Long-acting bacteriostatic easy-to-clean daily-use ceramic material and preparation method thereof

Abstract

The application discloses a long-acting bacteriostatic easy-to-clean daily-use ceramic material and a preparation method thereof, and belongs to the technical field of new daily-use ceramic materials. The ceramic material comprises a ceramic base body, a bottom glaze layer, a functional surface glaze layer and a transparent protective glaze layer which are sequentially coated on the surface of the ceramic base body. Ag + / Cu 2+ / La 3+ modified sepiolite powder is introduced into the ceramic base body, so that sustained ion release antibacterial effect is realized in dark places; graphene composite modified nano-titanium dioxide is added into the functional surface glaze layer, so that strong oxidizing active oxygen species are generated under visible light to directly kill bacteria and endow the glaze surface with persistent super-hydrophilic characteristics. The two cooperate with each other to form a long-acting antibacterial system, and the photocatalytic super-hydrophilic surface makes oil stains easy to be washed away by water, so that the prepared ceramic material has a good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of new materials preparation technology for daily-use ceramics, specifically to a long-lasting antibacterial and easy-to-clean daily-use ceramic material and its preparation method. Background Technology

[0002] Daily-use ceramics are the most widely used materials for tableware, teaware, and kitchen and bathroom utensils in daily life, possessing advantages such as safety and non-toxicity, a warm and smooth texture, corrosion resistance, and high-temperature resistance. With the upgrading of residents' demands for healthy living, functional daily-use ceramics with antibacterial, easy-to-clean, and stain-resistant properties have become a hot research topic in the industry.

[0003] Currently, antibacterial and easy-to-clean ceramics on the market mainly suffer from three major technical shortcomings: First, the antibacterial system has poor stability. Traditional single nano-silver and nano-zinc antibacterial agents are prone to oxidation, aggregation, precipitation, and loss during the high-temperature sintering process of ceramics. After short-term use, the antibacterial performance is greatly reduced, and long-term antibacterial effect cannot be achieved. Moreover, excessive precipitation of silver ions poses a food safety hazard. Second, the easy-to-clean performance is not durable enough. Most existing ceramics use a post-spraying hydrophobic coating to achieve the easy-to-clean effect. The coating only adheres to the surface of the glaze and has poor high-temperature resistance and scrubbing resistance. After repeated washing and tableware disinfection, the coating falls off, and the easy-to-clean function is completely lost. Third, the functional components have poor compatibility with the glaze. The addition of functional additives can easily lead to defects such as pinholes, haze, and color difference on the glaze surface, destroying the transparency and aesthetics of daily-use ceramics, while also reducing the mechanical strength and wear resistance of the glaze surface.

[0004] In existing technologies, most solutions only optimize antibacterial or easy-to-clean properties, failing to achieve long-term synergistic stability of dual functions. Furthermore, these solutions involve complex preparation processes and low firing yields, making it difficult to meet the mass production and long-term use requirements of high-end daily-use ceramics. Therefore, developing a daily-use ceramic material that combines long-lasting antibacterial properties, durable and easy-to-clean characteristics, excellent glaze quality, and process adaptability for mass production is a pressing technical problem that needs to be solved in this field. Summary of the Invention

[0005] This invention provides a long-lasting antibacterial and easy-to-clean daily-use ceramic material. The invention utilizes a composite modified sepiolite powder in the ceramic body and graphene-modified nano-titanium dioxide in the functional glaze layer to form a dual-functional layer system for all-weather slow-release and photocatalytic synergistic antibacterial action. This achieves a long-lasting, broad-spectrum, and stable antibacterial effect, while simultaneously endowing the glaze with durable and easy-to-clean properties. It achieves long-lasting synergy in both antibacterial and easy-to-clean functions, while ensuring a transparent and smooth ceramic glaze surface with excellent mechanical properties. The preparation process is simple and controllable, with strong mass production stability.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: A long-lasting antibacterial and easy-to-clean daily ceramic material includes a ceramic body, a base glaze layer covering the surface of the ceramic body, a functional surface glaze layer covering the surface of the base glaze layer, and a transparent protective glaze layer covering the surface of the functional surface glaze layer. The ceramic body is made from the following raw materials in parts by weight: 45-55 parts kaolin, 20-28 parts potassium feldspar, 12-18 parts quartz sand, 3-6 parts talc, 2-4 parts calcite, 5-10 parts modified sepiolite powder, and 30-40 parts deionized water. The base glaze layer is made from the following raw materials in parts by weight: 35-42 parts albite, 22-28 parts quartz, 10-15 parts calcined kaolin, 6-10 parts wollastonite, 3-5 parts zinc oxide, 8-12 parts lead-free boron frit, and 25-32 parts deionized water; the thickness of the base glaze layer is 0.10-0.30 mm. The functional glaze layer is made from the following raw materials in parts by weight: 75-85 parts of base glaze, 6-10 parts of graphene composite modified nano titanium dioxide, 0.5-1.2 parts of dispersant, 1-2 parts of flux, and 18-25 parts of deionized water; the thickness of the functional glaze layer is 0.05-0.15 mm; and the thickness of the transparent protective glaze layer is 5-15 μm.

[0007] Preferably, the modified sepiolite powder is prepared by the following method: (1) Crush natural sepiolite powder through a 200-mesh sieve, then immerse it in 0.1 mol / L hydrochloric acid solution at a solid-liquid ratio of 1 g: 10 mL, microwave it for 10-15 min, filter and wash it until neutral, and dry it. (2) Place the product obtained in step (1) in a muffle furnace, heat it to 200℃ at 2℃ / min and hold it for 60min; then heat it to 350℃ at 3℃ / min and hold it for 90min; finally heat it to 450℃ at 1℃ / min and hold it for 120min. After cooling to room temperature, grind it to obtain calcined sepiolite powder. (3) Immerse the calcined sepiolite powder in a composite metal ion solution at a solid-liquid ratio of 1g:15mL, stir at 70-75℃ for 5-6h, filter, wash with deionized water 3-5 times, and dry. (4) Disperse the product obtained in step (3) in a mixed solution of tetraethyl orthosilicate and anhydrous ethanol in a volume ratio of 1:5, add ammonia to adjust the pH of the system to 8-9, stir for 2 hours, then slowly add deionized water, continue stirring for 40-60 minutes, let stand for 24 hours, filter the solid product, calcine at 350°C under a nitrogen atmosphere for 2 hours, and cool naturally to obtain modified sepiolite powder.

[0008] Preferably, in step (3), the Ag in the composite metal ion solution + Cu 2+ La 3+The molar ratio is (1-5):(5-10):(0.5-1).

[0009] Preferably, in step (4), the solid-liquid ratio of the product obtained in step (3) to the mixed solution is 1g:20mL; and the molar ratio of tetraethyl orthosilicate to deionized water is 1:2.

