Gas-phase opaque ground coat, ceramic tile and preparation method of gas-phase opaque ground coat

Abstract

The invention provides a gas-phase opaque ground coat, a ceramic tile and a preparation method thereof, and the gas-phase opaque ground coat comprises the following raw materials by mass: 8-15% of kaolin, 10-20% of potassium feldspar, 25-45% of potassium-sodium feldspar for a blank, 10-32% of frit, 8-15% of quartz, and 5-12% of calcined talc. The gas-phase opaque ground coat can avoid miliaria and other defects and has the performance of high whiteness, adjustable expansion coefficient and good color development, and the used raw materials are low in cost.

Description

Technical Field

[0001] This invention relates to the field of ceramic production technology, and in particular to a vapor-phase opaque glaze, ceramic bricks, and their preparation methods. Background Technology

[0002] The surface decoration process of ceramic tiles is mainly divided into two typical processes: "in-glaze decoration" and "overglaze decoration." In the "in-glaze decoration" process, the steps typically involve applying a base glaze, inkjet printing, and applying effect glazes (such as polished glaze, velvet glaze, and matte glaze) before firing. In the "overglaze decoration" process, inkjet printing is performed after applying the base glaze and effect glazes, followed by a protective glaze and firing. The base glaze, as a key layer providing a white base, directly affects the color quality and decorative performance of the final product due to its opaque effect.

[0003] Traditional ceramic base glazes generally use high-refractive-index crystalline phases (such as zirconium silicate and tin oxide) as opacifiers, utilizing the refractive index difference between the crystalline phase and the glassy phase to achieve a milky white effect through light scattering; for example... Figure 1 As shown.

[0004] However, the high cost of opacifiers such as zirconium silicate and tin oxide leads to an increase in the cost of opacified base glazes.

[0005] Therefore, existing technologies have shortcomings and need to be improved and developed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a vapor-phase opaque base glaze, ceramic brick and its preparation method, in view of the above-mentioned defects of the prior art, so as to solve the problem that the cost of the opaque base glaze is high due to the high cost of the opaque agent in the prior art.

[0007] The technical solution adopted by this invention to solve the technical problem is as follows: The first aspect of this application provides a vapor-phase opaque base glaze, wherein the raw materials of the vapor-phase opaque base glaze, by mass percentage, include: Kaolin 8-15%, potassium feldspar 10-20%, potassium-sodium feldspar for billets 25-45%, frit 10-32%, quartz 8-15%, calcined talc 5-12%.

[0008] In one embodiment of this application, The chemical composition of the kaolin, by mass percentage, includes: Loss on ignition: 11.92-13.63%, SiO2: 46.12-52.37%, Al2O3: 33.43-37.57%, Fe2O3: 0.50-0.88%, TiO2: 0.24-0.50%, CaO: 0.12-0.39%, MgO: 0.10-0.26%, K2O: 0.45-0.76%, Na2O: 0.05-0.22%; The chemical composition of the potassium-sodium feldspar used for the billet, by mass percentage, includes: Loss on ignition: 0.62~1.50%, SiO2: 75.6~80.46%, Al2O3: 11.52~13.31%, Fe2O3: 0.05~0.08%, TiO2: 0.01~0.05%, CaO: 0.29~0.50%, MgO: 0.05~0.15%, K2O: 1.89~2.85%, Na2O: 3.64~4.85%; The chemical composition of the calcined talc, by mass percentage, includes: Loss on ignition: 0.23~0.84%, SiO2: 59.16~67.31%, Fe2O3: 0.12~0.28%, CaO: 0.56~1.50%, MgO: 30.21~33.55%; The chemical composition of the quartz, by mass percentage, includes: Loss on ignition: 0.22-0.32%, SiO2: 96.88-98.79%, Al2O3: 0.89-1.58%, Fe2O3: 0.02-0.05%, TiO2: 0.01-0.05%, CaO: 0.10-0.29%, MgO: 0.08-0.15%, K2O: 0.06-0.10%, Na2O: 0.12-0.32%.

