High-temperature-resistant polypropylene capacitor film, manufacturing method and capacitor

Abstract

The invention relates to the technical field of capacitors, in particular to a high-temperature-resistant polypropylene capacitor film, a manufacturing method and a capacitor. The heat-resisting interlayer comprises first strip-shaped coatings distributed in the first direction at intervals and second strip-shaped coatings distributed in the second direction at intervals, and the first strip-shaped coatings and the second strip-shaped coatings intersect and form regularly-distributed through holes. A traditional capacitor film with a single-layer structure is changed, the heat-resistant interlayer is arranged between every two adjacent polypropylene layers, and a multi-layer composite structure in which the polypropylene layers and the heat-resistant interlayers are alternately stacked in the thickness direction is formed, so that the heat resistance of the capacitor film is improved; moreover, two adjacent polypropylene layers can be polymerized through the through holes in the heat-resistant interlayer, so that the integrity of the capacitor is ensured.

Description

Technical Field

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

[0002] Polypropylene capacitor film is a high-performance material widely used in the modern electronics industry, mainly used to manufacture film capacitors. Due to its high breakdown voltage strength, low dielectric constant, good mechanical properties and stable chemical properties, this type of capacitor is known for its low loss, high stability and long life, and is suitable for a variety of power and electronic equipment, such as power transmission systems, inverters, electric vehicles, household appliances and communication equipment.

[0003] However, due to the material properties of polypropylene, it can only work in an environment below 85°C, which is not conducive to high-temperature working environments. Summary of the invention

[0004] In response to the above-mentioned technical problems, the present application provides a high-temperature resistant polypropylene capacitor film, a manufacturing method and a capacitor.

[0005] The present invention provides the following technical solutions:

[0006] In a first aspect, the present application provides a high temperature resistant polypropylene capacitor film, comprising:

[0007] Polypropylene layer;

[0008] and a heat-resistant interlayer, wherein the heat-resistant interlayer comprises a strip coating 1 spaced apart along a first direction and a strip coating 2 spaced apart along a second direction, wherein the strip coating 1 and the strip coating 2 intersect to form regularly distributed through holes.

[0009] As a further technical solution of the present invention, the heat-resistant interlayer has at least two layers, and in two adjacent heat-resistant interlayers, the through holes are staggeredly distributed on the horizontal projection plane.

[0010] As a further technical solution of the present invention, the heat-resistant interlayer includes a binder and a ceramic material, and the mass ratio of the binder to the ceramic material is 1:(3-7).

[0011] As a further technical solution of the present invention, the thickness of the polypropylene layer is 1-2 μm, and the thickness of the heat-resistant interlayer is 0.5-1 μm.

[0012] As a further technical solution of the present invention, the ratio of the thickness of the polypropylene layer to the thickness of the heat-resistant interlayer is 2:1.

[0013] As a further technical solution of the present invention, the binder is one of epoxy resin, polyurethane, silicone resin, acrylate, polyimide, phenolic resin, fluoropolymer, and polyester resin.

[0014] As a further technical solution of the present invention, the ceramic material is one of aluminum oxide, boron nitride, silicon dioxide, silicon carbide, zirconium oxide, barium titanate, aluminum nitride, and calcium phosphate.

[0015] In a second aspect, the present application provides a method for manufacturing a high temperature resistant polypropylene capacitor film, the specific steps of which are as follows:

[0016] Step 1, using a polypropylene layer as a substrate;

[0017] Step 2, forming a heat-resistant interlayer on the substrate;

[0018] The heat-insulating coating in Preparation Example 1 is applied on the substrate in a first direction at intervals to form a stripe coating 1, and the heat-insulating coating in Preparation Example 1 is applied in a second direction at intervals to form a stripe coating 2;

[0019] Step 3, affixing a polypropylene layer to the formed heat-resistant interlayer as a new substrate;

[0020] Step 4, repeating steps 2 and 3 to form a polypropylene layer and a heat-resistant interlayer stacked in sequence, and staggering the strip coating 1 and the strip coating 2 in two adjacent heat-resistant interlayers;

[0021] Step 5: hot-press the laminated polypropylene layer and the heat-resistant interlayer to form a capacitor film, wherein the hot-pressing pressure is 2 kg and the temperature is 130-140°C.