[0010] Preferably, the graphene-modified nano-titanium dioxide is prepared by the following method: Step 1: Mix acetic acid and anhydrous ethanol at a volume ratio of 1:10 to obtain solution A; dissolve titanium tetraisopropoxide in anhydrous ethanol at a volume ratio of 1:10 and stir to obtain solution B; dissolve tantalum ethoxide in anhydrous ethanol at a mass ratio of 1:10 and stir to obtain solution C; dissolve ferric nitrate nonahydrate and urea in deionized water at a mass ratio and stir to obtain solution D. Step 2: Slowly add solution C to solution B and stir at room temperature for 30 minutes to obtain mixture M; then add solution A to mixture M at a volume ratio of 1:1 and stir at room temperature for 3 hours to obtain mixture N; Step 3: Add solution D and concentrated nitric acid to mixture N, stir at room temperature for 3 hours to obtain mixture Q; the volume ratio of solution D, mixture N and concentrated nitric acid is 1:4:(0.005-0.006). Step 4: Disperse graphene in anhydrous ethanol and sonicate for 0.5-2 hours to obtain a graphene dispersion; add the graphene dispersion to the mixture Q, stir evenly, and age under light-protected conditions for 24 hours to obtain a gel solution, and then freeze-dry it under vacuum to obtain graphene composite modified nano titanium dioxide.

[0011] Preferably, in step one, the molar ratio of tantalum ethoxide to titanium tetraisopropoxide is (0.005-0.03):1; and the mass ratio of ferric nitrate nonahydrate, urea, and deionized water is 1:1:(100-150).

[0012] Preferably, in step four, the mass ratio of graphene to titanium tetraisopropoxide is (0.005-0.015):1; and the concentration of the graphene dispersion is 0.5-2.0 mg / mL.

[0013] Preferably, the base glaze comprises, by weight: 48-52 parts quartz powder, 16-20 parts boric acid, 12-16 parts albite, 6-10 parts spodumene, 4-6 parts kaolin, and 2-4 parts zinc oxide; the base glaze is pre-melted at 1200-1250℃, then water-quenched and ball-milled to D50≤3.0μm.

[0014] Preferably, the transparent protective glaze layer is made from the following raw materials in parts by weight: 70-80 parts lead-free transparent frit, 5-10 parts nano alumina, 8-12 parts kaolin, 0.2-0.5 parts sodium carboxymethyl cellulose, and 20-30 parts deionized water.

[0015] This invention also provides a method for preparing the above-mentioned long-lasting antibacterial and easy-to-clean daily-use ceramic material, comprising the following steps: S1. Green body preparation: Weigh the green body raw materials according to the proportion, wet ball mill for 12-16 hours, pass through a 200-mesh sieve to obtain green body slurry, shape to prepare ceramic green body, air dry and then dry at 110-130℃ for 4-6 hours to obtain dry green body; S2. Preparation and application of the base glaze: Weigh the base glaze raw materials according to the formula, wet ball mill for 8-10 hours, pass through a 300-mesh sieve, and adjust the specific gravity of the glaze slurry to 1.45-1.55 g / cm³. 3 Spray the glaze onto the surface of the dried body, control the dry film thickness of the base glaze layer to be 0.10-0.30 mm, and dry at 90-100℃ for 2-3 hours to obtain the base glaze body; S3. Preparation of Functional Glaze: Graphene-modified nano-titanium dioxide was prepared, then mixed with base glaze, dispersant, flux, and deionized water and ball-milled for 6-8 hours. The mixture was then passed through a 400-mesh sieve, and the glaze slurry specific gravity was adjusted to 1.38-1.48 g / cm³. 3 A functional glaze slurry is obtained; the dispersant is sodium hexametaphosphate and the flux is zirconium oxide. S4. Secondary glazing: The functional surface glaze is sprayed onto the surface of the base glaze body, and the dry film thickness of the functional surface glaze layer is controlled to be 0.05-0.15 mm. It is then dried at 85-95℃ for 1.5-2.5 hours to obtain the ceramic blank. S5. Preparation and Glazing of Protective Layer: Weigh the protective layer raw materials according to the formula, wet ball mill for 6-8 hours, pass through a 400-mesh sieve, and adjust the specific gravity of the glaze slurry to 1.30-1.40 g / cm³. 3 The protective glaze slurry is sprayed onto the surface of the functional surface glaze layer, and the thickness of the transparent protective layer dry film is controlled to be 5-15μm. After drying at 85-95℃ for 1.5-2.5h, a ceramic blank with a transparent protective layer is obtained. S6. Gradient in-situ sintering: The ceramic blank is sintered in stages with a gradient heating. The first stage is heated from room temperature to 550℃ at a rate of 5℃ / min and held for 30 min. The second stage is heated from 550℃ to 950℃ at a rate of 8℃ / min and held for 20 min. The third stage is heated from 950℃ to 1220-1240℃ at a rate of 6℃ / min and held for 5-8 min. After sintering, the blank is naturally cooled to room temperature in the kiln to obtain a long-lasting antibacterial and easy-to-clean daily ceramic material.

[0016] Compared with the prior art, the beneficial effects of the present invention are: (1) Silver / copper / rare earth modified sepiolite powder encapsulated in nano-silica is introduced into the ceramic body as a composite antibacterial component. The modified sepiolite powder is encapsulated in nano-SiO2 and loaded with Ag. + / Cu 2+ / La 3+ During material use, ternary metal ions slowly and continuously release antibacterial ions through mesoporous channels. Even under light-free conditions (such as at night, on cloudy days, or when stored in a cabinet), they maintain a stable antibacterial effect, providing basic antibacterial protection around the clock. Simultaneously, the graphene-modified nano-titanium dioxide in the glaze layer can be excited under visible light or even low light conditions, generating hydroxyl radicals (·OH) and superoxide anions (·O2). - Photocatalytic oxidation directly attacks bacterial cell membranes and disrupts intracellular enzyme systems, achieving highly efficient sterilization. Furthermore, this photocatalytic process is not limited by the intermediate step of pollutant decomposition, resulting in a more direct and rapid bactericidal effect. Under light conditions, the reactive oxygen species generated by the photocatalytic reaction weaken the bacterial cell wall structure, thus inhibiting the subsequent release of Ag. + / Cu 2+ It penetrates more easily into the interior of bacteria, significantly improving the efficiency of ion sterilization. Simultaneously, the photocatalytic reaction consumes organic matter and generates a superhydrophilic surface, reducing initial bacterial adhesion and biofilm formation on the glaze surface. This allows antibacterial ions to more easily contact planktonic bacteria, further enhancing the sterilization effect. In the dark, the slow-release ions continuously replenish the antibacterial capacity, compensating for the gap after the photocatalytic reaction stops. Both work together to provide all-day coverage with enhanced sterilization under light and continuous antibacterial action in the dark, resulting in significantly better antibacterial performance than a single antibacterial system. Furthermore, the photocatalytic reaction endows the glaze surface with durable superhydrophilic properties, making it difficult for dirt and scale to adhere firmly. Combined with the physical protection of the transparent protective layer, easy cleaning and antibacterial performance coexist synergistically, without relying on coating peeling.

[0017] (2) The present invention uses the base glaze layer as a transition layer and adopts a gradient matching design of thermal expansion coefficient to effectively eliminate the internal stress of the multi-layer structure during high-temperature sintering and avoid defects such as glaze cracking and peeling; the graphene composite modified nano titanium dioxide in the functional surface glaze layer is evenly dispersed and the particle size is controllable, and it does not agglomerate or crystallize in the glaze layer, ensuring that the glaze surface is transparent and smooth; the transparent protective layer introduces nano alumina reinforcing phase, which improves the surface hardness and wear resistance without affecting the light transmittance, so that the product has both excellent glaze quality and mechanical properties.

