Long-acting antibacterial enamel, antibacterial ceramic preparation method and ceramic sanitary product

Abstract

The application discloses a long-acting antibacterial glaze, which comprises potassium feldspar 9-14%, quartz 28-35%, lithium low-expansion powder 11-16%, high-transparency clinker powder 15-22%, calcite 8-14%, calcined kaolin 6-11%, talc 4-8%, zinc oxide 0.5-2.5% and antibacterial powder 4-11% according to mass percentage. The application further discloses a preparation method of antibacterial ceramic using the long-acting antibacterial glaze. The method comprises the following steps: preparing a ceramic blank, performing high-pressure slip casting on the ceramic blank, drying the ceramic blank after demolding to obtain a green body; applying the antibacterial glaze on the surface of the green body to form an antibacterial glaze coating; drying the green body with the antibacterial glaze coating and then performing sintering in a kiln to obtain a ceramic sanitary product finished product with long-acting antibacterial function. The application further discloses a ceramic sanitary product prepared by the preparation method of antibacterial ceramic using the long-acting antibacterial glaze. Compared with the prior art, the technical scheme of the application has the advantages of long-acting antibacterial function, high strength and high transmittance, heat stability and adaptation, and the like, and can effectively improve the antibacterial performance of the glaze and the main surface of the ceramic sanitary product.

Description

Technical Field

[0001] This invention relates to the field of bathroom product technology, and in particular to a long-lasting antibacterial glaze, a method for preparing antibacterial ceramics, and ceramic bathroom products. Background Technology

[0002] With social development and the continuous improvement of people's living standards, people have higher demands for the health and safety of bathroom products. As bathroom products that people frequently come into contact with in their daily lives, the surface antibacterial function of ceramic bathroom products has become a key research direction in the industry. Currently, ceramic bathroom products mainly achieve antibacterial functions through two technical routes: one is to add silver-based antibacterial agents to the glaze, utilizing silver ions for sterilization; the other is to add photocatalytic materials, such as nano-titanium dioxide, to the glaze, which generate highly reactive oxidizing oxides under light conditions to kill bacteria.

[0003] However, existing sterilization technologies still have certain technical shortcomings. Since ceramic sanitary ware products are typically made of ceramic materials, the firing process involves high temperatures and long firing cycles. When applying silver-based antibacterial agents, the high firing temperature causes the agents to decompose, reducing silver ions to non-antibacterial elemental silver, thus lowering antibacterial performance. Furthermore, ceramic sanitary ware products are used in unique environments, often in complex conditions involving prolonged dampness, dirt contamination, and frequent cleaning with chemical detergents. In such environments, the surface antibacterial layer or glaze layer is prone to excessive leaching of antibacterial components or damage to the surface structure, leading to a rapid decline in antibacterial function. This makes it difficult for ceramic sanitary ware products to meet the required lifespan of several years or even decades.

[0004] Therefore, in view of the shortcomings of existing technologies, how to improve the efficiency and stability of antibacterial components during high-temperature and long-term firing, ensure the glaze layer has long-lasting and broad-spectrum antibacterial properties, and ensure that the glaze surface has high gloss, excellent wear resistance and chemical corrosion resistance, so that ceramic sanitary products still have excellent performance in practical applications. Summary of the Invention

[0005] The main objective of this invention is to propose a long-lasting antibacterial glaze, a method for preparing antibacterial ceramics, and ceramic sanitary ware products, aiming to improve the antibacterial properties of glazes and ceramic sanitary ware products during application.

[0006] To achieve the above objectives, the present invention proposes a long-lasting antibacterial glaze, which, by mass percentage, comprises 9-14% potassium feldspar, 28-35% quartz, 11-16% lithium low-expansion powder, 15-22% high-permeability frit powder, 8-14% calcite, 6-11% calcined kaolin, 4-8% talc, 0.5-2.5% zinc oxide, and 4-11% antibacterial powder.

[0007] Preferably, the high-permeability frit powder is calculated by mass percentage as follows: 58-62% silicon dioxide, 14-16% aluminum oxide, 6-8% calcium oxide, 2-4% magnesium oxide, 2-3% potassium oxide, 3-4% sodium oxide, and 3-4% zinc oxide.

[0008] Preferably, the antibacterial powder is a silver-loaded zirconium phosphate antibacterial agent, wherein the silver oxide loading is 1.0-5.0 wt%, the particle size D50 of the antibacterial powder is 1-10 μm, and the specific surface area is 5-15 m² / g.

[0009] This invention also proposes a method for preparing antibacterial ceramics using the aforementioned long-lasting antibacterial glaze, comprising the following steps: Step S1: Prepare ceramic blanks, perform high-pressure slip casting to form ceramic blanks, demold and dry them to obtain ceramic sanitary ware product blanks; Step S2: Apply long-lasting antibacterial glaze to the surface of the ceramic sanitary ware product body to form an antibacterial glaze coating; Step S3: After drying the ceramic sanitary ware body with the long-lasting antibacterial glaze coating, send it into the kiln for firing to obtain the finished ceramic sanitary ware body with long-lasting antibacterial function.

[0010] Preferably, in step S2, the long-lasting antibacterial glaze coating includes a bottom antibacterial-rich layer and a top transparent protective layer. The top transparent protective layer is applied on top of the bottom antibacterial-rich layer. The amount of antibacterial powder added to the bottom antibacterial-rich layer is 8-15%, and the glaze application amount is 250-300g / m². No antibacterial powder is added to the top transparent protective layer, and the glaze application amount is 150-200g / m².

[0011] Preferably, in step S3, during the formal firing process, a first heat preservation zone and a second heat preservation zone are set respectively. The first heat preservation zone is 850-950℃ and is maintained for 1-2 hours, and the second temperature zone is 1050-1150℃ and is maintained for 1.5-2.5 hours.

[0012] Preferably, in step S3, the fired ceramic sanitary ware product's main glaze surface is treated with a 5-10% hydrofluoric acid solution at a temperature of 80-100℃ for 30-60 seconds to micro-etch the ceramic sanitary ware product's main glaze surface, forming a nanoscale microporous structure on the glaze surface. A silver ion-containing impregnation solution is sprayed onto the activated ceramic sanitary ware product's main glaze surface and subjected to a penetration treatment under negative pressure for 10-30 minutes, allowing silver ions to penetrate into the surface glass network of the glaze surface through the micropores.

