Gas insulated metal enclosed switchgear flange protection material, and preparation method and field detection method thereof

Abstract

The application belongs to the technical field of protective materials, and relates to a gas insulated metal enclosed switchgear flange protective material and a preparation method and on-site detection method thereof. The protective material comprises, in mass parts, 100 parts of a base material, 65-85 parts of modified fillers, 10-20 parts of modified pigments, 0.5-1.5 parts of additives, 90-110 parts of dispersants, 15-40 parts of crosslinking agents / flame retardants, and 0.3-0.5 parts of catalysts. The protective material provided by the application uses a new high-temperature self-cleavage curing agent for silicone rubber which does not depend on phosphorus elements as a flame-retardant component and is combined with modified fillers with long chains of surface-grafted flexible polydimethylsiloxane, realizes long-term stable dispersion of the flame-retardant component and the modified fillers through chemical bonding between the flame-retardant component and the silicone rubber matrix, and significantly improves the mechanical properties and durability of the coating. A new RTV silicone rubber-based flame-retardant and corrosion-resistant composite coating prepared from the protective material is suitable for the protection of GIS flanges.

Description

Technical Field

[0001] This invention belongs to the field of protective materials technology, and relates to a gas-insulated metal-enclosed flange protective material for switchgear, its preparation method and on-site testing method. Background Technology

[0002] Gas-insulated metal-enclosed switchgear (GIS) uses SF6 gas or similar as the insulating medium to enclose multiple components within a grounded metal housing, enabling it to control, monitor, protect, and switch power transmission. Due to its small footprint, ease of maintenance, and long service life, it has gained widespread application in recent years and has become a key piece of equipment in power grids.

[0003] Gas-insulated sealed switchgear includes multiple devices such as busbars, isolating grounding switches, and circuit breakers. Due to the needs of equipment connection and integration, there are numerous flange joint structures between gas chambers and in locations such as maintenance access holes. The performance of these flange structures directly affects the safe and stable operation of the equipment. Since gas-insulated metal-enclosed switchgear operates in the atmospheric environment, it is inevitably affected by atmospheric corrosion. In complex environments, such as extreme cold, high humidity, pollution, and high altitudes, environmental corrosion damage, material deterioration, and uneven thermal expansion of components can also lead to material deterioration and damage. Especially for GIS flange joint areas, due to their complex structure including bolts, bolt holes, welds, mating surfaces, and expansion joint bellows, they often become the first areas where material damage and corrosion deterioration occur. For example, outdoor GIS flanges operating in heavy industrial areas have experienced severe corrosion problems due to corrosion, ultimately leading to air leakage defects; there have also been cases where rainwater seeped into the mating surfaces of outdoor GIS flanges in winter, froze, and expanded, causing air leakage at the flange mating surfaces. Typical cases show that corrosion can lead to flange seal failure and SF6 leakage, while moisture seeping into the mating surface, freezing and expanding can directly cause seal damage, threatening the insulation performance and operational safety of the equipment.

[0004] Current engineering primarily relies on acrylic and other anti-corrosion coatings applied during the manufacturing stage. However, these methods have revealed significant shortcomings during long-term operation: 1) The flange area of ​​GIS is generally treated by shot blasting followed by brushing with acrylic or other anti-corrosion paints during the manufacturing stage. This lack of effective heavy-duty anti-corrosion technology for flange structures is problematic in highly corrosive environments such as high temperature, high humidity, and high salt. 2) The flange area contains numerous gaps, such as bolt holes and mating surfaces, making it prone to crevice corrosion. Effective maintenance and protection measures are lacking. 3) For expansion joint flanges in GIS, the complex structure, including bellows and long bolts, presents significant challenges for protective construction. 4) Existing maintenance-stage anti-corrosion measures involving brushing paint are prone to paint peeling and damage. Furthermore, this method requires destructive testing to check the coating's effectiveness, and the damaged coating is difficult to restore, hindering the assessment of its protective effect.

[0005] Room temperature vulcanizing (RTV) silicone rubber, due to its unique molecular structure and properties, has become an ideal material for solving the aforementioned problems. Its main chain consists of compliant Si-O-Si bonds with long bond lengths and large bond angles, resulting in strong molecular chain segment mobility. Through cross-linking, it forms a three-dimensional network structure. The cross-linking points provide shape memory and resistance to permanent deformation, while the long chain segments impart high elasticity. This structure allows RTV coatings to adhere tightly to metal substrates and respond elastically to flange deformation, achieving adaptive coating and gap sealing for complex geometries. Simultaneously, silicone rubber has extremely low surface energy, exhibits strong hydrophobicity, and a large contact angle, making it difficult for moisture to spread and wet, physically preventing the formation of electrolyte solutions and suppressing the risks of electrochemical corrosion and icing expansion. Its chemical inertness also ensures long-term stability under ozone and ultraviolet light.

[0006] However, silicone rubber itself is a flammable material, and its flame retardancy rating must be improved when used in electrical equipment. Flame retardant modification faces unique challenges: the low surface energy and non-polarity of silicone rubber result in poor compatibility with most inorganic flame retardants, making it prone to migration and precipitation. Traditional flame retardant mechanisms require targeted optimization. Gas-phase flame retardancy relies on free radical capture (such as phosphorus and nitrogen compounds); condensed-phase flame retardancy requires the use of platinum-based or transition metal compounds to promote the formation of ceramic barriers; cooling-dilution flame retardants (such as aluminum hydroxide) require surface modification to improve dispersion; and physical barrier fillers (such as montmorillonite) require optimization of exfoliation and interfacial bonding. Therefore, developing multifunctional additives that are chemically bonded to the silicone rubber matrix and possess both curing and flame-retardant functions to achieve intrinsic flame retardancy is key to achieving long-lasting flame retardancy.

[0007] Furthermore, to meet the stringent mechanical performance requirements of power equipment, fillers must be introduced into the silicone rubber matrix. This also presents a fundamental challenge: the extremely low surface energy of silicone rubber is thermodynamically incompatible with most inorganic fillers, leading to filler agglomeration and weak interfacial bonding, severely impairing the coating's uniformity, mechanical strength, and long-term reliability. Therefore, enhancing the compatibility between the filler and the matrix through interfacial modification has become crucial for developing high-performance silicone rubber materials. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a protective material for gas-insulated metal-enclosed switchgear flanges, along with its preparation and on-site testing methods. The protective material provided by this invention utilizes a novel phosphorus-free silicone rubber with a high-temperature self-destructive curing agent as the flame-retardant component, combined with a surface-grafted flexible polydimethylsiloxane (PDMS) long-chain modified filler. Through chemical bonding between the flame-retardant component and the silicone rubber matrix, long-term stable dispersion of the flame-retardant component and the modified filler is achieved, significantly improving the mechanical properties and durability of the coating. A novel RTV silicone rubber-based flame-retardant and corrosion-resistant composite coating, further prepared from this protective material, is suitable for the protection of GIS flanges.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, a gas-insulated metal-enclosed flange protection material for switchgear includes component A and component B; By mass, component A comprises 100 parts of base material, 65-85 parts of modified filler, 10-20 parts of modified pigment, 0.5-1.5 parts of additives, and 90-110 parts of dispersant; component B comprises 15-40 parts of crosslinking agent / flame retardant and 0.3-0.5 parts of catalyst. The chemical structure of the crosslinking agent / flame retardant is shown below: R and R' are independently selected from methyl, ethyl, and propyl, respectively; the base material includes hydroxyl-containing fluorinated modified silicone rubber; the modified filler is a filler with surface-grafted flexible polydimethylsiloxane chains, and the pigment is a pigment with surface-grafted flexible polydimethylsiloxane chains.

