Preparation method and application of multi-medium synergistically modified high-thermal-conductivity mica tape

Abstract

The invention discloses a preparation method and application of a multi-medium synergistically modified high-thermal-conductivity mica tape, and relates to the technical field of thermal-conductive insulating materials. The invention aims to solve the problems that the traditional mica tape cannot have high thermal conductivity, low dielectric loss and high insulating property at the same time, the mica tape cannot be fully impregnated after being doped with high-thermal-conductivity filler, and the final thermal conductivity is relatively low as a complete three-dimensional heat-conducting network cannot be formed in the mica tape. The spherical boron nitride is added into the epoxy resin adhesive, and in the mica tape dipping process, the spherical boron nitride is reserved in gaps of the glass wool cloth, so that a heat conduction channel is formed in the glass wool cloth, heat conduction between the mica paper layer and the glass wool cloth layer is improved, and a complete three-dimensional heat conduction network is formed in the mica tape; and the thermal conductivity of the mica tape is further obviously improved. The invention can obtain the preparation method and the application of the multi-medium synergistically modified high-thermal-conductivity mica tape.

Description

Technical Field

[0001] The invention relates to the technical field of thermally conductive insulating materials, and in particular to a preparation method and application of a multi-medium synergistically modified high thermal conductive mica tape. Background Art

[0002] In recent years, with the development of science and technology and the advancement of manufacturing technology, large motors are increasingly developing in the direction of high voltage and large capacity. However, how to reduce the operating temperature rise of motors, increase capacity and extend service life has always been a bottleneck problem that the motor manufacturing industry is very concerned about and urgently needs to solve. Improving the thermal conductivity of the motor insulation system can effectively increase the installed capacity per unit volume of the motor and achieve the development direction of small size, light weight and large capacity.

[0003] As the core component of a large-capacity high-voltage motor, the insulation and thermal conductivity of the stator winding directly affect the voltage level, capacity and operating reliability of the motor. The main insulation of the stator winding is composed of three materials: mica paper, glass cloth and epoxy resin. However, the thermal conductivity of the three materials is low. Secondly, the mica tape has a complex structure and many interfaces, resulting in low thermal conductivity of the mica tape. In actual use, traditional mica tape can no longer meet the requirements of existing motor working conditions.

[0004] Therefore, it is urgent to develop high thermal conductivity mica tape. At present, the main way to improve the thermal conductivity of mica tape is to add thermal conductive fillers to the adhesive for direct impregnation. However, this method does not fully impregnate the thermal conductive fillers and cannot form an effective thermal conductive path inside the mica tape. In addition, the mica tape is easy to shed powder and has poor adhesion, which makes it difficult to meet the application requirements of large motors. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that traditional mica tape cannot have high thermal conductivity, low dielectric loss and high insulation performance, and that after being doped with high thermal conductivity fillers, the mica tape cannot be fully impregnated and a complete three-dimensional thermal conductive network cannot be formed inside the mica tape, resulting in low final thermal conductivity. A preparation method and application of a high thermal conductivity mica tape with multi-medium synergistic modification are provided.

[0006] A multi-medium synergistically modified high thermal conductivity mica tape, comprising a three-dimensional thermal conductive network mica paper layer 1, two reinforcing material layers 2 and an adhesive layer 3, wherein the three-dimensional thermal conductive network mica paper layer 1 is arranged between the two reinforcing material layers 2, and the addition amount of the three-dimensional thermal conductive network mica paper layer 1 is 130-160 g / m 2 The adhesive layer 3 is arranged between the three-dimensional thermal conductive network mica paper layer 1 and the reinforcing material layer 2;

[0007] The three-dimensional thermal conductive network mica paper layer 1 is composed of mica flakes and high thermal conductive fillers, wherein the mica flakes are composed of mica flakes smaller than 60 mesh, mica flakes between 60 and 80 mesh, and mica flakes between 80 and 200 mesh, and the mass ratio of the mica flakes smaller than 60 mesh, the mica flakes between 60 and 80 mesh, and the mica flakes between 80 and 200 mesh is (20 to 30): (45 to 60): (5 to 10), and the addition amount of the high thermal conductive filler is 25% of the total mass of the mica flakes;

