High-temperature-resistant heating warning insulating tape and preparation method thereof

Abstract

The invention relates to the technical field of insulated rubber tapes, and particularly discloses a high-temperature-resistant heating warning insulated rubber tape and a preparation method thereof.The preparation method comprises the steps that a polyimide film is subjected to surface treatment, and one face of the polyimide film is coated with a temperature developing layer; the preparation method comprises the following steps: mixing aluminum oxide, silicon dioxide and urea, performing high-speed ball milling and microwave treatment, and then modifying by adopting a surfactant to obtain a modified filler; preparing a coating liquid, wherein the coating liquid comprises the following components: 40 parts of organic silicon rubber, 50-60 parts of silicon resin, 80-160 parts of a solvent, 10-18 parts of a modified filler, 1-2 parts of a cross-linking agent and 0.1-0.5 part of a catalyst; and uniformly coating the organic silicon pressure-sensitive adhesive coating liquid on the other surface of the polyimide film to obtain the adhesive layer. According to the prepared high-temperature-resistant heating warning insulating tape, the high-temperature heating phenomenon can be warned through the temperature developing layer, potential risks can be found in time, the heat resistance and viscosity of the insulating tape are improved through the modified filler, the preparation method is simple and easy to operate, and the raw materials are low in cost and easy to obtain.

Description

Technical Field

[0001] The present invention relates to the technical field of insulating tapes, and in particular to a high-temperature resistant heat-generating warning insulating tape and a preparation method thereof. Background Art

[0002] Insulating tapes are used for electrical insulation, and their main functions are to prevent leakage risks and provide insulation protection. They are widely used in the wrapping of wire connection points, the insulation treatment of electrical components, and the insulation and damage repair of various resistance elements. For example, in wire joint winding, motors and electronic components such as transformers, motors, capacitors, and voltage regulators, insulating tapes provide indispensable insulation protection. Insulating tapes have excellent insulation voltage resistance, flame retardancy, etc. However, there are some problems when using insulating tapes: when using insulating tapes, multiple layers of winding are required, and multiple layers of winding are likely to cause the heat generated by the winding protection to accumulate without being dissipated. If the heat is not dissipated in time, the temperature will rise. If the high-temperature phenomenon cannot be detected in time, it is easy to cause the high-temperature melting of electrical equipment or parts, resulting in power outages and accidents.

[0003] Compared with traditional insulating tapes, the temperature-sensitive color-changing warning insulating tape composed of multiple layers has more advantages in terms of function. For example, it can change color with the change of temperature, thus providing an intuitive temperature change warning effect. The Chinese patent application with publication number CN107151536 A discloses a heat-dissipating and temperature-displaying electrical insulating tape, which can display the temperature change at the winding protection part and has good heat dissipation and heat conduction capabilities. However, the temperature-sensitive color-changing warning insulating tape still has deficiencies in terms of high-temperature resistance, adhesiveness, etc., and needs to be further improved. At present, most of them improve the high-temperature resistance of insulating tapes by adding heat-conducting fillers and heat-resistant fillers. The high-temperature resistance increases with the increase of the addition amount of the fillers. However, when the addition amounts of the heat-conducting fillers and heat-resistant fillers are relatively large, it will affect the adhesiveness of the insulating tape. Summary of the Invention

[0004] Aiming at the above deficiencies, the present invention provides a preparation method of a high-temperature resistant heat-generating warning insulating tape. The prepared insulating tape has characteristics such as heat-generating warning, high-temperature resistance, and good adhesiveness. The specific technical solutions are as follows: A preparation method of a high-temperature resistant heat-generating warning insulating tape, the insulating tape is a multi-layer structure, and sequentially includes a temperature display layer, a polyimide matrix layer, and an adhesive layer from top to bottom. The preparation method includes the following steps: (1) Perform surface treatment on a polyimide film substrate, and coat a temperature display layer on one side of the polyimide film; (2) Mix alumina, silica, and urea by high-speed ball milling at a weight ratio of 1:0.4 - 0.6:0.05 - 0.1, and then perform microwave treatment to obtain a mixed filler. Add the mixed filler into an ethanol solution to obtain a suspension. Add a surfactant to the suspension, perform ultrasonic oscillation, filter, and dry to obtain a modified filler. (3) Prepare a silicone pressure-sensitive adhesive coating solution, which includes the following components by weight: 40 parts of silicone rubber, 50 - 60 parts of silicone resin, 80 - 160 parts of solvent, 10 - 18 parts of modified filler, 1 - 2 parts of crosslinking agent, and 0.1 - 0.3 parts of catalyst. (4) Uniformly coat the silicone pressure-sensitive adhesive coating solution prepared in step (3) on the other side of the polyimide film obtained in step (1), and keep it in an oven at 140 - 160 °C for 4 - 6 min to obtain an adhesive layer, thus completing the preparation of the high-temperature resistant heat-generating warning insulating tape.

