Antistatic water-based ceramic coating and preparation method thereof

Abstract

The invention relates to the field of antistatic coatings, in particular to an antistatic water-based ceramic coating and a preparation method thereof.The antistatic water-based ceramic coating is prepared from, by weight, 20-50 parts of silica sol, 3-10 parts of alkoxy silane, 0.5-3 parts of epoxy silane, 8-15 parts of filler, 1-6 parts of dispersing agent, 0.05-0.3 part of flatting agent, 0.05-0.4 part of defoaming agent, 0.1-0.6 part of HEUR thickener and 8-20 parts of static conductive agent; the static conductive agent is at least one of ATO, a CNT-based composite material, carbon black and AZO. Silica sol is used as a ceramic phase core and is cross-linked with alkoxy silane and epoxy silane to jointly participate in formation of a Si-O-Si network, so that a coating has excellent wear resistance and heat resistance, alkoxy silane and epoxy alkyl can endow the coating prepared from the coating with ideal adhesive force, and the wear resistance of the coating is improved. And a continuous conductive path is formed by adding the static conductive agent, so that the antistatic water-based ceramic coating with excellent performance is prepared.

Description

Technical Field

[0001] This application relates to the field of antistatic coatings, and in particular to an antistatic waterborne ceramic coating and its preparation method. Background Technology

[0002] Electric combs, curling irons, and other high-temperature hair styling tools, when in operation (typically within the temperature range of 150-230°C), easily accumulate static electricity due to the continuous friction between dry hair and the high-resistivity surface. This not only causes a stinging sensation during use but also exacerbates hair damage over time, leading to open cuticles, split ends, and breakage. Furthermore, static electricity attracts environmental dust and microorganisms, affecting hair cleanliness and health. Therefore, applying anti-static coatings to the surfaces of these small appliances is a key technological approach to improving user experience and protecting hair quality.

[0003] Existing antistatic approaches either involve adding antistatic agents, such as polyether quaternary ammonium salt antistatic agents or polymeric permanent antistatic agents, or by adding a single inorganic conductive filler to create charge dissipation pathways. However, the antistatic coatings obtained through these methods often exhibit rapid degradation of their antistatic properties during use, especially under conditions of repeated high-temperature operation and alternating cooling, and frequent friction. These coatings cannot consistently meet users' comprehensive requirements for immediate charge dissipation, low surface resistance, and long-term stability. Summary of the Invention

[0004] To improve the antistatic properties of coatings, this application provides an antistatic water-based ceramic coating and its preparation method.

[0005] Firstly, this application provides an antistatic water-based ceramic coating, which adopts the following technical solution: An antistatic water-based ceramic coating comprises the following components in parts by weight: 20-50 parts silica sol, 3-10 parts alkoxysilane, 0.5-3 parts epoxysilane, 8-15 parts filler, 1-6 parts dispersant, 0.05-0.3 parts leveling agent, 0.05-0.4 parts defoamer, 0.1-0.6 parts HEUR thickener, and 8-20 parts conductive agent; The conductive agent is at least one of ATO, CNT-based composite material, carbon black, and AZO.

[0006] By adopting the above technical solution, silica sol serves as the ceramic phase core. During the water evaporation and curing process, the silanol groups on the surface of silica particles approach each other and undergo a condensation reaction, forming strong Si-O-Si covalent bonds. After cross-linking and curing with alkoxysilanes and epoxysilanes, they jointly participate in the formation of the Si-O-Si network, forming a dense coating similar to ceramics. This coating not only has excellent wear resistance but also ideal thermal cycling resistance, meeting the application requirements of heating elements and adjacent components in small household appliances. The epoxy groups in the epoxysilane can chemically react with the hydroxyl and amino groups on the substrate surface, improving the adhesion between the coating and the substrate. Furthermore, with the addition of a conductive agent, under the action of a dispersant, the conductive agent can be uniformly dispersed in the system, forming a continuous conductive path that can quickly dissipate static charge from the substrate surface. This allows the surface resistance of the coating made from the above-mentioned antistatic water-based ceramic coating to be within 10 ohms. 6 -10 9 Electrostatic dissipation window of Ω / sq.

[0007] Among them, ATO and AZO are light-colored transparent conductive materials, while CNT and carbon black are usually black or opaque materials. However, all four have excellent conductivity and stable chemical properties, and can form effective conductive paths inside the coating. By selecting different conductive agents, different color application requirements can be met.

[0008] This application uses silica sol as the ceramic phase core. After crosslinking with alkoxysilane and epoxysilane, it can participate in the formation of Si-O-Si network to form a dense coating similar to ceramic. This coating not only has excellent wear resistance but also ideal heat resistance. Furthermore, the organic groups carried in the alkoxysilane and epoxyalkyl groups can give the coating ideal adhesion. By adding a conductive agent, a continuous conductive path can be formed in the system, thereby obtaining a high-performance antistatic waterborne ceramic coating.

