Metallic luster ceramic tile and preparation method thereof

Abstract

This invention discloses a metallic ceramic tile and its preparation method, belonging to the field of decorative ceramic technology. The metallic ceramic tile comprises a body layer and a metallic glaze layer adhered to the surface of the body layer. The raw materials for preparing the metallic glaze layer contain phosphorus minerals as a melting aid. By adding specific phosphorus minerals to the metallic glaze formulation, this invention effectively improves the venting performance of the glaze during firing, significantly reduces pinhole defects on the surface of the metallic glaze layer, and enhances the surface texture and decorative effect of the tile. Furthermore, the tile may also include an embossed layer, a base glaze layer, and a transparent wear-resistant protective layer, forming a multi-layered three-dimensional decorative structure with strong metallic luster, good three-dimensional effect, and excellent wear resistance, making it suitable for high-value-added wall decoration materials.

Description

Technical Field

[0001] This invention relates to the field of decorative ceramics, and in particular to a metallic-luster ceramic tile and its preparation method. Background Technology

[0002] With the upgrading of the interior decoration industry, consumers' demand for decorative wall and background wall tiles is constantly increasing. Traditional flat printed tiles have problems such as monotonous texture, bland texture and lack of artistic expression. Therefore, in the currently available technology, metallic glaze is generally added to increase the metallic luster effect of the tiles, thereby improving the visual texture of the tiles.

[0003] The core components of metallic glazes typically include metal oxides or metal oxide pigments. While these give the tiles a nice glossy texture, they can also affect the air venting during the firing process, resulting in a large number of pinholes on the glaze and impacting the tile's appearance and user experience. Summary of the Invention

[0004] The main objective of this invention is to propose a metallic luster ceramic tile and its preparation method, which aims to improve the problem of pinholes easily appearing in the metallic luster glaze layer on the surface of metallic luster ceramic tiles in the prior art.

[0005] A metallic ceramic tile includes: a body layer and a metallic glaze layer attached to the surface of the body layer, wherein the raw materials for preparing the metallic glaze layer contain phosphorus minerals as a melting aid.

[0006] Metallic glazes contain a large amount of metal oxides that release gases during firing. If the melt is not properly vented, the gases will be trapped, forming pinholes. Phosphorus oxides from bovine bone ash, apatite, and silicon phosphate can be selected from phosphorus-containing minerals. At high temperatures, the surface tension and viscosity of the glaze melt can be adjusted to promote the coalescence, rising, and escape of bubbles, thereby completing the venting process before the glaze surface is completely melted and sealed.

[0007] Preferably, the phosphorus-containing mineral is silicon phosphate, and by mass percentage, the silicon phosphate accounts for 4wt%-7wt% of the raw material used in the metallic luster glaze.

[0008] Phosphorus-containing minerals are preferably silicon phosphate, and its dosage has a significant impact on the surface effect of metallic glaze. If the dosage of silicon phosphate is too low, there will be insufficient melting aid, and the viscosity and surface tension of the glaze melt will not be sufficiently adjusted to the window range that facilitates bubble expulsion, resulting in incomplete venting and a small number of pinholes remaining. When the dosage of silicon phosphate is further increased and exceeds the optimal process window, the excessive P2O5 will change the structural state of the melt, which may lead to the formation of more phosphorus-oxygen network structures in the system. This will cause the high-temperature fluidity of the glaze melt to increase instead of decrease, and the viscosity to rise again, thereby hindering the complete expulsion of bubbles and affecting the venting effect.

[0009] Preferably, the ratio of P2O5 to SiO2 in the silicon phosphate is 1.5 to 3:1.

[0010] This invention further limits the mass ratio of P2O5 to SiO2 in silicon phosphate to 1.5~3:1. Within this range, P2O5 provides sufficient flux to reduce the viscosity of the glaze melt and promote bubble removal, while the phosphorus-oxygen network structure can maintain the high-temperature skeleton stability of the glaze layer and prevent excessive melt flow that could lead to glaze runoff and blurred relief contours.

[0011] Preferably, the raw materials for preparing the metallic luster glaze layer, by weight, include: 40-50 parts potassium feldspar, 20-30 parts quartz, 5-10 parts alumina, 5-10 parts calcite, 3-8 parts silicon phosphate, 12-18 parts calcined kaolin, 8-15 parts metal oxide pigment, and 0.3-0.6 parts dispersant. The metal oxide pigment includes one or more of iron oxide, manganese oxide, copper oxide, and cobalt oxide. The dispersant includes one or more of sodium tripolyphosphate, water glass, and ammonium polyacrylate.

