Medium-gloss super-antifouling glaze based on dual-network regulation and control, preparation method thereof and ceramic tile

Abstract

The invention relates to the technical field of ceramic glazes, and discloses a medium-gloss super-antifouling glaze based on dual-network regulation, a preparation method thereof and a ceramic tile wherein the chemical composition of the medium-gloss super-antifouling glaze comprises, by mole, 45-60% of SiO2, 10-25% of Al2O3, and 15-32% of the total molar weight of an alkaline earth metal network forming agent, and the ratio of (CaO + MgO) / (BaO + ZnO) is (0.8-1.5): 1; the total molar weight of the network modifier is 0.5-3.5%, and the ratio of SrO to Li2O is (0.2-5): 1; the total content of K2O and Na2O is 1-4%. A nano split-phase structure is formed through induction of a specific proportion of the alkaline earth metal network forming agent, and the split-phase interface energy and stability are finely adjusted through cooperative regulation and control of the SrO / Li2O network modifier, so that the technical problem that super-strong antifouling property and high permeability of a glaze surface are difficult to consider under the medium glossiness of 25-45 GU is successfully solved; and the obtained glaze has silky soft gloss, fine touch feeling and excellent chemical corrosion resistance and hardness, and is suitable for production of high-quality ceramic tiles.

Description

Technical Field

[0001] This invention relates to the field of ceramic glaze technology, and in particular to a medium-gloss, ultra-foul-resistant glaze based on dual-network regulation, its preparation method, and ceramic bricks. Background Technology

[0002] As a primary building decoration material, the texture and function of the glaze layer on ceramic tiles directly affect the product's aesthetic value and practical performance. In recent years, the consumer market's demand for glaze textures has become increasingly refined and diversified. Between the vibrancy of glossy glazes and the simplicity of traditional matte glazes (whose gloss level is typically below 15°), glazes with a silky, soft visual feel have gained favor in the high-end market.

[0003] Ideal modern glazes should possess the following characteristics: 1) A soft and uniform luster with no glare, creating a comfortable and tranquil atmosphere; 2) A delicate and warm touch with a silky smooth feel; 3) Extremely high surface density, providing excellent resistance to stubborn stains such as oil-based pens, coffee, and soy sauce in daily life (i.e., super stain-resistant); 4) Good light transmittance, enabling digital inkjet decorative patterns under the glaze to be clear, vibrant, and layered (i.e., high transparency); 5) Good physical and chemical properties such as wear resistance and chemical corrosion resistance.

[0004] However, existing glaze systems struggle to simultaneously achieve properties 3) and 4) within a medium gloss range (e.g., 25-45 degrees, a range brighter than traditional matte glazes and softer than glossy glazes, considered the most visually comfortable and easily integrated with various decorating styles). This creates an irreconcilable contradiction between superior stain resistance and high transparency. The root of this contradiction lies in the glaze's microstructure. Stain resistance relies on the high vitrification of the glaze layer, forming a continuous, dense, and smooth amorphous glass network that prevents stains from penetrating. Conversely, achieving a soft, non-mirror-like gloss requires the introduction of appropriate light-scattering centers. Traditional technical approaches mainly involve two methods: one is to promote the precipitation of microcrystals (e.g., CN112279516A), reducing gloss through crystal scattering, but this significantly increases the opacity of the glaze, severely sacrificing transparency and making the pattern appear hazy; the other is to increase the Al2O3 / SiO2 ratio in the glaze formula or use high-melting-point components to increase high-temperature viscosity, resulting in incomplete vitrification of the glaze and a rough surface with scattering. However, this directly damages the density and smoothness of the glaze, leading to decreased stain resistance, a narrow process control window, and poor product stability.

[0005] Existing technologies have failed to provide an effective solution to simultaneously achieve the highest level (≥4 level) of stain resistance and superior visual transparency (transmittance ≥60%) at a medium gloss level of 25-45 GU. Therefore, there is an urgent need in the field for an innovative glaze design principle and preparation method that can overcome the aforementioned performance barriers through precise composition design and structural control, and produce a new generation of ceramic tiles with excellent comprehensive performance. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing a medium-gloss, ultra-stain-resistant glaze based on dual-network regulation, and ceramic tiles thereof, aiming to solve the problem that the existing technology is unable to achieve a medium gloss range of 25-45 GU, so that the glaze surface simultaneously has super stain resistance and excellent light transmittance, as well as good glaze surface hardness and chemical stability.

[0007] The technical solution of the present invention is as follows: A medium-gloss, ultra-foul-resistant glaze based on dual-network regulation, wherein, based on the total molar amount of the glaze's chemical composition after firing (100%), the chemical composition comprises: SiO2: 45-60 mol% Al2O3: 10-25 mol% Alkaline earth metal network forming agent, composed of CaO, MgO, BaO and ZnO, and satisfying the ratio of the total molar amount of CaO and MgO to the total molar amount of BaO and ZnO is 0.8-1.5:1; The network modifier is composed of SrO and Li2O, and the molar ratio of SrO to Li2O is 0.2-5:1. The total molar content of K2O and Na2O is 1-4 mol% The total molar amount of the alkaline earth metal network forming agent is 15-32 mol, and the total molar amount of the network modifier is 0.5-3.5 mol.

