Low water absorption ceramic tile for improving ceramic tile bonding strength and preparation method thereof

Abstract

The invention discloses a preparation method of low-water-absorption ceramic tiles with improved bonding strength, comprising the following steps: A. preparing a green body layer; B. applying an isolation and covering glaze on the bottom of the green body layer, wherein the chemical composition of the isolation and covering glaze includes SiO2 39-44%, Al2O3 44-48%, Fe2O3 0.1-0.3%, TiO2 0.05-0.25%, CaO 1.5-2.5%, MgO 2-3.5%, K2O 0-0.6%, Na2O 3.7-4.3% and a loss on ignition 0.5-2%; and C. applying a tile base slurry by a roller on the bottom of the isolation and covering glaze layer, and firing the tile in a kiln to obtain the low-water-absorption ceramic tiles with improved bonding strength, wherein the specific gravity of the tile base slurry is 1.04-1.1. In this case, an isolation covering glaze layer is added to the bottom of the green body layer to improve the bonding strength of the tile laying. In addition to improving the bonding strength of the tiles during laying, it can also play a certain isolation role. It is used to partially replace the existing brick base slurry to avoid the appearance of rods and nails during the firing process, which is beneficial to further improve the bonding strength and laying efficiency of the tiles.

Description

Technical Field

[0001] The present invention relates to the technical field of building ceramics, in particular to a low-water-absorption ceramic tile capable of improving the bonding strength of the ceramic tile and a preparation method thereof. Background Art

[0002] In traditional tile installation, the adhesion between the cement bonding layer and the tile after installation decreases as the tile's water absorption rate (E value) decreases. This is primarily due to the fact that low-water-absorption tiles (E < 0.1%) have a higher degree of sintering, resulting in a smoother, denser surface with fewer micropores and pits. This reduces the firm interlocking between the tile and the cement bonding layer after hydration.

[0003] In addition, large-sized low-water-absorption ceramic tile products have low residual stress after high-temperature firing, making them less likely to deform. The lower deformation causes most of the stress generated at the contact interface between the bottom of the tile and the cement bonding layer to be concentrated in the relatively weak cement bonding layer. At the same time, the use of large-sized ceramic tile products means that there are fewer gaps per unit area, and the deformation gaps available for stress release are reduced. The above factors will cause the cement bonding layer to be subjected to greater forces, making it more susceptible to damage and fracture, and ultimately forming hollowing and falling off during the laying and use of the tiles. On the one hand, hollow ceramic tiles are prone to warping or falling off during use, affecting the decorative effect; on the other hand, when hollowing occurs in water-using areas such as balconies, kitchens, and bathrooms, it is easy for water to accumulate in the hollow areas and produce foul odors, seriously affecting the living experience.

[0004] Insufficient bonding strength between ceramic tiles and cement mortar-based adhesives is one of the causes of hollowing. Tile adhesive is a commonly used method to increase the strength of ceramic tiles and adhesives, but its cost is often several times that of ordinary cement mortar, resulting in high construction costs. Furthermore, research on the bonding strength between ceramic tiles and adhesives has revealed that the water absorption rate of the ceramic tile body is a very important factor affecting bond strength. Increasing the water absorption rate of ceramic tiles can effectively reduce the risk of hollowing. Therefore, to ensure that tiles do not slip during laying and remain dense and secure after laying, some manufacturers improve the bonding strength of ceramic tiles by increasing the water absorption rate of the ceramic tiles. However, increased water absorption of ceramic tiles means a decrease in mechanical properties such as the breaking strength and modulus of rupture of the ceramic tile product, which can easily limit the application scenarios and consumer groups of ceramic tile products. Therefore, improving the bonding strength of low-water-absorption ceramic tiles has become a difficult problem in the architectural ceramics industry.

