Metallized film for capacitor and preparation method

Abstract

The invention discloses a metallized film for a capacitor and a preparation method, and belongs to the technical field of capacitors. Comprising the following steps: preparing a polypropylene film layer; preparing the medium base layer: S21, preparing polyacrylamide; s22, preparing amine methylated polyacrylamide by taking formaldehyde, dimethylamine and polyacrylamide as raw materials; s23, preparing nano titanium dioxide; s24, mercaptopropyl trimethoxy silane and nano titanium dioxide are used as raw materials to prepare sulfhydrylated nano titanium dioxide; s25, castor oil and sulfhydrylated nano titanium dioxide are subjected to a click chemical reaction, and modified castor oil is obtained; s26, preparing modified polyacrylamide by taking the aminomethylated polyacrylamide solution and the modified castor oil as raw materials; s26, coating one side surface of the polypropylene film layer with modified polyacrylamide, and performing hot pressing to obtain a medium base layer; and S3, plating the dielectric base layer with a metal material to form a metallized layer, thereby obtaining the metallized film for the capacitor with good conductivity.

Description

Technical Field

[0001] The present invention belongs to the technical field of capacitors, and in particular relates to a metallized film for capacitors and a preparation method thereof. Background Art

[0002] Metallized film capacitors use a plastic material such as polypropylene film or polyester film as a substrate. Metal material is deposited onto the substrate surface via vacuum evaporation to serve as electrodes, and then the capacitor is formed by winding or stacking. Because the interfacial free energy between the evaporated metal material and the plastic substrate is typically greater than the surface free energy between metal atoms, the metal material cannot wet the substrate well. This lack of wetting results in the metal-deposited layer forming islands with gaps between the islands. Current must flow around these gaps, increasing path resistance and forming a high-resistance contact interface. This results in poor electrical performance for the capacitor, limiting its practical application. Summary of the Invention

[0003] The object of the present invention is to provide a metallized film for capacitors and a preparation method thereof, which can be used to improve the wetting performance between the metal material and the substrate and reduce the power transmission loss.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for preparing a metallized film for a capacitor comprises the following steps:

[0006] S1, preparing a polypropylene film layer;

[0007] S2. Prepare the dielectric base layer:

[0008] S21, preparing polyacrylamide;

[0009] S22, preparing aminomethylated polyacrylamide using formaldehyde, dimethylamine and polyacrylamide as raw materials;

[0010] S23, preparing nano titanium dioxide;

[0011] S24, preparing mercaptolated nano-titanium dioxide using mercaptopropyltrimethoxysilane and nano-titanium dioxide as raw materials;

[0012] S25, performing a click chemistry reaction using castor oil and thiol-modified nano-titanium dioxide to obtain modified castor oil;

[0013] S26, preparing modified polyacrylamide using aminomethylated polyacrylamide solution and modified castor oil as raw materials;

[0014] S26, coating the modified polyacrylamide on one side of the polypropylene film layer, and hot pressing at 65-75° C. for 2-3 hours to obtain a dielectric base layer;

[0015] S3. Using a metal material as a vapor deposition material, plating the metal material onto the side of the dielectric substrate containing the modified polyacrylamide to form a metallization layer, thereby obtaining the metallization film for the capacitor.

[0016] As a preferred technical solution of the present invention, in step S3, the metal material is selected from any one of Ag, Al, Cu, Au, Ni, and Ge.

[0017] As a preferred technical solution of the present invention, in step S3, the vacuum degree of the evaporation process is less than 1.2×10 -4 Pa.

[0018] As a preferred technical solution of the present invention, in step S3, the evaporation rate of the evaporation process is 3-4 Å / s.

[0019] As a preferred technical solution of the present invention, in step S3, the evaporation current of the evaporation process is 70-80A.

[0020] As a preferred technical solution of the present invention, in step S3, the evaporation voltage of the evaporation process is 1-3V.

[0021] As a preferred technical solution of the present invention, in step S3, the evaporation time of the evaporation process is 15-25 seconds.

[0022] The metallized film for capacitors is prepared by the above-mentioned preparation method.

