Antifouling ceramic insulator and preparation method thereof

Abstract

The invention discloses an anti-fouling ceramic insulator and a preparation method thereof, the anti-fouling ceramic insulator is prepared by pretreating the surface of the ceramic insulator and drying at high temperature, and when composite gel, aluminum oxide and polyvinyl alcohol are mixed, pressed and roasted, a polyhedral oligomeric silsesquioxane structure in a modified filler in the composite gel is gradually decomposed and completely volatilized; in the decomposition process, a large amount of nanoscale holes and amorphous silicon dioxide which are converted from a rigid inorganic silica cage framework and are uniform in size and controllable in distribution are left in a ceramic matrix, cracks can be guided to be deflected, branched or bridged, and crack propagation energy is consumed, so that the fracture toughness of the ceramic is improved, the brittleness of the ceramic is improved, and the service life of the ceramic is prolonged. The magnesium chelate on the surface is beneficial to obtaining a denser sintered body and reducing internal pores, so that the mechanical strength and the electrical insulation performance of the ceramic are directly improved, and the modified polysiloxane molecules on the surface contain organic silicon segments and fluoroalkane structures, so that the insulator has a very good stain-resistant effect.

Description

Technical Field

[0001] This invention relates to the field of insulator manufacturing technology, specifically to a pollution-resistant ceramic insulator and its manufacturing method. Background Technology

[0002] Ceramic insulators, as crucial insulation components in power systems, play an indispensable role in overhead transmission lines and substations. Their primary functions are to support conductors and provide electrical insulation, while also withstanding mechanical loads and environmental factors. With the development of power systems towards ultra-high voltage, large capacity, and long-distance intelligent transmission, the performance requirements for ceramic insulators are increasingly stringent. Especially in complex and harsh environments, insulators face two major challenges: pollution flashover and mechanical failure, directly impacting the safe and stable operation of the power grid. Pollution flashover refers to the flashover phenomenon that occurs on the insulator surface due to the formation of a conductive layer of pollutants in a humid environment; while mechanical failure often manifests as the insulator breaking due to bending or torsional loads exceeding its bearing capacity. Therefore, researching advanced ceramic insulator technologies that combine anti-pollution and bending resistance is of great significance for ensuring the reliability of the power grid. Summary of the Invention

[0003] The purpose of this invention is to provide a pollution-resistant ceramic insulator and its preparation method, which solves the problems of poor pollution resistance and brittleness of current ceramic insulators.

[0004] The objective of this invention can be achieved through the following technical solutions: A method for preparing a pollution-resistant ceramic insulator specifically includes the following steps: Step A1: Mix the modified filler, citric acid, ethanol and deionized water evenly. Stir at 300-500 r / min and 40-50℃, add magnesium chloride hexahydrate, adjust the pH to 8-10, and react for 30-40 min. Then add tetrabutyl titanate, heat to 90-95℃, and react for 3-5 h to obtain the composite gel. Step A2: Weigh the following raw materials in parts by weight: 30-50 parts of composite gel, 70-90 parts of alumina and 5-10 parts of polyvinyl alcohol. Mix the raw materials evenly and press them into a mold. Under the condition of heating rate of 5℃ / min, heat to 1000℃ and hold for 30-40 min. Then, under the condition of heating rate of 2℃ / min, heat to 1500-1550℃ and hold for 2-3 h to obtain pretreated ceramic insulators.

[0005] Step A3: Mix octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide, tetramethyldisiloxane and DMF, and purge with nitrogen. React at 200-300 r / min and 90-95℃ for 3-5 h to obtain hydrogen-based polysiloxane. Mix hydrogen-based polysiloxane, γ-methacryloyloxypropyltrimethoxysilane, caster catalyst and DMF, and purge with nitrogen. React at 120-150 r / min and 80-85℃ for 6-8 h to obtain modified polysiloxane. Step A4: Weigh the following raw materials in parts by weight: 50-70 parts modified polysiloxane, 5-10 parts nano silica and 20-40 parts xylene. Mix the raw materials evenly to prepare a treatment solution. Spray the treatment solution onto the surface of the pretreated ceramic insulator and dry it at a temperature of 120-130℃ for 1-1.5 hours to obtain a pollution-resistant ceramic insulator.