[0012] This invention constructs a glass-forming system with potassium feldspar, quartz, alumina, and calcined kaolin as its framework, and combines this with the synergistic effect of silicon phosphate melt regulation. This ensures that the metal oxide pigments are fully colored while effectively promoting the smooth escape of gases during the firing process. This results in a pinhole-free metallic glaze that effectively prevents dirt and grime from accumulating on the surface of the ceramic tile, thus improving its stain resistance.

[0013] Preferably, by weight, an embossed layer is further attached between the body layer and the metallic glaze layer. The raw materials for preparing the embossed layer include: 40-60 parts of albite, 10-15 parts of quartz powder, 3-8 parts of mullite fiber, 8-12 parts of kaolin, 3-6 parts of sodium bentonite, 2-5 parts of barium carbonate, 4-8 parts of zinc oxide, 8-15 parts of zirconium silicate, 0.1-0.3 parts of sodium tripolyphosphate, and 0.05-0.2 parts of carboxymethyl cellulose.

[0014] Preparing an embossed layer on the ceramic body enhances the three-dimensional effect of the tile and increases its decorative appeal. Sodium-based bentonite significantly increases the viscosity of the glaze, while mullite fibers, when fired at 1200-1300℃, further improve the glaze viscosity. This prevents issues like glaze flow, collapse, and blurred edges at high temperatures, ensuring a complete three-dimensional outline and a clear, three-dimensional texture. Furthermore, the embossed layer has a softening temperature 30-50℃ higher than the metallic glaze layer. During firing, the metallic glaze layer melts, degassing, and develops color preferentially, while the embossed layer maintains higher viscosity and skeletal strength. This prevents glaze flow, collapse, or blurred edges at high temperatures, ensuring the metallic glaze layer is unaffected by interfacial diffusion and that the metallic luster effect is stably maintained.

[0015] Preferably, a base glaze layer is also attached to the body layer, and the relief layer covers the surface of the base glaze layer. The raw materials for preparing the base glaze layer, by mass parts, include: 70-80 parts of transparent frit, 13-18 parts of pearlescent powder, 5-10 parts of matting powder, and 0.4-0.8 parts of carboxymethyl cellulose. The chemical composition of the transparent frit includes: 40-55% SiO2, 5-15% Al2O3, 5-15% B2O3, 2-5% Na2O, 1-8% K2O, 3-8% CaO, 1-4% MgO, 3-7% ZnO, and 7-12% ZrO. The pearlescent powder includes one or more of synthetic mica, flaky silica, flaky alumina, and glass flakes. The matting powder includes one or more of talc, diatomaceous earth, and zircon.

[0016] The pearlescent and matte powders in the base glaze layer will produce a light contrast after firing, forming a fine frosted pearlescent effect, giving the base glaze a matte texture and providing a certain degree of wear resistance. This contrasts sharply with the high gloss of the metallic glaze layer, avoiding the visual fatigue of a fully high-gloss surface, while also making the three-dimensionality of the metallic pattern more prominent.

[0017] Preferably, the raw materials for preparing the green body layer, by mass parts, include: 30-40 parts of washed kaolin, 15-25 parts of potassium feldspar, 10-20 parts of sodium feldspar, 15-25 parts of quartz sand, 2-5 parts of talc, and 3-6 parts of calcined alumina.

[0018] The body layer provides a pure white substrate for the relief layer and a pure white optical base for the base glaze layer, enhancing the pearlescent matte effect and highlighting the three-dimensionality of the relief layer and the color saturation of the metallic luster.

[0019] Preferably, a transparent wear-resistant protective layer is also attached to the metallic glaze layer. The raw materials for preparing the transparent wear-resistant protective layer include: 80-90 parts of frit, 5-20 parts of wear-resistant material, and 0.3-0.7 parts of rheology modifier. The chemical composition of the frit includes: 50-65% SiO2, 15-25% Al2O3, 3-10% B2O3, 4-8% CaO, 2-4% MgO, 3-7% ZnO, and 1-3% Li2O. The wear-resistant material includes one or more of cubic boron nitride, white corundum, fused mullite, and micron-sized zirconium oxide. The rheology modifier includes one or more of sodium bentonite, propylene glycol, lithium magnesium silicate, and carboxymethyl cellulose.

