High-temperature-resistant capacitor film and capacitor

Abstract

The invention discloses a high-temperature-resistant capacitor film and a capacitor, and belongs to the technical field of capacitors, and the high-temperature-resistant capacitor film is prepared from the following raw materials in parts by weight: 55-75 parts of polycarbonate, 4-6 parts of functional filler, 0.1-0.5 part of citrate and 4-5 parts of zinc stearate. The preparation method comprises the following steps: uniformly mixing the raw materials, melting at 170-190 DEG C, filtering, exhausting for 10-12 times, carrying out hot press molding to form a thick sheet, and stretching to prepare the thin film. When the functional filler is blended with polycarbonate, a special hollow structure of modified silicon dioxide can prevent free movement of plastic molecules by forming a physical cross-linked structure, so that the high temperature resistance of a matrix is improved, and an introduced intermediate structure can endow the matrix with voltage resistance, so that the high temperature resistance of the matrix is improved. Therefore, the prepared film has excellent heat resistance and voltage resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitors, and in particular to a high temperature resistant capacitor film and a capacitor. Background Art

[0002] Film capacitors use metal foil as electrodes, which are overlapped with plastic films such as polyethylene, polypropylene, polystyrene or polycarbonate at both ends and then wound into a cylindrical structure. Among all plastic film capacitors, polypropylene capacitors and polystyrene capacitors have the most significant characteristics. Capacitors made of polypropylene film have significant advantages such as low heat shrinkage, stable performance, high temperature resistance, high voltage resistance, and prevention of breakdown, making the use of capacitors made of polypropylene film increasingly wide.

[0003] When film capacitors are used under high-frequency or high-pulse conditions, the pulse current passing through the capacitor will cause the capacitor itself to heat up and the temperature will rise, leading to problems such as increased self-healing point, reduced withstand voltage, and shortened life. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a high temperature resistant capacitor film and a capacitor.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A high temperature resistant capacitor film comprises the following raw materials in parts by weight: 55-75 parts of polycarbonate, 4-6 parts of functional filler, 0.1-0.5 parts of citrate, and 4-5 parts of zinc stearate; The functional filler is prepared by the following steps: Step S1, adding polyvinyl pyrrolidone to deionized water, stirring evenly and then introducing nitrogen, adding styrene at room temperature, heating to 60-70° C., adding ammonium persulfate, keeping warm and reacting for 24 hours, filtering, washing and drying after the reaction to obtain template microspheres; Step S2, adding the prepared template microspheres into deionized water, stirring evenly, adding anhydrous ethanol, then dropping 10% ammonia water by mass, heating to 70° C., adding tetraethyl orthosilicate, keeping warm and reacting for 12 hours, centrifuging, filtering, washing, and drying after the reaction is completed to obtain hollow silica microspheres; In step S1-step S2, ammonium persulfate is used as an initiator and polyvinyl pyrrolidone is used as a dispersant to first introduce styrene polymerization to prepare a polystyrene template, and then under the catalysis of ammonia water, tetraethyl orthosilicate is hydrolyzed and condensed to form hollow silica microspheres.

[0006] Step S3, adding the hollow silica microspheres to a 10% by volume ethanol aqueous solution, adding KH550, heating to 40-45° C., stirring at a uniform speed and reacting for 1-2 hours, and obtaining modified silica after the reaction is completed; In step S3, the surface of the hollow silica microspheres is modified by using a silane coupling agent KH550, and amino groups are introduced on the surface of the silica to prepare modified silica.

[0007] Step S4, adding maleic anhydride and 2,4-dihydroxybenzophenone into tetrahydrofuran, introducing nitrogen, adding concentrated sulfuric acid dropwise, raising the temperature to 70-75° C., keeping the temperature and reacting for 10 hours to obtain an intermediate; In step S4, concentrated sulfuric acid is used as a catalyst to react maleic anhydride and 2,4-dihydroxybenzophenone to obtain an intermediate, which can be used as a voltage stabilizer; Step S5, adding the prepared modified silica to N,N-dimethylformamide, adding the intermediate, heating to 40-45° C., adding pyridine, stirring at a uniform speed and reacting for 4-6 hours to prepare a functional filler.

[0008] In step S5, under the catalytic action of base, the amino group on the modified silica reacts with the carbon-carbon double bond on the intermediate, and then the intermediate structure is connected to the surface of the modified silica to obtain a functional filler.

[0009] Furthermore, in step S1, the dosage ratio of polyvinyl pyrrolidone, ammonium persulfate, styrene and deionized water is controlled to be 1.2-1.5 g: 0.2-0.25 g: 10-12 g: 100 mL.

[0010] Furthermore, in step S2, the dosage ratio of the template microspheres, ammonia water, tetraethyl orthosilicate and anhydrous ethanol is controlled to be 1-1.2 g: 0.1-0.2 mL: 3-5 mL: 10-15 mL.

