In-situ self-assembled synergistically enhanced antibacterial self-cleaning composite ceramic glaze and preparation method thereof

Abstract

The present application relates to the technical field of ceramic glaze, and provides a kind of in-situ self-assembly synergistic reinforced antibacterial self-cleaning composite ceramic glaze and a preparation method thereof.The glaze comprises Si-Al glass network, TiO2 photocatalyst, Ag antibacterial agent and P and RE (rare earth) synergistic reinforcing agent.P and Ag form chemical anchoring to inhibit silver yellowing and achieve slow release, and the rare earth source is configured to effectively inhibit the excessive growth of titanium-containing crystal phase generated in-situ from the photocatalyst precursor, thereby ensuring high gloss of the glaze after firing.By introducing Li and using fast firing process, the contradiction between appearance and performance of multifunctional glaze is solved.The product has high whiteness, high gloss and persistent antibacterial self-cleaning function.

Description

Technical Field

[0001] This invention relates to the field of ceramic glaze technology, specifically to an in-situ self-assembled synergistically enhanced antibacterial and self-cleaning composite ceramic glaze and its preparation method. Background Technology

[0002] Ceramic glazes, as thin, glassy layers covering the surface of ceramic bodies, not only give products a smooth, glossy appearance but can also be functionally modified to possess special properties such as antibacterial and self-cleaning properties, meeting the growing demands for a healthy and convenient lifestyle. However, existing functional ceramic glaze technologies, while pursuing multifunctionality and high performance, generally face multiple irreconcilable contradictions, including functional durability, appearance quality, and compatibility with production processes.

[0003] In terms of achieving antibacterial function, existing technologies mainly focus on the application and improvement of silver-based antibacterial agents. Silver ions are widely used due to their broad-spectrum and highly effective antibacterial properties, but traditional silver-loaded glazes have significant drawbacks: silver is expensive; silver ions are easily reduced to metallic silver during high-temperature firing and long-term use, leading to yellowing or graying of the glaze surface, severely affecting its aesthetics; furthermore, the release of silver ions is often too rapid initially, making it difficult to match the antibacterial function with the long service life of ceramic products. To solve these problems, the industry has made many attempts. Chinese patent application CN110790505A, published on February 14, 2020, discloses a silver-free composite antibacterial ceramic glaze, which uses copper-loaded montmorillonite, zinc oxide, and nano-titanium dioxide as antibacterial components, aiming to reduce costs and avoid yellowing and potential safety risks caused by silver ions. While this technical approach solves some of the problems caused by silver, its antibacterial efficacy mainly relies on the contact release of ions, and the long-term durability of the function needs to be verified, and it does not involve photocatalytic self-cleaning function.

[0004] On the other hand, to improve the stability and long-lasting effect of silver-based antibacterial agents, subsequent research has focused on protecting the silver component through material composites and structural design. Chinese patent application CN117567029A, published on February 20, 2024, discloses an antibacterial ceramic glaze. This glaze uses a co-precipitation method to load silver and cerium onto the surfaces of alumina and antimony oxide, which are then sintered to form a functional glaze. In this system, antimony oxide acts as a welding material, aiming to form a composite phase at high temperatures to hinder the precipitation and ablation of silver, and to generate micropores through shrinkage during cooling to achieve the slow release of silver ions. This technology optimizes the high-temperature stability and release behavior of silver to some extent, but its preparation process is relatively complex (involving co-precipitation, sintering in a specific atmosphere, etc.), and to ensure functionality, some whiteness and gloss of the glaze may still need to be sacrificed. More importantly, none of the above-mentioned antibacterial glaze technologies have effectively integrated and solved the compatibility problem with photocatalytic self-cleaning functions.

[0005] In terms of achieving self-cleaning function, it usually relies on the introduction of photocatalysts such as titanium dioxide. However, TiO2 itself is a strong opacifier and crystallizer. When its addition reaches the level required for effective photocatalytic activity, it can easily lead to excessive crystallization of the glaze during firing, resulting in a rough, dull, or matte surface. This directly conflicts with the aesthetic requirements of modern high-end ceramic products for high gloss and a mirror-like finish.

[0006] The problem is exacerbated when attempting to simply combine antibacterial and self-cleaning functions. The introduction of multiple heterogeneous functional components can disrupt the uniformity and high-temperature rheological properties of the glaze system, increasing defects such as pinholes and bubbles. Furthermore, different components may interact adversely at high temperatures, ultimately leading to product deterioration and failure to achieve the expected functionalities.

[0007] Furthermore, many existing functional glaze preparation processes still rely on physical blending and slow firing, making them difficult to adapt to the efficient and energy-saving roller kiln fast-firing production lines of modern ceramics industry. How to simultaneously achieve good melting, leveling, degassing, and in-situ formation and stabilization of functional structures within a short fast-firing cycle is a significant technological challenge.

[0008] In summary, existing technologies have not yet provided a comprehensive solution to simultaneously achieve long-lasting antibacterial properties, highly efficient and stable photocatalytic self-cleaning properties, and maintain top-tier whiteness and gloss of the glaze under rapid firing conditions. Therefore, developing a novel composite functional ceramic glaze that can fundamentally overcome these multiple contradictions through the synergistic design of components and processes has become a pressing technical challenge in this field. Summary of the Invention

[0009] In view of the shortcomings of the prior art, the purpose of this invention is to provide an in-situ self-assembled synergistically enhanced antibacterial and self-cleaning composite ceramic glaze, fundamentally solving the inherent contradiction between antibacterial and self-cleaning functions and high whiteness and high gloss appearance. The product can simultaneously achieve L... It boasts a top-tier whiteness of ≥92, a mirror-like gloss of GU ≥85, and highly efficient multi-functionality.

[0010] Another objective of this invention is to provide a method for preparing an in-situ self-assembled synergistically enhanced antibacterial and self-cleaning composite ceramic glaze. Through the “Li-fast firing” synergistic design, a complex multifunctional glaze system can be perfectly adapted to the efficient and energy-saving roller kiln fast firing process, resulting in stable product quality, high yield, and strong industrial application value.

[0011] This invention is achieved using the following technical solution:

[0012] The in-situ self-assembled synergistically enhanced antibacterial and self-cleaning composite ceramic glaze, wherein the chemical composition of the glaze, by mass percentage of oxides, comprises: a) a glass network forming component: comprising SiO2 and Al2O3; b) a fluxing and modifying component: selected from at least one of alkali metal oxides, alkaline earth metal oxides, ZnO, and B2O3; c) a synergistic functional component, comprising:

[0013] i. Photocatalyst precursor: 0.5-6.0 wt% based on TiO2;

[0014] ii. Antimicrobial agent precursor: containing 0.005-0.2 wt% silver source based on Ag2O;

[0015] iii. Synergistic enhancer: comprising 0.05-0.6 wt% of a phosphorus source based on P2O5 and 0.05-1.0 wt% of a rare earth source based on RE2O3, wherein RE is selected from at least one of La and Y;

[0016] iv. Photocatalytic synergist: containing 0.001-0.05 wt% copper source based on CuO;

[0017] The phosphorus source is configured to work synergistically with the silver source during the sintering process to form phosphorus-rich coordination microregions in the glass phase, thereby enhancing the stability and migration barrier of silver ions by strengthening their coordination, thus effectively retaining silver and suppressing its coloration; the rare earth source is configured to suppress the excessive growth of the titanium-containing crystal phase generated in situ from the photocatalyst precursor.

[0018] Specifically, the above is a synergistic reaction system, rather than a simple physical mixture.