[0018] (3) The preparation process of this invention is simple and controllable, requiring no additional equipment modification. The entire process is completed in a conventional ceramic production line. Each layer of glaze slurry is prepared using mature wet ball milling and spraying processes in the ceramic field. Each functional layer can be completed by secondary glazing and one gradient sintering. The process window is wide, the parameters are highly controllable, and it is easy to achieve industrial continuous production on existing ceramic production lines with high mass production stability. Attached Figure Description

[0019] Figure 1 This is a SEM image of the cross-section of the ceramic sample obtained in Example 3 of the present invention. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to specific embodiments, but is not limited thereto. Unless otherwise specified, all raw materials used in the present invention are commercially available industrial-grade products.

[0021] Example 1 A long-lasting antibacterial and easy-to-clean daily ceramic material includes a ceramic body, a base glaze layer covering the surface of the ceramic body, a functional surface glaze layer covering the surface of the base glaze layer, and a transparent protective glaze layer covering the surface of the functional surface glaze layer.

[0022] The ceramic body is made from the following raw materials by weight (kg): 45 kg kaolin, 28 kg potassium feldspar, 12 kg quartz sand, 6 kg talc, 2 kg calcite, 10 kg modified sepiolite powder, and 30 kg deionized water.

[0023] The base glaze layer is made from the following raw materials by weight (kg): 35 kg of albite, 28 kg of quartz, 10 kg of calcined kaolin, 10 kg of wollastonite, 3 kg of zinc oxide, 12 kg of lead-free boron frit, and 25 kg of deionized water; the thickness of the base glaze layer is 0.10 mm.

[0024] The functional glaze layer is made from the following raw materials by weight (kg): 75 kg of base glaze, 10 kg of graphene composite modified nano titanium dioxide, 0.5 kg of sodium hexametaphosphate, 2 kg of zirconium oxide, and 18 kg of deionized water; the thickness of the functional glaze layer is 0.15 mm.

[0025] The transparent protective glaze is made from the following raw materials by weight (kg): 70 kg of lead-free transparent frit, 10 kg of nano alumina, 8 kg of kaolin, 0.5 kg of sodium carboxymethyl cellulose, and 20 kg of deionized water; the thickness of the transparent protective glaze is 15 μm.

[0026] The modified sepiolite powder is prepared by the following method: (1) Crush natural sepiolite powder through a 200-mesh sieve, then immerse it in 0.1 mol / L hydrochloric acid solution at a solid-liquid ratio of 1 g: 10 mL, microwave for 10 min, filter and wash until neutral, and dry. (2) Place the product obtained in step (1) in a muffle furnace, heat it to 200℃ at 2℃ / min and hold it for 60min; then heat it to 350℃ at 3℃ / min and hold it for 90min; finally heat it to 450℃ at 1℃ / min and hold it for 120min. After cooling to room temperature, grind it to obtain calcined sepiolite powder. (3) Calcined sepiolite powder was immersed in a composite metal ion solution at a solid-liquid ratio of 1g:15mL, stirred at 70℃ for 6h, filtered, washed three times with deionized water, and dried; Ag in the composite metal ion solution + Cu 2+ La 3+ The molar ratio is 1:10:0.5; (4) Disperse the product obtained in step (3) in a mixed solution of tetraethyl orthosilicate and anhydrous ethanol in a volume ratio of 1:5 at a solid-liquid ratio of 1g:20mL. Add ammonia to adjust the pH of the system to 8. Stir for 2 hours and then slowly add deionized water. Continue stirring for 40 minutes and let stand for 24 hours. After filtration, calcine the solid product at 350℃ under a nitrogen atmosphere for 2 hours and cool naturally to obtain modified sepiolite powder. The molar ratio of tetraethyl orthosilicate to deionized water is 1:2.

[0027] The graphene-modified nano-titanium dioxide was prepared using the following method: Step 1: Mix acetic acid and anhydrous ethanol at a volume ratio of 1:10 and stir until homogeneous to obtain solution A; dissolve tetraisopropoxide titanium in anhydrous ethanol at a volume ratio of 1:10 and stir until homogeneous to obtain solution B; dissolve tantalum ethoxide in anhydrous ethanol at a mass ratio of 1:10 and stir until homogeneous to obtain solution C; dissolve ferric nitrate nonahydrate and urea in deionized water at a mass ratio of 1:1 and stir until homogeneous to obtain solution D, wherein the mass ratio of ferric nitrate nonahydrate to deionized water is 1:100. Step 2: Slowly add solution C to solution B at a dropping rate of 2 mL / min, stir at room temperature for 30 min to obtain mixture M; then add solution A to mixture M at a volume ratio of 1:1, continue stirring at room temperature for 3 hours to obtain mixture N; wherein, the molar ratio of tantalum ethoxide to titanium tetraisopropoxide is 0.005:1; Step 3: Add solution D and concentrated nitric acid to mixture N, stir at room temperature for 3 hours to obtain mixture Q; the volume ratio of solution D, mixture N and concentrated nitric acid is 1:4:0.005; Step 4: Graphene is dispersed in anhydrous ethanol and ultrasonically treated for 0.5 h to obtain a graphene dispersion (concentration of 0.5 mg / mL); the graphene dispersion is added to the mixture Q, stirred evenly, and aged under light-protected conditions for 24 hours to obtain a gel solution, which is then freeze-dried under vacuum to obtain graphene composite modified nano-titanium dioxide; wherein the mass ratio of graphene to tetraisopropoxide titanium is 0.005:1.

[0028] The base glaze comprises, by weight (kg): 48 kg of quartz powder, 20 kg of boric acid, 12 kg of sodium feldspar, 10 kg of spodumene, 4 kg of kaolin, and 4 kg of zinc oxide; the base glaze is pre-melted at 1200℃, then water-quenched and ball-milled to D50≤3.0μm.

[0029] The preparation method of the above-mentioned long-lasting antibacterial and easy-to-clean daily ceramic material includes the following steps: S1. Preparation of green body: Weigh the green body raw materials according to the proportion, wet ball mill for 12 hours, pass through a 200-mesh sieve to obtain green body slurry, shape to prepare ceramic green body, air dry and then dry at 110℃ for 6 hours to obtain dry green body; S2. Preparation and application of the base glaze: Weigh the base glaze raw materials according to the formula, wet ball mill for 8 hours, pass through a 300-mesh sieve, and adjust the specific gravity of the glaze slurry to 1.45 g / cm³. 3 The glaze is sprayed onto the surface of the dried body, and the dry film thickness of the base glaze layer is controlled to be 0.10 mm. It is then dried at 90℃ for 3 hours to obtain the base glaze body. S3. Preparation of Functional Glaze: Graphene-modified nano-titanium dioxide was prepared, then mixed with base glaze, sodium hexametaphosphate, zirconium oxide, and deionized water and ball-milled for 6 hours. The mixture was then passed through a 400-mesh sieve, and the specific gravity of the glaze slurry was adjusted to 1.38 g / cm³. 3 This yields a functional glaze paste. S4. Secondary glazing: The functional surface glaze is sprayed onto the surface of the base glaze body, and the dry film thickness of the functional surface glaze layer is controlled to be 0.15 mm. It is then dried at 85℃ for 2.5 h to obtain the ceramic blank. S5. Preparation and Glazing of Protective Layer: Weigh the protective layer raw materials according to the formula, wet ball mill for 6 hours, pass through a 400-mesh sieve, and adjust the specific gravity of the glaze slurry to 1.30 g / cm³. 3 The protective glaze slurry was sprayed onto the surface of the functional surface glaze layer, and the thickness of the transparent protective layer dry film was controlled to be 15 μm. After drying at 85℃ for 2.5h, a ceramic blank with a transparent protective layer was obtained. S6. Gradient in-situ sintering: The ceramic blank is sintered in stages with a gradient heating. The first stage is heated from room temperature to 550℃ at a rate of 5℃ / min and held for 30 min. The second stage is heated from 550℃ to 950℃ at a rate of 8℃ / min and held for 20 min. The third stage is heated from 950℃ to 1220℃ at a rate of 6℃ / min and held for 8 min. After sintering, the blank is naturally cooled to room temperature in the kiln to obtain a long-lasting antibacterial and easy-to-clean daily ceramic material.

