Self-repairing super-hydrophobic modified insulation paper and preparation method thereof

Abstract

The invention discloses self-repairing super-hydrophobic modified insulation paper and a preparation method thereof, and belongs to the technical field of electrical insulation materials. The preparation method disclosed by the invention comprises the following steps: preparing an epoxy resin nanofiber capsule and super-hydrophobic modified nano aluminum oxide; in a stirring state, sequentially adding epoxy resin nanofiber capsules, super-hydrophobic modified nano aluminum oxide and a wet strength agent into the pure fiber slurry to obtain mixed insulation paper slurry; and carrying out post-treatment and hot-pressing treatment on the mixed insulation paper slurry to obtain the self-repairing super-hydrophobic modified insulation paper. The method disclosed by the invention solves the technical problem that the existing method is difficult to solve the problems of heat dissipation, damage repair and moisture-proof defects at the same time.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrical insulation materials, and particularly relates to a self-repairing super-hydrophobic modified insulation paper and a preparation method thereof. BACKGROUND

[0002] Insulation paper is an indispensable key material in power equipment (such as transformers, motors, etc.). With the development of power equipment towards large capacity, miniaturization and high voltage, the problem of internal heat accumulation is becoming increasingly serious. Overheating can accelerate the aging of insulation materials, leading to a decline in their insulation performance and ultimately causing equipment failure.

[0003] Traditional plant fiber insulation paper (such as kraft paper) has three major weaknesses: first, the thermal conductivity is low (usually below 0.2 W / (m•K)), which seriously hinders heat dissipation; second, under the action of long-term electric-thermal-mechanical stress, micro-cracks and other damages occur, which are irreversible and ultimately lead to insulation failure; third, the hydrophilicity of cellulose makes it easy to absorb moisture from the environment, leading to increased dielectric loss, decreased insulation resistance, and possibly causing water trees, threatening equipment safety.

[0004] In the prior art, there are studies on improving thermal conductivity by adding nano-alumina fillers or achieving self-repairing by introducing microcapsules. However, these solutions often have single functions, and the introduction of fillers may cause problems such as compatibility, mechanical performance decline or complex process. Therefore, how to simultaneously solve the problems of heat dissipation, damage repair and moisture prevention to prepare a comprehensive high-performance insulation paper is still a technical bottleneck that needs to be broken through in the field. SUMMARY

[0005] The purpose of the present application is to provide a self-repairing super-hydrophobic modified insulation paper and a preparation method thereof, to solve the technical problem that the existing method cannot simultaneously solve the problems of heat dissipation, damage repair and moisture prevention.

[0006] In order to achieve the above-mentioned purpose, the following technical solutions are adopted: The application discloses a preparation method of a self-repairing super-hydrophobic modified insulation paper, comprising the following steps: Preparation of epoxy resin nanofiber capsules and super-hydrophobic modified nano-alumina; Under stirring, the epoxy resin nanofiber capsules, super-hydrophobic modified nano-alumina and wet strength agent are sequentially added to the pure fiber slurry to obtain a mixed insulation paper slurry; The mixed insulation paper slurry is subjected to post-treatment and hot-pressing treatment to obtain a self-repairing super-hydrophobic modified insulation paper.

[0007] Further, the specific steps for preparing the epoxy resin nanofiber capsules are as follows: A mixed solution of epoxy resin and latent curing agent is used as the core layer material, and a N,N-dimethylformamide solution of polyacrylonitrile is used as the shell layer material, and a coaxial electrospinning method is used to prepare a core-shell structure nanofiber membrane with an epoxy resin system as the core and polyacrylonitrile as the shell by adjusting the spinning parameters; then the collected nanofiber membrane is subjected to a short cutting treatment to obtain an epoxy resin nanofiber capsule with a length of 50-500 μm.

[0008] Further, the concentration of the N,N-dimethylformamide solution of polyacrylonitrile is 10wt%-15wt%; The spinning parameters are as follows: the spinning voltage is 12-20 kV, the receiving distance is 10-20 cm, the solution flow rate of the core layer material is 0.5-1.2 mL / h, the solution flow rate of the shell layer material is 0.8-1.8 mL / h, the spinning temperature is 15-30℃, and the relative humidity is 30%-50%.

