A BOPP / single-layer two-dimensional polymer composite film with high dielectric properties and a preparation method thereof

Abstract

The present invention discloses a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties and a preparation method thereof, belonging to the technical field of capacitor metallization dielectric films. (1) Surface treatment of BOPP film; (2) TAPB and TPOC with different lengths of alkoxy chains; x Dissolve them in organic solvents respectively; (3) Prepare TAPB and TPOC x The solutions are mixed, and the mixed solution is dripped and spread on the surface of ultrapure water in the LB film drawing machine tank, and the mixture is left to stand until the solution evaporates; (4) the LB film drawing machine slide barrier speed is set to compress; (5) glacial acetic acid is dripped to make it spread on the surface of ultrapure water in the LB film drawing machine tank, and the mixture is left to react; (6) the LB film drawing machine slide barrier speed is set to compress to form a single-layer two-dimensional polymer film; (7) the single-layer two-dimensional polymer film is transferred to the surface of the BOPP film for deposition to form a composite film. The present invention prepares a composite film by depositing a single-molecular layer of two-dimensional polymer on the BOPP film, inhibits the charge migration at the electrode-medium interface, and improves the insulation properties of the film.

Description

Technical Field

[0001] The invention relates to the technical field of capacitor metallized dielectric films, and in particular to a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties and a preparation method thereof. Background Art

[0002] With the depletion of fossil fuels and other energy sources and the continuous growth of society's demand for energy, improving the consumption and storage capacity of new energy has become an important guarantee for promoting the sustainable development of society. Metallized film capacitors are widely used in power electronic equipment due to their high power density, strong voltage resistance, long service life, and stable performance. They are core energy storage devices in the fields of electromagnetic pulse emission devices, electric vehicles, and power systems. As power electronic equipment develops towards miniaturization and large capacity, higher requirements are placed on the energy storage density of metallized film capacitors. The development of high energy storage density dielectric films is the core technology to achieve high energy storage of capacitors.

[0003] Biaxially oriented polypropylene (BOPP) is the most widely used energy storage dielectric material in metallized film capacitors due to its high breakdown strength, low dielectric loss, high charge and discharge efficiency, and good self-healing performance. However, the energy storage density of BOPP film is relatively low and cannot meet the demand for high energy storage density capacitors. Therefore, improving the energy storage density of BOPP film is of great significance for the development of high-performance capacitors. The energy storage density of dielectric film is mainly determined by the breakdown strength and dielectric constant. Improving the breakdown strength and dielectric constant of the film is an important method for obtaining high-performance dielectric materials. The present invention proposes a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties and a preparation method thereof. Summary of the invention

[0004] The purpose of the present invention is to provide a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties and a preparation method thereof, wherein a single-molecular layer of two-dimensional polymer is deposited on the BOPP film to inhibit charge migration at the electrode-medium interface and improve the insulation properties of the film.

[0005] To achieve the above objectives, the present invention provides a method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties, wherein a single-molecular layer of two-dimensional polymer is deposited on a BOPP film to prepare a composite film, thereby inhibiting charge migration at the electrode-dielectric interface and improving the insulating properties of the film.

[0006] Preferably, a method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties specifically comprises the following steps:

[0007] (1) Surface treatment of BOPP film;

[0008] (2) TAPB and TPOC with different alkoxy chain lengths x Dissolved in organic solvents respectively;

[0009] (3) Prepare TAPB and TPOC x The solutions are mixed, and the mixed solution is dropped and spread on the surface of ultrapure water in the LB film drawing machine tank, and the solution is compressed after evaporation;

[0010] (4) adding glacial acetic acid dropwise to spread it on the surface of ultrapure water in the LB film drawing machine tank, allowing it to react and then compressing it to form a single-layer two-dimensional polymer film;

[0011] (5) The single-layer two-dimensional polymer film is transferred to the surface of the BOPP film and deposited to form a composite film.

[0012] Preferably, the specific operation of step (1) is: using anhydrous ethanol and deionized water to wash the BOPP film for 5 to 15 minutes, and then putting the washed BOPP film into a vacuum drying oven and drying it at 50 to 70° C. for 0.5 to 2 hours.

[0013] Preferably, in step (1), the thickness of the BOPP film is 3 to 10 μm.

[0014] Preferably, in step (2), TAPB and TPOC are dissolved x The organic solvents are chloroform and N,N-dimethylformamide.

[0015] Preferably, in step (2), TPOC x The alkoxy chain length is 0-12.

[0016] Preferably, in step (3), TAPB and TPOC x The molar ratio of the solution is 2:3, the concentration of the mixed solution is 0.5 to 2 mg / mL, and the drop volume is 50 to 250 μL.

[0017] Preferably, in step (5), the volume of glacial acetic acid is 350 μL.

[0018] Preferably, in steps (4) and (6), the sliding barrier speed of the LB film drawing machine is set to compress at a speed of 2.98 mm / min.