[0005] The working principle of the technical solution of the present invention is as follows: On the one hand, by setting a temperature color display layer on the surface of the substrate, it can warn of high-temperature heat-generating phenomena, which is beneficial to timely discovering potential dangers. On the other hand, adding a modified filler to the silicone pressure-sensitive adhesive coating solution improves the heat dissipation and high-temperature resistance of the tape. Urea is used to modify the filler composed of alumina and silica. First, the three are subjected to high-speed ball milling, which not only makes the three mix evenly, but more importantly, improves the reaction activity of each substance. Then, combined with microwave treatment, it promotes the nitrogen doping of alumina and silica by urea, improving the thermal conductivity and heat resistance of the filler, thereby enhancing the heat dissipation and high-temperature resistance of the insulating tape. Further, a surfactant is used to perform surface modification on the mixed filler, enhancing the wetting of the adhesive to the mixed filler, improving the combination of the mixed filler and the adhesive, improving the dispersion and stability of the mixed filler in the adhesive, reducing the influence of the filler on the adhesiveness, and improving the adhesiveness of the insulating tape.

[0006] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, in step (2), the microwave treatment process parameters are: microwave power is 1000 - 1500 W, and the treatment time is 10 - 30 min.

[0007] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, in step (2), the ball milling speed is 1000 - 1500 rpm, and ball milling is performed for 2 - 4 h.

[0008] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, the surfactant is composed of dodecylphenol polyoxyethylene ether, sodium stearate and silane coupling agent. The mass ratio of dodecylphenol polyoxyethylene ether, sodium stearate and silane coupling agent is 1-2:1-2:3-5, and the addition amount of the surfactant is 3-8% of the mass of the mixed filler. The surfactant composed of the three of dodecylphenol polyoxyethylene ether, sodium stearate and silane coupling agent is used to modify the mixed filler to form an organic-inorganic hybrid network structure, improve the dispersibility of the mixed filler in the glue, and improve the combination of the mixed filler and the glue.

[0009] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, in the step (2), the ultrasonic oscillation power is 800-1000W, the ultrasonic oscillation time is 30min-60min, and the ultrasonic frequency is 30-50KHz.

[0010] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, in the step (3), the specific steps of preparing the organosilicon pressure-sensitive adhesive coating solution include: S1. Mix 40 parts of organosilicon rubber, 50-60 parts of silicone resin, 0.1-0.3 parts of catalyst and 60-110 parts of solvent, and then stir and react at 95-105°C for 3-4h to obtain an organosilicon pressure-sensitive adhesive; S2. Disperse 10-18 parts of modified filler into 10-30 parts of solvent to obtain a modified filler dispersion; S3. Add 1-2 parts of cross-linking agent to 10-20 parts of solvent to dissolve, and prepare a cross-linking agent solution; S4. Add the modified filler dispersion obtained in step S2 and the cross-linking agent solution obtained in step S3 to the organosilicon pressure-sensitive adhesive obtained in step S1, and stir and mix at high speed to obtain an organosilicon pressure-sensitive adhesive coating solution.

[0011] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, the cross-linking agent is dibenzoyl peroxide, and the catalyst is dibutyltin dilaurate.

[0012] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, the organosilicon rubber is hydroxyl-terminated silicone rubber with a molecular weight of 100,000-300,000; the silicone resin is MQ silicone resin with a molecular weight of 3000-6000.

[0013] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, the particle size of the alumina is 300-800nm, and the particle size of the silica is 20-35nm.

[0014] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, the thickness of the polyimide film is 15-30 μm, the thickness of the adhesive layer is 10-30 μm, and the surface treatment is corona treatment or plasma surface treatment.

[0015] Preferably, in the preparation method of the above-mentioned high-temperature resistant heat-generating warning insulating tape, the preparation of the temperature color display layer includes: mixing a thermochromic powder, a binder, and a dispersant to prepare a temperature color display slurry, and coating the temperature color display slurry on the surface of the polyimide film and curing to obtain the temperature color display layer.