[0009] Further, the specific steps for preparing the super-hydrophobic modified nano-alumina are as follows: The nano-alumina is dispersed in anhydrous ethanol, and then a surface modifier is added for a reflux reaction, and after the reaction is completed, centrifugation, washing and drying are performed to obtain the super-hydrophobic modified nano-alumina; The surface modifier is heptadecafluorodecyltrimethoxysilane, octyltriethoxysilane or KH-550 silane coupling agent.

[0010] Further, the ratio of the nano-alumina, anhydrous ethanol and surface modifier is 1:0.1-1:0.3, and the mass ratio of the nano-alumina and anhydrous ethanol is 1:(12-20); The reflux reaction is performed at a temperature of 70-80℃ for 6-8 h; The particle size of the nano-alumina is 20-100 nm.

[0011] Further, the pure fiber pulp is obtained by defibrating unbleached coniferous wood pulp board in water; The mass concentration of the pure fiber pulp is 0.5%-1.0%.

[0012] Further, the addition amount of the epoxy resin nanofiber capsule is 10%-40% of the mass of the absolute dry fibers in the pure fiber pulp; The addition amount of the super-hydrophobic modified nano-alumina is 5%-20% of the mass of the absolute dry fibers; The addition amount of the wet strength agent is 0.5%-2.0% of the mass of the absolute dry fibers; The wet strength agent is a polyamide epoxy chloropropane.

[0013] Further, the post-processing is to shape the mixed insulation paper pulp through a paper machine, and after dewatering through pressing, wet paper sheets are obtained; the wet paper sheets are pre-dried and then subjected to hot pressing treatment to obtain self-repairing super-hydrophobic modified insulation paper.

[0014] Further, the pre-drying temperature is 105-120 DEG C, and the time is 10-30 min. The hot pressing treatment temperature is 120-160 DEG C, the pressure is 5-15 MPa, and the time is 10-30 min.

[0015] The application further discloses a self-repairing super-hydrophobic modified insulation paper prepared by the preparation method.

[0016] Compared with the prior art, the application has the following beneficial effects: The application discloses a preparation method of self-repairing super-hydrophobic modified insulation paper.

[0017] The application further discloses the self-repairing super-hydrophobic modified insulation paper prepared by the preparation method. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 FIG. 1 is a preparation process diagram of self-repairing super-hydrophobic modified insulation paper. DETAILED DESCRIPTION

[0019] To enable those skilled in the art to have a better understanding of the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used herein have their usual meanings to those skilled in the art of the present application, and in case of conflict, the definition in the specification shall prevail.

[0020] Theories or mechanisms described and disclosed herein, whether correct or not, should not be considered limiting the scope of the present application, i.e., the present application can be practiced without regard to any particular theory or mechanism.

[0021] Herein, all features defined in the form of numerical ranges or percentage ranges such as numerical values, amounts, contents and concentrations are for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have encompassed and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0022] Herein, unless otherwise specified, "comprise", "include", "contain", "have", or similar words encompass the meaning of "consist of" and "consist essentially of", for example, "A comprises a" encompasses the meaning of "A comprises a and other" and "A comprises only a".

[0023] Herein, for the sake of brevity, all possible combinations of the various technical features in the various embodiments or examples are not described. Therefore, as long as there is no contradiction in the combination of the technical features, the technical features in the various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered as the scope disclosed in the specification.

[0024] The present application provides a preparation method of high-thermal-conductivity, self-repairing, super-hydrophobic insulation paper. The method first prepares epoxy resin nanofiber capsules by coaxial electrospinning; super-hydrophobic modification is performed on nano-aluminum oxide by fluorination / long-chain alkyl silane; then plant fibers, super-hydrophobic modified nano-aluminum oxide, nanofiber capsules and wet strength agent are mixed and papermaking; finally, hot pressing is performed. Hot pressing causes the capsules to break, and the epoxy resin solidifies to form a high-thermal-conductivity network and endow the material with self-repairing potential; the uniformly distributed super-hydrophobic modified nano-aluminum oxide builds a stable super-hydrophobic barrier, greatly reducing the moisture absorption of the material. The insulation paper prepared by the present application integrates high-thermal-conductivity, self-repairing and super-hydrophobic moisture-proof functions, and can comprehensively improve the long-term operation reliability of power equipment under complex working conditions.