[0023] Beneficial effects of the present invention:

[0024] The invention utilizes polyacrylamide to react with formaldehyde and dimethylamine to generate aminomethylated polyacrylamide through a Mannich reaction; introduces a thiol-containing coupling agent onto the surface of nano-titanium dioxide to generate a click reaction with the olefinic bonds of castor oil to obtain modified castor oil grafted with nano-titanium dioxide; and then reacts the modified castor oil with the aminomethylated polyacrylamide through an amidation reaction to obtain a dielectric material. The strong adhesion between the nano-titanium dioxide and the evaporated metal is utilized to enhance the wettability between the evaporated metal and the polypropylene base layer, thereby effectively inhibiting the diffusion of metal atoms. A continuous, smooth, high-quality metallized film is prepared with good anti-peeling performance, ensuring component structural stability, high dielectric strength and low square resistance, and reducing power transmission loss. DETAILED DESCRIPTION

[0025] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0026] Example 1

[0027] A metallized film for capacitors and a preparation method thereof, comprising the following steps:

[0028] S1, preparing a polypropylene film layer;

[0029] 88 parts by mass of homopolymer polypropylene resin, 1 part by mass of antioxidant, and 10 parts by mass of anhydrous ethanol were mixed and stirred for 30 minutes, filtered, and the solid phase was dried in an 80°C oven for 5 hours. The mixture was melt-blended by a twin-screw extruder, extruded into pellets, and cast into a film by a multi-layer extruder. The film was then biaxially stretched to obtain a polypropylene film layer with a uniform thickness of 2 μm.

[0030] The antioxidant is any one of antioxidant 1076, antioxidant 1010, antioxidant 1024 and antioxidant 168;

[0031] The temperature conditions of the twin-screw extruder are: zone 1 150°C; zone 2 160°C; zone 3 180°C; zone 4 190°C; zones 5-8 200°C; zone 9 190°C; zone 10 185°C; zone 11 180°C; die head 175°C;

[0032] The casting process conditions are as follows: barrel zone temperature 160°C → 210°C → 230°C → 230°C; screen changing zone temperature 230°C → 215°C → 215°C → 215°C; distribution zone temperature 215°C → 210°C → 200°C → 200°C; die temperature 190°C; casting roller temperature 80°C; casting speed 1.0 m / min;

[0033] The stretching conditions are: stretching ratio 4×4; stretching rate 100% / s; preheating temperature 165° C.; preheating time 65 s; annealing temperature 80° C.;

[0034] The homopolymer polypropylene resin is selected from Lanzhou Petrochemical H9018;

[0035] S2. Prepare the dielectric base layer:

[0036] S21. In a nitrogen atmosphere, acrylamide, sodium formate, and deionized water were mixed, heated to 30°C and stirred for 10 minutes, ammonium persulfate was added, and stirred at 65°C for 2 hours. The mixture was poured into methanol, stirred for 2 minutes, filtered, and the solid phase was washed with methanol to obtain polyacrylamide; the mass ratio of acrylamide, sodium formate, deionized water, and ammonium persulfate was 8:0.01:200:0.008;

[0037] S22, taking a 40% formaldehyde aqueous solution, adding a 33% dimethylamine aqueous solution by mass, stirring for 30 minutes, adding a 2% polyacrylamide aqueous solution by mass, and continuing to stir for 4 hours to obtain an aminomethylated polyacrylamide solution; wherein the volume ratio of the formaldehyde aqueous solution, the dimethylamine aqueous solution, and the polyacrylamide aqueous solution is 6:0.2:1;

[0038] S23. Mix butyl titanate, anhydrous ethanol, and deionized water, stir for 5 minutes, add glacial acetic acid, stir for 20 minutes, vacuum dry at 120° C. for 10 hours, calcine at 250° C. for 1 hour, and grind to obtain nano-titanium dioxide; the ratio of butyl titanate, anhydrous ethanol, deionized water, and glacial acetic acid is 6 g:15 mL:5 mL:0.6 mL;