[0016] On the other hand, the present invention also provides a high-temperature resistant heat-generating warning insulating tape, which is prepared by the above-mentioned preparation method.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The high-temperature resistant heat-generating warning insulating tape prepared by the present invention can warn of high-temperature heat-generating phenomena through the temperature color display layer, which is beneficial to timely discovering potential dangers. The heat resistance and viscosity of the insulating tape are improved through modified fillers, and it also has good chemical corrosion resistance. The preparation method is simple and easy to operate, and the raw materials are cheap and easily available.

[0018] 2. In the preparation method of the high-temperature resistant heat-generating warning insulating tape of the present invention, urea combined with high-speed ball milling and microwave treatment is used to modify the filler composed of alumina and silica, improving the thermal conductivity and heat resistance of the filler, thereby enhancing the heat resistance of the insulating tape. Further, a surfactant is used to perform surface modification on the mixed filler to form an organic-inorganic hybrid network structure, enhancing the infiltration of the adhesive to the mixed filler, improving the combination of the mixed filler and the adhesive, reducing the influence of the filler on the adhesiveness, and improving the adhesiveness of the insulating tape. Specific Embodiments

[0019] The following describes the specific embodiments of the present invention in detail, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments. Unless otherwise defined, all professional terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in the present invention can be obtained through the market or can be prepared by existing methods.

[0020] Example 1

[0021] A high-temperature resistant heat-generating warning insulating tape, the insulating tape is a multi-layer structure, and sequentially includes a temperature color display layer, a polyimide matrix layer, and an adhesive layer from top to bottom, and the adhesive layer is an organosilicon pressure-sensitive adhesive layer.

[0022] A preparation method of a high-temperature resistant heat-generating warning insulating tape, comprising the following steps: (1) Prepare a modified filler: Mix alumina (D50 = 0.8 μm), silica (D50 = 20 nm), and urea in a weight ratio of 1:0.5:0.08, ball mill for 3 h at a ball mill speed of 1200 rpm, and then treat with a microwave power of 1200 W for 20 min to obtain a mixed filler; Add the mixed filler to an ethanol aqueous solution with a volume concentration of 80% to obtain a suspension, and the weight ratio of the mixed filler to the ethanol aqueous solution is 1:10. Add a surfactant composed of dodecylphenol polyoxyethylene ether, sodium stearate, and γ-aminopropyltriethoxysilane to the suspension. The mass ratio of dodecylphenol polyoxyethylene ether, sodium stearate, and γ-aminopropyltriethoxysilane is 1.5:1.5:4, and the addition amount of the surfactant is 5% of the mass of the mixed filler. Perform ultrasonic oscillation with an ultrasonic oscillation power of 1000 W, an ultrasonic oscillation time of 1 h, and an ultrasonic frequency of 40 KHz, filter, and place in a vacuum drying oven at 80 °C for vacuum drying to obtain a modified filler; (2) Prepare a silicone pressure-sensitive adhesive coating solution: The silicone pressure-sensitive adhesive coating solution includes the following components by weight: 40 parts of silicone rubber (107 silicone rubber with a molecular weight of 200,000), 55 parts of MQ silicone resin (molecular weight of 4000), 120 parts of xylene, 14 parts of modified filler, 1.5 parts of dibenzoyl peroxide, and 0.2 parts of dibutyltin dilaurate; (3) Perform corona treatment on both sides of a 25-μm-thick polyimide film substrate. Coat a temperature-sensitive color-developing slurry on one side of the polyimide film. The slurry is mainly composed of a temperature-sensitive color-changing powder and a binder. The temperature-sensitive color-changing powder can select different temperature-sensitive color-developing powders according to the usage scenario, or a multi-layer structure can be set with reference to the prior art to display different temperature ranges. The specific composition of the temperature-sensitive color-developing slurry in this embodiment by weight is: 50 parts of high-temperature resistant epoxy resin, 3 parts of temperature-sensitive color-changing powder, 5 parts of amine curing agent, 0.6 parts of BYK-110 dispersant, and 20 parts of xylene. Add the temperature-sensitive color-changing powder to xylene and perform ultrasonic dispersion evenly, then add the dispersant and epoxy resin and grind and disperse evenly, and finally add the curing agent and stir evenly to obtain the temperature-sensitive color-developing slurry. Uniformly coat the temperature-sensitive color-developing slurry on one side of the polyimide film, and then cure at 100 °C for 2 h to obtain a temperature-sensitive color-developing layer with a thickness of 25 μm; (4) Uniformly coat the silicone pressure-sensitive adhesive coating solution prepared in step (2) on the other side of the polyimide film obtained in step (3), and keep it warm in an oven at 150 °C for 5 min to obtain an adhesive layer with a thickness of 22 μm, thus completing the preparation of the high-temperature resistant heat-generating warning insulating tape.