[0010] This invention selects hydroxyl-containing fluorinated modified silicone rubber. Firstly, the Si-O backbone of silicone rubber endows the material with excellent flexibility, resistance to high and low temperatures, and physiological inertness. Secondly, fluorination modification gives the silicone rubber fluorinated side groups, and the strong electronegativity of fluorine atoms greatly enhances the material's resistance to oils and non-polar solvents. Thirdly, hydroxyl groups can react with silicon-oxygen bonds under the action of a catalyst, providing a basis for the subsequent design of crosslinking agents / flame retardants. The crosslinking agent / flame retardant provided by this invention simultaneously comprises triazine structural units and monoalkoxysilane coupling agent fragments. The triazine unit plays a dual role: first, it possesses flame retardant capabilities, decomposing at approximately 250°C to produce inert gases such as ammonia and carbon dioxide. These gases dilute the surrounding oxygen concentration, extinguishing the flame due to oxygen deficiency; second, its chemical structure contains multiple silicon-oxygen bonds, which can react with hydroxyl groups in the matrix material under the action of a catalyst, causing the silicone rubber to solidify into a three-dimensional network. At this point, the triazine structure becomes a key node in the three-dimensional network. Once the high temperature triggers the curing agent's self-decomposition, the network structure disintegrates prematurely, causing the burning portion in the matrix to separate from the polymer body under the impetus of the inert gas, thus achieving an active flame retardant mechanism. Therefore, the intrinsically flame-retardant silicone rubber material formed by the catalytic curing reaction of this crosslinking agent / flame retardant and hydroxyl-containing fluorinated modified silicone rubber overcomes the shortcomings of traditional flame retardant methods, such as excessive flame retardant addition and easy degradation of matrix mechanical properties, significantly improving the overall performance of silicone rubber.

[0011] The modified filler provided by this invention effectively reduces the interfacial energy between the filler and the silicone rubber matrix by surface grafting with long-chain polydimethylsiloxane (PDMS) using the principle of "like dissolves like," and establishes a strong and tough anchoring interface through the long-chain entanglement structure. This fundamentally eliminates filler agglomeration, transforming it from a mechanical defect point into a reinforcing point, ensuring the high elasticity and processability of the coating.

[0012] Furthermore, GIS protection, especially GIS flange protection, requires consideration of the complexity of the equipment structure. This necessitates the development of specialized coating materials that combine elasticity, good adhesion, and excellent corrosion resistance. Therefore, pigments, additives, and dispersants are also required to meet these demands. Pigments are primarily used for coating coloring. Added inorganic pigments, along with other functional fillers, synergistically enhance the coating's flame retardancy and corrosion resistance. Modifying pigments using the same method as filler modification—specifically, through long-chain surface grafting modification of the filler with polydimethylsiloxane (PDMS)—effectively reduces the interfacial energy with the silicone rubber matrix using the "like dissolves like" principle. The long-chain entanglement structure creates a strong anchoring interface, fundamentally eliminating pigment agglomeration and thus better synergistically interacting with the modified filler. Additives and dispersants improve the state and stability of the coating system, resulting in coatings with low defects, uniformity, and stable performance.

[0013] Secondly, a method for preparing the gas-insulated metal-enclosed switchgear flange protective material as described in the first aspect of the present invention includes the following steps: The modified filler is added to the dispersant and mixed evenly to obtain a primary dispersion; Add the modified pigment to the primary dispersion and mix thoroughly to obtain a secondary dispersion; Add an auxiliary agent to the secondary dispersion and mix thoroughly to obtain a tertiary dispersion; Add the base material to the three-stage dispersion and mix thoroughly to obtain component A; The crosslinking agent / flame retardant is mixed evenly with the catalyst to obtain component B.

[0014] Adding the components sequentially during the preparation of component A ensures uniform mixing and facilitates the effective action of each component.

[0015] Thirdly, a field construction method for flange protection of gas-insulated metal-enclosed switchgear includes surface treatment and coating construction. Surface treatment includes the following steps: The cylindrical area on the flange side and the substrate are mechanically polished, cleaned, and dried. Remove the peeling or flaking coating from the middle area of ​​the flange, clean and dry it, and then apply a release agent. The joint area of ​​the flange mating surface is protected by wrapping with sealing tape; The painting process includes the following steps: The gas-insulated metal-enclosed switchgear flange protection material according to the first aspect of the present invention is provided by compounding component A and component B. The mixed material is applied to the surface of the gas-insulated metal-enclosed switchgear flange after surface treatment.

[0016] Fourthly, a field testing method for the curing degree of flange protection material is provided, which combines the "finger pressure method" and the "needle penetration method" to test its curing degree; The "finger pressure method" is used to measure surface dryness, and its steps are as follows: (1) First, after the coating material is applied and cured, use the pad of your index finger to "lightly press and slide"; (2) If there is sticky substance on your fingers after lightly pressing and touching, it means that the coating has not been cured; otherwise, it has been "surface dry". (3) If the coating wrinkles and cracks after sliding, it means that the coating is not well cured inside; otherwise, the surface is dry. The "acupuncture method" is used to measure actual strength, and its steps are as follows: (1) After the surface drying time is set, the needle is slowly inserted in a direction perpendicular to the coating surface; (2) Pull out the needle that has been inserted into the coating. If the needle cannot be inserted normally or is difficult to insert and no adhesive material adheres when pulled out, it indicates that the coating has been cured well. Otherwise, it has not been fully cured.

[0017] The beneficial effects of this invention are as follows: 1. Achieve long-lasting, reliable, and maintainable comprehensive protection: The coating, based on highly elastic room-temperature vulcanizing silicone rubber, exhibits strong adhesion to metals and combines excellent chemical inertness and hydrophobicity. It effectively seals complex structures, withstands environmental deformation, and fundamentally inhibits the risk of corrosion and icing. The coating can be peeled off for inspection and easily repaired, enabling visual assessment of the protection status and long-term maintenance. It is suitable for on-site application to both new and old equipment.

[0018] 2. Overcoming the challenges of flame retardant compatibility and high-efficiency flame retardancy in silicone rubber systems: Molecular design was used to achieve good compatibility and long-term stability between the flame retardant components and the silicone rubber matrix, preventing migration and precipitation. While maintaining the material's elasticity, a synergistic mechanism of non-phosphorus gas-phase flame retardancy and self-decomposition was employed to endow silicone rubber with intrinsic flame retardant properties, significantly improving its flame retardant rating.