[0039] S24, taking mercaptopropyl trimethoxysilane, anhydrous ethanol, deionized water and 25% ammonia water, heating and stirring in a water bath at 60°C for 3 hours, cooling to room temperature, adding the nano-titanium dioxide, stirring in a nitrogen atmosphere for 8 hours, centrifuging, washing the solid phase, and vacuum drying to obtain mercaptolated nano-titanium dioxide; the amount ratio of the mercaptopropyl trimethoxysilane, anhydrous ethanol, deionized water, ammonia water, and nano-titanium dioxide is 0.5g:60mL:10mL:1mL:2g;

[0040] S25. In a nitrogen atmosphere, castor oil and thiolated nano-titanium dioxide were mixed, stirred for 10 minutes, and irradiated with a UV lamp for 5 hours to perform a click chemistry reaction. The mixture was filtered, the solid phase was washed, and vacuum dried to obtain modified castor oil; the mass ratio of the castor oil to the thiolated nano-titanium dioxide was 10:25;

[0041] S26, taking the aminomethylated polyacrylamide solution and modified castor oil, mixing them, ultrasonically stirring for 20 minutes, adding 1 mol / L sodium hydroxide solution to adjust the pH to 9, heating and stirring in a 45°C water bath for 4 hours to obtain modified polyacrylamide; the molar ratio of the aminomethylated polyacrylamide to the modified castor oil is 1:1;

[0042] S26, coating the modified polyacrylamide on one side of the polypropylene film layer, and hot pressing at 65° C. for 2 hours to obtain a dielectric base layer with a uniform thickness of 3 μm;

[0043] S3, using metallic silver as an evaporation material to plate onto the side of the dielectric substrate containing modified polyacrylamide to form a metallized layer, thereby obtaining a metallized film for capacitors with a thickness of 5 μm; the evaporation refers to the process of depositing metal silver on a surface of the dielectric substrate in a vacuum of less than 1.2×10 -4 The deposition was carried out under the following conditions: 100 nm Pa, evaporation rate of 3 Å / s, evaporation current of 70 A, evaporation voltage of 1 V, and evaporation time of 25 s.

[0044] Example 2

[0045] A metallized film for capacitors and a preparation method thereof, comprising the following steps:

[0046] S1, preparing a polypropylene film layer;

[0047] 90 parts by weight of homopolymer polypropylene resin, 2 parts by weight of antioxidant, and 15 parts by weight of anhydrous ethanol were mixed and stirred for 35 minutes, filtered, and the solid phase was dried in an 80°C oven for 5.5 hours. The mixture was melt-blended and extruded into pellets using a twin-screw extruder, and then cast into a film using a multi-layer extruder. The film was then biaxially stretched to obtain a polypropylene film layer with a uniform thickness of 2 μm.

[0048] The antioxidant is any one of antioxidant 1076, antioxidant 1010, antioxidant 1024 and antioxidant 168;

[0049] The temperature conditions of the twin-screw extruder are: zone 1 150°C; zone 2 160°C; zone 3 180°C; zone 4 190°C; zones 5-8 200°C; zone 9 190°C; zone 10 185°C; zone 11 180°C; die head 175°C;

[0050] The casting process conditions are as follows: barrel zone temperature 160°C → 210°C → 230°C → 230°C; screen changing zone temperature 230°C → 215°C → 215°C → 215°C; distribution zone temperature 215°C → 210°C → 200°C → 200°C; die temperature 190°C; casting roller temperature 80°C; casting speed 1.0 m / min;

[0051] The stretching conditions are: stretching ratio 4×4; stretching rate 100% / s; preheating temperature 165° C.; preheating time 65 s; annealing temperature 80° C.;

[0052] The homopolymer polypropylene resin is selected from Lanzhou Petrochemical H9018;

[0053] S2. Prepare the dielectric base layer:

[0054] S21. In a nitrogen atmosphere, acrylamide, sodium formate, and deionized water were mixed, heated to 30°C and stirred for 15 minutes, ammonium persulfate was added, and stirred at 70°C for 2.5 hours. The mixture was poured into methanol, stirred for 2.5 minutes, filtered, and the solid phase was washed with methanol to obtain polyacrylamide; the mass ratio of acrylamide, sodium formate, deionized water, and ammonium persulfate was 10:0.015:200:0.01;