[0008] The medium-gloss, anti-fouling glaze based on dual-network regulation has a molar ratio of CaO and MgO to BaO and ZnO of 1-1.3:1.

[0009] The medium-gloss, ultra-fouling glaze based on dual-network regulation has a molar ratio of SrO to Li2O of 0.5-2:1.

[0010] The medium-gloss, ultra-foul-resistant glaze based on dual-network regulation has a total molar amount of 1-2.5 mol of network modifier.

[0011] The medium-gloss, ultra-foul-resistant glaze based on dual-network regulation has a molar ratio of K2O to Na2O of 1.5-4:1.

[0012] The medium-gloss, ultra-foul-resistant glaze based on dual-network regulation, wherein the glaze surface fired from the glaze with the aforementioned chemical composition has a 60° gloss of 25-45 GU.

[0013] A method for preparing a medium-gloss, super-fouling glaze based on dual-network regulation as described in this invention, comprising the following steps: S1. Raw material conversion and batching: Based on the chemical composition and the relationship between each oxide, select mineral raw materials and chemical raw materials containing the required elements for weighing. Among them, SrO is introduced by strontium carbonate, and Li2O is introduced by spodumene and / or lithium carbonate. S2. Mixing and ball milling: Mix the prepared raw materials with water and wet ball mill until the glaze slurry has a fineness of 0.05-0.3% residue on a 10,000-mesh sieve and a specific gravity of 1.86-1.92. S3. Glazing and firing: The glaze is applied to the surface of the ceramic body and fired once at a temperature of 1180-1220℃.

[0014] A ceramic tile, wherein the surface is coated with a medium-gloss, ultra-foul-resistant glaze based on dual-network regulation as described in this invention.

[0015] Beneficial Effects: This invention proposes a medium-gloss, ultra-foul-resistant glaze based on dual-network regulation. Alkaline earth metal network forming agents (CaO, MgO, BaO, ZnO) are responsible for establishing the main framework of the glaze's microstructure; network modifiers (SrO, Li2O) are responsible for finely adjusting and stabilizing the main framework. Through a specific molar ratio and content synergistic effect, the two guide the glaze to form an ideal nano-phase structure during firing, rather than the traditional large-size crystal precipitation. This achieves a breakthrough in the performance balance of the medium-gloss, ultra-foul-resistant glaze: successfully achieving a stain resistance level ≥4 (mostly level 5) and a light transmittance ≥60% simultaneously and stably at a medium gloss level of 25-45 GU. This performance combination completely breaks the traditional perception that medium-gloss glazes must compromise on stain resistance or transparency. Attached Figure Description

[0016] Figure 1 The present invention provides a flowchart of a method for preparing a medium-gloss, super stain-resistant glaze based on dual-network regulation.

[0017] Figure 2 This is a photograph of a ceramic tile made using the glaze from Example 1 of this invention.

[0018] Figure 3 This is a photograph of a ceramic tile made using the glaze from Example 2 of this invention.

[0019] Figure 4 This is a photograph of a ceramic tile made using the glaze from Example 3 of this invention. Detailed Implementation

[0020] This invention provides a medium-gloss, ultra-fouling glaze based on dual-network regulation, its preparation method, and ceramic tiles. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0021] This invention provides a medium-gloss, ultra-foul-resistant glaze based on dual-network regulation, characterized in that, based on the total molar amount of the glaze's chemical composition after firing (100%), the chemical composition comprises: SiO2: 45-60 mol% Al2O3: 10-25 mol% Alkaline earth metal network forming agent, composed of CaO, MgO, BaO and ZnO, and satisfying the ratio of the total molar amount of CaO and MgO to the total molar amount of BaO and ZnO is 0.8-1.5:1; The network modifier is composed of SrO and Li2O, and the molar ratio of SrO to Li2O is 0.2-5:1. The total molar content of K2O and Na2O is 1-4 mol% The total molar amount of the alkaline earth metal network forming agent is 15-32 mol, and the total molar amount of the network modifier is 0.5-3.5 mol.

[0022] Specifically, in this embodiment, SiO2 (45-60 mol%) and Al2O3 (10-25 mol%) mainly serve as the network framework forming bodies of the glaze. SiO2 is the basic forming body of the glass network, forming a three-dimensional spatial network framework in the form of [SiO4] tetrahedra, which endows the glaze with high-temperature viscosity, chemical stability and mechanical strength. Al2O3 is the network intermediate, which usually partially replaces [SiO4] in the silicon-oxygen network in the form of [AlO4] tetrahedra, playing a role in network supplementation and significantly improving the chemical stability, hardness and high-temperature viscosity of the glaze. Together, they constitute the framework of the glaze.