[0005] Furthermore, in modern ceramic tile production, magnesium oxide is typically used as the base slurry. This hydration reaction easily produces magnesium hydroxide, which reacts with sulfides in the kiln flue gas to form magnesium sulfate crystals. At high temperatures, this reacts with the aluminum oxide at the base of the brick and on the surface of the brick rods to form eutectics such as magnesia-alumina spinel. These eutectics are known as "rods" (spiked) that adhere to the brick rods and the brick base. Rods primarily occur in two temperature zones: the pre-heat zone (350-800°C) and the temperature zone between the high-temperature zone and the quenching zone. In the pre-heat zone, the bricks are fired at a lower temperature, before the liquid phase forms, resulting in low strength. If affected by rods at this stage, the bricks can easily run unevenly and break. In the post-heat zone, the bricks soften after passing through the kiln's high temperature zone. If rods are present on the brick rods at this time, the flatness of the bricks can be affected, leading to localized deformation and compromised product shape. Therefore, preventing the presence of rods has become a challenge for the ceramics industry. Summary of the Invention

[0006] The purpose of the present invention is to propose a method for preparing low-water absorption ceramic tiles that improves the bonding strength of ceramic tiles. By adding an isolation covering glaze layer at the bottom of the green body layer to improve the bonding strength of the ceramic tiles during paving, in addition to improving the bonding strength of the ceramic tiles during paving, it can also play a certain isolation role. It is used to partially replace the existing brick base mortar to avoid the appearance of rods and nails during the firing process, which is conducive to further improving the bonding strength and paving efficiency of the ceramic tiles.

[0007] Another object of the present invention is to propose a low-water absorption ceramic tile produced by the above-mentioned preparation method, which improves the bonding strength of the ceramic tile. An isolation and covering glaze layer is added to the bottom of the green body layer to improve the bonding strength of the ceramic tile. It can effectively reduce the hollowing and falling off phenomena formed by the existing low-water absorption ceramic tiles during laying and use, so as to overcome the shortcomings of the existing technology; at the same time, the isolation and covering glaze layer also has excellent covering power and whiteness.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] A method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles comprises the following steps:

[0010] A. Prepare a brick with a water absorption rate of less than 0.1%, and dry it to obtain a green body layer;

[0011] B. applying an isolation covering glaze on the bottom of the green body layer and drying it to obtain an isolation covering glaze layer; wherein the raw materials of the isolation covering glaze are composed of kaolin, calcium magnesium sodium frit, corundum powder and cobalt blue, and the chemical composition of the isolation covering glaze, in terms of mass percentage, includes SiO2 39-44%, Al2O3 44-48%, Fe2O3 0.1-0.3%, TiO2 0.05-0.25%, CaO 1.5-2.5%, MgO 2-3.5%, K2O 0-0.6%, Na2O 3.7-4.3% and loss on ignition 0.5-2%;

[0012] C. Rolling tile base slurry on the bottom of the isolation covering glaze layer, and firing in a kiln to obtain low water absorption tiles with improved tile bonding strength; wherein the raw material of the tile base slurry includes magnesium oxide, and the specific gravity of the tile base slurry is 1.04 to 1.1.

[0013] Preferably, in step B, the specific gravity of the isolation and covering glaze is 1.05 to 1.15.

[0014] Preferably, in step B, the bottom of the green body layer is placed downward, the isolation and covering glaze is applied by spraying, and the amount of the isolation and covering glaze applied is 80-120 g / m2.

[0015] Preferably, in step B, the bottom of the green body layer is placed downward, and the insulating covering glaze is applied by spraying and roller coating, specifically comprising the following steps:

[0016] First, an isolation covering glaze is sprayed on the bottom of the green body layer, and then the isolation covering glaze is roller-coated on the bottom of the green body layer, and after drying, an isolation covering glaze layer is obtained; wherein, the glaze amount in the spraying step is 40 to 80 g / m2, and the glaze amount in the roller coating step is 40 to 80 g / m2.

[0017] Preferably, in step B, the D70 particle size of the corundum powder is 400 to 800 nm.

[0018] Preferably, in step B, the Al2O3 content in the kaolin is ≥33% by mass.

[0019] Preferably, in step B, the total content of CaO and MgO in the isolation and covering glaze is 4.5-5.2% by mass.

[0020] Preferably, in step B, the raw materials of the isolation and covering glaze are composed of 4-6 parts of kaolin, 55-65 parts of calcium magnesium sodium frit, 30-40 parts of corundum powder and 0.05-0.1 parts of cobalt blue in parts by mass.

[0021] Preferably, in step B, an isolation covering glaze is sprayed on the bottom of the green body layer using a spray gun; wherein the aperture of the spray gun is 0.5 mm, the distance between the spray gun and the bottom of the green body layer is 15 cm, and the pressure of the spray gun is 0.3 MPa.