[0023] The specific steps for preparing the silicone pressure-sensitive adhesive coating solution include: S1. Mix 40 parts of silicone rubber, 55 parts of silicone resin, 0.2 part of dibutyltin dilaurate, and 80 parts of xylene, and then stir and react at 100 °C for 4 h to obtain a silicone pressure-sensitive adhesive. S2. Ultrasonically disperse 14 parts of modified filler evenly into 25 parts of xylene to obtain a modified filler dispersion. S3. Dissolve 1.5 parts of benzoyl peroxide in 15 parts of xylene to prepare a benzoyl peroxide solution. S4. Add the modified filler dispersion obtained in step S2 and the benzoyl peroxide solution obtained in step S3 to the silicone pressure-sensitive adhesive obtained in step S1, stir and mix evenly at high speed, and stir at a rotation speed of 1500 r / min for 2 h to obtain a silicone pressure-sensitive adhesive coating solution.

[0024] Example 2

[0025] A high-temperature resistant heat-generating warning insulating tape, the insulating tape is a multi-layer structure, and sequentially includes a temperature color display layer, a polyimide matrix layer, and an adhesive layer from top to bottom, and the adhesive layer is a silicone pressure-sensitive adhesive layer.

[0026] A preparation method of a high-temperature resistant heat-generating warning insulating tape, comprising the following steps: (1) Prepare modified filler: Mix alumina (D50 = 0.8 μm), silica (D50 = 20 nm), and urea according to a weight ratio of 1:0.4:0.05, ball mill at a ball mill rotation speed of 1300 rpm for 2.5 h, and then treat at a microwave power of 1000 W for 30 min to obtain a mixed filler; add the mixed filler to an ethanol aqueous solution with a volume concentration of 80% to obtain a suspension, and the weight ratio of the mixed filler to the ethanol aqueous solution is 1:10. Add a surfactant composed of dodecylphenol polyoxyethylene ether, sodium stearate, and γ-aminopropyltriethoxysilane to the suspension. The mass ratio of dodecylphenol polyoxyethylene ether, sodium stearate, and γ-aminopropyltriethoxysilane is 1:1.8:5, and the addition amount of the surfactant is 5% of the mass of the mixed filler. Perform ultrasonic oscillation, the ultrasonic oscillation power is 1000 W, the ultrasonic oscillation time is 1 h, the ultrasonic frequency is 40 KHz, filter, and place in a vacuum drying oven at 80 °C for vacuum drying to obtain the modified filler. (2) Prepare a silicone pressure-sensitive adhesive coating solution: The silicone pressure-sensitive adhesive coating solution includes the following components by weight: 40 parts of silicone rubber (107 silicone rubber with a molecular weight of 200,000), 50 parts of MQ silicone resin (molecular weight of 4000), 120 parts of xylene, 15 parts of modified filler, 1.5 parts of benzoyl peroxide, and 0.18 part of dibutyltin dilaurate. (3) The two sides of a polyimide film substrate with a thickness of 25 μm are subjected to corona treatment. A temperature-sensitive color-developing slurry is coated on one side of the polyimide film. The slurry is mainly composed of a thermochromic powder and a binder. The thermochromic powder can be selected as different temperature-sensitive color-developing powders according to the usage scenario, or a multi-layer structure can be set to display different temperature ranges. The specific composition of the temperature-sensitive color-developing slurry in this embodiment is as follows by weight: 50 parts of epoxy resin, 3 parts of thermochromic powder, 5 parts of curing agent, 0.6 part of BYK-110 dispersant, and 20 parts of xylene. The thermochromic powder is added to xylene and ultrasonically dispersed evenly, then the dispersant and epoxy resin are added and ground and dispersed evenly, and finally the curing agent is added and stirred evenly to obtain the temperature-sensitive color-developing slurry. The temperature-sensitive color-developing slurry is evenly coated on one side of the polyimide film, and then cured at 100 °C for 2 h to obtain a temperature-sensitive color-developing layer with a thickness of 25 μm. (4) The silicone pressure-sensitive adhesive prepared in step (2) is evenly coated on the other side of the polyimide film obtained in step (3), and kept warm in an oven at 150 °C for 5 min to obtain an adhesive layer with a thickness of 22 μm, thus completing the preparation of the high-temperature resistant heat-generating warning insulating tape.