[0006] Furthermore, the ratio of the modified filler, citric acid, ethanol, deionized water, magnesium chloride hexahydrate and tetrabutyl titanate in step A1 is 1g:5.8g:40mL:20mL:0.05g:10g.

[0007] Furthermore, in step A3, the molar ratio of octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide, and tetramethyldisiloxane is 1:0.2:1.5:1, the molar ratio of hydrogen-based polysiloxane and γ-methacryloyloxypropyltrimethoxysilane is 1:2, and the amount of caster catalyst used is 0.01 mol of the amount of γ-methacryloyloxypropyltrimethoxysilane.

[0008] Furthermore, the modified filler is prepared by the following steps: Step B1: Mix hexagonal boron nitride and sodium hydroxide solution, stir for 1-1.5 h at a speed of 600-800 r / min and a temperature of 20-25℃, then heat to 120-125℃ and reflux for 10-15 h, neutralize with hydrochloric acid, and wash with deionized water until neutral to obtain hydroxylated hexagonal boron nitride. Disperse the hydroxylated hexagonal boron nitride in ethanol, stir and add γ-methacryloyloxypropyltrimethoxysilane and deionized water at a speed of 150-200 r / min and a temperature of 60-70℃, and react for 3-5 h to obtain functionalized hexagonal boron nitride. Step B2: Mix phenyltrimethoxysilane, isopropanol, sodium hydroxide, and deionized water, and purge with nitrogen. React at 150-200 r / min and 85-90℃ for 3-5 hours. Then, cool to 20-25℃ and react for 10-15 hours to obtain sodium octaphenylcyclotetrasiloxane tetrasilanolate. Mix sodium octamethylcyclotetrasiloxane tetrasilanolate, triethylamine, and tetrahydrofuran, and purge with nitrogen. Stir and add methyldichlorosilane at 150-200 r / min and 0-5℃. React for 3-5 hours. Then, raise the temperature to 20-25℃ and continue the reaction for 18-20 hours to obtain dihydrocage-type silsesquioxane. Step B3: Functionalized hexagonal boron nitrogen, dihydro-cage silsesquioxane, caster catalyst and toluene are mixed, and nitrogen gas is introduced for protection. The mixture is reacted for 10-15 hours at a rotation speed of 200-300 r / min and a temperature of 80-85℃ to obtain a composite packing. The composite packing, mercaptosuccinic acid, benzophenone and toluene are mixed evenly and reacted for 3-5 hours at a rotation speed of 150-200 r / min, a temperature of 20-25℃ and 365nm ultraviolet light irradiation. The filtrate is filtered to remove the liquid, and the substrate is dried to obtain the modified packing.

[0009] Furthermore, in step B1, the ratio of hexagonal boron nitride to sodium hydroxide solution is 1g:100mL, the concentration of sodium hydroxide solution is 5mol / L, and the amount of γ-methacryloxypropyltrimethoxysilane is 3% of the mass of hydroxylated boron carbide.

[0010] Furthermore, in step B2, the ratio of phenyltrimethoxysilane, isopropanol, sodium hydroxide, and deionized water is 6 mmol:6 mL:4 mmol:7 mL, and the ratio of sodium tetrasiloxane tetrasiloxane, triethylamine, and methyldichlorosilane is 12 g:4.5 mL:3.5 g.

[0011] Furthermore, in step B3, the ratio of functionalized hexagonal boron nitrogen to dihydrocage-type silsesquioxane is 5:1, the amount of cassette catalyst is 0.01% of the mass of dihydrocage-type silsesquioxane, the molar ratio of mercapto and mercaptosuccinic acid on the composite filler is 1:1, and the amount of benzophenone is 0.3% of the mass of mercaptosuccinic acid.