[0030] Example 2 A long-lasting antibacterial and easy-to-clean daily ceramic material includes a ceramic body, a base glaze layer covering the surface of the ceramic body, a functional surface glaze layer covering the surface of the base glaze layer, and a transparent protective glaze layer covering the surface of the functional surface glaze layer.

[0031] The ceramic body is made from the following raw materials by weight (kg): 55 kg kaolin, 20 kg potassium feldspar, 18 kg quartz sand, 3 kg talc, 4 kg calcite, 5 kg modified sepiolite powder, and 40 kg deionized water.

[0032] The base glaze layer is made from the following raw materials by weight (kg): 42 kg of albite, 22 kg of quartz, 15 kg of calcined kaolin, 6 kg of wollastonite, 5 kg of zinc oxide, 8 kg of lead-free boron frit, and 32 kg of deionized water; the thickness of the base glaze layer is 0.30 mm.

[0033] The functional glaze layer is made from the following raw materials by weight (kg): 85 kg of base glaze, 6 kg of graphene composite modified nano titanium dioxide, 1.2 kg of sodium hexametaphosphate, 1 kg of zirconium oxide, and 25 kg of deionized water; the thickness of the functional glaze layer is 0.05 mm.

[0034] The transparent protective glaze is made from the following raw materials by weight (kg): 80 kg of lead-free transparent frit, 5 kg of nano alumina, 12 kg of kaolin, 0.2 kg of sodium carboxymethyl cellulose, and 30 kg of deionized water; the thickness of the transparent protective glaze is 5 μm.

[0035] The modified sepiolite powder is prepared by the following method: (1) Crush natural sepiolite powder through a 200-mesh sieve, then immerse it in 0.1 mol / L hydrochloric acid solution at a solid-liquid ratio of 1 g: 10 mL, microwave for 15 min, filter and wash until neutral, and dry. (2) Place the product obtained in step (1) in a muffle furnace, heat it to 200℃ at 2℃ / min and hold it for 60min; then heat it to 350℃ at 3℃ / min and hold it for 90min; finally heat it to 450℃ at 1℃ / min and hold it for 120min. After cooling to room temperature, grind it to obtain calcined sepiolite powder. (3) Calcined sepiolite powder was immersed in a composite metal ion solution at a solid-liquid ratio of 1g:15mL, stirred at 75℃ for 5h, filtered, washed 5 times with deionized water, and dried; Ag in the composite metal ion solution + Cu 2+ La 3+ The molar ratio is 5:5:1; (4) Disperse the product obtained in step (3) in a mixed solution of tetraethyl orthosilicate and anhydrous ethanol in a volume ratio of 1:5 at a solid-liquid ratio of 1g:20mL. Add ammonia to adjust the pH of the system to 9. Stir for 2 hours and then slowly add deionized water. Continue stirring for 60 minutes and let stand for 24 hours. After filtration, calcine the solid product at 350℃ under a nitrogen atmosphere for 2 hours and cool naturally to obtain modified sepiolite powder. The molar ratio of tetraethyl orthosilicate to deionized water is 1:2.

[0036] The graphene-modified nano-titanium dioxide was prepared using the following method: Step 1: Mix acetic acid and anhydrous ethanol at a volume ratio of 1:10 and stir until homogeneous to obtain solution A; dissolve tetraisopropoxide titanium in anhydrous ethanol at a volume ratio of 1:10 and stir until homogeneous to obtain solution B; dissolve tantalum ethoxide in anhydrous ethanol at a mass ratio of 1:10 and stir until homogeneous to obtain solution C; dissolve ferric nitrate nonahydrate and urea in deionized water at a mass ratio of 1:1 and stir until homogeneous to obtain solution D, wherein the mass ratio of ferric nitrate nonahydrate to deionized water is 1:150. Step 2: Slowly add solution C to solution B at a dropping rate of 1 mL / min and stir at room temperature for 30 min to obtain mixture M; then add solution A to mixture M at a volume ratio of 1:1 and continue stirring at room temperature for 3 hours to obtain mixture N; wherein, the molar ratio of tantalum ethoxide to titanium tetraisopropoxide is 0.03:1; Step 3: Add solution D and concentrated nitric acid to mixture N, stir at room temperature for 3 hours to obtain mixture Q; the volume ratio of solution D, mixture N and concentrated nitric acid is 1:4:0.006; Step 4: Graphene is dispersed in anhydrous ethanol and ultrasonically treated for 2 hours to obtain a graphene dispersion (concentration of 2.0 mg / mL); the graphene dispersion is added to the mixture Q, stirred evenly, and aged under light-protected conditions for 24 hours to obtain a gel solution, which is then freeze-dried under vacuum to obtain graphene composite modified nano-titanium dioxide; wherein the mass ratio of graphene to tetraisopropoxide titanium is 0.015:1.

[0037] The base glaze comprises, by weight (kg): 52 kg of quartz powder, 16 kg of boric acid, 16 kg of albite, 6 kg of spodumene, 6 kg of kaolin, and 2 kg of zinc oxide; the base glaze is pre-melted at 1250℃, then water-quenched and ball-milled to D50≤3.0μm.

[0038] The preparation method of the above-mentioned long-lasting antibacterial and easy-to-clean daily ceramic material includes the following steps: S1. Green body preparation: Weigh the green body raw materials according to the proportion, wet ball mill for 16 hours, pass through a 200-mesh sieve to obtain green body slurry, shape to prepare ceramic green body, air dry and then dry at 130℃ for 4 hours to obtain dry green body; S2. Preparation and application of the base glaze: Weigh the base glaze raw materials according to the formula, wet ball mill for 10 hours, pass through a 300-mesh sieve, and adjust the specific gravity of the glaze slurry to 1.55 g / cm³. 3 The glaze is sprayed onto the surface of the dried body, and the dry film thickness of the base glaze layer is controlled to be 0.30 mm. It is then dried at 100℃ for 2 hours to obtain the base glaze body. S3. Preparation of Functional Glaze: Graphene-modified nano-titanium dioxide was prepared, then mixed with base glaze, sodium hexametaphosphate, zirconium oxide, and deionized water and ball-milled for 8 hours. The mixture was then passed through a 400-mesh sieve, and the specific gravity of the glaze slurry was adjusted to 1.48 g / cm³. 3 This yields a functional glaze paste. S4. Secondary glazing: The functional surface glaze is sprayed onto the surface of the base glaze body, and the dry film thickness of the functional surface glaze layer is controlled to be 0.05 mm. It is then dried at 95℃ for 1.5 h to obtain the ceramic blank. S5. Preparation and Glazing of Protective Layer: Weigh the protective layer raw materials according to the formula, wet ball mill for 8 hours, pass through a 400-mesh sieve, and adjust the specific gravity of the glaze slurry to 1.40 g / cm³. 3 The protective glaze slurry is sprayed onto the surface of the functional glaze layer, and the thickness of the transparent protective layer dry film is controlled to be 5μm. After drying at 95℃ for 1.5h, a ceramic blank with a transparent protective layer is obtained. S6. Gradient in-situ sintering: The ceramic blank is sintered in stages with a gradient heating. The first stage is heated from room temperature to 550℃ at a rate of 5℃ / min and held for 30 min. The second stage is heated from 550℃ to 950℃ at a rate of 8℃ / min and held for 20 min. The third stage is heated from 950℃ to 1240℃ at a rate of 6℃ / min and held for 5 min. After sintering, the blank is naturally cooled to room temperature in the kiln to obtain a long-lasting antibacterial and easy-to-clean daily ceramic material.