[0019] a) Glass network forming components (SiO2, Al2O3): These are the basis for the glass skeleton of the glaze and determine the basic physicochemical properties of the glaze surface, such as hardness and chemical stability.

[0020] b) Fluxing and modifying components (alkali metal / alkaline earth metal oxides, ZnO, B2O3): These components lower the melting temperature of the glaze, adjust its high-temperature viscosity and coefficient of thermal expansion, so that the glaze can be fired within a suitable temperature range and be well matched with the ceramic body.

[0021] c) Synergistic functional components: This is the core technology of the invention, comprising multiple synergistic sub-units:

[0022] i. Photocatalyst precursor (TiO2): This is the basis for achieving the photocatalytic self-cleaning function. During calcination, it precipitates a titanium-containing crystalline phase in situ. Its content range (0.5-6.0 wt%) is optimized to balance functionality and appearance.

[0023] ii. Antibacterial precursor (silver source): This is the foundation for achieving broad-spectrum antibacterial function. Silver is one of the most effective antibacterial elements, and its content range is strictly controlled to minimize the risk of discoloration while ensuring antibacterial efficacy.

[0024] iii. Synergistic enhancers (phosphorus source and rare earth source).

[0025] iv. Photocatalytic synergist: Contains a copper source of 0.001-0.05 wt% based on CuO.

[0026] The role of the phosphorus source (P2O5) is "chemical anchoring". It forms [PO4] structural units in the glass network, which can "capture" and "retain" silver ions through strong chemical bonding. This prevents silver ions from migrating and agglomerating at high temperatures to form yellow colloidal silver, and greatly slows down the release rate of silver ions, thus changing the antibacterial function from "short-term rapid effect" to "ultra-long-lasting".

[0027] The rare earth source (RE₂O₃, where RE is La or Y) acts as a "physical pinning" agent. Lanthanum (La) or yttrium (Y) ions accumulate at high temperatures on the surface of the precipitating titanium-containing crystalline phase, forming a "diffusion barrier." This physically hinders further grain growth, firmly controlling the grain size at the nanometer / submicron level without affecting light transmission. Thus, while achieving photocatalysis, the high gloss of the glaze is perfectly preserved. Rare earth ions (La) 3+ Y 3+ At high temperatures, these particles tend to accumulate at the interface of newly formed crystal phases. Alternatively, by increasing the viscosity of the glass melt and adding nucleation sites, the austenitic ripening process of the titanium-containing crystal phase can be effectively suppressed, keeping the grain size at the nanometer / submicron level where visible light scattering is minimal. This allows for both photocatalytic activity and the maintenance of a high-gloss glaze. Rare earth ions increase the nucleation density of the titanium-containing crystal phase and suppress crystal coarsening, keeping the grains at a low scattering scale, thus maintaining high gloss.

[0028] The copper source is configured to synergistically enhance the photocatalytic activity of the titanium-containing crystalline phase. The copper source acts as another synergistic enhancer. Its content is strictly limited to an extremely low range of 0.001-0.05 wt% to avoid its own coloring effect. At this concentration, copper's role is to synergistically improve photocatalytic efficiency with TiO2. Trace amounts of copper-related species (such as CuO or dissolved Cu) are also included. 2+ Efficient charge-trapping centers are formed at the interface between the titanium-containing crystalline phase and the glass phase, which can quickly capture photogenerated electrons and effectively suppress electron-hole pair recombination. Under visible light conditions, it exhibits a higher degradation rate of model pollutants, which is speculated to be related to the improved interface charge separation.

[0029] The glaze described is a type of glaze used for white-glazed high-gloss ceramic products. Its chemical composition has been further formulated to achieve a whiteness L measured on the glaze surface after firing under a D65 light source and a 10° field of view. ≥92.

[0030] To achieve the whiteness L ≥92, wherein the chemical composition contains 0.5-4.0 wt% TiO2 and 0.005-0.1 wt% Ag2O.

[0031] The rare earth source is configured to effectively suppress the excessive growth of the titanium-containing crystal phase generated in situ from the photocatalyst precursor, thereby ensuring that the 60° gloss of the glaze after firing is ≥85GU.

[0032] The fluxing and modifying components contain 0.1-1.5 wt% lithium source (based on Li₂O), which is configured to broaden the stable firing window of the glaze in the rapid firing process. Lithium is a highly efficient flux, but its core role here is as a "fine-tuner" for high-temperature viscosity. The introduction of trace amounts of lithium allows for a smoother viscosity change in the glaze within the critical firing temperature range (1150–1230°C), thus broadening the stability window of the rapid firing process. This ensures that the glaze has sufficient time to complete degassing, leveling, and stably form the desired functional microstructure even under harsh conditions of rapid heating and cooling, significantly improving the yield and stability of industrial production.

[0033] The phosphorus source is in the glass phase, where the phosphate structural units are associated with Ag. + It exhibits stronger coordination / binding effects, reducing the migration rate of silver in the glass network, thereby inhibiting reduction aggregation and coloration and achieving sustained release. Compared with the control group without the phosphorus source, it significantly improves the durability of antibacterial function. Silver ions are firmly bound in the glass network, and their sustained release behavior is chemically controlled, thus achieving ultra-long-lasting antibacterial function.

[0034] The in-situ self-assembled synergistically enhanced antibacterial and self-cleaning composite ceramic glaze described above has the following complete chemical composition by oxide mass percentage: SiO2: 40-65%; Al2O3: 8-18%; CaO+MgO: 5-15%; K2O+Na2O: 3-12%; ZnO: 0-8%; B2O3: 0-6%; Li2O: 0.1-1.5%; P2O5: 0.05-0.6%; TiO2: 0.5-6.0%; Ag2O: 0.005-0.2%; CuO: 0.001-0.05%; RE2O3: 0.05-1.0%. The chemical composition is calculated with the total of the listed oxides set at 100% and normalized. Unavoidable trace impurities (such as Fe2O3, MnO, etc.) are excluded.

[0035] The method for preparing the in-situ self-assembled synergistic enhanced antibacterial self-cleaning composite ceramic glaze adopts a roller kiln fast firing process under an oxidizing atmosphere, with a total firing cycle of 35-90 min and a maximum firing temperature of 1180-1300℃, preferably 1180-1240℃.

[0036] The peak temperature holding time of the aforementioned rapid firing process is 1-8 minutes, and includes an exhaust window in the 700-900℃ range and a functional self-assembly window in the 1050-1220℃ range. The functional self-assembly window (1050-1220℃) refers to the temperature range within which the glaze melt viscosity is moderate, ion diffusion ability is enhanced, and the following key physicochemical processes occur: the glaze surface is basically leveled, titanium-containing crystalline phases begin to nucleate and grow in large quantities, rare earth ions accumulate at grain boundaries, and silver ions achieve stable coordination in the phosphate structure microregions. The endpoint of this window is marked by the gloss reaching a plateau value and the grain size tending to stabilize.

[0037] The glaze of the present invention is made by melting or mixing various oxide raw materials in a specific ratio, and its final chemical composition, based on the mass percentage (wt%) of oxides, preferably falls within the range shown in Table 1:

[0038] Table 1: Raw materials for in-situ self-assembled synergistically enhanced antibacterial and self-cleaning composite ceramic glazes

[0039]

[0040] Note: Substitution of raw materials: In addition to lithium carbonate, lithium sources may also be lithium-containing minerals such as petalite and spodumene; in addition to aluminum dihydrogen phosphate, phosphorus sources may also be phosphates such as diammonium hydrogen phosphate and calcium phosphate that can be decomposed at high temperatures or incorporated into the glass network.

[0041] The present invention preferably employs a process of "co-milling of pre-melted blocks and functional powders" to obtain optimal dispersibility and reactivity.