[0012] The beneficial effects of the present invention are as follows: The anti-pollution ceramic insulator prepared by the present invention is obtained by spraying a treatment liquid onto the surface of the pretreated ceramic insulator and drying it at high temperature. The treatment liquid includes the following raw materials: modified polysiloxane, nano silica and xylene. The modified polysiloxane is obtained by ring-opening polymerization of octamethylcyclotetrasiloxane and trifluoropropylmethylcyclotrisiloxane as raw materials, and then end-capping with tetramethyldisiloxane to obtain hydrogen-based polysiloxane. The hydrogen-based polysiloxane is reacted with γ-methacryloyloxypropyltrimethoxysilane, so that the Si-H bond on the hydrogen-based polysiloxane reacts with the double bond on the γ-methacryloyloxypropyltrimethoxysilane to obtain the modified polysiloxane.

[0013] The pretreated ceramic insulator comprises the following raw materials: composite gel, alumina, and polyvinyl alcohol. The composite gel is prepared by reacting modified filler and citric acid with magnesium chloride hexahydrate to form a magnesium chelate on the surface of the modified filler. Tetrabutyl titanate is then added for hydrolysis and condensation to obtain the composite gel. The modified filler is prepared by treating hexagonal boron nitride with sodium hydroxide solution to obtain hydroxylated hexagonal boron nitride. The hydroxylated hexagonal boron nitride is then treated with γ-methacryloxypropyltrimethoxysilane to graft double bonds onto the surface, yielding functionalized hexagonal boron nitride. Phenylacetyltrimethoxysilane is hydrolyzed and condensed to obtain sodium octaphenylcyclotetrasiloxane tetrasilanolate. Sodium octaphenylcyclotetrasiloxane tetrasilanolate is reacted with methyldichlorosilane to form a magnesium chelate on the surface of the sodium octaphenylcyclotetrasiloxane tetrasilanolate. Sodium silanolate reacts with the Si-Cl bonds on methyldichlorosilane to prepare dihydro-cage-type silsesquioxane. The dihydro-cage-type silsesquioxane is then reacted with functionalized hexagonal boron nitride, causing the Si-H bonds on the dihydro-cage-type silsesquioxane to react with the double bonds on the functionalized hexagonal boron nitride, thus preparing a composite filler. The composite filler is then reacted with mercaptosuccinic acid under ultraviolet light irradiation, causing the double bonds on the composite filler to react with the mercapto groups on the mercaptosuccinic acid, thus preparing a modified filler.

[0014] During the calcination of composite gel, alumina, and polyvinyl alcohol in a mixed film, the cage-like silsesquioxane structure inside the modified filler in the composite gel gradually decomposes and completely volatilizes. This decomposition process leaves a large number of uniformly sized and controllably distributed nanoscale vacancies and amorphous silica in the ceramic matrix, which are transformed from rigid inorganic silica cage skeletons. These vacancies can guide crack deflection, branching, or bridging, and consume the energy for crack propagation, thereby improving the fracture toughness and brittleness of the ceramic. The magnesium chelate on the surface helps to obtain a denser sintered body and reduce internal porosity, thereby directly improving the mechanical strength and electrical insulation properties of the ceramic. The modified polysiloxane molecules on the surface contain organosilicon segments and fluoroalkane structures, which gives the insulator excellent anti-pollution effect. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Example 1: A method for preparing a pollution-resistant ceramic insulator, specifically including the following steps: Step A1: Mix the modified filler, citric acid, ethanol and deionized water evenly. Stir at 300 r / min and 40℃ and add magnesium chloride hexahydrate. Adjust the pH to 8 and react for 30 min. Then add tetrabutyl titanate, heat to 90℃ and react for 3 h to obtain the composite gel. Step A2: Weigh the following raw materials by weight: 30 parts composite gel, 70 parts alumina and 5 parts polyvinyl alcohol. Mix the raw materials evenly and press them into a mold. Under the condition of heating rate of 5℃ / min, heat to 1000℃ and hold for 30 min. Then, under the condition of heating rate of 2℃ / min, heat to 1500℃ and hold for 2 h to obtain pretreated ceramic insulators.

