preparation method of the polyamic acid represented by formula (III) comprises the following steps:

[0030] Add diamine monomer and dianhydride monomer into an organic solvent, stir and react to obtain a polyamic acid solution.

[0031] Specifically, the organic solvent is N,N-dimethylacetamide or N-methylpyrrolidone; the stirring reaction temperature is 0° C. to 5° C., and the stirring reaction time is 5 h to 6 h.

[0032] Specifically, the molar ratio of the diamine monomer to the dianhydride monomer is 1:1 to 1:1.2.

[0033] Specifically, the molar ratio of the diamine monomer to the organic solvent is 1:50 to 1:66.

[0034] As a specific embodiment of the present invention, the preparation method of the transition metal phthalocyanine-based covalent organic framework material comprises the following steps:

[0035] The tetraaminophthalocyanine transition metal salt and 1,4-naphthoquinone are dissolved in an organic solvent, anhydrous magnesium sulfate is added, and reflux reaction is carried out under an inert atmosphere, and the solid-liquid separation is performed, and the solid-liquid separation is performed, and the solid-liquid separation is performed, and the solid-liquid covalent organic framework material is obtained.

[0036] Specifically, the molar ratio of the tetraaminophthalocyanine transition metal salt, 1,4-naphthoquinone and anhydrous magnesium sulfate is 1:(4-4.2):(4-6).

[0037] Specifically, the tetraaminophthalocyanine transition metal salt is tetraaminophthalocyanine zinc, tetraaminophthalocyanine copper, tetraaminophthalocyanine nickel or tetraaminophthalocyanine cobalt.

[0038] Specifically, the molar ratio of the tetraaminophthalocyanine transition metal salt to the organic solvent is 1:10 to 1:15.

[0039] Specifically, the organic solvent is N,N-dimethylformamide.

[0040] Specifically, the heating reflux temperature is 60° C. to 66° C., and the reaction time is 50 h to 52 h.

[0041] It should be noted that the prepared transition metal phthalocyanine-based covalent organic framework material is dispersed in an organic solvent to obtain a transition metal phthalocyanine-based covalent organic framework material solution for standby use, wherein the molar ratio of the transition metal phthalocyanine-based covalent organic framework material to the organic solvent is 1:900 to 1:1100.

[0042] In a second aspect, the present invention also provides the use of the above dielectric composition in the preparation of a polyimide dielectric film.

[0043] In a third aspect, the present invention further provides a polyimide dielectric film prepared from any one of the dielectric compositions described above.

[0044] The polyimide dielectric film provided by the present invention can still maintain a high energy density under high temperature environment, and the energy storage density at 150°C can reach 2.70J / mm 2 The breakdown field strength can reach more than 350kV / mm. At the same time, it also has good mechanical properties, and the Young's modulus can reach more than 2.2GPa, achieving a balance between high-temperature energy storage performance and mechanical properties. It can be widely used in high-temperature energy storage devices, aerospace power systems, high-temperature industrial sensors and other fields, and has broad application prospects.

[0045] Furthermore, the thickness of the polyimide dielectric film is 8 μm to 16 μm.

[0046] In a fourth aspect, the present invention provides a method for preparing a polyimide dielectric film, comprising the following steps:

[0047] The naphthylamine block polyamic acid represented by formula (I), the naphthalene anhydride block polyamic acid represented by formula (II), the polyamic acid represented by formula (III) and a transition metal phthalocyanine-based covalent organic framework material are uniformly mixed, subjected to polycondensation reaction, cast into a film, and then the film is subjected to high-temperature imidization and peeled off from the substrate to obtain a polyimide dielectric film.

[0048] Furthermore, the temperature of the polycondensation reaction is 0°C to 5°C, and the time of the polycondensation reaction is 10h to 12h.

[0049] As a specific embodiment of the present invention, the method for preparing the polyimide dielectric film comprises the following steps:

[0050] S1, preparing a naphthylamine block polyamic acid solution: adding 1,4,5,8-naphthalenetetracarboxylic anhydride and the diamine monomer into an organic solvent, stirring and reacting, to obtain a naphthylamine block polyamic acid solution (solution a);

[0051] S2, preparing a polyamic acid solution: adding the diamine monomer and the dianhydride monomer into an organic solvent, stirring and reacting, to obtain a polyamic acid solution (solution b);

[0052] S3, preparing a naphthalene anhydride block polyamic acid solution: adding 2,2'-dinaphthylbiphenyl-4,4'-diamine and the dianhydride monomer into an organic solvent, stirring and reacting, to obtain a naphthalene anhydride block polyamic acid solution (solution c);

[0053] S4, dissolving a transition metal tetraaminophthalocyanine salt and 1,4-naphthoquinone in an organic solvent, adding anhydrous magnesium sulfate, heating under an inert atmosphere for reflux reaction, solid-liquid separation, washing, and drying to obtain a transition metal phthalocyanine-based covalent organic framework material; dispersing the prepared transition metal phthalocyanine-based covalent organic framework material in an organic solvent to obtain a transition metal phthalocyanine-based covalent organic framework material solution (solution d);

[0054] S5, casting and high-temperature imidization: after polycondensation reaction of solution a, solution b, solution c and solution d, casting film on a substrate, heat treating the film, peeling off from the substrate, and obtaining a polyamideimide dielectric film.

[0055] Specifically, in S5, the volume ratio of solution a, solution b, solution c and solution d is 1:(1-2):1:(1-2).

[0056] Specifically, in S5, the heat treatment adopts a gradient temperature increase method, and the specific steps are: first keep warm at 60℃~80℃ for 2h~5h, then keep warm at 100℃~120℃ for 2h~5h, keep warm at 150℃~180℃ for 2h~5h, keep warm at 200℃~240℃ for 2h~5h, and finally keep warm at 280℃~300℃ for 1h~2h.