[0025] As shown in the following scheme: Figure 1 The method mainly comprises the following steps: Step 1: Preparation of epoxy resin nanofiber capsules A mixed solution of epoxy resin (such as E-51) and latent curing agent (such as dicyandiamide) is used as the core layer material, and a polyacrylonitrile (PAN) N,N-dimethylformamide (DMF) solution is used as the shell layer material by using coaxial electrospinning technology. By adjusting the spinning parameters, a core-shell structure nanofiber with an epoxy resin system as the core and PAN as the shell is prepared. Subsequently, the collected nanofiber membrane is subjected to a short-cut treatment to obtain short-cut epoxy resin nanofiber capsules with a length of 50-500 μm; Step 2: Preparation of super-hydrophobic modified nano-alumina The surface of nano-alumina (particle size 20-100 nm) is modified by using long-chain alkyl or fluorinated silane coupling agents. The nano-alumina is dispersed in anhydrous ethanol, and a metered amount of heptadecafluorodecyltrimethoxysilane (FAS) or octyltriethoxysilane is added, and the mixture is refluxed at 70-80°C for 6-8 hours. After the reaction is completed, the mixture is centrifuged, washed, and dried to obtain super-hydrophobic modified nano-alumina with a low-surface-energy fluorocarbon chain or long alkyl chain grafted on the surface. Step 3: Preparation of mixed insulation paper pulp Unbleached coniferous wood pulp sheets are defibrated in water to obtain a pure fiber pulp with a mass concentration of 0.5%-1.0%. Under high-speed stirring, a certain amount of super-hydrophobic modified nano-alumina is added to the pure fiber pulp, followed by adding a certain amount of epoxy resin nanofiber capsules. The super-hydrophobic modified nano-alumina is added in an amount of 10%-40% of the mass of the absolutely dry fibers, the epoxy resin nanofiber capsules are added in an amount of 5%-20% of the mass of the absolutely dry fibers, and a suitable amount of polyamide epoxy chloropropane (PAE) wet strength agent is added in an amount of 0.5%-2.0% of the mass of the absolutely dry fibers.

[0026] The mixture is continuously stirred to make it uniform, and a stable mixed insulation paper pulp is formed. The mixture is continuously stirred to make it uniform, and a stable mixed insulation paper pulp is formed. Step 4: Insulation paper making and hot-pressing curing The mixed pulp is formed into a sheet by a paper former, and after being pressed and dewatered, a wet paper sheet is obtained. The wet paper sheet is pre-dried at 105°C for 10 minutes. Subsequently, the dried paper sheet is placed in a hot press, and is subjected to hot-pressing treatment at a temperature of 120-160°C and a pressure of 5-15 MPa for 10-30 minutes. In this process, the PAN shell of the epoxy resin nanofiber capsule softens, the internal epoxy resin and curing agent flow out, infiltrate the fibers, and undergo cross-linking and curing under the action of pressure and temperature, and at the same time, the super-hydrophobic nano-alumina and the plant fibers are firmly bonded together, and finally a dense "high-thermal-conductivity-self-repairing-super-hydrophobic" three-dimensional network structure is formed, i.e., the high-performance insulation paper is obtained.

[0027] The application will be further described in connection with the following detailed description and examples. It should be understood that these examples are intended to illustrate the application and are not intended to limit the scope of the application. Moreover, it should be understood that modifications can be made by those skilled in the art with the benefit of the information presented in this disclosure, and yet still be within the scope of the application as described by the claims attached hereto.

[0028] The following examples were conducted using conventional equipment in the art. Unless otherwise indicated, the experimental procedures in the following examples were conducted under conventional conditions, or under conditions recommended by the manufacturer. The following examples were conducted using various materials, unless otherwise indicated, and conventional commercially available products were used, at conventional specifications in the art. In the specification of the application and in the following examples, unless otherwise specified, "%" means weight percent, "parts" means parts by weight, and ratios are by weight.