[0020] This invention sets a transparent wear-resistant protective layer on the metallic glaze. With its transparency, it effectively improves the wear resistance of the tile surface without affecting the metallic luster and three-dimensional relief effect.

[0021] Preferably, the preparation of a metallic-luster ceramic tile includes the following steps: S1. Prepare the green body layer by applying a base glaze to its surface to prepare the base glaze layer. The base glaze layer has a uniform thickness and forms a smooth, pearlescent matte base after firing.

[0022] S2. Prepare the relief layer by printing the relief glaze onto the base glaze layer. Print three-dimensional petals and branches according to the set content to prepare a relief layer with a three-dimensional floral pattern.

[0023] S3. Apply a metallic glaze to the pattern branches and outline edges of the relief layer to prepare the metallic glaze layer, and then coat the metallic glaze layer and the relief layer with a transparent protective glaze to prepare the transparent wear-resistant protective layer. Applying the metallic glaze to some positions on the pattern branches and outline edges of the relief layer that are more prominent than the entire three-dimensional pattern makes the visual effect more refined and high-end.

[0024] S4. The glazed blank prepared according to the above steps is sent into the kiln for firing. The firing temperature is controlled at 1180~1280℃, and the firing cycle is 55-80 minutes. Firing within this temperature range can ensure the three-dimensional effect of the relief layer and prevent glaze from flowing or collapsing. On the other hand, it can also allow the metallic glaze layer to fully release air and develop color. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Appendix Figure 1 The ceramic tile is fired according to the implementation scheme of Example 5.

[0027] Appendix Figure 2 The ceramic tile was fired according to the embodiment of Comparative Example 2. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. At the same time, the raw materials mentioned below, unless otherwise specified, are all commercially available products; the process steps or preparation methods not mentioned in detail are all process steps or preparation methods known to those skilled in the art.

[0029] Test method: Number of pinholes on the tile surface: A 20cm x 20cm area is selected as the observation field on the three-dimensional relief of the tile, and the number of pinholes within the field of view is observed visually from a distance of 0.5 meters from the tile surface. The test standards are as follows: ≥15 pinholes are considered excessive; <15 pinholes but ≥8 pinholes are considered relatively numerous; <8 pinholes but ≥1 pinholes are considered relatively few; 0 pinholes are considered no pinholes.

[0030] Gloss of metallic glaze: The gloss was measured using a 60° geometric angle gloss meter according to the standard method of GB / T 9754 (or ASTM D523), and the gloss value was recorded.

[0031] Wear resistance rating: Tested according to the national standard GB / T3810.7-2016 method. The wear condition of the brick surface after grinding at a specific number of grinding revolutions is observed and divided into 0-5 levels. Among them, visible wear after 100 revolutions is level 0, visible wear after 150 revolutions is level 1, visible wear after 600 revolutions is level 2, visible wear after 750 / 1500 revolutions is level 3, visible wear after 2100 / 6000 / 12000 revolutions is level 4, and visible wear after more than 12000 revolutions is level 5.

[0032] Stain resistance rating: Tested according to the national standard GB / T3810.14-2016 method. The stain resistance performance of the brick surface after surface treatment is tested. The test principle is to bring the staining agent (chrome green, iodine and olive oil, etc.) into contact with the front of the brick and let it act for a certain period of time. Then, the brick surface is cleaned according to the prescribed cleaning method, and the changes on the brick surface are observed to determine the stain resistance of the brick. The rating is divided into 1-5 levels, with level 5 having the best stain resistance performance.

[0033] Overall texture of the tile surface: This is assessed by direct visual observation, primarily evaluating the overall texture resulting from the three-dimensional effect, surface gloss, and texture of the tiles prepared using this method.

[0034] Example 1 S1. Preparation of the green body: According to the mass fraction, take the following raw materials for the green body layer: 15 parts kaolin, 16 parts potassium sodium stone powder, 18 parts potassium sand, 13 parts sodium stone powder, 18 parts black mud, 5 parts black talc, 8 parts polishing mud, and 7 parts mud paste. Ball mill them to a fineness of 0.5% residue on a 325-mesh sieve. After spray drying, they are made into fine powder and then pressed into the green body layer.