[0013] The present invention also proposes a ceramic sanitary ware product using the aforementioned antibacterial ceramic preparation method, wherein the antibacterial rate of the main surface of the ceramic sanitary ware product against Escherichia coli and Staphylococcus aureus is ≥99%, and the antibacterial rate remains ≥98% after durability testing.

[0014] The technical solution of this invention has the following advantages over the prior art: This invention achieves long-lasting antibacterial properties in ceramic sanitary ware products through synergistic innovation in the glaze system and firing process. Regarding antibacterial performance, the use of silver-loaded zirconium phosphate antibacterial agent, combined with a step-fired process of pre-coating and microcrystalline anchoring, increases the silver ion retention rate to over 92%, resulting in effective and long-lasting antibacterial action. The use of lithium low-expansion powder effectively alleviates thermal mismatch stress and prevents glaze cracking. Calcite, talc, and calcined kaolin in situ generate anorthite and cordierite microcrystals, forming a microcrystalline-glass composite structure that enhances the hardness, wear resistance, and chemical corrosion resistance of the glaze surface. High-transparency frit powder and a precise silicon-aluminum ratio ensure a glossy, clear, and warm glaze surface. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a flowchart of the method for preparing antibacterial ceramics according to the present invention.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention proposes a long-lasting antibacterial glaze.

[0020] The long-lasting antibacterial glaze in this embodiment of the invention comprises, by mass percentage, 9-14% potassium feldspar, 28-35% quartz, 11-16% lithium low-expansion powder, 15-22% high-permeability frit powder, 8-14% calcite, 6-11% calcined kaolin, 4-8% talc, 0.5-2.5% zinc oxide, and 4-11% antibacterial powder.

[0021] The potassium feldspar of this invention contains ≥10% potassium oxide and ≤0.15% ferric oxide, with a mesh size of 200-325. As the main solvent component of the glaze in this invention, potassium feldspar decomposes into potassium oxide at high temperatures, lowering the melting temperature of the glaze and promoting glass phase formation. Simultaneously, potassium ions, as network ions, can break silicon-oxygen bridge bonds, increasing the number of non-bridged oxygen atoms and providing bonding sites for silver ions.

[0022] In the quartz of this invention, the silicon dioxide content is ≥98.5%, the ferric oxide content is ≤0.05%, and the mesh size is 325. Quartz is the framework forming agent of the glaze glass mesh structure, and its content directly affects the chemical stability, hardness, and coefficient of thermal expansion of the glaze. The quartz content of this invention ranges from 28-35%, giving the glaze sufficient durability and mechanical strength.

[0023] The lithium low-expansion powder of this invention is made from spodumene concentrate, with a lithium oxide content ≥4.5%, an alumina content ≥25%, and a coefficient of thermal expansion ≤1.2×10⁻⁶. -6 The spodumene has a particle size D50 of 15-25 μm and is composed of α-spodumene or β-spodumene, preferably β-spodumene calcined at 1050-1100℃, which improves its low expansion characteristics and reduces the viscosity of the high-temperature melt. In the firing process of ceramic sanitary ware products, the low expansion characteristics of spodumene effectively alleviate the internal stress caused by the difference in thermal expansion coefficients between the glaze and the body, preventing glaze cracking. Simultaneously, the small ionic radius and high field strength of lithium ions can reduce melt viscosity and promote sintering densification, providing favorable kinetic conditions for the uniform dispersion of silver ions used for antibacterial purposes.

[0024] The high-transmittance frit powder of this invention first needs to be melted at 1300-1400℃, water-quenched, and crushed to 325 mesh. The chemical composition of the high-transmittance frit powder of this invention, calculated by mass percentage, includes 58-62% silicon dioxide, 14-16% aluminum oxide, 6-8% calcium oxide, 2-4% magnesium oxide, 2-3% potassium oxide, 3-4% sodium oxide, and 3-4% zinc oxide. The high-transmittance frit powder used in this invention has a visible light transmittance ≥85%, and can rapidly form a continuous glass phase at lower temperatures, encapsulating the silver-loaded antibacterial agent and preventing the silver ions from being reduced and deactivated at high temperatures.

[0025] In the calcite of this invention, the calcium oxide content is ≥55%, the magnesium oxide content is ≤0.5%, and all particles pass through a 325-mesh sieve. This invention utilizes the decomposition of calcite at high temperatures to generate calcium oxide. Calcium ions, acting as network ions, can further break silicon-oxygen bridges and increase the number of non-bridged oxygen atoms. Furthermore, they can react with alumina and silica to generate anorthite grains, thereby improving the hardness and wear resistance of the glaze.

[0026] The calcined kaolin of this invention contains an alumina content of ≥42%. It is calcined at 800-900℃ to completely remove moisture from its internal structure, forming a highly reactive metakaolinite phase with a fineness of 325 mesh. During the calcination process of ceramic sanitary ware products, calcined kaolin is the main source of alumina. Under high-temperature conditions, it reacts with silica to form mullite nuclei, or with calcium oxide and magnesium oxide to form anorthite and cordierite, which are key components for the microcrystalline reinforcement structure.

[0027] In the talc of the present invention, the magnesium oxide content is ≥30%, the calcium oxide content is ≤1%, and the fineness is 325 mesh. The talc decomposes at high temperature to generate magnesium oxide. The magnesium ions react with aluminum oxide and silicon dioxide to form cordierite crystals. These crystals have a low coefficient of thermal expansion and high hardness, which is beneficial to improving the thermal shock resistance and wear resistance of the glaze.

[0028] The technical solution of this invention adds zinc oxide with a particle size D50 of 1-3μm. Active zinc oxide is used to enhance its fluxing and strengthening effects. In the glaze, zinc oxide can lower the melting temperature and promote the formation of the glass phase. At the same time, zinc ions can participate in the glass network structure, improving the chemical stability and gloss of the glaze.

[0029] The antibacterial powder used in this invention has the chemical formula (ZrO2)_x(P2O5)_y(Ag2O)_z, and is a silver-loaded zirconium phosphate antibacterial agent. The silver oxide loading is 1.0-5.0 wt%, preferably 3.0 wt%. The particle size D50 of the antibacterial powder is 1-10 μm, preferably 4-6 μm, and the specific surface area is 5-15 m² / g. It is prepared via ion exchange, where silver ions are located in the interlayer domains of the zirconium phosphate layered structure, forming stable Zr-O-Ag chemical bonds, thus giving it thermal stability.