[0039] Example 3 A long-lasting antibacterial and easy-to-clean daily ceramic material includes a ceramic body, a base glaze layer covering the surface of the ceramic body, a functional surface glaze layer covering the surface of the base glaze layer, and a transparent protective glaze layer covering the surface of the functional surface glaze layer.

[0040] The ceramic body is made from the following raw materials by weight (kg): 50 kg kaolin, 24 kg potassium feldspar, 15 kg quartz sand, 4.5 kg talc, 3 kg calcite, 7.5 kg modified sepiolite powder, and 35 kg deionized water.

[0041] The base glaze layer is made from the following raw materials by weight (kg): 38.5 kg of albite, 25 kg of quartz, 12.5 kg of calcined kaolin, 8 kg of wollastonite, 4 kg of zinc oxide, 10 kg of lead-free boron frit, and 28.5 kg of deionized water; the thickness of the base glaze layer is 0.20 mm.

[0042] The functional glaze layer is made from the following raw materials by weight (kg): 80 kg of base glaze, 8 kg of graphene composite modified nano titanium dioxide, 0.85 kg of sodium hexametaphosphate, 1.5 kg of zirconium oxide, and 21.5 kg of deionized water; the thickness of the functional glaze layer is 0.10 mm.

[0043] The transparent protective glaze is made from the following raw materials by weight (kg): 75 kg of lead-free transparent frit, 7.5 kg of nano alumina, 10 kg of kaolin, 0.35 kg of sodium carboxymethyl cellulose, and 25 kg of deionized water; the thickness of the transparent protective glaze is 10 μm.

[0044] The modified sepiolite powder is prepared by the following method: (1) Crush natural sepiolite powder through a 200-mesh sieve, then immerse it in 0.1 mol / L hydrochloric acid solution at a solid-liquid ratio of 1 g: 10 mL, microwave for 12 min, filter and wash until neutral, and dry. (2) Place the product obtained in step (1) in a muffle furnace, heat it to 200℃ at 2℃ / min and hold it for 60min; then heat it to 350℃ at 3℃ / min and hold it for 90min; finally heat it to 450℃ at 1℃ / min and hold it for 120min. After cooling to room temperature, grind it to obtain calcined sepiolite powder. (3) Calcined sepiolite powder was immersed in a composite metal ion solution at a solid-liquid ratio of 1g:15mL, stirred at 72℃ for 5.5h, filtered, washed 4 times with deionized water, and dried; Ag in the composite metal ion solution + Cu 2+ La 3+ The molar ratio is 3:7.5:0.75; (4) Disperse the product obtained in step (3) in a mixed solution of tetraethyl orthosilicate and anhydrous ethanol in a volume ratio of 1:5 at a solid-liquid ratio of 1g:20mL. Add ammonia to adjust the pH of the system to 8.5. Stir for 2 hours and then slowly add deionized water. Continue stirring for 50 minutes and let stand for 24 hours. After filtration, calcine the solid product at 350℃ under a nitrogen atmosphere for 2 hours and cool naturally to obtain modified sepiolite powder. The molar ratio of tetraethyl orthosilicate to deionized water is 1:2.

[0045] The graphene-modified nano-titanium dioxide was prepared using the following method: Step 1: Mix acetic acid and anhydrous ethanol at a volume ratio of 1:10 and stir until homogeneous to obtain solution A; dissolve tetraisopropoxide titanium in anhydrous ethanol at a volume ratio of 1:10 and stir until homogeneous to obtain solution B; dissolve tantalum ethoxide in anhydrous ethanol at a mass ratio of 1:10 and stir until homogeneous to obtain solution C; dissolve ferric nitrate nonahydrate and urea in deionized water at a mass ratio of 1:1 and stir until homogeneous to obtain solution D, wherein the mass ratio of ferric nitrate nonahydrate to deionized water is 1:130. Step 2: Slowly add solution C to solution B at a dropping rate of 1.5 mL / min and stir at room temperature for 30 min to obtain mixture M; then add solution A to mixture M at a volume ratio of 1:1 and continue stirring at room temperature for 3 hours to obtain mixture N; wherein, the molar ratio of tantalum ethoxide to titanium tetraisopropoxide is 0.015:1. Step 3: Add solution D and concentrated nitric acid to mixture N, stir at room temperature for 3 hours to obtain mixture Q; the volume ratio of solution D, mixture N and concentrated nitric acid is 1:4:0.0055; Step 4: Graphene is dispersed in anhydrous ethanol and ultrasonically treated for 1.25 h to obtain a graphene dispersion (concentration of 1.25 mg / mL); the graphene dispersion is added to the mixture Q, stirred evenly, and aged under light-protected conditions for 24 hours to obtain a gel solution, which is then freeze-dried under vacuum to obtain graphene composite modified nano-titanium dioxide; wherein the mass ratio of graphene to tetraisopropoxide titanium is 0.01:1.

[0046] The base glaze comprises, by weight (kg): 50 kg of quartz powder, 18 kg of boric acid, 14 kg of sodium feldspar, 8 kg of spodumene, 5 kg of kaolin, and 3 kg of zinc oxide; the base glaze is pre-melted at 1225℃, then water-quenched and ball-milled to D50≤3.0μm.