[0009] Preferably, the CNT-based composite material is a CNT@SiC core-shell structured composite powder, and the preparation method of the CNT@SiC core-shell structured composite powder includes the following steps: S1. CNT powder was plasma etched under a mixed atmosphere of Ar / O2. The etched CNT powder was then dispersed in Tris-HCl buffer and ultrasonically dispersed to obtain a CNT dispersion. S2. Add dopamine hydrochloride to the CNT dispersion, stir for 12-24 hours, centrifuge to collect the lower precipitate, and obtain modified CNT powder after washing and drying. S3. Add the modified CNT powder to anhydrous ethanol and disperse it by ultrasonication to obtain a CNT ethanol dispersion. Then add the silicon source to the CNT ethanol dispersion, let it stand and mature, and then centrifuge it to collect the lower precipitate. After washing, centrifuging and drying, the precursor powder is obtained. S4. Under an inert atmosphere, the precursor powder is calcined at 1400-1600℃ for 2-4 hours and then cooled to room temperature to obtain the initial CNT@SiC core-shell composite powder. S5. The initial CNT@SiC core-shell composite powder is heated to 400-500℃ at a concentration of 5% O2 and held at that temperature for 0.5-2h. After cooling to room temperature, the CNT@SiC core-shell composite powder is obtained.

[0010] By adopting the above technical solution, oxygen-containing functional groups such as hydroxyl and carboxyl groups are first formed on the surface of CNTs through plasma etching, which also increases the surface particle size. In a weakly alkaline buffer solution, dopamine hydrochloride can self-polymerize on the surface of CNTs to form a polydopamine coating layer. Polydopamine can act as a "molecular bridge" to form covalent bonds or hydrogen bonds with the oxygen-containing functional groups on the CNT surface, achieving uniform coating of CNTs. Subsequently, the silicon source can be uniformly deposited through the coordination of amino groups on the polydopamine surface. After high-temperature calcination, a continuous and dense silicon carbide shell layer is formed, avoiding core-shell separation or shell defects. Finally, oxidation treatment can optimize the purity and density of the CNT@SiC core-shell structure and remove residual amorphous carbon impurities. At the same time, the surface of the CNT@SiC core-shell composite powder treated with S5 contains oxygen-containing functional groups, improving the dispersion stability of the CNT@SiC core-shell composite powder.

[0011] Preferably, the electrostatic agent is a mixture of ATO and CNT@SiC core-shell structured composite powder.

[0012] Preferably, the mass ratio of the ATO to the CNT@SiC core-shell composite powder is (4-9):1.

[0013] By adopting the above technical solution, ATO, a nanoscale conductive oxide particle, can form conductivity in the coating through point-to-point contact. CNT@SiC core-shell composite powder forms a conductive network in the coating through line-to-line and line-to-point contact. By compounding ATO and CNT@SiC core-shell composite powder, ATO nanoparticles are filled between CNT@SiC core-shell composite powder to form a three-dimensional conductive network of point-line-surface, which greatly reduces electron transport resistance and achieves excellent antistatic effect.

[0014] Furthermore, the hydroxyl groups on the surface of ATO can form hydrogen bonds with the hydroxyl groups on the surface of CNT@SiC core-shell composite powder, enhancing the interphase interaction. The thin layer of silica on the surface of the silicon carbide shell in CNT@SiC core-shell composite powder can form Si-O-Sn bonds with SnO2 of ATO, achieving a strong chemical bond between the two and effectively improving the hardness of the coating.

[0015] When the proportion of ATO is too high, the "bridging effect" of the CNT@SiC core-shell composite powder is weakened, requiring more ATO to form a conductive path. Furthermore, ATO, being a rigid sphere, is prone to agglomeration during dispersion, leading to discontinuous conductive paths and "breakpoints." This reduces the antistatic performance of the antistatic waterborne ceramic coating. Additionally, the interfacial bonding between ATO and the ceramic network is merely physical adsorption, resulting in weak interfacial forces and decreased wear resistance. Conversely, when the proportion of ATO is too low, insufficient ATO addition cannot adequately separate the CNT@SiC core-shell composite powder, making it prone to agglomeration. Excessive CNT@SiC core-shell composite powder may also lead to overconductivity, increasing the risk of sudden discharge.

[0016] Preferably, the filler includes at least one of boehmite, nano-alumina, mica powder, and hexagonal boron nitride.

[0017] By adopting the above technical solution, boehmite, an aluminum hydroxy oxide, is a plate-like or needle-like crystal that can be oriented parallel to the substrate surface in the coating, effectively improving the wear resistance of the coating.

[0018] Nano-alumina is one of the hardest oxides and can fill the tiny gaps between silica sol particles and other fillers, effectively improving the hardness and wear resistance of the coating.

[0019] Mica powder is a layered silicate mineral. Its flaky structure is larger and more complete than that of boehmite, which helps to improve the corrosion resistance of the coating. In addition, the flaky structure of mica powder can effectively prevent the propagation of cracks and improve the flexibility of the coating.