[0023] In this embodiment, if the SiO2 content is less than 45 mol%, the network skeleton is too weak, the glaze is prone to cracking, and the chemical durability is poor; if it is more than 60 mol%, the glaze is difficult to melt, requiring a higher firing temperature, and the high-temperature viscosity is too high, which easily leads to uneven glaze surface; if the Al2O3 content is less than 10 mol%, the glaze surface hardness is insufficient and the chemical stability is poor; if it is more than 25 mol%, the glaze is difficult to melt, which easily leads to glaze surface opacity and roughness, seriously damaging transparency and gloss.

[0024] In this embodiment, alkaline earth metal network forming agents (CaO, MgO, BaO, ZnO) are the core regulating agents for achieving the nanoscale phase separation structure in this invention. As network modifiers, they enter the interstices of the silicon-aluminum network, breaking Si-O-Si bonds and providing free oxygen, thereby reducing melt viscosity and melting temperature. Specifically, CaO and MgO have higher ionic field strength (Z / r). 2 Larger molecules bind more strongly to oxygen ions, resulting in a relatively mild effect on network breakage. This tends to lead to a relatively compact melt structure and promotes the formation of high-viscosity, silicon-rich phases in phase separation. BaO and ZnO: Ba 2+ With a large ionic radius and weak field strength, Zn exerts a strong disruptive effect on the network, significantly reducing viscosity. 2+ It is amphoteric and is often used as a network modifier in glazes, but it can also enter the network. It usually plays a strong role in fluxing and reducing high-temperature viscosity, and promotes the formation of low-viscosity, alkaline earth metal phases in phase separation.

[0025] When two groups of ions with opposing effects coexist in a specific ratio R1 = 0.8-1.5:1, their polymerization and depolymerization effects on the network structure in the high-temperature melt reach a dynamic competitive equilibrium. This competition thermodynamically reduces the stability of the homogeneous single-phase melt, thereby inducing Spinodal decomposition or nucleation-growth type liquid-liquid phase separation, spontaneously forming a two-phase structure with periodically modulated composition at the nanoscale. This is the structural basis for obtaining a soft luster and high transparency. Preferably, when R1 = 1.0-1.3:1, the competition is most balanced, resulting in the most uniform phase-separated structure with the most suitable size, soft scattering, good light transmittance, and dense bonding at the two-phase interface. If the ratio deviates from this range, the competition becomes unbalanced: for example, when R1 < 0.8, the BaO / ZnO effect is too strong, the network breaks severely, the glaze is over-vitrified, pinholes are easily formed, the gloss is too high (>50GU), and the phase separation tendency is weak; if the ratio is higher than 1.5, the CaO / MgO effect is too strong, which easily promotes the precipitation of micron-sized crystals such as diopside (CaMgSi2O6) and wollastonite (CaSiO3), resulting in a cloudy glaze surface (poor transparency), a rough feel, and the crystal boundaries may become channels for stains to penetrate (reduced stain resistance).

[0026] In this embodiment, the network modifier (SrO, Li2O) is the innovative synergistic stabilizer of the present invention, wherein SrO contains Sr 2+ The ionic radius (1.18 Å) is between that of Ca. 2+ (1.00 Å) and Ba 2+ The electric field strength is also moderate between (1.35 Å), and the introduction of SrO can partially replace the role of BaO. However, due to its difference in ionic properties, it can fine-tune the chemical potential, interfacial tension, and phase region size between the two phases, making the formed nanoscale phase-separated structure more uniform and stable. At the same time, Sr 2+ The slower diffusion rate helps to fix the phase separation morphology in the early stage of cooling; Li in Li2O + It has the smallest ionic radius (0.76 Å) and the strongest electric field strength among all alkali metals. The introduction of a small amount of Li₂O has a strong fluxing and ion diffusion promoting effect at high temperatures, which is beneficial for melt homogenization; during the cooling stage, due to its high mobility, Li₂O… + It can rapidly diffuse and accumulate at the phase interface formed by the first network. At this time, the larger Sr 2+ Ions also tend to accumulate in the interface region. The two coexist in a specific ratio (R2), forming ion pairs or composite defect centers, which effectively pinning the phase interface and significantly suppressing the tendency of the nanostructure to coarsen or transform into a crystalline state during the cooling process, thereby freezing the metastable nanostructure.

[0027] SrO and Li₂O require a suitable molar ratio R₂ = 0.2-5:1 to achieve optimal synergistic stabilizing effect. Preferably, R₂ = 0.5-2:1, where the concentration matching of the two ions at the interface is optimal, resulting in the strongest pinning effect. If R₂ is too low (Li₂...), the synergistic stabilizing effect will be diminished. + (Relatively excessive), the system has excessively strong high-temperature fluidity, the tendency for phase separation is suppressed, the glaze surface tends to be uniform and glassy, ​​and the gloss is relatively high; at the same time, excessive Li + This can also lead to a mismatch in the coefficients of thermal expansion of the glaze. If R2 is too high (Sr... 2+ (If the amount is relatively excessive), it may form local enrichment zones due to poor matching with matrix ions, which may become heterogeneous nucleation sites for harmful crystallization and destroy the uniformity of the nanophase structure.

