Capacity-increasing modified polypropylene capacitor film material with high dielectric property, preparation method and capacitor

Abstract

The invention provides a compatibilization modified polypropylene capacitor film material with high dielectric property, a preparation method and a capacitor, polypropylene is used as a matrix, ZrO2 with high dielectric constant is used as a nano filler, maleic anhydride grafted polypropylene is used as a compatilizer, and the compatibilization modified polypropylene capacitor film material with high dielectric property is prepared by a method of reducing interfacial force through the compatilizer. The dispersity of the nano zirconium oxide in the matrix is improved, the agglomeration phenomenon of the nano zirconium oxide is reduced, and the nano zirconium oxide is more uniformly dispersed in the matrix, so that the dielectric property of the nano zirconium oxide is improved. The polypropylene-based composite material has the advantages of safety, stability, simplicity in operation, low production cost, good mechanical properties and the like, is suitable for large-scale production, and has a wide application prospect; the thin film capacitor prepared from the material has the advantages in the aspects of current bearing, dielectric loss bearing and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material preparation, and in particular to a capacitated and modified high-dielectric-performance polypropylene capacitor film material, a preparation method thereof, and a capacitor. Background Art

[0002] Capacitors are one of the three most fundamental components in circuits, playing important roles in energy storage, filtering, phase modulation, and coupling. Capacitors are primarily classified into ceramic capacitors, electrolytic capacitors, and film capacitors. Film capacitors are a key category due to their high current carrying capacity and low dielectric loss. Currently, the most widely used film capacitor is polypropylene film capacitor. Electrical-grade polypropylene particles, unlike food-grade and packaging-grade polypropylene particles, require extremely high purity, excellent temperature resistance, and electrical insulation strength.

[0003] Currently, the polypropylene film materials used lag significantly behind those of foreign polypropylene particles in terms of temperature resistance and electrical insulation strength, as well as isotacticity and ash impurities. Therefore, a new technical approach is needed to develop a new polypropylene film material that improves its dielectric and crystallization properties. Summary of the Invention

[0004] In view of this, the present invention proposes, on one hand, a capacitated and modified high-dielectric performance polypropylene capacitor film material, comprising the following components in parts by weight: a base material, 60 to 100 parts; a conductive filler, 0 to 30 parts; and a compatibilizer, 0 to 10 parts. The base material is polypropylene, the conductive filler is nano-zirconia, and the compatibilizer is maleic anhydride-grafted polypropylene.

[0005] Furthermore, the polypropylene is high dielectric performance polypropylene, its model is HC300BF, and its dielectric constant is 2.2.

[0006] Furthermore, the particle size of the nano zirconium oxide is ≤100 nm.

[0007] Furthermore, the grafting rate of the maleic anhydride grafted polypropylene is less than 2%.

[0008] Preferably, the grafting rate of maleic anhydride grafted polypropylene is 1%.

[0009] Specifically, maleic anhydride grafted polypropylene can significantly improve the compatibility of polypropylene with other materials; this compatibilizer can increase the tensile and impact strength of the composite material, enhance the dispersion of fillers, and thus improve the mechanical properties of filled polypropylene. Specifically, the polypropylene capacitor film material uses PP as a matrix, ZrO2 with a high dielectric constant as a nanofiller, and maleic anhydride grafted polypropylene as a compatibilizer. By reducing interfacial forces through the compatibilizer, the dispersion of nano-zirconium oxide in the matrix is ​​improved, the agglomeration of nano-zirconium oxide is reduced, and the nano-zirconium oxide is dispersed more evenly in the matrix, thereby improving its dielectric properties. The polypropylene-based composite material obtained by the invention has the advantages of safety and stability, simple operation, low production cost and good mechanical properties. It is suitable for large-scale production and has broad application prospects.

[0010] The second aspect of the present invention further provides a method for preparing a capacitated and modified high dielectric performance polypropylene capacitor film material, comprising: Raw material preparation stage: weigh polypropylene, nano zirconium oxide, and maleic acid rod grafted polypropylene according to the formula, and dry them for later use; Material preparation stage: polypropylene, nano-zirconia, and maleic acid rod grafted polypropylene are dried, mixed evenly according to a certain ratio, and then melt blended and dispersed in a Harp internal mixer; Composite material hot pressing molding stage: the above mixture is pressed into shape to obtain a composite material.