[0022] As a further technical solution of the present invention, the preparation steps of the thermal insulation coating are as follows:

[0023] The binder and the ceramic material are put into a stirring tank according to a certain mass ratio and stirred until all the ceramic particles are evenly distributed in the binder to form a thermal insulation coating;

[0024] Among them, the stirring speed is 500-1000RPM.

[0025] In a third aspect, the present application provides a capacitor, comprising the above-mentioned high temperature resistant polypropylene capacitor film.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present application provides a high temperature resistant polypropylene capacitor film, which changes the traditional single-layer structure capacitor film, arranges a heat-resistant interlayer between two adjacent polypropylene layers, and forms a multi-layer composite structure in which polypropylene layers and heat-resistant interlayers are alternately stacked in the thickness direction, thereby improving the heat resistance of the capacitor film;

[0028] Furthermore, two adjacent polypropylene layers can be polymerized through the through holes on the heat-resistant interlayer to ensure the integrity of the capacitor.

[0029] At the same time, the through holes on two adjacent heat-resistant interlayers are staggered, so that the heat-resistant interlayer can still fully cover the capacitor film on a macroscopic horizontal projection plane.

[0030] (2) The present application provides a method for manufacturing a high-temperature resistant polypropylene capacitor film, which can manufacture a multilayer capacitor film, wherein a heat-resistant interlayer is provided between two adjacent polypropylene layers, and a multilayer composite structure is formed in which polypropylene layers and heat-resistant interlayers are alternately stacked in the thickness direction, thereby improving the heat resistance of the capacitor film;

[0031] Furthermore, two adjacent polypropylene layers can be polymerized through the through holes on the heat-resistant interlayer to ensure the integrity of the capacitor.

[0032] At the same time, the through holes on two adjacent heat-resistant interlayers are staggered, so that the heat-resistant interlayer can still fully cover the capacitor film on a macroscopic horizontal projection plane.

[0033] (3) The present application provides a capacitor, in which a multi-layer capacitor film is used, a heat-resistant interlayer is arranged between two adjacent polypropylene layers, and a multi-layer composite structure is formed in which the polypropylene layer and the heat-resistant interlayer are alternately stacked in the thickness direction, thereby improving the heat resistance of the capacitor film;

[0034] Furthermore, two adjacent polypropylene layers can be polymerized through the through holes on the heat-resistant interlayer to ensure the integrity of the capacitor.

[0035] At the same time, the through holes on two adjacent heat-resistant interlayers are staggered, so that the heat-resistant interlayer can still fully cover the capacitor film on a macroscopic horizontal projection plane. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 The overall structure schematic diagram of the high temperature resistant polypropylene capacitor film is shown;

[0038] Figure 2 A schematic diagram of the structure of a heat-resistant interlayer is shown;

[0039] Figure 3A schematic diagram of the matching structure of two adjacent heat-resistant interlayers is shown. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0041] In the following examples of the present application, the main components involved, unless otherwise specified, were purchased from commercially available products.

[0042] Figure 1 The overall structure schematic diagram of the high temperature resistant polypropylene capacitor film is shown; Figure 1 The high temperature resistant polypropylene capacitor film comprises polypropylene layers 110 and heat resistant interlayers 120 which are alternately distributed along the thickness direction; the traditional single-layer structure is set as a composite structure, so that the heat resistant interlayer 120 is spaced between two adjacent polypropylene layers 110, delaying the transfer of heat along the thickness direction, reducing the working temperature of the inner layer, and improving the heat resistance of the capacitor film.

[0043] Figure 2 A schematic diagram of the structure of the heat-resistant interlayer 120 is shown; Figure 2 In the embodiment, the heat-resistant interlayer 120 includes a strip coating 121 spaced apart along a first direction and a strip coating 122 spaced apart along a second direction, and the strip coating 121 and the strip coating 122 intersect and form regularly distributed through holes 123; that is, the heat-resistant interlayer 120 has through holes 123, and the two polypropylene layers 110 spaced apart by the heat-resistant interlayer 120 can be polymerized through the through holes 123 to ensure the integrity of the capacitor film.

