Glaze for improving the bonding strength of glaze blanks and method for glazing porcelain insulators

Abstract

The present application relates to porcelain insulator technical field, specifically to the glaze for improving the bonding strength of biscuit and the glazing method of porcelain insulator, which is composed of the following components by weight: low-carbon base glaze 75-85 parts, flaky talcum powder-mica co-adjusting agent 8-12 parts, carbon nanotube additive 1.5-3 parts, low-carbon fluxing agent 3-5 parts, self-cleaning modifier 1-2 parts. The present application adds the flaky talcum powder-mica co-adjusting agent and carbon nanotube additive prepared by refining, and the two have synergistic effect. The flaky talcum powder-mica co-adjusting agent can fill the interface gap of glaze biscuit, improve the flowability of glaze, reduce the shrinkage and cracking.

Description

Technical Field

[0001] This invention relates to the field of porcelain insulator technology, specifically to glazes for improving the bonding strength between the glaze body and the porcelain insulator, and methods for glazing porcelain insulators. Background Technology

[0002] Porcelain insulators are indispensable key components in power transmission systems, and their performance directly affects the safety and stability of power transmission. The glaze layer, as the surface protective layer of porcelain insulators, not only improves the insulator's insulation performance and corrosion resistance but also enhances its surface smoothness and reduces contaminant adhesion. However, existing porcelain insulator glazes generally suffer from two major problems: first, insufficient bonding strength between the glaze and the blank, leading to defects such as glaze peeling and cracking during transportation, installation, and long-term service, resulting in decreased insulation performance and even power safety accidents; second, traditional glaze production and firing processes are energy-intensive and produce large carbon emissions, which does not meet the current "dual-carbon" strategic development needs, and the glaze layer has poor self-cleaning properties, easily accumulating dust, oil, and other contaminants on the surface, requiring regular manual cleaning and increasing maintenance costs.

[0003] To address the aforementioned issues, existing technologies often improve the bonding performance of the glaze and body by adding a single modifier, such as talc or mica powder. However, their modulating effect is limited, making it difficult to significantly improve the bonding strength of the glaze and body. Meanwhile, although carbon nanotubes, as high-performance additives, are used in ceramic materials to enhance mechanical properties, their poor dispersibility and tendency to agglomerate prevent them from fully realizing their role in the glaze. Furthermore, existing technologies do not specify the specific modification and preparation process of carbon nanotubes, nor do they synergistically use them with flake talc-mica co-modifiers, making it impossible to simultaneously optimize the bonding strength, low-carbon performance, and self-cleaning properties of the glaze and body.

[0004] Furthermore, the optimization of the self-cleaning properties of existing glazes largely relies on high-cost nanomaterials, resulting in high production costs and difficulty in meeting low-carbon requirements. Additionally, the lack of systematic performance data and comparative analyses makes it impossible to clearly define the mechanisms of action and importance of each additive. Therefore, developing a low-carbon, environmentally friendly glaze with high glaze-body bonding strength, excellent self-cleaning properties, and a clearly defined additive preparation process, along with a corresponding glazing method, has become a pressing technical challenge in the field of ceramic insulators. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the purpose of this invention is to provide a glaze material and a glazing method for porcelain insulators that improve the bonding strength of the glaze body, so as to solve the problems mentioned in the background art.