[0022] A low-water-absorption ceramic tile for improving the bonding strength of ceramic tiles is made using the above-mentioned preparation method, comprising a body layer and an isolation and covering glaze layer, wherein the isolation and covering glaze layer is located at the bottom of the body layer, and the glossiness of the isolation and covering glaze layer is at least 3 degrees and the whiteness is at least 17 degrees.

[0023] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0024] 1. By adding an isolation covering glaze layer at the bottom of the green body layer and optimizing the formula structure of the isolation covering glaze layer, the sintering degree of the isolation covering glaze layer is controlled within an appropriate range, thereby achieving the purpose of improving the bonding strength during laying and use.

[0025] 2. The formula system of the isolation covering glaze is designed to be a high-aluminum, high-flux system, which helps the isolation covering glaze layer to have a suitable sintering degree after firing. On the one hand, it can be well bonded with the conventional low-water absorption body layer before and after firing. On the other hand, it can also play an isolation role between the stick and the body layer during the firing process.

[0026] 3. By optimizing the formula structure of the isolation and covering glaze layer and ensuring it has an appropriate sintering degree, it not only improves the bonding strength of the tiles during paving, but also provides a certain degree of isolation. Therefore, in the production process of low-water-absorption tiles in this solution, the addition of the isolation and covering glaze layer can also partially replace the existing magnesia brick base slurry, avoiding the occurrence of nails during the firing process, thereby further improving the bonding strength of the tiles and paving efficiency.

[0027] 4. Further optimize the formula system of the isolation and covering glaze. By generating scattering substances with a larger refractive index in the glaze layer, it is beneficial to simultaneously improve the covering power and whiteness of the isolation and covering glaze layer, so as to enhance the integrity of the tiles, ensure the consistency of the performance and function of the tiles, and meet the needs of customers. DETAILED DESCRIPTION

[0028] A method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles comprises the following steps:

[0029] A. Prepare a brick with a water absorption rate of less than 0.1%, and dry it to obtain a green body layer;

[0030] B. applying an isolation covering glaze on the bottom of the green body layer and drying it to obtain an isolation covering glaze layer; wherein the raw materials of the isolation covering glaze are composed of kaolin, calcium magnesium sodium frit, corundum powder and cobalt blue, and the chemical composition of the isolation covering glaze, in terms of mass percentage, includes SiO2 39-44%, Al2O3 44-48%, Fe2O3 0.1-0.3%, TiO2 0.05-0.25%, CaO 1.5-2.5%, MgO 2-3.5%, K2O 0-0.6%, Na2O 3.7-4.3% and loss on ignition 0.5-2%;

[0031] C. Rolling tile base slurry on the bottom of the isolation covering glaze layer, and firing in a kiln to obtain low water absorption tiles with improved tile bonding strength; wherein the raw material of the tile base slurry includes magnesium oxide, and the specific gravity of the tile base slurry is 1.04 to 1.1.

[0032] In order to effectively reduce the hollowing and falling off phenomena formed during the laying and use of existing low-water-absorption ceramic tiles, this scheme proposes a preparation method for low-water-absorption ceramic tiles that improves the bonding strength of ceramic tiles. By adding an isolation covering glaze layer at the bottom of the green body layer and optimizing the formula structure of the isolation covering glaze layer, the sintering degree of the isolation covering glaze layer is controlled within an appropriate range, thereby achieving the purpose of improving the bonding strength during laying and use.

[0033] Generally speaking, the sintering degree of the glaze layer after firing increases with the increase of the alumina content in the formula system, and decreases with the increase of the solvent content in the formula system. This solution designs the formula system of the isolation covering glaze into a high-aluminum, high-fluxing (calcium, magnesium, potassium, and sodium) system, which helps the isolation covering glaze layer after firing to have a suitable sintering degree. On the one hand, it can be well bonded with the conventional low-water absorption green body layer before and after firing, and on the other hand, it can also play a role in isolating the sticks from the green body layer during the firing process. If the sintering degree of the isolation covering glaze layer is too high, it will be difficult to fire it with the green body layer to form a dense tile structure; if the sintering degree of the isolation covering glaze layer is too low, it will be detrimental to the isolation of the sticks from the tiles.