[0011] Furthermore, in step S3, the dosage ratio of the hollow silica microspheres, KH550 and the ethanol aqueous solution is controlled to be 1-1.2 g: 0.5-0.8 g: 10 mL.

[0012] Furthermore, in step S4, the dosage ratio of maleic anhydride, 2,4-dihydroxybenzophenone, concentrated sulfuric acid and tetrahydrofuran is controlled to be 1-2 g: 2-3 g: 0.5-0.8 mL: 50 mL.

[0013] Furthermore, in step S5, the weight ratio of the modified silica, the intermediate and N,N-dimethylformamide is controlled to be 1-1.2 g: 0.2-0.5 g: 20-30 mL, and the amount of pyridine used is 5-8% of the weight of the intermediate.

[0014] Furthermore, the high temperature resistant capacitor film is made by the following steps: mixing the raw materials uniformly, melting at 170-190° C., filtering, exhausting 10-12 times, hot pressing to form a thick sheet, stretching, and making a film.

[0015] A capacitor comprises the above-mentioned high temperature resistant capacitor film.

[0016] Beneficial effects of the present invention: The invention prepares a high-temperature resistant capacitor film. Polycarbonate is used as a raw material to prepare a modified silicon dioxide. Then concentrated sulfuric acid is used as a catalyst to react maleic anhydride and 2,4-dihydroxybenzophenone to obtain an intermediate. The intermediate can be used as a voltage stabilizer. Under the catalytic action of alkali, the amino group on the modified silicon dioxide reacts with the carbon-carbon double bond on the intermediate. Then the intermediate structure is connected to the surface of the modified silicon dioxide to obtain a functional filler. When the functional filler is blended with polycarbonate, the special hollow structure of the modified silicon dioxide can prevent the free movement of plastic molecules by forming a physical cross-linking structure, thereby improving the high-temperature resistance of the substrate. The introduced intermediate structure can give the substrate voltage resistance, so that the prepared film has both excellent heat resistance and voltage resistance. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0018] Example 1: A high temperature resistant capacitor film, comprising the following raw materials in parts by weight: 55 parts of polycarbonate, 4 parts of functional filler, 0.1 parts of citrate, and 4 parts of zinc stearate; The functional filler is prepared by the following steps: Step S1, adding polyvinyl pyrrolidone to deionized water, stirring evenly and then introducing nitrogen, adding styrene at room temperature, heating to 60°C, adding ammonium persulfate, keeping warm and reacting for 24 hours, filtering, washing and drying after the reaction to obtain template microspheres, and controlling the dosage ratio of polyvinyl pyrrolidone, ammonium persulfate, styrene and deionized water to be 1.2g:0.2g:10g:100mL; Step S2, adding the prepared template microspheres into deionized water, stirring evenly, adding anhydrous ethanol, then dropping 10% ammonia water by mass, heating to 70°C, adding tetraethyl orthosilicate, keeping warm and reacting for 12 hours, centrifuging, filtering, washing and drying after the reaction to obtain hollow silica microspheres, and controlling the usage ratio of template microspheres, ammonia water, tetraethyl orthosilicate and anhydrous ethanol to be 1 g: 0.1 mL: 3 mL: 10 mL; Step S3, adding hollow silica microspheres to a 10% volume fraction ethanol aqueous solution, adding KH550, heating to 40°C, stirring at a uniform speed and reacting for 1 hour, and obtaining modified silica after the reaction is completed, wherein the amount ratio of hollow silica microspheres, KH550 and ethanol aqueous solution is controlled to be 1 g:0.5 g:10 mL; Step S4, adding maleic anhydride and 2,4-dihydroxybenzophenone to tetrahydrofuran, introducing nitrogen, adding concentrated sulfuric acid dropwise, raising the temperature to 70°C, keeping the temperature and reacting for 10 hours to obtain an intermediate, wherein the amount ratio of maleic anhydride, 2,4-dihydroxybenzophenone, concentrated sulfuric acid and tetrahydrofuran is controlled to be 1g:2g:0.5mL:50mL; Step S5, adding the prepared modified silica to N,N-dimethylformamide, adding the intermediate, heating to 40°C, adding pyridine, stirring at a uniform speed and reacting for 4 hours to obtain a functional filler, controlling the weight ratio of the modified silica, the intermediate and N,N-dimethylformamide to be 1g:0.2g:20mL, and the amount of pyridine to be 5% of the weight of the intermediate.

[0019] The high temperature resistant capacitor film is made by the following steps: mixing the raw materials uniformly, melting at 170-190° C., filtering, exhausting 10 times, hot pressing to form a thick sheet, stretching, and making a film.

[0020] A capacitor comprises the above-mentioned high temperature resistant capacitor film.