[0028] In this embodiment, the total molar amount of K₂O and Na₂O (1-4 mol%) serves as a traditional flux to help lower the melting temperature and improve the glaze slurry's processing performance. Specifically, in the system of this invention, the main control over melting and flowability is achieved by the alkaline earth metal network forming agent (viscosity controlled by R1) and the network modifier (Li). +The strong fluxing agent is responsible for this. Therefore, the K and Na contents can and must be controlled at very low levels. This brings multiple benefits: 1) avoiding uncontrollable increases in gloss due to excessive alkali metals; 2) greatly improving the chemical stability (acid and alkali resistance) of the glaze; 3) improving the hardness and wear resistance of the glaze; (4) reducing the tendency of "alkali corrosion" or "fouling" that may occur in the later stage of the glaze. The ratio of K2O to Na2O affects the high-temperature viscosity curve and the coefficient of thermal expansion. The preferred molar ratio of K2O to Na2O of 1.5-4:1 is beneficial for matching with the body.

[0029] In this embodiment, the total amount of alkaline earth metal network forming agent is 15-32 mol%, and the total amount of network modifier is 0.5-3.5 mol%. This is the material basis for ensuring that the above-mentioned proportion control can be effectively achieved. If the total amount of alkaline earth metal is too low (<15 mol%), there will not be enough network modifying ions to induce significant phase separation; if the total amount is too high (>32 mol%), the glaze will tend to crystallize or become a crystalline glaze, losing its glassy texture. The total amount of network modifier is the minimum guarantee and upper limit constraint for its effectiveness. Too low an amount will be ineffective, while too high an amount may introduce new problems (such as Li). + Excessive amounts can cause drastic changes in the expansion coefficient; preferably, the total molar amount of the network modifier is 1-2.5 mol%.

[0030] In some embodiments, a method for preparing a medium-gloss, super-fouling glaze based on dual-network regulation, as described in this invention, is also provided. Figure 1 As shown, it includes the following steps: S1. Raw material conversion and batching: Based on the chemical composition and the relationship between each oxide, select mineral raw materials and chemical raw materials containing the required elements for weighing. Among them, SrO is introduced by strontium carbonate, and Li2O is introduced by spodumene and / or lithium carbonate. S2. Mixing and ball milling: Mix the prepared raw materials with water and wet ball mill until the glaze slurry has a fineness of 0.05-0.3% residue on a 10,000-mesh sieve and a specific gravity of 1.86-1.92. S3. Glazing and firing: The glaze is applied to the surface of the ceramic body and fired once at a temperature of 1180-1220℃.

[0031] The key to the preparation method of the above-mentioned glaze of the present invention lies in accurately calculating and weighing the corresponding mineral raw materials (such as potassium feldspar, sodium feldspar, talc, kaolin, dolomite, spodumene, etc.) and chemical raw materials (such as barium carbonate, zinc oxide, strontium carbonate, lithium carbonate, etc.) according to the above chemical composition and proportions, and preparing them through a standardized wet ball milling, iron removal and sieving, glazing, and single firing process. Based on the structure-controlled formula design, the glaze effect is insensitive to fluctuations in firing temperature (1180-1220℃) and firing cycle, exhibiting a high degree of process tolerance and making it very suitable for modern large-scale continuous production.

[0032] Furthermore, ceramic tiles prepared using the glaze of the present invention have a glaze surface that combines moderate soft gloss, top-level stain resistance, high transparency, and excellent physicochemical properties.

[0033] The present invention will be further explained and illustrated below through specific embodiments: Example 1 A medium-gloss, ultra-fouling glaze based on dual-network regulation, wherein the chemical composition of the glaze after firing, based on the total molar amount of 100%, comprises: SiO2: 53.1 mol%; Al2O3: 18.3 mol%; CaO: 8.2 mol%; MgO: 6.0 mol%; BaO: 5.1 mol%; ZnO: 4.9 mol%; SrO: 1.0 mol%; Li2O: 1.2 mol%; K2O: 1.5 mol%; Na2O: 0.7 mol%; The molar ratio of CaO and MgO to BaO and ZnO is R1 = 1.42:1; the molar ratio of SrO to Li2O is R2 = 0.83:1; The preparation method includes the following steps: S1. Raw material conversion and batching: Based on the chemical composition and the relationship between the oxides, select and weigh the mineral and chemical raw materials containing the required elements. The raw materials include, by mass, 22.5% potassium feldspar, 6% sodium feldspar, 12% talc, 8% kaolin, 7% zinc oxide, 11% barium carbonate, 20% dolomite, 2% strontium carbonate, 4.5% spodumene, and 7% silica fume. S2. Mixing and ball milling: Mix the prepared raw materials with water and wet ball mill until the glaze slurry has a fineness of 0.2% residue on a 10,000-mesh sieve and a specific gravity of 1.90. S3. Glazing and firing: The glaze is applied to the surface of the ceramic body and fired once at a temperature of 1200℃.