[0017] Step A3: Mix octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide, tetramethyldisiloxane and DMF, purge with nitrogen, and react for 3 h at 200 r / min and 90 °C to obtain hydrogen-based polysiloxane. Mix hydrogen-based polysiloxane, γ-methacryloyloxypropyltrimethoxysilane, caster catalyst and DMF, purge with nitrogen, and react for 6 h at 120 r / min and 80 °C to obtain modified polysiloxane. Step A4: Weigh the following raw materials in parts by weight: 50 parts modified polysiloxane, 5 parts nano silica and 20 parts xylene. Mix the raw materials evenly to prepare a treatment solution. Spray the treatment solution onto the surface of the pretreated ceramic insulator and dry it at 120°C for 1 hour to obtain a pollution-resistant ceramic insulator.

[0018] The ratio of the modified filler, citric acid, ethanol, deionized water, magnesium chloride hexahydrate and tetrabutyl titanate used in step A1 is 1g:5.8g:40mL:20mL:0.05g:10g.

[0019] The polyvinyl alcohol mentioned in step A2 has a molecular weight of 1000.

[0020] In step A3, the molar ratio of octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide, and tetramethyldisiloxane is 1:0.2:1.5:1, the molar ratio of hydrogen-based polysiloxane and γ-methacryloyloxypropyltrimethoxysilane is 1:2, and the amount of caster catalyst used is 0.01 mol of the amount of γ-methacryloyloxypropyltrimethoxysilane.

[0021] The modified filler is prepared by the following steps: Step B1: Mix hexagonal boron nitride and sodium hydroxide solution, stir for 1 hour at 600 r / min and 20℃, heat to 120℃ and reflux for 10 hours, neutralize with hydrochloric acid, and wash with deionized water until neutral to obtain hydroxylated hexagonal boron nitride. Disperse the hydroxylated hexagonal boron nitride in ethanol, stir at 150 r / min and 60℃, add γ-methacryloyloxypropyltrimethoxysilane and deionized water, and react for 3 hours to obtain functionalized hexagonal boron nitride. Step B2: Mix phenyltrimethoxysilane, isopropanol, sodium hydroxide and deionized water, purge with nitrogen, and react at 150 r / min and 85°C for 3 h. Then cool to 20°C and react for 10 h to obtain sodium octaphenylcyclotetrasiloxane tetrasilanolate. Mix sodium octamethylcyclotetrasiloxane tetrasilanolate, triethylamine and tetrahydrofuran, purge with nitrogen, and stir at 150 r / min and 0°C while adding methyldichlorosilane. React for 3 h, then heat to 20°C and continue reacting for 18 h to obtain dihydrocage-type silsesquioxane. Step B3: Functionalized hexagonal boron nitrogen, dihydro-cage silsesquioxane, caster catalyst and toluene are mixed, and nitrogen gas is introduced for protection. The mixture is reacted for 10 hours at a rotation speed of 200 r / min and a temperature of 80 °C to obtain a composite packing. The composite packing, mercaptosuccinic acid, benzophenone and toluene are mixed evenly and reacted for 3 hours at a rotation speed of 150 r / min, a temperature of 20 °C and irradiation with 365 nm ultraviolet light. The filtrate is removed by filtration and the substrate is dried to obtain the modified packing.

[0022] In step B1, the ratio of hexagonal boron nitride to sodium hydroxide solution is 1g:100mL, the concentration of sodium hydroxide solution is 5mol / L, and the amount of γ-methacryloyloxypropyltrimethoxysilane is 3% of the mass of hydroxylated boron carbide.

[0023] The ratio of phenyltrimethoxysilane, isopropanol, sodium hydroxide and deionized water in step B2 is 6 mmol:6 mL:4 mmol:7 mL, sodium octamethylcyclotetrasiloxane tetrasilanolate, triethylamine and methyldichlorosilane is 12 g:4.5 mL:3.5 g.

[0024] In step B3, the ratio of functionalized hexagonal nitrogen boron to dihydro-cage silsesquioxane is 5:1, the amount of cassette catalyst is 0.01% of the mass of dihydro-cage silsesquioxane, the molar ratio of mercapto and mercaptosuccinic acid on the composite filler is 1:1, and the amount of benzophenone is 0.3% of the mass of mercaptosuccinic acid.