[0030] When the long-acting antibacterial powder of the present invention is applied to the surface of ceramic sanitary ware products, under normal use, the silver ions in the interlayer domain are slowly released through the ion exchange mechanism. They are electrostatically adsorbed with the negatively charged groups on the cell walls and cell membranes of bacteria attached to the surface of the ceramic sanitary ware products, penetrate the cell membrane and enter the cell interior, and bind to enzyme proteins containing sulfhydryl groups, thereby inactivating them and inhibiting the growth and reproduction of bacteria.

[0031] Please see Figure 1 The present invention also proposes a method for preparing antibacterial ceramics using long-lasting antibacterial glaze, comprising the following steps: Step S1: Prepare ceramic blank materials, perform high-pressure slip casting to form ceramic blanks, and dry them after demolding to obtain ceramic sanitary ware product blanks; Step S2: Apply antibacterial glaze to the surface of the ceramic sanitary ware product body to form an antibacterial glaze coating; Step S3: After drying the ceramic sanitary ware product blank coated with antibacterial glaze, send it into the kiln for firing and molding to obtain the main body of the ceramic sanitary ware product with long-lasting antibacterial function.

[0032] Preferably, in step S2 above, the antibacterial glaze is applied by spraying or dipping, and the antibacterial glaze is applied to the inner and / or outer wall surfaces of the ceramic sanitary ware product body, with an application amount of 350-550 g / m², and the glaze layer thickness after glazing is 0.3-0.6 mm.

[0033] Preferably, in step S3, the firing temperature range for the ceramic sanitary ware product blank is 1200-1250℃, and the firing cycle is 12-20 hours.

[0034] Specifically, the technical solution of this invention involves preparing the blank by weighing 30-40% spherical clay, 15-20% quartz, 20-25% feldspar, 10-15% calcined kaolin, and 5-10% waste porcelain powder. Water glass (0.5-1.0% by dry weight) and soda ash (0.1-0.3% by dry weight) are added as electrolytes. Water is added to adjust the slurry moisture content to 30-33%. The slurry is then ball-milled to a fineness of 250 to obtain the slurry for casting. High-pressure casting is then performed, injecting the prepared slurry into a ceramic sanitary ware product mold under a pressure of 0.8-1.2 MPa and holding the pressure for 15-30 minutes. After the blank reaches the predetermined thickness, excess slurry is discharged, and pressure is maintained for another 5-10 minutes to ensure uniform moisture content. After demolding, the main wet blank of the ceramic sanitary ware product is obtained. After demolding, the wet body of the ceramic sanitary ware product is placed in a drying kiln and dried at 50-80℃ for 12-24 hours. Then, the temperature is increased to 100-120℃ and drying continues until the residual moisture content of the body is ≤1.0%. For ceramic sanitary ware products with complex structures, such as siphon bends, auxiliary ventilation drying is required to ensure even moisture removal and prevent drying cracking. After drying, the body is trimmed and polished to remove parting lines and burrs. The surface is then wiped with a damp sponge to remove dust, preparing it for glazing.

[0035] Preferably, the firing temperature range for the ceramic sanitary ware product blank according to the technical solution of the present invention is 1200-1250℃, and the firing cycle is 12-20 hours. In the actual product manufacturing process of the present invention, after the product enters the kiln, it is maintained at a low temperature of 600℃ from room temperature for 140 minutes to facilitate drainage. Then, it is maintained at a medium temperature of 1100℃ for 200 minutes to remove impurities and perform preliminary firing. Finally, it is maintained at a high temperature of 1230℃ for 160 minutes to achieve preliminary firing and shaping of the glaze on the surface of the blank. A holding temperature of 1230℃ to 1150℃ is maintained for 60 minutes to ensure the smoothness of the glaze surface, and a cooling temperature of 1150℃ to 45℃ is maintained for 640 minutes.

[0036] By setting a first temperature range during the medium temperature period and a second temperature range during the high temperature period, and maintaining the temperature for a certain period of time within these two temperature ranges.

[0037] Specifically, the first heat preservation zone is 850-950℃ for 1-2 hours. Within this temperature range, silver ions in the silver-loaded zirconium phosphate begin to activate but have not yet reached a significant reduction temperature. By employing this heat preservation treatment, silver ions can undergo lattice rearrangement within the layered structure of zirconium phosphate, forming a more stable Zr-Ag-OP bond configuration. Simultaneously, this first heat preservation zone is also the temperature range where the glass phase in the glaze begins to form in large quantities. This heat preservation treatment allows the glass phase to form a preliminary pre-coating layer on the antibacterial agent particles, preventing the migration and reduction of silver ions during subsequent heating.

[0038] Within the first heat preservation zone, the potassium feldspar and frit components of the glaze begin to melt extensively, forming a low-viscosity glassy phase. After 1-2 hours of heat preservation, the glassy phase has sufficient time to form a dense coating layer on the surface of the silver-loaded antibacterial agent particles. This coating layer isolates the antibacterial agent particles from the external atmosphere, preventing direct contact between oxygen or reducing gases and silver ions at high temperatures. Furthermore, the non-bridging oxygen in the coating layer reacts with the silver ions on the surface of the antibacterial agent particles to form Si-O-Ag. + Covalent bonds fix silver ions on the surface of antibacterial agent particles, inhibiting their outward diffusion.

[0039] The second temperature range is 1050-1150℃, and the temperature is maintained for 1.5-2.5 hours. This temperature range corresponds to the temperature range of the anorthite (CaAl2Si2O8) and cordierite (Mg2Al4Si5O8) in the glaze layer. 18 The temperature at which microcrystals precipitate in large quantities. Heat preservation treatment promotes the uniform precipitation of microcrystals around the antibacterial agent particles, firmly anchoring the antibacterial agent particles within the glaze structure and further inhibiting silver ion diffusion and reduction. Simultaneously, the dense microcrystalline-glass composite structure significantly improves the wear resistance and chemical corrosion resistance of the glaze surface.

[0040] Within this temperature range, the calcium oxide generated from the decomposition of calcite reacts with magnesium oxide and silicon oxide to form anorthite crystals, while the magnesium oxide generated from the decomposition of talc reacts with aluminum oxide and silicon oxide to form cordierite crystals. After a heat treatment of 1.5-2.5 hours, the uniform precipitation of microcrystals around the antibacterial agent particles is promoted, forming a three-dimensional interlocking structure of microcrystals-antibacterial agent-glass phase. This structure not only firmly anchors the antibacterial agent particles in the glaze layer, preventing migration and segregation during subsequent cooling, but also the dense microcrystal-glass composite structure effectively inhibits the outward diffusion of silver ions, achieving long-lasting and sustained-release antibacterial effects.