[0034] Example 2 A medium-gloss, ultra-fouling glaze based on dual-network regulation, wherein the chemical composition of the glaze after firing, based on the total molar amount of 100%, comprises: SiO2: 51 mol%; Al2O3: 19.5 mol%; CaO: 7 mol%; MgO: 5.4 mol%; BaO: 8.0 mol%; ZnO: 5 mol%; SrO: 0.8 mol%; Li2O: 1.0 mol%; K2O: 1.7 mol%; Na2O: 0.6 mol%; The molar ratio of CaO and MgO to BaO and ZnO is R1 = 0.95:1; the molar ratio of SrO to Li2O is R2 = 0.8:1; the preparation method includes the following steps: S1. Raw material conversion and batching: Based on the chemical composition and the relationship between the oxides, select and weigh the mineral and chemical raw materials containing the required elements, which include, by mass percentage: 25% potassium feldspar, 5% sodium feldspar, 10% talc, 10% kaolin, 5% zinc oxide, 13% barium carbonate, 22% dolomite, 1.5% strontium carbonate, 3.5% spodumene, and 5% silica fume. S2. Mixing and ball milling: Mix the prepared raw materials with water and wet ball mill until the glaze slurry has a fineness of 0.1% residue on a 10,000-mesh sieve and a specific gravity of 1.86. S3. Glazing and firing: The glaze is applied to the surface of the ceramic body and fired once at a temperature of 1180℃.

[0035] Example 3 A medium-gloss, ultra-fouling glaze based on dual-network regulation, wherein the chemical composition of the glaze after firing, based on the total molar amount of 100%, comprises: SiO2: 55.1 mol%; Al2O3: 16.8 mol%; CaO: 7.5 mol%; MgO: 5.5 mol%; BaO: 4.5 mol%; ZnO: 5.8 mol%; SrO: 1.2 mol%; Li2O: 1.4 mol%; K2O: 1.3 mol%; Na2O: 0.9 mol%; The molar ratio of CaO and MgO to BaO and ZnO is R1 = 1.26:1; the molar ratio of SrO to Li2O is R2 = 0.86:1; the preparation method includes the following steps: S1. Raw material conversion and batching: Based on the chemical composition and the relationship between the oxides, select and weigh the mineral and chemical raw materials containing the required elements, which include, by mass percentage: 20% potassium feldspar, 8% sodium feldspar, 14% talc, 6% kaolin, 9% zinc oxide, 9% barium carbonate, 18% dolomite, 2.5% strontium carbonate, 5.5% spodumene, and 8% silica fume. S2. Mixing and ball milling: Mix the prepared raw materials with water and wet ball mill until the glaze slurry has a fineness of 0.3% residue on a 10,000-mesh sieve and a specific gravity of 1.92. S3. Glazing and firing: The glaze is applied to the surface of the ceramic body and fired once at a temperature of 1220℃.

[0036] Comparative Example 1 (without network modifiers) A glaze, whose chemical composition after firing differs from that of Example 1 in that it does not contain SrO and Li2O, has the following chemical composition on a molar basis: SiO2: 54.2 mol%; Al2O3: 19.4 mol%; CaO: 8.2 mol%; MgO: 6.0 mol%; BaO: 5.1 mol%; ZnO: 4.9 mol%; K2O: 1.5 mol%; Na2O: 0.7 mol%.

[0037] Comparative Example 2 (R1 value too low) A glaze, after firing, differs from Example 1 in that its R1 value is too low. Its chemical composition, on a molar ratio basis, includes: SiO2: 53.1 mol%; Al2O3: 18.3 mol%; CaO: 5.1 mol%; MgO: 4.0 mol%; BaO: 8.1 mol%; ZnO: 7.0 mol%; SrO: 1.0 mol%; Li2O: 1.2 mol%; K2O: 1.5 mol%; Na2O: 0.7 mol%; the ratio of the total molar amount of CaO and MgO to the total molar amount of BaO and ZnO, R1 = 0.6:1.

[0038] Comparative Example 3 (R1 value is too high) A glaze, after firing, differs from Example 1 in that its R1 value is excessively high. Its chemical composition, measured in molar ratio, includes: SiO2: 53.1 mol%; Al2O3: 18.3 mol%; CaO: 9.0 mol%; MgO: 7.0 mol%; BaO: 4.2 mol%; ZnO: 4.0 mol%; SrO: 1.0 mol%; Li2O: 1.2 mol%; K2O: 1.5 mol%; Na2O: 0.7 mol%; the ratio of the total molar amount of CaO and MgO to the total molar amount of BaO and ZnO, R1 = 2:1.