[0042] (1) Preparation of pre-melted blocks:

[0043] Ingredients: Weigh all solid powder raw materials (i.e., raw materials that constitute the basic glass network, including lithium and phosphorus sources) except TiO2, Ag2O, CuO, and RE2O3 according to the formula, and mix them by dry ball milling for 1-3 hours.

[0044] Melting: Melt the mixture at 1400-1550℃ for 1-3 hours, and then quench it with water to make a basic frit.

[0045] (2) Preparation of the final glaze slurry:

[0046] Ingredients: Weigh the base frit obtained in step (1) and TiO2, Ag2O, CuO, and RE2O3 powders precisely in the proportions required for the chemical composition of the final product.

[0047] Wet ball milling: Add all the above solid materials, dispersant (0.1-0.5% of dry weight) and water (adjust solid content to 60-70%) to the ball mill and wet ball mill for 4-10 hours until the fineness of the glaze slurry is ≤0.3% when passing through a 325 mesh sieve.

[0048] Aging and Adjustment: Sift the glaze slurry to remove impurities and seal for aging for 12-48 hours. Before glazing, adjust the specific gravity to 1.60-1.80 g / cm³. 3 The viscosity should be adjusted to meet the construction requirements.

[0049] (3) Glazing and drying:

[0050] Apply the glaze evenly to the surface of the ceramic body, and control the thickness of the dry glaze layer to be 0.5-1.0 mm.

[0051] Dry at 80-120℃ until the moisture content is less than 1%.

[0052] (4) Firing (roller kiln fast firing process):

[0053] The glazed blanks are fed into the roller kiln, and the total firing cycle is 35–90 minutes.

[0054] Burning curve settings:

[0055] Exhaust window: in the 700-900℃ range, equivalent residence time is 2-6 minutes.

[0056] Peak temperature: 1180-1240℃.

[0057] Insulation time: Insulate at peak temperature for 1-8 minutes.

[0058] Functional self-assembly window: the entire rapid heating and heat preservation stage from 1050-1220℃.

[0059] Cooling: Controlled rapid cooling.

[0060] Specifically, at 700-900℃: carbonates decompose and release gas, and the glass phase begins to soften; Ag source decomposes / ionizes; P enters the glass to form phosphate structural units.

[0061] 1050-1220℃: Ti species precipitate into nanocrystalline phases; REs are enriched at grain boundaries / interfaces, inhibiting growth; Ag is bound by phosphate structures, reducing its mobility.

[0062] Cooling: Grain size is frozen; silver is mainly in ionic / coordination state, which inhibits the formation of metallic silver colloid.

[0063] To stably achieve L For a high whiteness of ≥92, the firing process should be carried out in an oxidizing atmosphere, with a slight positive pressure (10-30 Pa) maintained inside the kiln to prevent the entry of external reducing gases. The whiteness of the ceramic green body after firing should not be lower than 85. The aforementioned technical effects can be repeatedly obtained by employing the rapid firing process and preferred formulation range described in this invention. Ag source and glass frit are co-ball-milled, utilizing the high dispersibility of ball milling and the rapid heating characteristics of the rapid firing process, so that Ag is encapsulated by the phosphorus-rich glass phase before agglomeration.

[0064] P forms phosphorus-rich coordination microregions in the glass phase, enhancing Ag... + The coordination stability and migration barrier of Ag are reduced, thereby inhibiting Ag. 0 Aggregation and slow release are achieved. This not only fundamentally inhibits the migration and reduction yellowing of silver at high temperatures (ensuring whiteness), but also changes its release mode from rapid consumption to ultra-slow exchange, achieving ultra-long-lasting antibacterial function. Rare earth ions accumulate at the interface of titanium oxide grains at high temperatures, forming a physical barrier that hinders grain growth. This "locks" the size of the titanium-containing crystal phase at the nanoscale, enabling it to exert a highly efficient photocatalytic effect without scattering visible light, thus perfectly preserving the high gloss of the glaze while achieving self-cleaning function. The introduction of lithium finely regulates the high-temperature viscosity of the glaze, allowing it to smoothly degas and perfectly level even within the stringent time window of rapid firing. This provides a perfect macroscopic process platform for the stable occurrence of the above two microscopic synergistic effects, greatly improving the product yield and quality stability. Based on the above structure, trace amounts of copper, acting as "electron traps," significantly improve the degradation rate of model pollutants under visible light irradiation. This is presumably because trace amounts of copper species form effective charge-trapping centers at the interface between the titanium-containing crystalline phase and the glass phase, improving the separation efficiency of photogenerated carriers; while the slow-release system of silver complements the photocatalytic bactericidal function, forming an all-weather antibacterial barrier that is "highly efficient with light and without a light basis." The reactive oxygen species generated by photocatalysis may affect the valence state of surface silver, thus helping to maintain surface activity (not a necessary condition) and further extending the antibacterial lifespan. The synergistic formulation of this invention must be combined with a rapid calcination process. "Chemical anchoring" thermodynamically stabilizes silver ions, while rapid calcination shortens the migration / aggregation time window of Ag species in the high-temperature, low-viscosity stage, and, combined with the coordination stabilizing effect of the phosphorus-rich glass phase, reduces Ag... 0The probability of formation and growth are both indispensable, jointly ensuring the achievement of high whiteness. This invention couples a rapid firing process. The extremely rapid heating rate (≥40℃ / min) allows the glaze to quickly enter a molten state before Ag₂O decomposes and agglomerates into large particles of metallic silver. The molten phosphorus-rich glassy phase can promptly encapsulate, disperse, and fix silver ions, thereby kinetically "freezing" the ionic state of silver. This is the key to the synergistic inhibition of discoloration by the "formula + process". The antibacterial mechanism of this invention is mainly "contact sterilization (surface silver active sites)" + "photocatalytic assistance", rather than the traditional "massive ion leaching sterilization". The extremely low leaching amount is precisely the advantage of this invention - high safety (far below the drinking water silver limit of 50-100 ppb) and long-lasting efficacy.

[0065] Compared with the prior art, the beneficial effects of the present invention are:

[0066] (1) This invention fundamentally solves the inherent contradiction between antibacterial and self-cleaning functions and high whiteness and high gloss appearance. The product can simultaneously achieve L It boasts a top-tier whiteness of ≥92, a mirror-like gloss of GU≥85, and highly efficient composite functions. Through innovative "P-Ag chemical anchoring" technology, it achieves controllable and ultra-slow release of silver ions, making the effective period of antibacterial function comparable to the service life of ceramic products, and effectively inhibiting the problem of silver yellowing.

[0067] (2) Through the “RE-Ti physical pinning” technology, the size of the functional crystal phase is precisely controlled, ensuring high photocatalytic activity while maintaining the high gloss of the glaze, breaking through the bottleneck of traditional functional glazes that “lose gloss as soon as they are effective.” Through the “Li-fast firing” synergistic design, a complex multifunctional glaze system can be perfectly adapted to the efficient and energy-saving roller kiln fast firing process, resulting in stable product quality, high yield, and strong industrial application value. The synergistic effect of this invention is reflected in the dual control of thermodynamics and kinetics. The strong coordination of P-Ag thermodynamically stabilizes Ag. + The ionic state, coupled with the rapid firing process, kinetically shortens the time window for the migration, aggregation, and reduction of silver species in the high-temperature, low-viscosity melt. The synergistic effect of these two methods far surpasses that of either, jointly ensuring efficient silver retention and high whiteness of the glaze. Detailed Implementation

[0068] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0069] This invention provides an in-situ self-assembled synergistically enhanced antibacterial and self-cleaning composite ceramic glaze, wherein the chemical composition of the glaze, based on the mass percentage (wt%) of oxides, comprises:

[0070] SiO2: 40-65wt%

[0071] Al2O3: 8-18 wt%

[0072] CaO+MgO: 5-15wt%

[0073] K₂O + Na₂O: 3-12 wt%

[0074] ZnO: 0-8wt%

[0075] B2O3: 0-6wt%

[0076] Li2O: 0.1-1.5wt%

[0077] P2O5: 0.05-0.6wt%

[0078] TiO2: 0.5-6.0 wt%

[0079] Ag2O: 0.005-0.2wt%

[0080] CuO: 0.001-0.05wt%

[0081] RE2O3 (RE=La or Y): 0.05-1.0wt%;

[0082] The sum of the mass percentages of all the oxide components mentioned above is 100%.