[0006] The present invention solves the technical problem by adopting the following technical solution: This invention provides a glaze that improves the bonding strength between the glaze body and the glaze. The glaze is composed of the following components in parts by weight: 75-85 parts of low-carbon base glaze, 8-12 parts of flake talc-mica co-modifier, 1.5-3 parts of carbon nanotube additive, 3-5 parts of low-carbon flux, and 1-2 parts of self-cleaning modifier. The low-carbon base glaze uses industrial waste residue as the main raw material and is composed of the following components in parts by weight: 25-35 parts fly ash, 15-25 parts coal gangue, 10-18 parts kaolin, 8-15 parts quartz sand, and 5-10 parts limestone. The utilization rate of the industrial waste residue is ≥60%, which can significantly reduce the energy consumption and carbon emissions of raw material mining in the glaze production process, and achieve low-carbon and environmentally friendly production. The low-carbon flux is a compound of borax and feldspar in a weight ratio of 1:2-3. Its melting point is lower than that of traditional fluxes, which can reduce the firing temperature of the glaze and further reduce energy consumption and carbon emissions during the firing process. The self-cleaning modifier is a compound of nano-titanium dioxide and sodium fluorosilicate in a weight ratio of 3:1-2. Nano-titanium dioxide can decompose surface contaminants through photocatalysis, while sodium fluorosilicate can reduce the surface tension of the glaze and improve its hydrophobic self-cleaning performance. The two work together to optimize the self-cleaning effect of the glaze. Both the flake talc-mica co-modifier and the carbon nanotube additive were prepared through fine processing, and the specific preparation methods are as follows: 1. Preparation method of flaky talc-mica co-modifier Step 1: Raw material pretreatment: Select natural talc ore and mica ore, crush them and pass them through a 200-mesh sieve to remove impurities, and obtain coarse talc powder and coarse mica powder; place the coarse talc powder and coarse mica powder in a vacuum drying oven and dry them at 80℃ for 2 hours to remove moisture, and set them aside for later use. Step 2: Flake Formation: Mix the pretreated coarse talc powder and coarse mica powder at a weight ratio of 3:1-2, add them to a high-speed mixer, add 0.8-1.2% of the total weight of the mixed powder with silane coupling agent KH-570, set the temperature to 60℃, and mix at high speed for 30 minutes to ensure that the coupling agent is evenly coated on the powder surface; then send the mixed powder into an air jet mill, adjust the airflow speed to 20-25m / s, and pulverize for 30-40 minutes to obtain a flake mixed powder, wherein the aspect ratio of the flake particles is 15-25:1 and the particle size is 10-20μm; Step 3: Modification treatment: Add the flake-shaped mixed powder to deionized water to prepare a suspension with a mass concentration of 15-20%, and ultrasonically disperse for 30 minutes to ensure uniform dispersion of the flake-shaped particles; then add 2-3% of the total weight of polyvinylpyrrolidone to the suspension and stir in a 60℃ water bath for 2 hours to perform surface modification, improve its dispersibility in the glaze and its compatibility with the base glaze; Step 4: Drying and Shaping: Vacuum filter the modified suspension to obtain a filter cake; place the filter cake in a vacuum drying oven and dry it at 105℃ for 4-6 hours. After pulverizing, pass it through a 300-mesh sieve to obtain a flake-shaped talc-mica co-modifier for later use; this co-modifier, through the synergistic effect of its flake structure, can fill the gaps between the glaze layer and the body, improve the fluidity of the glaze, enhance the bonding strength between the glaze and the body, and at the same time reduce the shrinkage rate of the glaze and reduce the risk of cracking.

[0007] 2. Preparation method of carbon nanotube additives Step 1: Purification of carbon nanotubes: Select multi-walled carbon nanotubes and add them to concentrated nitric acid at a solid-liquid ratio of 1g:100ml. Reflux at 120℃ for 1.5h, cool to room temperature, and filter to obtain a filter cake. Wash the filter cake twice with a 5% sodium hydroxide solution, then wash with deionized water until neutral, and dry at 80℃ for 10h to remove impurities and amorphous carbon from the surface of the carbon nanotubes, thus obtaining purified carbon nanotubes. Step 2: Non-covalent modification: Purified carbon nanotubes and polyvinylpyrrolidone were added to deionized water at a mass ratio of 1g:30mg, ultrasonically dispersed for 18h, filtered through a 0.2μm porous membrane, washed, and dried at 80℃ for 8h to obtain non-covalent modified carbon nanotubes, which improves the dispersibility of carbon nanotubes and avoids aggregation. Step 3: Coating and Modification: Non-covalently modified carbon nanotubes were added to an 8-12 wt% isopropanol solution, ultrasonically dispersed for 25 min, and the pH was adjusted to 2.2. Then, tetrabutyl titanate was added, with a ratio of non-covalently modified carbon nanotubes to tetrabutyl titanate of 1 g: 85 ml. The mixture was stirred at room temperature for 3 h and filtered to obtain a filter cake. The filter cake was washed three times alternately with anhydrous ethanol and deionized water, dried at 100 °C for 2.5 h, and then sintered in a vacuum at a heating rate of 8 °C / min to 460 °C for 4 h to obtain titanium dioxide / non-covalently modified carbon nanotubes. Step 4: Secondary Coating: Tetraethyl orthosilicate and anhydrous ethanol are mixed at a volume ratio of 1:1 and stirred at 60℃ for 3 hours to obtain solution A; titanium dioxide / non-covalently modified carbon nanotubes, polyvinylpyrrolidone, and deionized water are mixed at a mass ratio of 1g:21mg:100ml and stirred at room temperature for 20 minutes. Solution A is added, with the ratio of tetraethyl orthosilicate to titanium dioxide / non-covalently modified carbon nanotubes being 76ml:1g. The mixture is stirred at 40℃ for 2 hours, centrifuged, and the liquid is separated to obtain a filter cake; the filter cake is washed three times alternately with anhydrous ethanol and deionized water, dried at 52℃ for 2 hours, and finally sintered under vacuum at 370℃ for 3 hours to obtain a carbon nanotube additive for later use; this additive, through the double coating of titanium dioxide and silicon dioxide, not only solves the problem of carbon nanotube agglomeration but also works synergistically with the self-cleaning modifier to improve the self-cleaning performance of the glaze layer. At the same time, its three-dimensional network structure can bridge microcracks in the glaze layer, significantly improving the bonding strength and toughness of the glaze body.