[0057] By adopting the preferred gradient heating method, the polyimide molecular chains can be gradually arranged and cross-linked in order at different temperature stages, so that the molecular structure of the film is more regular and the internal stress distribution is more uniform, thereby improving the mechanical properties of the film. At the same time, through gradient heating, the polyimide molecules can fully undergo imidization reaction at different temperatures to form a more stable imide ring structure, improve the thermal stability and high temperature resistance of the film, and enable it to maintain good performance in a wider temperature range. At the same time, it is also beneficial to reduce various defects on the surface and inside of the film and improve the performance of the polyimide film.

[0058] The preparation process of the polyimide film provided by the invention is simple and suitable for large-scale industrial production and application.

[0059] In a fifth aspect, the present invention also provides application of the above-mentioned polyimide dielectric film in the field of energy storage capacitors.

[0060] In a sixth aspect, the present invention provides an energy storage capacitor comprising the above-mentioned polyimide dielectric film.

[0061] Compared with the prior art, the naphthalene-containing polyimide film provided by the present invention has a strong charge capture capability, can bind carriers in a trap region, and is beneficial to improving the breakdown field strength of the dielectric film. At the same time, the molecular chain of the naphthalene-containing polyimide is more rigid, the stacking is more orderly, has a smaller free volume, and has better crystallization performance, and maintains good flexibility and mechanical properties of the polymer. It still has a high energy storage density under high temperature and strong electric field, and its application in the development of energy storage devices has important research significance and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 The breakdown field strength diagram of the polyimide dielectric film prepared in Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention;

[0063] Figure 2 This is a breakdown field strength diagram of the polyimide dielectric films prepared in Examples 5 to 8 of the present invention and Comparative Examples 4 to 6. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0065] Example 1

[0066] This embodiment provides a method for preparing a polyimide dielectric film, comprising the following steps:

[0067] Step 1: preparing a naphthylamine block polyamic acid solution: dissolving 1,4,5,8-naphthalenetetracarboxylic anhydride and 2,2-bis[4-(4-aminophenoxyphenyl)]propane at a molar ratio of 1:1000 in N-methylpyrrolidone at a molar ratio of 50:1 to 2,2-bis[4-(4-aminophenoxyphenyl)]propane, and reacting the mixture under magnetic stirring at 2° C. for 3 h to obtain a naphthylamine block polyamic acid solution (solution a);

[0068] Step 2: preparing a polyamic acid solution: dissolving 2,2-bis[4-(4-aminophenoxyphenyl)]propane and 3,3',4,4'-benzophenonetetracarboxylic dianhydride in a molar ratio of 1:1.2 in N-methylpyrrolidone in a molar ratio of 50:1 to 2,2,2-bis[4-(4-aminophenoxyphenyl)]propane, and reacting at 3°C ​​with magnetic stirring for 6 hours to obtain a polyamic acid solution (solution b);

[0069] Step 3: preparing a naphthalene anhydride-blocked polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and 3,3',4,4'-benzophenonetetracarboxylic dianhydride in a molar ratio of 1:1000 in N-methylpyrrolidone in a molar ratio of 40:1 to 3,3',4,4'-benzophenonetetracarboxylic dianhydride, and reacting the mixture under magnetic stirring at 5°C for 5 hours to obtain a naphthalene anhydride-blocked polyamic acid solution (solution c);

[0070] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone at a molar ratio of 1:4, dissolve in DMF at a molar ratio of 10:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate at a molar ratio of 4:1 to zinc tetraaminophthalocyanine, heat and reflux for 52 hours under nitrogen at 60°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 12 hours to obtain N-ZnPc COF. N-ZnPc COF at a molar ratio of 1:600 ​​to 2,2-bis[4-(4-aminophenoxyphenyl)]propane monomer is dissolved in N-methylpyrrolidone at a molar ratio of 1000:1 to N-ZnPc COF, and magnetically stirred at 0°C for 10 hours to obtain a covalent organic framework solution (solution d);

[0071] Step 5: Casting and high-temperature imidization: Mix solution a, solution b, solution c and solution d in a volume ratio of 1:1:1:1.2, react with magnetic stirring at 0°C for 10 hours, and then cast a film on a substrate. Then, the film is subjected to high-temperature imidization by heat treatment at 70°C for 3 hours, 110°C for 4 hours, 165°C for 3 hours, 215°C for 3 hours, and 280°C for 2 hours. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0072] Example 2

[0073] This embodiment provides a method for preparing a polyimide dielectric film, comprising the following steps:

[0074] Step 1: preparing a naphthylamine block polyamic acid solution: dissolving 1,4,5,8-naphthalenetetracarboxylic anhydride and 4,4'-diaminodiphenylmethane at a molar ratio of 1:500 in N-methylpyrrolidone at a molar ratio of 58:1 to 4,4'-diaminodiphenylmethane, and reacting under magnetic stirring at 5° C. for 4 h to obtain a naphthylamine block polyamic acid solution (solution a);

[0075] Step 2: preparing a polyamic acid solution: dissolving 4,4'-diaminodiphenylmethane and 4,4'-oxydiphthalic anhydride in a molar ratio of 1:1.2 in N-methylpyrrolidone with a molar ratio of 58:1 to 4,4'-diaminodiphenylmethane, and reacting under magnetic stirring at 5°C for 6 hours to obtain a polyamic acid solution (solution b);

[0076] Step 3: preparing a naphthalene anhydride-blocked polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and 4,4'-oxydiphthalic anhydride in a molar ratio of 1:500 in N-methylpyrrolidone with a molar ratio of 45:1 to 4,4'-oxydiphthalic anhydride, and reacting the mixture under magnetic stirring at 5° C. for 6 h to obtain a naphthalene anhydride-blocked polyamic acid solution (solution c);