[0025] Example 2: A method for preparing a pollution-resistant ceramic insulator, specifically including the following steps: Step A1: Mix the modified filler, citric acid, ethanol and deionized water evenly. Stir at 300 r / min and 45℃ and add magnesium chloride hexahydrate. Adjust the pH to 10 and react for 35 min. Then add tetrabutyl titanate, heat to 95℃ and react for 4 h to obtain the composite gel. Step A2: Weigh the following raw materials by weight: 40 parts composite gel, 80 parts alumina and 7.5 parts polyvinyl alcohol. Mix the raw materials evenly and press them into a mold. Under the condition of heating rate of 5℃ / min, heat to 1000℃ and hold for 35min. Then, under the condition of heating rate of 2℃ / min, heat to 1530℃ and hold for 3h to obtain pretreated ceramic insulators.

[0026] Step A3: Octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide, tetramethyldisiloxane and DMF are mixed, and under nitrogen protection, the mixture is reacted for 4 hours at a speed of 200 r / min and a temperature of 95 °C to obtain hydrogen-based polysiloxane. Hydrogen-based polysiloxane, γ-methacryloyloxypropyltrimethoxysilane, caster catalyst and DMF are mixed, and under nitrogen protection, the mixture is reacted for 7 hours at a speed of 120 r / min and a temperature of 85 °C to obtain modified polysiloxane. Step A4: Weigh the following raw materials in parts by weight: 60 parts modified polysiloxane, 7.5 parts nano silica and 30 parts xylene. Mix the raw materials evenly to prepare a treatment solution. Spray the treatment solution onto the surface of the pretreated ceramic insulator and dry it at 125°C for 1.5 hours to obtain a pollution-resistant ceramic insulator.

[0027] The ratio of the modified filler, citric acid, ethanol, deionized water, magnesium chloride hexahydrate and tetrabutyl titanate used in step A1 is 1g:5.8g:40mL:20mL:0.05g:10g.

[0028] The polyvinyl alcohol mentioned in step A2 has a molecular weight of 1000.

[0029] In step A3, the molar ratio of octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide, and tetramethyldisiloxane is 1:0.2:1.5:1, the molar ratio of hydrogen-based polysiloxane and γ-methacryloyloxypropyltrimethoxysilane is 1:2, and the amount of caster catalyst used is 0.01 mol of the amount of γ-methacryloyloxypropyltrimethoxysilane.

[0030] The modified filler is prepared by the following steps: Step B1: Mix hexagonal boron nitride and sodium hydroxide solution, stir for 1.5 h at 800 r / min and 20 °C, heat to 120 °C and reflux for 13 h, neutralize with hydrochloric acid, and wash with deionized water until neutral to obtain hydroxylated hexagonal boron nitride. Disperse the hydroxylated hexagonal boron nitride in ethanol, stir at 150 r / min and 65 °C, add γ-methacryloyloxypropyltrimethoxysilane and deionized water, and react for 4 h to obtain functionalized hexagonal boron nitride. Step B2: Phenylacetoxysilane, isopropanol, sodium hydroxide and deionized water were mixed and purged with nitrogen. The mixture was reacted at 150 r / min and 90 °C for 4 h. The temperature was then lowered to 20 °C and the reaction was continued for 15 h to obtain sodium octaphenylcyclotetrasiloxane tetrasilanolate. Sodium octamethylcyclotetrasiloxane tetrasilanolate, triethylamine and tetrahydrofuran were mixed and purged with nitrogen. The mixture was stirred and methyldichlorosilane was added at 150 r / min and 5 °C. The mixture was reacted for 4 h. The temperature was then raised to 20 °C and the reaction was continued for 20 h to obtain dihydrocage-type silsesquioxane. Step B3: Functionalized hexagonal boron nitrogen, dihydro-cage silsesquioxane, caster catalyst and toluene are mixed, and nitrogen gas is introduced for protection. The mixture is reacted for 13 hours at a rotation speed of 200 r / min and a temperature of 80 °C to obtain a composite packing. The composite packing, mercaptosuccinic acid, benzophenone and toluene are mixed evenly and reacted for 4 hours at a rotation speed of 150 r / min, a temperature of 25 °C and 365 nm ultraviolet light irradiation. The filtrate is removed by filtration and the substrate is dried to obtain the modified packing.