[0008] The above-mentioned glaze preparation method Includes the following steps: S1: Weigh each component of the low-carbon base glaze according to the weight proportions, add it to a ball mill, add 30-40% of the total weight of the components of deionized water, and ball mill for 3-4 hours at a speed of 300-350 r / min to obtain the base glaze slurry. Zirconia ceramic grinding balls are used during the ball milling process, and the weight ratio of material, balls and water is 1:2:1 to ensure uniform fineness of the glaze slurry. S2: Add flake talc-mica co-modifier, carbon nanotube additive, low-carbon flux and self-cleaning modifier to the base glaze slurry, and continue ball milling for 1-1.5 hours to ensure uniform dispersion of each component and obtain a mixed glaze slurry; S3: Let the mixed glaze slurry stand for 20-30 minutes to remove air bubbles, and then pass it through a 300-mesh sieve to obtain the finished glaze. This preparation process does not require high-temperature firing pretreatment, has low energy consumption, and uses industrial waste residue to replace some traditional raw materials. Carbon emissions are reduced by more than 30% compared with traditional glazes, which meets the requirements of low-carbon technology.

[0009] A method for glazing porcelain insulators Using the above-mentioned glaze, the following steps are included: Step 1: Pre-treatment of porcelain insulator blanks: Select the formed porcelain insulator blanks, place them in a drying oven, and dry them at 120℃ for 4-6 hours to remove the internal moisture of the blanks; then use diamond to sandblast the surface of the blanks to increase the surface roughness of the blanks and improve the adhesion between the glaze and the blanks. After treatment, clean the surface of the blanks with anhydrous ethanol and let them dry for later use. Step 2: Glazing: High-pressure electrostatic glazing is used to evenly spray the glaze onto the surface of the pretreated porcelain insulator blank. The glazing pressure is 0.3-0.5MPa, the glazing distance is 20-30cm, the glazing speed is 5-8cm / s, and the glaze thickness is controlled to be 0.25-0.35mm. A stepped drying method is used during the glazing process to avoid glaze cracking and improve glaze uniformity. Step 3: Drying treatment: Place the glazed porcelain insulator blank in a constant temperature drying oven, first dry at 60℃ for 2 hours, then raise the temperature to 100℃ and dry for 3-4 hours to ensure that the glaze layer is completely dry and there is no moisture residue. Step 4: Firing Treatment: The dried porcelain insulator blanks are sent into an intelligent kiln and fired in stages, as detailed below: ① Low-temperature preheating stage: The temperature is increased from room temperature to 400℃ at a rate of 5℃ / min and held for 1 hour to remove residual moisture and organic matter from the glaze and body. ② Medium-temperature heating stage: The temperature is increased from 400℃ to 800℃ at a rate of 3℃ / min, and held for 0.5h to promote the initial reaction of the glaze components; ③ High-temperature firing stage: The temperature is increased from 800℃ to 1150-1200℃ at a rate of 2℃ / min, and held for 2-3 hours to allow the glaze to fully melt, flow, and bond tightly with the body. This firing temperature is 100-150℃ lower than the traditional glaze firing temperature, which significantly reduces energy consumption and carbon emissions. ④ Cooling stage: Cool down from the firing temperature to room temperature at a rate of 4℃ / min to avoid cracking of the glaze layer due to excessive cooling. Step 5: Post-processing: Remove the fired porcelain insulators, remove surface impurities, and after passing the inspection, obtain the finished porcelain insulators.

[0010] Compared with the prior art, the present invention has the following beneficial effects: This invention's glaze uses industrial waste (fly ash, coal gangue) as the main raw material, with a utilization rate of ≥60%, replacing a large amount of traditional mineral raw materials and reducing environmental damage caused by raw material mining. Simultaneously, it employs low-melting-point flux and a low-temperature firing process, reducing the firing temperature by 100-150℃. Carbon emissions during glaze production and firing are reduced by more than 30% compared to traditional glazes, and energy consumption is reduced by 25-30%, fully aligning with the development direction of low-carbon technology. The glaze-body bonding strength is high: by adding finely prepared flake talc-mica co-modifier and carbon nanotube additives, the two work synergistically. The flake talc-mica co-modifier fills the voids at the glaze-body interface, improving glaze fluidity, reducing shrinkage, and minimizing cracking. The carbon nanotube additives form a three-dimensional network structure, bridging microcracks, hindering crack propagation, and significantly improving the glaze-body bonding strength. Testing shows that the glaze-body bonding strength is ≥28MPa, significantly higher than... The self-cleaning performance is improved by more than 40% compared to traditional glazes, avoiding defects such as glaze peeling and cracking. It boasts excellent self-cleaning properties: through the synergistic effect of self-cleaning modifiers and carbon nanotube additives, the photocatalytic effect of nano-titanium dioxide decomposes surface contaminants. Sodium fluorosilicate reduces the surface tension of the glaze layer, improving hydrophobicity. Simultaneously, the titanium dioxide coating on the surface of the carbon nanotube additives further enhances the photocatalytic effect. Testing shows that the glaze layer water contact angle is ≥115°, the amount of dirt adhering is ≤0.8g / m², and the self-cleaning rate is ≥92%, effectively reducing contaminant adhesion and lowering maintenance costs. The additive preparation process is refined: the specific preparation steps for the flake talc-mica co-modifier and carbon nanotube additives are clearly defined, including pretreatment, flake formation, modification, and coating processes. This solves the problems of poor dispersibility and insufficient effect of traditional additives, ensuring uniform dispersion of the additives in the glaze and fully leveraging their synergistic enhancement and self-cleaning effects. Detailed Implementation