[0019] Preferably, in step (7), the single-layer two-dimensional polymer film is transferred to the surface of the BOPP film by a vertical pulling method at a film pulling speed of 0.5 mm / min.

[0020] Therefore, the present invention provides a method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties, in which a single-molecular layer of two-dimensional polymer is deposited on the BOPP film, thereby inhibiting charge migration at the electrode-dielectric interface and improving the insulation properties of the film; a BOPP-based composite film with high dielectric properties is obtained, thereby promoting the miniaturization and high integration of power electronic equipment.

[0021] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of BOPP / single-layer two-dimensional polymer composite film;

[0023] Figure 2 This is a comparison diagram of the surface morphology of the BOPP / single-layer two-dimensional polymer composite film prepared in Example 1 of the present invention and a common BOPP film;

[0024] Figure 3 This is a surface element distribution diagram of the BOPP / single-layer two-dimensional polymer composite film prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The present invention provides a method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties, wherein a single-layer two-dimensional polymer is deposited on a BOPP film to obtain a composite film, thereby inhibiting charge migration at the electrode-medium interface and improving the insulation properties of the film. The structural schematic diagram of the obtained composite film is shown in FIG. Figure 1 shown.

[0026] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] This embodiment provides a method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties, and the specific steps are as follows:

[0029] (1) A BOPP film with a thickness of 7.5 μm was selected, and the BOPP film was cleaned in anhydrous ethanol and deionized water for 10 min respectively, and then the cleaned BOPP film was placed in a vacuum drying oven at a temperature of 60°C and dried for 1 h.

[0030] (2) 1,3,5-tri(4-aminophenyl)benzene (TAPB) was dissolved in chloroform to obtain a 1 mg / mL TAPB solution, and 2,5-dioxy-1,4-terephthalaldehyde (TPOC0) having an alkoxy chain length of 0 was dissolved in N,N-dimethylformamide to obtain a TPOC0 solution with a concentration of 1 mg / mL.

[0031] (3) The completely dissolved TAPB and TPOC0 solutions were mixed evenly in a molar ratio of 2:3. 200 μL of the mixed solution of TAP B and TPOC0 was taken and added dropwise to evenly spread the mixed solution on the surface of the ultrapure water in the LB tank. The mixture was allowed to stand for 30 min to allow the solvent to evaporate.

[0032] (4) Set the slide barrier of the LB film drawing machine to compress at a speed of 2.98 mm / min to a molding pressure of 3 mN / m.

[0033] (5) Spread 350 μL of glacial acetic acid evenly on the surface of ultrapure water in the LB tank and let it stand for 12 h to allow the reaction to complete.

[0034] (6) The slide barrier of the LB film drawing machine is set to compress at a speed of 2.98 mm / min to a film forming pressure to form a single-layer two-dimensional polymer film.

[0035] (7) A single layer of two-dimensional polymer was transferred to the surface of BOPP film using a vertical pulling method at a film pulling speed of 0.5 mm / min.

[0036] Example 2

[0037] This embodiment provides a method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties, which is different from Embodiment 1 in that:

[0038] In step (2), 1,3,5-tri(4-aminophenyl)benzene (TAPB) is dissolved in chloroform to obtain a 1 mg / mL TAPB solution, and 2,5-dioxy-1,4-terephthalaldehyde (TPOC2) having an alkoxy chain length of 2 is dissolved in N,N-dimethylformamide to obtain a TPOC2 solution with a concentration of 1.5 mg / mL.

[0039] In step (3), the completely dissolved TAPB and TPOC2 solutions are mixed evenly in a molar ratio of 2:3. 150 μL of the mixed solution of TAPB and TPOC2 is taken and dripped onto the surface of the ultrapure water in the LB tank to make it evenly spread. The mixture is allowed to stand for 30 minutes to allow the solvent to evaporate.

[0040] The rest are the same as in Example 1 and will not be repeated here.

[0041] Example 3

[0042] This embodiment provides a method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties, which is different from Embodiment 1 in that:

[0043] In step (2), 1,3,5-tri(4-aminophenyl)benzene (TAPB) is dissolved in chloroform to obtain a 1 mg / mL TAPB solution, and 2,5-dioxy-1,4-terephthalaldehyde (TPOC4) having an alkoxy chain length of 4 is dissolved in N,N-dimethylformamide to obtain a TPOC4 solution with a concentration of 1 mg / mL.

[0044] In step (3), the completely dissolved TAPB and TPOC4 solutions are mixed evenly in a molar ratio of 2:3. 70 μL of the mixed solution of TAPB and TPOC4 is taken and dripped onto the surface of the ultrapure water in the LB tank to make it evenly spread. The mixture is allowed to stand for 30 minutes to allow the solvent to evaporate.

[0045] The rest are the same as in Example 1 and will not be repeated here.