[0008] The reinforcing material layer 2 is electrical grade glass cloth, and the addition amount is 16-30g / m 2 ;

[0009] The adhesive layer 3 is composed of epoxy resin, curing agent, accelerator and high thermal conductivity filler, and the mass fraction of the high thermal conductivity filler is 6%, 12%, 18%, 24% or 30%;

[0010] The high thermal conductivity fillers in the three-dimensional thermal conductive network mica paper layer 1 and the adhesive layer 3 are both hexagonal boron nitride.

[0011] A method for preparing a multi-medium synergistically modified high thermal conductivity mica tape is carried out according to the following steps:

[0012] Step S1: preparing a three-dimensional thermal conductive network mica paper layer;

[0013] The mica slurry is mixed with a high thermal conductivity filler dispersion, and then subjected to ultrasonic and mechanical stirring, and then vacuum filtration and drying to obtain a three-dimensional thermal conductive network mica paper layer, wherein the high thermal conductivity filler in the high thermal conductivity filler dispersion accounts for 25% of the mass of mica flakes in the mica slurry;

[0014] Step S2: preparing an adhesive containing a high thermal conductive filler;

[0015] A high thermal conductive filler, an epoxy resin and methyl hexahydrophthalic anhydride are mixed, mechanically stirred and ultrasonically dispersed, and then a promoter is added, and then fully stirred under a vacuum environment to obtain an adhesive containing a high thermal conductive filler, wherein the mass fraction of the high thermal conductive filler in the adhesive containing the high thermal conductive filler is 6%, 12%, 18%, 24% or 30%;

[0016] Step S3: preparing a multi-medium synergistically modified high thermal conductivity mica tape;

[0017] Under the temperature condition of 50-80°C, the adhesive containing high thermal conductive filler obtained in step S2 is applied to the two surfaces of the three-dimensional thermal conductive network mica paper layer obtained in step S1, and then the adhesive containing high thermal conductive filler is applied to one surface of the reinforcing material layer, and then the three-dimensional thermal conductive network mica paper layer is placed between the two surfaces of the two reinforcing material layers dipped with the adhesive, and then placed in a vacuum oven for full impregnation under vacuum pressure, and finally hot-pressed for 10-50 minutes under the temperature condition of 60-90°C and the pressure condition of 0.5-5MPa to obtain a multi-medium synergistically modified high thermal conductive mica tape with a complete three-dimensional thermal conductive network, wherein the mass ratio of the three-dimensional thermal conductive network mica paper layer to the reinforcing material layer in the multi-medium synergistically modified high thermal conductive mica tape is (130-160): (16-30).

[0018] The invention discloses an application of a multi-medium synergistically modified high thermal conductivity mica tape, and the application of the multi-medium synergistically modified high thermal conductivity mica tape in the main insulation of the stator winding of a large-capacity high-voltage motor.

[0019] Beneficial effects of the present invention:

[0020] (1) The present invention mixes hexagonal boron nitride, a high thermal conductivity filler with excellent insulation performance, with mica flakes, and prepares a high thermal conductivity mica tape with excellent insulation performance and thermal conductivity through vacuum assisted filtration and hot pressing technology. Hexagonal boron nitride is pre-placed in the mica paper in advance to form a three-dimensional thermal conductive path (such as Figure 1 When the preset hexagonal boron nitride content is low, the thermal conduction paths are few and short, and when the preset content is high, the thermal conduction paths are many and long, effectively forming an out-of-plane thermal conduction path, which greatly improves the thermal conductivity of mica paper and mica tape.