[0047] The preparation method of the above-mentioned long-lasting antibacterial and easy-to-clean daily ceramic material includes the following steps: S1. Green body preparation: Weigh the green body raw materials according to the proportion, wet ball mill for 14 hours, pass through a 200-mesh sieve to obtain green body slurry, shape to prepare ceramic green body, air dry and then dry at 120℃ for 5 hours to obtain dry green body; S2. Preparation and application of the base glaze: Weigh the base glaze raw materials according to the formula, wet ball mill for 9 hours, pass through a 300-mesh sieve, and adjust the specific gravity of the glaze slurry to 1.50 g / cm³. 3 The glaze is sprayed onto the surface of the dried body, and the dry film thickness of the base glaze layer is controlled to be 0.20 mm. It is then dried at 95℃ for 2.5 h to obtain the base glaze body. S3. Preparation of Functional Glaze: Graphene-modified nano-titanium dioxide was prepared, then mixed with base glaze, sodium hexametaphosphate, zirconium oxide, and deionized water and ball-milled for 7 hours. The mixture was then passed through a 400-mesh sieve, and the specific gravity of the glaze slurry was adjusted to 1.43 g / cm³. 3 This yields a functional glaze paste. S4. Secondary glazing: The functional surface glaze is sprayed onto the surface of the base glaze body, and the dry film thickness of the functional surface glaze layer is controlled to be 0.10 mm. It is dried at 90℃ for 2 hours to obtain the ceramic blank. S5. Preparation and Glazing of Protective Layer: Weigh the protective layer raw materials according to the formula, wet ball mill for 7 hours, pass through a 400-mesh sieve, and adjust the specific gravity of the glaze slurry to 1.35 g / cm³. 3 The protective glaze slurry is sprayed onto the surface of the functional glaze layer, and the thickness of the transparent protective layer dry film is controlled to be 10 μm. After drying at 90℃ for 2 hours, a ceramic blank with a transparent protective layer is obtained. S6. Gradient in-situ sintering: The ceramic blank is sintered in stages with a gradient heating. The first stage is heated from room temperature to 550℃ at a rate of 5℃ / min and held for 30 min. The second stage is heated from 550℃ to 950℃ at a rate of 8℃ / min and held for 20 min. The third stage is heated from 950℃ to 1230℃ at a rate of 6℃ / min and held for 6.5 min. After sintering, the blank is naturally cooled to room temperature in the kiln to obtain a long-lasting antibacterial and easy-to-clean daily ceramic material.

[0048] Comparative Example 1 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that ordinary sepiolite powder is used instead of modified sepiolite powder in the ceramic body.

[0049] Specifically, the ceramic body is made from the following raw materials by weight (kg): 50 kg kaolin, 24 kg potassium feldspar, 15 kg quartz sand, 4.5 kg talc, 3 kg calcite, 7.5 kg sepiolite powder, and 35 kg deionized water. The composition of the remaining layers, the preparation method and process of the graphene composite modified nano-titanium dioxide in the functional glaze layer are exactly the same as in Example 3.

[0050] Comparative Example 2 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material. The difference between this material and Example 3 is that antibacterial sepiolite powder is used instead of modified sepiolite powder in the ceramic body. The preparation methods and processes of the remaining layers, the graphene composite modified nano-titanium dioxide in the functional glaze layer, are completely the same as in Example 3.

[0051] The specific preparation method of the antibacterial sepiolite powder is as follows: Natural sepiolite powder is pulverized and passed through a 200-mesh sieve. Then, it is immersed in a composite metal ion solution at a solid-liquid ratio of 1g:15mL, stirred at 72℃ for 5.5h, filtered, washed four times with deionized water, and dried to obtain the final product. The composite metal ion solution contains Ag... + Cu 2+ La 3+ The molar ratio is 3:7.5:0.75.

[0052] Comparative Example 3 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that: in the preparation process of the modified sepiolite powder, the composite metal ion solution in step (3) contains only Ag. + and La 3+ Cu-free 2+ Specifically, in step (3), calcined sepiolite powder is immersed in a composite metal ion solution at a solid-liquid ratio of 1g:15mL (Ag in the composite metal ion solution). + La 3+ The molar ratio of the materials was 3:0.75. The mixture was stirred at 72°C for 5.5 hours, filtered, washed four times with deionized water, and dried. The remaining preparation steps and material composition were exactly the same as in Example 3.

[0053] Comparative Example 4 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that: in the preparation process of the modified sepiolite powder, the composite metal ion solution in step (3) contains only Ag. + and Cu 2+ La-free 3+ Specifically, in step (3), calcined sepiolite powder is immersed in a composite metal ion solution at a solid-liquid ratio of 1g:15mL (Ag in the composite metal ion solution). + Cu 2+ The molar ratio was 3:7.5, and the mixture was stirred at 72°C for 5.5 hours, filtered, washed four times with deionized water, and dried. The remaining preparation steps and material composition were exactly the same as in Example 3.

[0054] Comparative Example 5 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that: in the preparation process of the modified sepiolite powder, the composite metal ion solution in step (3) contains only La. 3+ and Cu 2+ Ag-free + Specifically, in step (3), calcined sepiolite powder is immersed in a composite metal ion solution at a solid-liquid ratio of 1g:15mL (Cu in the composite metal ion solution) 2+ La 3+ The molar ratio of the materials was 7.5:0.75. The mixture was stirred at 72°C for 5.5 hours, filtered, washed four times with deionized water, and dried. The remaining preparation steps and material composition were exactly the same as in Example 3.

[0055] Comparative Example 6 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that: the functional surface glaze layer does not contain graphene composite modified nano titanium dioxide, but is replaced by an equal amount of ordinary nano titanium dioxide.

[0056] Comparative Example 7 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that: in the preparation process of the graphene composite modified nano titanium dioxide, tantalum ethoxide, ferric nitrate nonahydrate, and urea were not added in step one.

[0057] Comparative Example 8 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that: in the preparation process of the graphene composite modified nano titanium dioxide, no graphene was added in step two (i.e., no graphene composite was performed).

[0058] Comparative Example 9 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that: in the preparation process of the graphene composite modified nano titanium dioxide, ferric nitrate nonahydrate (i.e., Ta-N binary co-doping, lacking Fe) was not added.

[0059] Comparative Example 10 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that: during the preparation of the graphene composite modified nano titanium dioxide, urea was not added (i.e., Ta-Fe binary co-doping, lacking N).

[0060] Comparative Example 11 This comparative example provides a long-lasting antibacterial and easy-to-clean daily ceramic material, which differs from Example 3 in that: in the preparation process of the graphene composite modified nano titanium dioxide, tantalum ethoxide (i.e., Fe-N binary co-doping, lacking Ta) was not added.

[0061] Performance testing Ceramic samples prepared in Examples 1-3 and Comparative Examples 1-11 were selected and uniformly cut into 50mm×50mm standard test pieces. Mechanical properties, antibacterial properties, and easy-to-clean and durable properties were tested respectively. Five test pieces were tested in parallel for each group of samples, and the average value was taken as the final test result.

[0062] Test Example 1: Long-lasting antibacterial performance test According to JC / T 897-2014 "Antibacterial Properties of Antibacterial Ceramic Products" standard, the antibacterial rate of samples from Examples 1-3 and Comparative Examples 1-11 was tested after 24 hours. The antibacterial rate of samples after 200 standard dishwasher washes was also tested to evaluate their long-term stability. Simultaneously, to verify the antibacterial ability in the dark, the samples were placed in a completely dark environment for 24 hours before the antibacterial rate test. The tested bacteria were *Escherichia coli* (ATCC 25922) and *Staphylococcus aureus* (ATCC 6538). The results are shown in Table 1.