[0020] The crystal structure of hexagonal boron nitride is similar to that of graphene, consisting of a hexagonal layered structure composed of alternating boron and nitrogen atoms. It has excellent thermal conductivity and electrical insulation, and the layers can slide easily, giving the coating a lower coefficient of friction.

[0021] Preferably, the antistatic waterborne ceramic coating also contains at least one of zirconium sol and aluminum sol.

[0022] By adopting the above technical solution, zirconium ions in zirconium sol undergo hydrolysis-condensation reaction during the curing process to form a dense Zr-O-Zr inorganic network. Furthermore, zirconium ions have extremely strong coordination ability and can undergo condensation reaction with -Si-OH and -C-OH on the surface of CNT@SiC core-shell composite powder and -OH on the surface of ATO, thereby fixing conductive particles. They can also form "Al-O-Zr" bonds with -Al-OH on the filler surface, strengthening the bond between the filler and the matrix.

[0023] The Al-O-Al network formed by the hydrolysis and polymerization of aluminum ions in aluminum sol has extremely strong adsorption and bonding capabilities, and can form a "physical adsorption + chemical bond" with the substrate surface, greatly improving the adhesion of the coating.

[0024] Preferably, the mass ratio of the silica sol to the zirconium sol is 1:(0.2-0.5).

[0025] By adopting the above technical solution, silica sol and zirconium sol are compounded. The silanol groups on the surface of silica in silica sol will undergo a co-condensation reaction with the zirconium ol groups in zirconium sol to form stable Si-O-Zr covalent bonds. This allows the originally independent Si-O-Si network and Zr-O-Zr network to interpenetrate and tightly combine, forming an "interpenetrating hybrid inorganic network", which effectively improves the hardness and wear resistance of the coating.

[0026] When the proportion of silica sol is too large, there is a lack of sufficient Zr-O bonds and the reinforcing effect of hard ZrO2 nanoparticles, and the hardness and wear resistance of the coating cannot meet expectations. When the proportion of silica sol is too small, a high proportion of zirconium sol may disrupt the charge balance of the entire sol system, resulting in a shorter coating shelf life and easy gelation or sedimentation.

[0027] Preferably, the antistatic water-based ceramic coating also contains phytic acid, wherein the amount of phytic acid added is 0.5-3 parts.

[0028] By employing the above technical solution, phytic acid contains six strongly complexing phosphate groups in its molecular structure. These phosphate groups can undergo a strong chelation reaction with metal atoms in the metal substrate to form a stable, insoluble phytic acid-metal complex. Simultaneously, the hydroxyl groups in phytic acid can undergo a condensation reaction with the hydroxyl groups in the silica sol and zirconium sol networks to form a dense Si-O-Zr-P quaternary composite network, effectively improving the adhesion of the coating.

[0029] In addition, the hydroxyl groups of phytic acid can adsorb onto the surface of CNT@SiC core-shell composite powder, improving the compatibility of CNT@SiC core-shell composite powder with aqueous systems. Simultaneously, the adsorption layer formed by phytic acid molecules, combined with the steric hindrance effect of the dispersant, creates a dual stabilizing mechanism of "electrostatic repulsion + steric hindrance," inhibiting the aggregation of CNT@SiC core-shell composite powder. Furthermore, phytic acid molecules can simultaneously bond to 2-3 CNT@SiC particles, connecting isolated CNT@SiC particles into "chain-like conductive pathways," avoiding conductive gaps caused by the dispersion of single particles. The Si-O-Zr-P network formed by phytic acid, silica sol, and zirconium sol can firmly encapsulate and fix the "chain-like conductive pathways," forming a "rigid conductive framework." This prevents the migration and aggregation of CNT@SiC particles during film formation or use, and also prevents CNTs from being oxidized and eroded, thus achieving excellent antistatic properties of the coating.

[0030] When the amount of phytic acid added is too low, there are not enough phosphate groups to react with the metal atoms in the metal substrate, so the adhesion between the coating and the metal substrate is not significantly improved. When the amount of phytic acid added is too high, since phytic acid is an organic material, its thermal stability and mechanical strength are much lower than those of inorganic silicon-zirconium networks. The addition of excessive phytic acid will lead to a decrease in the hardness and wear resistance of the coating.

[0031] Secondly, the antistatic water-based ceramic coating provided in this application adopts the following technical solution: A method for preparing an antistatic water-based ceramic coating includes the following steps: Step 1: After adjusting the pH of the silica sol to 3.2-5.2, add alkoxysilane and epoxysilane while stirring to obtain a sol-silane mixture; Step 2: Add the prescribed amount of antistatic agent and filler to the dispersant aqueous solution, mix well, and obtain a mixed slurry; Step 3: Add the mixed slurry to the silica sol-silane mixture, stir and mix, then add the leveling agent, defoamer and thickener according to the formula, and mix to obtain the antistatic water-based ceramic coating.