[0021] (2) In the present invention, spherical boron nitride is added to the epoxy resin adhesive. During the process of impregnating the mica tape, the spherical boron nitride is reserved in the gaps of the glass cloth, thereby forming a heat conduction path in the glass cloth, thereby increasing the heat conduction between the mica paper layer and the glass cloth layer, and forming a complete three-dimensional heat conduction network inside the mica tape (such as Figure 2 As shown in Figure 3, the thermal conductivity of the mica tape is further significantly improved.

[0022] (3) When preparing the mica tape, the present invention adopts a temperature-controlled double gluing method, that is, a thin layer of high thermal conductivity adhesive is evenly applied on both sides of the three-dimensional thermal conductive network mica paper layer, and the impregnation temperature is controlled in real time. Then, the glass fiber cloth impregnated with high thermal conductivity adhesive is placed on both sides of the mica paper layer, which can ensure that the epoxy resin adhesive has low viscosity and evenly penetrates into the mica paper, ensuring that the prepared mica tape is uniform and flat.

[0023] (4) The multi-medium synergistically modified high thermal conductivity mica tape prepared by the present invention has high thermal conductivity, good dielectric properties, and maintains excellent insulation properties.

[0024] The present invention can obtain a preparation method and application of a multi-medium synergistically modified high thermal conductivity mica tape. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 SEM image showing the three-dimensional thermal conductive network formed by hexagonal boron nitride in the mica paper layer in Example 1;

[0026] Figure 2 The SEM cross-sectional view of the multi-medium synergistically modified high thermal conductivity mica tape of the present invention is shown;

[0027] Figure 3 A schematic structural diagram of a multi-medium synergistically modified high thermal conductivity mica tape of the present invention is shown, wherein 1 represents a three-dimensional thermal conductive network mica paper layer, 2 represents a reinforcing material layer, and 3 represents an adhesive layer. DETAILED DESCRIPTION

[0028] Specific implementation method 1: Figure 3 As shown, in this embodiment, a multi-medium synergistically modified high thermal conductivity mica tape comprises a three-dimensional thermal conductive network mica paper layer 1, two layers of reinforcing material layers 2 and an adhesive layer 3, wherein the three-dimensional thermal conductive network mica paper layer 1 is arranged between the two layers of reinforcing material layers 2, and the addition amount of the three-dimensional thermal conductive network mica paper layer 1 is 130-160 g / m 2 The adhesive layer 3 is arranged between the three-dimensional thermal conductive network mica paper layer 1 and the reinforcing material layer 2;

[0029] The three-dimensional thermal conductive network mica paper layer 1 is composed of mica flakes and high thermal conductive fillers, wherein the mica flakes are composed of mica flakes smaller than 60 mesh, mica flakes between 60 and 80 mesh, and mica flakes between 80 and 200 mesh, and the mass ratio of the mica flakes smaller than 60 mesh, the mica flakes between 60 and 80 mesh, and the mica flakes between 80 and 200 mesh is (20 to 30): (45 to 60): (5 to 10), and the addition amount of the high thermal conductive filler is 25% of the total mass of the mica flakes;

[0030] The reinforcing material layer 2 is electrical grade glass cloth, and the addition amount is 16-30g / m 2 ;

[0031] The adhesive layer 3 is composed of epoxy resin, curing agent, accelerator and high thermal conductivity filler, and the mass fraction of the high thermal conductivity filler is 6%, 12%, 18%, 24% or 30%;

[0032] The high thermal conductivity fillers in the three-dimensional thermal conductive network mica paper layer 1 and the adhesive layer 3 are both hexagonal boron nitride.

[0033] Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that the hexagonal boron nitride is composed of flake hexagonal boron nitride with a particle size of 0.5 to 10 μm and spherical boron nitride with a particle size of 20 to 60 μm.

[0034] The other steps are the same as those in the first specific implementation.

[0035] Specific embodiment three: This embodiment differs from specific embodiment one or two in that the mass ratio of the epoxy resin, curing agent and accelerator is (90-100): (70-90): (0.1-2), the epoxy resin is E51 type epoxy resin, the curing agent is methyl hexahydrophthalic anhydride, and the accelerator is DMP-30.