[0041] Existing ceramic sanitary ware products typically employ a continuous heating-holding-cooling curve during firing, without specifying a dedicated holding period for antibacterial agent stabilization. However, this invention improves the retention rate of silver ions during an ultra-long firing cycle and utilizes a stepped firing temperature, increasing the silver ion retention rate from approximately 65% ​​in conventional firing to over 92%.

[0042] The present invention discloses a method for preparing long-lasting antibacterial glaze and antibacterial ceramics. By introducing lithium low-expansion powder into the glaze formulation, it achieves an extremely low coefficient of thermal expansion, alleviating the thermal mismatch stress between the glaze layer and the body during the 12-20 hour firing and slow cooling process of ceramic sanitary ware products, thus improving the thermal shock resistance and structural integrity of the glaze layer. Simultaneously, lithium ions, as a network modifier, continuously reduce melt viscosity during high-temperature, long-term firing, promoting the formation of non-bridging oxygen in the glass phase and providing more bonding sites for silver ions. Combined with the stable chemical bonds formed by silver ions in the interlayer domains of the layered structure in the silver-loaded zirconium phosphate antibacterial agent, and the rapid formation of a continuous, dense glass phase coating by high-transparency frit powder and calcite in the early stages of firing, the stability of silver ions within the ultra-long firing cycle of the ceramic sanitary ware product body is achieved, preventing their reduction to elemental silver at high temperatures and ensuring the glaze layer possesses long-lasting antibacterial activity.

[0043] Preferably, the antibacterial glaze layer of the present invention can also be designed as a double-layer composite structure of a bottom antibacterial-rich layer and a top transparent protective layer. The bottom antibacterial-rich layer uses an antibacterial powder content increased to 8-15%, applied to the surface of the ceramic sanitary ware body, with a glaze application rate of 250-300 g / m² and a glaze thickness of approximately 0.25-0.35 mm. This layer bears the main antibacterial function, and the high antibacterial agent content ensures sufficient silver ions in the glaze layer. The top transparent protective layer uses a high-transparency base glaze without added antibacterial powder, that is, the antibacterial powder is removed from the formula, applied on top of the bottom antibacterial-rich layer, with a glaze application rate of 150-200 g / m² and a glaze thickness of approximately 0.15-0.25 mm. During the firing process, the top transparent protective layer melts before the bottom antibacterial-rich layer to form a dense glass layer, sealing the bottom antibacterial-rich layer and preventing the silver ions in the bottom antibacterial-rich layer from diffusing outwards or being reduced at high temperatures. The transparent protective layer has moderate ion penetration channels, ensuring that silver ions can be slowly released into the glaze for long-lasting antibacterial effect. The highly transparent formula of the protective layer gives the glaze excellent gloss and transparency.

[0044] In traditional techniques, antibacterial glazes are typically single, homogeneous layers. The double-layer structure of this invention utilizes a transparent protective layer on the surface to protect the underlying antibacterial-rich layer, overcoming defects such as glaze opacity and pinholes caused by high antibacterial agent dosages. This double-layer structure allows for an increase in antibacterial powder dosage to 15% without reducing glaze gloss, resulting in approximately a 30% improvement in antibacterial durability.

[0045] In actual construction, the first step involves spraying a base layer of antibacterial glaze onto the surface of the ceramic sanitary ware product using a spray glazing process. The glaze application rate is 280g / m², and the glaze layer thickness is approximately 0.3mm. After natural drying for 1 hour, a top layer of transparent protective glaze is sprayed onto the surface of the base layer of antibacterial glaze using the same spray glazing process. The glaze application rate is 180g / m², and the glaze layer thickness is approximately 0.2mm. This is then allowed to dry naturally for 2 hours. During the low-temperature preheating stage of firing, the room temperature is increased to 300℃ at a rate of 25℃ / h and held for 1.5 hours. The medium-temperature decomposition stage involves increasing the temperature to 950℃ at a rate of 35℃ / h and holding for 1.5 hours, which corresponds to the first holding period. The high-temperature firing stage involves increasing the temperature to 1150℃ at a rate of 25℃ / h and holding for 2 hours, which corresponds to the second holding period. Finally, the temperature is increased to the maximum temperature of 1220℃ at a rate of 20℃ / h and held for 2 hours. The cooling stage involves cooling to 900°C at 40°C / h, and then cooling to room temperature at 60°C / h, with a total firing cycle of approximately 16 hours.

[0046] To further enhance the antibacterial performance of the long-lasting antibacterial glaze of this invention, the technical solution involves introducing antibacterial components onto the glaze surface of the fired ceramic sanitary ware product through liquid-phase infiltration or spray-heat treatment. The glaze surface activation treatment involves treating the glaze surface of the fired ceramic sanitary ware product with a 5-10% hydrofluoric acid solution at 80-100℃ for 30-60 seconds, micro-etching the glaze surface to form a nanoscale microporous structure. The pore size of the nanoscale microporous structure is 50-200 nm, and the pore depth is 100-500 nm, increasing the specific surface area and active sites of the glaze surface.

[0047] Then, an impregnation solution containing silver ions, wherein the silver source is silver nitrate or silver acetate at a concentration of 0.5-2.0 wt%, and containing an appropriate amount of surfactant as a penetration aid, is sprayed onto the activated glaze surface. The surface is then subjected to a negative pressure of -0.05 to -0.08 MPa for 10-30 minutes, allowing silver ions to penetrate into the glass network on the glaze surface through micropores. This invention utilizes a nanoscale microporous structure formed by micro-etching of the glaze surface. This structure not only provides anchoring points for silver ions but also possesses a physical antibacterial effect; its sharp edges can pierce bacterial cell walls, creating a dual antibacterial effect combined with the chemical antibacterial effect of silver ions.