[0055] S22. Take a 40% formaldehyde aqueous solution, add a 33% dimethylamine aqueous solution, stir for 35 minutes, add a 2% polyacrylamide aqueous solution, and continue stirring for 4.5 hours to obtain an aminomethylated polyacrylamide solution; wherein the volume ratio of the formaldehyde aqueous solution, the dimethylamine aqueous solution, and the polyacrylamide aqueous solution is 7:0.3:1.5;

[0056] S23. Mix butyl titanate, anhydrous ethanol, and deionized water, stir for 8 minutes, add glacial acetic acid, stir for 25 minutes, vacuum dry at 120° C. for 10 hours, calcine at 250° C. for 1.5 hours, and grind to obtain nano-titanium dioxide; the ratio of butyl titanate, anhydrous ethanol, deionized water, and glacial acetic acid is 7 g:15 mL:5 mL:0.7 mL;

[0057] S24, taking mercaptopropyl trimethoxysilane, anhydrous ethanol, deionized water and 25% ammonia water, heating and stirring in a water bath at 60°C for 3.5 hours, cooling to room temperature, adding the nano-titanium dioxide, stirring in a nitrogen atmosphere for 9 hours, centrifuging, washing the solid phase, and vacuum drying to obtain mercaptolated nano-titanium dioxide; the amount ratio of the mercaptopropyl trimethoxysilane, anhydrous ethanol, deionized water, ammonia water, and nano-titanium dioxide is 0.55g:60mL:10mL:1mL:2.5g;

[0058] S25. In a nitrogen atmosphere, castor oil and thiolated nano-titanium dioxide were mixed, stirred for 15 minutes, and irradiated with a UV lamp for 6 hours to perform a click chemistry reaction. The mixture was filtered, the solid phase was washed, and vacuum dried to obtain modified castor oil; the mass ratio of the castor oil to the thiolated nano-titanium dioxide was 11:28;

[0059] S26, taking the aminomethylated polyacrylamide solution and modified castor oil, mixing them, ultrasonically stirring for 25 minutes, adding 1 mol / L sodium hydroxide solution to adjust the pH to 10, heating and stirring in a 50°C water bath for 5 hours to obtain modified polyacrylamide; the molar ratio of the aminomethylated polyacrylamide to the modified castor oil is 1:1;

[0060] S26, coating the modified polyacrylamide on one side of the polypropylene film layer, and hot pressing at 70° C. for 2.5 hours to obtain a dielectric base layer with a uniform thickness of 3 μm;

[0061] S3, using metallic silver as a vapor deposition material to deposit on the side of the dielectric substrate containing modified polyacrylamide to form a metallized layer, thereby obtaining a capacitor metallized film with a thickness of 10 μm; the vapor deposition refers to the process of depositing metal in a vacuum of less than 1.2×10 -4 The deposition was carried out under the following conditions: 1.5 Å Pa, evaporation rate 3.5 Å / s, evaporation current 75 A, evaporation voltage 2 V, and evaporation time 20 s.

[0062] Example 3

[0063] A metallized film for capacitors and a preparation method thereof, comprising the following steps:

[0064] S1, preparing a polypropylene film layer;

[0065] 92 parts by mass of homopolymer polypropylene resin, 3 parts by mass of antioxidant, and 20 parts by mass of anhydrous ethanol were mixed and stirred for 40 minutes, filtered, and the solid phase was dried in an 80°C oven for 6 hours. The mixture was melt-blended by a twin-screw extruder, extruded into pellets, and cast into a film by a multi-layer extruder. The film was then biaxially stretched to obtain a polypropylene film layer with a uniform thickness of 2 μm.