[0032] By adopting the above technical solution, a sol-silane mixture is first formed by silica sol, alkoxysilane and epoxysilane, which provides a rigid dispersion matrix for the antistatic agent. Then, by adding the antistatic agent and filler to the dispersant, the uniform dispersion of the antistatic agent and filler is promoted. When the mixed slurry is mixed with the sol-silane mixture, the antistatic agent and filler can form a continuous conductive path in the three-dimensional network, thereby obtaining a high-performance antistatic waterborne ceramic coating.

[0033] Preferably, in step 1, after adjusting the pH of the silica sol to 3.2-5.2, zirconium sol and / or aluminum sol, alkoxysilane and epoxysilane are added under stirring to obtain a sol-silane mixture; in step 2, the prescribed amount of phytic acid is first added to the dispersant aqueous solution, and then the prescribed amount of electrostatic agent and filler are added and mixed evenly to obtain a mixed slurry.

[0034] By adopting the above technical solution, zirconium sol and aluminum sol are added in step 1 so that they can cooperate with silica sol, alkoxysilane and epoxysilane to form a multi-element inorganic network. Phytic acid is added in step 2 so that it can chelate with hydroxyl groups and metal ions on the surface of the conductive agent and filler, thereby further improving the dispersibility of the conductive agent and filler and synergistically improving the performance of the antistatic waterborne ceramic coating.

[0035] In summary, this application includes at least one of the following beneficial technical effects: 1. This application uses silica sol as the ceramic phase core. After crosslinking with alkoxysilane and epoxysilane, it can participate in the formation of Si-O-Si network to form a dense coating similar to ceramic. This coating not only has excellent wear resistance but also ideal heat resistance. Furthermore, the organic groups carried in alkoxysilane and epoxyalkyl can give the coating ideal adhesion. With the addition of a conductive agent, a continuous conductive path can be formed in the system, thereby obtaining a high-performance antistatic waterborne ceramic coating. 2. This application combines silica sol and zirconium sol. The silanol groups on the surface of silica in silica sol will undergo a condensation reaction with the zirconium hydroxyl groups in zirconium sol to form stable Si-O-Zr covalent bonds. This allows the originally independent Si-O-Si network and Zr-O-Zr network to interpenetrate and tightly combine to form an "interpenetrating hybrid inorganic network", which effectively improves the hardness and wear resistance of the coating. 3. By adding phytic acid, this application can react with the hydroxyl groups in the silica sol and zirconium sol networks to form a dense Si-O-Zr-P quaternary composite network, which effectively improves the adhesion of the coating. At the same time, it can also promote the dispersibility of CNT@SiC core-shell structure composite powder and connect isolated CNT@SiC particles into a "chain conductive path". Detailed Implementation

[0036] The raw materials in this application include the following: Silica sol: Silica sol with a silica content of 10-40% can be selected. This application takes silica sol with a silica content of 30% from Dongguan Huihe Yongsheng Nanotechnology Co., Ltd. as an example. Alkoxysilanes: Commercially available products with CAS number 1185-55-3 are used; Epoxysilane: Commercially available products with CAS number 2530-83-8 are used; Boehmite: Using commercially available products with CAS number 1318-23-6; Nano-alumina: Alumina with a particle size of 10-30nm can be used. This application takes nano-alumina with a particle size of 20nm from Shenzhen Jingcai Chemical Co., Ltd. as an example. Mica powder: 5-15μm mica powder can be used. This application takes 10μm mica powder from Lingshou County Derui Mining Co., Ltd. as an example. Hexagonal boron nitride: 1-5μm hexagonal boron nitride can be used. This application takes hexagonal boron nitride with a particle size of 3μm from Shandong Pengcheng Ceramic New Material Technology Co., Ltd. as an example. Dispersant: Polycarboxylate and polyamide salts can be used. This application takes the polycarboxylate from Dongying Xinwang Chemical Co., Ltd. as an example. Leveling agent: This application takes polyether-modified siloxane with CAS number 128192-17-6 as an example; Defoamer: mineral oil and polyether can be used. This application takes mineral oil with CAS number 8042-47-5 as an example. HEUR Thickener: The product used is the commercially available product L1400 from Shenzhen Longgang District Jiyichang New Material Marketing Planning Center; ATO: ATO with a particle size of 20-30nm can be selected. This application takes ATO with a particle size of 25nm from Qinghe County Chaotai Metal Materials Co., Ltd. as an example. CNTs: CNTs with a particle size of 10-30μm can be selected. This application takes CNTs with a particle size of 10μm from Ningbo Luofei Nanotechnology Co., Ltd. as an example. Dopamine hydrochloride: Dopamine hydrochloride with CAS number 62-31-7 is used; Silicon source: TEOS with CAS number 78-10-4; AZO: AZO with a particle size of 20-40nm can be selected. This application takes AZO with a particle size of 30nm from Hubei Greet Biomedical Technology Co., Ltd. as an example. Sodium dodecyl sulfonate: Uses a commercially available product with CAS number 2386-53-0; Phytic acid: Commercially available product with CAS number 83-86-3 is used.