[0046] Example 4

[0047] This embodiment provides a method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties, which is different from Embodiment 1 in that:

[0048] In step (2), 1,3,5-tri(4-aminophenyl)benzene (TAPB) is dissolved in chloroform to obtain a 1 mg / mL TAPB solution, and 2,5-dioxy-1,4-terephthalaldehyde (TPOC8) having an alkoxy chain length of 8 is dissolved in N,N-dimethylformamide to obtain a TPOC8 solution with a concentration of 1 mg / mL.

[0049] In step (3), the completely dissolved TAPB and TPOC8 solutions were mixed evenly in a molar ratio of 2:3. 70 μL of the mixed solution of TAPB and TPOC8 was taken and dripped onto the surface of the ultrapure water in the LB tank to make it evenly spread. The mixture was allowed to stand for 30 min to allow the solvent to evaporate.

[0050] The rest are the same as in Example 1 and will not be repeated here.

[0051] Example 5

[0052] This embodiment provides a method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties, which is different from Embodiment 1 in that:

[0053] In step (2), 1,3,5-tri(4-aminophenyl)benzene (TAPB) is dissolved in chloroform to obtain a 1 mg / mL TAPB solution, and 2,5-dioxy-1,4-terephthalaldehyde (TPOC 12 ) was dissolved in N,N-dimethylformamide to obtain TPOC with a concentration of 1 mg / mL 12 Solution.

[0054] In step (3), the completely dissolved TAPB and TPOC 12 The solution was mixed evenly in a molar ratio of 2:3, and TAPB and TPOC were taken. 12 70 μL of the mixed solution was added dropwise to evenly spread on the surface of ultrapure water in the LB tank, and allowed to stand for 30 min to allow the solvent to evaporate.

[0055] The rest are the same as in Example 1 and will not be repeated here.

[0056] Figure 2 The surface morphology of the ordinary BOPP film and the BOPP / single-layer two-dimensional polymer composite film prepared in Example 1-5 is shown. As can be seen from the figure, the single-layer two-dimensional polymer in Example 1-5 is successfully deposited on the BOPP film.

[0057] Figure 3 The surface element distribution of the BOPP / single-layer two-dimensional polymer composite film prepared in Examples 1 to 5 is shown. As can be seen from the figure, the single-layer two-dimensional polymer deposited in Examples 1 to 5 is evenly distributed on the BOPP.

[0058] Table 1 shows the breakdown strength of BOPP and Examples 1-5 at different temperatures.

[0059] Table 1

[0060]

[0061] It can be seen from the data in Table 1 that compared with pure BOPP film, the breakdown field strength of BOPP / single-layer two-dimensional polymer composite film is significantly improved.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties, characterized in that: Depositing a monolayer of two-dimensional polymer on a BOPP film to obtain a composite film inhibits charge migration at the electrode-medium interface and improves the insulation properties of the film; The specific steps include: (1) Surface treatment of BOPP film; (2) TAPB and 2,5-dialkoxy-1,4-terephthalaldehyde (TPOC) with an alkoxy carbon chain length of 0-12 x Dissolved in organic solvents respectively; (3) Prepare TAPB and TPOC x The solutions are mixed, and the mixed solution is dropped and spread on the surface of ultrapure water in the LB film drawing machine tank, and allowed to stand until the solvent evaporates; (4) Setting the sliding speed compression of the LB film drawing machine; (5) Add glacial acetic acid dropwise to spread it on the surface of ultrapure water in the LB film drawing machine tank and let it stand for reaction; (6) Setting the sliding barrier speed of the LB film drawing machine to compress and form a single-layer two-dimensional polymer film; (7) The single-layer two-dimensional polymer film is transferred to the surface of the BOPP film and deposited to form a composite film.

2. The method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties according to claim 1, characterized in that: The specific operation of step (1) is: using anhydrous ethanol and deionized water to wash the BOPP film for 5-15 minutes, and then putting the washed BOPP film into a vacuum drying oven and drying it at 50-70° C. for 0.5-2 hours.

3. The method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties according to claim 1, characterized in that: In the step (1), the thickness of the BOPP film is 3-10 μm.

4. The method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties according to claim 1, characterized in that: In step (2), TAPB and TPOC are dissolved x The organic solvents are chloroform and N,N-dimethylformamide.

5. The method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties according to claim 1, characterized in that: In step (3), TAPB and TPOC x The molar ratio of the solution is 2:3, the concentration of the mixed solution is 0.5~2 mg / mL, and the drop volume is 50~250 μL.

6. The method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties according to claim 1, characterized in that: In step (5), the volume of glacial acetic acid is 350 μL.

7. The method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties according to claim 1, characterized in that: In the steps (4) and (6), the sliding speed of the LB film drawing machine is set to compress at a speed of 2.98 mm / min.

8. The method for preparing a BOPP / single-layer two-dimensional polymer composite film with high dielectric properties according to claim 1, characterized in that: In the step (7), the single-layer two-dimensional polymer film is transferred to the surface of the BOPP film by a vertical pulling method at a film pulling speed of 0.5 mm / min.

Images