[0048] Preferably, the antibacterial powder is pre-composite treated before being added to the glaze to further improve its high-temperature stability. The silver-loaded zirconium phosphate antibacterial powder is dispersed in a Li-containing... + Ca 2+ Zn 2+ In a mixed salt solution, Li + :Ca 2+ :Zn 2+ The molar ratio of the two components was 2:1:0.5, and the mixture was stirred at 80°C for 2 hours. Through ion exchange reaction, a (Li, Ca, Zn)-phosphate protective layer with a thickness of 10-50 nm was formed on the surface of the silver-loaded zirconium phosphate particles. The pretreated antibacterial powder was dispersed in an ethanol solution of silane coupling agent KH-570 at a concentration of 2-5%, and stirred at 60°C for 1 hour to impart hydrophobic properties to the surface of the antibacterial powder. The presence of the protective layer gives the antibacterial powder higher chemical stability in the glaze. During high-temperature firing, the protective layer preferentially reacts with the glaze melt, delaying the erosion of the antibacterial powder by the glaze melt. Surface hydrophobic modification improves the dispersibility of the antibacterial powder in the glaze slurry, avoiding uneven antibacterial performance and glaze defects caused by agglomeration.

[0049] Furthermore, the glaze surface is sealed to improve its density and antibacterial durability. By mass percentage, the sealing solution comprises 20% solids, 40-60% nano-silica sol with a particle size of 10-20 nm, 10-20% tetraethyl orthosilicate, 20-30% ethanol, 5-10% deionized water, and 0.5-1% glacial acetic acid. The mixture is stirred and mixed at room temperature for 2 hours to obtain a uniform and transparent sealing solution. The sealing solution is sprayed onto the glaze surface of the fired ceramic sanitary ware product at an atomization pressure of 0.2-0.3 MPa, with a spraying amount of 50-80 g / m². The sprayed ceramic sanitary ware product is then heat-treated at 150-200℃ for 30-60 minutes, causing the nano-silica sol and tetraethyl orthosilicate in the sealing solution to hydrolyze and condense, forming a transparent silica sealing film with a thickness of 50-100 nm on the glaze surface. This sealing film further improves the density of the glaze surface and blocks the penetration channels of dirt and corrosive media. Furthermore, the sealing membrane itself is rich in silanol groups, exhibiting hydrophilicity and self-cleaning effects, while also regulating the release rate of silver ions to extend the antibacterial efficacy. The nanoscale membrane thickness does not alter the appearance and texture of the glaze, and has no negative impact on gloss and transparency.

[0050] This invention utilizes the synergistic effect of calcite, talc, and calcined kaolin. During high-temperature, long-term firing, the calcium oxide generated from the decomposition of calcite, the magnesium oxide generated from the decomposition of talc, and the active alumina and silicon dioxide provided by calcined kaolin all participate in the reaction, generating microcrystals such as anorthite and cordierite. These crystals precipitate uniformly and are embedded in a highly transparent glass phase, forming a microcrystalline-glass composite structure. On one hand, this structure significantly improves the hardness and wear resistance of the main glaze surface of ceramic sanitary ware products, sufficient to resist the mechanical wear of daily cleaning and scrubbing. On the other hand, anorthite belongs to the triclinic crystal system, and its refractive index is similar to that of the glaze glass phase, avoiding strong light scattering and ensuring high transparency and high gloss of the glaze layer, giving ceramic sanitary ware products a good appearance and texture. In addition, the dense microcrystalline-glass composite structure effectively blocks the penetration channels of water molecules, dirt, and detergents, resulting in better stain resistance and chemical corrosion resistance of the ceramic sanitary ware glaze surface, and long-term stability of the ceramic sanitary ware products in humid and polluted environments.

[0051] Preferably, the technical solution of this invention, through precise control of the SiO2 / Al2O3 molar ratio in the overall chemical composition of the glaze (8-15:1) and the introduction of lithium low-expansion powder and high-penetration frit powder, ensures the rheological properties and sintering densification behavior of the glaze layer at high temperatures. This facilitates the rapid formation of a high-viscosity continuous glass phase in the early stages of firing, fixing the silver ions released by the silver-loaded antibacterial agent, inhibiting their diffusion and aggregation, and ensuring the uniform distribution of antibacterial components in the relatively thin 0.3-0.6 mm glaze layer of ceramic sanitary ware products. During daily use, silver ions on the glaze surface are continuously released at an extremely low rate, achieving long-lasting slow-release antibacterial effects. At the same time, the dense glaze structure avoids excessive dissolution of antibacterial components, ensuring their effectiveness throughout the entire service life.

[0052] The formula of this invention is rationally proportioned, enabling the glaze to achieve excellent antibacterial properties while maintaining the high gloss, high transparency, and delicate texture necessary for the main body of the ceramic sanitary ware product. In particular, the use of low-expansion lithium powder and high-transparency frit powder gives the glaze a warm and translucent texture, meeting the aesthetic requirements of ceramic sanitary ware products as high-quality sanitary ware.

[0053] This invention also proposes a ceramic sanitary ware product made using a long-lasting antibacterial glaze and an antibacterial ceramic preparation method. The main surface of the ceramic sanitary ware product is covered with the long-lasting antibacterial glaze of this invention, and the antibacterial rate of the main surface of the ceramic sanitary ware product against Escherichia coli and Staphylococcus aureus is ≥99%, and the antibacterial rate is still ≥98% after durability testing. Example 1

[0054] The long-lasting antibacterial glaze formula of Example 1 of the present invention comprises, by mass percentage, 12% potassium feldspar, 32% quartz, 14% β-spodumene, 18% high-transparency frit powder, 10% calcite, 7% calcined kaolin, 5% talc, 1% zinc oxide, and 6% silver-loaded zirconium phosphate antibacterial powder with a silver loading of 3.0 wt% and a D50 of 5 μm.

[0055] After accurately weighing each raw material according to the above formula, potassium feldspar, quartz, β-spodumene, calcite, calcined kaolin, talc, zinc oxide, and high-transparency frit powder are added sequentially to a ball mill. Sodium carboxymethyl cellulose (0.4% of the total dry mass) is added as a suspending agent, sodium tripolyphosphate (0.5% of the total dry mass) as a desiccant, and clean water (40% of the total dry mass) is added. Alumina balls are used as the grinding media, with a ball-to-material mass ratio of 1.8:1. The ball mill speed is controlled at 25-30 r / min, and the milling time is 10-12 hours. After milling, silver-loaded zirconium phosphate antibacterial powder is added and mixed and dispersed at low speed for 30 minutes to ensure that the antibacterial powder is uniformly dispersed in the glaze slurry system without being over-ground and damaging its particle morphology. Finally, the specific gravity of the glaze slurry is adjusted to 1.70-1.75, and the residue on a 325-mesh standard sieve is controlled to be ≤0.3%, yielding the antibacterial glaze slurry.