[0034] In order to avoid the appearance of stick nails, the existing technology generally reduces the usage or specific gravity of magnesium oxide brick mortar as much as possible. However, if the effective ingredients of the brick mortar are reduced, it is difficult to play an isolating role between the stick and the brick. In addition, because the conventional specific gravity of the brick mortar is relatively large and difficult to sinter, after the ceramic tile product is fired, there are unevenly distributed residues with low bonding with the ceramic tile at the bottom. When laying the ceramic tile, the above residues will further reduce the bonding strength between the ceramic tile and the cement adhesive layer, increasing the risk of the ceramic tile falling off. Therefore, in the actual laying process, the decoration construction unit will generally manually clean the brick mortar residue before laying the ceramic tile, which is time-consuming and labor-intensive, and is not conducive to improving the laying efficiency.

[0035] This solution optimizes the formula structure of the isolation and covering glaze layer and makes it have a suitable sintering degree. In addition to improving the bonding strength of the tiles during paving, it can also play a certain isolation role. Therefore, in the production process of the low water absorption ceramic tiles of this solution, the addition of the isolation and covering glaze layer can also partially replace the existing magnesium oxide brick slurry to avoid the appearance of rods and nails during the firing process, thereby further enhancing the bonding strength of the tiles and improving the laying efficiency of the tiles. It should be noted that the specific gravity of the brick slurry in the prior art is generally 1.15 to 1.25, and in the preparation method of this solution, due to the addition of the isolation and covering glaze layer, this case can effectively avoid the appearance of rods and nails by reducing the specific gravity of the brick slurry while ensuring the isolation effect between the sticks and the tiles.

[0036] Furthermore, the color and whiteness of the edge and bottom of the semi-finished ceramic tile body after high-temperature firing (i.e., the unpolished product just out of the oven) are basically the same; while the edge of the finished product after polishing is lighter in color and higher in whiteness, which is quite different from the color and whiteness of the bottom. This is mainly because the edge and bottom of the semi-finished product are directly heated during the firing process, so their sintering degrees are basically the same, and the color and whiteness of the body are basically close; while after the semi-finished product is polished (the polishing amount is about 15mm), the edge position after polishing is relatively less heated during the firing process, resulting in a lower sintering degree at this position compared to the sintering degree of the bottom. Therefore, the whiteness of the edge after polishing is higher than that of the bottom, resulting in the poor integrity of the ceramic tile product. This integrity will be reflected in the performance and function of the ceramic tile product to a certain extent, resulting in differences in performance and function of the same ceramic tile product, which is not conducive to meeting customer needs.

[0037] Therefore, in order to improve the covering power of the glaze layer, this solution further optimizes the formula system of the isolation covering glaze by generating scattering materials with a larger refractive index in the glaze layer to improve the covering effect. Specifically, after the raw materials of the isolation covering glaze layer are fired, the Mg provided by the calcium magnesium sodium frit 2+ and Ca 2+ , will be combined with Al provided by kaolin and corundum powder 3+The kaolin in the raw materials will form magnesium aluminum spinel (MgO·Al2O3) with a refractive index of 1.72 and diopside (CaO·MgO·2SiO2) with a refractive index of 1.68. At the same time, the kaolin in the raw materials will successively form metakaolinite (Al2O3·2SiO2) and silica aluminum spinel (2Al2O3·3SiO2), and finally form mullite (3AlO3·2SiO2) with a refractive index of 1.64. In addition, the calcium magnesium sodium frit itself will also crystallize a small amount of needle-shaped mullite. Furthermore, the corundum powder introduced into the raw materials makes the eutectic glass of the entire formula tend to precipitate a small amount of corundum (α-Al2O3) with a refractive index of 1.76 when the aluminum content of the formula system is relatively high. This is beneficial to simultaneously improve the hiding power and whiteness of the isolation covering glaze layer, so as to improve the integrity of the tiles, ensure the consistency of the performance and function of the tiles, and meet the needs of customers.

[0038] Preferably, the chemical composition of the sodium magnesium calcium frit includes, by mass percentage, SiO2 65.38%, Al2O3 16.64%, Fe2O3 0.31%, TiO2 0.17%, CaO 3.28%, MgO 4.64%, K2O 0.29%, Na2O 6.69% and loss on ignition 1.01%.

[0039] To further illustrate, in step B, the specific gravity of the isolation and covering glaze is 1.05 to 1.15.

[0040] Since the isolation covering layer in this case has a high covering power due to the optimization of the formula structure, the specific gravity of the isolation covering glaze can be reduced while ensuring the covering effect of the glaze layer, so as to be suitable for ceramic products with different thickness ranges.