[0044] Figure 3The schematic diagram of the matching structure of two adjacent heat-resistant interlayers 120 is shown; in the figure, in the two adjacent heat-resistant interlayers 120, the through holes 123 are staggered on the horizontal projection plane; that is, the heat transfer path when transferring from the outside to the inside is winding, which prolongs the heat transfer time and improves the heat resistance of the capacitor film; the heat-resistant interlayer 120 has at least two layers, that is, the high-temperature resistant polypropylene capacitor film has at least five layers, namely three polypropylene layers 110 and two heat-resistant interlayers 120; the heat-resistant interlayer 120 includes bonding The binder and ceramic material have a mass ratio of 1:(3-7); the ceramic material accounts for a large proportion to provide excellent thermal barrier effect, while an appropriate amount of binder ensures good bonding strength and processing performance; the thickness of the polypropylene layer 110 is 1-2μm, and the thickness of the heat-resistant interlayer 120 is 0.5-1μm; in this way, the total thickness of the five-layer capacitor film is 8μm; the ratio of the thickness of the polypropylene layer 110 to the thickness of the heat-resistant interlayer 120 is 2:1; the polypropylene content in the capacitor film is ensured.

[0045] The adhesive is one of epoxy resin, polyurethane, silicone resin, acrylate, polyimide, phenolic resin, fluoropolymer and polyester resin.

[0046] The ceramic material is one of aluminum oxide, boron nitride, silicon dioxide, silicon carbide, zirconium oxide, barium titanate, aluminum nitride and calcium phosphate. Specific embodiments

[0048] Preparation Examples 1-5 are used to prepare the heat-insulating coating required to form the heat-resistant interlayer 120 .

[0049] Preparation Example 1

[0050] The binder and ceramic material are placed in a mixing tank at a mass ratio of 1:3 and stirred until all the ceramic particles are evenly distributed in the binder to form a thermal insulation coating. The stirring speed is 500RPM.

[0051] Preparation Example 2

[0052] The binder and ceramic material are placed in a mixing tank at a mass ratio of 1:4 and stirred until all the ceramic particles are evenly distributed in the binder to form a thermal insulation coating. The stirring speed is 500RPM.

[0053] Preparation Example 3

[0054] The binder and ceramic material are put into a stirring tank at a mass ratio of 1:5 and stirred until all the ceramic particles are evenly distributed in the binder to form a thermal insulation coating. The stirring speed is 500RPM.

[0055] Preparation Example 4

[0056] The binder and ceramic material are put into a stirring tank at a mass ratio of 1:6 and stirred until all the ceramic particles are evenly distributed in the binder to form a thermal insulation coating. The stirring speed is 800RPM.

[0057] Preparation Example 5

[0058] The binder and ceramic material are put into a stirring tank at a mass ratio of 1:7 and stirred until all the ceramic particles are evenly distributed in the binder to form a thermal insulation coating. The stirring speed is 1000RPM.

[0059] Embodiments 1-5 are used to prepare high temperature resistant polypropylene capacitor films. It should be noted that the number of layers of the capacitor films prepared therein is five, but in some other embodiments, the number of layers of the capacitor film is not limited; and the polypropylene layer 110 used in this application adopts the existing technology without too many restrictions.

[0060] Example 1

[0061] This embodiment provides a method for preparing a high temperature resistant polypropylene capacitor film, and the specific steps are as follows:

[0062] Step 1, using a polypropylene layer 110 as a substrate;

[0063] Step 2, forming a heat-resistant interlayer 120 on the substrate;

[0064] The heat-insulating coating material in Preparation Example 1 is applied on the substrate in a first direction at intervals to form a stripe coating layer 121, and the heat-insulating coating material in Preparation Example 1 is applied in a second direction at intervals to form a stripe coating layer 2 122;

[0065] Step 3, a polypropylene layer 110 is attached to the formed heat-resistant interlayer 120 as a new substrate;

[0066] Step 4, repeating step 2 and step 3 to form a polypropylene layer 110 and a heat-resistant interlayer 120 stacked in sequence, and making the strip coating 1 121 and the strip coating 2 122 in two adjacent heat-resistant interlayers 120 staggered;

[0067] Step five: hot-press the laminated polypropylene layer 110 and the heat-resistant interlayer 120 to form a capacitor film, wherein the pressure is 2 kg and the temperature is 130° C.