[0011] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. 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.

[0012] Example 1 Glaze formula (parts by weight) 80 parts of low-carbon base glaze (30 parts fly ash, 20 parts coal gangue, 15 parts kaolin, 10 parts quartz sand, 5 parts limestone), 10 parts of flake talc-mica co-modifier, 2 parts of carbon nanotube additive, 4 parts of low-carbon flux (1.3 parts borax, 2.7 parts feldspar), and 1.5 parts of self-cleaning modifier (1 part nano titanium dioxide, 0.5 parts sodium fluorosilicate).

[0013] Preparation of flake talc-mica co-modifier Step 1: Raw material pretreatment: Select natural talc ore and mica ore, crush them and pass them through a 200-mesh sieve to remove impurities, and obtain coarse talc powder and coarse mica powder; place them in a vacuum drying oven and dry them at 80℃ for 2 hours for later use. Step 2: Flake Formation: Mix coarse talc powder and coarse mica powder at a weight ratio of 3:1.5, add to a high-speed mixer, add 1.0% of the total weight of the mixed powder with silane coupling agent KH-570, mix at high speed at 60℃ for 30 min, then send to an air jet mill, adjust the airflow speed to 22 m / s, and pulverize for 35 min to obtain flake mixed powder (aspect ratio 20:1, particle size 15 μm). Step 3: Modification treatment: Add the flake mixed powder to deionized water to prepare a suspension with a mass concentration of 18%, ultrasonically disperse for 30 min, add 2.5% polyvinylpyrrolidone of the total weight of the suspension, and stir in a water bath at 60℃ for 2 h. Step 4: Drying and shaping: Vacuum filtration is used to obtain filter cake, which is then vacuum dried at 105℃ for 5 hours. After pulverization, the cake is passed through a 300-mesh sieve to obtain flaky talc-mica co-modifier.

[0014] Preparation of carbon nanotube additives Step 1: Purification of carbon nanotubes: Select multi-walled carbon nanotubes, add concentrated nitric acid (solid-liquid ratio 1g:100ml), reflux at 120℃ for 1.5h, cool and filter, wash the filter cake twice with 5% sodium hydroxide solution, then wash with deionized water until neutral, and dry at 80℃ for 10h to obtain purified carbon nanotubes. Step 2: Non-covalent modification: Purified carbon nanotubes and polyvinylpyrrolidone were added to deionized water at a ratio of 1g:30mg, ultrasonically dispersed for 18h, filtered through a 0.2μm porous membrane, washed, and dried at 80℃ for 8h to obtain non-covalently modified carbon nanotubes. Step 3: Coating and Modification: Non-covalently modified carbon nanotubes were added to a 10wt% isopropanol solution, ultrasonically dispersed for 25 min, the pH was adjusted to 2.2, tetrabutyl titanate (1g:85ml ratio) was added, and the mixture was stirred at room temperature for 3 h. The mixture was then filtered to obtain a filter cake. The filter cake was washed three times alternately with anhydrous ethanol and deionized water, dried at 100℃ for 2.5 h, and heated to 460℃ under vacuum at a rate of 8℃ / min, and held for 4 h to obtain titanium dioxide / non-covalently modified carbon nanotubes. Step 4: Secondary coating: Tetraethyl orthosilicate and anhydrous ethanol are mixed at a ratio of 1:1 and stirred at 60°C for 3 hours to obtain solution A; titanium dioxide / non-covalently modified carbon nanotubes, polyvinylpyrrolidone and deionized water are mixed at a ratio of 1g:21mg:100ml and stirred at room temperature for 20 minutes, solution A is added (the ratio of tetraethyl orthosilicate to titanium dioxide / non-covalently modified carbon nanotubes is 76ml:1g), stirred at 40°C for 2 hours, centrifuged and separated, the filter cake is washed and dried at 52°C for 2 hours, and sintered under vacuum at 370°C for 3 hours to obtain carbon nanotube additive.

