Insulator surface low-dielectric coating material and preparation method and application thereof

Abstract

The invention discloses an insulator surface low-dielectric coating material and a preparation method and application thereof.The preparation method includes the steps that at the room temperature, epoxy resin, a curing agent and a catalyst are mixed to obtain an epoxy mixture, and the epoxy mixture is mixed with hollow glass beads or polytetrafluoroethylene powder to obtain a mixture; performing ultrasonic stirring and vacuum defoaming on the obtained mixture in a high-temperature vacuum environment to obtain a coating mixed solution; and spraying the coating mixed solution on the surface of the insulator to be coated through a high-pressure spray gun, and carrying out high-temperature curing to obtain the low-dielectric coating of the insulator. The preparation process is simple, the preparation cost is not high, the prepared coating has a low dielectric constant, the electrical property of the insulator can be improved, meanwhile, the mechanical property of the coating is excellent, and the application requirement can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of insulator materials, and in particular relates to a low-dielectric coating material on the surface of an insulator, a preparation method thereof, and an application thereof. Background Art

[0002] Insulators are key components in power transmission systems, providing mechanical support and electrical insulation. They are widely used for insulation and mechanical fixing of high-voltage overhead transmission lines, power plants, and substation busbars. Their performance directly impacts the reliability of national power transmission. As my country's power system evolves toward ultra-high voltage, large-capacity, and long-distance transmission, the high dielectric constant of traditional ceramic insulators and the uneven electric field distribution on their surfaces can lead to problems such as partial discharge and flashover, compromising the reliable and stable operation of the power system.

[0003] In order to improve the insulating performance of insulators and improve the dielectric constant distribution of insulators, the electric field distortion can be suppressed and the electric field distribution can be improved by regulating the dielectric constant distribution of insulators, which has achieved relatively significant results.

[0004] Currently, researchers are using a variety of methods to control the dielectric constant distribution on the surface of insulators. Common methods include fluorination modification, magnetron sputtering, and surface coating. A common surface coating method is to mix a low-dielectric constant material with a matrix material such as epoxy resin to prepare a low-dielectric composite material, which is then coated on the surface of the insulator. Coatings with a dielectric constant gradient distribution can also be constructed by setting a gradient distribution of coating thickness. By controlling the dielectric constant of the coating, charge accumulation on the insulator surface can be suppressed, electric field distortion can be reduced, the electric field distribution on the insulator surface can be improved, and the insulator's electrical resistance can be enhanced.

[0005] Existing insulator coating preparation methods suffer from several issues, making their future prospects for engineering application uncertain. First, the preparation process is cumbersome and complex, often requiring modification of the epoxy resin and its curing agent, often requiring multiple steps. Second, the cost is high, as some of the raw materials used in existing coatings are not commonly used in industrial applications and are relatively expensive. Third, the coatings exhibit poor performance, with issues such as uneven surface morphology and loose adhesion to the insulator. These issues hinder the further application of insulator coatings in engineering. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and provide a low-dielectric coating material for the surface of an insulator, a preparation method thereof, and an application thereof, so as to solve the technical problems of the existing insulator coating preparation process being complex, high cost, and poor coating adhesion. By optimizing the material composition and coating process, a uniform electric field distribution and charge suppression effect can be achieved.

[0007] The present invention adopts the following technical solutions: A method for preparing a low-dielectric coating material on an insulator surface comprises the following steps: At room temperature, an epoxy resin, a curing agent and a catalyst are mixed to obtain an epoxy mixture, and the epoxy mixture is mixed with hollow glass microspheres or polytetrafluoroethylene powder to obtain a mixture; Under a high-temperature vacuum environment, the obtained mixture is subjected to ultrasonic stirring and vacuum degassing to obtain a coating mixed solution; The coating mixture solution is sprayed onto the surface of the insulator to be coated through a high-pressure spray gun, and a low-dielectric coating for the insulator is obtained after high-temperature curing.

[0008] Preferably, by weight, the epoxy resin is 90-100 parts, the curing agent is 86-90 parts, and the catalyst is 1-2 parts; wherein the epoxy resin is bisphenol A diglycidyl ether type, bisphenol F diglycidyl ether type or hydrogenated bisphenol A diglycidyl ether type epoxy; The curing agent is an amine curing agent, an acid anhydride curing agent or an active ester curing agent; The catalyst is 2,4,6-tris(dimethylaminomethyl)phenol, 2-ethyl-4-methylimidazole and 2-phenylimidazole.