[0077] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone in a molar ratio of 1:4, dissolve in DMF with a molar ratio of 15:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate with a molar ratio of 4:1 to zinc tetraaminophthalocyanine, heat and reflux for 52 hours under nitrogen conditions at 60°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 24 hours to obtain N-ZnPc COF. N-ZnPc COF with a molar ratio of 1:400 to 4,4'-diaminodiphenylmethane monomer is dissolved in N-methylpyrrolidone with a molar ratio of 1000:1 to N-ZnPc COF, and magnetically stir at 5°C for 10 hours to obtain a covalent organic framework solution (solution d);

[0078] Step 5: Casting and high-temperature imidization: The volume ratio of solution a, solution b, solution c and solution d is 1:1:1:1.2, and after magnetic stirring at 5°C for 12 hours, the film is cast on a substrate, and then the film is subjected to high-temperature imidization by heat treatment at 60°C for 4 hours, 115°C for 3 hours, 170°C for 4 hours, 230°C for 4 hours, and 300°C for 1 hour. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0079] Example 3

[0080] This embodiment provides a method for preparing a polyimide dielectric film, comprising the following steps:

[0081] Step 1: preparing a naphthylamine block polyamic acid solution: dissolving 1,4,5,8-naphthalenetetracarboxylic anhydride and m-phenylenediamine at a molar ratio of 1:200 in N-methylpyrrolidone at a molar ratio of 63:1 to m-phenylenediamine, and reacting with magnetic stirring at 0° C. for 2 h to obtain a naphthylamine block polyamic acid solution (solution a);

[0082] Step 2: preparing a polyamic acid solution: dissolving m-phenylenediamine and bisphenol A diether dianhydride in a molar ratio of 1:1.2 in N-methylpyrrolidone in a molar ratio of 63:1 to m-phenylenediamine, and reacting under magnetic stirring at 0° C. for 5 h to obtain a polyamic acid solution (solution b);

[0083] Step 3: preparing a naphthalene anhydride block polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and bisphenol A type diether dianhydride in a molar ratio of 1:200 in N-methylpyrrolidone with a molar ratio of 46:1 to bisphenol A type diether dianhydride, and reacting with magnetic stirring at 0° C. for 5 h to obtain a naphthalene anhydride block polyamic acid solution (solution c);

[0084] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone in a molar ratio of 1:5, dissolve in DMF with a molar ratio of 12:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate with a molar ratio of 4:1 to zinc tetraaminophthalocyanine, heat and reflux for 51 hours under nitrogen conditions at 63°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol, respectively, and vacuum dry for 15 hours to obtain N-ZnPc COF. Dissolve N-ZnPcCOF with a molar ratio of 1:200 to m-phenylenediamine monomer in N-methylpyrrolidone with a molar ratio of 1000:1 to N-ZnPc COF, and obtain a covalent organic framework solution (solution d) after magnetic stirring at 2°C for 12 hours;

[0085] Step 5: Casting and high-temperature imidization: the volume ratio of solution a, solution b, solution c and solution d is 1:1.5:1:1.5, and after magnetic stirring for 10 hours at 0°C, the film is cast on a substrate, and then the film is subjected to high-temperature imidization by heat treatment, maintaining at 75°C for 4 hours, 105°C for 5 hours, 155°C for 3 hours, 220°C for 5 hours, and 290°C for 1 hour. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0086] Example 4

[0087] This embodiment provides a method for preparing a polyimide dielectric film, comprising the following steps:

[0088] Step 1: preparing a naphthylamine block polyamic acid solution: dissolving 1,4,5,8-naphthalenetetracarboxylic anhydride and 4,4'-diaminodiphenyl sulfone at a molar ratio of 1:100 in N-methylpyrrolidone at a molar ratio of 66:1 to 4,4'-diaminodiphenyl sulfone, and reacting with magnetic stirring at 3° C. for 2 h to obtain a naphthylamine block polyamic acid solution (solution a);

[0089] Step 2: preparing a polyamic acid solution: dissolving 4,4'-diaminodiphenyl sulfone and bisphenol A diether dianhydride in a molar ratio of 1:1.0 in N-methylpyrrolidone in a molar ratio of 66:1 to 4,4'-diaminodiphenyl sulfone, and reacting under magnetic stirring at 3°C ​​for 6 hours to obtain a polyamic acid solution (solution b);

[0090] Step 3: preparing a naphthalene anhydride poly-block amic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and bisphenol A type diether dianhydride in a molar ratio of 1:100 in N-methylpyrrolidone with a molar ratio of 50:1 to bisphenol A type diether dianhydride, and reacting with magnetic stirring at 3°C ​​for 5h to obtain a naphthalene anhydride block polyamic acid solution (solution c);

[0091] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone at a molar ratio of 1:6, dissolve in DMF at a molar ratio of 13:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate at a molar ratio of 4:1 to zinc tetraaminophthalocyanine, heat and reflux for 52 hours under nitrogen conditions at 60°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 15 hours to obtain N-ZnPc COF. N-ZnPc COF at a molar ratio of 1:100 to 4,4'-diaminodiphenyl sulfone monomer is dissolved in N-methylpyrrolidone at a molar ratio of 1000:1 to N-ZnPc COF, and magnetically stir at 0°C for 10 hours to obtain a covalent organic framework solution (solution d);

[0092] Step 5: Casting and high-temperature imidization: Mix solution a, solution b, solution c and solution d in a volume ratio of 1:2:1:2, react with magnetic stirring at 2°C for 11 hours, and then cast a film on a substrate. Then, the film is subjected to high-temperature imidization by heat treatment, maintaining at 65°C for 4 hours, 115°C for 3 hours, 160°C for 4 hours, 230°C for 3 hours, and 285°C for 2 hours. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0093] Example 5

[0094] This embodiment provides a method for preparing a polyimide dielectric film, comprising the following steps:

[0095] Step 1: naphthylamine block polyamic acid solution: 1,4,5,8-naphthalenetetracarboxylic anhydride and p-phenylenediamine in a molar ratio of 1:1000 are dissolved in N-methylpyrrolidone in a molar ratio of 60:1 to p-phenylenediamine, and the mixture is reacted at 2° C. with magnetic stirring for 4 hours to obtain a naphthylamine block polyamic acid solution (solution a);

[0096] Step 2: preparing a polyamic acid solution: dissolving p-phenylenediamine and 3,3',4,4'-biphenyltetracarboxylic dianhydride in a molar ratio of 1:1.2 in N-methylpyrrolidone in a molar ratio of 60:1 to p-phenylenediamine, and reacting under magnetic stirring at 0° C. for 5 h to obtain a polyamic acid solution (solution b);

[0097] Step 3: preparing a naphthalene anhydride-blocked polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and 3,3',4,4'-biphenyltetracarboxylic dianhydride in a molar ratio of 1:1000 in N-methylpyrrolidone in a molar ratio of 42:1 to 3,3',4,4'-biphenyltetracarboxylic dianhydride, and reacting with magnetic stirring at 2°C for 5 hours to obtain a naphthalene anhydride-blocked polyamic acid solution (solution c);

[0098] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone in a molar ratio of 1:4, dissolve in DMF with a molar ratio of 10:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate with a molar ratio of 4:1 to zinc tetraaminophthalocyanine, heat and reflux for 50 hours under nitrogen conditions at 66°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 24 hours to obtain N-ZnPc COF. Dissolve N-ZnPcCOF with a molar ratio of 1:600 ​​to p-phenylenediamine monomer in N-methylpyrrolidone with a molar ratio of 1000:1 to N-ZnPc COF, and obtain a covalent organic framework solution (solution d) after magnetic stirring at 0°C for 12 hours;

[0099] Step 5: Casting and high-temperature imidization. The volume ratio of solution a, solution b, solution c and solution d is 1:1.2:1:1.5. After magnetic stirring at 0°C for 12 hours, the film is cast on a substrate. The film is then subjected to high-temperature imidization by heat treatment, maintaining at 60°C for 4 hours, 110°C for 3 hours, 170°C for 3 hours, 230°C for 2 hours, and 285°C for 1 hour. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0100] Example 6

[0101] This embodiment provides a method for preparing a polyimide dielectric film, comprising the following steps:

[0102] Step 1: preparing a naphthylamine block polyamic acid solution: dissolving 1,4,5,8-naphthalenetetracarboxylic anhydride and 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene at a molar ratio of 1:500 in N-methylpyrrolidone at a molar ratio of 53:1 to 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, and reacting the mixture under magnetic stirring at 5° C. for 3 h to obtain a naphthylamine block polyamic acid solution (solution a);

[0103] Step 2: preparing a polyamic acid solution: dissolving 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene and dicyclohexyl-3,4',3,4'-tetracarboxylic dianhydride in a molar ratio of 1:1.2 in N-methylpyrrolidone in a molar ratio of 53:1 to 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, and reacting at 3°C ​​with magnetic stirring for 6 hours to obtain a polyamic acid solution (solution b);

[0104] Step 3: preparing a naphthalene anhydride-blocked polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and dicyclohexyl-3,4',3,4'-tetracarboxylic dianhydride in a molar ratio of 1:500 in N-methylpyrrolidone having a molar ratio of 44:1 to dicyclohexyl-3,4',3,4'-tetracarboxylic dianhydride, and reacting the mixture under magnetic stirring at 2° C. for 5 h to obtain a naphthalene anhydride-blocked polyamic acid solution (solution c);

[0105] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone at a molar ratio of 1:5, dissolve in DMF at a molar ratio of 15:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate at a molar ratio of 4.2:1 to zinc tetraaminophthalocyanine, heat and reflux for 52 hours under nitrogen conditions at 60°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 20 hours to obtain N-ZnPc COF. N-ZnPc COF at a molar ratio of 1:400 to 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene monomer is dissolved in N-methylpyrrolidone at a molar ratio of 1000:1 to N-ZnPc COF, and magnetically stir at 0°C for 10 hours to obtain a covalent organic framework solution (solution d);

[0106] Step 5: Casting and high-temperature imidization: Mix solution a, solution b, solution c and solution d in a volume ratio of 1:1:1:1, react with magnetic stirring at 5°C for 10 hours, and then cast a film on a substrate. Then, the film is subjected to high-temperature imidization by heat treatment at 70°C for 3 hours, 110°C for 3 hours, 160°C for 3 hours, 220°C for 3 hours, and 290°C for 2 hours. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0107] Example 7

[0108] This embodiment provides a method for preparing a polyimide dielectric film, comprising the following steps:

[0109] Step 1: preparing a naphthylamine block polyamic acid solution: dissolving 1,4,5,8-naphthalenetetracarboxylic anhydride and 1,3-bis(4-aminophenoxy)benzene at a molar ratio of 1:200 in N-methylpyrrolidone at a molar ratio of 55:1 to 1,3-bis(4-aminophenoxy)benzene, and reacting the mixture under magnetic stirring at 0° C. for 2 h to obtain a naphthylamine block polyamic acid solution (solution a);

[0110] Step 2: preparing a polyamic acid solution: dissolving 1,3-bis(4-aminophenoxy)benzene and 1,2,4,5-cyclohexanetetracarboxylic dianhydride in a molar ratio of 1:1.2 in N-methylpyrrolidone in a molar ratio of 55:1 to 1,3-bis(4-aminophenoxy)benzene, and reacting under magnetic stirring at 2° C. for 6 h to obtain a polyamic acid solution (solution b);