[0027] The specific steps for preparing the silicone pressure-sensitive adhesive coating solution include: S1. 40 parts of silicone rubber, 50 parts of silicone resin, 0.18 part of dibutyltin dilaurate and 80 parts of xylene are mixed, and then stirred and reacted at 100 °C for 4 h to obtain a silicone pressure-sensitive adhesive. S2. 15 parts of modified filler are ultrasonically dispersed evenly into 25 parts of xylene to obtain a modified filler dispersion. S3. 1.5 parts of dibenzoyl peroxide are added to 15 parts of xylene for dissolution to obtain a dibenzoyl peroxide solution. S4. The modified filler dispersion obtained in step S2 and the dibenzoyl peroxide solution obtained in step S3 are added to the silicone pressure-sensitive adhesive obtained in step S1, and stirred and mixed evenly at a high speed, stirred at a speed of 1500 r / min for 2 h to obtain a silicone pressure-sensitive adhesive coating solution.

[0028] Comparative Example 1 The difference between this comparative example and Example 1 is that: urea is not added in step (1), and the others are the same as in Example 1.

[0029] Comparative Example 2 The difference between this comparative example and Example 1 is that: the ball milling speed in step (1) is 400 rpm and ball milling is carried out for 5 h, and the others are the same as in Example 1.

[0030] Comparative Example 3 The difference between this comparative example and Example 1 is that: in step (1), the microwave is treated at a microwave power of 700 W for 60 min, and the others are the same as in Example 1.

[0031] Comparative Example 4 This comparative example is different from Example 1 in that: in step (1), the surfactant is γ-aminopropyltriethoxysilane, and the others are the same as in Example 1.

[0032] Test the performance of the insulating tapes in the examples and comparative examples: 180° peel strength: Refer to Method 1 in the standard GB / T 2792-2014 to test the 180° peel strength of the insulating tapes in the examples and comparative examples from the stainless steel plate, with a peel speed of 300 mm / min; Initial tack: Refer to Method A in the standard GB / T 4852-2002 to test the initial tack performance of the insulating tape; High-temperature holding tack performance: Refer to the standard GB / T 4851-1998 to test the holding tack strength. Stick the polyimide tape on the stainless steel plate with an area of 25×25 mm 2 and roll it back and forth 3 times with a 2 kg pressure roller. After standing for 20 min, apply a shear force of 500 g to the polyimide tape and measure the time required for the polyimide tape to fall off the stainless steel plate in an oven at 280°C.

[0033] Test for high-temperature resistance: Refer to the method in the standard GB / T 2423.2-2008 to test the high-temperature performance. Set the temperature to 240°C, the exposure time to 30 min, and then take it out to test the 180° peel strength.

[0034] Table 1 shows the performance data of the insulating tapes in each group. It can be seen from the table that the insulating tape prepared by the present invention has high peel strength and high-temperature resistance, and good initial tack and high-temperature holding tack. There is no obvious difference in the peel strength at room temperature between Comparative Example 1 and Example 1. However, after the high-temperature resistance test, the peel strength retention rate of Example 1 is 96.2%, and that of Comparative Example 1 is 87.6%. The peel strength of Comparative Example 1 decreases significantly after the high-temperature test, indicating that using urea to modify the mixed filler can significantly improve the heat resistance of the insulating tape; comparing Example 1 with Comparative Examples 2-3, it can be seen that the ball milling parameters and microwave parameters will affect the modification effect of urea on the mixed filler, thereby affecting the high-temperature performance of the insulating tape. Comparing the performance data of Example 1 and Comparative Example 4, it can be known that using a surfactant composed of the compound of dodecylphenol polyoxyethylene ether, sodium stearate and γ-aminopropyltriethoxysilane for surface modification of the mixed filler is more conducive to improving the bonding between the mixed filler and the glue, and improving the viscosity and high-temperature resistance of the tape.