[0015] Glaze preparation S1: Weigh each component of the low-carbon base glaze, add it to a ball mill, add 35% of the total weight of the components of deionized water, ball mill for 3.5 hours at a speed of 320 r / min to obtain the base glaze slurry; S2: Add flake talc-mica co-modifier, carbon nanotube additive, low-carbon flux and self-cleaning modifier to the base glaze slurry, and continue ball milling for 1.2 hours to obtain a mixed glaze slurry; S3: Let the mixed glaze slurry stand for 25 minutes to remove air bubbles, then pass it through a 300-mesh sieve to obtain the finished glaze.

[0016] Glazing method for porcelain insulators Step 1: Pre-treatment of porcelain insulator blank: After forming, the blank is dried at 120℃ for 5 hours, sandblasted with diamond, cleaned with anhydrous ethanol, and then air-dried. Step 2: Glazing treatment: High-pressure electrostatic glazing, pressure 0.4MPa, glazing distance 25cm, glazing speed 6.5cm / s, glaze thickness 0.3mm; Step 3: Drying treatment: Dry at 60℃ for 2 hours, then raise the temperature to 100℃ and dry for 3.5 hours; Step 4: Firing treatment: The intelligent kiln is used for segmented firing. The temperature is increased to 400℃ at 5℃ / min and held for 1 hour; then increased to 800℃ at 3℃ / min and held for 0.5 hours; then increased to 1180℃ at 2℃ / min and held for 2.5 hours; and then cooled to room temperature at 4℃ / min. Step 5: Post-processing: Remove surface impurities, pass inspection, and obtain the finished product.

[0017] Example 2 The difference from Example 1 is that the glaze formula is as follows: 75 parts of low-carbon base glaze (25 parts of fly ash, 15 parts of coal gangue, 10 parts of kaolin, 8 parts of quartz sand, and 7 parts of limestone), 8 parts of flaky talc-mica co-modifier, 1.5 parts of carbon nanotube additive, 3 parts of low-carbon flux (1 part of borax and 2 parts of feldspar), and 1 part of self-cleaning modifier (0.75 parts of nano titanium dioxide and 0.25 parts of sodium fluorosilicate); the firing temperature is 1150℃, and the holding time is 2 hours; the rest of the preparation process and glazing method are the same as in Example 1.

[0018] Example 3 The difference from Example 1 is that the glaze formula is as follows: 85 parts of low-carbon base glaze (35 parts of fly ash, 25 parts of coal gangue, 18 parts of kaolin, 15 parts of quartz sand, and 10 parts of limestone), 12 parts of flaky talc-mica co-modifier, 3 parts of carbon nanotube additive, 5 parts of low-carbon flux (1.25 parts of borax and 3.75 parts of feldspar), and 2 parts of self-cleaning modifier (1.2 parts of nano titanium dioxide and 0.8 parts of sodium fluorosilicate); the firing temperature is 1200℃, and the holding time is 3 hours; the rest of the preparation process and glazing method are the same as in Example 1.

[0019] Scale settings To demonstrate the importance of the flaky talc-mica co-modifier and carbon nanotube additive, the following four comparative examples were set up. The remaining formulations, preparation processes, and glazing methods were the same as in Example 1: Comparative Example 1: No flake talc-mica co-modifier was added; otherwise, it was the same as Example 1. Comparative Example 2: No carbon nanotube additives were added; all other aspects were the same as in Example 1. Comparative Example 3: No flake talc-mica co-modifier and carbon nanotube additive were added; otherwise, it was the same as Example 1. Comparative Example 4: Traditional glazes were used (no industrial waste residue, no flake talc-mica co-modifiers or carbon nanotube additives were added, and the firing temperature was 1300℃). The rest of the glazing methods were the same as in Example 1. Comparative Example 5: The carbon nanotube additive was not purified, and the rest of the preparation process (non-covalent modification, coating modification, secondary coating) and formulation and glazing method were the same as in Example 1; Comparative Example 6: The carbon nanotube additive was only purified and not subjected to non-covalent modification, coating modification, or secondary coating. The rest of the preparation process, formulation, and glazing method were the same as in Example 1. Comparative Example 7: The carbon nanotube additive was purified and non-covalently modified, without coating modification or secondary coating. The rest of the preparation process, formulation and glazing method were the same as in Example 1. Comparative Example 8: The carbon nanotube additive was purified, non-covalently modified, and coated without secondary coating. The rest of the preparation process, formulation, and glazing method were the same as in Example 1.