[0039] Comparative Example 4 (R² value too low) A glaze, after firing, differs from Example 1 in that its R2 value is too low. Its chemical composition, on a molar ratio basis, includes: SiO2: 53.1 mol%; Al2O3: 18.3 mol%; CaO: 8.2 mol%; MgO: 6.0 mol%; BaO: 5.1 mol%; ZnO: 4.9 mol%; SrO: 0.2 mol%; Li2O: 2.0 mol%; K2O: 1.5 mol%; Na2O: 0.7 mol%; the ratio of the total molar amounts of CaO and MgO to BaO and ZnO is R1 = 1.42:1; the molar ratio of SrO to Li2O is R2 = 0.1:1.

[0040] Comparative Example 5 (total network modifier = 5 mol% is too high) A glaze, after firing, differs from Example 1 in its chemical composition in that the total amount of network modifier is excessively high. Its chemical composition, on a molar ratio basis, includes: SiO2: 50.3 mol%; Al2O3: 18.3 mol%; CaO: 8.2 mol%; MgO: 6.0 mol%; BaO: 5.1 mol%; ZnO: 4.9 mol%; SrO: 2.3 mol%; Li2O: 2.7 mol%; K2O: 1.5 mol%; Na2O: 0.7 mol%; the ratio of the total molar amount of CaO and MgO to the total molar amount of BaO and ZnO is R1 = 1.42:1; the total molar amount of SrO and Li2O is 5 mol%, and the ratio of the two is R2 = 0.85:1.

[0041] Comparative Example 6 (excessive content of alkali metals K2O and Na2O) A glaze, after firing, differs from Example 1 in its chemical composition in that it contains excessively high levels of alkali metals K₂O and Na₂O. The chemical composition includes: SiO₂: 51.1 mol%; Al₂O₃: 16.5 mol%; CaO: 8.2 mol%; MgO: 6.0 mol%; BaO: 5.1 mol%; ZnO: 4.9 mol%; SrO: 1.0 mol%; Li₂O: 1.2 mol%; K₂O: 3.5 mol%; Na₂O: 2.5 mol%; the ratio of the total molar amount of CaO and MgO to the total molar amount of BaO and ZnO is R₁ = 1.42:1; the molar ratio of SrO to Li₂O is R₂ = 0.83:1; and the total molar amount of K₂O and Na₂O is 6 mol%.

[0042] The glazes prepared in Examples 1-3 and Comparative Examples 1-6 were applied to ceramic tile blanks measuring 300mm × 600mm. After sintering, performance tests were conducted, and the results are shown in Table 1. The specific test methods are as follows: Gloss: Measured at a 60° angle according to GB / T 13891-2008; Stain resistance: Tested using a black oil-based marker according to Appendix M of GB / T 4100-2015, and rated as 1-5, with 5 being the best. Transmittance: A sample with a glaze layer thickness of approximately 0.35 mm was prepared, with a standard blank on the back. The diffuse transmittance at a wavelength of 550 nm was measured using a spectrophotometer with an integrating sphere. Mohs hardness: determined using the Mohs hardness pen scratch method; Chemical resistance: Rating after testing according to GB / T 3810.13-2016.

[0043] Table 1 Performance Test Data

[0044] As can be seen from the data of Examples 1-3 in Table 1, the gloss levels of the three examples are 38 GU, 29 GU, and 42 GU, respectively, all perfectly falling within the target range of 25-45 GU, which is the visually comfortable medium gloss level. This directly proves that by adjusting the R1 value, the glaze surface can be precisely guided to form a specific microscopic scattering structure, thereby achieving a customized gloss level, rather than the uncontrollable or highly fluctuating level of traditional technologies. Examples 1 and 2 achieve the highest level of stain resistance (Level 5), and Example 3 also achieves an excellent Level 4. At the same time, their light transmittance is as high as 68%, 72%, and 65%, respectively, far exceeding the target of 60%. This data combination completely breaks the inherent technical bias of the irreconcilable contradiction between super stain resistance and high transmittance described in the background technology. It proves that through the dual-network control mechanism designed in this invention, a glaze surface that combines high density (the basis for stain resistance) and a nanoscale uniform scattering structure (the basis for soft gloss and high transmittance) can be constructed, rather than the binary opposition structure in traditional technologies where density results in high gloss with no scattering, and scattering results in loose and porous structures. Furthermore, all three embodiments achieved a Mohs hardness of 6 and a chemical resistance of the highest grade A. This indicates that, while achieving breakthroughs in optical performance and surface functionality, the glaze of this invention did not sacrifice the mechanical strength and chemical stability required for ceramic glazes. This is thanks to the robust Si-Al network framework, moderate alkaline earth metal content, and extremely low alkali metal content in the formulation, ensuring the overall strength and inertness of the glaze layer.

