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CN-122011594-A - Biaxially oriented polypropylene-based capacitor film and preparation method thereof

CN122011594ACN 122011594 ACN122011594 ACN 122011594ACN-122011594-A

Abstract

The scheme relates to the technical field of capacitance films, and discloses a biaxially oriented polypropylene-based capacitance film and a preparation method thereof, wherein the capacitance film is prepared from polypropylene resin, a filler, a compatilizer, a nucleating agent and an antioxidant, wherein the compatilizer is prepared by melt extrusion granulation of maleic anhydride grafted polypropylene and BN@SiO 2 -NH 2 , and the BN@SiO 2 -NH 2 is prepared by mixing boron nitride and urea in a ball mill, mechanically stripping, then dispersing the mixture in an ethanol aqueous solution in an ultrasonic manner, adding tetraethoxysilane and ammonia water, stirring and hydrolyzing the mixture to prepare BN@SiO 2 , and finally carrying out reflux grafting on the BN@SiO 2 -NH 2 with gamma-aminopropyl triethoxysilane. The compatilizer formed by premixing MAH-g-PP and BN@SiO 2 -NH 2 can be uniformly dispersed, so that agglomeration is avoided, and the compatilizer also contains BN and SiO 2 , plays roles of enhancing an interface, improving breakdown strength and the like as a filler, promotes the dispersion of inorganic particles, and effectively improves the dielectric constant.

Inventors

  • WANG FENG
  • WANG RUNXIAO
  • ZHUANG ZHI
  • WANG YONGJUN
  • WANG JINZE

Assignees

  • 扬州博恒新能源材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260415

Claims (7)

  1. 1. The biaxially oriented polypropylene-based capacitor film is characterized by comprising, by weight, 100 parts of polypropylene resin, 3-8 parts of filler, 5-10 parts of compatilizer, 0.1-0.5 part of nucleating agent and 0.1-0.5 part of antioxidant; The compatilizer is prepared by melt extrusion granulation of maleic anhydride grafted polypropylene and BN@SiO 2 -NH 2 , and the preparation process of the BN@SiO 2 -NH 2 is as follows: Mixing boron nitride and urea, placing the mixture into a ball mill, performing ball milling for 10-20 hours, performing mechanical stripping, then dispersing the mixture into an ethanol water solution by ultrasonic, adding tetraethoxysilane and ammonia water, stirring and hydrolyzing to obtain BN@Si 2 , and finally performing reflux grafting with gamma-aminopropyl triethoxysilane to obtain BN@SiO 2 -NH 2 .
  2. 2. The biaxially oriented polypropylene base capacitor film according to claim 1, wherein the mass ratio of maleic anhydride grafted polypropylene to BN@SiO 2 -NH 2 in the compatilizer is 100:20-30, and the preparation process comprises the steps of mixing maleic anhydride grafted polypropylene and BN@SiO 2 -NH 2 , putting into a twin-screw extruder, and carrying out melt extrusion granulation at 180-220 ℃ to obtain compatilizer granules.
  3. 3. The biaxially oriented polypropylene based capacitor film according to claim 1, wherein the grafting ratio of the maleic anhydride grafted polypropylene is 1.2% -1.5%.
  4. 4. The biaxially oriented polypropylene based capacitor film according to claim 1, wherein the bn@sio 2 -NH 2 is prepared as follows: 1) Mixing boron nitride and urea according to a mass ratio of 1:20-40, placing the mixture in a ball mill, wherein a ball material ratio is 80:1-120:1, a rotating speed is 400-600 r/min, and performing mechanical stripping after ball milling for 15-20 hours to obtain stripped boron nitride which is recorded as BN; 2) Ultrasonically dispersing BN in an ethanol water solution, regulating the pH to 8-9 by using dilute ammonia water, slowly dripping tetraethoxysilane into the BN dispersion, stirring for 6 hours at 40 ℃, and centrifugally washing to obtain BN@SiO 2 ; 3) And dispersing BN@SiO 2 in ethanol, and adding 30-50% of gamma-aminopropyl triethoxysilane by mass of BN@SiO 2 to perform reflux grafting to obtain BN@SiO 2 -NH 2 .
  5. 5. The biaxially oriented polypropylene based capacitor film according to claim 1, wherein the filler is one or more selected from the group consisting of aluminum oxide, calcium carbonate, titanium dioxide and barium titanate.
  6. 6. The biaxially oriented polypropylene base capacitor film according to claim 1, wherein the nucleating agent is talc powder having a particle diameter of 100-200nm, and the antioxidant is antioxidant 1010 or antioxidant 168.
  7. 7. The method for producing a biaxially oriented polypropylene based capacitor film according to any one of claims 1 to 6, comprising the steps of: S1, drying polypropylene resin, mixing the polypropylene resin with a filler, a compatilizer, a nucleating agent and an antioxidant, stirring in a high-speed mixer, feeding the mixture into a double-screw extruder, carrying out melt extrusion at 210-230 ℃, and casting a cast sheet; S2, performing biaxial stretching on the cast sheet, preheating to 70-90 ℃, performing longitudinal stretching at 110-130 ℃ with a stretching multiplying power of 4-5 times, and performing transverse stretching at 120-150 ℃ with a stretching multiplying power of 5-6 times; And S3, performing heat setting on the biaxially stretched film, cooling at 50 ℃, performing corona treatment, traction and winding to obtain the film.