[0111] Step 3: preparing a naphthalene anhydride-blocked polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride in a molar ratio of 1:200 in N-methylpyrrolidone in a molar ratio of 40:1 to 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, and reacting with magnetic stirring at 0°C for 5 hours to obtain a naphthalene anhydride-blocked polyamic acid solution (solution c);

[0112] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone in a molar ratio of 1:4, dissolve in DMF with a molar ratio of 10:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate with a molar ratio of 4.1:1 to zinc tetraaminophthalocyanine, heat and reflux for 50 hours under nitrogen conditions at 65°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 15 hours to obtain N-ZnPc COF. N-ZnPc COF with a molar ratio of 1:200 to 1,3-bis(4-aminophenoxy)benzene monomer is dissolved in N-methylpyrrolidone with a molar ratio of 1000:1 to N-ZnPc COF, and magnetically stir at 5°C for 12 hours to obtain a covalent organic framework solution (solution d);

[0113] Step 5: Casting and high-temperature imidization: Mix solution a, solution b, solution c and solution d in a volume ratio of 1:1:1:1.2, react with magnetic stirring at 0°C for 11 hours, and then cast a film on a substrate. Then, the film is subjected to high-temperature imidization by heat treatment, maintaining at 80°C for 2 hours, 20°C for 2 hours, 180°C for 2 hours, 240°C for 2 hours, and 300°C for 1 hour. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0114] Example 8

[0115] This embodiment provides a method for preparing a polyimide dielectric film, comprising the following steps:

[0116] Step 1: preparing a naphthylamine block polyamic acid solution: dissolving 1,4,5,8-naphthalenetetracarboxylic anhydride and 4,4'-diaminodiphenyl ether at a molar ratio of 1:100 in N-methylpyrrolidone at a molar ratio of 50:1 to 4,4'-diaminodiphenyl ether, and reacting with magnetic stirring at 0° C. for 2 h to obtain a naphthylamine block polyamic acid solution (solution a);

[0117] Step 2: preparing a polyamic acid solution: dissolving 4,4'-diaminodiphenyl ether and pyromellitic anhydride in a molar ratio of 1:1.1 in N-methylpyrrolidone with a molar ratio of 50:1 to 4,4'-diaminodiphenyl ether, and reacting under magnetic stirring at 0 °C for 5 h to obtain a polyamic acid solution (solution b);

[0118] Step 3: preparing a naphthalene anhydride-blocked polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and pyromellitic acid dianhydride in a molar ratio of 1:100 in N-methylpyrrolidone with a molar ratio of 45:1 to pyromellitic acid dianhydride, and reacting with magnetic stirring at 0°C for 5 hours to obtain a naphthalene anhydride-blocked polyamic acid solution (solution c);

[0119] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone in a molar ratio of 1:4, dissolve in DMF with a molar ratio of 10:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate with a molar ratio of 4:1 to zinc tetraaminophthalocyanine, heat and reflux for 50 hours under nitrogen conditions at 60°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 18 hours to obtain N-ZnPc COF. Dissolve N-ZnPc COF with a molar ratio of 1:100 to 4,4'-diaminodiphenyl ether monomer in N-methylpyrrolidone with a molar ratio of 1:1000 to N-ZnPc COF, and obtain a covalent organic framework solution (solution d) after magnetic stirring at 0°C for 11 hours;

[0120] Step 5: Casting and high-temperature imidization: The volume ratio of solution a, solution b, solution c and solution d is 1:1:1:1.2, and after magnetic stirring at 5°C for 12 hours, the film is cast on a substrate, and then the film is subjected to high-temperature imidization by heat treatment, maintaining at 60°C for 5 hours, 100°C for 5 hours, 150°C for 5 hours, 200°C for 5 hours, and 280°C for 2 hours. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0121] Comparative Example 1

[0122] This comparative example provides a method for preparing a polyimide dielectric film, which is different from Example 3 only in that solution a, solution c and solution d are not added during the preparation process, and specifically comprises the following steps:

[0123] Step 1: preparing a polyamic acid solution: dissolving m-phenylenediamine and bisphenol A diether dianhydride in a molar ratio of 1:1.2 in N-methylpyrrolidone in a molar ratio of 63:1 to m-phenylenediamine, and reacting under magnetic stirring at 0° C. for 5 h to obtain a polyamic acid solution (solution b);

[0124] Step 2: Casting and high-temperature imidization: Solution b is cast into a film on a substrate, and then the film is subjected to high-temperature imidization by heat treatment, maintaining at 75°C for 4 hours, 105°C for 5 hours, 155°C for 3 hours, 220°C for 5 hours, and 290°C for 1 hour. After peeling off from the substrate, the naphthalene block-type polyimide / covalent organic framework dielectric film is obtained.

[0125] Comparative Example 2

[0126] This comparative example provides a method for preparing a polyimide dielectric film, which is different from Example 3 only in that solution d is not added during the preparation process, and specifically comprises the following steps:

[0127] Step 1: preparing a naphthylamine block polyamic acid solution: dissolving 1,4,5,8-naphthalenetetracarboxylic anhydride and m-phenylenediamine at a molar ratio of 1:200 in N-methylpyrrolidone at a molar ratio of 63:1 to m-phenylenediamine, and reacting with magnetic stirring at 0° C. for 2 h to obtain a naphthylamine block polyamic acid solution (solution a);

[0128] Step 2: preparing a polyamic acid solution: dissolving m-phenylenediamine and bisphenol A diether dianhydride in a molar ratio of 1:1.2 in N-methylpyrrolidone in a molar ratio of 63:1 to m-phenylenediamine, and reacting under magnetic stirring at 0° C. for 5 h to obtain a polyamic acid solution (solution b);