[0009] In one embodiment of this application, the chemical composition of the melt, by mass percentage, includes: SiO259.73~63.13%, Al2O311.51~13.48%, ZrO23.22~5.25%, Fe2O30.06~0.15%, CaO7.07~8.55%, MgO3.74~5.57%, K2O 4.33~5.79%, Na2O 1.96~2.84%.

[0010] In one embodiment of this application, the gloss of the fused block is 40 to 70 degrees.

[0011] In one embodiment of this application, the vapor-phase opaque base glaze further includes a pore-forming agent, which includes one or more of silicon carbide, silicon nitride, aluminum nitride, boron carbide, and boron nitride.

[0012] In one embodiment of this application, the whiteness of the vapor-phase opaque base glaze is 70-72 degrees.

[0013] A second aspect of this application provides a method for preparing ceramic bricks, comprising: The fumed glaze described above is applied to the ceramic body to obtain the glaze layer. Apply a release glaze to a ceramic body that has already been glazed with a base glaze to obtain a release glaze layer; After inkjet printing and glazing on the isolation glaze layer, it is fired at a temperature of 1150~1230℃.

[0014] In one embodiment of this application, the fineness of the vapor-phase opaque base glaze is 0.2-0.4% residue on a 325-mesh sieve, the specific gravity of the glaze slurry is 1.70-1.75, and the amount of base glaze applied during glazing is 350-450 grams per square meter.

[0015] In one embodiment of this application, the gloss level of the ceramic tile is 3.5 to 5.

[0016] A third aspect of this application provides a ceramic tile, wherein the ceramic tile is prepared by the ceramic tile preparation method described above.

[0017] The beneficial effects of this application are as follows: This invention provides a fumed emulsion base glaze, ceramic tiles, and a method for preparing the same. The raw materials of the fumed emulsion base glaze, by mass percentage, include: 8-15% kaolin, 10-20% potassium feldspar, 25-45% potassium-sodium feldspar for the body, 10-32% frit, 8-15% quartz, and 5-12% calcined talc. The fumed emulsion base glaze of this application can avoid defects such as prickly heat, and has the properties of high whiteness, adjustable coefficient of expansion, and good color development, while using relatively low-cost raw materials. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the scattering model of ceramic glaze.

[0019] Figure 2 This is a flowchart of a preferred embodiment of a method for preparing ceramic bricks according to the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0021] Traditional ceramic base glazes generally use high refractive index crystalline phases (such as zirconium silicate, tin oxide, etc.) as opacifiers, utilizing the refractive index difference between the crystalline phase and the glass phase to achieve a milky white effect through light scattering.

[0022] According to Mie scattering theory, the optimal particle size range for opacifying effects is approximately 0.06–0.6 micrometers, and the greater the difference in refractive index, the stronger the opacifying ability. Table 1 classifies opacifiers suitable for silicate glass media (n=1.5).

[0023] Table 1

[0024] As the cost of traditional opacifiers such as zirconium silicate rises, the industry has begun to use corundum, titanite, and other alternative materials, but their formulation design and process control still face challenges.

[0025] In the glaze emulsification mechanism, gas phase emulsification is theoretically feasible, that is, light scattering is caused by introducing tiny bubbles (diameter less than 0.1 mm). However, due to the difficulty in process control, the bubbles are prone to agglomeration and growth, leading to glaze surface defects.

[0026] This application provides a vapor-phase opaque base glaze, which aims to solve the problems of bubble stability and aggregation inhibition, thereby reducing the technical difficulty of the base glaze process and reducing the cost of the opaque base glaze.

[0027] This application provides a vapor-phase opaque base glaze, wherein the raw materials of the vapor-phase opaque base glaze, by mass percentage, include: Kaolin 8-15%, potassium feldspar 10-20%, potassium-sodium feldspar for billets 25-45%, frit 10-32%, quartz 8-15%, calcined talc 5-12%.