[0041] To further illustrate, in step B, the bottom of the green body layer is placed downward, the isolation and covering glaze is applied by spraying, and the amount of the isolation and covering glaze applied is 80 to 120 g / m2.

[0042] In a preferred embodiment of the present technical solution, in step B, the green body layer is placed upright (i.e., the top of the green body layer faces upward and the bottom faces downward), and the glaze is applied by spraying the isolated covering glaze upward. As the spraying process continues, the glaze sprayed upward may fall on the top of the green body layer. If the specific gravity of the sprayed glaze is too high, the moisture content of the glaze droplets falling on the surface of the green body layer will decrease after the hot green body is heated, and the amount of dry material remaining on the surface of the green body layer will be large. After high-temperature firing, the dry material may form tiny lumps on the top of the green body layer, affecting its subsequent bonding with the conventional top glaze and eventually forming prickly heat on the glaze surface.

[0043] Since the isolation and covering glaze with optimized formula system in this case has a high hiding power, it can be glazed by spraying while reducing the proportion of isolation and covering glaze. On the one hand, it is beneficial to reduce the risk of low water absorption tiles that enhance the bonding strength of tiles to form prickly heat on the glaze surface. On the other hand, compared with glazing methods such as shower coating and roller coating, the spray glazing method can prevent the introduction of excessive moisture into the green body layer during the glazing process as much as possible, thereby leading to a decrease in the mechanical properties of the green body.

[0044] To further illustrate, in step B, the bottom of the green body layer is placed downward, and the application method of the isolation covering glaze is spraying and roller coating, which specifically includes the following steps:

[0045] First, an isolation covering glaze is sprayed on the bottom of the green body layer, and then the isolation covering glaze is roller-coated on the bottom of the green body layer, and after drying, an isolation covering glaze layer is obtained; wherein, the glaze amount in the spraying step is 40 to 80 g / m2, and the glaze amount in the roller coating step is 40 to 80 g / m2.

[0046] In another preferred embodiment of the present technical solution, the spraying and roller coating methods can be combined to achieve the application of the isolation covering glaze, which can ensure the performance and effect of the tile bottom while ensuring the glaze effect of low water absorption tiles.

[0047] To further illustrate, in step B, the D70 particle size of the corundum powder is 400-800 nm.

[0048] In addition, in order to further enhance the hiding power of the isolation and covering glaze layer, this scheme also optimizes the particle size of the corundum powder used in the raw materials, so that the content of corundum powder with a particle size between 400 and 800 nm accounts for more than 70% of the total content, so that the isolation and covering glaze layer can produce Mie scattering phenomenon that maximizes the scattering effect, thereby achieving the purpose of improving the hiding effect.

[0049] Specifically, the aluminum oxide in this formulation is introduced in the form of corundum (α-Al2O3). During high-temperature firing, a portion of the Al2O3 reacts and contributes to the construction of the silicate glass network, forming an aluminum-containing glass. Simultaneously, at a certain temperature, it crystallizes to form high-refractive-index crystals. The remaining portion of the Al2O3 does not react and remains in the solid solution. By controlling the particle size range of the aluminum oxide, the maximum scattering effect for visible light is achieved. The goal is to prevent particles that are too small, causing light to directly pass through the small particles and diffract, resulting in poor covering effects. At the same time, the goal is to prevent particles that are too large, resulting in poor dispersion of the aluminum oxide in the glaze and non-Mie scattering.

[0050] To further illustrate, in step B, the Al2O3 content in the kaolin is ≥33% by mass.

[0051] Kaolin is a chemical material whose primary mineral is kaolinite. After iron removal and purification, it exhibits extremely high whiteness and aluminum content. It is commonly used to adjust glaze formulations and provide a plasticizing effect. In a preferred embodiment of this scheme, kaolin with an Al2O3 content of 33% or greater is used as a glaze raw material. This facilitates the formation of high-hiding crystals, such as mullite (3AlO3·2SiO2) with a refractive index of 1.64, in an isolated, covering glaze layer.

[0052] To further illustrate, in step B, the total content of CaO and MgO in the isolation and covering glaze is 4.5-5.2% by mass.