[0129] Step 3: preparing a naphthalene anhydride block polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and bisphenol A type diether dianhydride in a molar ratio of 1:200 in N-methylpyrrolidone with a molar ratio of 46:1 to bisphenol A type diether dianhydride, and reacting with magnetic stirring at 0° C. for 5 h to obtain a naphthalene anhydride block polyamic acid solution (solution c);

[0130] Step 4: Casting and high-temperature imidization: Solution a, solution b, and solution c are mixed in a volume ratio of 1:1.5:1, and magnetically stirred at 0°C for 10 hours, and then cast on a substrate to form a film. The film is then subjected to high-temperature imidization by heat treatment at 75°C for 4 hours, 105°C for 5 hours, 155°C for 3 hours, 220°C for 5 hours, and 290°C for 1 hour. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0131] Comparative Example 3

[0132] This comparative example provides a method for preparing a polyimide dielectric film, which is different from Example 3 only in that solution a is not added during the preparation process, and specifically comprises the following steps:

[0133] Step 1: preparing a polyamic acid solution: dissolving m-phenylenediamine and bisphenol A diether dianhydride in a molar ratio of 1:1.2 in N-methylpyrrolidone in a molar ratio of 63:1 to m-phenylenediamine, and reacting under magnetic stirring at 0° C. for 5 h to obtain a polyamic acid solution (solution b);

[0134] Step 2: preparing a naphthalene anhydride block polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and bisphenol A type diether dianhydride in a molar ratio of 1:200 in N-methylpyrrolidone with a molar ratio of 46:1 to bisphenol A type diether dianhydride, and reacting with magnetic stirring at 0°C for 5 hours to obtain a naphthalene anhydride block polyamic acid solution (solution c);

[0135] Step 3: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone in a molar ratio of 1:5, dissolve in DMF with a molar ratio of 12:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate with a molar ratio of 4:1 to zinc tetraaminophthalocyanine, heat and reflux for 51 hours under nitrogen conditions at 63°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 15 hours to obtain N-ZnPc COF. Dissolve N-ZnPcCOF with a molar ratio of 1:200 to m-phenylenediamine monomer in N-methylpyrrolidone with a molar ratio of 1000:1 to N-ZnPc COF, and obtain a covalent organic framework solution (solution d) after magnetic stirring at 2°C for 12 hours;

[0136] Step 4: Casting and high-temperature imidization: The volume ratio of solution b, solution c and solution d is 1.5:1:1.5, and after magnetic stirring for 10 hours at 0°C, the film is cast on a substrate, and then the film is subjected to high-temperature imidization by heat treatment, maintaining at 75°C for 4 hours, 105°C for 5 hours, 155°C for 3 hours, 220°C for 5 hours, and 290°C for 1 hour. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0137] Comparative Example 4

[0138] This comparative example provides a method for preparing a polyimide dielectric film, which specifically comprises the following steps:

[0139] Step 1: Preparation of anhydride-terminated flexible polyamic acid precursor A: Dissolve the flexible diamine 4,4'-diaminodiphenyl ether and the flexible dibasic acid anhydride bisphenol A type diether dianhydride in N-methylpyrrolidone with a molar ratio of 50:1 to 4,4'-diaminodiphenyl ether at a molar ratio of 1:1.2, and stir for 4 hours under nitrogen protection at 0°C to obtain anhydride-terminated flexible polyamic acid precursor A;

[0140] Step 2: Preparation of amine-terminated flexible polyamic acid precursor B: Dissolve the flexible diamine 4,4'-diaminodiphenyl ether and the flexible dibasic acid anhydride bisphenol A type diether dianhydride in N-methylpyrrolidone with a molar ratio of 50:1 to 4,4'-diaminodiphenyl ether at a molar ratio of 1:1.1, and stir for 4 hours under nitrogen protection at 0°C to obtain amine-terminated flexible polyamic acid precursor B;

[0141] Step 3: Preparation of amine-terminated rigid polyamic acid precursor D: rigid diamine p-phenylenediamine and rigid dibasic acid anhydride 3,3',4,4'-biphenyltetracarboxylic dianhydride are dissolved in N-methylpyrrolidone with a molar ratio of 50:1 to p-phenylenediamine at a molar ratio of 1:1.2, and stirred at 0°C under nitrogen protection for 4 hours to obtain amine-terminated rigid polyamic acid precursor D;

[0142] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone in a molar ratio of 1:4, dissolve in DMF with a molar ratio of 10:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate with a molar ratio of 4:1 to zinc tetraaminophthalocyanine, heat and reflux for 50 hours under nitrogen conditions at 66°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 24 hours to obtain N-ZnPc COF. Dissolve N-ZnPcCOF with a molar ratio of 1:600 ​​to p-phenylenediamine monomer in N-methylpyrrolidone with a molar ratio of 1000:1 to N-ZnPc COF, and obtain a covalent organic framework solution (solution d) after magnetic stirring at 0°C for 12 hours;

[0143] Step 5: Casting and high-temperature imidization. The volume ratio of anhydride-terminated flexible polyamic acid precursor A, amine-terminated flexible polyamic acid precursor B, amine-terminated rigid polyamic acid precursor D, and solution d is 1:1.2:1:1.5. After magnetic stirring at 0°C for 12 hours, the film is cast on a substrate. The film is then subjected to high-temperature imidization by heat treatment, maintaining at 60°C for 4 hours, 110°C for 3 hours, 170°C for 3 hours, 230°C for 2 hours, and 285°C for 1 hour. After peeling off from the substrate, the naphthalene-containing block polyimide / covalent organic framework dielectric film is obtained.