[0028] In this application, the fumed glaze used in the embodiments must have a high high-temperature viscosity and no longer uses opacifiers such as zirconium silicate. When the high-temperature viscosity of the glaze is low, bubbles will naturally aggregate and gradually grow. This application applies fumed glaze technology to the base glaze, which can effectively avoid the problem of bubble aggregation in the glaze layer.

[0029] Specifically, during the firing process, ceramic glazes undergo a series of stages depending on temperature changes, including oxidation decomposition, solid-state reaction, sintering, melting, phase separation, and crystallization. After the glaze melts, it produces a large amount of liquid phase. At high temperatures, the glaze slurry resembles hot magma and is highly fluid. If air bubbles are present in the glaze slurry at this point, they will aggregate and eventually form larger bubbles, resulting in a glaze surface quality that fails to meet requirements.

[0030] During firing, the base glaze only needs to be fired to a sintered state. As a glaze layer that isolates the ceramic tile from the body, the base glaze provides a white substrate for inkjet printing, and is typically required to be sintered just to be waterproof and stain-resistant. Since the base glaze is only in a sintered state and not melted, there is no condition for air bubbles in the glaze layer to accumulate. Therefore, this application employs vapor-phase emulsification technology in the base glaze of ceramic tiles.

[0031] In the vapor-phase opaque base glaze formula of this application, an appropriate amount of quartz is introduced to adjust the expansion coefficient of the base glaze, so that the glaze is just sintered and impermeable to water. Kaolin, potassium feldspar, potassium-sodium feldspar for body, quartz, calcined talc, etc., are all natural minerals that have been refined.

[0032] The firing process of vapor-phase opaque base glaze is as follows: batching → wet ball milling → fineness and flow rate testing → flow rate adjustment → slurry discharge → conveying to the glaze line for glazing → firing → obtaining ceramic tile products.

[0033] The vapor-phase opaque base glaze of this application can avoid defects such as prickly heat, and has the properties of high whiteness, adjustable coefficient of expansion, and good color development, and the raw materials used are relatively inexpensive.

[0034] In this embodiment of the application, the chemical composition of the kaolin, by mass percentage, includes: Loss on ignition: 11.92-13.63%, SiO2: 46.12-52.37%, Al2O3: 33.43-37.57%, Fe2O3: 0.50-0.88%, TiO2: 0.24-0.50%, CaO: 0.12-0.39%, MgO: 0.10-0.26%, K2O: 0.45-0.76%, Na2O: 0.05-0.22%.

[0035] In one example, the chemical composition of the kaolin, by mass percentage, includes: Loss on ignition: 13.63%, SiO2: 46.12%, Al2O3: 37.57%, Fe2O3: 0.88%, TiO2: 0.24%, CaO: 0.22%, MgO: 0.16%, K2O: 0.76%, Na2O: 0.12%, balance: impurities; The chemical composition of the potassium-sodium feldspar used for the billet, by mass percentage, includes: Loss on ignition: 0.62-1.50%, SiO2: 75.6-80.46%, Al2O3: 11.52-13.31%, Fe2O3: 0.05-0.08%, TiO2: 0.01-0.05%, CaO: 0.29-0.50%, MgO: 0.05-0.15%, K2O: 1.89-2.85%, Na2O: 3.64-4.85%.

[0036] In one example, the chemical composition of the blank using potassium-sodium feldspar, by mass percentage, includes: Loss on ignition: 0.72%, SiO2: 79.46%, Al2O3: 12.31%, Fe2O3: 0.06%, TiO2: 0.01%, CaO: 0.49%, MgO: 0.07%, K2O: 2.13%, Na2O: 4.35%, with the balance being impurities.

[0037] The chemical composition of the calcined talc, by mass percentage, includes: Loss on ignition: 0.23-0.84%, SiO2: 59.16-67.31%, Fe2O3: 0.12-0.28%, CaO: 0.56-1.50%, MgO: 30.21-33.55%.