[0045] Clearly, the data from Examples 1-3 together constitute a strong chain of evidence proving that the technical solution based on dual-network regulation proposed in this invention is feasible and effective. Specifically: the specific ratio (R1) of the alkaline earth metal network forming agent (first network) is key to forming the ideal nanoscale phase-separated structure. It creates a balance of dynamic competition between ions, induces liquid-liquid phase separation, and forms the source of the soft luster of the glaze (light scattering center) and the structural basis for maintaining high transparency (nanoscale uniformity); the introduction of the network modifier (second network) and its specific ratio (R2) are the core of stabilizing the nanostructure and achieving super anti-fouling. 2+ and Li + The synergistic pinning effect at the phase separation interface freezes the metastable nano-phase structure, preventing it from coarsening or transforming into harmful crystals during cooling. This ensures the extreme density and smoothness of the glaze at the microscopic level, which is fundamental to achieving super anti-fouling properties. The extremely low alkali metal content is the cornerstone of comprehensive performance. It avoids the decrease in chemical stability, hardness reduction, and gloss loss caused by excessive alkali metals, allowing the focus of performance regulation to be concentrated on the dual network, simplifying the complexity of formula design and improving process stability.

[0046] Figures 2-4The images show actual ceramic tiles produced using the glazes described in Examples 1-3 of this invention. Figure 2-4 It can intuitively demonstrate the soft visual feel and medium gloss of the glaze. Unlike the mirror reflection of high-gloss glaze and the complete diffusion of traditional matte glaze, the glaze of Examples 1-3 presents a soft, uniform, and glare-free texture. Figure 2-4 The patterns in the glaze are clear and layered, which verifies that the invention has successfully achieved high transparency and overcomes the problem of blurred patterns caused by crystallization or roughening in traditional medium-gloss glazes. Figure 2-4 The smooth, uniform, and defect-free glaze appearance is an external manifestation of the ideal nano-phase structure formed internally, rather than large-sized crystals or a rough surface. This indirectly proves the effectiveness of the dual-network regulation mechanism (alkaline earth metal network forming agent induces phase separation, and network modifier stabilizes the structure).

[0047] A point-by-point comparison of each comparative example with the high-performance Example 1 clearly reveals that once any key technical feature defined by this invention is deviated from, the performance of the resulting product will be significantly degraded, or even completely unable to achieve the purpose of the invention. The specific analysis is as follows: In Comparative Example 1, the gloss level soared to 52 GU (exceeding the target range), the stain resistance dropped to level 3, the light transmittance dropped to 58% (close to the target bottom line), and both the hardness and chemical resistance decreased.

[0048] This directly proves that the introduction of network modifiers (SrO / Li2O) is one of the core inventive aspects of this invention. Without them, the alkaline earth metal network forming agent (first network) alone cannot effectively stabilize the nanoscale phase-separated structure. The glaze tends to form a more uniform glassy state (leading to excessive gloss), or the phase-separated structure becomes unstable and coarsens (leading to decreased stain resistance and light transmittance). 2+ and Li + The synergistic pinning effect is crucial for freezing the ideal structure; its absence leads to the collapse of the entire performance system. This refutes the assumption that a similar effect can be achieved simply by adjusting the proportion of alkaline earth metals, highlighting the independent and critical stabilizing function of network modifiers.

[0049] Comparative Example 2 exhibited extremely high gloss (56 GU), extremely poor stain resistance (Level 2), and the lowest light transmittance (52%), demonstrating that there exists a precise equilibrium window for the internal ratio (R1) of the alkaline earth metal network forming agent. When R1 is too low, it indicates excessive network breaking in the BaO / ZnO, resulting in excessively low high-temperature viscosity of the glaze and over-vitrification. This inhibits the formation of beneficial phase separation structures, leading to a mirror-like glaze (high gloss), and the structure may develop microscopic defects (pinholes) due to overfiring, severely impairing density (poor stain resistance) and uniformity (poor light transmittance). The lower limit of 0.8 for R1 is not arbitrarily set, but rather a critical threshold for maintaining moderate network aggregation and inducing controllable phase separation.

[0050] The gloss level in Comparative Example 3 was too low (22 GU, entering the matte zone), its stain resistance was average (level 3), and its light transmittance deteriorated sharply (48%). This, in turn, demonstrates the importance of the R1 value balance window. When R1 is too high, the network aggregation of CaO / MgO is too strong, and the high-temperature viscosity is too high, which easily induces the precipitation of micron-sized crystals (such as diopside and wollastonite), rather than the nano-phase separation desired by this invention. These crystals become strong light scattering centers, reducing the gloss level to the matte range and causing a severe opacification effect, completely sacrificing light transmittance. The boundaries between crystals can also become channels for stain penetration, reducing stain resistance. Therefore, an upper limit of 1.5 is a key boundary for preventing harmful crystallization and maintaining the glassy nano-phase separation characteristics of the glaze.