[0056] The prepared antibacterial glaze slurry is uniformly sprayed onto the surface of the dried ceramic sanitary ware product blank using a high-pressure spraying process with an atomization pressure of 0.5-0.7 MPa. The glaze application rate is controlled at 400-450 g / m², and the glaze layer thickness is approximately 0.4-0.5 mm. After glazing, the ceramic sanitary ware product blank is allowed to air dry at room temperature for 2-4 hours to allow the moisture in the glaze layer to fully evaporate, preventing bubble defects during subsequent firing.

[0057] After glazing and drying, the ceramic sanitary ware blanks are loaded into kiln cars and pushed into a shuttle kiln or tunnel kiln for high-temperature firing. The firing process includes a low-temperature preheating stage, where the temperature is increased from room temperature to 300℃ at a rate of 20-30℃ / h and held for 1-2 hours to slowly expel residual structural water and organic matter from the blank. In the medium-temperature decomposition stage, the temperature is increased to 950-1000℃ at a rate of 30-40℃ / h and held for 1-2 hours to fully decompose the calcite in the glaze and allow the quartz to undergo a crystal transformation—from β-quartz to α-quartz, and then to α-tridymite—while the glaze begins to melt. In the high-temperature firing stage, the temperature is increased to the maximum firing temperature of 1200-1230℃ at a rate of 20-25℃ / h and held at this maximum temperature for 2-3 hours to allow the glaze to fully melt, spread, and bond well with the blank, while also promoting the uniform precipitation of the microcrystalline structure of anorthite and cordierite. During the cooling stage, the temperature is first slowly cooled to 900℃ at a rate of 30-50℃ / h, and then cooled to room temperature at a rate of 50-80℃ / h. The entire firing cycle is controlled within 14-18 hours. Example 2

[0058] The long-lasting antibacterial glaze formula of Example 2 of the present invention comprises, by mass percentage, 9% potassium feldspar, 35% quartz, 11% lithium feldspar, 15% high-transparency frit powder, 14% calcite, 6% calcined kaolin, 4% talc, 2.5% zinc oxide, and 8% silver-loaded silicate antibacterial powder with a silver loading of 4.0 wt%.

[0059] Among them, petalite and spodumene both belong to lithium aluminum silicate minerals, and their coefficient of thermal expansion is 1.4 × 10⁻ 6 At / ℃, it can still exert low expansion and fluxing effects at high temperatures, and can introduce an appropriate amount of lithium oxide into the glaze layer. The silver-loaded silicate antibacterial agent is selected from silver-loaded zeolite or silver-loaded montmorillonite, whose layered or porous structure is conducive to the slow release of silver ions, with D50 controlled at 6-8μm and specific surface area of ​​20-40m² / g.

[0060] The technical differences between this embodiment and Example 1 are as follows: In the preparation of the antibacterial glaze slurry in this embodiment, to accommodate the higher quartz content and lower calcined kaolin content in the formula, the ball milling time is extended to 12-14 hours to ensure sufficient refinement of the quartz particles and prevent white spot defects caused by incomplete melting during firing. The glazing process combines dipping and spraying. The inner wall of the ceramic sanitary ware product is glazed using the pouring method, where the glaze slurry is injected into the body, left for 5-10 seconds, and then poured out. The outer wall is glazed using spraying. The total glaze application amount is 400-450 g / m². In the firing regime, the maximum firing temperature is adjusted to 1210-1240℃, and the firing cycle is extended to 16-20 hours to compensate for the possible decrease in melting rate due to the lower lithium content. The remaining process steps and parameters are consistent with those of Example 1. Example 3

[0061] The long-lasting antibacterial glaze formula of Example 3 of the present invention comprises, by mass percentage, 14% potassium feldspar, 28% quartz, 16% β-spodumene, 22% high-transparency frit powder, 8% calcite, 8% calcined kaolin, 8% talc, 0.5% zinc oxide, and 4.5% silver-loaded glass antibacterial powder with a silver loading of 2.0 wt%.

[0062] The silver-loaded glass antibacterial agent is made by uniformly doping silver ions into a glass network structure using borosilicate glass as a matrix through a melting method, followed by crushing and grinding. Its chemical composition, by mass percentage, includes: SiO2 45-55%, B2O3 15-25%, Na2O 5-10%, Ag2O 2-5%. The antibacterial agent has a D50 of 3-5 μm. Its glassy structure itself has good compatibility with the glaze melt, which is beneficial for the slow release and uniform distribution of silver ions.

[0063] The process differs from Example 1 in the following technical features: Because the total amount of low-expansion lithium powder and high-transparency frit powder in this example's formulation is higher, resulting in a lower melting temperature and better fluidity, the firing regime is adjusted. The maximum firing temperature is increased to 1220-1250℃, but the high-temperature holding time is shortened to 1.5-2 hours to avoid excessive glaze flow leading to glaze defects. Simultaneously, rapid heating helps suppress the premature release of silver ions from the antibacterial agent in the silver-loaded glass. The glaze application amount is adjusted to 450-500 g / m² to obtain a thicker glaze layer, fully utilizing its high transparency.

[0064] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that lithium low-expansion powder is not added; the missing mass fraction is made up by equal amounts of quartz and potassium feldspar in a 2:1 ratio, while the remaining components and their mass percentages remain unchanged. The specific formula is: 14.7% potassium feldspar, 38.7% quartz, 18% high-transparency frit powder, 10% calcite, 7% calcined kaolin, 5% talc, 1% zinc oxide, and 6% silver-loaded zirconium phosphate antibacterial powder. The preparation process is exactly the same as in Example 1. This comparative example aims to consider the impact of the absence of lithium low-expansion powder on the thermal shock resistance and antibacterial durability of the glaze. Since the coefficient of thermal expansion of the main body of ceramic sanitary ware products is typically 7.0-8.0 × 10⁻⁶... -6 / ℃, while the coefficient of thermal expansion of conventional glazes is approximately 6.5-7.5×10. -6 / ℃, and there is a certain difference between the two. During the firing and slow cooling process that lasts 14-18 hours, without the stress buffering effect of low expansion components, large residual stress can easily accumulate in the glaze layer, leading to the formation of microcracks.