[0019] 3. Achieving high performance and functional integration of fillers: By performing long-chain surface grafting modification of the filler with polydimethylsiloxane (PDMS), the interfacial energy between it and the silicone rubber matrix is ​​effectively reduced using the principle of "like dissolves like," and a strong and tough anchoring interface is built through the long-chain entanglement structure. This fundamentally eliminates filler agglomeration, transforming it from a mechanical defect point into a reinforcing point, ensuring the high elasticity and processability of the coating. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 These are schematic diagrams illustrating the modification of the modified fillers or pigments in Examples 1-8 of the present invention. Figure 2 This is a synthetic route diagram of the flame retardant / crosslinking agent Mel-tSi prepared in Example 9 of the present invention; Figure 3 This is a schematic diagram of the brushing and grinding areas of the flange in the field construction method of the experimental example of the present invention; Figure 4 This is a schematic diagram of the brushing and grinding areas of the flange component in the on-site construction method of the experimental example of the present invention; Figure 5 The images shown are (a) the appearance after curing and (b) the result of non-destructive peeling inspection of the test example of the present invention. Detailed Implementation

[0022] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Given the high protection requirements for GIS flanges, this invention proposes a protective material for gas-insulated metal-enclosed switchgear flanges, its preparation method, and its on-site testing method.

[0025] A typical embodiment of the present invention provides a gas-insulated metal-enclosed flange protection material for switchgear, comprising component A and component B; By mass, component A comprises 100 parts of base material, 65-85 parts of modified filler, 10-20 parts of modified pigment, 0.5-1.5 parts of additives, and 90-110 parts of dispersant; component B comprises 15-40 parts of crosslinking agent / flame retardant and 0.3-0.5 parts of catalyst. The chemical structure of the crosslinking agent / flame retardant is shown below: R and R' are independently selected from methyl, ethyl, and propyl, respectively; the base material is hydroxyl-containing fluorinated modified silicone rubber; the modified filler is a filler with surface-grafted flexible polydimethylsiloxane chains; and the pigment is a pigment with surface-grafted flexible polydimethylsiloxane chains.

[0026] In some embodiments, the base material further includes one or more of room temperature vulcanizing silicone rubber, fluorosilicone rubber, and hydroxyl-terminated silicone rubber. The hydroxyl-terminated groups are highly reactive and can react with a crosslinking agent at room temperature to achieve room temperature vulcanization, making it ideal for on-site application. Specifically, the mass ratio of hydroxyl-terminated silicone rubber to hydroxyl-containing fluorinated modified silicone rubber is 5-2:1, preferably 2:1. Specifically, the viscosity of the room temperature vulcanizing silicone rubber is 5000-6000 mPa·s. Specifically, the viscosity of the fluorosilicone rubber is 5000-6000 mPa·s. Specifically, the viscosity of the hydroxyl-terminated silicone rubber is 5000-6000 mPa·s.

[0027] In some embodiments, the modified filler includes modified anti-settling filler and modified reinforcing filler, with a mass ratio of 3-5:62-80. Specifically, the modified anti-settling filler is modified nano-silica. More specifically, the particle size of the modified nano-silica is 10-45 nm. Specifically, the modified reinforcing filler is modified micron-sized silica and / or modified chopped fiber material. More specifically, the particle size of the modified micron-sized silica is 2-5 μm. More specifically, the length of the modified chopped fiber material is 0.5-3 mm. The chopped fiber is one or more combinations of glass fiber, carbon fiber, and polyaramid fiber.

[0028] In some embodiments, the modification method of the modified filler includes the following steps: Solution a is prepared by dissolving hydroxyl-terminated siloxanes in an anhydrous organic solvent; The filler was uniformly dispersed in an anhydrous organic solvent to obtain filler dispersion b; Solution a is added to filler dispersion b, acid solution is added, and the grafting reaction is carried out by heating to obtain the final product.

[0029] Specifically, ultrasonic treatment during the preparation of solution a is beneficial for the uniform dispersion of hydroxyl-terminated siloxanes.

[0030] Specifically, the hydroxyl-terminated siloxane is any one or more oligomers with Si-O-Si as the main chain, hydroxyl as the terminal group, and Si-F as the side group, with a relative molecular mass of 425~4000 g / mol (viscosity of 3~50 centistokes).

[0031] Specifically, the mass ratio of hydroxyl-terminated siloxane to anhydrous organic solvent is 1:20~100.

[0032] Specifically, the anhydrous organic solvent is any one or more of ethyl acetate, tetrahydrofuran, butyl acetate, xylene, dioxane, and ethyl formate.

[0033] Specifically, ultrasonic treatment is performed during the preparation of filler dispersion b.

[0034] Specifically, the mass ratio of the filler to the anhydrous organic solvent is 1:20~50.

[0035] Specifically, the mass ratio of hydroxyl-terminated siloxane to filler is 1:15~35.

[0036] Specifically, the hydrogen ion concentration of the acid solution is 0.005~0.015 M. The concentration unit M represents mol / L. The amount of acid solution added is 1~5 drops.

[0037] Specifically, the grafting reaction temperature is 45~55℃, and the reaction time is 1.5~2.5h.

[0038] Specifically, after the grafting reaction, the reaction solution is filtered to remove the solvent, washed successively with ethyl acetate, water, and anhydrous ethanol, and dried at room temperature. The drying time at room temperature is 20-30 hours.

[0039] In some embodiments, the modified pigment is one or a combination of several of the following: modified iron oxide red powder (for the preparation of red paint), modified white titanium dioxide powder (for the preparation of white paint), modified carbon black powder (for the preparation of black paint), modified iron oxide yellow powder (for the preparation of yellow paint), and modified Prussian blue powder (for the preparation of blue paint). The modification method for the modified pigment is the same as the modification method for the modified filler, which includes the following steps: Solution a is prepared by dissolving hydroxyl-terminated siloxanes in an anhydrous organic solvent; The pigment was uniformly dispersed in an anhydrous organic solvent to obtain pigment dispersion b; Add solution a to pigment dispersion b, add acid solution, and heat to carry out grafting reaction to obtain the final product.

[0040] Specifically, ultrasonic treatment during the preparation of solution a is beneficial for the uniform dispersion of hydroxyl-terminated siloxanes.

[0041] Specifically, the hydroxyl-terminated siloxane is any one or more oligomers with Si-O-Si as the main chain, hydroxyl as the terminal group, and Si-F as the side group, with a relative molecular mass of 425~4000 g / mol (viscosity of 3~50 centistokes).

[0042] Specifically, the mass ratio of hydroxyl-terminated siloxane to anhydrous organic solvent is 1:20~100.

[0043] Specifically, the anhydrous organic solvent is any one or more of ethyl acetate, tetrahydrofuran, butyl acetate, xylene, dioxane, and ethyl formate.

[0044] Specifically, the pigment dispersion b is subjected to ultrasonic treatment during its preparation.