[0029] Example 1 Example 1 Step 1: Preparation of epoxy nanofiber capsules An epoxy E-51 solution with a concentration of 25 wt% and dicyandiamide (mass ratio 10:1) in acetone was prepared as the core solution; a PAN (Mw=150,000) solution with a concentration of 10 wt% in DMF was prepared as the shell solution. Coaxial electrospinning was used, with a spinning voltage of 18 kV, a receiving distance of 18 cm, a core flow rate of 1.0 mL / h, a shell flow rate of 1.5 mL / h, an ambient temperature of 25±2°C, and a humidity of 40±5%. A core-shell nanofiber membrane was prepared, which was then cut to an average length of about 300 μm to obtain epoxy nanofiber capsules; Step 2: 10.0 g of nano-alumina with an average particle size of 100 nm was weighed out and dispersed in 200 mL of anhydrous ethanol, and ultrasonically treated for 30 minutes; then 1.0 g of γ-aminopropyl triethoxysilane (KH-550, amino silane) was added, and the mixture was refluxed at 78°C for 7 hours; after the reaction was completed, the mixture was centrifuged, washed with anhydrous ethanol three times, and dried at 80°C under vacuum for 12 hours to obtain modified nano-alumina with a surface grafted with amino groups; Step 3: Preparation of mixed slurry and insulation paper Take 10.0 g of unbleached needle leaf wood pulp fibers with absolute dry mass, and defibrate in 2.0 L of deionized water in a standard defibrator to obtain a pure fiber slurry with a mass concentration of about 0.5%; under high-speed stirring (600 rpm), add to the slurry in sequence: 2.0 g (20% of the absolute dry fiber mass) of the modified nano-alumina obtained in step 2, 2.0 g (20% of the absolute dry fiber mass) of the epoxy resin nano-fiber capsules obtained in step 1 (capsule to alumina mass ratio 1:1), and 0.15 g (1.5% of the absolute dry fiber mass) of polyamide epoxy chloropropane (PAE) wet strength agent; continue stirring for 60 minutes to form a uniform mixed slurry; Step 4: Papermaking and hot-pressing curing Pour the mixed slurry into a standard sheet former to form a shape, and obtain a wet paper sheet by pressing and dewatering; place the wet paper sheet in an oven at 105°C for 15 minutes for pre-drying; then place the dried paper sheet in a flat press, and hot-press at a temperature of 130°C and a pressure of 8 MPa for 25 minutes; after natural cooling, obtain the reinforced interface-modified insulation paper.

[0030] This example aims to demonstrate the performance improvement brought by amino silane in improving the interface bonding between nano-alumina and plant fiber / resin matrix, which is hydrophobic due to the organic long chain, but does not reach the super-hydrophobic level.

[0031] Example 2 Step 1: Preparation of epoxy resin nano-fiber capsules Prepare an acetone solution of epoxy resin E-51 and dicyandiamide (mass ratio 10:1) with a concentration of 25wt% as the core layer liquid; prepare a DMF solution of PAN (Mw=150,000) with a concentration of 10wt% as the shell layer liquid. Use coaxial electrospinning, set the spinning voltage to 18 kV, the receiving distance to 18 cm, the core layer flow rate to 1.0 mL / h, the shell layer flow rate to 1.5 mL / h, the ambient temperature to 25±2°C, and the humidity to 40±5%. Prepare a core-shell nano-fiber membrane, and then cut it to an average length of about 300μm to obtain the epoxy resin nano-fiber capsules; Step 2: Preparation of super-hydrophobic modified nano-alumina Take 10.0 g of nano-alumina with an average particle size of 50 nm, disperse in 200 mL of absolute ethanol, and ultrasonic treat for 30 minutes. Add 2.0 g of heptadecafluorodecyltrimethoxysilane (FAS), and reflux at 75°C for 7 hours. After the reaction is completed, centrifugal separate, wash with absolute ethanol three times, and vacuum dry at 80°C for 12 hours to obtain super-hydrophobic modified nano-alumina (the modified powder can float on the water surface for a long time); Step 3: Preparation of mixed slurry and insulation paper Take 10.0 g of unbleached needle leaf wood pulp fibers with absolute dry mass, and defibrate in 1.5 L of deionized water to obtain a pure fiber slurry with a mass concentration of about 0.67%. Under high-speed stirring (600 rpm), add the following to the slurry in sequence: 3.0 g (30% of the absolute dry fiber mass) of the super-hydrophobic modified nano-aluminum oxide obtained in step 2, 1.5 g (15% of the absolute dry fiber mass) of the epoxy resin nano-fiber capsules obtained in step 1 (capsule to aluminum oxide mass ratio 1:2), and 0.15 g (1.5% of the absolute dry fiber mass) of PAE wet strength agent. Continue stirring for 60 minutes to form a uniform mixed slurry; Step 4: Papermaking and hot-pressing curing The papermaking process is the same as that of step 4 of Example 1; the hot-pressing process parameters are adjusted to: temperature 140°C, pressure 10 MPa, time 20 minutes; after cooling, a self-repairing super-hydrophobic modified insulation paper is obtained.