[0065] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that calcined kaolin and talc are not added; the missing mass fractions are made up by equal amounts of quartz and potassium feldspar in a 1:1 ratio, while the other components remain unchanged. The specific formula is: 18% potassium feldspar, 38% quartz, 14% β-spodumene, 18% high-transparency frit powder, 10% calcite, 1% zinc oxide, and 6% silver-loaded zirconium phosphate antibacterial powder. The preparation process is exactly the same as in Example 1.

[0066] This comparative example aims to consider the impact of the absence of calcined kaolin and talc on the abrasion resistance, density, and transparency of the glaze. Calcined kaolin and talc are key raw materials for the formation of anorthite and cordierite microcrystals. The absence of these two raw materials will lead to a significant reduction in the crystalline phase content in the glaze layer, affecting the hardness and abrasion resistance of the glaze. At the same time, it may also lead to a decrease in the density of the glaze due to the inability to form a microcrystalline-glass composite structure.

[0067] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the antibacterial powder was replaced with an equal mass of commercially available ordinary silver nanoparticles with an average particle size of 50 nm, and the carrier-type antibacterial agent such as silver-loaded zirconium phosphate as defined in this invention was not used. The remaining components were exactly the same as in Example 1. The preparation process was the same as in Example 1.

[0068] This comparative example aims to consider the difference in thermal stability between carrier-based antibacterial agents and ordinary nano-silver powder under high-temperature and long-term firing conditions in ceramic sanitary ware products. Ordinary nano-silver powder has higher surface energy and mobility at high temperatures, and is prone to melting, agglomeration, or redox reactions, thus becoming inactive.

[0069] Comparative Example 4 Comparative Example 4 uses a commercially available antibacterial glaze for ordinary ceramic sanitary ware products. Its main components are: 45% potassium feldspar, 25% quartz, 15% calcite, 10% calcined talc, 2% zinc oxide, and 3% commercially available silver-based antibacterial agent (Ag₂O powder without carrier protection). The antibacterial ceramic sanitary ware product was prepared using the same glazing and firing process as in Example 1. This comparative example aims to compare the performance advantages of the present invention's technical solution compared to existing commercially available products.

[0070] Comparative Example 5 The difference between Comparative Example 5 and Example 1 lies in the firing regime: specifically, the maximum firing temperature is increased from 1200-1230℃ to 1280℃, while other conditions remain unchanged. This comparative example aims to consider the impact of excessively high temperatures on the glaze system and antibacterial properties of the present invention. In actual production of ceramic sanitary ware products, if the kiln temperature control is inaccurate or the kiln loading position is improper, the local temperature may be too high. Therefore, considering high-temperature tolerance is of practical significance for process stability control.

[0071] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that the amount of antibacterial powder added exceeds the range defined by this invention. Specifically, the amount of antibacterial powder added is 15%, and the amount of quartz and potassium feldspar is reduced accordingly to maintain the total amount at 100%. The specific formula is: 10% potassium feldspar, 27% quartz, 14% β-spodumene, 18% high-transparency frit powder, 10% calcite, 7% calcined kaolin, 5% talc, 1% zinc oxide, and 15% silver-loaded zirconium phosphate antibacterial powder. The preparation process is the same as that of Example 1.

[0072] This comparative example aims to consider the impact of excessive antibacterial powder addition on the transparency and physicochemical properties of the glaze. Excessive addition of antibacterial powder may cause antibacterial agent particles to agglomerate within the glaze layer, forming light scattering centers, reducing glaze transparency, and potentially compromising the structural density of the glaze layer.

[0073] To accurately evaluate the overall performance of the antibacterial ceramic sanitary ware products obtained in each embodiment and comparative example, the present invention adopts the following unified test methods and standards.

[0074] For antibacterial performance testing, the film application method was used in accordance with the People's Republic of China Building Materials Industry Standard JC / T 897-2014 "Antibacterial Properties of Antibacterial Ceramic Products". The test bacteria were *Escherichia coli*, a representative Gram-negative bacterium, and *Staphylococcus aureus*, a representative Gram-positive bacterium. Samples of 50mm × 50mm were cut from the glazed surface of the ceramic sanitary ware product, prioritizing areas with frequent contact with the human body, such as the seat ring and water seal bend. Nutrient broth was used as the culture medium, and viable bacteria were counted using plate counting agar.

[0075] The specific operating steps are as follows: Place the sample to be tested in a sterile petri dish, add PBS (pH=7.2) containing the suspension of the bacteria to be tested, ensuring the bacterial suspension evenly covers the glaze surface, cover with a sterile film, and incubate for 24 hours at 37±1℃ and relative humidity >90%. After incubation, wash away any remaining viable bacteria on the sample surface with elution buffer, inoculate onto a culture medium, and incubate at 37℃ for 24 hours to count the viable bacteria. Calculate the antibacterial rate R using the following formula: R (%) = (A - B) / A × 100%; Where A is the blank control sample, which is the average viable count of ordinary glazed tiles without antibacterial glaze, and B is the average viable count of the antibacterial sample to be tested.

[0076] For the antimicrobial durability test, the boiling water immersion method was adopted according to the antimicrobial durability test method in JC / T 897-2014 standard. The sample to be tested was completely immersed in deionized water and heated in a boiling water bath for 24 hours. After removal, it was dried in an oven at 100±2℃ for 2 hours and cooled to room temperature. The antimicrobial rate of the sample after durability treatment was determined according to the above antimicrobial performance test method to evaluate its long-term effectiveness of antimicrobial performance.

[0077] In addition, to better reflect the actual usage environment of ceramic sanitary ware products, a simulated usage test was added. The samples were soaked in an acidic solution with pH=5.0 to simulate an acidic cleaning agent environment and an alkaline solution with pH=11.0 to simulate an alkaline cleaning agent environment for 72 hours, and then their antibacterial rate was tested again.

[0078] For abrasion resistance testing, refer to GB / T 3810.7-2016 Ceramic Tile Test Methods Part 7: Determination of Abrasion Resistance of Glazed Tile Surfaces. Use an abrasion testing machine with a specified abrasive (alumina, F80) and a load (750±5g) to grind the glaze surface. After each certain number of revolutions, rub the glaze surface with a steel ball to observe for visible wear until obvious wear marks appear. Record the number of revolutions at this point and assess the abrasion resistance level based on the number of revolutions. The specific classifications are: Level 1 (≤150 revolutions), Level 2 (150-300 revolutions), Level 3 (300-600 revolutions), Level 4 (600-750 revolutions), Level 5 (750-1500 revolutions), and a special grade higher than Level 5 (such as 2100 revolutions, 6000 revolutions, etc.). For ceramic sanitary ware products, abrasion resistance directly affects their service life under daily cleaning and scrubbing conditions.