[0035] S2. Preparation of metallic luster glaze: By mass, take the following raw materials for metallic luster glaze: 26 parts potassium feldspar, 16 parts quartz, 18 parts wollastonite, 10 parts barium carbonate, 6 parts talc, 6 parts calcined kaolin, 14 parts zinc oxide, 5 parts iron oxide, and 3 parts silicon phosphate. Prepare the slurry and then print it onto the blank layer.

[0036] S3. Ceramic tile firing: The prepared ceramic tile blanks are sent into a roller kiln for firing at a temperature of 1225℃ for 65 minutes to obtain the finished metallic ceramic tile.

[0037] Example 2 S1. Preparation of the green body layer: According to the mass fraction, take the following raw materials for the green body layer: 35 parts of washed kaolin, 20 parts of potassium feldspar, 15 parts of sodium feldspar, 20 parts of quartz sand, 5 parts of talc, and 5 parts of calcined alumina. Ball mill them to a fineness of 0.5% residue on a 325-mesh sieve. After spray drying, they are made into fine powder and then pressed into a green body layer.

[0038] S2. Preparation of metallic luster glaze: By mass, take the following metallic luster glaze: 43 parts potassium feldspar, 20 parts quartz, 5 parts alumina, 5 parts calcite, 5 parts silicon phosphate, 12 parts calcined kaolin, 10 parts iron oxide metal oxide pigment, and 0.3 parts sodium tripolyphosphate dispersant. Prepare this slurry and print it onto the body layer.

[0039] S3. Ceramic tile firing: The prepared ceramic tile blanks are sent into a roller kiln for firing at a temperature of 1225℃ for 65 minutes to obtain the finished metallic ceramic tile.

[0040] Example 3 S1. Preparation of the green body layer: According to the mass fraction, take the following raw materials for the green body layer: 35 parts of washed kaolin, 20 parts of potassium feldspar, 15 parts of sodium feldspar, 20 parts of quartz sand, 5 parts of talc, and 5 parts of calcined alumina. Ball mill them to a fineness of 0.5% residue on a 325-mesh sieve. After spray drying, they are made into fine powder and then pressed into a green body layer.

[0041] S2. Preparation of the relief layer: By weight, take the following relief glaze: 50 parts albite, 11 parts quartz powder, 5 parts mullite fiber, 10 parts kaolin, 5 parts sodium bentonite, 5 parts barium carbonate, 6 parts zinc oxide, 8 parts zirconium silicate, 0.15 parts sodium tripolyphosphate, and 0.2 parts carboxymethyl cellulose. After preparing the slurry, use a multi-channel digital inkjet printer to 3D print the preset floral pattern on the base glaze layer. The printing resolution is 600 dpi. During the printing process, layered printing is performed: first print the main petals, then print the leaf veins and branch details.

[0042] S3. Preparation of the metallic glaze layer: By weight, the metallic glaze comprises: 45 parts potassium feldspar, 22 parts quartz, 7 parts alumina, 6 parts calcite, 6 parts silicon phosphate, 12 parts calcined kaolin, 10 parts copper oxide metal oxide pigment, and 0.3 parts sodium tripolyphosphate dispersant. This mixture is then made into a slurry and printed onto the outlines of branches, veins, and petals in the relief layer, giving the floral pattern on the fired ceramic tile surface a metallic luster and highlighting the three-dimensional effect of the flowers.

[0043] S4. Ceramic tile firing: The prepared ceramic tile blanks are sent into a roller kiln for firing at a temperature of 1225℃ for 65 minutes to obtain the finished metallic ceramic tile.

[0044] Example 4 S1. Preparation of the green body layer: By mass fraction, take the following raw materials for the green body layer: 35 parts washed kaolin, 20 parts potassium feldspar, 15 parts sodium feldspar, 20 parts quartz sand, 5 parts talc, and 5 parts calcined alumina. Ball mill them to a fineness of 0.5% residue on a 300-mesh sieve. After spray drying, they are made into fine powder and then pressed into a green body layer. The whiteness of the prepared green body layer is 85%.