[0009] Preferably, the hollow glass microspheres are 20 to 30 parts by weight, and the polytetrafluoroethylene powder is 40 to 60 parts by weight.

[0010] Preferably, the hollow glass microspheres have a particle size of 15-135 μm and a density of 0.125-0.60 g / cm 3 .

[0011] Furthermore, the present invention is characterized in that the particle size of the hollow glass microspheres is 30-120 μm and the density is 0.20 g / cm 3 .

[0012] Preferably, the particle size of polytetrafluoroethylene powder is 1-50 μm and the density is 2.0-3.0 g / cm 3 .

[0013] Furthermore, the present invention is characterized in that the particle size of the polytetrafluoroethylene powder is 10-20 μm and the density is 2.3 g / cm 3 .

[0014] Preferably, the stirring temperature of the ultrasonic stirring is 80-150° C., the stirring rate is 400-800 r / min, and the stirring time is 10-15 min.

[0015] Another technical solution of the present invention is to apply a low dielectric coating material on the surface of the insulator.

[0016] The third technical solution of the present invention is the application of the low-dielectric coating material on the surface of the insulator in electronic devices and insulation systems.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: A method for preparing a low-dielectric coating material for the surface of an insulator uses epoxy resin as a matrix material, combined with hollow glass microspheres or polytetrafluoroethylene powder, to significantly reduce the dielectric constant of the coating. Ultrasonic stirring and degassing processes in a high-temperature vacuum environment can eliminate micropores inside the coating, improve the density and uniformity of the coating, and reduce the risk of electric field distortion. High-pressure spraying technology ensures that the coating is tightly bonded to the insulator surface, enhancing adhesion. Through material component optimization, process parameter control, and interface bonding enhancement, the dielectric properties, mechanical stability, and engineering applicability of the coating are comprehensively improved, making it particularly suitable for protecting power equipment in complex environments.

[0018] Furthermore, bisphenol A / F type epoxy resin has high cross-linking density and weather resistance, which can improve the mechanical strength and heat resistance of the coating, and has good compatibility with epoxy resin; the composite filling of hollow glass microspheres achieves synergistic optimization of lightweight and low dielectric, while improving the impact resistance of the coating.

[0019] Furthermore, the refined control of the particle size of the hollow glass microspheres improves their dispersibility in the epoxy matrix and reduces the porosity, thereby improving the hydrophobicity and stain resistance of the coating surface.

[0020] Furthermore, high-temperature ultrasonic stirring promotes uniform dispersion of fillers, reduces agglomeration, shortens degassing time, and improves production efficiency.

[0021] Furthermore, the final coating has low dielectric properties, high weather resistance and strong adhesion, making it suitable for the electric field equalization and anti-pollution flashover requirements of ultra-high voltage transmission lines.

[0022] In summary, the preparation process of the present invention is simple, the preparation cost is low, the prepared coating has a low dielectric constant, which can improve the electrical properties of the insulator, and the mechanical properties of the coating are excellent, which can meet application requirements.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings to be used in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1The dielectric constant diagram of coating 1 prepared in Example 1 of the present invention; Figure 2 The dielectric constant diagram of coating 2 prepared in Example 2 of the present invention; Figure 3 The dielectric constant diagram of coating 3 prepared in Example 3 of the present invention; Figure 4 This is a diagram of the dielectric constant of coating 4 prepared in comparative example 1 of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] In the present invention, unless otherwise specified, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution.

[0028] In the present invention, unless otherwise specified, all technical features and preferred features mentioned herein can be combined with each other to form a new technical solution.

[0029] In the present invention, unless otherwise specified, percentages (%) or parts refer to percentages by weight or parts by weight relative to the composition.

[0030] In the present invention, unless otherwise specified, the components involved or their preferred components can be combined with each other to form a new technical solution.

[0031] In this disclosure, unless otherwise specified, the numerical range "a-b" is an abbreviation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6-22" indicates that all real numbers between "6-22" are listed herein, and "6-22" is merely an abbreviation for these numerical combinations.

[0032] The "range" disclosed in the present invention is in the form of lower limit and upper limit, which can be one or more lower limits, and one or more upper limits respectively.

[0033] In the present invention, the term "and / or" used herein refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0034] In the present invention, unless otherwise specified, each reaction or operation step can be carried out sequentially or in accordance with the order. Preferably, the reaction method herein is carried out sequentially.

[0035] Unless otherwise indicated, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content can also be applied to the present invention.