[0038] In one example, the chemical composition of the calcined talc, by mass percentage, includes: Loss on ignition: 0.74%, SiO2: 63.31%, Fe2O3: 0.19%, CaO: 1.48%, MgO: 33.55%, with the balance being impurities.

[0039] The chemical composition of the quartz, by mass percentage, includes: Loss on ignition: 0.22-0.32%, SiO2: 96.88-98.79%, Al2O3: 0.89-1.58%, Fe2O3: 0.02-0.05%, TiO2: 0.01-0.05%, CaO: 0.10-0.29%, MgO: 0.08-0.15%, K2O: 0.06-0.10%, Na2O: 0.12-0.32%.

[0040] In one example, the chemical composition of the quartz, by mass percentage, includes: Loss on ignition: 0.32%, SiO2: 97.79%, Al2O3: 1.08%, Fe2O3: 0.02%, TiO2: 0.01%, CaO: 0.12%, MgO: 0.08%, K2O: 0.06%, Na2O: 0.22%, balance being impurities.

[0041] Kaolin can enhance the glaze's resistance to chemical erosion, improve its elasticity, reduce its expansion coefficient, improve the suspension of the glaze slurry, and enhance the adhesion of the glaze to the body.

[0042] Potassium oxide and sodium oxide in the potassium-sodium feldspar used for the body are natural fluxes. These components lower the melting temperature of the glaze, allowing the glaze layer to mature simultaneously with the body during firing. At high temperatures, the potassium-sodium feldspar melts into feldspar glass, filling the spaces between the body particles, causing them to bond and the body to become denser. Simultaneously, as a liquid medium, the feldspar glass promotes the melting and interpenetration of quartz and kaolinite minerals, accelerating the formation and development of mullite crystals and improving the mechanical strength of the body.

[0043] Burning talc can lower the melting temperature and high-temperature viscosity of the glaze, enhance its opacity, improve its whiteness, promote the formation of the intermediate layer between the body and the glaze, and optimize the bonding between the body and the glaze. Quartz can enhance the hardness and chemical stability of the glaze surface.

[0044] In one embodiment of this application, the chemical composition of the melt, by mass percentage, includes: SiO259.73~63.13%, Al2O311.51~13.48%, ZrO23.22~5.25%, Fe2O30.06~0.15%, CaO7.07~8.55%, MgO3.74~5.57%, K2O 4.33~5.79%, Na2O 1.96~2.84%.

[0045] The chemical composition of the fused block, by mass percentage, includes: The composition is as follows: SiO2 62.13%, Al2O3 11.51%, ZrO2 5.25%, Fe2O3 0.1%, CaO 8.07%, MgO 5.17%, K2O 5.79%, Na2O 1.96%, with the balance being impurities.

[0046] Specifically, to ensure stable production, the quality of the fused ingot must be controlled more precisely. Therefore, it is necessary to test the chemical composition of the fused ingot powder. It is also stipulated that the fluctuation range of silicon and aluminum content in the fused ingot must be within 0.6%, and the fluctuation range of calcium, magnesium, potassium, sodium, and other components must be within 0.3%.

[0047] The frit in this application contains ZrO2, a key component of opaque glazes. Its refractive index is significantly higher than that of the glass phase, forming microcrystals within the glaze layer. Through light scattering, this results in an opaque, opaque glaze surface. The frit contains 5.25% ZrO2, effectively masking the body color, enhancing whiteness, and strengthening the glaze's hiding power. SiO2, as a glass forging, together with Al2O3, forms the skeletal structure of the glaze layer, improving its melting and chemical stability. Al2O3 also inhibits excessive ZrO2 crystal growth, preventing roughness caused by overly large crystals and ensuring a fine and uniform opaque effect. MgO and CaO, as network-modifying oxides, reduce the high-temperature viscosity of the glaze, promoting its flow and ensuring uniform coverage of the body. Simultaneously, they inhibit abnormal ZrO2 grain growth, forming fine and uniform opaque crystals, further enhancing the glaze's mechanical strength and impact resistance. K₂O and Na₂O, acting as fluxes, can lower the melting temperature of the glaze and broaden the firing temperature range. This wider melting range allows for a more uniform stress distribution in the glaze layer during cooling, reducing cracking or peeling caused by thermal stress. The glass network structure formed by SiO₂ and Al₂O₃ exhibits excellent chemical stability and resists acid and alkali corrosion.