[0045] S2. Preparation of the base glaze layer: By weight, take the following raw materials for the base glaze layer: 77 parts transparent frit, 15 parts synthetic mica pearlescent powder, 8 parts diatomaceous earth matting powder, and 0.5 parts carboxymethyl cellulose. Prepare a slurry and spray it onto the surface of the body layer. By weight percentage, the transparent frit comprises: 49% SiO2, 12% Al2O3, 39% B2O, 3% Na2O, 3% K2O, 5% CaO, 2% MgO, 7% ZnO, and 10% ZrO2. S3. Preparation of the relief layer: By weight, take the following relief glaze: 50 parts albite, 12 parts quartz powder, 6 parts mullite fiber, 10 parts kaolin, 5 parts sodium bentonite, 5 parts barium carbonate, 6 parts zinc oxide, 8 parts zirconium silicate, 0.15 parts sodium tripolyphosphate, and 0.2 parts carboxymethyl cellulose. After preparing the slurry, use a multi-channel digital inkjet printer to 3D print the preset floral pattern on the base glaze layer. The printing resolution is 600 dpi. During the printing process, layered printing is performed: first print the main petals, then print the leaf veins and branch details.

[0046] S4. Preparation of the metallic glaze layer: By weight, take the following metallic glaze components: 48 parts potassium feldspar, 26 parts quartz, 8 parts alumina, 8 parts calcite, 6 parts silicon phosphate, 15 parts calcined kaolin, 12 parts iron oxide metal oxide pigment, and 0.5 parts sodium tripolyphosphate dispersant. After preparing this slurry, print it onto the outlines of branches, veins, and petals in the relief layer, giving the floral pattern on the fired tile surface a metallic luster and highlighting the three-dimensional effect of the flowers.

[0047] S5. Ceramic tile firing: The prepared ceramic tile blanks are sent into a roller kiln for firing at a temperature of 1225℃ for 65 minutes to obtain the finished metallic ceramic tile.

[0048] Example 5 The only difference between this embodiment and Embodiment 4 is that a wear-resistant protective layer is added to the surface of the metal glaze layer and the embossed layer. Its preparation method and composition are as follows: Preparation of the wear-resistant protective layer: By mass percentage, take 90 parts of transparent protective glaze, 10 parts of frit, 10 parts of white corundum wear-resistant material, and 0.5 parts of rheology modifier. The frit's chemical composition, by mass percentage, includes 59% SiO2, 18% Al2O3, 6% B2O3, 6% CaO, 3% MgO, 5% ZnO, and 3% Li2O. After preparing it into a slurry, apply a layer to the surface of the relief layer and the metallic glaze layer to form the wear-resistant protective layer.

[0049] The experimental results data from Examples 1 to 5 are shown in Table 1: Table 1: In Example 1, a metallic glaze is applied to the surface of the ceramic body, and silicon phosphate is added to the metallic glaze as a melting aid. This can effectively reduce the number of pinholes on the surface of the ceramic tile, keep the surface of the ceramic tile flat and smooth, make it difficult for dirt to accumulate, improve the stain resistance of the ceramic tile, and achieve a stain resistance level of 3.

[0050] In Example 2, the metallic glaze provided by this technical solution can effectively enhance the metallic luster effect of the tile surface and prevent pinholes from forming on the surface, thereby raising the stain resistance level to level 4. This is because the calcite in the metallic glaze of this technical solution decomposes at a lower temperature during the firing process, and the gas evaporates earlier, which is conducive to the effective discharge of gas, thus solving the pinhole problem on the surface of the metallic glaze layer. It also improves the density of the tile surface, making its wear resistance better than that of conventional metallic glazes.

[0051] In Example 3, a pre-designed floral pattern is first inkjet-printed onto the ceramic body to create an embossed layer, effectively enhancing the three-dimensional decorative effect of the tile. Then, a metallic glaze is applied to the flower branches and edges on the embossed layer, allowing the petals and branches to emit a metallic sheen that contrasts with the floral pattern. This prevents the metallic luster from being too glaring, making the texture clearer and enhancing the sophistication and refinement of the embossed pattern. The mullite fibers and sodium bentonite in the embossed glaze increase its viscosity. Even when fired at 1225℃, the mullite fibers maintain a high viscosity, ensuring the glaze viscosity remains between 8000 and 12000 mPa·s, preventing glaze flow and edge collapse at the pattern edges. This results in a clear, three-dimensional floral texture, enhancing the overall three-dimensional effect of the tile.