[0045] Specifically, the mass ratio of pigment to anhydrous organic solvent is 1:20~50.

[0046] Specifically, the mass ratio of hydroxyl-terminated siloxane to filler is 1:15~35.

[0047] Specifically, the hydrogen ion concentration of the acid solution is 0.005~0.015 M. The concentration unit M represents mol / L. The amount of acid solution added is 1~5 drops.

[0048] Specifically, the grafting reaction temperature is 45~55℃, and the reaction time is 1.5~2.5h.

[0049] Specifically, after the grafting reaction, the reaction solution is filtered to remove the solvent, washed successively with ethyl acetate, water, and anhydrous ethanol, and dried at room temperature. The drying time at room temperature is 20-30 hours.

[0050] In some embodiments, the additives include 0.1 to 0.3 parts of defoamer, 0.3 to 0.9 parts of wetting and dispersing agent, and 0.1 to 0.3 parts of leveling agent.

[0051] Specifically, the defoamer is one or more of the following: fatty alcohol polyoxyethylene ether, lauryl glucoside, polyethylene oxide silicone oil, and defoaming polysiloxane solution.

[0052] Specifically, the wetting and dispersing agent is one or more of the following: modified acrylate block copolymer, methylpentanol, and fatty acid polyethylene glycol ester.

[0053] Specifically, the leveling agent is one or more of polymethylphenylsiloxane, acrylate copolymer solution, and dimethyl silicone oil.

[0054] Specifically, the dispersant is one or more of butyl acetate, ethyl acetate, and xylene. When multiple dispersants are used, the preferred mass ratio of butyl acetate, ethyl acetate, and xylene is 3:4.5~5.5:1.8~2.2; the preferred mass ratio of butyl acetate to ethyl acetate is 3:6.5~7.5; the optimal mass ratio of ethyl acetate to xylene is 2:2.7~3.3; and the preferred mass ratio of butyl acetate to xylene is 3:1.8~2.2.

[0055] In some embodiments, the preparation method of the crosslinking agent / flame retardant includes the following steps: Add cyanuric chloride and triethylamine to an anhydrous solvent and mix well to obtain solution A; Under conditions below room temperature, an aminodiakoxysilane coupling agent was slowly added to solution A, and the solution was restored to room temperature to carry out the reaction, thereby obtaining reaction solution B. The aminomonoalkoxysilane coupling agent is slowly added to reaction solution B, and the mixture is heated to 70-75°C to carry out the reaction, thus obtaining the product.

[0056] Specifically, the molar ratio of cyanuric chloride to triethylamine is 1:3~5.

[0057] Specifically, the molar ratio of cyanuric chloride to aminodiakoxysilane coupling agent is 1:0.9~1.1.

[0058] Specifically, the molar ratio of cyanuric chloride to aminomonoalkoxysilane coupling agent is 1:1.8~2.2.

[0059] Specifically, the reaction time at room temperature is 8-12 hours; Specifically, the heating reaction time is 8~12 hours; Specifically, the anhydrous solvent is any one or more of tetrahydrofuran, dioxane, acetone, chloroform, etc.

[0060] Specifically, the aminodialkoxysilane coupling agent is one or more of 3-aminopropyldimethoxymethylsilane and 3-aminopropyldiethoxymethylsilane.

[0061] Specifically, the aminomonoalkoxysilane coupling agent is one or more of 3-aminopropylmethoxydimethylsilane and 3-aminopropylethoxydimethylsilane.

[0062] Specifically, the purification process after heating the reaction is as follows: after the reaction is complete, the precipitate is removed by filtration, the solvent is removed by vacuum distillation of the obtained filtrate, and then recrystallized with methanol and dried. The drying parameters are 60~80℃ and 10~20h.

[0063] The catalyst of this invention is used to control the curing rate. In some embodiments, the catalyst is dibutyltin dilaurate or dibutyltin diacetate.

[0064] Another embodiment of the present invention provides a method for preparing the above-mentioned gas-insulated metal-enclosed switchgear flange protective material, comprising the following steps: The modified filler is added to the dispersant and mixed evenly to obtain a primary dispersion; Add the modified pigment to the primary dispersion and mix thoroughly to obtain a secondary dispersion; Add an auxiliary agent to the secondary dispersion and mix thoroughly to obtain a tertiary dispersion; Add the base material to the three-stage dispersion and mix thoroughly to obtain component A; The crosslinking agent / flame retardant is mixed evenly with the catalyst to obtain component B.

[0065] In some embodiments, ultrasonic treatment is performed during the preparation of a primary dispersion. Specifically, the ultrasonic treatment time is 0.1 to 0.3 h.

[0066] In some embodiments, ultrasonic treatment is performed during the preparation of the secondary dispersion. Specifically, the ultrasonic treatment time is 0.4 to 0.6 hours.

[0067] In some embodiments, a stirring dispersion treatment is performed during the preparation of the three-stage dispersion. Specifically, the stirring dispersion treatment time is 0.4 to 0.6 hours.

[0068] In some embodiments, after adding the base material to the three-stage dispersion, a shear dispersion treatment is performed first, followed by a stirring dispersion treatment. Specifically, the shear dispersion treatment time is 0.4~0.6 h. Specifically, the stirring dispersion treatment time is 2.5~3.5 h.

[0069] A third embodiment of the present invention provides an on-site construction method for flange protection of gas-insulated metal-enclosed switchgear, including surface treatment and coating construction; Surface treatment includes the following steps: The cylindrical area on the flange side and the substrate are mechanically polished, cleaned, and dried. Remove the peeling or flaking coating from the middle area of ​​the flange, clean and dry it, and then apply a release agent. The joint area of ​​the flange mating surface is protected by wrapping with sealing tape; The painting process includes the following steps: Provide the above-mentioned gas-insulated metal-enclosed switchgear flange protection material, and mix component A and component B into an adhesive; The mixed material is applied to the surface of the gas-insulated metal-enclosed switchgear flange after surface treatment.

[0070] In some embodiments, the length of the polishing area for mechanical polishing is 50~200mm, and the surface roughness is Ra 15~80μm.

[0071] In some embodiments, after mechanical polishing, the surface is first rinsed with water, then rinsed with alcohol with a purity of not less than 95%, and then cleaned with a hot air gun.

[0072] In some embodiments, after removing the peeling or flaking coating from the middle area of ​​the flange, it is rinsed clean with water, purified water, and alcohol respectively, and then dried with a hot air gun.

[0073] In some embodiments, the mold release agent is dimethyl silicone oil (molecular weight less than 2000) or paraffin wax.

[0074] In some embodiments, after coating application, the final coating thickness is 0.5~5mm, and the air spraying parameters are a pressure of 0.3~0.7MPa and a spraying flow rate of 10~200ml / min.