[0144] Comparative Example 5

[0145] This comparative example provides a method for preparing a polyimide dielectric film, which specifically comprises the following steps:

[0146] Step 1: Preparation of anhydride-terminated flexible polyamic acid precursor A: Dissolve the flexible diamine 4,4'-diaminodiphenyl ether and the flexible dibasic acid anhydride bisphenol A type diether dianhydride in N-methylpyrrolidone with a molar ratio of 50:1 to 4,4'-diaminodiphenyl ether at a molar ratio of 1:1.2, and stir for 4 hours under nitrogen protection at 0°C to obtain anhydride-terminated flexible polyamic acid precursor A;

[0147] Step 2: Preparation of amine-terminated rigid polyamic acid precursor C: rigid diamine p-phenylenediamine and rigid dibasic acid anhydride 3,3',4,4'-biphenyltetracarboxylic dianhydride are dissolved in N-methylpyrrolidone with a molar ratio of 50:1 to p-phenylenediamine at a molar ratio of 1:1.1, and stirred for 4 hours under nitrogen protection at 0°C to obtain amine-terminated flexible polyamic acid precursor C;

[0148] Step 3: Preparation of amine-terminated rigid polyamic acid precursor D: rigid diamine p-phenylenediamine and rigid dibasic acid anhydride 3,3',4,4'-biphenyltetracarboxylic dianhydride are dissolved in N-methylpyrrolidone with a molar ratio of 50:1 to p-phenylenediamine at a molar ratio of 1:1.2, and stirred at 0°C under nitrogen protection for 4 hours to obtain amine-terminated rigid polyamic acid precursor D;

[0149] Step 4: Prepare a covalent organic framework solution: Mix zinc tetraaminophthalocyanine and 1,4-naphthoquinone in a molar ratio of 1:4, dissolve in DMF with a molar ratio of 10:1 to zinc tetraaminophthalocyanine, add anhydrous magnesium sulfate with a molar ratio of 4:1 to zinc tetraaminophthalocyanine, heat and reflux for 50 hours under nitrogen conditions at 66°C, then filter, wash the obtained solid with distilled water, benzene and anhydrous ethanol respectively, and vacuum dry for 24 hours to obtain N-ZnPc COF. Dissolve N-ZnPcCOF with a molar ratio of 1:600 ​​to p-phenylenediamine monomer in N-methylpyrrolidone with a molar ratio of 1000:1 to N-ZnPc COF, and obtain a covalent organic framework solution (solution d) after magnetic stirring at 0°C for 12 hours;

[0150] Step 5: Casting and high-temperature imidization. The volume ratio of anhydride-terminated flexible polyamic acid precursor A, amine-terminated flexible polyamic acid precursor C, amine-terminated rigid polyamic acid precursor D, and solution d is 1:1.2:1:1.5. After magnetic stirring at 0°C for 12 hours, the film is cast on a substrate. The film is then subjected to high-temperature imidization by heat treatment, maintaining at 60°C for 4 hours, 110°C for 3 hours, 170°C for 3 hours, 230°C for 2 hours, and 285°C for 1 hour. After peeling off from the substrate, the naphthalene-containing block polyimide / covalent organic framework dielectric film is obtained.

[0151] Comparative Example 6

[0152] This comparative example provides a method for preparing a polyimide dielectric film, which is different from Example 8 in that the covalent organic framework N-CuPc COF is replaced with a metal organic framework ZIF-8, and specifically comprises the following steps:

[0153] Step 1: preparing a naphthylamine block polyamic acid solution: dissolving 1,4,5,8-naphthalenetetracarboxylic anhydride and 4,4'-diaminodiphenyl ether at a molar ratio of 1:100 in N-methylpyrrolidone at a molar ratio of 50:1 to 4,4'-diaminodiphenyl ether, and reacting with magnetic stirring at 0° C. for 2 h to obtain a naphthylamine block polyamic acid solution (solution a);

[0154] Step 2: preparing a polyamic acid solution: dissolving 4,4'-diaminodiphenyl ether and pyromellitic anhydride in a molar ratio of 1:1.1 in N-methylpyrrolidone with a molar ratio of 50:1 to 4,4'-diaminodiphenyl ether, and reacting under magnetic stirring at 0 °C for 5 h to obtain a polyamic acid solution (solution b);

[0155] Step 3: preparing a naphthalene anhydride-blocked polyamic acid solution: dissolving 2,2'-dinaphthylbiphenyl-4,4'-diamine and pyromellitic acid dianhydride in a molar ratio of 1:100 in N-methylpyrrolidone with a molar ratio of 45:1 to pyromellitic acid dianhydride, and reacting with magnetic stirring at 0°C for 5 hours to obtain a naphthalene anhydride-blocked polyamic acid solution (solution c);

[0156] Step 4: Prepare ZIF-8 solution: Dissolve 0.79g of dimethylimidazole and 0.45g of zinc nitrate in 40mL of methanol respectively, then mix the two solutions and let stand for 24h, wash with methanol and centrifuge, and place in a 120℃ oven to dry for 12h to obtain ZIF-8. Dissolve ZIF-8 and 4,4'-diaminodiphenyl ether monomer in N-methylpyrrolidone with a molar ratio of 1:100 to ZIF-8 at a molar ratio of 1000:1, and stir magnetically at 0℃ for 10h to obtain a metal organic framework solution (solution e);

[0157] Step 5: Casting and high-temperature imidization: Mix solution a, solution b, solution c and solution e in a volume ratio of 1:1:1:1.2, react with magnetic stirring at 5°C for 12 hours, and then cast a film on a substrate. Then, the film is subjected to high-temperature imidization by heat treatment, maintaining at 60°C for 5 hours, 100°C for 5 hours, 150°C for 5 hours, 200°C for 5 hours, and 280°C for 2 hours. After peeling off from the substrate, the naphthalene block polyimide / covalent organic framework dielectric film is obtained.