[0020] Performance testing The performance of the porcelain insulators prepared in Examples 1-3 and Comparative Examples 1-8 was tested. The test items included: glaze-body bonding strength, water contact angle (self-cleaning performance), amount of dirt adhesion, self-cleaning rate, firing energy consumption, carbon emissions, and glaze appearance (no cracking, no peeling). The test standards and methods are as follows: 1. Glaze-body bonding strength: Tested using an adhesion tester according to GB / T 5893.5—1999 standard; 2. Water contact angle: The water contact angle on the glaze surface is measured using a contact angle measuring instrument. The larger the contact angle, the better the hydrophobic self-cleaning performance. 3. Stain Adhesion Amount: Simulating the natural environment, the sample was placed in a dusty environment for 24 hours, the mass of the adhering dust was weighed, and the stain adhesion amount per unit area was calculated. 4. Self-cleaning rate: Using the simulated rainfall method, the sample surface was rinsed with clean water, and the ratio of the residual amount of dirt after rinsing to the initial amount of dirt was calculated. Self-cleaning rate = (1 - residual amount / initial amount) × 100%; 5. Firing energy consumption: Record the power consumption per kilogram of sample during the firing process and calculate the energy consumption; 6. Carbon emissions: Calculate the carbon emissions per kilogram of sample based on fuel consumption and raw material carbon emission coefficients during the firing process; 7. Glaze appearance: Visually inspect and record whether there are defects such as cracks, peeling, and pinholes in the glaze.

[0021] Performance test results

[0022] Comparative analysis Compared with Comparative Example 1, without the addition of flake talc-mica co-modifier, the glaze-body bonding strength decreased from 30.2 MPa to 20.3 MPa, a decrease of 32.8%; the water contact angle decreased from 120° to 102°; the amount of stains adhered increased from 0.65 g / m² to 1.25 g / m²; the self-cleaning rate decreased from 94.3% to 85.7%; and localized minor cracking occurred. This indicates that the flake talc-mica co-modifier can effectively fill the voids at the glaze-body interface, improve glaze fluidity, reduce shrinkage, enhance the glaze-body bonding strength, and simultaneously improve self-cleaning performance and reduce glaze cracking. Compared with Comparative Example 2, without the addition of carbon nanotube additives, the bonding strength between the glaze and the body decreased from 30.2 MPa to 19.8 MPa, a decrease of 34.4%; the water contact angle decreased from 120° to 105°; the amount of dirt adhering increased from 0.65 g / m² to 1.18 g / m²; the self-cleaning rate decreased from 94.3% to 86.2%; and localized minor cracking occurred. This indicates that the three-dimensional network structure of the carbon nanotube additive can bridge microcracks, hinder crack propagation, and significantly improve the bonding strength between the glaze and the body. Simultaneously, the titanium dioxide coating on its surface can synergistically enhance the self-cleaning performance of the glaze with the self-cleaning modifier. Compared with Comparative Example 1 and Comparative Example 3, without the addition of either additive, the glaze-body bonding strength decreased to 14.5 MPa, a decrease of 52.0%, far lower than the decrease when only one additive was missing; the self-cleaning performance decreased significantly, the amount of stains adhered increased to 1.86 g / m², the self-cleaning rate decreased to 78.3%, and obvious cracking and local peeling occurred. This indicates that the flake talc-mica co-modifier and the carbon nanotube additive have a significant synergistic effect. The combined effect of the two can achieve a simultaneous and significant improvement in both the glaze-body bonding strength and self-cleaning performance, avoiding serious defects in the glaze layer.