[0052] In Example 4, after applying a base glaze layer to the surface of the body, an embossed layer is then applied. The base glaze layer, through the light contrast produced by the firing of pearlescent powder and matte powder, forms a delicate matte pearlescent effect, creating a texture contrast with the embossed floral pattern and enhancing its artistic appeal.

[0053] In Example 5, a layer of transparent protective glaze was finally applied to the surface of the embossed floral pattern and metallic glaze as a wear-resistant protective layer, improving the wear resistance to level 4 while maintaining a good stain resistance of level 5. After firing, the transparent frit forms a colorless, non-crystallized, homogeneous glassy state, ensuring no loss of gloss. White corundum and alumina enhance wear resistance, and the addition of rheology modifiers creates a dense, defect-free glassy surface free of pinholes and cracks, making it less prone to dirt accumulation, thus improving the stain resistance of the tile surface from level 4 to level 5. Figure 1 As shown, the entire tile has a distinct three-dimensional effect, a complete surface, and no pinholes affecting the metallic luster, resulting in a strong metallic sheen and maximizing both practicality and decorative appeal.

[0054] Example 6 The only difference between this embodiment and embodiment 4 is that different types of phosphorus-containing minerals are added to the metal glaze. In embodiment 6-1, phosphorus pentoxide is used to replace silicon phosphate; in embodiment 6-2, bovine bone ash is used to replace silicon phosphate; and in embodiment 6-3, apatite is used to replace silicon phosphate. The relevant experimental data are shown in Table 2.

[0055] Comparative Example 1 The only difference between this comparative example and Example 4 is that nepheline is used instead of silicon phosphate. The relevant experimental data are shown in Table 2.

[0056] Comparative Example 2 The only difference between this comparative example and Example 4 is that silicon phosphate was removed from the metallic glaze. The relevant experimental data are shown in Table 2.

[0057] Table 2 In Example 6-1, replacing silicon phosphate with P2O5 alone can significantly reduce melt viscosity and improve fluidity, which is beneficial for bubble floating. However, due to the lack of structural support from the silicon-oxygen skeleton in silicon phosphate, the viscosity of the system decreases too much. This causes the glaze to soften and level prematurely before the bubbles are completely eliminated, and the remaining small bubbles are eventually locked in the glaze layer, making it impossible to achieve a perfect glaze without pinholes.

[0058] In Example 6-2, although P2O5 is also present in ox bone ash, which can improve the flow of the metal glaze by reducing its viscosity, allowing the gas in the metal glaze to flow out quickly, ox bone ash itself will release more impurity gases during the firing process, resulting in an increased burden of volatile gases, which can easily increase the number of pinholes and affect the gloss and texture clarity of the tile surface.

[0059] In Examples 6-3, apatite does not introduce additional impurity gases. The presence of P2O5 effectively reduces the number of pinholes. However, the volatilization of fluoride ions in apatite causes some pits to form on the glaze surface, affecting the smoothness of the metallic glaze layer and reducing the gloss and texture of the relief pattern.

[0060] In Comparative Example 1, although nepheline can also reduce the viscosity of metallic glaze, improve fluidity, and increase gas volatilization, it will seriously affect the color development of metallic glaze, reduce the gloss of relief patterns to 40 degrees, seriously affect the decorative and aesthetic appeal of the tiles, and significantly reduce the metallic luster on the tile surface.

[0061] In Comparative Example 2, many metal oxide colorants were added to the metallic glaze. These colorants undergo decomposition or redox reactions during high-temperature firing, releasing gases. However, due to the excessively high viscosity during firing, the bubbles rise slowly, causing residual bubbles to be "locked" inside or on the surface of the glaze. After cooling, these bubbles form pinhole defects, which reduce the surface smoothness and negatively impact the gloss of the relief pattern. Figure 2 As shown, since no silicon phosphate was added in this comparative example, the number of pinholes on the surface of the embossed pattern increased significantly. The pinholes could not display a metallic luster effect, which reduced the metallic luster and affected the visual appeal.

[0062] Example 7 The only difference between this embodiment and Embodiment 4 is that different amounts of silicon phosphate are used in the metallic glaze to investigate the effect of the melting aid on the number of pinholes on the surface of the metallic glaze. The dosage and the resulting effect data are shown in Table 3.