[0083] In this invention, the composite ceramic glaze mainly consists of glass network forming and fluxing modification components, as well as synergistic functional components. The glass network forming and fluxing modification components constitute the glass matrix of the glaze. Preferably, the SiO2 content is 55wt%-62wt%; the Al2O3 content is 10wt%-15wt%; the total CaO+MgO content is 8wt%-12wt%, preferably, the mass ratio of CaO to MgO is (1:1)-(5:1); the total K2O+Na2O content is 4wt%-8wt%, preferably, the mass ratio of K2O to Na2O is (1:2)-(3:1). This invention does not have special restrictions on the source of the raw materials constituting these basic oxides; commercially available industrial-grade raw materials such as quartz, feldspar, kaolin, calcite, dolomite, zinc oxide, and boric acid, which are well known to those skilled in the art, can be used.

[0084] In this invention, the synergistic functional components are key to achieving the beneficial effects of the invention. Preferably, the Li₂O content is 0.2wt%-0.8wt%; the lithium source is preferably lithium carbonate or lithium feldspar. Preferably, the P₂O₅ content is 0.1wt%-0.4wt%; the phosphorus source is preferably aluminum dihydrogen phosphate powder or other phosphates that can form a glass network at high temperatures.

[0085] In this invention, the synergistic functional components further include photocatalytic, antibacterial, and performance-enhancing components. Preferably, the TiO2 content is 0.5wt%-4.0wt%; the titanium source is preferably rutile or anatase titanium dioxide. Preferably, the Ag2O content is 0.005wt%-0.1wt%; the silver source is preferably silver oxide or silver nitrate. Preferably, the CuO content is 0.001wt%-0.05wt%; the copper source is preferably copper oxide or basic copper carbonate. Preferably, the RE2O3 content is 0.1wt%-0.5wt%; the rare earth source is preferably lanthanum oxide (La2O3), yttrium oxide (Y2O3), or a mixture thereof, more preferably, when a mixture is used, the mass ratio of La2O3 to Y2O3 is (1:1)-(10:1). This invention does not impose special restrictions on the raw material sources of the above functional components; commercially available industrial-grade or chemically pure raw materials well known to those skilled in the art can be used.

[0086] This invention, through the precisely designed chemical composition, particularly the coupling effect of multiple synergistic functional components, enables in-situ crystallization and interfacial reactions during high-temperature firing, ultimately forming a composite functional glaze layer with highly optimized microstructure and superior macroscopic performance. The glaze not only possesses excellent antibacterial and self-cleaning properties, but more importantly, it fundamentally solves the core problems of traditional functional glazes, such as "functionality versus appearance" and "lack of durability."

[0087] The present invention also provides a method for preparing the composite ceramic glaze described above, preferably comprising the following steps:

[0088] a) The raw materials that constitute the basic glass network, including lithium and phosphorus sources, are mixed, melted at high temperature and quenched in water to prepare a pre-melted block;

[0089] b) The pre-melted block is wet-milled with functional powder containing titanium source, silver source, copper source and rare earth source to prepare the final composite functional glaze slurry.

[0090] In this invention, the temperature for high-temperature melting in step a) is preferably 1400℃-1550℃, and the time is preferably 1h-3h. The time for wet ball milling in step b) is preferably 4h-10h, until the fineness of the glaze slurry passes through a 325-mesh sieve and the residue is no more than 0.3%.

[0091] The preparation method provided by this invention, through the process of "pre-melted block + functional powder co-grinding", ensures the uniformity and stability of the basic glass network on the one hand, and enables the functional components with low heat sensitivity to be dispersed in the glaze slurry in a more uniform and fine manner on the other hand, laying the foundation for in-situ reaction and uniform phase formation in the subsequent firing process.

[0092] The present invention also provides a ceramic article using the above-mentioned glaze, comprising:

[0093] Ceramic body;

[0094] A functional glaze layer composited on the surface of the ceramic body;

[0095] The functional glaze layer is formed by firing the in-situ self-assembled synergistically enhanced antibacterial self-cleaning composite ceramic glaze described in the above technical solution.

[0096] In this invention, the ceramic body is preferably a sanitary ceramic body or a daily-use porcelain body. The functional glaze layer is applied to the surface of the body by methods well known to those skilled in the art, such as spraying, dipping, or glazing, and then formed by high-temperature firing. Preferably, the firing process is a roller kiln fast firing process, with a total firing cycle of 35-90 minutes and a maximum firing temperature of 1180℃-1240℃ (for sanitary ceramics) or 1250℃-1300℃ (for daily-use porcelain).

[0097] In this invention, the thickness of the functional glaze layer is preferably 0.5mm-1.0mm.

[0098] The composite ceramic glaze provided by this invention, through multiple synergistic effects, particularly the core mechanisms of "P-Ag chemical anchoring," "RE-Ti physical pinning," "Li-fast firing process window widening," and "Cu-Ti photocatalytic enhancement," results in ceramic products with outstanding beneficial effects. Its antibacterial properties are long-lasting and its self-cleaning function is highly efficient and stable. Simultaneously, the glaze maintains high whiteness, high gloss, and extremely low surface defects, perfectly adapting to modern, high-efficiency ceramic production methods.

[0099] All performance data mentioned in this specification were obtained through the following standardized testing methods.

[0100] 1. Appearance performance test

[0101] 1.1 Chromaticity (Lab) value)

[0102] Test instrument: X-RiteCi7600 benchtop spectrophotometer (X-Rite Corporation, USA).

[0103] Test standard: Based on GB / T11942-2015 "Method for measuring the colorimetry of colored building materials".

[0104] Test conditions:

[0105] Light source / observer: D65 standard light source / 10° standard observer.

[0106] Measurement mode: SCI (includes specular reflection) to reflect the overall color of the glaze.

[0107] Operating Procedure: Calibrate the instrument using a standard white board and black board. Select 5 test points without obvious defects on each 150x150mm sample board, measure them, and take the average value. The L value represents whiteness (100 is pure white), the a value represents red-green bias, and the b value represents the red-green bias. The value represents the yellow-blue bias.

[0108] 1.2 Specular Gloss (GU)

[0109] Testing instrument: BYK micro-TRI-gloss4520 three-angle gloss meter.

[0110] Test standard: Based on GB / T9754-2007 "Determination of 20°, 60° and 85° specular gloss of paint films without metallic pigments".

[0111] Test conditions:

[0112] Measurement angle: 60° measurement angle, suitable for medium to high gloss surfaces.

[0113] Operating procedure: Calibrate using the instrument's built-in standard calibration plate. Select 5 flat areas on each sample plate for measurement, and take the average value, in gloss units (GU).

[0114] 1.3 Surface defects

[0115] Test method: visual inspection, based on the company's internal standards, referring to JC / T2113-2012 "Requirements and Test Methods for Appearance Quality of Sanitary Ceramics".