[0021] Example 2: A high temperature resistant capacitor film, comprising the following raw materials in parts by weight: 70 parts of polycarbonate, 5 parts of functional filler, 0.3 parts of citrate, and 5 parts of zinc stearate; The functional filler is prepared by the following steps: Step S1, adding polyvinyl pyrrolidone to deionized water, stirring evenly and then introducing nitrogen, adding styrene at room temperature, heating to 65°C, adding ammonium persulfate, keeping warm and reacting for 24 hours, filtering, washing and drying after the reaction to obtain template microspheres, and controlling the dosage ratio of polyvinyl pyrrolidone, ammonium persulfate, styrene and deionized water to be 1.4g:0.22g:10g:100mL; Step S2, adding the prepared template microspheres into deionized water, stirring evenly, adding anhydrous ethanol, then dropping 10% ammonia water by mass, heating to 70°C, adding tetraethyl orthosilicate, keeping warm and reacting for 12 hours, centrifuging, filtering, washing and drying after the reaction to obtain hollow silica microspheres, and controlling the usage ratio of template microspheres, ammonia water, tetraethyl orthosilicate and anhydrous ethanol to be 1.1 g: 0.1 mL: 4 mL: 14 mL; Step S3, adding the hollow silica microspheres to a 10% volume fraction ethanol aqueous solution, adding KH550, heating to 42°C, stirring at a uniform speed and reacting for 1.5 hours, and obtaining modified silica after the reaction, wherein the amount ratio of the hollow silica microspheres, KH550 and the ethanol aqueous solution is controlled to be 1.1 g:0.6 g:10 mL; Step S4, adding maleic anhydride and 2,4-dihydroxybenzophenone to tetrahydrofuran, introducing nitrogen, adding concentrated sulfuric acid dropwise, raising the temperature to 74°C, keeping the temperature and reacting for 10 hours to obtain an intermediate, wherein the amount ratio of maleic anhydride, 2,4-dihydroxybenzophenone, concentrated sulfuric acid and tetrahydrofuran is controlled to be 1.5 g: 2.5 g: 0.6 mL: 50 mL; Step S5, adding the prepared modified silica to N,N-dimethylformamide, adding the intermediate, heating to 44°C, adding pyridine, stirring at a uniform speed and reacting for 5 hours to obtain a functional filler, controlling the weight ratio of the modified silica, the intermediate and N,N-dimethylformamide to be 1.1 g:0.4 g:25 mL, and the amount of pyridine to be 6% of the weight of the intermediate.

[0022] The high temperature resistant capacitor film is made by the following steps: mixing the raw materials uniformly, melting at 180° C., filtering, exhausting 12 times, hot pressing to form a thick sheet, stretching, and making a film.

[0023] A capacitor comprises the above-mentioned high temperature resistant capacitor film.

[0024] Example 3: A high temperature resistant capacitor film, comprising the following raw materials in parts by weight: 75 parts of polycarbonate, 6 parts of functional filler, 0.5 parts of citrate, and 5 parts of zinc stearate; The functional filler is prepared by the following steps: Step S1, adding polyvinyl pyrrolidone to deionized water, stirring evenly and then introducing nitrogen, adding styrene at room temperature, heating to 70°C, adding ammonium persulfate, keeping warm and reacting for 24 hours, filtering, washing and drying after the reaction to obtain template microspheres, and controlling the dosage ratio of polyvinyl pyrrolidone, ammonium persulfate, styrene and deionized water to be 1.5g:0.25g:12g:100mL; Step S2, adding the prepared template microspheres into deionized water, stirring evenly, adding anhydrous ethanol, then dropping 10% ammonia water by mass, heating to 70°C, adding tetraethyl orthosilicate, keeping warm and reacting for 12 hours, centrifuging, filtering, washing and drying after the reaction to obtain hollow silica microspheres, and controlling the usage ratio of template microspheres, ammonia water, tetraethyl orthosilicate and anhydrous ethanol to be 1.2 g: 0.2 mL: 5 mL: 15 mL; Step S3, adding the hollow silica microspheres to a 10% volume fraction ethanol aqueous solution, adding KH550, heating to 45°C, stirring at a constant speed and reacting for 2 hours, and obtaining modified silica after the reaction is completed, wherein the amount ratio of the hollow silica microspheres, KH550 and the ethanol aqueous solution is controlled to be 1.2 g:0.8 g:10 mL; Step S4, adding maleic anhydride and 2,4-dihydroxybenzophenone to tetrahydrofuran, introducing nitrogen, adding concentrated sulfuric acid dropwise, raising the temperature to 75°C, keeping the temperature and reacting for 10 hours to obtain an intermediate, wherein the amount ratio of maleic anhydride, 2,4-dihydroxybenzophenone, concentrated sulfuric acid and tetrahydrofuran is controlled to be 2g:3g:0.8mL:50mL; Step S5, adding the prepared modified silica to N,N-dimethylformamide, adding the intermediate, heating to 45°C, adding pyridine, stirring at a uniform speed and reacting for 6 hours to obtain a functional filler, controlling the weight ratio of the modified silica, the intermediate and N,N-dimethylformamide to be 1.2g:0.5g:30mL, and the amount of pyridine to be 8% of the weight of the intermediate.