[0063] Table 3 Data from Example 7 shows that the amount of silicon phosphate significantly affects the pinhole defects, glaze melt viscosity, and gloss of the metallic glaze. When the amount of silicon phosphate is 4wt%-7wt%, the glaze melt viscosity is within a suitable range, allowing bubbles to be fully expelled, resulting in a pinhole-free glaze surface. Simultaneously, the gloss reaches 63-68 degrees, and the overall texture exhibits a distinct three-dimensional effect, strong metallic luster, and refined texture. When the amount is below 4wt% or above 7wt%, pinhole defects tend to reappear, but can still be controlled to a low level.

[0064] The effect of silicon phosphate dosage on glaze viscosity exhibits a U-shaped curve. Within the dosage range of 0-7 wt%, P2O5 primarily acts as a network modifier, continuously reducing melt viscosity and improving fluidity. This trend facilitates bubble removal. However, when the dosage reaches approximately 7 wt%, the excessively low viscosity leads to a thinner glaze layer, unstable boundaries, and even glaze flow, thus impairing the three-dimensional effect of the relief. Furthermore, when the silicon phosphate dosage increases further to over 8 wt%, excess P2O5 begins to alter the melt structure, potentially promoting the formation of more phosphorus-oxygen networks. This causes the viscosity to rebound from its lowest point, resulting in decreased fluidity, hindering bubble removal, and causing pinholes to reappear.

[0065] Example 8 The only difference between this embodiment and Embodiment 4 is that the mass ratio of phosphorus pentoxide to silicon dioxide in silicon phosphate is different, by mass percentage, to investigate the effect of this ratio on the metallic luster glaze. Relevant experimental data are shown in Table 4.

[0066] Table 4 When the P2O5 / SiO2 ratio is too low (e.g., 1.1-1.4 / 1), the P2O5 in silicon phosphate, which acts as a flux and degassing agent, is relatively insufficient, resulting in limited improvement in the metallic luster of the tile. Furthermore, it leads to higher viscosity of the metallic glaze, poor flowability, and slow rise of bubbles in the excessively viscous melt. These bubbles fail to escape completely before the glaze seals, remaining in the glaze layer and forming pinholes, ultimately reducing gloss and texture clarity. When the P2O5 / SiO2 ratio is too high (e.g., 3.1-4.0 / 1), although the strong fluxing effect of P2O5 provides some degassing ability and improves gloss (to 68 degrees), the increased phosphorus-oxygen network structure in the melt increases viscosity and reduces fluidity, making it difficult for bubbles to escape and reducing the texture effect. However, when the P2O5 / SiO2 ratio is within the range of 1.5-3.0 / 1, the balanced ratio and moderate viscosity prevent pinholes from forming on the tile surface, resulting in a refined texture.

[0067] Example 9 The only difference between this embodiment and Embodiment 5 is the firing temperature of the brick blank. The effect of firing temperature on ceramic tiles is shown in Table 5: Table 5 Data from Example 9 shows that firing temperature has a decisive influence on the various properties of the multi-layer composite ceramic tile of this invention. When the temperature is controlled within the range of 1180-1280℃, the key components in each functional layer reach their softening and melting temperatures. The base glaze layer is fully sintered and dense (forming a pearlescent matte base), the metallic glaze layer is completely degassed (no pinholes) and has a full color (gloss level 65-68), the relief layer is moderately melted but the fiber skeleton is effectively preserved (three-dimensional effect ≥2mm), and the protective layer is fully densified (wear resistance level 4, stain resistance level 5). The four layers simultaneously complete chemical eutectic melting and interfacial bonding, achieving optimal comprehensive performance. Below 1180℃, the sintering of each layer is not dense, and the performance does not meet the standards; above 1280℃, the molten material of the relief layer is excessively thinned, making it prone to collapse and glaze flow, resulting in loss of the protective layer function, deterioration of overall performance, and excessively high temperatures can also damage the phosphorus-oxygen network, destroy the supporting skeleton of the metallic glaze layer, and affect the texture effect. Therefore, 1180-1280℃ is the preferred firing temperature range of this invention, which ensures the full realization of the functions of each layer. Furthermore, due to the suitable firing temperature, the surface is free of pinholes, effectively improving anti-fouling performance. Thorough firing results in a sufficiently dense structure, effectively enhancing wear resistance and anti-fouling properties.

[0068] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A metallic-luster ceramic tile, characterized in that, include: The green body layer and the metallic glaze layer attached to the surface of the green body layer, wherein the raw materials for preparing the metallic glaze layer contain phosphorus minerals as a melting aid.