[0116] Test conditions: Inside a standard light source box with an illuminance of 1000±200lx, the observation distance was 60cm and the observation angle was 45°.

[0117] Judgment criteria: Each piece is 225cm in length. 2 The total number of pinholes and bubbles with a diameter greater than 0.5 mm on the sample plate.

[0118] 2. Functional performance testing

[0119] 2.1 Antibacterial properties (antibacterial activity value R)

[0120] Test standard: Strictly in accordance with ISO22196:2011 "Measurement of antimicrobial activity of plastics and other nonporous surfaces" (equivalent to JISZ2801:2010).

[0121] Tested bacterial strains: Escherichia coli and Staphylococcus aureus.

[0122] Operating procedures:

[0123] Prepare 50x50mm test samples and blank control samples without antibacterial agents.

[0124] The bacterial suspension was dropped onto the sample surface and covered with a thin film.

[0125] Incubate for 24 hours at 35±1℃ and relative humidity ≥90%.

[0126] Wash off and count the number of viable bacteria.

[0127] Antibacterial activity value R = (U t -U0)-(A t -U0), where U t U0 is the logarithm of the blank sample after 24 hours of incubation, and A is the logarithm of the blank sample after 0 hours of incubation. t R is the logarithm value after 24 hours of incubation of the antibacterial sample. R ≥ 2.0 indicates a significant antibacterial effect.

[0128] 2.2 Antibacterial performance aging test

[0129] Test method: Self-developed simulated chemical cleaning and aging method.

[0130] Operating procedures:

[0131] The sample was immersed in an acetic acid solution with pH=4 and soaked at 30°C for 1 hour.

[0132] Remove the sample and rinse it thoroughly with deionized water.

[0133] The sample was immersed in a sodium hydroxide solution with pH=10 and soaked at 30°C for 1 hour.

[0134] Remove the sample and rinse it thoroughly with deionized water.

[0135] Repeat the above acid-base alternating soaking process for a total of 50 cycles.

[0136] The antibacterial activity value R of the aged sample was tested again according to the method in 3.1, and the antibacterial activity retention rate was calculated as (R after aging / initial R) × 100%.

[0137] Antibacterial performance test under illumination: Light source type: UVA-340 lamp; light intensity 1.0mW / cm² 2 .

[0138] Test standard: ISO27447:2019 Fine ceramics (advanced ceramics, advanced process ceramics) - Test method for antibacterial activity of semiconductor photocatalytic materials.

[0139] Test process:

[0140] Similarly, prepare samples and blank controls.

[0141] The bacterial suspension was dropped onto the sample surface and covered with a thin film that was transparent to ultraviolet light.

[0142] A group of samples was irradiated for a certain period of time under ultraviolet light (or simulated sunlight) of a specified intensity (UVA light intensity 1.0 mW / cm²). 2 Irradiation for 8 hours).

[0143] Another set of samples served as a dark control, and was placed in the dark at the same time as the light-illuminated group.

[0144] After irradiation, the viable bacteria were washed off and counted.

[0145] 2.3 Self-cleaning performance (photocatalytic degradation rate)

[0146] Test standard: Refer to ISO 10678:2010 Fine ceramics (advanced ceramics, advanced process ceramics) - Determination of the activity of semiconductor photocatalytic materials by methylene blue degradation under ultraviolet light irradiation.

[0147] Test conditions:

[0148] Model contaminant: 10 mg / L of methylene blue (MB) aqueous solution.

[0149] Light source: 300W xenon lamp equipped with a 420nm cutoff filter (filters out ultraviolet light and retains only visible light).

[0150] Light intensity: The light intensity measured at the sample surface was 200 ± 10 mW / cm². 2 .

[0151] Reactor: Place a 50x50mm sample in a petri dish and add 10mL of MB solution.

[0152] Operating procedures:

[0153] First, adsorb in the dark for 30 minutes to reach adsorption-desorption equilibrium.

[0154] Turn on the light source and irradiate for 60 minutes. The reaction is carried out in a constant temperature water bath, with the solution temperature controlled at 25±2℃ to eliminate thermal interference.

[0155] Take the supernatant and measure its absorbance at a wavelength of 664 nm using a UV-Vis spectrophotometer.

[0156] Degradation rate (%) = [(C0-C)] t ) / C0]×100%, where C0 and C t The values ​​are MB concentrations before and after irradiation (converted from absorbance).

[0157] To simulate real-world usage environments, additional testing was conducted under low-intensity visible light (1-5 mW / cm²). 2 The samples of this invention underwent long-term (24-168 hours) degradation tests under LED white light, and the samples also showed a sustained and effective ability to degrade pollutants.

[0158] 3. Application performance testing

[0159] 3.1 Abrasion resistance

[0160] Test standard: Based on GB / T3810.7-2016 "Test methods for ceramic tiles - Part 7: Determination of abrasion resistance of glazed tile surfaces".

[0161] Testing instrument: PEI abrasion tester.

[0162] Operating procedure: Use abrasives of different grit sizes to grind the glaze at a specified number of revolutions, observe and record the number of revolutions when visible wear appears on the glaze, and finally evaluate its wear resistance level (level 1 to level 5, with level 5 being the highest).

[0163] 3.2 Chemical corrosion resistance

[0164] Test standard: Based on GB / T3810.13-2016 "Ceramic tiles - Test methods - Part 13: Determination of chemical resistance".

[0165] Test reagents: 3% hydrochloric acid solution, 100g / L potassium hydroxide solution, and household cleaners and swimming pool salts (ammonium chloride 100g / L, sodium hypochlorite 20mg / L).

[0166] Operating procedure: After the reagent has been in contact with the sample surface for a specified time, clean it and observe whether there are any visible changes on the glaze. Assess the level (GA grade means no effect, GB grade means slight effect, etc.).

[0167] 3.3 Stain Resistance

[0168] Test standard: According to Appendix A (normative appendix) of GB / T6952-2015 "Sanitary Ceramics" anti-fouling test method.

[0169] Staining agent: A mixture of chromium oxide colorant and oil.

[0170] Operation process: Coat the contaminant agent on the surface of the sample. After a specified time, clean it successively with cleaning agents such as water, ethanol, and hydrochloric acid, observe the residual contaminants, and evaluate the grade (from grade 1 to grade 5, where grade 5 means it can be removed with water and has the best stain resistance).

[0171] 3.4 Thermal stability (thermal shock resistance)

[0172] Test standard: According to GB / T3810.9 - 2016 "Test methods for ceramic tiles - Part 9: Determination of thermal shock resistance".

[0173] Operation process: Repeatedly cycle the sample 10 times between an oven at 145 ± 5 °C and cold water at 15 ± 5 °C, with a residence time of 15 min each time. After taking it out, immerse it in methylene blue solution and observe whether cracks or peeling occur on the glaze surface. Passing is considered qualified.

[0174] Silver slow - release performance test (silver leaching amount)

[0175] Test standard: Refer to the test method for dissolution amount in GB4806.4 - 2016 "National food safety standard - Ceramic products", and make appropriate modifications to determine the silver leaching amount.

[0176] Operation process: Place a 50x50 mm sample in a beaker, add 4% (v / v) acetic acid solution as the immersion liquid, ensure that the glazed surface of the sample is completely immersed, and maintain the surface area / volume ratio (S / V) at 0.5 dm 2 / 100 mL. Immerse it in the dark at (22 ± 2) °C for 24 hours. After the immersion, take the immersion liquid and determine the silver ion concentration in the solution by inductively coupled plasma mass spectrometry (ICP - MS). The detection limit (LOD) of the instrument is 0.1 μg / L.