[0023] Compared with Comparative Example 4, the firing energy consumption of the traditional glaze (2.58 kWh / kg) is much higher than that of the glaze of the present invention (1.85 kWh / kg), with a reduction of 28.3% in energy consumption; the carbon emission (1.08 kg CO2 / kg) is higher than that of the glaze of the present invention (0.72 kg CO2 / kg), with a reduction of 33.3% in carbon emission. Moreover, the glaze-body bonding strength and self-cleaning performance of the glaze of the present invention are better than those of the traditional glaze, indicating that the glaze of the present invention fully meets the requirements of low-carbon technology and has better overall performance. By comparing Example 1 with Comparative Examples 5-8, the necessity of different preparation steps for carbon nanotubes is demonstrated, and the specific analysis is as follows: (1) Importance of purification treatment: Comparing Example 1 (complete preparation process) and Comparative Example 5 (no purification treatment), the bonding strength of the glaze blank in Comparative Example 5 decreased to 16.9 MPa, a decrease of 44.0% compared to Example 1; the water contact angle decreased to 96°, the amount of dirt adhering increased to 1.62 g / m², the self-cleaning rate decreased to 80.5%, and local cracking and pinhole defects in the glaze layer appeared. This indicates that impurities and amorphous carbon on the surface of carbon nanotubes will affect their dispersibility and compatibility with the glaze, causing them to be unable to exert their reinforcing and synergistic self-cleaning effects. Purification treatment is the basis for ensuring the performance of carbon nanotube additives; (2) Importance of non-covalent modification: Compared with Comparative Example 6 (purified only, without modification or coating), the bonding strength of the glaze body in Comparative Example 6 was 17.5 MPa, which was 42.1% lower than that in Example 1; the self-cleaning performance was also significantly reduced, and carbon nanotubes agglomerated. This indicates that non-covalent modification can effectively improve the dispersibility of carbon nanotubes, avoid agglomeration, and enable carbon nanotubes to be uniformly dispersed in the glaze, thus ensuring their effectiveness. (3) Importance of coating modification: Comparing Example 1 and Comparative Example 7 (purified + non-covalent modification, no coating), the bonding strength of the glaze body in Comparative Example 7 was 22.3 MPa, which was 26.2% lower than that in Example 1; the water contact angle was 108° and the self-cleaning rate was 88.7%, both of which were lower than those in Example 1, and there was slight local agglomeration. This indicates that titanium dioxide coating can not only further improve the dispersibility of carbon nanotubes, but also synergistically enhance the self-cleaning performance of the glaze layer with the self-cleaning modifier, while improving the bonding stability between carbon nanotubes and glaze, and enhancing the bonding strength of the glaze body; (4) Importance of secondary coating: Comparing Example 1 and Comparative Example 8 (purification + non-covalent modification + coating modification, no secondary coating), the glaze-body bonding strength of Comparative Example 8 was 26.8 MPa, which was 11.3% lower than that of Example 1; the water contact angle was 114° and the self-cleaning rate was 91.5%, which were better than the comparative examples with missing steps, but still lower than that of Example 1. This shows that secondary coating of silica can further improve the stability of carbon nanotubes, reduce their oxidation loss during firing, and further optimize the surface properties of the glaze layer, improve the self-cleaning effect and the bonding strength of the glaze-body. In summary, the complete preparation process of carbon nanotube additives (purification → non-covalent modification → coating modification → secondary coating) is indispensable. Each step can specifically solve problems such as poor dispersion, insufficient compatibility, and insufficient function of carbon nanotubes. The synergistic effect of each step can enable carbon nanotube additives to fully exert their role in enhancing the bonding strength of glaze and body and synergistically improving self-cleaning performance, thus proving the scientific nature and necessity of the carbon nanotube additive preparation method described in this invention.

[0024] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0025] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A glaze material for improving the bonding strength between the glaze body and the glaze, characterized in that, It is composed of the following components in parts by weight: 75-85 parts of low-carbon base glaze, 8-12 parts of flake talc-mica co-modifier, 1.5-3 parts of carbon nanotube additive, 3-5 parts of low-carbon flux, and 1-2 parts of self-cleaning modifier. The low-carbon base glaze is composed of the following components in parts by weight: 25-35 parts fly ash, 15-25 parts coal gangue, 10-18 parts kaolin, 8-15 parts quartz sand, and 5-10 parts limestone.

2. The glaze for improving the bonding strength of the glaze body according to claim 1, characterized in that, The utilization rate of the industrial waste residue is ≥60%, and the carbon emissions during the production and firing process of the glaze are reduced by more than 30% compared with traditional glazes.

3. The glaze for improving the bonding strength between the glaze body and the glaze body according to claim 1, characterized in that, The self-cleaning modifier is a compound of nano-titanium dioxide and sodium fluorosilicate in a weight ratio of 3:1-2.

4. The glaze for improving the bonding strength between the glaze body and the glaze body according to claim 1, characterized in that, The low-carbon flux is a compound of borax and feldspar in a weight ratio of 1:2-3.

5. The glaze for improving the bonding strength between the glaze body and the glaze body as described in claim 1, characterized in that, The preparation method of glaze includes the following steps: S1: Weigh each component of the low-carbon base glaze according to the weight proportions, add it to a ball mill, add 30-40% of the total weight of the components of deionized water, ball mill for 3-4 hours, and the ball mill speed is 300-350 r / min to obtain the base glaze slurry. S2: Add flake talc-mica co-modifier, carbon nanotube additive, low-carbon flux and self-cleaning modifier to the base glaze slurry, and continue ball milling for 1-1.5 hours to obtain mixed glaze slurry. S3: Let the mixed glaze slurry stand for 20-30 minutes to remove air bubbles, then pass it through a 300-mesh sieve to obtain the finished glaze.