[0025] The high temperature resistant capacitor film is made by the following steps: mixing the raw materials uniformly, melting at 190° C., filtering, exhausting 12 times, hot pressing to form a thick sheet, stretching, and making a film.

[0026] A capacitor comprises the above-mentioned high temperature resistant capacitor film.

[0027] Comparative Example 1: Compared with Example 1, this comparative example uses nano-silicon dioxide instead of functional filler, and the rest is the same as Example 1.

[0028] The performance of the capacitor films prepared in Examples 1-3 and Comparative Example 1 was tested, and the results are shown in Table 1 below: The heat shrinkage is measured after heating at 120°C for 15 min; The test method for withstand voltage value is carried out in accordance with the standard IEC60243-1-1998.

[0029] Table 1 It can be seen from Table 1 above that the capacitor films prepared in Examples 1 to 3 of the present invention have excellent heat resistance and good voltage resistance performance.

[0030] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A high temperature resistant capacitor film, characterized in that: The invention comprises the following raw materials in parts by weight: 55-75 parts of polycarbonate, 4-6 parts of functional filler, 0.1-0.5 parts of citrate, and 4-5 parts of zinc stearate; The functional filler is prepared by the following steps: Step S1, adding polyvinyl pyrrolidone to deionized water, stirring evenly and then introducing nitrogen, adding styrene at room temperature, heating to 60-70° C., adding ammonium persulfate, keeping warm and reacting for 24 hours, filtering, washing and drying after the reaction to obtain template microspheres; Step S2, adding the prepared template microspheres into deionized water, stirring evenly, adding anhydrous ethanol, then dropping 10% ammonia water by mass, heating to 70° C., adding tetraethyl orthosilicate, keeping warm and reacting for 12 hours, centrifuging, filtering, washing, and drying after the reaction is completed to obtain hollow silica microspheres; Step S3, adding the hollow silica microspheres to a 10% by volume ethanol aqueous solution, adding KH550, heating to 40-45° C., stirring at a uniform speed and reacting for 1-2 hours, and obtaining modified silica after the reaction is completed; Step S4, adding maleic anhydride and 2,4-dihydroxybenzophenone into tetrahydrofuran, introducing nitrogen, adding concentrated sulfuric acid dropwise, raising the temperature to 70-75° C., keeping the temperature and reacting for 10 hours to obtain an intermediate; Step S5, adding the prepared modified silica to N,N-dimethylformamide, adding the intermediate, heating to 40-45° C., adding pyridine, stirring at a uniform speed and reacting for 4-6 hours to prepare a functional filler.

2. The high temperature resistant capacitor film according to claim 1, characterized in that: In step S1, the dosage ratio of polyvinyl pyrrolidone, ammonium persulfate, styrene and deionized water is controlled to be 1.2-1.5 g: 0.2-0.25 g: 10-12 g: 100 mL.

3. The high temperature resistant capacitor film according to claim 1, characterized in that: In step S2, the dosage ratio of the template microspheres, ammonia water, tetraethyl orthosilicate and anhydrous ethanol is controlled to be 1-1.2 g: 0.1-0.2 mL: 3-5 mL: 10-15 mL.

4. The high temperature resistant capacitor film according to claim 1, characterized in that: In step S3, the dosage ratio of hollow silica microspheres, KH550 and ethanol aqueous solution is controlled to be 1-1.2 g: 0.5-0.8 g: 10 mL.

5. The high temperature resistant capacitor film according to claim 1, characterized in that: In step S4, the dosage ratio of maleic anhydride, 2,4-dihydroxybenzophenone, concentrated sulfuric acid and tetrahydrofuran is controlled to be 1-2 g: 2-3 g: 0.5-0.8 mL: 50 mL.

6. The high temperature resistant capacitor film according to claim 1, characterized in that: In step S5, the weight ratio of the modified silica, the intermediate and N,N-dimethylformamide is controlled to be 1-1.2 g: 0.2-0.5 g: 20-30 mL, and the amount of pyridine used is 5-8% of the weight of the intermediate.

7. The high temperature resistant capacitor film according to claim 1, characterized in that: The method is prepared by the following steps: uniformly mixing the raw materials, melting at 170-190° C., filtering, exhausting 10-12 times, hot pressing to form a thick sheet, and stretching to form a film.

8. A capacitor, characterized in that: The invention comprises the high temperature resistant capacitor film as described in any one of claims 1 to 7.

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