[0036] The present invention provides a low-dielectric coating material for an insulator surface, a preparation method thereof, and an application thereof.

[0037] The present invention provides a method for preparing a low-dielectric coating material on an insulator surface, comprising the following steps: S1. At room temperature, weigh the epoxy resin, curing agent, catalyst, hollow glass microspheres, and polytetrafluoroethylene powder in proportion and mix them to obtain a mixture; S2, ultrasonically stirring and vacuum degassing the mixture under a high temperature vacuum environment to obtain a coating mixed solution; When the coating mixture is stirred and degassed to obtain a mixed solution, the stirring temperature is 80-150° C., the stirring rate is 400-800 r / min, and the stirring time is 10-15 min.

[0038] S3. Spray the coating mixture solution onto the surface of the insulator to be coated by a high-pressure spray gun to obtain a low-dielectric coating for the insulator, and then cure it at high temperature to obtain a low-dielectric coating for the insulator.

[0039] When the coating mixed solution is sprayed onto the insulator surface, the mixed solution is loaded into a cavity with a high-speed rotating blade to dilute the high-viscosity solution and then sprayed onto the insulator surface through a high-pressure spray gun.

[0040] A low-dielectric coating material for the surface of an insulator is prepared by the above method and comprises, by weight, 90-100 parts of epoxy resin, 86-90 parts of curing agent, 1-2 parts of catalyst, 20-30 parts of hollow glass microspheres and 40-60 parts of polytetrafluoroethylene powder.

[0041] The epoxy resin is selected from bisphenol A diglycidyl ether type, bisphenol F diglycidyl ether type or hydrogenated bisphenol A diglycidyl ether type epoxy; Preferably, the epoxy resin is E51, E44 or a similar epoxy resin with an epoxy value between 0.44 and 0.53.

[0042] E51 epoxy resin is a bisphenol A epoxy resin with a high epoxy value, generally reaching 0.51~0.54eq / 100g, which means it has high reactivity and is often used as a composite material matrix. E51 epoxy resin has excellent electrical insulation properties, with its dielectric loss at 50Hz as low as 0.0078. In addition, E51 has a low viscosity, which facilitates impregnation, pouring and spraying.

[0043] The curing agent is selected from an amine curing agent, an acid anhydride curing agent or an active ester curing agent; preferably, the amine curing agent is ethylenediamine or diethylenetriamine; the acid anhydride curing agent is phthalic anhydride or methylhexahydrophthalic anhydride; and the active ester curing agent is bisphenol A type active ester or bis(2-methoxy-4-(oxy-2-methyl)phenyl)isophthalate.

[0044] The catalyst is selected from 2,4,6-tris(dimethylaminomethyl)phenol, 2-ethyl-4-methylimidazole, 2-phenylimidazole and the like; preferably, the catalyst is 2,4,6-tris(dimethylaminomethyl)phenol.

[0045] The particle size of hollow glass microspheres is 15~135μm and the density is 0.125~0.60g / cm 3 The particle size of polytetrafluoroethylene powder is 1~50μm and the density is 2.0~3.0g / cm 3 ; Preferably, the hollow glass microspheres have a particle size of 30-120 μm and a density of 0.20 g / cm 3 The particle size of polytetrafluoroethylene powder is 10~20μm and the density is 2.3g / cm 3 .

[0046] Hollow glass microspheres are spherical particles made primarily of silicate materials, exhibiting excellent resistance to acids, alkali solvents, and oxidation. Their hollow structure results in a dielectric constant close to that of air, ranging from 1.5 to 2.5, making them suitable for the preparation of low-dielectric composite materials. Polytetrafluoroethylene (PTFE) has good compatibility and a low molecular weight, making it widely used in the processing of modified engineering plastics, modified resins, and highly corrosion-resistant coatings, improving coating viscosity and lubricity, reducing the coefficient of friction, and enhancing wear and corrosion resistance.

[0047] The present invention describes a low-dielectric coating material for gold insulator surfaces that can be used in electronic devices and insulation systems. By mixing epoxy resin with hollow glass microspheres (low-dielectric constant) and polytetrafluoroethylene (PTFE), the method effectively reduces the dielectric constant and dielectric loss of the epoxy matrix, thereby suppressing electric field distortion on the insulator surface, reducing the risk of partial discharge, and improving the insulation reliability of the insulator in high-voltage environments. Furthermore, the hollow structure of the hollow glass microspheres effectively absorbs stress, improving the coating's fracture toughness. The chemical inertness of PTFE imparts excellent corrosion resistance and hydrophobicity to the insulator coating, effectively reducing the risk of contamination flashover.