[0048] In the embodiments of this application, the gloss of the fused block is 40 to 70 degrees.

[0049] During the preparation of the frit, a temperature measuring ring is used to monitor the temperature inside the kiln to ensure that the actual firing temperature is within the range of 1100~1130℃.

[0050] Specifically, when selecting frit, single-fired frit does not crystallize, and the gloss of the frit should be between 40 and 70 degrees. If the gloss is below 40 degrees, the temperature of the frit is too high, making it difficult for the pore-forming agent to react, resulting in poor opacification. If the gloss is above 70 degrees, the high-temperature viscosity of the frit glaze is low, making it easy for the pore-forming agent to react too quickly and causing bubble aggregation.

[0051] In one embodiment of this application, the vapor-phase opaque base glaze further includes a pore-forming agent, which includes one or more of silicon carbide, silicon nitride, aluminum nitride, boron carbide, and boron nitride.

[0052] Among the various components of a pore-forming agent, its selection is crucial. Generally, scatterers in the glaze layer with a particle size equal to or slightly larger than the wavelength of visible light (400-700 nm) possess strong scattering capabilities, resulting in a better opacifying effect. Since carbides or nitrides oxidize in the glaze, releasing gases, they typically create bubbles larger than their particle size within the glaze layer. Therefore, this application selected pore-forming agents with a particle size below 400 nm for testing. Comparative experiments revealed that nitrides or carbides with a particle size of 100-200 nm exhibited better opacifying effects. Materials below 100 nm are more prone to agglomeration, leading to uncontrolled bubbles on the glaze surface during use, resulting in both closed and open bubbles.

[0053] Specifically, this application selects a pore-forming agent from six materials—silicon carbide, boron carbide, aluminum carbide, silicon nitride, boron nitride, and aluminum nitride—that can react with the glaze at high temperatures. Among them, boron nitride, also known as white graphite, has a wide range of applications and the lowest cost. Specifically, hexagonal boron nitride, as a high-temperature lubricating material, has low hardness and is easier to process into nanoscale compared to other hard refractory materials such as carbides or nitrides. Among the pore-forming agents selected in this application, nanoscale hexagonal boron nitride has the lowest price. Furthermore, because only one-thousandth of it needs to be added to the glaze to achieve a whiteness of around 70 degrees, hexagonal boron nitride offers the best cost-performance ratio. Its formulation cost is lower than that of zirconium silicate opaque base glaze, making it one of the options for ceramic tile manufacturers to reduce the cost of base glaze formulations.

[0054] Carbides and nitrides, as common refractory materials, high-hardness materials, or lubricants, exhibit extremely high stability at high temperatures. Their suitability as refractory materials stems from the fact that their surfaces, after oxidation, are covered with a layer of SiO2 or Al2O3. This layer isolates them from air, preventing significant oxidation until temperatures reach 800℃, or even above 1000℃ and 1100℃. However, this extremely thin silicon or aluminum layer can be melted by fluxes in the presence of other materials, thus losing its protection and leading to rapid oxidation. This is the fundamental principle behind the preparation of foam ceramics.

[0055] Based on this principle, introducing a floc that can melt at high temperatures into the base glaze allows carbides or nitrides to continuously release gas at high temperatures, without causing the base glaze to have an excessively high gloss.

[0056] In other words, if the melting temperature of the frit is too high, the reaction of carbides or nitrides in the base glaze will not be sufficient. This will result in insufficient opacity in the base glaze and fluctuations in its whiteness due to temperature changes during use. Conversely, if the melting temperature of the frit is too low, the reaction of carbides or nitrides in the base glaze will be too low, significantly reducing the viscosity of the glaze and making it prone to bubble aggregation, leading to problems such as closed or open bubbles.