[0036] The other steps are the same as those in the first or second embodiment.

[0037] Specific implementation method 4: This implementation method is a method for preparing a multi-medium synergistically modified high thermal conductivity mica tape, which is carried out according to the following steps:

[0038] Step S1: preparing a three-dimensional thermal conductive network mica paper layer;

[0039] The mica slurry is mixed with a high thermal conductivity filler dispersion, and then subjected to ultrasonic and mechanical stirring, and then vacuum filtration and drying to obtain a three-dimensional thermal conductive network mica paper layer, wherein the high thermal conductivity filler in the high thermal conductivity filler dispersion accounts for 25% of the mass of mica flakes in the mica slurry;

[0040] Step S2: preparing an adhesive containing a high thermal conductive filler;

[0041] A high thermal conductive filler, an epoxy resin and methyl hexahydrophthalic anhydride are mixed, mechanically stirred and ultrasonically dispersed, and then a promoter is added, and then fully stirred under a vacuum environment to obtain an adhesive containing a high thermal conductive filler, wherein the mass fraction of the high thermal conductive filler in the adhesive containing the high thermal conductive filler is 6%, 12%, 18%, 24% or 30%;

[0042] Step S3: preparing a multi-medium synergistically modified high thermal conductivity mica tape;

[0043] Under the temperature condition of 50-80°C, the adhesive containing high thermal conductive filler obtained in step S2 is applied to the two surfaces of the three-dimensional thermal conductive network mica paper layer obtained in step S1, and then the adhesive containing high thermal conductive filler is applied to one surface of the reinforcing material layer, and then the three-dimensional thermal conductive network mica paper layer is placed between the two surfaces of the two reinforcing material layers dipped with the adhesive, and then placed in a vacuum oven for full impregnation under vacuum pressure, and finally hot-pressed for 10-50 minutes under the temperature condition of 60-90°C and the pressure condition of 0.5-5MPa to obtain a multi-medium synergistically modified high thermal conductive mica tape with a complete three-dimensional thermal conductive network, wherein the mass ratio of the three-dimensional thermal conductive network mica paper layer to the reinforcing material layer in the multi-medium synergistically modified high thermal conductive mica tape is (130-160): (16-30).

[0044] Specific implementation method five: The difference between this implementation method and specific implementation method four is that the mica slurry is prepared according to the following steps: mica flakes are added into deionized water and mixed thoroughly to obtain mica slurry, wherein the mass fraction of the mica flakes is 8-20%.

[0045] The other steps are the same as those in the fourth embodiment.

[0046] Specific embodiment 6: The difference between this embodiment and specific embodiment 4 or 5 is that the high thermal conductivity filler dispersion is prepared according to the following steps: adding the high thermal conductivity filler into distilled water, and ultrasonically dispersing for 20 to 100 minutes to obtain the high thermal conductivity filler dispersion.

[0047] The other steps are the same as those in the fourth or fifth embodiment.

[0048] Specific embodiment 7: The difference between this embodiment and any one of specific embodiments 4 to 6 is that the mechanical stirring time in step S1 is 5 to 20 minutes, and the drying temperature is 80 to 130°C.

[0049] The other steps are the same as those in Specific Embodiments 4 to 6.

[0050] Specific embodiment eight: The difference between this embodiment and specific embodiments four to seven is that the time of mechanical stirring and ultrasonic dispersion in step S2 is 300 to 800 minutes, and the time of stirring under vacuum environment is 100 to 140 minutes.

[0051] The other steps are the same as those in Specific Embodiments 4 to 7.

[0052] Specific embodiment 9: The difference between this embodiment and any one of specific embodiments 4 to 8 is that the time of immersion under vacuum pressure in step S3 is 60 to 120 minutes.

[0053] The other steps are the same as those in Specific Embodiments 4 to 8.

[0054] Specific implementation method ten: This implementation method is an application of a high thermal conductivity mica tape modified by multi-medium synergistic modification, and the application of the high thermal conductivity mica tape modified by multi-medium synergistic modification in the main insulation of the stator winding of a large-capacity high-voltage motor.