[0079] Regarding the gloss test of the glaze, the specular gloss of the glaze was measured using a gloss meter at an incident angle of 60°, referring to GB / T 13891-2008 "Method for Determination of Specular Gloss of Building Facing Materials". The gloss of the glaze of ceramic sanitary ware products is generally required to be above 85°. This test was used to evaluate the impact of antibacterial glaze on the appearance and texture of the product.

[0080] Regarding transparency evaluation, a combination of visual observation and instrumental measurement was used. Under the same lighting conditions, the sample was placed on an observation table with a black background, and five professional technicians subjectively rated the transparency of the glaze, classifying it into three levels: "high transparency," "medium transparency," and "low transparency / opacity." Simultaneously, a UV-Vis spectrophotometer was used to measure the visible light transmittance of the glaze at a wavelength of 550 nm. The thickness was uniformly set at 0.5 mm to quantitatively characterize its transparency, with a transmittance ≥80% defined as high transparency.

[0081] For the stain resistance test, the procedure was conducted according to GB / T 3810.14-2016 Ceramic Tiles Test Methods Part 14: Determination of Stain Resistance. Green dye (stain source A) and iodine tincture (stain source C) from light oil were selected as contaminants. Additionally, considering the characteristics of ceramic sanitary ware products, ink (blue-black ink) and coffee liquid were added as simulated contaminants. The contaminants were dropped onto the glaze and covered, then left at room temperature for 24 hours. Subsequently, the surface was wiped with water, soapy water, and ethanol in sequence, and the presence of any residue was observed. The degree of residue was graded from 1 to 5, with grade 5 indicating no residue and the best stain resistance.

[0082] For the chemical corrosion resistance test, refer to GB / T 3810.13-2016 Ceramic Tiles Test Methods Part 13: Determination of Chemical Corrosion Resistance. 3% hydrochloric acid solution (representing acidic cleaners), 3% potassium hydroxide solution (representing alkaline cleaners), and household bleach (representing chlorine-containing cleaners) are respectively added dropwise to the glaze surface. After covering, the surface is left for 24 hours. After cleaning, the glaze surface is observed for any corrosion marks. The corrosion resistance is classified into three levels: A, B, and C. Level A indicates no visible corrosion and excellent chemical corrosion resistance.

[0083] Regarding the Mohs hardness test, a Mohs hardness scratcher is used, and standard minerals (talc, gypsum, calcite, fluorite, apatite, orthoclase, quartz, topaz, corundum, diamond) are selected to scratch the glaze surface to determine the highest hardness level that the glaze surface can withstand.

[0084] The antibacterial ceramic sanitary ware products obtained in each embodiment and comparative example were evaluated according to the above test methods, and the results are summarized in Table 1.

[0085] Table 1. Comparison of antibacterial properties and durability between the embodiments and comparative examples.

[0086] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A long-lasting antibacterial glaze, characterized in that, Calculated by mass percentage, it includes 9-14% potassium feldspar, 28-35% quartz, 11-16% lithium low-expansion powder, 15-22% high-permeability frit powder, 8-14% calcite, 6-11% calcined kaolin, 4-8% talc, 0.5-2.5% zinc oxide, and 4-11% antibacterial powder.

2. The long-lasting antibacterial glaze as described in claim 1, characterized in that, The high-permeability frit powder, calculated by mass percentage, includes 58-62% silicon dioxide, 14-16% aluminum oxide, 6-8% calcium oxide, 2-4% magnesium oxide, 2-3% potassium oxide, 3-4% sodium oxide, and 3-4% zinc oxide.

3. The long-lasting antibacterial glaze as described in claim 1, characterized in that, The antibacterial powder is a silver-loaded zirconium phosphate antibacterial agent, wherein the silver oxide loading is 1.0-5.0 wt%, the particle size D50 is 1-10 μm, and the specific surface area is 5-15 m². 2 / g.

4. A method for preparing antibacterial ceramics using the long-lasting antibacterial glaze as described in claim 1, characterized in that, Includes the following steps: Step S1: Prepare ceramic blanks, perform high-pressure slip casting to form ceramic blanks, demold and dry them to obtain ceramic sanitary ware product blanks; Step S2: Apply long-lasting antibacterial glaze to the surface of the ceramic sanitary ware product body to form an antibacterial glaze coating; Step S3: After drying the ceramic sanitary ware body with the long-lasting antibacterial glaze coating, send it into the kiln for firing to obtain the finished ceramic sanitary ware body with long-lasting antibacterial function.

5. The method for preparing antibacterial ceramics as described in claim 2, characterized in that, In step S2, the long-lasting antibacterial glaze coating includes a base antibacterial-rich layer and a surface transparent protective layer. The surface transparent protective layer is applied on top of the base antibacterial-rich layer. The amount of antibacterial powder added to the base antibacterial-rich layer is 8-15%, and the glaze application rate is 250-300 g / m². 2 The transparent protective layer on the surface does not contain antibacterial powder, and the glaze application rate is 150-200g / m². 2 .

6. The method for preparing antibacterial ceramics as described in claim 2, characterized in that, In step S3, during the formal firing process, a first heat preservation zone and a second heat preservation zone are set. The first heat preservation zone is 850-950℃ and is maintained for 1-2 hours, while the second temperature zone is 1050-1150℃ and is maintained for 1.5-2.5 hours.

7. The method for preparing antibacterial ceramics as described in claim 2, characterized in that, In step S3, the fired ceramic sanitary ware product's main glaze surface is treated with a 5-10% hydrofluoric acid solution at a temperature of 80-100℃ for 30-60 seconds to micro-etch the ceramic sanitary ware product's main glaze surface, forming a nanoscale microporous structure on the glaze surface. A silver ion-containing impregnation solution is sprayed onto the activated ceramic sanitary ware product's main glaze surface and subjected to a penetration treatment under negative pressure for 10-30 minutes, allowing silver ions to penetrate into the glass network on the glaze surface through the micropores.

8. A ceramic sanitary ware product using the antibacterial ceramic preparation method as described in claim 4, characterized in that, The surface of the ceramic sanitary ware product has an antibacterial rate of ≥99% against Escherichia coli and Staphylococcus aureus, and the antibacterial rate remains ≥98% after durability testing.

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