[0031] In step B1, the ratio of hexagonal boron nitride to sodium hydroxide solution is 1g:100mL, the concentration of sodium hydroxide solution is 5mol / L, and the amount of γ-methacryloyloxypropyltrimethoxysilane is 3% of the mass of hydroxylated boron carbide.

[0032] The ratio of phenyltrimethoxysilane, isopropanol, sodium hydroxide and deionized water in step B2 is 6 mmol:6 mL:4 mmol:7 mL, sodium octamethylcyclotetrasiloxane tetrasilanolate, triethylamine and methyldichlorosilane is 12 g:4.5 mL:3.5 g.

[0033] In step B3, the ratio of functionalized hexagonal nitrogen boron to dihydro-cage silsesquioxane is 5:1, the amount of cassette catalyst is 0.01% of the mass of dihydro-cage silsesquioxane, the molar ratio of mercapto and mercaptosuccinic acid on the composite filler is 1:1, and the amount of benzophenone is 0.3% of the mass of mercaptosuccinic acid.

[0034] Example 3: A method for preparing a pollution-resistant ceramic insulator, specifically including the following steps: Step A1: Mix the modified filler, citric acid, ethanol and deionized water evenly. Stir at 500 r / min and 50℃ and add magnesium chloride hexahydrate. Adjust the pH to 10 and react for 40 min. Then add tetrabutyl titanate, heat to 95℃ and react for 5 h to obtain the composite gel. Step A2: Weigh the following raw materials by weight: 50 parts composite gel, 90 parts alumina and 10 parts polyvinyl alcohol. Mix the raw materials evenly and press them into a mold. Under the condition of heating rate of 5℃ / min, heat to 1000℃ and hold for 40 min. Then, under the condition of heating rate of 2℃ / min, heat to 1550℃ and hold for 3 h to obtain pretreated ceramic insulators.

[0035] Step A3: Mix octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide, tetramethyldisiloxane and DMF, purge with nitrogen, and react for 5 h at 300 r / min and 95 °C to obtain hydrogen-based polysiloxane. Mix hydrogen-based polysiloxane, γ-methacryloyloxypropyltrimethoxysilane, caster catalyst and DMF, purge with nitrogen, and react for 8 h at 150 r / min and 85 °C to obtain modified polysiloxane. Step A4: Weigh the following raw materials in parts by weight: 70 parts modified polysiloxane, 10 parts nano silica and 40 parts xylene. Mix the raw materials evenly to prepare a treatment solution. Spray the treatment solution onto the surface of the pretreated ceramic insulator and dry it at 130°C for 1.5 hours to obtain a pollution-resistant ceramic insulator.

[0036] The ratio of the modified filler, citric acid, ethanol, deionized water, magnesium chloride hexahydrate and tetrabutyl titanate used in step A1 is 1g:5.8g:40mL:20mL:0.05g:10g.

[0037] The polyvinyl alcohol mentioned in step A2 has a molecular weight of 1000.

[0038] In step A3, the molar ratio of octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide, and tetramethyldisiloxane is 1:0.2:1.5:1, the molar ratio of hydrogen-based polysiloxane and γ-methacryloyloxypropyltrimethoxysilane is 1:2, and the amount of caster catalyst used is 0.01 mol of the amount of γ-methacryloyloxypropyltrimethoxysilane.