[0066] The antioxidant is any one of antioxidant 1076, antioxidant 1010, antioxidant 1024 and antioxidant 168;

[0067] The temperature conditions of the twin-screw extruder are: zone 1 150°C; zone 2 160°C; zone 3 180°C; zone 4 190°C; zones 5-8 200°C; zone 9 190°C; zone 10 185°C; zone 11 180°C; die head 175°C;

[0068] The casting process conditions are as follows: barrel zone temperature 160°C → 210°C → 230°C → 230°C; screen changing zone temperature 230°C → 215°C → 215°C → 215°C; distribution zone temperature 215°C → 210°C → 200°C → 200°C; die temperature 190°C; casting roller temperature 80°C; casting speed 1.0 m / min;

[0069] The stretching conditions are: stretching ratio 4×4; stretching rate 100% / s; preheating temperature 165° C.; preheating time 65 s; annealing temperature 80° C.;

[0070] The homopolymer polypropylene resin is selected from Lanzhou Petrochemical H9018;

[0071] S2. Prepare the dielectric base layer:

[0072] S21. In a nitrogen atmosphere, acrylamide, sodium formate, and deionized water were mixed, heated to 30°C and stirred for 20 minutes, ammonium persulfate was added, and stirred at 75°C for 3 hours. The mixture was poured into methanol, stirred for 3 minutes, filtered, and the solid phase was washed with methanol to obtain polyacrylamide; the mass ratio of acrylamide, sodium formate, deionized water, and ammonium persulfate was 12:0.02:200:0.012;

[0073] S22, taking a 40% formaldehyde aqueous solution, adding a 33% dimethylamine aqueous solution by mass, stirring for 40 minutes, adding a 2% polyacrylamide aqueous solution by mass, and continuing to stir for 5 hours to obtain an aminomethylated polyacrylamide solution; wherein the volume ratio of the formaldehyde aqueous solution, the dimethylamine aqueous solution, and the polyacrylamide aqueous solution is 8:0.4:2;

[0074] S23. Mix butyl titanate, anhydrous ethanol, and deionized water, stir for 10 minutes, add glacial acetic acid, stir for 30 minutes, vacuum dry at 120° C. for 10 hours, calcine at 250° C. for 2 hours, and grind to obtain nano-titanium dioxide; the ratio of butyl titanate, anhydrous ethanol, deionized water, and glacial acetic acid is 8 g:15 mL:5 mL:0.8 mL;

[0075] S24, taking mercaptopropyl trimethoxysilane, anhydrous ethanol, deionized water and 25% ammonia water, heating and stirring in a water bath at 60°C for 4 hours, cooling to room temperature, adding the nano-titanium dioxide, stirring in a nitrogen atmosphere for 10 hours, centrifuging, washing the solid phase, and vacuum drying to obtain mercaptolated nano-titanium dioxide; the amount ratio of the mercaptopropyl trimethoxysilane, anhydrous ethanol, deionized water, ammonia water, and nano-titanium dioxide is 0.6g:60mL:10mL:1mL:3g;

[0076] S25. In a nitrogen atmosphere, castor oil and thiolated nano-titanium dioxide were mixed, stirred for 20 minutes, and irradiated with a UV lamp for 7 hours to perform a click chemistry reaction. The mixture was filtered, the solid phase was washed, and vacuum dried to obtain modified castor oil; the mass ratio of the castor oil to the thiolated nano-titanium dioxide was 12:30;

[0077] S26, taking the aminomethylated polyacrylamide solution and modified castor oil, mixing them, ultrasonically stirring for 30 minutes, adding 1 mol / L sodium hydroxide solution to adjust the pH to 11, heating and stirring in a 55° C. water bath for 6 hours to obtain modified polyacrylamide; the molar ratio of the aminomethylated polyacrylamide to the modified castor oil is 1:1;

[0078] S26, coating the modified polyacrylamide on one side of the polypropylene film layer, and hot pressing at 75° C. for 3 hours to obtain a dielectric base layer with a uniform thickness of 3 μm;

[0079] S3, using metallic silver as a vapor deposition material to deposit on the side of the dielectric substrate containing modified polyacrylamide to form a metallized layer, thereby obtaining a capacitor metallized film with a thickness of 10 μm; the vapor deposition refers to the process of depositing metal in a vacuum of less than 1.2×10 -4 The deposition was carried out under the following conditions: 1.5 Å Pa, evaporation rate 4 Å / s, evaporation current 80 A, evaporation voltage 3 V, and evaporation time 15 s.