[0075] The fourth embodiment of the present invention provides an on-site testing method for the curing degree of flange protective material, which uses a combination of "finger pressure method" and "needle penetration method" to test its curing degree; The "finger pressure method" is used to measure surface dryness, and its steps are as follows: (1) First, after the coating material is applied and cured, use the pad of your index finger to "lightly press and slide"; (2) If there is sticky substance on your fingers after lightly pressing and touching, it means that the coating has not been cured; otherwise, it has been "surface dry". (3) If the coating wrinkles and cracks after sliding, it means that the coating is not well cured inside; otherwise, the surface is dry. The "acupuncture method" is used to measure actual strength, and its steps are as follows: (1) After the surface drying time is set, the needle is slowly inserted in a direction perpendicular to the coating surface; (2) Pull out the needle that has been inserted into the coating. If the needle cannot be inserted normally or is difficult to insert and no adhesive material adheres when pulled out, it indicates that the coating has been cured well. Otherwise, it has not been fully cured.

[0076] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0077] Example 1 ① Dissolve 2g of hydroxyl-terminated dimethylsiloxane in 50ml of anhydrous tetrahydrofuran and sonicate thoroughly to prepare solution a.

[0078] ② Disperse 30g of 30nm silica in 600ml of anhydrous tetrahydrofuran using ultrasonication to obtain filler dispersion b.

[0079] ③ Add solution a to the filler dispersion b, add 1 drop of dilute sulfuric acid (0.01M), stir thoroughly at 50℃ for 2 hours, and allow to cool naturally to room temperature after grafting.

[0080] ④ The reaction solution was filtered to remove the solvent, then washed with ethyl acetate and dried at room temperature for 24 hours to obtain the modified filler.

[0081] Example 2 ① Dissolve 2g of hydroxyl-terminated fluorosiloxane in 50ml of anhydrous tetrahydrofuran and sonicate thoroughly to prepare solution a.

[0082] ② Disperse 30g of 4μm silica ultrasonically in 600ml of anhydrous tetrahydrofuran to obtain filler dispersion b.

[0083] ③ Add solution a to the filler dispersion b, add 1 drop of dilute sulfuric acid (0.01M), stir thoroughly at 50℃ for 2 hours, and allow to cool naturally to room temperature after grafting.

[0084] ④ The reaction solution was filtered to remove the solvent, then washed with ethyl acetate and dried at room temperature for 24 hours to obtain the modified filler.

[0085] Example 3: ① Dissolve 2g of hydroxyl-terminated fluorosiloxane in 50ml of anhydrous tetrahydrofuran and sonicate thoroughly to prepare solution a.

[0086] ② Disperse 30g of 1mm short-cut glass fibers ultrasonically in 600ml of anhydrous tetrahydrofuran to obtain filler dispersion b.

[0087] ③ Add solution a to the filler dispersion b, add 1 drop of dilute sulfuric acid (0.01M), stir thoroughly at 50℃ for 2 hours, and allow to cool naturally to room temperature after grafting.

[0088] ④ The reaction solution was filtered to remove the solvent, then washed with ethyl acetate and dried at room temperature for 24 hours to obtain the modified filler.

[0089] Example 4: ① Dissolve 2g of hydroxyl-terminated fluorosiloxane in 50ml of anhydrous tetrahydrofuran and sonicate thoroughly to prepare solution a.

[0090] ② Disperse 30g of carbon black ultrasonically in 600ml of anhydrous tetrahydrofuran to obtain pigment dispersion b.

[0091] ③ Add solution a to pigment dispersion b, add 1 drop of dilute sulfuric acid (0.01M), stir thoroughly at 50℃ for 2 hours, and allow to cool naturally to room temperature after grafting.

[0092] ④ The reaction solution was filtered to remove the solvent, then washed with ethyl acetate and dried at room temperature for 24 hours to obtain the modified pigment.

[0093] Example 5: ① Dissolve 2g of hydroxyl-terminated fluorosiloxane in 50ml of anhydrous tetrahydrofuran and sonicate thoroughly to prepare solution a.

[0094] ② Disperse 30g of iron oxide red in 600ml of anhydrous tetrahydrofuran using ultrasonication to obtain pigment dispersion b.

[0095] ③ Add solution a to pigment dispersion b, add 1 drop of dilute sulfuric acid (0.01M), stir thoroughly at 50℃ for 2 hours, and allow to cool naturally to room temperature after grafting.

[0096] ④ The reaction solution was filtered to remove the solvent, then washed with ethyl acetate and dried at room temperature for 24 hours to obtain the modified pigment.

[0097] Example 6: ① Dissolve 2g of hydroxyl-terminated fluorosiloxane in 50ml of anhydrous tetrahydrofuran and sonicate thoroughly to prepare solution a.

[0098] ② Disperse 30g of white titanium dioxide powder in 600ml of anhydrous tetrahydrofuran using ultrasonication to obtain pigment dispersion b.

[0099] ③ Add solution a to pigment dispersion b, add 1 drop of dilute sulfuric acid (0.01M), stir thoroughly at 50℃ for 2 hours, and allow to cool naturally to room temperature after grafting.

[0100] ④ The reaction solution was filtered to remove the solvent, then washed with ethyl acetate and dried at room temperature for 24 hours to obtain the modified pigment.

[0101] Example 7: ① Dissolve 2g of hydroxyl-terminated fluorosiloxane in 50ml of anhydrous tetrahydrofuran and sonicate thoroughly to prepare solution a.

[0102] ② Disperse 30g of iron oxide yellow powder in 600ml of anhydrous tetrahydrofuran using ultrasonication to obtain pigment dispersion b.

[0103] ③ Add solution a to pigment dispersion b, add 1 drop of dilute sulfuric acid (0.01M), stir thoroughly at 50℃ for 2 hours, and allow to cool naturally to room temperature after grafting.

[0104] ④ The reaction solution was filtered to remove the solvent, then washed with ethyl acetate and dried at room temperature for 24 hours to obtain the modified pigment.

[0105] Example 8: ① Dissolve 2g of hydroxyl-terminated fluorosiloxane in 50ml of anhydrous tetrahydrofuran and sonicate thoroughly to prepare solution a.

[0106] ② Disperse 30g of Prussian blue powder ultrasonically in 600ml of anhydrous tetrahydrofuran to obtain pigment dispersion b.

[0107] ③ Add solution a to pigment dispersion b, add 1 drop of dilute sulfuric acid (0.01M), stir thoroughly at 50℃ for 2 hours, and allow to cool naturally to room temperature after grafting.

[0108] ④ The reaction solution was filtered to remove the solvent, then washed with ethyl acetate and dried at room temperature for 24 hours to obtain the modified pigment.

[0109] The modification process of the modified fillers or modified pigments in Examples 1-8 is as follows: Figure 1 As shown.

[0110] Example 9: ① Add 30.2g of cyanuric chloride and 49.7g of triethylamine to 500ml of tetrahydrofuran and stir well.

[0111] ② Under ice bath conditions, 26.7 g of 3-aminopropyldimethoxymethylsilane was added to the above reaction system and stirred at room temperature for 10 h.