[0035] Table 1 Performance data of insulating tapes in each group

[0036] The foregoing description of the specific exemplary embodiments of the present invention is for purposes of illustration and exemplification. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many modifications and variations are possible in light of the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the invention and its practical applications, so that those skilled in the art can implement and utilize the various different exemplary embodiments of the invention, as well as various different selections and modifications. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for preparing a high temperature resistant heating warning insulating tape, characterized in that: The insulating tape is a multi-layer structure, which includes a temperature color development layer, a polyimide matrix layer, and an adhesive layer from top to bottom. The preparation method includes the following steps: (1) Surface treatment is performed on a polyimide film substrate, and a temperature color developing layer is coated on one side of the polyimide film; (2) Alumina, silica and urea are mixed in a weight ratio of 1:0.4-0.6:0.05-0.1, subjected to high-speed ball milling, and then subjected to microwave treatment to obtain a mixed filler; the mixed filler is added to an ethanol solution to obtain a suspension, a surfactant is added to the suspension, ultrasonically vibrated, filtered, and dried to obtain a modified filler; (3) preparing an organic silicone pressure-sensitive adhesive coating liquid, wherein the organic silicone pressure-sensitive adhesive coating liquid comprises the following components in parts by weight: 40 parts of organic silicone rubber, 50-60 parts of silicone resin, 80-160 parts of solvent, 10-18 parts of modified filler, 1-2 parts of cross-linking agent, and 0.1-0.3 parts of catalyst; (4) The silicone pressure-sensitive adhesive coating liquid obtained in step (3) is evenly coated on the other side of the polyimide film obtained in step (1), and kept in an oven at 140 to 160° C. for 4 to 6 minutes to obtain an adhesive layer, thereby completing the preparation of the high-temperature resistant heat warning insulating tape.

2. The method for preparing the high temperature resistant heating warning insulating tape according to claim 1, characterized in that: In the step (2), the microwave treatment process parameters are: microwave power is 1000-1500W, and the treatment time is 10-30min.

3. The method for preparing the high temperature resistant heating warning insulating tape according to claim 1, characterized in that: In the step (2), the ball milling speed is 1000-1500 rpm, and the ball milling time is 2-4 hours.

4. The method for preparing the high temperature resistant heating warning insulating tape according to claim 1, characterized in that: The surfactant is composed of dodecylphenol polyoxyethylene ether, sodium stearate and silane coupling agent, the mass ratio of dodecylphenol polyoxyethylene ether, sodium stearate and silane coupling agent is 1-2:1-2:3-5, and the added amount of the surfactant is 3-8% of the mass of the mixed filler.

5. The method for preparing the high temperature resistant heating warning insulating tape according to claim 1, characterized in that: In the step (2), the ultrasonic oscillation power is 800-1000W, the ultrasonic oscillation time is 1h-2h, and the ultrasonic frequency is 30-50KHz.

6. The method for preparing the high temperature resistant heating warning insulating tape according to claim 1, characterized in that: In step (3), the specific steps of preparing the silicone pressure-sensitive adhesive coating liquid include: S1. 40 parts of silicone rubber, 50-60 parts of silicone resin, 0.1-0.3 parts of catalyst and 60-110 parts of solvent are mixed, and then stirred at 95-105° C. for 3-4 hours to obtain a silicone pressure-sensitive adhesive; S2. Dispersing 10 to 18 parts of the modified filler into 10 to 30 parts of a solvent to obtain a modified filler dispersion; S3. 1 to 2 parts of a crosslinking agent are added to 10 to 20 parts of a solvent and dissolved to obtain a crosslinking agent solution; S4. Add the modified filler dispersion obtained in step S2 and the crosslinking agent solution obtained in step S3 to the organosilicon pressure-sensitive adhesive obtained in step S1, and stir and mix at high speed to obtain an organosilicon pressure-sensitive adhesive coating liquid.

7. The method for preparing the high temperature resistant heating warning insulating tape according to claim 1, characterized in that: The cross-linking agent is dibenzoyl peroxide, and the catalyst is dibutyltin dilaurate.

8. The method for preparing the high temperature resistant heating warning insulating tape according to claim 1, characterized in that: The thickness of the polyimide film is 15-30 μm, the thickness of the adhesive layer is 10-30 μm, and the surface treatment is corona treatment or plasma surface treatment.

9. The method for preparing the high temperature resistant heating warning insulating tape according to claim 1, characterized in that: The preparation of the temperature color developing layer includes: mixing the temperature color developing powder, the binder and the dispersant to prepare the temperature color developing slurry, coating the temperature color developing slurry on the surface of the polyimide film, and curing to obtain the temperature color developing layer.

10. A high temperature resistant heating warning insulating tape, characterized in that: The insulating tape is prepared by the preparation method according to any one of claims 1 to 9.

Images