[0011] Furthermore, during the drying process, the drying temperature is 50-90°C.

[0012] Furthermore, the melt blending temperature is 170-190° C., the rotation speed is 50-60 rpm / min, and the time is 6-15 min.

[0013] Furthermore, the hot pressing temperature is 180-200° C., the time is 4-15 min, and the pressure is 5-20 MPa.

[0014] Specifically, the method is simple to operate. The polypropylene capacitor film material prepared by this method uses PP as a matrix, ZrO2 with a high dielectric constant as a nanofiller, and maleic anhydride grafted polypropylene as a compatibilizer. The compatibilizer reduces the interfacial force, thereby improving the dispersion of nano-zirconium oxide in the matrix, reducing the agglomeration of nano-zirconium oxide, and making it more uniformly dispersed in the matrix, thereby improving its dielectric properties. The polypropylene-based composite material obtained by the invention has the advantages of safety and stability, simple operation, low production cost and good mechanical properties, is suitable for large-scale production, and has broad application prospects.

[0015] The third aspect of the present invention further provides a film capacitor, which is made of any of the above-mentioned capacitively modified high dielectric performance polypropylene capacitor film materials.

[0016] Specifically, the material selected for the film capacitor can meet the requirements of performance such as temperature resistance and electrical insulation strength, making the film capacitor quite advantageous in terms of carrying current and dielectric loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings: Figure 1 A flow chart for preparing a capacitated and modified high dielectric performance polypropylene capacitor film composite material provided by an embodiment of the present invention; Figure 2 A comparison chart of the dielectric constants of the ZrO2 / PP composite material with PP-g-MAH added and the ZrO2 / PP composite material without PP-g-MAH added provided in an embodiment of the present invention; Figure 3 A comparison chart of dielectric loss between a ZrO2 / PP composite material with PP-g-MAH added and a ZrO2 / PP composite material without PP-g-MAH added provided in an embodiment of the present invention; Figure 4 This is a comparison chart of the thermal stability of the ZrO2 / PP composite material with the addition of PP-g-MAH and the ZrO2 / PP composite material without the addition of PP-g-MAH provided in the embodiments of the present invention. DETAILED DESCRIPTION

[0018] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, unless there is a conflict, the embodiments of the present disclosure and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0019] The embodiment of the present invention discloses a capacitated and modified high-dielectric polypropylene capacitor film material, comprising the following components in parts by weight: 60-100 parts of high-dielectric polypropylene; 0-30 parts of nano-zirconium oxide; and 0-10 parts of maleic anhydride-grafted polypropylene.

[0020] It should be noted that polypropylene is abbreviated as PP, maleic anhydride grafted polypropylene is abbreviated as PP-g-MAH, and zirconium oxide is abbreviated as ZrO 2。

[0021] In this embodiment, the high dielectric performance polypropylene is HC300BF, and the dielectric constant is 2.2.

[0022] In this embodiment, the particle size of the nano-zirconium oxide is ≤100 nm.

[0023] In this embodiment, the grafting rate of maleic anhydride grafted polypropylene is less than 2%.

[0024] In this embodiment, the grafting rate of maleic anhydride grafted polypropylene is 1%.

[0025] The polypropylene capacitor film material disclosed in this embodiment has the following advantages: PP is used as the matrix, ZrO2 with a high dielectric constant is used as the nanofiller, and maleic anhydride-grafted polypropylene is used as the compatibilizer. The compatibilizer reduces interfacial forces, thereby improving the dispersion of nano-zirconia within the matrix, reducing nano-zirconia agglomeration, and making the dispersion more uniform within the matrix, thereby improving its dielectric properties. The resulting polypropylene-based composite material has the advantages of safety, stability, simple operation, low production cost, and good mechanical properties. It is suitable for large-scale production and has broad application prospects.