[0112] ③Then slowly add 48.2g of 3-aminopropylmethoxydimethylsilane to the solution in ②, then raise the temperature to 70℃ and continue the reaction for 10h; ④ The precipitate was removed by filtration, and the solvent was removed by vacuum distillation of the resulting filtrate. The precipitate was then recrystallized from methanol, and dried at 70°C for 12 hours to obtain the self-destructive flame retardant / crosslinking agent Mel-tSi. Its synthetic route is as follows: Figure 2 As shown.

[0113] The product Mel-tSi prepared in this embodiment was subjected to... 1 ¹H NMR (400 MHz, DMSO-d6) NMR spectrum analysis. The peak values ​​δ (ppm) correspond to the following values: δ 7.78 (3H), 3.35 (¹²H), 3.29–3.36 (6H), 1.50–1.59 (6H), 0.51–0.56 (6H), 0.06 (¹⁵H), which is consistent with the chemical environment of H in the product.

[0114] The following is the formulation design and preparation scheme for flange anti-corrosion materials.

[0115] Example 10: Coating Formulation: Component A: 100 parts base material, 65 parts modified filler, 10 parts modified pigment, 0.5 parts additives, and 90 parts dispersant; Component B: 17 parts curing agent. The base material is hydroxyl-containing fluorinated silicone rubber; the modified filler is 3 parts of modified nano-silica prepared in Example 1 and 62 parts of modified micron-sized silica prepared in Example 2; the modified pigment is 10 parts of modified carbon black prepared in Example 4; the additives are 0.1 parts of defoamer, 0.3 parts of wetting and dispersing agent, and 0.1 parts of leveling agent; the dispersant is 90 parts of butyl acetate; the curing agent is 16.5 parts of flame retardant / crosslinking agent Mel-tSi prepared in Example 9 and 0.5 parts of dibutyltin dilaurate.

[0116] The preparation method is as follows: (1) Add the modified filler to the dispersant and then perform ultrasonic dispersion treatment for 0.2 h to obtain a uniform primary dispersion.

[0117] (2) Then, the modified pigment is added to the dispersion in (1) and further ultrasonically dispersed for 0.5 h to obtain a secondary dispersion.

[0118] (3) Add the additive to the secondary dispersion, and then transfer it to a high-speed mixer for stirring and dispersion treatment for 0.5h.

[0119] (4) Add the base material components, and after adding them, perform shear dispersion treatment for 0.5h, and then transfer them to a high-speed mixer for further stirring and dispersion treatment for 3h; obtain coating component A.

[0120] (5) Mix the components of the curing agent evenly according to the proportion, and then seal and store to obtain component B.

[0121] Example 11 This embodiment is the same as that of Embodiment 10, except that the micron-sized silica prepared in Embodiment 2 is replaced with the modified short-cut glass fiber prepared in Embodiment 3.

[0122] Comparative Example 1 This embodiment is the same as Embodiment 10, except that the base material is changed to commercially available single-component ordinary room temperature vulcanizing silicone rubber.

[0123] Comparative Example 2 This embodiment is the same as Embodiment 10, except that the base material is changed to hydroxyl-terminated silicone rubber.

[0124] Comparative Example 3 This embodiment is the same as Embodiment 10, except that the modified filler is replaced with unmodified nano-silica and micron-silica.

[0125] Comparative Example 4 This embodiment is the same as Embodiment 10, except that the modified pigment is replaced with unmodified commercially available carbon black.

[0126] Comparative Example 5 This embodiment is the same as that of Example 10, except that the flame retardant / crosslinking agent Mel-tSi prepared in Example 9 is replaced with 5 parts of tetraethyl orthosilicate.

[0127] Comparative Example 6 This embodiment is the same as that of Example 10, except that the flame retardant / crosslinking agent Mel-tSi prepared in Example 9 is replaced with 5 parts of tetraethyl orthosilicate and 30 parts of ammonium polyphosphate.

[0128] Test case A field construction method for a gas-insulated metal-enclosed switchgear flange protection material includes: surface treatment and construction process.

[0129] (1) Surface treatment.

[0130] like Figure 3 As shown, the paint layer and substrate of the cylindrical area on the flange side are mechanically ground using an angle grinder. After grinding, the length of the ground area is 50mm-200mm, and the surface roughness requirement is Ra15-80μm. First, rinse with pure water, then rinse with alcohol with a purity of not less than 95%, and finally clean the surface with a hot air gun. For the middle and side areas of the flange, mechanical grinding is not required, but any peeling or flaking coating should be removed. Rinse thoroughly with water, pure water, and alcohol respectively, and then dry with a hot air gun. Apply a release agent to the middle and side areas. The release agent should consist of dimethyl silicone oil (molecular weight less than 2000) or paraffin wax. Figure 4 As shown, the joint area of ​​the flange mating surface is protected by wrapping a PP sealing tape around the mating surface.

[0131] (2) Construction technology The components A and B of Examples 10-11 and each comparative example were mixed to form an adhesive, and then coated by air spraying. The final thickness of the coating was 2 mm. The air spraying parameters were 0.5 MPa pressure and 100 ml / min spraying flow rate.

[0132] During protective construction, the ambient temperature must not be lower than 0 degrees Celsius. If the temperature is lower than 0 degrees Celsius, an enclosed shed must be erected to ensure that the construction temperature in the flange area is above 0 degrees Celsius.

[0133] To facilitate on-site testing of curing degree, a combination of the "finger pressure method" and the "needle penetration method" is used to test its curing degree. A method for on-site testing of the curing degree of flange protection materials includes the following steps: 1. The "finger pressure method" for measuring surface dryness: (1) After applying the coating material, let it cure for a certain period of time, then use the pad of your index finger to “lightly press and slide”.

[0134] (2) If there is sticky substance on your fingers after light touch, it means that the coating has not been cured; otherwise, it is already "surface dry".

[0135] (3) If the coating wrinkles and cracks after sliding, it means that the coating is not well cured inside; otherwise, the surface is dry.

[0136] II. Testing Practical Skills Using the "Acupuncture Method": (1) After the surface has dried for a certain period of time, use a 0.2mm needle to slowly pierce the coating surface vertically.

[0137] (2) Then pull it out. If the needle cannot be inserted normally or is difficult to insert and no adhesive material adheres when pulled out, it means that the coating has been cured well; otherwise, it has not been fully cured.

[0138] The solidified photo is as follows Figure 5 As shown.

[0139] The coatings formed in Examples 10-11 and each comparative example were subjected to performance testing, and the results are shown in Table 1.

[0140] Table 1 Performance of coatings formed in Examples 10-11 and comparative examples The tests were conducted according to the following standards: Tensile strength GB / T 529-2008 "Determination of tear strength of vulcanized rubber or thermoplastic rubber (trouser-shaped, right-angled and crescent-shaped specimens)"; Adhesion GB / T 9286-2021 "Cross-cut test of paints and varnishes"; Flame retardancy GB / T 2406.2-2009 "Determination of flammability of plastics by oxygen index method - Part 2: Room temperature test". There is no standard reference for the salt water immersion test. The test method is as follows: the specimen is immersed in a 5% sodium chloride solution at room temperature for a certain period of time, and the result is judged based on the appearance of peeling, bubbling, and flaking of the coating.