[0177] Color difference after aging (ΔE )

[0178] Test standard: The color difference calculation is based on the CIE1976L a b color space, in line with GB / T11942 - 2015. The aging process uses an acid - base cycling aging method.

[0179] To ensure the repeatability of the experiment, the sources and specifications of the main raw materials are as follows:

[0180] Quartz (SiO2): Fengyang Zhongyang Quartz Sand Co., Ltd., SiO2 ≥ 99.5%.

[0181] Potassium feldspar: Jiangxi Jiufeng Mining, high - potassium feldspar powder, K2O ≥ 11%.

[0182] Kaolin: Fujian Longyan Kaolin Co., Ltd., washed kaolin, Al2O3≥36%.

[0183] Calcite: Guangxi Guilin Guangyuan Chemical Co., Ltd., heavy calcium carbonate, CaCO3≥98%.

[0184] Zinc oxide (ZnO): Weifang Longda Zinc Industry Co., Ltd., indirect method 99.7%.

[0185] Boric acid (H3BO3): Yingkou Borda Fine Chemical Co., Ltd., analytical grade.

[0186] Lithium source: Industrial grade lithium carbonate (Li2CO3), purity ≥99.0%, d50≤5μm.

[0187] Phosphorus source: Industrial grade aluminum dihydrogen phosphate (Al(H2PO4)3): P2O5 content ≥45%, d50≤10μm.

[0188] Titanium dioxide (TiO2): Longbai Group Co., Ltd., rutile type, d50=0.3μm.

[0189] Copper oxide (CuO): Sinopharm Chemical Reagent Co., Ltd., analytical grade.

[0190] Silver oxide (Ag2O): Sinopharm Chemical Reagent Co., Ltd., analytical grade.

[0191] Rare earth source: Lanthanum oxide (La2O3): 99.9%, d50≤2μm.

[0192] Yttrium oxide (Y2O3): Jiangxi Jinshiji New Material Co., Ltd., 99.9%, d50=1.8μm.

[0193] Sodium feldspar: Foshan Xinshiwan Fine Arts Ceramics Factory Co., Ltd., Guangdong Province, sodium feldspar powder, Na2O≥9.5%, Fe2O3≤0.1%.

[0194] Preparation method of calcined kaolin:

[0195] The washed kaolin powder from Fujian Longyan Kaolin Co., Ltd. was selected and placed in a rotary kiln, where it was calcined at 750±50℃ for 2 hours to completely remove structural water. After cooling, it was pulverized by an air jet mill to a d90≤15μm to obtain calcined kaolin with low water absorption and high whiteness for later use.

[0196] In addition to lithium carbonate, lithium sources may also include lithium-containing minerals such as petalite and spodumene; in addition to aluminum dihydrogen phosphate, phosphorus sources may also include phosphates such as diammonium hydrogen phosphate and calcium phosphate that can be decomposed at high temperatures or incorporated into the glass network; in addition to lanthanum oxide, rare earth sources may also include yttrium oxide (Y2O3).

[0197] To ensure the glaze has a suitable firing temperature (1180-1240℃) and a coefficient of thermal expansion that matches the body (α≈6.5-7.5×10⁻⁶), -6 Those skilled in the art can routinely adjust the ratio of alkali metals, alkaline earth metals, ZnO, and B2O3. For example, they can lower the firing temperature by increasing the alkali metal / B2O3 content, or control crystallization and gloss by adjusting the alkaline earth / ZnO content.

[0198] Preparation of basic ingots:

[0199] Weighing: Accurately weigh all solid powder raw materials according to the raw material formula of each molten block in Table 2.

[0200] Mixing: Place the weighed raw materials in a V-type mixer and dry mix for 2 hours.

[0201] Melting and water quenching: The mixture is melted in a high-temperature electric furnace at 1450℃ for 2 hours, and then the glass melt is poured into circulating cooling water for water quenching to obtain glassy fragments.

[0202] Drying and Grinding: After drying the crushed material, it is coarsely crushed using a jaw crusher, and then pulverized using an air jet mill until d90 ≤ 20 μm to obtain the basic frit powder. To reduce phosphorus volatilization at high temperatures, the melting process can be carried out in a crucible with a cover, and the melting time at the highest temperature should be minimized. The theoretical oxide composition provided in this specification is a theoretical value calculated based on the amount of raw material input. In actual production, the amount of volatile components can be appropriately compensated according to the volatilization loss rate, for example, by overfeeding by 5-10%. As another optional implementation, the phosphorus source can also be added together with the functional powder during the ball milling stage of the final glaze slurry without adding the frit, and its uniform dispersion can be ensured by adjusting the ball milling parameters.

[0203] The basic frit raw material formula (parts by weight) is shown in Table 2.

[0204] The theoretical oxide composition of the basic melt is shown in Table 3.

[0205] Table 2: Basic Fused Ingot Raw Material Formulation (parts by weight)

[0206]

[0207] Table 3: Theoretical Oxide Composition of Basic Melt Block

[0208]

[0209] Example 1

[0210] Weighing: Accurately weigh the following raw materials to prepare 100g of dry material:

[0211] Basic frit A: 91.8g

[0212] Titanium dioxide (TiO2): 3g

[0213] Lanthanum oxide (La₂O₃): 0.17g

[0214] Silver oxide (Ag₂O): 0.02g

[0215] Copper oxide (CuO): 0.01g

[0216] Kaolin (for conditioning): 5g

[0217] Ball milling: Add 100.0g of dry material, 65g of water and 0.22g of sodium polyacrylate dispersant to a zirconia ball mill jar (ball-to-material ratio 2:1).

[0218] Grinding and testing: Wet ball milling was performed at 60 rpm for 8 hours. Samples were taken every 2 hours to test the fineness until the residue on a 325 mesh sieve was ≤0.2%.

[0219] Aging: After sieving, seal and age for 24 hours, adjusting the specific gravity to 1.75 g / cm³. 3 .

[0220] Glazing: Apply the aged glaze slurry to the surface of the dry sanitary ceramic blank using the spray glazing method, and control the thickness of the dry glaze layer to be 0.6-0.8mm.

[0221] Step 3: Firing (roller kiln fast firing process)

[0222] The glazed green body is then fed into an industrial roller kiln for firing. The firing process is strictly performed according to the synergistic rapid firing process described in this invention, with the specific parameters as follows:

[0223] Total firing cycle: 55 minutes.

[0224] Preheating and degassing stage: The billet undergoes a heating process of 700℃ to 900℃ (degassing temperature zone), and the time in this temperature zone is controlled to be 5 minutes.

[0225] Functional self-assembly stage: The total residence time of the billet in the temperature range above 1050℃ is controlled to be 12min.

[0226] Maximum firing temperature (peak): The maximum set temperature of the kiln is 1210℃.

[0227] Peak heat preservation time: The actual heat preservation time in the highest temperature zone of 1210℃ is 4 minutes.

[0228] Cooling: Afterwards, it enters the rapid cooling zone for quick cooling.

[0229] Examples 2-5: All used the same preparation steps as Example 1, except that the amount of functional components and kaolin used for conditioning in the final glaze slurry formulation was precisely calculated and adjusted according to the batch formulation of the final glaze slurry (Table 4), but the total dry material remained 1000.0g. The base frit A was still used.

[0230] Example 6: Batch formulation: Basic frit A: 91.84g;

[0231] Titanium dioxide (TiO2): 3.00g;

[0232] Yttrium oxide (Y₂O₃): 0.13 g;

[0233] Silver oxide (Ag₂O): 0.02g;

[0234] Copper oxide (CuO): 0.01g;

[0235] Kaolin (for conditioning): 5.00g.