[0039] The modified filler is prepared by the following steps: Step B1: Mix hexagonal boron nitride and sodium hydroxide solution, stir for 1.5 h at 800 r / min and 25 °C, heat to 125 °C and reflux for 15 h, neutralize with hydrochloric acid, and wash with deionized water until neutral to obtain hydroxylated hexagonal boron nitride. Disperse the hydroxylated hexagonal boron nitride in ethanol, stir at 200 r / min and 70 °C, add γ-methacryloyloxypropyltrimethoxysilane and deionized water, and react for 5 h to obtain functionalized hexagonal boron nitride. Step B2: Phenylacetoxysilane, isopropanol, sodium hydroxide and deionized water were mixed and purged with nitrogen. The mixture was reacted at 200 r / min and 90 °C for 5 h. The temperature was then lowered to 25 °C and the reaction was continued for 15 h to obtain sodium octaphenylcyclotetrasiloxane tetrasilanolate. Sodium octamethylcyclotetrasiloxane tetrasilanolate, triethylamine and tetrahydrofuran were mixed and purged with nitrogen. The mixture was stirred and methyldichlorosilane was added at 200 r / min and 5 °C. The mixture was reacted for 5 h. The temperature was then raised to 25 °C and the reaction was continued for 20 h to obtain dihydrocage-type silsesquioxane. Step B3: Functionalized hexagonal boron nitrogen, dihydro-cage silsesquioxane, caster catalyst and toluene are mixed, and nitrogen gas is introduced for protection. The mixture is reacted for 15 hours at a speed of 300 r / min and a temperature of 85 °C to obtain a composite packing. The composite packing, mercaptosuccinic acid, benzophenone and toluene are mixed evenly and reacted for 5 hours at a speed of 200 r / min, a temperature of 25 °C and 365 nm ultraviolet light irradiation. The filtrate is removed by filtration and the substrate is dried to obtain the modified packing.

[0040] In step B1, the ratio of hexagonal boron nitride to sodium hydroxide solution is 1g:100mL, the concentration of sodium hydroxide solution is 5mol / L, and the amount of γ-methacryloyloxypropyltrimethoxysilane is 3% of the mass of hydroxylated boron carbide.

[0041] The ratio of phenyltrimethoxysilane, isopropanol, sodium hydroxide and deionized water in step B2 is 6 mmol:6 mL:4 mmol:7 mL, sodium octamethylcyclotetrasiloxane tetrasilanolate, triethylamine and methyldichlorosilane is 12 g:4.5 mL:3.5 g.

[0042] In step B3, the ratio of functionalized hexagonal nitrogen boron to dihydro-cage silsesquioxane is 5:1, the amount of cassette catalyst is 0.01% of the mass of dihydro-cage silsesquioxane, the molar ratio of mercapto and mercaptosuccinic acid on the composite filler is 1:1, and the amount of benzophenone is 0.3% of the mass of mercaptosuccinic acid.

[0043] Comparative Example 1: This comparative example did not include magnesium chloride hexahydrate compared to Example 1, but the remaining steps were the same.

[0044] Comparative Example 2: This comparative example did not include dihydro-cage-type silsesquioxane compared to Example 1, but the remaining steps were the same.

[0045] Comparative Example 3: This comparative example did not include trifluoropropylmethylcyclotrisiloxane compared to Example 1, but the remaining steps were the same.

[0046] The insulators prepared in Examples 1-3 and Comparative Examples 1-3 were tested for their anti-pollution level according to the test method of GB / T3810.14-2016. The composite gel, alumina and polyvinyl alcohol raw materials prepared in Examples 1-3 and Comparative Examples 1-3 were mixed evenly and pressed into a film to form a sample with a size of 160mm×20mm×10mm. A three-point bending test was performed using a digital display flexural strength tester. The test results are shown in Table 1.

[0047] Table 1 Example 1 Example 3 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 antifouling level Level 5 Level 5 Level 5 Level 5 Level 5 Level 4 Flexural strength (MPa) 402.36 415.84 423.51 382.48 347.79 401.14 As shown in Table 1, this application has excellent stain resistance and good bending resistance.

[0048] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method of making a pollution resistant ceramic insulator, characterized by: Specifically comprising the following steps: Step A1: the modified filler, citric acid, ethanol and deionized water are mixed and stirred, and magnesium chloride hexahydrate is added, the pH is adjusted to be alkaline, the reaction is carried out, tetrabutyl titanate is added, and the reaction is carried out by heating, to obtain a composite gel; Step A2: the following raw materials are weighed: 30-50 parts of the composite gel, 70-90 parts of alumina and 5-10 parts of polyvinyl alcohol, the raw materials are mixed uniformly and pressed into a mold, and the pretreated ceramic insulator is prepared by heat preservation treatment; Step A3: octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide, tetramethyldisiloxane and DMF are mixed, nitrogen is introduced for protection, and the reaction is carried out to obtain a hydrogen-containing polysiloxane; the hydrogen-containing polysiloxane, γ-methacryloyloxypropyltrimethoxysilane, Karstedt catalyst and DMF are mixed, nitrogen is introduced for protection, and the reaction is carried out to obtain a modified polysiloxane; Step A4: the following raw materials are weighed: 50-70 parts of the modified polysiloxane, 5-10 parts of nano silicon dioxide and 20-40 parts of dimethylbenzene, the raw materials are mixed uniformly to obtain a treatment liquid, the treatment liquid is sprayed on the surface of the pretreated ceramic insulator, and drying treatment is carried out to obtain the anti-fouling ceramic insulator.