[0055] The following examples are used to verify the beneficial effects of the present invention:

[0056] Example 1: A method for preparing a multi-medium synergistically modified high thermal conductivity mica tape, comprising the following steps:

[0057] Step S1: preparing a three-dimensional thermal conductive network mica paper layer;

[0058] Weigh a certain mass of mica flakes, wherein the mass fraction of mica flakes smaller than 60 meshes is 30%, the mass fraction of mica flakes between 60 and 80 meshes is 60%, and the mass fraction of mica flakes larger than 80 meshes is 10%; put the mica flakes into a beaker, add 1000 mL of deionized water, stir and mix thoroughly with a glass rod to obtain a mica slurry, wherein the mass fraction of mica flakes in the mica slurry is 20%;

[0059] Weighing high thermal conductive filler hexagonal boron nitride (h-BN) according to 25% of the mass fraction of mica flakes, put it into a beaker, and then add 500 mL of distilled water; and fixing the beaker in an ultrasonic disperser, and then adding distilled water in the ultrasonic disperser for ultrasonic dispersion for 40 minutes, stirring with a power agitator during the ultrasonic process to fully mix the high thermal conductive filler and the mica slurry to obtain a hexagonal boron nitride dispersion;

[0060] First, pour 2000mL of distilled water into the barrel of vacuum-assisted filtration, then pour the mica slurry into the barrel, use a porous homogenizing plate to ultrasonically and stir the mica suspension in the barrel for 15 minutes, open the drain valve after stirring evenly, close the valve after the water is drained, and open the vacuum exhaust valve and the vacuum pump switch at the same time to vacuum filter and drain water to reduce the moisture of the paper sheet, then take it out and put it into a vacuum drying oven at 100°C for drying to obtain a three-dimensional thermal conductive network mica paper layer;

[0061] Step S2: preparing an adhesive containing a high thermal conductive filler;

[0062] The high thermal conductive filler, E51 epoxy resin and curing agent methyl hexahydrophthalic anhydride were mixed in a beaker, mechanically stirred and ultrasonically dispersed for 600 minutes, and then the accelerator DMP-30 was added. Then, after stirring for 120 minutes under a vacuum environment, the bubbles in the system were removed to obtain an adhesive containing a high thermal conductive filler, wherein the mass fraction of the high thermal conductive filler was 6%;

[0063] Step S3: preparing a multi-medium synergistically modified high thermal conductivity mica tape;

[0064] On a coating platform, an adhesive containing a high thermal conductivity filler is applied to the two surfaces of the three-dimensional thermal conductive network mica paper layer on a heating plate at 60°C. Since the mica paper is loose and porous, the adhesive will pre-impregnate the entire mica paper layer; then the adhesive containing the high thermal conductivity filler is applied to one surface of the reinforcing material layer, and then the three-dimensional thermal conductive network mica paper layer is placed between the two surfaces of the two reinforcing material layers dipped with the adhesive, and then placed in a vacuum oven for immersion under vacuum pressure for 60 minutes, and finally hot-pressed at a temperature of 65°C and a pressure of 5MPa for 50 minutes, the adhesive will soak the entire composite mica tape, and the excess adhesive will be squeezed out. At the same time, the spherical thermal conductive filler in the adhesive will be reserved in the gap of the glass fiber cloth, so as to obtain a multi-medium synergistically modified high thermal conductive mica tape with a complete three-dimensional thermal conductive network, and the mass ratio of the three-dimensional thermal conductive network mica paper layer to the reinforcing material layer in the multi-medium synergistically modified high thermal conductive mica tape is 130:20.

[0065] The mass ratio of the epoxy resin, the curing agent and the accelerator is 100:90:1.

[0066] Figure 2 The SEM cross-sectional view of the multi-medium synergistically modified high thermal conductivity mica tape of the present invention is shown; Figure 2 As shown, hexagonal boron nitride is pre-placed between the mica paper layers and in the holes, forming a heat conduction path inside the mica paper; secondly, the spherical boron nitride in the adhesive is reserved in the glass cloth during the impregnation process, which increases the heat conduction between the mica paper layer and the glass cloth layer.