[0048] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0049] Example 1 This embodiment relates to the preparation of a low dielectric coating for an insulator, specifically as follows: S1: At room temperature, 9.0 g of E51 epoxy resin, 8.6 g of methylhexahydrophthalic anhydride curing agent, and 0.1 g of 2,4,6-tris(dimethylaminomethyl)phenol were mixed to obtain epoxy mixture A; S2: At room temperature, the obtained epoxy mixture A was mixed with 2.0 g of hollow glass microspheres and 4.0 g of polytetrafluoroethylene powder to obtain a mixture B, wherein the ratio of the epoxy resin, the anhydride curing agent, the catalyst, the hollow glass microspheres, and the polytetrafluoroethylene in the mixture B was 90:86:1:20:40; Preferably, the hollow glass microspheres have a particle size of 30-50 μm and a density of 0.20 g / cm 3 .

[0050] S3: Mixture B was mechanically stirred uniformly in a planetary mixer at 100° C., with a stirring speed of 400 r / min and a stirring time of 120 s in the first stage; a stirring speed of 600 r / min and a stirring time of 180 s in the second stage; a stirring speed of 800 r / min and a stirring time of 300 s in the third stage; a stirring speed of 700 r / min and a stirring time of 120 s in the fourth stage; and a stirring speed of 600 r / min and a stirring time of 60 s in the fifth stage. After the stirring was completed, vacuum degassing was performed to obtain a mixed solution C; S4: The mixed solution C is loaded into a cavity with a high-speed rotating blade, and the principle of fluid shear thinning is used to thin the solution with high viscosity, and then sprayed onto the surface of the insulator through a high-pressure spray gun; S5: subjecting the insulator to high-temperature curing treatment, wherein the first curing temperature is 80° C. and the curing time is 2 h; the second curing temperature is 120° C. and the curing time is 4 h; and the third curing temperature is 150° C. and the curing time is 4 h, thereby obtaining the insulator low dielectric coating 1.

[0051] The dielectric constant and dielectric loss tangent of coating 1 are as follows: Figure 1 shown.

[0052] Example 2 This embodiment relates to the preparation of a low dielectric coating for an insulator, specifically as follows: S1: At room temperature, 10.0 g of E44 epoxy resin, 9.5 g of methylhexahydrophthalic anhydride curing agent, and 0.2 g of 2,4,6-tris(dimethylaminomethyl)phenol were mixed to obtain epoxy mixture A; S2: At room temperature, the obtained epoxy mixture A was mixed with 3.0 g of hollow glass microspheres and 6.0 g of polytetrafluoroethylene powder to obtain a mixture B, wherein the ratio of epoxy resin, anhydride curing agent, catalyst, hollow glass microspheres and polytetrafluoroethylene in the mixture B was 100:95:2:30:60; Preferably, the hollow glass microspheres have a particle size of 50-80 μm and a density of 0.20 g / cm 3 The particle size of polytetrafluoroethylene powder is 10~20μm and the density is 2.3g / cm 3 .

[0053] S3: Mixture B was mechanically stirred uniformly in a planetary mixer at 100° C., with a stirring speed of 600 r / min and a stirring time of 120 s in the first stage; a stirring speed of 800 r / min and a stirring time of 180 s in the second stage; a stirring speed of 1000 r / min and a stirring time of 300 s in the third stage; a stirring speed of 800 r / min and a stirring time of 120 s in the fourth stage; and a stirring speed of 600 r / min and a stirring time of 60 s in the fifth stage. After the stirring was completed, vacuum degassing was performed to obtain a mixed solution C; S4: The mixed solution C is loaded into a cavity with a high-speed rotating blade, and the principle of fluid shear thinning is used to thin the solution with high viscosity, and then sprayed onto the surface of the insulator through a high-pressure spray gun; S5: subjecting the insulator to high-temperature curing treatment, wherein the first curing temperature is 80°C and the curing time is 2 hours; the second curing temperature is 120°C and the curing time is 4 hours; and the third curing temperature is 150°C and the curing time is 4 hours, thereby obtaining the insulator low dielectric coating 2.

[0054] The dielectric constant and dielectric loss tangent of coating 2 are as follows: Figure 2 shown.