[0080] Comparative Example 1

[0081] The difference from Example 2 is that the preparation process of the dielectric base layer is eliminated, and metallic silver is directly evaporated onto the polypropylene film layer to form a metallized film.

[0082] Comparative Example 2

[0083] The difference from Example 2 is that the method for preparing the dielectric base layer includes the following steps:

[0084] A polyacrylamide aqueous solution with a mass fraction of 2% was prepared, nano-titanium dioxide was added, ultrasonic stirring was performed for 25 minutes, and the solution was coated on one side of the polypropylene film layer. The solution was hot-pressed at 70° C. for 2.5 hours to obtain a dielectric base layer.

[0085] Comparative Example 3

[0086] The difference from Example 2 is that the preparation process of the dielectric base layer includes the following steps:

[0087] S21. In a nitrogen atmosphere, acrylamide, sodium formate, and deionized water were mixed, heated to 30°C and stirred for 15 minutes, ammonium persulfate was added, and stirred at 70°C for 2.5 hours. The mixture was poured into methanol, stirred for 2.5 minutes, filtered, and the solid phase was washed with methanol to obtain polyacrylamide; the mass ratio of acrylamide, sodium formate, deionized water, and ammonium persulfate was 10:0.015:200:0.01;

[0088] S22. Take a 40% formaldehyde aqueous solution, add a 33% dimethylamine aqueous solution, stir for 35 minutes, add a 2% polyacrylamide aqueous solution, and continue stirring for 4.5 hours to obtain an aminomethylated polyacrylamide solution; wherein the volume ratio of the formaldehyde aqueous solution, the dimethylamine aqueous solution, and the polyacrylamide aqueous solution is 7:0.3:1.5;

[0089] S23. Mix butyl titanate, anhydrous ethanol, and deionized water, stir for 8 minutes, add glacial acetic acid, stir for 25 minutes, vacuum dry at 120° C. for 10 hours, calcine at 250° C. for 1.5 hours, and grind to obtain nano-titanium dioxide; the ratio of butyl titanate, anhydrous ethanol, deionized water, and glacial acetic acid is 7 g:15 mL:5 mL:0.7 mL;

[0090] S24, taking the aminomethylated polyacrylamide solution and nano-titanium dioxide, mixing them, ultrasonically stirring for 25 minutes, adding 1 mol / L sodium hydroxide solution to adjust the pH to 10, heating and stirring in a 50°C water bath for 5 hours to obtain nano-titanium dioxide-doped polyacrylamide; the molar ratio of the aminomethylated polyacrylamide to the nano-titanium dioxide is 1:1;

[0091] S26, coating the modified polyacrylamide on one side of the polypropylene film layer, and hot pressing at 70° C. for 2.5 hours to obtain a dielectric base layer.

[0092] Comparative Example 4

[0093] The difference from Example 2 is that the preparation process of the dielectric base layer includes the following steps:

[0094] S21. Mix butyl titanate, anhydrous ethanol, and deionized water, stir for 8 minutes, add glacial acetic acid, stir for 25 minutes, vacuum dry at 120°C for 10 hours, calcine at 250°C for 1.5 hours, and grind to obtain nano-titanium dioxide; the ratio of butyl titanate, anhydrous ethanol, deionized water, and glacial acetic acid is 7 g:15 mL:5 mL:0.7 mL;

[0095] S22, taking mercaptopropyl trimethoxysilane, anhydrous ethanol, deionized water and 25% ammonia water, heating and stirring in a water bath at 60°C for 3.5 hours, cooling to room temperature, adding the nano-titanium dioxide, stirring in a nitrogen atmosphere for 9 hours, centrifuging, washing the solid phase, and vacuum drying to obtain mercaptolated nano-titanium dioxide; the amount ratio of the mercaptopropyl trimethoxysilane, anhydrous ethanol, deionized water, ammonia water, and nano-titanium dioxide is 0.55g:60mL:10mL:1mL:2.5g;