[0026] The embodiment of the present invention further discloses a method for preparing a capacitated and modified polypropylene capacitor film material with high dielectric properties, comprising: S01 Raw material preparation stage: weigh polypropylene, nano zirconium oxide, and maleic acid rod grafted polypropylene according to the formula, and dry them for later use; S02 composite material preparation stage: polypropylene, nano-zirconia, and maleic acid rod grafted polypropylene are dried, mixed evenly according to a certain ratio, and then melt blended and dispersed in a Harp internal mixer; S03 Composite material hot pressing molding stage: the above mixture is pressed into shape to obtain a composite material.

[0027] In this embodiment, during the drying process, the drying temperature is 50-90°C.

[0028] In this embodiment, the melt blending temperature is 170-190° C., the rotation speed is 50-60 rpm / min, and the time is 6-15 min.

[0029] In this embodiment, the hot pressing temperature is 180-200° C., the time is 4-15 minutes, and the pressure is 5-20 MPa.

[0030] The method for preparing a polypropylene capacitor film material disclosed in an embodiment of the present invention has the following advantages: simple operation. The polypropylene capacitor film material prepared by this method uses PP as a matrix, ZrO2 with a high dielectric constant as a nanofiller, and maleic anhydride grafted polypropylene as a compatibilizer. The compatibilizer reduces interfacial forces, thereby improving the dispersion of nano-zirconium oxide within the matrix, reducing nano-zirconium oxide agglomeration, and making it more evenly dispersed within the matrix, thereby improving its dielectric properties. The resulting polypropylene-based composite material has the advantages of safety, stability, simple operation, low production cost, and good mechanical properties. It is suitable for large-scale production and has broad application prospects.

[0031] The embodiment of the present invention further discloses a film capacitor, which is made by using the capacitively modified high dielectric performance polypropylene capacitor film material disclosed in any one of the above items.

[0032] The film capacitor disclosed in this embodiment uses materials that can meet the requirements of performance such as temperature resistance and electrical insulation strength, so that the film capacitor has advantages in terms of carrying current and dielectric loss.

[0033] The present invention will be further explained below with reference to specific examples: In the following examples, unless otherwise specified, the raw materials can be purchased from the market, the operating methods used are conventional operating methods, the equipment used are conventional equipment, the polypropylene used is high dielectric polypropylene, and the zirconium oxide used is nano zirconium oxide.

[0034] Example 1 A capacitated and modified high dielectric performance polypropylene capacitor film composite material is prepared by the following steps: (1) Raw material preparation: Weigh a certain amount of raw materials according to the formula, where the polypropylene brand is Borealis HC300BF and the nano zirconium oxide is from Shanghai Aladdin Biochemical Technology Co., Ltd., with a particle size of ≤100nm. Dry the PP and ZrO2 for later use; (2) Material preparation stage: 60 g of PP was weighed and melt-blended in a Harp internal mixer; (3) Composite material compression molding stage: The above mixture is compression molded to obtain a composite material.

[0035] Wherein, the drying temperature in step (1) is 60°C.

[0036] The temperature of the melt blending in step (2) is 170° C., the rotation speed is 50 rpm / min, and the time is 8 to 12 minutes.

[0037] The hot pressing temperature in step (3) is 180°C, the time is 8 minutes, and the pressure is 10 MPa.

[0038] After testing, the dielectric constant of Example 1 is 2.25, the dielectric loss is 0.004, and the thermal decomposition temperature is 409.4°C. Figure 2-4 shown.

[0039] Example 2 A capacitated and modified high dielectric performance polypropylene capacitor film composite material is prepared by the following steps: (1) Raw material preparation stage: weigh a certain amount of raw materials according to the formula, and dry PP and ZrO2 for later use; (2) Material preparation stage: Weigh 3g ZrO2 and 6g maleic anhydride grafted polypropylene, then weigh 51g PP and mix them evenly, and then melt blend and disperse them in a Harp internal mixer; (3) Composite material compression molding stage: The above mixture is compression molded to obtain a composite material.

[0040] Wherein, the drying temperature in step (1) is 70°C.

[0041] The temperature of the melt blending in step (2) is 180° C., the rotation speed is 55 rpm / min, and the time is 8 to 12 minutes.

[0042] The hot pressing temperature in step (3) is 190°C, the time is 9 minutes, and the pressure is 13 MPa.