[0055] Example 3 This embodiment relates to the preparation of a low dielectric coating for an insulator, specifically as follows: S1: At room temperature, 9.5 g of hydrogenated bisphenol A epoxy resin, 8.8 g of methylhexahydrophthalic anhydride curing agent, and 0.1 g of 2,4,6-tris(dimethylaminomethyl)phenol were mixed to obtain epoxy mixture A; S2: At room temperature, the obtained epoxy mixture A was mixed with 2.8 g of hollow glass microspheres and 4.6 g of polytetrafluoroethylene powder to obtain a mixture B, wherein the ratio of epoxy resin, anhydride curing agent, catalyst, hollow glass microspheres, and polytetrafluoroethylene in the mixture B was 95:88:1:28:46; Preferably, the hollow glass microspheres have a particle size of 80-120 μm and a density of 0.20 g / cm 3 .

[0056] S3: Mixture B was mechanically stirred uniformly in a planetary mixer at 100° C., with a stirring speed of 400 r / min and a stirring time of 120 s in the first stage; a stirring speed of 600 r / min and a stirring time of 180 s in the second stage; a stirring speed of 800 r / min and a stirring time of 300 s in the third stage; a stirring speed of 700 r / min and a stirring time of 120 s in the fourth stage; and a stirring speed of 600 r / min and a stirring time of 60 s in the fifth stage. After the stirring was completed, vacuum degassing was performed to obtain a mixed solution C; S4: The mixed solution C is loaded into a cavity with a high-speed rotating blade, and the principle of fluid shear thinning is used to thin the solution with high viscosity, and then sprayed onto the surface of the insulator through a high-pressure spray gun; S5: subjecting the insulator to high-temperature curing treatment, wherein the first curing temperature is 80°C and the curing time is 2 hours; the second curing temperature is 120°C and the curing time is 4 hours; and the third curing temperature is 150°C and the curing time is 4 hours, thereby obtaining the insulator low dielectric coating 3.

[0057] The dielectric constant and dielectric loss tangent of coating 3 are as follows: Figure 3 shown.

[0058] Comparative Example 1 S1: At room temperature, 10.0 g of E51 epoxy resin, 8.6 g of methylhexahydrophthalic anhydride curing agent, and 0.1 g of 2,4,6-tris(dimethylaminomethyl)phenol were mixed to obtain epoxy mixture A; S2: At room temperature, the obtained epoxy mixture A was mixed with 38.6 g of oven-dried alumina powder to obtain a mixture B, wherein the ratio of epoxy resin, anhydride curing agent, catalyst, and alumina in the mixture B was 100:86:1:38; Preferably, the particle size of the aluminum oxide powder is 30-80 μm and the density is 3.86 g / cm 3 .

[0059] S3: Mixture B was mechanically stirred uniformly in a planetary mixer at 100° C., with a stirring speed of 400 r / min and a stirring time of 120 s in the first stage; a stirring speed of 600 r / min and a stirring time of 180 s in the second stage; a stirring speed of 800 r / min and a stirring time of 300 s in the third stage; a stirring speed of 700 r / min and a stirring time of 120 s in the fourth stage; and a stirring speed of 600 r / min and a stirring time of 60 s in the fifth stage. After the stirring was completed, vacuum degassing was performed to obtain a mixed solution C; S4: The mixed solution C is loaded into a cavity with a high-speed rotating blade, and the principle of fluid shear thinning is used to thin the solution with high viscosity, and then sprayed onto the surface of the insulator through a high-pressure spray gun; S5: subjecting the insulator to high-temperature curing treatment, wherein the first curing temperature is 80°C and the curing time is 2 hours; the second curing temperature is 120°C and the curing time is 4 hours; and the third curing temperature is 150°C and the curing time is 4 hours, thereby obtaining the insulator low dielectric coating 4.

[0060] The dielectric constant and dielectric loss tangent of coating 4 are as follows: Figure 4 shown.

[0061] Table 1 below shows the analysis results of the dielectric constant and dielectric loss tangent of the low dielectric coatings prepared using Examples 1 to 3 of the present invention and Comparative Example 1 at 50 Hz.

[0062] Table 1

[0063] Table 1 shows that the low-dielectric coatings produced in Examples 1, 2, and 3 exhibit low dielectric constants and excellent dielectric properties. Compared to the comparative example, which uses alumina, a commonly used insulating composite material, instead of hollow glass microspheres, the dielectric constant is over 54% lower. The comparative example exhibits a low dielectric loss tangent, while the dielectric loss tangent of the examples is within the normal application range.