[0051] Comparative Example 4 showed a higher gloss (50 GU), decreased stain resistance (level 3), and overall performance degradation. This reveals the crucial importance of the synergistic effect of the internal proportion (R2) of the network modifier. + Small ionic radii and high mobility mean that excessive Sr can lead to excessive melt fluidity at high temperatures, which in turn inhibits the formation of phase-separated structures, resulting in a glaze that tends towards homogeneous glass (high gloss). Meanwhile, a lack of sufficient Sr... 2+ Come with Li + The formation of effective ion pairs at the interface pinning centers makes any fine structures formed unstable upon cooling. This indicates that SrO and Li2O do not work simply by superposition, but require a specific ratio (R2 in the range of 0.2-5, preferably 0.5-2) to produce a synergistic stabilizing effect greater than the sum of its parts.

[0052] Comparative Example 5 showed a high gloss (48 GU), microcracks, decreased hardness, and a chemical resistance rating reduced to Grade B. This demonstrates that the content of the network modifier needs to be strictly controlled within a certain range (0.5-3.5 mol%). Excessive modifiers, especially Li₂O, significantly alter the coefficient of thermal expansion of the glaze, leading to stress between the glaze layer and the body or within the glaze layer, thereby inducing microcracks and directly compromising the integrity and durability of the glaze surface. Simultaneously, excessive ions may also disrupt the main network structure, causing performance to deviate from expectations. This indicates that the success of this invention lies not in simply adding certain special components, but in the systematic balance of the content and proportion of all components.

[0053] The performance of Comparative Example 6 completely collapsed: its gloss was out of control (58 GU), its stain resistance was extremely poor (level 2), its hardness dropped significantly to level 4, and its chemical resistance dropped to the worst level C. This demonstrates, from the opposite extreme, that controlling the alkali metal content at an extremely low level (1-4 mol%) is a prerequisite and a huge advantage for the success of this solution. Traditional glazes often rely on alkali metals as the main flux, but this invention achieves melting and structural control through a dual-network approach, thus daring to and being able to significantly reduce the alkali metal content. Comparative Example 6 shows that once the traditional approach of high alkali metals is adopted, it leads to a sharp decrease in the chemical stability of the glaze (easy to be corroded by acids and alkalis), a decrease in hardness (not wear-resistant), and easy alkali corrosion and staining. Moreover, the strong fluxing effect of alkali metals can cause excessive flow of the glaze, making the gloss uncontrollable. This highlights the advanced and non-obvious nature of the design concept of reducing dependence on alkali metals in this invention.

[0054] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A medium-gloss, ultra-foul-resistant glaze based on dual-network regulation, characterized in that, Based on the total molar amount of the chemical composition of the glaze after firing, which is 100%, the chemical composition includes: SiO2: 45-60 mol% Al2O3: 10-25 mol% Alkaline earth metal network forming agent, composed of CaO, MgO, BaO and ZnO, and satisfying the ratio of the total molar amount of CaO and MgO to the total molar amount of BaO and ZnO is 0.8-1.5:1; The network modifier is composed of SrO and Li2O, and the molar ratio of SrO to Li2O is 0.2-5:

1. The total molar content of K2O and Na2O is 1-4 mol% The total molar amount of the alkaline earth metal network forming agent is 15-32 mol, and the total molar amount of the network modifier is 0.5-3.5 mol.

2. The medium-gloss, ultra-fouling glaze based on dual-network regulation according to claim 1, characterized in that, The ratio of the total molar amount of CaO and MgO to the total molar amount of BaO and ZnO is 1-1.3:

1.

3. The medium-gloss, ultra-fouling glaze based on dual-network regulation according to claim 1, characterized in that, The molar ratio of SrO to Li2O is 0.5-2:

1.

4. The medium-gloss, ultra-fouling glaze based on dual-network regulation according to any one of claims 1-3, characterized in that, The total molar amount of the network modifier is 1-2.5 mol.

5. The medium-gloss, ultra-fouling glaze based on dual-network regulation according to claim 1, characterized in that, The molar ratio of K2O to Na2O is 1.5-4:

1.

6. The medium-gloss, ultra-fouling glaze based on dual-network regulation according to claim 1, characterized in that, The glaze surface made from the glaze with the aforementioned chemical composition has a gloss level of 25-45 GU at 60°.

7. A method for preparing a medium-gloss, super-fouling glaze based on dual-network regulation as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Raw material conversion and batching: Based on the chemical composition and the relationship between each oxide, select mineral raw materials and chemical raw materials containing the required elements for weighing. Among them, SrO is introduced by strontium carbonate, and Li2O is introduced by spodumene and / or lithium carbonate. S2. Mixing and ball milling: Mix the prepared raw materials with water and wet ball mill until the glaze slurry has a fineness of 0.05-0.3% residue on a 10,000-mesh sieve and a specific gravity of 1.86-1.

92. S3. Glazing and firing: The glaze is applied to the surface of the ceramic body and fired once at a temperature of 1180-1220℃.

8. A ceramic tile, characterized in that, Its surface is coated with a medium-gloss, ultra-fouling glaze based on dual-network regulation as described in any one of claims 1-6.

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