[0141] Table 1 shows that: 1) Influence of base material: The flame retardant rating of Example 10 and Comparative Example 2 is V-0, the highest level. The single-component silicone rubber of Comparative Example 1 has no rating. This is because the self-destructing flame retardant / crosslinking agent Mel-tSi of the present invention cannot be effectively introduced into the single-component silicone rubber matrix through polycondensation reaction, and cannot impart intrinsic flame retardancy. This further proves that the two-component silicone rubber using Mel-tSi as a flame retardant / curing agent can impart high-performance intrinsic flame retardancy to the silicone rubber without relying on phosphorus. Compared with Comparative Examples 1 and 2, Example 10 has better salt water immersion resistance, which is attributed to the better hydrophobicity of hydroxyl-containing fluorinated silicone rubber.

[0142] 2) Effect of filler modification: In Example 10 and Comparative Examples 3 and 4, unmodified fillers or pigments reduced the tensile strength and adhesion of the coating, indicating that long-chain PDMS modification can achieve balanced optimization of mechanical properties. Compared with Example 11, Example 10 exhibited poorer mechanical properties. This is attributed to the fact that chopped glass fibers impart better mechanical properties to silicone rubber than micron-sized silica. Chopped glass fibers achieve stress transfer and crack bridging through a high aspect ratio, and combined with the energy dissipation mechanism of interfacial pull-out, they outperform the micron-sized silica particles that act as physical crosslinking points in terms of tensile strength. 3) Influence of the flame retardant / crosslinking agent system: Compared with Comparative Examples 5 and 6, Example 10 exhibits higher flame retardant performance, indicating that the self-destructive flame retardant / crosslinking agent Mel-tSi of this invention achieves V-0 flame retardancy without compromising water corrosion resistance, which is superior to traditional phosphorus-based solutions. This is because tetraethyl orthosilicate has no flame retardant function; although ammonium polyphosphate can retard, it is highly hydrophilic, and migration leads to water absorption and coating failure. Mel-tSi achieves long-term stable dispersion of flame retardant components through chemical bonding, and the non-phosphorus self-destructive mechanism releases non-flammable gases and promotes the disintegration of the coating at high temperatures, while not introducing hydrophilic groups.

[0143] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A gas-insulated metal-enclosed flange protection material for switchgear, characterized in that, Includes component A and component B; By mass, component A comprises 100 parts of base material, 65-85 parts of modified filler, 10-20 parts of modified pigment, 0.5-1.5 parts of additives, and 90-110 parts of dispersant; component B comprises 15-40 parts of crosslinking agent / flame retardant and 0.3-0.5 parts of catalyst. The chemical structure of the crosslinking agent / flame retardant is shown below: R and R' are independently selected from methyl, ethyl, and propyl, respectively; the base material includes hydroxyl-containing fluorinated modified silicone rubber; the modified filler is a filler with surface-grafted flexible polydimethylsiloxane chains, and the pigment is a pigment with surface-grafted flexible polydimethylsiloxane chains.

2. The gas-insulated metal-enclosed switchgear flange protection material as described in claim 1, characterized in that, The base material further includes one or more of room temperature vulcanizing silicone rubber, fluorosilicone rubber, and hydroxyl-terminated silicone rubber; preferably, the mass ratio of hydroxyl-terminated silicone rubber to hydroxyl-containing fluorinated modified silicone rubber is 5~2:1, more preferably 2:1; preferably, the viscosity of the room temperature vulcanizing silicone rubber is 5000~6000 mPa·s; preferably, the viscosity of the fluorosilicone rubber is 5000~6000 mPa·s; preferably, the viscosity of the hydroxyl-terminated silicone rubber is 5000~6000 mPa·s. Alternatively, the modified filler includes modified anti-settling filler and modified reinforcing filler, with a mass ratio of 3~5:62~80; preferably, the modified anti-settling filler is modified nano-silica; preferably, the particle size of the modified nano-silica is 10~45nm; preferably, the modified reinforcing filler is modified micron-sized silica and / or modified chopped fiber material; preferably, the particle size of the modified micron-sized silica is 2~5μm; preferably, the length of the modified chopped fiber material is 0.5~3mm.

3. The gas-insulated metal-enclosed switchgear flange protection material as described in claim 1, characterized in that, The modification method for modified fillers includes the following steps: Solution a is prepared by dissolving hydroxyl-terminated siloxanes in an anhydrous organic solvent; The filler was uniformly dispersed in an anhydrous organic solvent to obtain filler dispersion b; Solution a is added to filler dispersion b, acid solution is added, and the grafting reaction is carried out by heating to obtain the final product. Preferably, ultrasonic treatment is performed during the preparation of solution a; Preferably, the hydroxyl-terminated siloxane is any one or more oligomers with Si-O-Si as the main chain, hydroxyl as the terminal group, and Si-F as the side group, with a relative molecular mass of 425~4000 g / mol and a viscosity of 3~50 centistokes. Preferably, the mass ratio of hydroxyl-terminated siloxane to anhydrous organic solvent is 1:20~100; Preferably, the anhydrous organic solvent is any one or more of ethyl acetate, tetrahydrofuran, butyl acetate, xylene, dioxane, and ethyl formate; Preferably, the filler dispersion b is subjected to ultrasonic treatment during preparation; Preferably, the mass ratio of the filler to the anhydrous organic solvent is 1:20~50; Preferably, the mass ratio of hydroxyl-terminated siloxane to filler is 1:15~35; Preferably, the hydrogen ion concentration of the acid solution is 0.005~0.015 M; Preferably, the grafting reaction temperature is 45~55℃; Preferably, the grafting reaction time is 1.5 to 2.5 hours.

4. The gas-insulated metal-enclosed switchgear flange protection material as described in claim 1, characterized in that, The modified pigment is one or a combination of several of the following: modified iron oxide red powder, modified white titanium dioxide powder, modified carbon black powder, modified iron oxide yellow powder, and modified Prussian blue powder. Alternatively, the modification method of the modified pigment may include the following steps: Solution a is prepared by dissolving hydroxyl-terminated siloxanes in an anhydrous organic solvent; The pigment was uniformly dispersed in an anhydrous organic solvent to obtain pigment dispersion b; Add solution a to pigment dispersion b, add acid solution, and heat to carry out grafting reaction to obtain the product; Preferably, ultrasonic treatment is performed during the preparation of solution a; Preferably, the hydroxyl-terminated siloxane is any one or more oligomers with Si-O-Si as the main chain, hydroxyl as the terminal group, and Si-F as the side group, with a relative molecular mass of 425~4000 g / mol and a viscosity of 3~50 centistokes. Preferably, the mass ratio of hydroxyl-terminated siloxane to anhydrous organic solvent is 1:20~100; Preferably, the anhydrous organic solvent is any one or more of ethyl acetate, tetrahydrofuran, butyl acetate, xylene, dioxane, and ethyl formate; Preferably, the pigment dispersion b is subjected to ultrasonic treatment during preparation; Preferably, the mass ratio of pigment to anhydrous organic solvent is 1:20~50; Preferably, the mass ratio of hydroxyl-terminated siloxane to filler is 1:15~35; Preferably, the hydrogen ion concentration of the acid solution is 0.005~0.015 M; Preferably, the grafting reaction temperature is 45~55℃; Preferably, the grafting reaction time is 1.5 to 2.5 hours.