2. The metallic ceramic tile as described in claim 1, characterized in that, The phosphorus-containing mineral is silicon phosphate, which accounts for 4 wt%-7 wt% of the raw material of the metallic glaze by mass percentage.

3. The metallic ceramic tile as described in claim 2, characterized in that, The ratio of P2O5 to SiO2 in the silicon phosphate is 1.5 to 3:1 by mass.

4. The metallic ceramic tile as described in any one of claims 1 to 3, characterized in that, The raw materials for preparing the metallic luster glaze, by mass parts, include: 40-50 parts potassium feldspar, 20-30 parts quartz, 5-10 parts alumina, 5-10 parts calcite, 3-8 parts silicon phosphate, 12-18 parts calcined kaolin, 8-15 parts metal oxide pigment, and 0.3-0.6 parts dispersant. The metal oxide pigment includes one or more of iron oxide, manganese oxide, copper oxide, and cobalt oxide. The dispersant includes one or more of sodium tripolyphosphate, water glass, and ammonium polyacrylate.

5. The metallic ceramic tile as described in claim 4, characterized in that, By weight, an embossed layer is also attached between the body layer and the metallic glaze layer. The raw materials for preparing the embossed layer include: 40-60 parts of albite, 10-15 parts of quartz powder, 3-8 parts of mullite fiber, 8-12 parts of kaolin, 3-6 parts of sodium bentonite, 2-5 parts of barium carbonate, 4-8 parts of zinc oxide, 8-15 parts of zirconium silicate, 0.1-0.3 parts of sodium tripolyphosphate, and 0.05-0.2 parts of carboxymethyl cellulose.

6. The metallic ceramic tile as described in claim 5, characterized in that, A base glaze layer is also attached to the body layer, and the relief layer covers the surface of the base glaze layer. The raw materials for preparing the base glaze layer, by mass, include: 70-80 parts of transparent frit, 13-18 parts of pearlescent powder, 5-10 parts of matting powder, and 0.4-0.8 parts of carboxymethyl cellulose. The chemical composition of the transparent frit includes: 40-55% SiO2, 5-15% Al2O3, 5-15% B2O3, 2-5% Na2O, 1-8% K2O, 3-8% CaO, 1-4% MgO, 3-7% ZnO, and 7-12% ZrO. The pearlescent powder includes one or more of synthetic mica, flaky silica, flaky alumina, and glass flakes. The matting powder includes one or more of talc, diatomaceous earth, and zircon.

7. The metallic ceramic tile as described in claim 6, characterized in that, The raw materials for preparing the green body layer, by mass fraction, include: 30-40 parts of washed kaolin, 15-25 parts of potassium feldspar, 10-20 parts of sodium feldspar, 15-25 parts of quartz sand, 2-5 parts of talc, and 3-6 parts of calcined alumina.

8. The metallic ceramic tile as described in any one of claims 1-7, characterized in that, A transparent wear-resistant protective layer is also attached to the metallic glaze. The raw materials for preparing the transparent wear-resistant protective layer include: 80-90 parts of frit, 5-20 parts of wear-resistant material, and 0.3-0.7 parts of rheology modifier. The chemical composition of the frit includes: 50-65% SiO2, 15-25% Al2O3, 3-10% B2O3, 4-8% CaO, 2-4% MgO, 3-7% ZnO, and 1-3% Li2O. The wear-resistant material includes one or more of cubic boron nitride, white corundum, fused mullite, and micron-sized zirconium oxide. The rheology modifier includes one or more of sodium bentonite, propylene glycol, lithium magnesium silicate, and carboxymethyl cellulose.

9. A method for preparing metallic-luster ceramic tiles, characterized in that, The method for preparing the metallic luster ceramic tile as described in claim 8 includes the following steps: S1. Prepare the green body layer, and apply a base glaze to its surface to prepare a base glaze layer; S2. Print the relief glaze onto the base glaze layer to prepare a patterned relief layer; S3. Apply metallic glaze to the pattern branches and outline edges of the relief layer to prepare the metallic glaze layer, and apply transparent protective glaze to the metallic glaze layer and the relief layer to prepare the transparent wear-resistant protective layer. S4. The glaze blank prepared according to the above steps is sent into the kiln for firing. The firing temperature is controlled at 1180~1280℃ and the firing cycle is 55-80 minutes.

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