[0067] Example 2: In this example, the amount of hexagonal boron nitride, a high thermal conductivity filler, added is 12% of the mass fraction of the adhesive. Other experimental conditions are the same as those in Example 1.

[0068] Example 3: In this example, the amount of hexagonal boron nitride, a high thermal conductivity filler, added is 18% of the mass fraction of the adhesive. Other experimental conditions are the same as those in Example 1.

[0069] Example 4: In this example, the amount of hexagonal boron nitride, a high thermal conductive filler, added is 24% of the mass fraction of the adhesive. Other experimental conditions are the same as those in Example 1.

[0070] Example 5: In this example, the amount of hexagonal boron nitride, a high thermal conductivity filler, added is 30% of the mass fraction of the adhesive. Other experimental conditions are the same as those in Example 1.

[0071] Example 7: In this example, high thermal conductivity hexagonal boron nitride is not pre-placed in the mica paper and high thermal conductivity spherical boron nitride is not doped in the adhesive. Other experimental conditions are the same as those in Example 1.

[0072] Table 1 shows the performance parameters of the high thermal conductivity mica tapes in Examples 1-7;

[0073] Table 1

[0074]

[0075]

[0076] It can be seen from the data in Table 1 that the high thermal conductivity mica tape modified by multi-medium synergistically in the present invention significantly improves the thermal conductivity and dielectric strength of the mica tape. At the same time, with the increase of the content of spherical boron nitride reserved in the glass fiber cloth, the thermal conductivity of the mica tape increases, up to 0.732W / m·K; the dielectric loss of the mica tape decreases, less than 1%. It can be seen that the high thermal conductivity mica tape modified by multi-medium synergistically prepared by the present invention has excellent thermal conductivity and dielectric properties, which can improve the stability of large generators during operation and extend the service life of the motor.

Claims

1. A multi-medium synergistically modified high thermal conductivity mica tape, characterized in that The multi-medium synergistically modified high thermal conductivity mica tape comprises a three-dimensional thermal conductive network mica paper layer (1), two layers of reinforcing material layers (2) and an adhesive layer (3), wherein the three-dimensional thermal conductive network mica paper layer (1) is arranged between the two layers of reinforcing material layers (2), and the addition amount of the three-dimensional thermal conductive network mica paper layer (1) is 130-160 g / m 2 ; The adhesive layer (3) is arranged between the three-dimensional thermal conductive network mica paper layer (1) and the reinforcing material layer (2); The three-dimensional thermal conductive network mica paper layer (1) is composed of mica flakes and high thermal conductive fillers, wherein the mica flakes are composed of mica flakes smaller than 60 mesh, mica flakes between 60 and 80 mesh, and mica flakes between 80 and 200 mesh, and the mass ratio of the mica flakes smaller than 60 mesh, the mica flakes between 60 and 80 mesh, and the mica flakes between 80 and 200 mesh is (20 to 30): (45 to 60): (5 to 10), and the addition amount of the high thermal conductive filler is 25% of the total mass of the mica flakes; The reinforcing material layer (2) is electrical grade glass cloth, with an addition amount of 16-30 g / m 2 ; The adhesive layer (3) is composed of epoxy resin, curing agent, accelerator and high thermal conductivity filler, and the mass fraction of the high thermal conductivity filler is 6%, 12%, 18%, 24% or 30%; The high thermal conductivity fillers in the three-dimensional thermal conductive network mica paper layer (1) and the adhesive layer (3) are both hexagonal boron nitride.

2. The multi-medium synergistically modified high thermal conductivity mica tape according to claim 1, characterized in that The hexagonal boron nitride is composed of flake hexagonal boron nitride with a particle size of 0.5 to 10 μm and spherical boron nitride with a particle size of 20 to 60 μm.