5. The gas-insulated metal-enclosed switchgear flange protection material as described in claim 1, characterized in that, The additives include 0.1 to 0.3 parts of defoamer, 0.3 to 0.9 parts of wetting and dispersing agent, and 0.1 to 0.3 parts of leveling agent; Preferably, the defoamer is one or more of fatty alcohol polyoxyethylene ether, lauryl glucoside, polyethylene oxide silicone oil, and defoaming polysiloxane solution; Preferably, the wetting and dispersing agent is one or more selected from modified acrylate block copolymer, methylpentanol, and fatty acid polyethylene glycol ester; Preferably, the leveling agent is one or more of polymethylphenylsiloxane, acrylate copolymer solution, and dimethyl silicone oil; Alternatively, the dispersant may be one or more of butyl acetate, ethyl acetate, and xylene; the preferred mass ratio of butyl acetate, ethyl acetate, and xylene is 3:4.5~5.5:1.8~2.2, the preferred mass ratio of butyl acetate to ethyl acetate is 3:6.5~7.5, the optimal mass ratio of ethyl acetate to xylene is 2:2.7~3.3, and the preferred mass ratio of butyl acetate to xylene is 3:1.8~2.

2. Alternatively, the catalyst may be dibutyltin dilaurate or dibutyltin diacetate.

6. The gas-insulated metal-enclosed switchgear flange protection material as described in claim 1, characterized in that, The preparation method of the crosslinking agent / flame retardant includes the following steps: Add cyanuric chloride and triethylamine to an anhydrous solvent and mix well to obtain solution A; Under conditions below room temperature, an aminodiakoxysilane coupling agent was slowly added to solution A, and the solution was restored to room temperature to carry out the reaction, thereby obtaining reaction solution B. Slowly add aminomonoalkoxysilane coupling agent to reaction solution B, heat to 70~75℃ to carry out the reaction, and obtain the product; Preferably, the molar ratio of cyanuric chloride to triethylamine is 1:3~5; Preferably, the molar ratio of cyanuric chloride to aminodialkoxysilane coupling agent is 1:0.9~1.1; Preferably, the molar ratio of cyanuric chloride to aminomonoalkoxysilane coupling agent is 1:1.8~2.2; Preferably, the anhydrous solvent is any one or more of tetrahydrofuran, dioxane, acetone, and chloroform; Preferably, the reaction time at room temperature is 8-12 hours; Preferably, the heating reaction time is 8-12 hours; Preferably, the aminodiakoxysilane coupling agent is one or more of 3-aminopropyldimethoxymethylsilane and 3-aminopropyldiethoxymethylsilane; Preferably, the aminomonoalkoxysilane coupling agent is one or more of 3-aminopropylmethoxydimethylsilane and 3-aminopropylethoxydimethylsilane; Preferably, the purification process after heating reaction is as follows: after the reaction is completed, the precipitate is removed by filtration, the solvent is removed by vacuum distillation of the obtained filtrate, and then recrystallized with methanol and dried. Preferably, the drying parameters are 60~80℃ and 10~20h.

7. A method for preparing a gas-insulated metal-enclosed switchgear flange protective material according to any one of claims 1 to 6, characterized in that, Includes the following steps: The modified filler is added to the dispersant and mixed evenly to obtain a primary dispersion; Add the modified pigment to the primary dispersion and mix thoroughly to obtain a secondary dispersion; Add an auxiliary agent to the secondary dispersion and mix thoroughly to obtain a tertiary dispersion; Add the base material to the three-stage dispersion and mix thoroughly to obtain component A; The crosslinking agent / flame retardant is mixed evenly with the catalyst to obtain component B.

8. The preparation method according to claim 7, characterized in that, The dispersion is prepared by ultrasonic treatment; preferably, the ultrasonic treatment time is 0.1~0.3 h. Alternatively, ultrasonic treatment may be performed during the preparation of the secondary dispersion; preferably, the ultrasonic treatment time is 0.4~0.6 h; Alternatively, the mixture may be stirred and dispersed during the preparation of the three-stage dispersion; preferably, the stirring and dispersion time is 0.4 to 0.6 hours. Alternatively, after adding the base material to the three dispersions, a shear dispersion treatment is performed first, followed by a stirring dispersion treatment; preferably, the shear dispersion treatment time is 0.4~0.6 h; preferably, the stirring dispersion treatment time is 2.5~3.5 h.

9. A field construction method for flange protection of gas-insulated metal-enclosed switchgear, characterized in that, This includes surface treatment and coating application; Surface treatment includes the following steps: The cylindrical area on the flange side and the substrate are mechanically polished, cleaned, and dried. Remove the peeling or flaking coating from the middle area of ​​the flange, clean and dry it, and then apply a release agent. The joint area of ​​the flange mating surface is protected by wrapping with sealing tape; The painting process includes the following steps: The gas-insulated metal-enclosed switchgear flange protection material according to any one of claims 1 to 6 is provided by compounding component A and component B. The mixed material is applied to the surface of the gas-insulated metal-enclosed switchgear flange after surface treatment. Preferably, the length of the polishing area for mechanical polishing is 50~200mm, and the surface roughness is Ra 15~80μm; Preferably, after mechanical polishing, the surface is first rinsed with water, then rinsed with alcohol with a purity of not less than 95%, and then cleaned with a hot air gun. Preferably, after removing the peeling or flaking coating from the middle area of ​​the flange, it is rinsed clean with water, purified water, and alcohol respectively, and then dried with a hot air gun. Preferably, the release agent is dimethyl silicone oil or paraffin wax; Preferably, after coating application, the final thickness of the coating is 0.5~5mm, and the air spraying parameters are pressure 0.3~0.7MPa and spraying flow rate 10~200ml / min.

10. A method for on-site testing of the curing degree of flange protective material, characterized in that, The degree of curing was tested by combining the "finger pressure method" and the "needle puncture method"; The "finger pressure method" is used to measure surface dryness, and the steps are as follows: (1) First, after the coating material is applied and cured, use the pad of your index finger to "lightly press and slide"; (2) If there is sticky substance on your fingers after lightly pressing and touching, it means that the coating has not been cured; otherwise, it has been "surface dry". (3) If the coating wrinkles and cracks after sliding, it means that the coating is not well cured inside; otherwise, the surface is dry. The "acupuncture method" is used to measure actual strength, and its steps are as follows: (1) After the surface drying time is set, the needle is slowly inserted in a direction perpendicular to the coating surface; (2) Pull out the needle that has been inserted into the coating. If the needle cannot be inserted normally or is difficult to insert and no adhesive material adheres when pulled out, it indicates that the coating has been cured well. Otherwise, it has not been fully cured.

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