[0236] Preparation process: Same as in Example 1.

[0237] Comparative Example 1: Using 92.00g of base frit B, the batch formulation of the glaze slurry is shown in Table 4, and the preparation steps are the same as in Example 1.

[0238] Comparative Example 2: 91.97g of base frit A was used, but 0.17g of La2O3 was not added; instead, 0.17g of kaolin was used. The batch formulation of the glaze slurry is shown in Table 4, and the rest is the same as in Example 1.

[0239] Comparative Example 3: Using 1.80 g of base frit C9, the batch formulation of the glaze slurry is shown in Table 4, and the preparation steps are the same as in Example 1.

[0240] Comparative Example 4: Using 100g of basic frit D, without adding any functional components. The batch formulation of the glaze slurry is shown in Table 4, and the rest is the same as in Example 1.

[0241] Comparative Example 5: 91.81g of base frit A was used, but 0.01g of CuO was not added. The batch formulation of the glaze slurry is shown in Table 4, and the rest is the same as in Example 1.

[0242] Comparative Example 6: The same glaze slurry as in Example 1 was used, but the following tunnel kiln "slow firing process" was employed for firing;

[0243] Total cycle time: 600 minutes.

[0244] Exhaust temperature zone (700-900℃) transit time: 50 min.

[0245] Maximum temperature: 1210℃.

[0246] Peak heat preservation time: 30 minutes.

[0247] Cooling: The furnace cools naturally.

[0248] Comparative Example 7: Batch Formulation:

[0249] Basic frit E: 91.80g;

[0250] Titanium dioxide (TiO2): 3.00g;

[0251] Lanthanum oxide (La₂O₃): 0.17 g;

[0252] Silver oxide (Ag₂O): 0.02g;

[0253] Copper oxide (CuO): 0.01g;

[0254] Kaolin (for conditioning): 5.00g;

[0255] Preparation process: Same as in Example 1.

[0256] The batch formulations of the glaze slurries for Examples 1-6 and Comparative Examples 1-7 are shown in Table 4.

[0257] The final chemical compositions of Examples 1-6 and Comparative Examples 1-7 are shown in Table 5.

[0258] The test data for Examples 1-6 and Comparative Examples 1-7 are shown in Table 6.

[0259] Table 4: Batch formulations (parts by weight) of glaze slurries for Examples 1-6 and Comparative Examples 1-7

[0260]

[0261] Table 5: Final chemical composition of Examples 1-6 and Comparative Examples 1-7

[0262]

[0263] Table 6: Test data of Examples 1-6 and Comparative Examples 1-7

[0264]

[0265] As shown in Table 4-6, in Comparative Example 1, b The value was significantly higher than that of Example 1, indicating that silver underwent more severe yellowing at high temperatures due to the lack of phosphorus fixation. More importantly, after aging, its antibacterial activity value R plummeted from >3.0 to 1.5, with a retention rate of less than 50%, while Example 1 maintained over 95%. This irrefutably proves that P2O5, through chemical anchoring, simultaneously solves the two core pain points of silver: "coloring" and "short-lived effect." The leaching amount in Example 1 was much lower than that in Comparative Example 1, directly demonstrating the "chemical anchoring" effect of phosphorus. The color difference in Example 1 was much smaller than that in Comparative Examples 1 and 6, proving that "P-Ag anchoring" and "rapid firing process" synergistically suppressed the coloring effect of silver.

[0266] The gloss of Comparative Example 2 was significantly lower than that of Example 1. This was mainly due to the lack of rare earth elements to inhibit the growth of the titanium-containing crystal phase, resulting in grain coarsening and enhanced light scattering. Although the substitution of kaolin may have a slight impact on the melting characteristics of the glaze, such a significant difference in gloss is mainly attributed to the uncontrolled crystal size, which directly demonstrates the crucial role of rare earth elements.

[0267] The number of pinholes in Comparative Example 3 increased significantly, and the process window narrowed. This is mainly due to the lack of Li2O, a highly efficient flux and viscosity modifier, in the formulation. Additionally, changes in the alkali metal ratio may have led to a steeper high-temperature viscosity curve for the glaze. Under the harsh conditions of rapid firing, this high viscosity or narrow suitable viscosity range is detrimental to bubble escape and glaze leveling, resulting in increased defects. This conversely demonstrates the importance of introducing Li2O into the formulation of this invention for adapting to rapid firing processes and ensuring product yield.

[0268] Example 1 showed an antibacterial activity value R > 5.5 under light irradiation, while Comparative Example 4 showed almost 0. This demonstrates that the functional component system (Ag+Ti+Cu) of the present invention endows the product with strong photocatalytic antibacterial ability.

[0269] The photocatalytic MB degradation rate of Comparative Example 5 was significantly lower than that of Example 1. This demonstrates that even an extremely low concentration of copper (0.01 wt%) can act as a highly efficient "electron trap," significantly inhibiting the recombination of TiO2 photogenerated carriers, thereby improving the photocatalytic efficiency by nearly 30%. Example 1 had an R value > 5.5, while Comparative Example 5 had an R value of only 4.2. Both examples contained Ag and Ti, and exhibited similar antibacterial abilities in the dark. However, under illumination, Example 1, containing trace amounts of Cu, showed a significantly stronger bactericidal effect. This strongly suggests that Cu enhances photocatalytic antibacterial ability by improving photocatalytic efficiency.

[0270] Comparative Example 6: Appearance and performance deteriorated across the board: b The gloss value spiked to 3.5, the gloss plummeted to 78, and the number of pinholes increased dramatically. This indicates that the slow-burning process led to excessive growth and coarsening of the titanium-containing crystal phase, resulting in severe light scattering and loss of gloss. Fast burning is crucial for suppressing silver yellowing. Rapid passage through the high-temperature zone shortens the reduction and migration time of silver. Fast burning is also essential for maintaining high gloss. Short-term heat preservation effectively inhibits the growth of the titanium-containing crystal phase. Fast burning combined with a lithium-containing formulation is crucial for controlling defects. This demonstrates that the optimal effect can only be achieved by combining the "synergistic formulation" and the "fast-burning process" of this invention; neither can be dispensed with, representing a typical example of synergistic innovation in formulation and process. Comparative Example 4, while having the best appearance, completely lacks functionality. This conversely proves the effectiveness of the functional system of this invention and highlights that Example 1 achieves powerful composite functionality with only minimal sacrifice in appearance indicators, demonstrating extremely high cost-effectiveness.

[0271] Comparative Example 7 employed a base glaze system completely devoid of ZnO and B2O3, using increased alkali metal and alkaline earth content for fluxing. Despite significant differences in its base formulation, it still exhibited excellent overall performance after incorporating the core synergistic functional components of this invention. Although its appearance index (L... b The GU content was slightly lower than that of Example 1 using the ZnO-B2O3 system, but its core functions and synergistic mechanisms were successfully reproduced.

[0272] In summary, the embodiments of the present invention, through comparison with a series of targeted comparative examples, clearly and powerfully demonstrate, from both data and mechanism perspectives, the existence of multiple synergistic effects such as P-Ag, RE-Ti, Li-fast burning, and Cu-Ti, and the significant technical advantages they bring, fully supporting the inventiveness and advancement of the present invention.

[0273] To verify the practical application effects of the glaze described in this invention on different ceramic products and to compare it with existing technologies, the following application examples are provided. All application examples will uniformly use the glaze from Example 1, which has been proven to be the optimal solution. The comparative examples will not repeat the verification of the synergistic effects of the components (such as P, RE, Li, Cu) and processes (rapid firing) within this invention, but will directly compare its performance with that of traditional functional glazes that simulate current mainstream market technologies.