[0037] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0038] Example 1

[0039] A method for preparing an antistatic water-based ceramic coating includes the following steps: Step 1: Add 10% glacial acetic acid to 350g of silica sol to adjust the pH of the system to 4.2, then put it into a disperser for stirring. While stirring, add 60g of alkoxysilane and 15g of epoxysilane. Continue stirring for 30min to obtain a sol-silane mixture. The speed of the disperser is 400rpm and the temperature is 25℃. Step 2: Dissolve 30g of polycarboxylate in water to prepare a dispersant aqueous solution with a concentration of 0.3wt%. Add 140g of antistatic agent and 120g of filler to the dispersant aqueous solution, mix well, and obtain a mixed slurry. Step 3: Add the mixed slurry to the silica sol-silane mixture, stir and mix, then add 2g of leveling agent, 2.5g of defoamer and 3g of thickener, adjust the viscosity at 25℃ to 800mPa·s, and obtain the antistatic water-based ceramic coating.

[0040] The filler is a mixture of 30g boehmite, 50g mica powder, and 40g hexagonal boron nitride. The electrostatic agent is a mixture of ATO and CNT@SiC core-shell composite powder, with a mass ratio of ATO to CNT@SiC core-shell composite powder of 7:1.

[0041] The preparation method of CNT@SiC core-shell structured composite powder includes the following steps: S1. CNT powder was plasma etched for 20 min in a mixed atmosphere with an Ar / O2 volume ratio of 4:1. The etched CNT powder was then dispersed in a Tris-HCl buffer solution with a pH of 8.5 and ultrasonically dispersed for 30 min to obtain a CNT dispersion. The radio frequency power of the plasma etching was 100 W and the system pressure was 20 Pa. S2. Add 0.5 mg / mL dopamine hydrochloride to the CNT dispersion, stir for 18 h, centrifuge at 10000 rpm for 5 min, collect the lower precipitate, wash it, and dry it in a vacuum drying oven at 50℃ for 8 h to obtain modified CNT powder. S3. Add the modified CNT powder to anhydrous ethanol and ultrasonically disperse for 30 min to obtain a CNT ethanol dispersion. Then add the silicon source to the CNT ethanol dispersion, let it stand for 24 h and then centrifuge at 10000 rpm for 5 min. Collect the lower precipitate, wash, centrifuge and dry to obtain the precursor powder. The mass ratio of silicon source to CNT is 3:1. S4. Under an argon atmosphere, the precursor powder was heated to 1500℃ at a rate of 3℃ / min and calcined for 3h. After cooling to room temperature, the initial CNT@SiC core-shell structure composite powder was obtained. S5. The initial CNT@SiC core-shell composite powder was heated to 450℃ at a concentration of 5% O2 and held for 1 hour. After cooling to room temperature, the CNT@SiC core-shell composite powder was obtained.

[0042] Example 2-3 Examples 2-3 are based on the preparation method of Example 1, but the formulation amount of antistatic waterborne ceramic coating is adjusted, as shown in Table 1.

[0043] Comparative Examples 1-2 Comparative Examples 1-2 are based on the preparation method of Example 1, but the formulation amount of the antistatic waterborne ceramic coating is adjusted, as shown in Table 1.

[0044] Comparative Example 3 Comparative Example 3 was prepared using the same method as in Example 1, but with the electrostatic agent replaced by an equal amount of sodium dodecyl sulfonate, while all other conditions remained unchanged.

[0045] Performance testing An antistatic water-based ceramic coating is applied to a metal workpiece and then cured. The curing process consists of three stages: the first stage is cured at 80°C for 10 minutes, the second stage is cured at 160°C for 10 minutes, and the final stage is cured at 245°C for 25 minutes. Finally, the workpiece with the antistatic water-based ceramic coating is obtained by cooling.

[0046] The antistatic waterborne ceramic coatings of Examples 1-3 and Comparative Examples 1-3 were analyzed using the following specific testing methods: 1. Wear resistance The abrasion resistance of antistatic waterborne ceramic coatings was tested using the standard method specified in ASTM D4060, employing a Taber abrasion tester, a CS-10 abrasion wheel, a 500g load, and 500 revolutions.

[0047] 2. Antistatic properties According to the standard test method specified in ASTM D257, under the conditions of 23℃ / 50%RH, after applying the test voltage, wait 60 seconds and record the resistance value.

[0048] 3. Heat cycling resistance The workpiece with an antistatic water-based ceramic coating was cyclically subjected to 20 cycles at room temperature and 230°C, and the resistance value was measured after the cycles.

[0049] 4. Adhesion The adhesion of antistatic water-based ceramic coatings was tested using the standard test method specified in GB / T 9286.

[0050] Based on the above detection method, the test results of Examples 1-3 and Comparative Examples 1-3 were obtained, as shown in Table 1 below.

[0051] Table 1. Formulation composition and performance test results of antistatic agent waterborne ceramic coatings in Examples 1-3 and Comparative Examples 1-3.