[0057] In the embodiments of this application, the whiteness of the vapor-phase opaque base glaze is 70~72 degrees.

[0058] The fumed emulsion base glaze provided in this application exhibits a very strong fumed effect. Only 0.8 to 1.4 parts of pore-forming agent are needed in 1000 parts of fumed emulsion base glaze, i.e., the mass percentage of the pore-forming agent is 0.08 to 0.14%, to obtain ideal whiteness. The formulation variations for different pore-forming agents are as follows: Silicon carbide, silicon nitride, and aluminum nitride, among others, only undergo significant oxidation above 1000℃. The erosion of the surface by the molten frit, which is fired into a liquid phase at high temperatures, causes the carbides or nitrides to form silicon dioxide or aluminum oxide. Since both silicon dioxide and aluminum oxide are high-temperature materials, a larger amount of frit is needed in the formulation of the fumed base glaze to achieve satisfactory whiteness. For example, the raw materials of a fumed base glaze, by weight percentage, include: 10% kaolin, 12% potassium feldspar, 28% potassium-sodium feldspar for the body, 28% frit, 12% quartz, and 10% calcined talc. The pore-forming agent, using a purchased 100-nanometer finished product, is added to 1000 parts of the base glaze. Adding 1 part of the pore-forming agent will achieve a whiteness of 70-72 degrees for the base glaze.

[0059] Boron carbide or boron nitride, for example, begin to oxidize significantly above 800℃. The oxidation reaction proceeds even faster after the frit, fired into a liquid phase at high temperatures, erodes its surface. However, at this point, the base glaze already contains a liquid phase formed from fine frit powder, which encapsulates the microbubbles. Therefore, a smaller amount of frit is needed in the formula to achieve satisfactory whiteness. For example, the raw materials for a vapor-phase opaque base glaze, by weight percentage, include: 10% kaolin, 12% potassium feldspar, 37% potassium-sodium feldspar for the body, 19% frit, 12% quartz, and 10% calcined talc. The pore-forming agent, using a purchased 100-nanometer finished product, is added in a ratio of 1 part to 1000 parts of base glaze, achieving a whiteness of 70-72 degrees.

[0060] This application also provides a method for preparing ceramic tiles, such as... Figure 2 As shown, the method for preparing the ceramic brick includes: Step S100: Apply the vapor-phase emulsion base glaze as described above onto the ceramic body to obtain the base glaze layer; Step S200: Apply a release glaze to the ceramic body that has been coated with a base glaze to obtain a release glaze layer; Step S300: After inkjet printing and surface glazing on the isolation glaze layer, it is fired at a temperature of 1150~1230℃.

[0061] Specifically, it is important to avoid direct contact between the base glaze and the low-viscosity glaze. Otherwise, the surface of the base glaze will react with the low-viscosity glaze, causing a decrease in the high-temperature viscosity of the base glaze surface, leading to the aggregation and growth of bubbles, and ultimately resulting in numerous closed and open bubbles on the glaze surface. Therefore, a protective glaze, such as a commonly used zirconium opaque base glaze or a high-viscosity zirconium-free glaze, needs to be applied over the vapor-phase opaque base glaze. This is followed by inkjet printing and the application of a low-temperature viscosity polished glaze, velvet glaze, or matte glaze.

[0062] For ceramic tiles prepared using the in-glaze technique, the process flow can be adjusted as follows: dry-press ceramic body → clean the body surface → blow off ash and spray water → apply vapor-phase opaque base glaze → spray or print isolation glaze → inkjet printing → apply velvet glaze, full-polished glaze, matte glaze, etc. → kiln firing. This is because the inkjet printing process is after the base glaze application process, and the effect glazes (such as the smooth and lustrous surface of full-polished glaze and velvet glaze, the low gloss of matte glaze, etc.) need to be applied over the inkjet layer.