[0063] Table 1. Antibacterial performance test results As can be seen from the results in Table 1 above, the daily-use ceramic materials of Examples 1-3 of this invention all achieved an inhibition rate of over 99.98% against Escherichia coli and Staphylococcus aureus within 24 hours. After being placed in a completely dark environment for 24 hours, the inhibition rates against the two bacteria remained above 98.5% and 99.2%, respectively, proving that the Ag in the modified sepiolite powder in the body... + / Cu 2+ / La 3+ The ternary ion slow-release mechanism remains effective even under light-free conditions, compensating for the gap period after the photocatalytic reaction stops. After 200 standard washes, the antibacterial rate remains above 99.90%, indicating that the multi-layer glaze structure is stable, the functional layer is unaffected by physical wear, and the antibacterial durability is excellent. This fully demonstrates that the material of this invention possesses all-weather long-lasting antibacterial ability with enhanced sterilization under light and continuous antibacterial activity in the dark. Comparative Example 1 uses unmodified ordinary sepiolite powder in the body, lacking long-lasting slow-release antibacterial ion ability, with a significant decrease in the initial antibacterial rate and severe attenuation after washing; Comparative Example 2, although loaded with metal ions, has not undergone nano-SiO2 encapsulation and gradient calcination treatment, resulting in poor ion slow-release effect and significantly inferior long-term stability compared to the examples; Comparative Examples 3-5 show that Ag + Cu 2+ La 3+ All three ions are indispensable: Cu is lacking. 2+ The comparative ratio 3 affected the broad-spectrum antibacterial activity; the lack of La 3+ Comparative Example 4 affected the ion co-release efficiency; lack of Ag +Comparative Example 5 showed a significant deterioration in antibacterial performance. Comparative Examples 6-8 indicated that the surface glaze did not use the graphene composite modified nano-titanium dioxide specific to this invention, or lacked graphene composite or co-doping modification, resulting in insufficient photocatalytic bactericidal ability. Consequently, antibacterial properties in the dark relied solely on ion slow release, leading to a significant decrease in overall antibacterial durability. Comparative Examples 9-11 confirmed that the ternary co-doping of Ta, Fe, and N is crucial for improving the photocatalytic bactericidal efficiency of TiO2, and the absence of any one element would lead to a significant reduction in performance.

[0064] Test Example 2: Results of Easy-to-Clean Performance Test According to the quantitative test method for easy cleaning of oil stains in GB / T 31859-2015 "Daily-use Porcelain", the easy-to-clean performance of samples from Examples 1-3 and Comparative Examples 1-11 was tested. The sample size was 100 cm. 2 A flat test piece was coated with a measured amount of edible salad oil and left to stand at room temperature for 24 hours. It was then rinsed with running water at room temperature for 1 minute, dried, and the residual oil was weighed. The amount of residual oil per unit area was calculated. Simultaneously, the ease of cleaning was compared after 200 wipes with a damp cloth, with the residual oil amount being ≤0.1 mg / cm³. 2 Excellent easy-to-clean properties (oil stains can be mostly rinsed away with water); 0.1-0.2 mg / cm³ 2 Good for easy cleaning; >0.2 mg / cm³ 2 It is not easy to clean. See Table 2 for specific results.

[0065] Table 2 Easy-clean performance test results As shown in Table 2, the residual oil content in Examples 1-3 of the present invention is all between 0.042 and 0.047 mg / cm³. 2 The concentration is significantly lower than the excellent easy-clean classification threshold (≤0.1 mg / cm³) in the GB / T 31859-2015 standard. 2 This indicates that rinsing with room temperature water is sufficient to remove most surface oil stains, without the need for detergent. After 200 wipes with a damp cloth, the residual oil concentration increased slightly but remained between 0.079 and 0.091 mg / cm³. 2The oil residue levels in Comparative Examples 1-5 are still within the excellent easy-clean range, demonstrating the excellent mechanical durability of the photocatalytic superhydrophilic surface. The oil residue levels in Comparative Examples 1-5 are essentially equivalent to those in Example 3, still within the excellent easy-clean range. This indicates that the modification method of the sepiolite powder in the body (whether it is loaded with metal ions, the type of ions, and the ratio) has no direct impact on the photocatalytic superhydrophilic performance of the glaze; the easy-clean function is mainly determined by the photocatalytic material in the glaze layer. Comparative Example 6, which uses ordinary nano-TiO2 instead of the graphene composite-modified nano-TiO2 of this invention, has an oil residue level as high as 0.255 mg / cm², far exceeding the excellent easy-clean threshold, and significant oil residue remains even after rinsing with water. Comparative Example 7 did not undergo any doping modification, and Comparative Example 8 lacked graphene composite; the oil residue levels were 0.181 mg / cm², respectively. 2 and 0.211 mg / cm 2 None of them achieved an excellent easy-clean rating. Comparative Examples 9-11 lacked Fe, N, and Ta elements, respectively, and their oil residue levels ranged from 0.194 to 0.201 mg / cm³. 2 Similarly, it was impossible to remove the oil stains with water alone, and after 200 wipes, the residual amount further increased to 0.312-0.325 mg / cm³. 2 The above comparative examples illustrate that the Ta-Fe-N ternary co-doped structure of graphene-modified nano-titanium dioxide and the graphene composite in this invention are the core technical means to impart efficient and long-lasting photocatalytic superhydrophilic properties to the glaze surface. Without any of the key components, the excellent easy-to-clean effect cannot be achieved.

[0066] Test Example 3: Mechanical Property Test Mechanical properties were tested on the samples from Examples 1-3 and Comparative Examples 1-11. The specific methods are as follows: Surface Vickers hardness: HV Vickers hardness tester, load 0.5kg, holding pressure for 10s, multiple points tested and averaged; Abrasion resistance: Abrasion tester, 1000 cycles of reciprocating friction with steel wool, compare the loss rate of glaze gloss before and after friction; Thermal stability performance: Cold and hot cycle test (immersion in boiling water at 80℃ for 5 minutes → sudden cooling in cold water at room temperature, cycled 50 times), observe whether the glaze cracks or peels. The test results are shown in Table 3.

[0067] Table 3 Mechanical Performance Test Results The results above show that Examples 1-3 of this invention exhibit excellent performance in Vickers hardness, wear resistance, and thermal stability. The mechanical properties of Comparative Examples 1-6 are essentially the same as those of the Examples, indicating that the body composition and the modification method of sepiolite powder have no direct impact on the mechanical properties of the glaze. Comparative Examples 7-11 showed varying degrees of decrease in hardness and wear resistance due to poor modification and dispersion of nano-TiO2 in the glaze, further demonstrating the crucial role of the fully modified graphene composite nano-titanium dioxide in ensuring the density and mechanical properties of the multilayer glaze structure.

[0068] It should be noted that the above embodiments are merely some preferred embodiments of the present invention, and not all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

Claims

1. A long-lasting antibacterial and easy-to-clean daily-use ceramic material, characterized in that, It includes a ceramic body, a base glaze layer covering the surface of the ceramic body, a functional surface glaze layer covering the surface of the base glaze layer, and a transparent protective glaze layer covering the surface of the functional surface glaze layer. The ceramic body is made from the following raw materials in parts by weight: 45-55 parts kaolin, 20-28 parts potassium feldspar, 12-18 parts quartz sand, 3-6 parts talc, 2-4 parts calcite, 5-10 parts modified sepiolite powder, and 30-40 parts deionized water. The base glaze layer is made from the following raw materials in parts by weight: 35-42 parts albite, 22-28 parts quartz, 10-15 parts calcined kaolin, 6-10 parts wollastonite, 3-5 parts zinc oxide, 8-12 parts lead-free boron frit, and 25-32 parts deionized water; the thickness of the base glaze layer is 0.10-0.30 mm. The functional glaze layer is made from the following raw materials in parts by weight: 75-85 parts of base glaze, 6-10 parts of graphene composite modified nano titanium dioxide, 0.5-1.2 parts of dispersant, 1-2 parts of flux, and 18-25 parts of deionized water; the thickness of the functional glaze layer is 0.05-0.15 mm; and the thickness of the transparent protective glaze layer is 5-15 μm.