[0052] Referring to Table 1, comparing Examples 1-3 and Comparative Examples 1-2, it can be seen that the performance of the antistatic waterborne ceramic coatings of Examples 1-3 is significantly better than that of the antistatic waterborne ceramic coatings of Comparative Examples 1-2. This may be because the compounding of alkoxysilane and epoxysilane results in the formation of an inorganic network with high hardness and low coefficient of friction through hydrolysis and condensation of alkoxysilane. As a "wear-resistant substrate" for the coating, it can directly resist the damage to the coating caused by external scratches and friction. Epoxysilane forms a "double cross-linked structure" with the silicon-oxygen network of alkoxysilane through ring-opening cross-linking of epoxy groups. The resulting inorganic network can limit the dispersion of the conductive agent, enabling it to form a continuous conductive path.

[0053] By comparing Examples 1-3 and Comparative Example 3, it can be seen that the addition of the conductive agent in this application results in a better performance of the antistatic waterborne ceramic coating compared to the ionic antistatic agent sodium dodecyl sulfonate. This may be because the ionic antistatic agent relies on absorbing ambient moisture and ionizing ions to conduct electricity, and its effect is heavily dependent on ambient humidity. In contrast, the conductive agent in this application forms a conductive path through physical contact, and its effect is permanent and stable, and is basically unaffected by humidity. Therefore, after thermal cycling, the conductivity of the antistatic waterborne ceramic coating prepared in this application will not be greatly affected.

[0054] Examples 4-7 Examples 4-7 are based on the preparation method of Example 1, but the type of conductive agent is adjusted, as shown in Table 2.

[0055] Performance testing The antistatic waterborne ceramic coatings of Examples 1 and 4-7 were analyzed using the following specific testing methods: 1. Hardness The hardness of the antistatic waterborne ceramic coating was tested according to the standard testing method specified in GB / T 6739.

[0056] Based on the above detection method, the test results of Example 1 and Examples 4-7 were obtained, as shown in Table 2 below.

[0057] Table 2. Types of conductive agents and their performance test results in Examples 1 and 4-7.

[0058] Referring to Table 2, a comparison of Examples 1 and 4-7 shows that the antistatic waterborne ceramic coating of Example 1 exhibits the best performance. This may be because ATO is a nanoscale conductive oxide particle that can form conductivity in the coating through point-to-point contact. The CNT@SiC core-shell composite powder forms a conductive network in the coating through line-to-line and line-to-point contact. By compounding ATO and CNT@SiC core-shell composite powder, ATO nanoparticles are filled between the CNT@SiC core-shell composite powder particles to form a three-dimensional conductive network of point-to-line-to-surface, which significantly reduces electron transport resistance and achieves excellent antistatic effect.

[0059] Furthermore, the hydroxyl groups on the surface of ATO can form hydrogen bonds with the hydroxyl groups on the surface of CNT@SiC core-shell composite powder, enhancing the interphase interaction. The silicon dioxide thin layer on the surface of the silicon carbide shell in CNT@SiC core-shell composite powder forms Si-O-Sn bonds with SnO2 of ATO, achieving a strong chemical bond between the two and effectively improving the hardness of the coating.

[0060] Examples 8-11 Examples 8-11 are based on the preparation method of Example 1, but the mixing mass ratio of ATO and CNT@SiC core-shell structure composite powder is adjusted as shown in Table 3.

[0061] The water-based antistatic ceramic coatings of Examples 8-11 were subjected to the above-mentioned performance tests, and the test results are shown in Table 3.

[0062] Table 3. Mixing mass ratio and performance test results of ATO and CNT@SiC core-shell structured composite powders in Examples 1 and 8-11.

[0063] Referring to Table 3, a comparison of Examples 1 and 8-11 shows that the antistatic waterborne ceramic coating exhibits the best performance when the mass ratio of ATO to CNT@SiC core-shell composite powder is (4-9):1, especially when the mass ratio is 7:1. This may be because when the proportion of ATO is too high, the "bridging effect" of the CNT@SiC core-shell composite powder is weakened, requiring more ATO to form a conductive path. Furthermore, ATO is a rigid sphere and is prone to agglomeration during dispersion. This leads to discontinuous conductive pathways and "breakpoints," resulting in a decrease in the antistatic performance of the waterborne antistatic ceramic coating. Furthermore, the interfacial bonding between ATO and the ceramic network is only physical adsorption, with weak interfacial forces, leading to a decrease in the wear resistance of the waterborne antistatic ceramic coating. When the proportion of ATO is too small, the amount of ATO added is insufficient and cannot adequately separate the CNT@SiC core-shell composite powder, making the CNT@SiC core-shell composite powder prone to agglomeration. In addition, excessive CNT@SiC core-shell composite powder may lead to over-conductivity and a risk of sudden discharge.

[0064] Example 12 Example 12 is based on the preparation method of Example 1, except that boehmite is replaced with an equal amount of nano-alumina, while the other conditions remain unchanged.

[0065] Example 13 Example 13 is based on the preparation method of Example 1, except that 30g of boehmite is replaced with 15g of boehmite and 15g of nano-alumina, while the other conditions remain unchanged.