[0068] The difference between Examples 2-5 and Example 1 is that the heat-insulating coatings prepared in Preparation Examples 2-8 are used respectively. The high-temperature resistant polypropylene capacitor films prepared in Examples 1-5 are tested, and the test results are shown in Table 1.

[0069] The thermal shrinkage rate is measured according to GB / T13541, and the test condition is that the heat-resistant interlayer is placed in a 120°C oven for 10 minutes; the DC experiment is tested in accordance with GB / T13542.2-2009.

[0070]

[0071] It can be seen from the test results of Examples 1 to 5 in Table 1 above that the MD of the capacitor film at a heat-resistant interlayer of 120°C is below 1.2% and the TD is reduced to below 0.2%. That is to say, the capacitor film can work stably at a heat-resistant interlayer of 120°C, which improves the heat resistance of the capacitor film and is beneficial to a high-temperature working environment. In addition, in Examples 1 to 5, as the proportion of the binder in the heat-resistant interlayer 120 decreases and the proportion of the ceramic material increases, the heat resistance of the capacitor film shows an increasing trend.

[0072] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. High temperature resistant polypropylene capacitor film, characterized in that: Includes alternating distribution along the thickness direction: Polypropylene layer; and a heat-resistant interlayer, wherein the heat-resistant interlayer comprises a strip coating 1 spaced apart along a first direction and a strip coating 2 spaced apart along a second direction, wherein the strip coating 1 and the strip coating 2 intersect to form regularly distributed through holes.

2. The high temperature resistant polypropylene capacitor film according to claim 1, characterized in that: The heat-resistant interlayer has at least two layers, and in two adjacent heat-resistant interlayers, the through holes are staggeredly distributed on a horizontal projection plane.

3. The high temperature resistant polypropylene capacitor film according to claim 2, characterized in that: The heat-resistant interlayer includes a binder and a ceramic material, and the mass ratio of the binder to the ceramic material is 1:(3-7).

4. The high temperature resistant polypropylene capacitor film according to claim 3, characterized in that: The thickness of the polypropylene layer is 1-2 μm, and the thickness of the heat-resistant interlayer is 0.5-1 μm.

5. The high temperature resistant polypropylene capacitor film according to claim 3, characterized in that: The ratio of the thickness of the polypropylene layer to the thickness of the heat-resistant interlayer is 2:

1.

6. The high temperature resistant polypropylene capacitor film, manufacturing method and capacitor according to claim 5, characterized in that: The adhesive is one of epoxy resin, polyurethane, silicone resin, acrylate, polyimide, phenolic resin, fluoropolymer and polyester resin.

7. The high temperature resistant polypropylene capacitor film, manufacturing method and capacitor according to claim 6, characterized in that: The ceramic material is one of aluminum oxide, boron nitride, silicon dioxide, silicon carbide, zirconium oxide, barium titanate, aluminum nitride and calcium phosphate.

8. The method for manufacturing a high temperature resistant polypropylene capacitor film according to any one of claims 1 to 7, characterized in that: The specific steps are as follows: Step 1, using a polypropylene layer as a substrate; Step 2, forming a heat-resistant interlayer on the substrate; The heat-insulating coating in Preparation Example 1 is applied on the substrate in a first direction at intervals to form a stripe coating 1, and the heat-insulating coating in Preparation Example 1 is applied in a second direction at intervals to form a stripe coating 2; Step 3, affixing a polypropylene layer to the formed heat-resistant interlayer as a new substrate; Step 4, repeating steps 2 and 3 to form a polypropylene layer and a heat-resistant interlayer stacked in sequence, and staggering the strip coating 1 and the strip coating 2 in two adjacent heat-resistant interlayers; Step 5: hot-press the laminated polypropylene layer and the heat-resistant interlayer to form a capacitor film, wherein the hot-pressing pressure is 2 kg and the temperature is 130-140°C.

9. The method for manufacturing a high temperature resistant polypropylene capacitor film according to claim 8, characterized in that: The preparation steps of the thermal insulation coating are as follows: The binder and the ceramic material are put into a stirring tank according to a certain mass ratio and stirred until all the ceramic particles are evenly distributed in the binder to form a thermal insulation coating; Among them, the stirring speed is 500-1000RPM.

10. A capacitor, characterized in that: The invention comprises the high temperature resistant polypropylene capacitor film according to any one of claims 1 to 7.

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