[0032] This example demonstrates the realization of super-hydrophobic modification using fluorinated silane (FAS), combined with nano-fiber capsules, to prepare an insulation paper that integrates high thermal conductivity, self-repairing, and super-hydrophobic moisture-proof functions.

[0033] Example 3 Step 1: Preparation of epoxy resin nano-fiber capsules Prepare an acetone solution of epoxy resin E-51 and dicyandiamide (mass ratio 10:1) with a concentration of 28wt% as the core layer liquid; prepare a DMF solution of PAN (Mw=150,000) with a concentration of 12wt% as the shell layer liquid. Set the spinning voltage to 15 kV, the receiving distance to 15 cm, the core layer flow rate to 0.8 mL / h, the shell layer flow rate to 1.2 mL / h, and the environmental conditions to be the same as in Example 1. Prepare and cut the nano-fiber membrane to obtain short capsules with an average length of about 100 μm; Step 2: Preparation of super-hydrophobic modified nano-aluminum oxide Take 10.0 g of nano-aluminum oxide with an average particle size of 20 nm, disperse in 200 mL of absolute ethanol, and ultrasonic treat for 30 minutes; add 1.5 g of octyl triethoxysilane, and reflux at 78°C for 6.5 hours; the subsequent centrifugation, washing, and drying steps are the same as in Example 2 to obtain super-hydrophobic nano-aluminum oxide modified with alkyl silane; Step 3: Mixed slurry preparation and insulation paper preparation Take 10.0 g of unbleached needle leaf wood pulp fibers with absolute dry mass, and defibrate in 1.0 L of deionized water to obtain a pure fiber slurry with a mass concentration of about 1.0%. Under high-speed stirring (800 rpm), add to the slurry in sequence: 0.5 g (5% of the absolute dry mass of the fibers) of the super-hydrophobic modified nano-aluminum oxide obtained in step 2, 4.0 g (40% of the absolute dry mass of the fibers) of the epoxy resin nano-fiber capsules (capsule to aluminum oxide mass ratio 8:1) obtained in step 1, and 0.1 g (1.0% of the absolute dry mass of the fibers) of PAE wet strength agent; continue stirring for 60 minutes to form a uniform mixed slurry; Step 4: papermaking and hot-pressing curing The papermaking process is the same as that in step 4 of Example 1; the wet paper sheet is pre-dried at 110°C for 25 minutes; the hot-pressing process parameters are: temperature 160°C, pressure 12 MPa, and time 15 minutes; after cooling, a self-repairing super-hydrophobic modified insulation paper is obtained.

[0034] This example verifies that under the conditions of smaller particle size of aluminum oxide and higher capsule addition amount, a high-performance super-hydrophobic insulation paper can also be prepared using long-chain alkyl silane (octyl triethoxysilane), which embodies the universality of the technical solution of the present application.

[0035] Comparative Example 1 Without adding any filler, only 1.5% of PAE wet strength agent is added to the pure fiber slurry, and a conventional insulation paper is prepared according to the same papermaking and drying (without hot-pressing) process.

[0036] Table 1 is a comparison of the performance data of the insulation papers prepared in the comparative examples and examples, from which it can be seen that the insulation papers prepared in Examples 1, 2 and 3 of the present application are far superior to the comparative example in terms of thermal conductivity and self-repairing ability. In particular, Example 2 using super-hydrophobic modification achieves super-hydrophobic characteristics (contact angle > 150°), and its 24-hour moisture absorption rate is greatly reduced to below 1.5%, with the best overall performance.

[0037] Table 1 is a comparison of the performance data of the insulation papers prepared in the comparative examples and examples, from which it can be seen that the insulation papers prepared in Examples 1, 2 and 3 of the present application are far superior to the comparative example in terms of thermal conductivity and self-repairing ability. In particular, Example 2 using super-hydrophobic modification achieves super-hydrophobic characteristics (contact angle > 150°), and its 24-hour moisture absorption rate is greatly reduced to below 1.5%, with the best overall performance.

[0038] The above content only illustrates the technical idea of the present application and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical solution falls within the protection scope of the claims of the present application.