Description

Biaxially oriented polypropylene-based capacitor film and preparation method thereof Technical Field The invention relates to the technical field of capacitance films, in particular to a biaxially oriented polypropylene-based capacitance film and a preparation method thereof. Background The polypropylene (PP) film has the advantages of low density, good chemical corrosion resistance, low cost and the like, and is widely applied to the fields of food packaging, medical packaging, production and conveying pipelines, textiles, electronic components and the like. The capacitor is one of three passive components, and has a figure in various electronic products. The thin film capacitor is widely applied to new energy fields such as new energy automobiles, photovoltaic and wind power generation due to the characteristics of high pressure resistance, temperature resistance, stability and the like. With the continuous progress and rapid development of technology, the performance requirement of the thin film capacitor is also higher and higher, and the performance of the capacitor device is optimized and improved by improving the performance of the capacitor film material as the core material of the thin film capacitor, which is one of the main attack directions in the field at present. Biaxially oriented polypropylene film (BOPP) is the most successful commercial polymer dielectric material at present, which has high breakdown strength, excellent temperature stability, relatively low cost and processability suitable for large-scale automated production. While BOPP films offer significant advantages, their physical properties also limit their application in some high-end scenarios, in which BOPP performs well at low temperatures, its breakdown field strength is rapidly reduced and dielectric loss is significantly increased in high temperature (> 70 ℃) environments. In addition, the difficulty of increasing the dielectric constant is great, and the dielectric constant is often increased to sacrifice the insulation strength and the temperature resistance. Disclosure of Invention Aiming at the defects in the prior art, the invention designs a compatilizer which can be used as a filler and can assist inorganic particles to disperse in a matrix, so that the dielectric constant is effectively improved, and the heat resistance and the breakdown strength of the compatilizer are improved. In order to achieve the above purpose, the present invention provides the following technical solutions: The biaxially oriented polypropylene-based capacitor film comprises, by weight, 100 parts of polypropylene resin, 3-8 parts of filler, 5-10 parts of compatilizer, 0.1-0.5 part of nucleating agent and 0.1-0.5 part of antioxidant; The compatilizer is prepared by melt extrusion granulation of maleic anhydride grafted polypropylene and BN@SiO 2-NH2, and the preparation process of the BN@SiO 2-NH2 is as follows: Mixing boron nitride and urea, placing the mixture into a ball mill, performing ball milling for 10-20 hours, performing mechanical stripping, then dispersing the mixture into an ethanol water solution by ultrasonic, adding tetraethoxysilane and ammonia water, stirring and hydrolyzing to obtain BN@Si 2, and finally performing reflux grafting with gamma-aminopropyl triethoxysilane to obtain BN@SiO 2-NH2. Further, the mass ratio of the maleic anhydride grafted polypropylene to the BN@SiO 2-NH2 in the compatilizer is 100:20-30, and the specific preparation process comprises the steps of mixing the maleic anhydride grafted polypropylene (MAH-g-PP) and the BN@SiO 2-NH2, putting the mixture into a double-screw extruder, and carrying out melt extrusion granulation at 180-220 ℃ to obtain compatilizer granules. Further, the grafting rate of the maleic anhydride grafted polypropylene is 1.2% -1.5%. Further, the preparation process of the BN@SiO 2-NH2 is as follows: 1) Mixing boron nitride and urea according to a mass ratio of 1:20-40, placing the mixture in a ball mill, wherein a ball material ratio is 80:1-120:1, a rotating speed is 400-600 r/min, and performing mechanical stripping after ball milling for 15-20 hours to obtain stripped boron nitride which is recorded as BN; 2) Ultrasonically dispersing BN in an ethanol water solution, regulating the pH to 8-9 by using dilute ammonia water, slowly dripping tetraethoxysilane into the BN dispersion, stirring for 6 hours at 40 ℃, and centrifugally washing to obtain BN@SiO 2; 3) And dispersing BN@SiO 2 in ethanol, and adding 30-50% of gamma-aminopropyl triethoxysilane by mass of BN@SiO 2 to perform reflux grafting to obtain BN@SiO 2-NH2. Further, the filler is selected from one or more of aluminum oxide, calcium carbonate, titanium dioxide and barium titanate. Further, the nucleating agent is talcum powder with the grain diameter of 100-200nm, and the antioxidant is antioxidant 1010 or antioxidant 168. The second object of the present invention is to provide a method for preparing the biaxially orie