[0158] In order to better reflect the performance of the naphthalene block-type polyimide / covalent organic framework dielectric films prepared in Examples 1 to 8 and Comparative Examples 1 to 6 of the present invention, the breakdown field strength and high-temperature energy storage density tests were performed on each naphthalene block-type polyimide / covalent organic framework dielectric film at 150°C, wherein the Young's modulus was obtained by measuring the stress-strain curve of the sample using a dynamic thermal analyzer (DiscoveryDMA 850). The breakdown field strength test was performed using a PolyK CPE1901 ferroelectric polarization test system, applying a 500V / s DC voltage until breakdown. The high-temperature energy storage density was calculated by measuring the DE loop, which was tested using a ferroelectric analyzer (Huace FE-2000), wherein a triangular unipolar pulse voltage waveform with a frequency of 100Hz was applied. During this test, the instrument recorded the relationship between the electric field (E) and the electric displacement (D), thereby drawing the DE loop, and the energy storage density can be calculated by the area under the loop. Electrical measurements under high voltage were performed in a silicone oil bath. The results are shown in Table 1.

[0159] Table 1

[0160]

[0161]

[0162] The breakdown field strengths in Table 1 were tested at 150° C. using a PolyK CPE1901 ferroelectric polarization test system by applying a 500 V / s DC voltage until breakdown. The breakdown field strengths of Examples 1 to 8 and Comparative Examples 1 to 6 were tested at 150° C.

[0163] It can be seen from the data in Table 1 that the naphthalene block-type polyimide / covalent organic framework dielectric film prepared by the method in the embodiment of the present invention in Examples 1 to 8 has a higher breakdown field strength and energy storage density at a high temperature of 150°C. Examples 1 to 8 all added different amounts of 1,4,5,8-naphthalenetetracarboxylic anhydride and N-ZnPc COF, and Comparative Examples 1 to 3 did not add 1,4,5,8-naphthalenetetracarboxylic anhydride or N-ZnPc COF. Comparative Examples 4 to 5 used rigid polyamic acid segments and flexible polyamic acid segments to prepare naphthalene block-type polyimide / covalent organic framework dielectric films, and Comparative Example 6 used the metal organic framework ZIF-8 to prepare a naphthalene block-type polyimide / metal organic framework dielectric film. The test data show that the breakdown field strength and energy storage density of the naphthalene block-type polyimide dielectric film at 150°C are higher than those of the pure polyimide dielectric film. The monomer 1,4,5,8-naphthalenetetracarboxylic anhydride and organic filler N-ZnPc COF in the naphthalene-embedded polyimide / covalent organic framework dielectric film have strong charge capture ability at high temperature, which can confine the carriers in the trap area and significantly improve the breakdown field strength and energy storage density of the dielectric film.

[0164] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A dielectric composition, characterized in that: It includes naphthylamine block polyamic acid shown in formula (I), naphthalene anhydride block polyamic acid shown in formula (II), polyamic acid shown in formula (III) and transition metal phthalocyanine-based covalent organic framework material; 2. The dielectric composition according to claim 1, wherein The structure of the metal phthalocyanine-based covalent organic framework material is shown in formula (IV): Wherein, M is Zn, Cu, Ni or Co.

3. The dielectric composition according to claim 1, wherein The naphthylamine block polyamic acid shown in formula (I) is formed by condensation reaction of 1,4,5,8-naphthalenetetracarboxylic anhydride and diamine monomer; wherein the diamine monomer includes at least one of 4,4'-diaminodiphenylmethane, m-phenylenediamine, p-phenylenediamine, 1,3-bis(4-aminophenoxy)benzene, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 2,2-bis[4-(4-aminophenoxyphenyl)]propane or 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene.

4. The dielectric composition according to claim 1, wherein The naphthalene anhydride block polyamic acid shown in formula (II) is formed by condensation reaction of 2,2'-dinaphthylbiphenyl-4,4'-diamine and dianhydride monomer; wherein the dianhydride monomer is selected from at least one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bisphenol A type diether dianhydride, 4,4'-oxydiphthalic anhydride or dicyclohexyl-3,4',3,4'-tetracarboxylic dianhydride.

5. The dielectric composition according to claim 1, wherein The polyamic acid represented by formula (III) is formed by a condensation reaction of a diamine monomer and a dianhydride monomer; wherein the diamine monomer comprises at least one of 4,4'-diaminodiphenylmethane, m-phenylenediamine, p-phenylenediamine, 1,3-bis(4-aminophenoxy)benzene, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 2,2-bis[4-(4-aminophenoxyphenyl)]propane or 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene; The dianhydride monomer is selected from at least one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bisphenol A type diether dianhydride, 4,4'-oxydiphthalic anhydride or dicyclohexyl-3,4',3,4'-tetracarboxylic dianhydride.

6. The dielectric composition according to claim 1 or 2, characterized in that: The preparation method of the transition metal phthalocyanine-based covalent organic framework material comprises the following steps: The tetraaminophthalocyanine transition metal salt and 1,4-naphthoquinone are dissolved in an organic solvent, anhydrous magnesium sulfate is added, and reflux reaction is carried out under an inert atmosphere, and the solid-liquid separation is performed, and the solid-liquid separation is performed, and the solid-liquid separation is performed, and the solid-liquid covalent organic framework material is obtained.

7. Use of the dielectric composition according to any one of claims 1 to 6 in the preparation of a polyimide dielectric film.

8. A polyimide dielectric film, characterized in that: The dielectric composition is prepared from the dielectric composition according to any one of claims 1 to 6.

9. The method for preparing a polyimide dielectric film according to claim 8, characterized in that: The steps include: The naphthylamine block polyamic acid represented by formula (I), the naphthalene anhydride block polyamic acid represented by formula (II), the polyamic acid represented by formula (III) and a transition metal phthalocyanine-based covalent organic framework material are uniformly mixed, subjected to polycondensation reaction, cast into a film, and then the film is subjected to high-temperature imidization and peeled off from the substrate to obtain a polyimide dielectric film.

10. Use of the polyimide dielectric film according to claim 8 in the field of energy storage capacitors.

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