[0063] After the vapor-phase opaque base glaze is poured onto the ceramic body, a separating glaze is applied by a rubber roller, then the pattern is printed in an inkjet booth, and finally, different surface glazes are applied. After firing at 1150~1230℃, it becomes a qualified ceramic product.

[0064] In the embodiments of this application, the fineness of the vapor-phase opaque base glaze is 0.2~0.4% residue on a 325-mesh sieve, the specific gravity of the glaze slurry is 1.70~1.75, and the amount of base glaze applied during glazing is 350~450 grams per square meter.

[0065] Specifically, the fumed emulsion base glaze is ball-milled to a fineness of 0.2-0.4% residue on a 325-mesh sieve, with a slurry flow rate of about 35 seconds, a glaze slurry specific gravity of 1.70-1.75, and the amount of base glaze applied during glazing is 400±50 grams per square meter.

[0066] The fumed glaze of this application has a fineness of 325 mesh and extremely low residue on the sieve, indicating that the glaze particles are fine and uniform. This allows the fumed glaze to be more fully dispersed in the glaze slurry, forming fine, dense opaque crystals during firing. This enhances the light scattering effect, resulting in a uniform, delicate milky white glaze surface and improved hiding power. The fine-particle glaze slurry of this application has better fluidity, is less prone to sedimentation, and has a more uniform thickness during glazing, reducing color differences or cracking caused by uneven glaze thickness.

[0067] The glaze slurry of this application has a specific gravity of 1.70~1.75, which allows the glaze slurry to quickly adhere to the surface of the body during dipping, spraying, or pouring, reducing dripping or running. The amount of base glaze applied during glazing is 350~450 grams per square meter, which reduces defects such as pinholes and bubbles caused by excessively thick glaze layers, and insufficient covering power caused by excessively thin glaze layers.

[0068] In one embodiment of this application, the gloss level of the ceramic tile is 3.5 to 5.

[0069] The ceramic tile products finally fired in this application have a gloss level of 3.5-5, and the glaze is waterproof. Matte tiles with a gloss level of 3.5-5 have a slightly rough surface, resulting in diffuse light reflection, which effectively disperses light, avoids direct glare, and improves spatial comfort. High-gloss ceramic tiles are prone to specular reflection under strong light, causing glare problems, which may lead to visual fatigue, especially in indoor environments.

[0070] This application also provides a ceramic tile, wherein the ceramic tile is prepared by the ceramic tile preparation method described above.

[0071] The following is a specific example for illustration.

[0072] Example 1: The raw materials of the vapor-phase opaque base glaze in this embodiment, by weight percentage, include: Kaolin 10%, potassium feldspar 12%, potassium sodium feldspar for billets 37%, frit 19%, quartz 12%, calcined talc 10%.

[0073] The steps for using the vapor-phase opaque base glaze in in-glaze ceramic tiles in this embodiment include: Step S1: Dry-pressing ceramic blank; Step S2: Clean the surface of the ceramic body; Step S3: Blow away ash and spray water on the cleaned ceramic blank surface; Step S4: Apply the vapor-phase opaque base glaze. The amount of base glaze applied during glazing is 400±50 grams per square meter. Step S5: Spray or print the isolation glaze. The isolation glaze uses zirconium silicate opaque base glaze, and the specific gravity is adjusted to 1.22±0.02. Add water bubble CMC and adjust the glaze flow rate to 35±1 seconds for glazing. The glaze application amount is 50~100 grams / square meter (glaze slurry). Step S6: Inkjet printing; Step S7: Applying gold velvet glaze, full polishing glaze, matte glaze, etc. Step S8: Firing in the kiln.

[0074] This invention provides a fumed emulsion base glaze, ceramic tiles, and a method for preparing the same. The raw materials for the fumed emulsion base glaze, by mass percentage, include: 8-15% kaolin, 10-20% potassium feldspar, 25-45% potassium-sodium feldspar for the body, 10-32% frit, 8-15% quartz, and 5-12% calcined talc. The fumed emulsion base glaze of this application avoids defects such as blistering and possesses high whiteness, adjustable coefficient of expansion, and good color development, while using relatively low-cost raw materials.