3. The multi-medium synergistically modified high thermal conductivity mica tape according to claim 1, characterized in that The mass ratio of the epoxy resin, curing agent and accelerator is (90-100): (70-90): (0.1-2), the epoxy resin is E51 epoxy resin, the curing agent is methyl hexahydrophthalic anhydride, and the accelerator is DMP-30.

4. A method for preparing a multi-medium synergistically modified high thermal conductivity mica tape as described in any one of claims 1 to 3, characterized in that The preparation method is carried out according to the following steps: Step S1: preparing a three-dimensional thermal conductive network mica paper layer; The mica slurry is mixed with a high thermal conductivity filler dispersion, and then subjected to ultrasonic and mechanical stirring, and then vacuum filtration and drying to obtain a three-dimensional thermal conductive network mica paper layer, wherein the high thermal conductivity filler in the high thermal conductivity filler dispersion accounts for 25% of the mass of mica flakes in the mica slurry; Step S2: preparing an adhesive containing a high thermal conductive filler; A high thermal conductive filler, an epoxy resin and methyl hexahydrophthalic anhydride are mixed, mechanically stirred and ultrasonically dispersed, and then a promoter is added, and then fully stirred under a vacuum environment to obtain an adhesive containing a high thermal conductive filler, wherein the mass fraction of the high thermal conductive filler in the adhesive containing the high thermal conductive filler is 6%, 12%, 18%, 24% or 30%; Step S3: preparing a multi-medium synergistically modified high thermal conductivity mica tape; Under the temperature condition of 50-80°C, the adhesive containing high thermal conductive filler obtained in step S2 is applied to the two surfaces of the three-dimensional thermal conductive network mica paper layer obtained in step S1, and then the adhesive containing high thermal conductive filler is applied to one surface of the reinforcing material layer, and then the three-dimensional thermal conductive network mica paper layer is placed between the two surfaces of the two reinforcing material layers dipped with the adhesive, and then placed in a vacuum oven for full impregnation under vacuum pressure, and finally hot-pressed for 10-50 minutes under the temperature condition of 60-90°C and the pressure condition of 0.5-5MPa to obtain a multi-medium synergistically modified high thermal conductive mica tape with a complete three-dimensional thermal conductive network, wherein the mass ratio of the three-dimensional thermal conductive network mica paper layer to the reinforcing material layer in the multi-medium synergistically modified high thermal conductive mica tape is (130-160): (16-30).

5. The method for preparing a multi-medium synergistically modified high thermal conductivity mica tape according to claim 4, characterized in that The mica slurry is prepared according to the following steps: mica flakes are added into deionized water and mixed thoroughly to obtain mica slurry, wherein the mass fraction of the mica flakes is 8-20%.

6. The method for preparing a multi-medium synergistically modified high thermal conductivity mica tape according to claim 4, characterized in that The high thermal conductivity filler dispersion is prepared according to the following steps: adding the high thermal conductivity filler into distilled water, and ultrasonically dispersing for 20 to 100 minutes to obtain the high thermal conductivity filler dispersion.

7. The method for preparing a multi-medium synergistically modified high thermal conductivity mica tape according to claim 4, characterized in that In step S1, the mechanical stirring time is 5 to 20 minutes, and the drying temperature is 80 to 130°C.

8. The method for preparing a multi-medium synergistically modified high thermal conductivity mica tape according to claim 4, characterized in that In step S2, the time for mechanical stirring and ultrasonic dispersion is 300 to 800 minutes, and the time for stirring under vacuum environment is 100 to 140 minutes.

9. The method for preparing a multi-medium synergistically modified high thermal conductivity mica tape according to claim 4, characterized in that The time of immersion under vacuum pressure in step S3 is 60 to 120 minutes.

10. Application of a multi-medium synergistically modified high thermal conductivity mica tape as claimed in any one of claims 1 to 3, characterized in that The multi-medium synergistically modified high thermal conductivity mica tape is used in the main insulation of the stator winding of a large-capacity high-voltage motor.

Images