[0043] After testing, the dielectric constant of Example 2 is 2.81, the dielectric loss is 0.015, and the thermal decomposition temperature is 412.2°C. Figure 2-4 shown.

[0044] Example 3 A capacitated and modified high dielectric performance polypropylene capacitor film composite material is prepared by the following steps: (1) Raw material preparation stage: weigh a certain amount of raw materials according to the formula, and dry PP and ZrO2 for later use; (2) Material preparation stage: Weigh 18 g ZrO2 and 6 g maleic anhydride grafted polypropylene, then weigh 36 g PP and mix them evenly, and then melt blend and disperse them in a Harp internal mixer; (3) Composite material compression molding stage: The above mixture is compression molded to obtain a composite material.

[0045] Wherein, the drying temperature in step (1) is 80°C.

[0046] The temperature of the melt blending in step (2) is 190° C., the rotation speed is 60 rpm / min, and the time is 8 to 12 minutes.

[0047] The hot pressing temperature in step (3) is 200°C, the time is 10 min, and the pressure is 15 MPa.

[0048] After testing, the dielectric constant of Example 3 is 3.72, the dielectric loss is 0.039, and the thermal decomposition temperature is 425.7°C. Figure 2-4 shown.

[0049] Comparative Example 1 A dielectric performance polypropylene capacitor film composite material is prepared by the following steps: (1) Raw material preparation stage: weigh a certain amount of raw materials according to the formula, dry PP and ZrO2 for later use (2) Material preparation stage: weigh 60g PP and melt blend and disperse it in a Harp internal mixer; (3) Composite material compression molding stage: The above mixture is compression molded to obtain a composite material.

[0050] Wherein, the drying temperature in step (1) is 60°C.

[0051] The temperature of the melt blending in step (2) is 170° C., the rotation speed is 50 rpm / min, and the time is 8 to 12 minutes.

[0052] The hot pressing temperature in step (3) is 180°C, the time is 8 minutes, and the pressure is 10-15 MPa.

[0053] After testing, the dielectric constant of comparative example 1 is 2.25, the dielectric loss is 0.004, and the thermal decomposition temperature is 409.4°C. Figure 2-4 shown.

[0054] Comparative Example 2 A dielectric performance polypropylene capacitor film composite material is prepared by the following steps: (1) Raw material preparation stage: weigh a certain amount of raw materials according to the formula, dry PP and ZrO2 for later use (2) Material preparation stage: weigh 57g PP and 3g ZrO2, mix them evenly, and then melt blend and disperse them in a Harp internal mixer; (3) Composite material compression molding stage: The above mixture is compression molded to obtain a composite material.

[0055] Wherein, the drying temperature in step (1) is 70°C.

[0056] The temperature of the melt blending in step (2) is 180° C., the rotation speed is 55 rpm / min, and the time is 8 to 12 minutes.

[0057] The hot pressing temperature in step (3) is 190°C, the time is 9 minutes, and the pressure is 10-15 MPa.

[0058] After testing, the dielectric constant of comparative example 2 is 1.29, the dielectric loss is 0.049, and the thermal decomposition temperature is 417.5°C. Figure 2-4 shown.

[0059] Comparative Example 3 A dielectric performance polypropylene capacitor film composite material is prepared by the following steps: (1) Raw material preparation stage: weigh a certain amount of raw materials according to the formula, dry PP and ZrO2 for later use (2) Material preparation stage: weigh 42g PP and 18g ZrO2 and mix them evenly, then melt blend and disperse them in a Harp internal mixer; (3) Composite material compression molding stage: The above mixture is compression molded to obtain a composite material.

[0060] Wherein, the drying temperature in step (1) is 70°C.

[0061] The temperature of the melt blending in step (2) is 180° C., the rotation speed is 55 rpm / min, and the time is 8 to 12 minutes.

[0062] The hot pressing temperature in step (3) is 190°C, the time is 9 minutes, and the pressure is 13 MPa.

[0063] After testing, the dielectric constant of comparative example 3 is 4.42, the dielectric loss is 0.28, and the thermal decomposition temperature is 429.2°C. Figure 2-4 shown.