2. The long-lasting antibacterial and easy-to-clean daily-use ceramic material according to claim 1, characterized in that, The modified sepiolite powder is prepared by the following method: (1) Crush natural sepiolite powder through a 200-mesh sieve, then immerse it in 0.1 mol / L hydrochloric acid solution at a solid-liquid ratio of 1 g: 10 mL, microwave it for 10-15 min, filter and wash it until neutral, and dry it. (2) Place the product obtained in step (1) in a muffle furnace, heat it to 200℃ at 2℃ / min and hold it for 60min; then heat it to 350℃ at 3℃ / min and hold it for 90min; finally heat it to 450℃ at 1℃ / min and hold it for 120min. After cooling to room temperature, grind it to obtain calcined sepiolite powder. (3) Immerse the calcined sepiolite powder in a composite metal ion solution at a solid-liquid ratio of 1g:15mL, stir at 70-75℃ for 5-6h, filter, wash with deionized water 3-5 times, and dry. (4) Disperse the product obtained in step (3) in a mixed solution of tetraethyl orthosilicate and anhydrous ethanol in a volume ratio of 1:5, add ammonia to adjust the pH of the system to 8-9, stir for 2 hours, then slowly add deionized water, continue stirring for 40-60 minutes, let stand for 24 hours, filter the solid product, calcine at 350°C under a nitrogen atmosphere for 2 hours, and cool naturally to obtain modified sepiolite powder.

3. The long-lasting antibacterial and easy-to-clean daily-use ceramic material according to claim 2, characterized in that, The molar ratio of Ag + , Cu 2+ , La 3+ in the complex metal ion solution in step (3) is (1-5):(5-10):(0.5-1).

4. The long-lasting antibacterial and easy-to-clean daily-use ceramic material according to claim 2, characterized in that, In step (4), the solid-liquid ratio of the product obtained in step (3) to the mixed solution is 1 g: 20 mL; the molar ratio of tetraethyl orthosilicate to deionized water is 1:

2.

5. The long-lasting antibacterial and easy-to-clean daily-use ceramic material according to claim 1, characterized in that, The graphene-modified nano-titanium dioxide was prepared using the following method: Step 1: Mix acetic acid and anhydrous ethanol at a volume ratio of 1:10 to obtain solution A; dissolve titanium tetraisopropoxide in anhydrous ethanol at a volume ratio of 1:10 and stir to obtain solution B; dissolve tantalum ethoxide in anhydrous ethanol at a mass ratio of 1:10 and stir to obtain solution C; dissolve ferric nitrate nonahydrate and urea in deionized water at a mass ratio and stir to obtain solution D. Step 2: Slowly add solution C to solution B and stir at room temperature for 30 minutes to obtain mixture M; then add solution A to mixture M at a volume ratio of 1:1 and stir at room temperature for 3 hours to obtain mixture N; Step 3: Add solution D and concentrated nitric acid to mixture N, stir at room temperature for 3 hours to obtain mixture Q; the volume ratio of solution D, mixture N and concentrated nitric acid is 1:4:(0.005-0.006). Step 4: Disperse graphene in anhydrous ethanol and sonicate for 0.5-2 hours to obtain a graphene dispersion; add the graphene dispersion to the mixture Q, stir evenly, and age under light-protected conditions for 24 hours to obtain a gel solution, and then freeze-dry it under vacuum to obtain graphene composite modified nano titanium dioxide.

6. The long-lasting antibacterial and easy-to-clean daily-use ceramic material according to claim 5, characterized in that, In step one, the molar ratio of tantalum ethoxide to titanium tetraisopropoxide is (0.005-0.03):1; the mass ratio of ferric nitrate nonahydrate, urea, and deionized water is 1:1:(100-150).

7. The long-lasting antibacterial and easy-to-clean daily-use ceramic material according to claim 5, characterized in that, In step four, the mass ratio of graphene to titanium tetraisopropoxide is (0.005-0.015):1; the concentration of the graphene dispersion is 0.5-2.0 mg / mL.

8. The long-lasting antibacterial and easy-to-clean daily-use ceramic material according to claim 1, characterized in that, The base glaze comprises, by weight, 48-52 parts quartz powder, 16-20 parts boric acid, 12-16 parts albite, 6-10 parts spodumene, 4-6 parts kaolin, and 2-4 parts zinc oxide; the base glaze is pre-melted at 1200-1250℃, then water-quenched and ball-milled to D50≤3.0μm.

9. The long-lasting antibacterial and easy-to-clean daily-use ceramic material according to claim 1, characterized in that, The transparent protective glaze is made from the following raw materials in parts by weight: 70-80 parts lead-free transparent frit, 5-10 parts nano alumina, 8-12 parts kaolin, 0.2-0.5 parts sodium carboxymethyl cellulose, and 20-30 parts deionized water.

10. A method for preparing a long-lasting antibacterial and easy-to-clean daily-use ceramic material according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Green body preparation: Weigh the green body raw materials according to the proportion, wet ball mill for 12-16 hours, pass through a 200-mesh sieve to obtain green body slurry, shape to prepare ceramic green body, air dry and then dry at 110-130℃ for 4-6 hours to obtain dry green body; S2, bottom glaze preparation and glazing: according to the proportion of bottom glaze raw materials, wet ball milling for 8-10h, passing through 300 mesh sieve, adjusting the specific gravity of glaze slurry to 1.45-1.55 g / cm 3 , spraying on the surface of the dry body, controlling the dry film thickness of the bottom glaze layer to be 0.10-0.30 mm, drying at 90-100℃ for 2-3h, obtaining a bottom glaze body; S3, functional surface glaze preparation: prepare graphene composite modified nano titanium dioxide, and then mix with base glaze, dispersing agent, fluxing agent and deionized water, ball mill for 6-8 h, pass through a 400 mesh screen, and adjust the glaze slurry specific gravity to 1.38-1.48 g / cm 3 , to obtain a functional surface glaze slurry; S4. Secondary glazing: The functional surface glaze is sprayed onto the surface of the base glaze body, and the dry film thickness of the functional surface glaze layer is controlled to be 0.05-0.15 mm. It is then dried at 85-95℃ for 1.5-2.5 hours to obtain the ceramic blank. S5. Preparation and Glazing of Protective Layer: Weigh the protective layer raw materials according to the formula, wet ball mill for 6-8 hours, pass through a 400-mesh sieve, and adjust the specific gravity of the glaze slurry to 1.30-1.40 g / cm³. 3 The protective glaze slurry is sprayed onto the surface of the functional surface glaze layer, and the thickness of the transparent protective layer dry film is controlled to be 5-15μm. After drying at 85-95℃ for 1.5-2.5h, a ceramic blank with a transparent protective layer is obtained. S6. Gradient in-situ sintering: The ceramic blank is sintered in stages with a gradient heating. The first stage is heated from room temperature to 550℃ at a rate of 5℃ / min and held for 30 min. The second stage is heated from 550℃ to 950℃ at a rate of 8℃ / min and held for 20 min. The third stage is heated from 950℃ to 1220-1240℃ at a rate of 6℃ / min and held for 5-8 min. After sintering, the blank is naturally cooled to room temperature in the kiln to obtain a long-lasting antibacterial and easy-to-clean daily ceramic material.

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