[0066] Performance testing The antistatic waterborne ceramic coatings of Examples 1 and 12-13 were analyzed using the following specific testing methods: 1. Coefficient of friction The antistatic water-based ceramic coating was subjected to 1000 cycles of reciprocating friction between a ball and a disk under conditions of 1 N and 0.1 m / s, and its coefficient of dynamic friction was measured.

[0067] Based on the above detection method, the test results of Example 1 and Examples 12-13 were obtained, as shown in Table 4 below.

[0068] Table 4. Packing materials and their performance test results for Examples 1 and 12-13.

[0069] Referring to Table 4, a comparison of Examples 1 and 12-13 shows that the addition of fillers, boehmite and nano-alumina help to improve the hardness and wear resistance of antistatic waterborne ceramics, while mica powder and hexagonal boron nitride help to impart a lower coefficient of friction to the antistatic waterborne ceramic coating, thereby obtaining a high-performance antistatic waterborne ceramic coating.

[0070] Example 14 Example 14 is based on the preparation method of Example 1. In step 1, after adjusting the pH of the silica sol to 4.2, zirconium sol, alkoxysilane and epoxysilane are added under stirring to obtain a sol-silane mixture. The mass ratio of silica sol to zirconium sol is 1:0.3, and the other conditions remain unchanged.

[0071] Example 15 Example 15 is based on the preparation method of Example 14, except that the zirconium sol is replaced with an equal amount of aluminum sol, while the other conditions remain unchanged.

[0072] The antistatic waterborne ceramic coatings of Examples 14-15 were subjected to the above-mentioned performance tests, and the test results are shown in Table 5.

[0073] Table 5 Performance test results for Examples 1 and 14-15

[0074] Referring to Table 5, a comparison of Examples 1 and 14-15 shows that the addition of zirconium sol and aluminum sol helps to improve the performance of antistatic waterborne ceramic coatings. This may be because zirconium ions in the zirconium sol undergo hydrolysis-condensation reactions during the curing process, forming a dense Zr-O-Zr inorganic network. Furthermore, zirconium ions have extremely strong coordination ability, enabling them to undergo condensation reactions with -Si-OH and -C-OH on the surface of CNT@SiC core-shell composite powder and -OH on the surface of ATO, thereby fixing conductive particles. They can also form "Al-O-Zr" bonds with -Al-OH on the filler surface, strengthening the bond between the filler and the matrix.

[0075] The Al-O-Al network formed by the hydrolysis and polymerization of aluminum ions in aluminum sol has extremely strong adsorption and bonding capabilities, and can form a "physical adsorption + chemical bonding" with the substrate surface, greatly improving the adhesion of the coating.

[0076] Examples 16-19 Examples 16-19 are based on the preparation method of Example 14, but the mixing mass ratio of silica sol and zirconium sol is adjusted as shown in Table 6.

[0077] Performance testing The antistatic waterborne ceramic coatings of Examples 14 and 16-19 were analyzed using the following specific testing methods: 1. Stability After placing the antistatic water-based ceramic coating sample in a 50℃ oven for 7 days, place it in a high-speed refrigerated centrifuge, set it to 25℃, and centrifuge at 2000r / min for 10 minutes. Visually inspect the bottom for any sediment.

[0078] Based on the above detection method, the test results of Examples 14 and 16-19 were obtained, as shown in Table 6 below.

[0079] Table 6. Mixing mass ratio of silica sol and zirconium sol and their performance test results in Examples 14 and 16-19.

[0080] Referring to Table 6, a comparison of Examples 14 and 16-19 shows that when the mass ratio of silica sol to zirconium sol is 1:(0.2-0.5), especially when the mass ratio of silica sol to zirconium sol is 1:0.3, the resulting antistatic waterborne ceramic coating exhibits the best performance. This may be because when the proportion of silica sol is too high, there is a lack of sufficient Zr-O bonds and the reinforcing effect of hard ZrO2 nanoparticles, and the hardness and wear resistance of the coating cannot meet expectations. When the proportion of silica sol is too low, a high proportion of zirconium sol may disrupt the charge balance of the entire sol system, resulting in a shorter coating shelf life and making it prone to gelation or sedimentation.

[0081] Example 20 Example 20 is based on the preparation method of Example 14. In step 2, 20g of phytic acid is first added to the dispersant aqueous solution, and then the formulated amount of electrostatic agent and filler are added and mixed evenly to obtain a mixed slurry. The other conditions remain unchanged.

[0082] Examples 21-24 Examples 21-24 are based on the preparation method of Example 20, but the amount of phytic acid added is adjusted, as shown in Table 7.

[0083] The antistatic waterborne ceramic coatings of Examples 20-24 were subjected to the above-mentioned performance tests, and the test results are shown in Table 7.