[0064] Result detection The dielectric properties of the polypropylene-based composite materials prepared in Examples 1, 2, 3 and Comparative Examples 1, 2, 3 were tested using a broadband dielectric impedance spectrometer to obtain the dielectric constant and dielectric loss of each sample. The test frequency was 2×10 1 ~2×10 6 Hz, and the test temperature was room temperature. A thermogravimetric analyzer was also used to characterize the high-temperature thermal stability of the composite material. Under a nitrogen atmosphere, the temperature was raised from 30°C to 800°C at a rate of 10°C / min. These test results demonstrate that using ZrO2, a conductive filler with an ultra-high dielectric constant, and maleic anhydride-grafted polypropylene as a compatibilizer, the compatibilizer modifies the interfacial forces between the matrix and filler, reducing nano-zirconia agglomeration and resulting in a more uniform dispersion within the matrix. This enhances the interfacial bonding between the groups and the filler, thereby improving the dielectric, mechanical, and thermal stability of the polymer nanocomposite.

[0065] In summary, the capacitated, modified, high-dielectric polypropylene capacitor film material and preparation method provided in this embodiment offer the following advantages: Utilizing PP as the matrix, high-dielectric-constant ZrO2 nanofiller, and maleic anhydride-grafted polypropylene as a compatibilizer, the compatibilizer reduces interfacial forces, thereby improving the dispersion of nano-zirconia within the matrix, reducing nano-zirconia agglomeration, and achieving a more uniform dispersion within the matrix, thereby enhancing dielectric properties. The resulting polypropylene-based composite material boasts advantages such as safety, stability, ease of operation, low production cost, and excellent mechanical properties. It is suitable for large-scale production and has broad application prospects.

[0066] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0067] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0068] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A capacitated and modified high dielectric performance polypropylene capacitor film material, characterized in that: The composition comprises the following components in parts by weight: 60-100 parts of base material; 0-30 parts of conductive filler; 0-10 parts of compatibilizer; the base material is polypropylene, the conductive filler is nano-zirconia, and the compatibilizer is maleic anhydride grafted polypropylene.

2. The capacitated and modified high dielectric performance polypropylene capacitor film material according to claim 1, characterized in that: The polypropylene is a high dielectric performance polypropylene, the model of which is HC300BF and the dielectric constant is 2.

2.

3. The capacitated and modified high dielectric performance polypropylene capacitor film material according to claim 1, characterized in that: The particle size of the nano zirconium oxide is ≤100 nm.

4. The capacitated and modified high dielectric performance polypropylene capacitor film material according to claim 1, characterized in that: The grafting rate of the maleic anhydride grafted polypropylene is less than 2%.

5. The capacitated and modified high dielectric performance polypropylene capacitor film material according to claim 4, characterized in that: The grafting rate of the maleic anhydride grafted polypropylene is 1%.

6. A method for preparing a capacitated and modified polypropylene capacitor film material with high dielectric properties, characterized in that: include: Masterbatch preparation stage: weigh polypropylene, nano-zirconia, and maleic acid rod grafted polypropylene according to the formula, and dry them for later use; Masterbatch preparation stage: Mix the dried polypropylene, nano-zirconia, and maleic acid rod grafted polypropylene in a preset ratio, and then melt blend and disperse them in a Harp internal mixer; Composite material hot pressing molding stage: the above mixture is pressed into shape to obtain a composite material.

7. The method for preparing the capacitated and modified high dielectric performance polypropylene capacitor film material according to claim 6, characterized in that: During the drying process, the drying temperature is 50-90°C.

8. The method for preparing the capacitated and modified high dielectric performance polypropylene capacitor film material according to claim 6, characterized in that: The melt blending temperature is 170-190° C., the rotation speed is 50-60 rpm / min, and the time is 6-15 min.

9. The method for preparing the capacitated and modified high dielectric performance polypropylene capacitor film material according to claim 6, characterized in that: In the hot pressing molding, the hot pressing temperature is 180-200° C., the time is 4-15 minutes, and the pressure is 5-20 MPa.

10. A film capacitor, characterized in that: The invention is made of the capacitated and modified high dielectric performance polypropylene capacitor film material according to any one of claims 1 to 5.

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