[0274] Preparation of ceramic green body

[0275] (1) Preparation of sanitary ceramic blanks

[0276] Main component formula of billet (parts by weight):

[0277] Kaolin (Guangxi): 30 samples

[0278] Soil ball (Hunan): 20 parts

[0279] Potassium feldspar: 28 parts

[0280] Quartz: 22 samples

[0281] Preparation method:

[0282] Weigh the raw materials according to the formula, add appropriate amounts of water and electrolytes (water glass, sodium carbonate), and wet ball mill in a ball mill for 12 hours to make a slurry.

[0283] The mud is sieved to remove iron and then vacuum-kneaded to produce plastic mud segments.

[0284] A 100x100mm sample plate was made using a high-pressure grouting molding process and dried at 110℃ for 24 hours.

[0285] The dried body is then bisque-fired at 850℃ for 1 hour. This yields a bisque-fired sanitary ceramic body ready for glazing.

[0286] (2) Preparation of high-strength daily-use porcelain blanks

[0287] Main component formula of billet (parts by weight):

[0288] Calcinated kaolin: 20 parts

[0289] Kaolin: 25 parts

[0290] Nepheline syenite: 20 samples

[0291] Feldspar: 15 portions

[0292] Quartz: 15 pieces

[0293] Alumina micro powder (α-Al2O3, d50=2μm): 5 parts

[0294] Preparation method:

[0295] The process flow is similar to that for preparing sanitary ceramic blanks, also employing wet ball milling and vacuum clay refining.

[0296] A circular sample tray with a diameter of 150 mm was made using an isostatic pressing process and dried at 110℃.

[0297] This body will be fired in one firing process, that is, it will be fired at high temperature directly after glazing.

[0298] Glazes used in application examples and comparative examples

[0299] Application Example 1 (Sanitary Ware): The glaze is directly prepared using the glaze slurry from Example 1 above.

[0300] Application Example 2 (High-strength Daily Porcelain): The glaze is directly prepared using the glaze slurry from Example 1 above.

[0301] Application Comparative Example 1 (Copper-free solution of the present invention / satellite porcelain): The glaze is directly prepared using the glaze slurry of the aforementioned Comparative Example 5 (Cu-free).

[0302] Application Comparative Example 2 (Slow-firing scheme of the present invention / Waist porcelain): The glaze material is directly the glaze slurry prepared in the aforementioned Comparative Example 6 (slow-firing).

[0303] Glazing and firing processes

[0304] Application of sanitary ceramics (Application Example 1, Application Comparative Example 1, Application Comparative Example 2):

[0305] Each glaze slurry was sprayed onto the bisque-fired sanitary ceramic body, with a dry glaze thickness of 0.7 mm.

[0306] Application Example 1 and Comparative Example 1 both adopted the aforementioned rapid firing process.

[0307] Comparative Example 2 strictly followed the aforementioned slow-cooking process.

[0308] Application of high-strength daily-use ceramics (Application Example 2):

[0309] Each glaze slurry was sprayed onto the dry raw porcelain body, with a dry glaze thickness of 0.6 mm.

[0310] The roller kiln uses a single-firing process with a total cycle of 90 minutes, a maximum temperature of 1280℃, and a holding time of 5 minutes.

[0311] The test data for Application Examples 1-2 and Application Comparative Examples 1-2 are shown in Table 7.

[0312] Table 7: Test data for Application Examples 1-2 and Comparative Examples 1-2

[0313]

[0314] As shown in Table 7, the photocatalytic degradation rate of Comparative Example 1 was significantly lower than that of Application Example 1. This further demonstrates at the practical product level that even with the presence of the remaining synergistic systems of this invention, the introduction of trace amounts of copper remains necessary to optimize self-cleaning efficiency. Comparative Example 2 exhibited disastrous appearance defects (severe yellowing, loss of gloss, and numerous pinholes) in actual sanitary ceramic products. Although its functionality was acceptable, it was completely unqualified as a commercial product. This irrefutably proves that the synergistic formulation of this invention, combined with the rapid firing process, is essential to achieving its inventive purpose: to impart functionality while maintaining a superior appearance.

Claims

1. An in-situ self-assembled synergistically enhanced antibacterial self-cleaning composite ceramic glaze, characterized in that, The chemical composition of the glaze, by mass percentage of oxides, comprises: a) a glass network forming component: comprising SiO2 and Al2O3; b) a fluxing and modifying component: selected from at least one of alkali metal oxides, alkaline earth metal oxides, ZnO, and B2O3; c) a synergistic functional component, comprising: i. Photocatalyst precursor: 0.5-6.0 wt% based on TiO2; ii. Antimicrobial agent precursor: containing 0.005-0.2 wt% silver source based on Ag2O; iii. Synergistic enhancer: comprising 0.05-0.6 wt% of a phosphorus source based on P2O5 and 0.05-1.0 wt% of a rare earth source based on RE2O3, wherein RE is selected from at least one of La and Y; iv. Photocatalytic synergist: containing 0.001-0.05 wt% copper source based on CuO; The phosphorus source is configured to work synergistically with the silver source during the sintering process to form phosphorus-rich coordination microregions in the glass phase, thereby enhancing the stability and migration barrier of silver ions by strengthening their coordination, thus effectively retaining silver and suppressing its coloration; the rare earth source is configured to suppress the excessive growth of the titanium-containing crystal phase generated in situ from the photocatalyst precursor. The glaze described is a type of glaze used for white-glazed high-gloss ceramic products. Its chemical composition has been further formulated to achieve a whiteness L measured on the glaze surface after firing under a D65 light source and a 10° field of view. ≥92; The rare earth source is configured to effectively suppress the excessive growth of the titanium-containing crystal phase generated in situ from the photocatalyst precursor, thereby ensuring that the 60° gloss of the glaze after firing is ≥85GU. The fluxing and modifying components contain 0.1-1.5 wt% lithium source based on Li2O, and the lithium source is configured to broaden the stable firing window of the glaze in the fast firing process; The in-situ self-assembled synergistically enhanced antibacterial and self-cleaning composite ceramic glaze has the following complete chemical composition by oxide mass percentage: SiO2: 40-65%; Al2O3: 8-18%; CaO+MgO: 5-15%; K2O+Na2O: 3-12%; ZnO: 0-8%; B2O3: 0-6%; Li2O: 0.1-1.5%; P2O5: 0.05-0.6%; TiO2: 0.5-6.0%; Ag2O: 0.005-0.2%; CuO: 0.001-0.05%; RE2O3: 0.05-1.0%.

2. The in-situ self-assembled synergistically enhanced antibacterial self-cleaning composite ceramic glaze according to claim 1, characterized in that, To achieve the whiteness L ≥92, wherein the chemical composition contains 0.5-4.0 wt% TiO2 and 0.005-0.1 wt% Ag2O.

3. A method for preparing the in-situ self-assembled synergistically enhanced antibacterial self-cleaning composite ceramic glaze according to claim 1 or 2, characterized in that, This method employs a roller kiln rapid firing process under an oxidizing atmosphere, with a total firing cycle of 35-90 minutes and a maximum firing temperature of 1180-1300℃.

4. The preparation method of the in-situ self-assembled synergistically enhanced antibacterial self-cleaning composite ceramic glaze according to claim 3, characterized in that, The peak temperature holding time of the rapid heating process is 1-8 minutes, and it includes an exhaust window in the range of 700-900℃ and a functional self-assembly window in the range of 1050-1220℃.

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