[0084] Table 7. Phytic acid addition amount and performance test results for Examples 14 and 20-24

[0085] Referring to Table 7, a comparison of Examples 14 and 20 shows that the addition of phytic acid helps improve the performance of antistatic waterborne ceramic coatings. This may be because the phosphate groups in phytic acid can chelate with metal ions in the metal substrate, and its hydroxyl groups can also undergo condensation reactions with the hydroxyl groups of silica sol and zirconium sol to form a dense Si-O-Zr-P quaternary composite network, effectively improving the adhesion of the coating. Furthermore, the hydroxyl groups of phytic acid can adsorb onto the surface of the CNT@SiC core-shell composite powder, inhibiting the aggregation of the CNT@SiC core-shell composite powder and connecting isolated CNT@SiC particles into a "chain-like conductive pathway," forming an excellent conductive pathway.

[0086] Comparative examples 20-24 show that when the amount of phytic acid added is too low, there are not enough phosphate groups to react with the metal atoms in the metal substrate, resulting in a lack of significant improvement in the adhesion between the coating and the metal substrate. When the amount of phytic acid added is too high, since phytic acid is an organic substance, its thermal stability and mechanical strength are much lower than those of the inorganic silicon-zirconium network. The addition of excessive phytic acid will lead to a decrease in the hardness and wear resistance of the coating.

[0087] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An antistatic water-based ceramic coating, characterized in that, The product comprises the following components in parts by weight: 20-50 parts silica sol, 3-10 parts alkoxysilane, 0.5-3 parts epoxysilane, 8-15 parts filler, 1-6 parts dispersant, 0.05-0.3 parts leveling agent, 0.05-0.4 parts defoamer, 0.1-0.6 parts HEUR thickener, and 8-20 parts antistatic agent; The conductive agent is at least one of ATO, CNT-based composite material, carbon black, and AZO.

2. The antistatic water-based ceramic coating according to claim 1, characterized in that, The CNT-based composite material is a CNT@SiC core-shell structured composite powder, and the preparation method of the CNT@SiC core-shell structured composite powder includes the following steps: S1. CNT powder was plasma etched under a mixed atmosphere of Ar / O2. The etched CNT powder was then dispersed in Tris-HCl buffer and ultrasonically dispersed to obtain a CNT dispersion. S2. Add dopamine hydrochloride to the CNT dispersion, stir for 12-24 hours, centrifuge to collect the lower precipitate, and obtain modified CNT powder after washing and drying. S3. Add the modified CNT powder to anhydrous ethanol and disperse it by ultrasonication to obtain a CNT ethanol dispersion. Then add the silicon source to the CNT ethanol dispersion, let it stand and mature, and then centrifuge it to collect the lower precipitate. After washing, centrifuging and drying, the precursor powder is obtained. S4. Under an inert atmosphere, the precursor powder is calcined at 1400-1600℃ for 2-4 hours and then cooled to room temperature to obtain the initial CNT@SiC core-shell composite powder. S5. The initial CNT@SiC core-shell composite powder is heated to 400-500℃ at a concentration of 5% O2 and held at that temperature for 0.5-2h. After cooling to room temperature, the CNT@SiC core-shell composite powder is obtained.

3. The antistatic water-based ceramic coating according to claim 2, characterized in that, The electrostatic agent is a mixture of ATO and CNT@SiC core-shell structured composite powder.

4. The antistatic water-based ceramic coating according to claim 3, characterized in that, The mass ratio of the ATO to the CNT@SiC core-shell composite powder is (4-9):

1.

5. The antistatic water-based ceramic coating according to claim 1, characterized in that, The filler includes at least one of boehmite, nano-alumina, mica powder, and hexagonal boron nitride.

6. The antistatic water-based ceramic coating according to claim 1, characterized in that, It also contains at least one of zirconium sol and aluminum sol.

7. The antistatic water-based ceramic coating according to claim 6, characterized in that, The mass ratio of the silica sol to the zirconium sol is 1:(0.2-0.5).

8. The antistatic water-based ceramic coating according to claim 7, characterized in that, Phytic acid is also added, with an addition amount of 0.5-3 parts.

9. The method for preparing an antistatic waterborne ceramic coating according to claims 1-8, characterized in that, Includes the following steps: Step 1: After adjusting the pH of the silica sol to 3.2-5.2, add the prescribed amounts of alkoxysilane and epoxysilane while stirring to obtain a sol-silane mixture; Step 2: Add the prescribed amount of antistatic agent and filler to the dispersant aqueous solution, mix well, and obtain a mixed slurry; Step 3: Add the mixed slurry to the silica sol-silane mixture, stir and mix, then add the leveling agent, defoamer and thickener according to the formula, and mix to obtain the antistatic water-based ceramic coating.

10. The method for preparing an antistatic waterborne ceramic coating according to claim 9, characterized in that, In step 1, after adjusting the pH of the silica sol to 3.2-5.2, zirconium sol and / or aluminum sol, alkoxysilane and epoxysilane are added under stirring to obtain a sol-silane mixture; in step 2, the prescribed amount of phytic acid is first added to the dispersant aqueous solution, and then the prescribed amount of electrostatic agent and filler are added and mixed evenly to obtain a mixed slurry.

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