Claims

1. A method for preparing a self-healing superhydrophobic modified insulating paper, characterized in that, Includes the following steps: Preparation of epoxy resin nanofiber capsules and superhydrophobic modified nano-alumina; While stirring, epoxy resin nanofiber capsules, superhydrophobic modified nano-alumina, and wet strength agent are added sequentially to pure fiber pulp to obtain mixed insulating pulp. The mixed insulating pulp is post-treated and hot-pressed to obtain self-healing superhydrophobic modified insulating paper.

2. The method for preparing a self-healing superhydrophobic modified insulating paper according to claim 1, characterized in that, The specific steps for preparing epoxy resin nanofiber capsules are as follows: Using a mixed solution of epoxy resin and latent curing agent as the core material and an N,N-dimethylformamide solution of polyacrylonitrile as the shell material, a core-shell structured nanofiber membrane with epoxy resin as the core and polyacrylonitrile as the shell was prepared by coaxial electrospinning and by adjusting the spinning parameters. Subsequently, the collected nanofiber membranes were chopped to obtain epoxy resin nanofiber capsules with a length of 50~500μm.

3. The method for preparing a self-healing superhydrophobic modified insulating paper according to claim 2, characterized in that, The concentration of the N,N-dimethylformamide solution of the polyacrylonitrile is 10wt%~15wt%; The spinning parameters are as follows: spinning voltage is 12~20kV, receiving distance is 10~20cm, solution flow rate of core material is 0.5~1.2mL / h, solution flow rate of shell material is 0.8~1.8mL / h, spinning temperature is 15~30℃, and relative humidity is 30%~50%.

4. The method for preparing a self-healing superhydrophobic modified insulating paper according to claim 1, characterized in that, The specific steps for preparing superhydrophobic modified nano-alumina are as follows: Nano-alumina was dispersed in anhydrous ethanol, and then a surface modifier was added for reflux reaction. After the reaction was completed, the nano-alumina was centrifuged, washed and dried to obtain superhydrophobic modified nano-alumina. The surface modifier is heptadecafluorodecyltrimethoxysilane, octyltriethoxysilane, or KH-550 silane coupling agent.

5. The method for preparing a self-healing superhydrophobic modified insulating paper according to claim 4, characterized in that, The ratio of the amount of nano-alumina, anhydrous ethanol and surface modifier is 1:0.1 to 1:0.3; the mass ratio of nano-alumina and anhydrous ethanol is 1:(12 to 20). The reflux reaction is carried out at a temperature of 70-80°C for 6-8 hours. The particle size of the nano-alumina is 20~100nm.

6. The method for preparing a self-healing superhydrophobic modified insulating paper according to claim 1, characterized in that, The pure fiber pulp is obtained by dissolving unbleached softwood pulp board in water; The mass concentration of the pure fiber pulp is 0.5%~1.0%.

7. The method for preparing a self-healing superhydrophobic modified insulating paper according to claim 1, characterized in that, The amount of epoxy resin nanofiber capsules added is 10% to 40% of the oven-dry fiber mass in the pure fiber slurry; The amount of superhydrophobic modified nano-alumina added is 5% to 20% of the dry fiber mass; The wet strength agent is added at a rate of 0.5% to 2.0% of the oven-dry fiber mass. The wet strength agent is polyamide epichlorohydrin.

8. The method for preparing a self-healing superhydrophobic modified insulating paper according to claim 1, characterized in that, The post-processing involves forming the mixed insulating pulp using a paper machine, dewatering it by pressing to obtain a wet paper sheet, pre-drying the wet paper sheet, and then hot-pressing it to obtain a self-healing superhydrophobic modified insulating paper.

9. The method for preparing a self-healing superhydrophobic modified insulating paper according to claim 8, characterized in that, The pre-drying temperature is 105~120℃, and the time is 10~30min; The hot pressing treatment is performed at a temperature of 120~160℃, a pressure of 5~15MPa, and a time of 10~30min.

10. A self-healing superhydrophobic modified insulating paper, characterized in that, The self-healing superhydrophobic modified insulating paper is prepared by any one of the preparation methods described in claims 1 to 9; the thermal conductivity is greater than 0.8 W / (m·K), the electrical insulation strength is greater than 50 kV / mm, the contact angle with water is greater than 150°, and the moisture absorption rate is less than 2.0% after 24 hours.

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