2. The method for preparing the anti-pollution ceramic insulator according to claim 1, characterized in that: The amount ratio of the modified filler, citric acid, ethanol, deionized water, magnesium chloride hexahydrate and tetrabutyl titanate in step A1 is 1g:5.8g:40mL:20mL:0.05g:10g.

3. The method for preparing the anti-pollution ceramic insulator according to claim 1, characterized in that: The molar ratio of octamethylcyclotetrasiloxane, trifluoropropylmethylcyclotrisiloxane, tetramethylammonium hydroxide and tetramethyldisiloxane in step A3 is 1:0.2:1.5:1, and the molar ratio of the hydrogen-containing polysiloxane and γ-methacryloyloxypropyltrimethoxysilane is 1:

2.

4. The method for preparing the anti-pollution ceramic insulator according to claim 1, characterized in that: The modified filler is prepared by the following steps: Step B1: hexagonal boron nitride and sodium hydroxide solution are mixed and stirred, then heated to reflux, neutralized with hydrochloric acid, and washed with deionized water until neutral to obtain hydroxylated hexagonal boron nitride; the hydroxylated hexagonal boron nitride is dispersed in ethanol, stirred, and γ-methacryloyloxypropyltrimethoxysilane and deionized water are added to carry out the reaction to obtain functionalized hexagonal boron nitride; Step B2: phenyltrimethoxysilane, isopropyl alcohol, sodium hydroxide and deionized water are mixed, nitrogen is introduced for protection, and the reaction is carried out to obtain octaphenylcyclotetrasiloxane sodium silanol; octaphenylcyclotetrasiloxane sodium silanol, triethylamine and tetrahydrofuran are mixed, nitrogen is introduced for protection, stirred, and methyl dichlorosilane is added to carry out the reaction to obtain dihydrogen cage-type silsesquioxane; Step B3: the functionalized hexagonal boron, dihydrogen cage-type silsesquioxane, Karstedt catalyst and toluene are mixed, nitrogen is introduced for protection, and the reaction is carried out to obtain a composite filler; the composite filler, mercaptobutanoic acid, benzophenone and toluene are mixed uniformly, ultraviolet light is irradiated for reaction, the filtrate is removed by filtration, and the substrate is dried to obtain the modified filler.

5. The method of claim 4, wherein the ceramic insulator is a pollution-resistant ceramic insulator. The amount ratio of hexagonal boron nitride and sodium hydroxide solution in step B1 is 1g:100mL, and the amount of γ-methacryloyloxypropyltrimethoxysilane is 3% of the mass of the hydroxylated boron carbide.

6. The method of claim 4, wherein the ceramic insulator is a pollution-resistant ceramic insulator. The use amount ratio of phenyl trimethoxysilane, isopropanol, sodium hydroxide and deionized water in step B2 is 6mmol:6mL:4mmol:7mL, and the use amount ratio of sodium tetraethyl orthosilicate, triethylamine and methyl dichlorosilane is 12g:4.5mL:3.5g.

7. The method of claim 4, wherein the ceramic insulator is a pollution-resistant ceramic insulator. The use amount ratio of functionalized hexagonal boron nitride and dihydrogen-based cage-type silsesquioxane in step B3 is 5:1, and the molar ratio of mercapto groups on the composite filler and mercaptosuccinic acid is 1:

1.

8. An anti-fouling ceramic insulator, characterized by: Prepared according to the preparation method in any one of claims 1-7.