[0096] S23. In a nitrogen atmosphere, castor oil and thiolated nano-titanium dioxide were mixed, stirred for 15 minutes, and irradiated with a UV lamp for 6 hours to perform a click chemistry reaction. The mixture was filtered, the solid phase was washed, and vacuum dried to obtain modified castor oil; the mass ratio of the castor oil to the thiolated nano-titanium dioxide was 11:28;

[0097] S24, mixing a 2% by mass aqueous solution of polyacrylamide and modified castor oil, stirring them ultrasonically for 25 minutes, adding 1 mol / L sodium hydroxide solution to adjust the pH to 10, heating and stirring in a 50° C. water bath for 5 hours to obtain modified castor oil-doped polyacrylamide; the molar ratio of the polyacrylamide to the modified castor oil is 1:1;

[0098] S25, coating the modified polyacrylamide on one side of the polypropylene film layer, and hot pressing at 70° C. for 2.5 hours to obtain a dielectric base layer.

[0099] Performance Testing

[0100] 1) The metallized films obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were subjected to a square resistance test. The test results are shown in Table 1 below.

[0101] 2) The dielectric strength of the metallized films obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was tested. The test results are shown in Table 1 below.

[0102] 3) The metal layer adhesion test was performed on the metallized films obtained in Examples 1 to 3 and Comparative Examples 1 to 4 to observe whether the metal coating had obvious peeling. The test results are shown in Table 1 below.

[0103] Table 1

[0104]

[0105] As can be seen from Table 1, the metallized films prepared in Examples 1 to 3 of the present application have good anti-peeling properties, ensure the stability of the component structure, high dielectric strength and low square resistance, and reduce power transmission loss; in Comparative Example 1, castor oil-modified polyacrylamide containing titanium dioxide was not added, resulting in a significant decrease in the performance of the metallized film; in Comparative Examples 2-4, only the physical mixing of polyimide and nano-titanium dioxide was relied upon, resulting in a decrease in the performance of the metallized film.

[0106] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a metallized film for a capacitor, characterized in that: The following steps are involved: S1, preparing a polypropylene film layer; S2. Prepare the dielectric base layer: S21, preparing polyacrylamide; S22, preparing aminomethylated polyacrylamide using formaldehyde, dimethylamine and polyacrylamide as raw materials; S23, preparing nano titanium dioxide; S24, preparing mercaptolated nano-titanium dioxide using mercaptopropyltrimethoxysilane and nano-titanium dioxide as raw materials; S25, performing a click chemistry reaction using castor oil and thiol-modified nano-titanium dioxide to obtain modified castor oil; S26, preparing modified polyacrylamide using aminomethylated polyacrylamide solution and modified castor oil as raw materials; S26, coating the modified polyacrylamide on one side of the polypropylene film layer, and hot pressing at 65-75° C. for 2-3 hours to obtain a dielectric base layer; S3. Using a metal material as a vapor deposition material, plating the metal material onto the side of the dielectric substrate containing the modified polyacrylamide to form a metallization layer, thereby obtaining the metallization film for the capacitor.

2. The method for preparing a metallized film for capacitors according to claim 1, wherein: In step S3, the metal material is selected from any one of Ag, Al, Cu, Au, Ni, and Ge.

3. The method for preparing a metallized film for capacitors according to claim 1, wherein: In step S3, the vacuum degree of the evaporation process is less than 1.2×10 -4 Pa.

4. The method for preparing a metallized film for capacitors according to claim 1, wherein: In step S3, the evaporation rate of the evaporation process is 3-4 Å / s.

5. The method for preparing a metallized film for capacitors according to claim 1, wherein: In step S3, the evaporation current of the evaporation process is 70-80A.

6. The method for preparing a metallized film for capacitors according to claim 1, wherein: In step S3, the evaporation voltage of the evaporation process is 1-3V.

7. The method for preparing a metallized film for capacitors according to claim 1, wherein: In step S3, the evaporation time of the evaporation process is 15-25 seconds.

8. A metallized film for capacitors prepared according to the preparation method according to any one of claims 1 to 7.

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