[0075] 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 vapor-phase opaque base glaze, characterized in that, The raw materials of the vapor-phase opaque base glaze, by mass percentage, include: Kaolin 8-15%, potassium feldspar 10-20%, potassium-sodium feldspar for billets 25-45%, frit 10-32%, quartz 8-15%, calcined talc 5-12%.

2. The vapor-phase opaque base glaze according to claim 1, characterized in that, The chemical composition of the kaolin, by mass percentage, includes: Loss on ignition: 11.92-13.63%, SiO2: 46.12-52.37%, Al2O3: 33.43-37.57%, Fe2O3: 0.50-0.88%, TiO2: 0.24-0.50%, CaO: 0.12-0.39%, MgO: 0.10-0.26%, K2O: 0.45-0.76%, Na2O: 0.05-0.22%; The chemical composition of the potassium-sodium feldspar used for the billet, by mass percentage, includes: Loss on ignition: 0.62~1.50%, SiO2: 75.6~80.46%, Al2O3: 11.52~13.31%, Fe2O3: 0.05~0.08%, TiO2: 0.01~0.05%, CaO: 0.29~0.50%, MgO: 0.05~0.15%, K2O: 1.89~2.85%, Na2O: 3.64~4.85%; The chemical composition of the calcined talc, by mass percentage, includes: Loss on ignition: 0.23~0.84%, SiO2: 59.16~67.31%, Fe2O3: 0.12~0.28%, CaO: 0.56~1.50%, MgO: 30.21~33.55%; The chemical composition of the quartz, by mass percentage, includes: Loss on ignition: 0.22-0.32%, SiO2: 96.88-98.79%, Al2O3: 0.89-1.58%, Fe2O3: 0.02-0.05%, TiO2: 0.01-0.05%, CaO: 0.10-0.29%, MgO: 0.08-0.15%, K2O: 0.06-0.10%, Na2O: 0.12-0.32%.

3. The vapor-phase opaque base glaze according to claim 1, characterized in that, The chemical composition of the fused block, by mass percentage, includes: SiO2 59.73~63.13%, Al2O3 11.51~13.48%, ZrO2 3.22~5.25%, Fe2O3 0.06~0.15%, CaO7.07~8.55%, MgO3.74~5.57%, K2O 4.33~5.79%, Na2O 1.96~2.84%.

4. The vapor-phase opaque base glaze according to claim 1, characterized in that, The gloss of the fused block is 40 to 70 degrees.

5. The vapor-phase opaque base glaze according to claim 1, characterized in that, The vapor-phase opaque base glaze also includes a pore-forming agent, which includes one or more of silicon carbide, silicon nitride, aluminum nitride, boron carbide, and boron nitride.

6. The vapor-phase opaque base glaze according to claim 1, characterized in that, The whiteness of the vapor-phase opaque base glaze is 70-72 degrees.

7. A method for preparing ceramic bricks, characterized in that, include: A base glaze layer is obtained by applying the vapor-phase opaque base glaze as described in any one of claims 1 to 6 onto a ceramic body. Apply a release glaze to a ceramic body that has already been glazed with a base glaze to obtain a release glaze layer; After inkjet printing and glazing on the isolation glaze layer, it is fired at a temperature of 1150~1230℃.

8. The method for preparing ceramic bricks according to claim 7, characterized in that, The fineness of the vapor-phase opaque base glaze is 0.2-0.4% residue on a 325-mesh sieve, the specific gravity of the glaze slurry is 1.70-1.75, and the amount of base glaze applied during glazing is 350-450 grams per square meter.

9. The method for preparing ceramic bricks according to claim 7, characterized in that, The ceramic tile has a gloss level of 3.5 to 5.

10. A ceramic tile, characterized in that, The ceramic tile is prepared by the method for preparing ceramic tiles as described in any one of claims 7 to 9.

Images