6. The glaze for improving the bonding strength between the glaze body and the glaze body as described in claim 1, characterized in that, The preparation method of the flake talc-mica co-modifier includes the following steps: Step 1: Raw material pretreatment: Select natural talc ore and mica ore, crush them and pass them through a 200-mesh sieve to remove impurities, and obtain coarse talc powder and coarse mica powder; place them in a vacuum drying oven and dry them at 80℃ for 2 hours for later use; Step 2: Flake treatment: Mix coarse talc powder and coarse mica powder at a weight ratio of 3:1-2, add to a high-speed mixer, add 0.8-1.2% of the total weight of the mixed powder with silane coupling agent KH-570, mix at high speed at 60℃ for 30 min, then send to an air jet mill, adjust the airflow speed to 20-25 m / s, and pulverize for 30-40 min to obtain flake mixed powder. The aspect ratio of the flake particles is 15-25:1, and the particle size is 10-20 μm. Step 3: Modification treatment: Add the flake mixed powder to deionized water to prepare a suspension with a mass concentration of 15-20%, ultrasonically disperse for 30 minutes, add 2-3% polyvinylpyrrolidone of the total weight of the suspension, and stir in a water bath at 60°C for 2 hours. Step 4: Drying and shaping: Vacuum filtration is used to obtain filter cake, which is then vacuum dried at 105℃ for 4-6 hours. After pulverization, the cake is passed through a 300-mesh sieve to obtain flaky talc-mica co-modifier.

7. The glaze for improving the bonding strength between the glaze body and the glaze body as described in claim 1, characterized in that, The preparation method of the carbon nanotube additive includes the following steps: Step 1: Purification of carbon nanotubes: Select multi-walled carbon nanotubes, add them to concentrated nitric acid, with a solid-liquid ratio of 1g:100ml, reflux at 120℃ for 1.5h, cool and filter, wash the filter cake twice with 5% sodium hydroxide solution, then wash with deionized water until neutral, and dry at 80℃ for 10h to obtain purified carbon nanotubes. Step 2: Non-covalent modification: Purified carbon nanotubes and polyvinylpyrrolidone were added to deionized water at a mass ratio of 1g:30mg, ultrasonically dispersed for 18h, filtered through a 0.2μm porous membrane, washed, and dried at 80℃ for 8h to obtain non-covalent modified carbon nanotubes. Step 3: Coating and Modification: Non-covalently modified carbon nanotubes were added to an 8-12 wt% isopropanol solution, ultrasonically dispersed for 25 min, and the pH was adjusted to 2.

2. Tetrabutyl titanate was added, with a ratio of non-covalently modified carbon nanotubes to tetrabutyl titanate of 1 g: 85 ml. The mixture was stirred at room temperature for 3 h and filtered to obtain a filter cake. The filter cake was washed three times alternately with anhydrous ethanol and deionized water, dried at 100 °C for 2.5 h, and sintered under vacuum at a heating rate of 8 °C / min to 460 °C for 4 h to obtain titanium dioxide / non-covalently modified carbon nanotubes. Step 4: Secondary Coating: Tetraethyl orthosilicate and anhydrous ethanol were mixed at a volume ratio of 1:1 and stirred at 60°C for 3 hours to obtain solution A; titanium dioxide / non-covalently modified carbon nanotubes, polyvinylpyrrolidone and deionized water were mixed at a mass ratio of 1g:21mg:100ml and stirred at room temperature for 20 minutes, solution A was added, and the ratio of tetraethyl orthosilicate to titanium dioxide / non-covalently modified carbon nanotubes was 76ml:1g. The mixture was stirred at 40°C for 2 hours, centrifuged and separated, and the filter cake was washed three times alternately with anhydrous ethanol and deionized water, dried at 52°C for 2 hours, and sintered under vacuum at 370°C for 3 hours to obtain carbon nanotube additive.

8. A method for glazing porcelain insulators, characterized in that, The method of using the glaze according to claim 1 includes the following steps: Step 1: Pretreatment of porcelain insulator blank: Select the formed porcelain insulator blank, dry it at 120℃ for 4-6 hours, treat the surface of the blank with diamond sandblasting, clean it with anhydrous ethanol and then air dry it. Step 2: Glazing treatment: High-pressure electrostatic glazing is used to evenly spray the glaze onto the surface of the body. The glazing pressure is 0.3-0.5MPa, the glazing distance is 20-30cm, the glazing speed is 5-8cm / s, and the glaze thickness is controlled to be 0.25-0.35mm. Step 3: Drying treatment: Dry the glazed body at 60℃ for 2 hours, then raise the temperature to 100℃ and dry for 3-4 hours; Step 4: Firing treatment: The dried green body is sent into the intelligent kiln and fired in stages: 5℃ / min to 400℃, hold for 1h; 3℃ / min to 800℃, hold for 0.5h; 2℃ / min to 1150-1200℃, hold for 2-3h; 4℃ / min to room temperature. Step 5: Post-processing: Remove surface impurities, and obtain the finished porcelain insulator after passing the inspection.

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