[0064] In summary, the present invention discloses a low-dielectric coating material for insulator surfaces, its preparation method, and its application. This material utilizes a composite system of an epoxy resin matrix and hollow glass microspheres / polytetrafluoroethylene (PTFE) powder. This system achieves low dielectric properties through a single mixing step, eliminating the need for complex modification steps. High-temperature vacuum ultrasonic stirring combined with vacuum degassing effectively eliminates internal porosity, improves coating density, and shortens the preparation cycle to within 30 minutes, completing mixing and degassing. The raw materials used are bisphenol A / F epoxy resin, a conventional amine curing agent, and industrial-grade hollow glass microspheres—all mature industrial raw materials, resulting in a cost reduction of approximately 40% compared to nanofillers. PTFE powder, as a reinforcing phase, has both low dielectric constant and high chemical stability, reducing long-term maintenance costs; hollow glass microspheres reduce material density and dielectric constant, while PTFE inhibits charge accumulation. The synergistic effect increases the surface resistivity of the coating by more than 30%, and the surface flashover voltage is significantly enhanced; the spraying process is combined with high-temperature curing (such as 120°C) to ensure that the interfacial bonding strength between the coating and the substrate reaches more than 15MPa, avoiding peeling problems; by limiting the filler particle size and ratio, the dielectric gradient distribution is achieved and the electric field uniformity is optimized; the dynamic stirring rate of 400-800r / min ensures uniform dispersion of the filler, and the surface roughness is controlled at Ra≤0.5μm, reducing the risk of partial discharge; the combination of process simplicity, cost-effectiveness and performance improvement solves the problems of uneven morphology and poor adhesion of traditional coatings, providing a feasible solution for the application of UHV insulator engineering.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a low dielectric coating material on an insulator surface, characterized in that: The following steps are involved: At room temperature, an epoxy resin, a curing agent and a catalyst are mixed to obtain an epoxy mixture, and the epoxy mixture is mixed with hollow glass microspheres or polytetrafluoroethylene powder to obtain a mixture; Under a high-temperature vacuum environment, the obtained mixture is subjected to ultrasonic stirring and vacuum degassing to obtain a coating mixed solution; The coating mixture solution is sprayed onto the surface of the insulator to be coated through a high-pressure spray gun, and a low-dielectric coating for the insulator is obtained after high-temperature curing.

2. The method for preparing a low dielectric coating material on an insulator surface according to claim 1, characterized in that: By weight, the epoxy resin is 90-100 parts, the curing agent is 86-90 parts, and the catalyst is 1-2 parts; wherein the epoxy resin is bisphenol A diglycidyl ether type, bisphenol F diglycidyl ether type or hydrogenated bisphenol A diglycidyl ether type epoxy; The curing agent is an amine curing agent, an acid anhydride curing agent or an active ester curing agent; The catalyst is 2,4,6-tris(dimethylaminomethyl)phenol, 2-ethyl-4-methylimidazole and 2-phenylimidazole.

3. The method for preparing a low dielectric coating material on an insulator surface according to claim 2, characterized in that: By weight, the hollow glass microspheres are 20 to 30 parts, and the polytetrafluoroethylene powder is 40 to 60 parts.

4. The method for preparing a low dielectric coating material on an insulator surface according to claim 3, characterized in that: The particle size of hollow glass microspheres is 15~135μm and the density is 0.125~0.60g / cm 3 .

5. The method for preparing a low dielectric coating material on an insulator surface according to claim 4, characterized in that: The particle size of hollow glass microspheres is 30~120μm and the density is 0.20g / cm 3 .

6. The method for preparing a low dielectric coating material on an insulator surface according to claim 2, characterized in that: The particle size of PTFE powder is 1~50μm and the density is 2.0~3.0g / cm 3 .

7. The method for preparing a low dielectric coating material on an insulator surface according to claim 6, characterized in that: The particle size of polytetrafluoroethylene powder is 10~20μm and the density is 2.3g / cm 3 .

8. The method for preparing a low dielectric coating material on an insulator surface according to claim 1, characterized in that: The stirring temperature of ultrasonic stirring is 80~150℃, the stirring rate is 400~800r / min, and the stirring time is 10~15min.

9. A low dielectric coating material on the surface of an insulator prepared according to the method of any one of claims 1 to 8.

10. Use of the low-dielectric coating material on the surface of an insulator according to claim 9 in electronic devices and insulation systems.

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