[0053] Since the flux content in the formula system has a great influence on the formation of the sintering degree range of the glaze layer, in order to make the sintering degree of the glaze layer better meet the requirements of improving the bonding strength and isolation effect, this scheme further optimizes the total content of CaO and MgO in the isolation covering glaze to 4.5-5.2%.

[0054] To further illustrate, in step B, the raw materials of the isolation and covering glaze are composed of 4 to 6 parts of kaolin, 55 to 65 parts of calcium magnesium sodium frit, 30 to 40 parts of corundum powder and 0.05 to 0.1 parts of cobalt blue, in parts by mass.

[0055] In one embodiment of the present technical solution, the addition amount of each raw material in the isolation and covering glaze layer is optimized, so as to be more conducive to the generation and transformation of the target crystal.

[0056] To further illustrate, in step B, an isolation covering glaze is sprayed on the bottom of the green body layer using a spray gun; wherein, the aperture of the spray gun is 0.5 mm, the distance between the spray gun and the bottom of the green body layer is 15 cm, and the pressure of the spray gun is 0.3 MPa.

[0057] This solution also optimizes the aperture, distance and pressure of the spray gun used for spraying the isolation covering glaze, which is conducive to forming a uniform isolation covering glaze layer at the bottom of the green body layer, further ensuring the continuity of the tile.

[0058] A low-water-absorption ceramic tile for improving the bonding strength of ceramic tiles is made using the above-mentioned preparation method, comprising a body layer and an isolation and covering glaze layer, wherein the isolation and covering glaze layer is located at the bottom of the body layer, and the glossiness of the isolation and covering glaze layer is at least 3 degrees and the whiteness is at least 17 degrees.

[0059] This proposal also proposes a low-water-absorption tile produced using the aforementioned method, enhancing its bonding strength. An insulating and concealing glaze layer is added to the bottom of the base layer to enhance the tile's bonding strength during installation. This effectively reduces the hollowing and shedding that can occur during installation and use of existing low-water-absorption tiles. Furthermore, the insulating and concealing glaze layer achieved in this proposal achieves a sintered glossiness of 3-4 degrees, and a whiteness of at least 75 degrees, approaching the whiteness of the base layer after edge grinding, enhancing the overall appearance of the low-water-absorption tile.

[0060] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0061] Example 1

[0062] A. Prepare a brick with a water absorption rate of less than 0.1%, and obtain a green body layer after drying; the green body layer is prepared from conventional green body raw materials in the ceramic field, and the chemical composition of the green body layer includes, by mass percentage, SiO2 67.85%, Al2O3 17.23%, Fe2O3 1.42%, TiO2 0.23%, CaO 1.18%, MgO 1.65%, K2O 1.85%, Na2O 2.05% and a loss on ignition 4.3%.

[0063] B. The bottom of the green body layer is placed downward, and an isolation covering glaze with a specific gravity of 1.10 and a glaze amount of 80g / ㎡ is sprayed on the bottom of the green body layer, and an isolation covering glaze layer is obtained after drying;

[0064] The raw materials of the isolation and covering glaze layer include kaolin with an Al2O3 content of ≥33%, calcium magnesium sodium frit, corundum powder with a D70 particle size of 400-800nm, titanium dioxide and cobalt blue; in terms of mass percentage, the chemical composition of the isolation and covering glaze layer includes SiO2 39.03%, Al2O3 47.69%, Fe2O3 0.28%, TiO2 0.05%, CaO 1.53%, MgO3.48%, K2O 0.6%, Na2O 3.78% and loss on ignition 2%; in terms of mass percentage, the chemical composition of the calcium magnesium sodium frit includes SiO2 65.38%, Al2O3 16.64%, Fe2O3 0.31%, TiO20.17%, CaO 3.28%, MgO 4.64%, K2O 0.29%, Na2O 6.69% and loss on ignition 1.01%.

[0065] C. Roller-coat the bottom of the isolation covering glaze layer with a magnesium oxide brick base slurry with a specific gravity of 1.07, and after firing in the kiln, obtain low water absorption tiles that improve the bonding strength of the tiles.

[0066] Example 2

[0067] A. Prepare a brick with a water absorption rate of less than 0.1%, and obtain a green body layer after drying; the green body layer is prepared from conventional green body raw materials in the ceramic field, and the chemical composition of the green body layer includes, by mass percentage, SiO2 67.85%, Al2O3 17.23%, Fe2O3 1.42%, TiO2 0.23%, CaO 1.18%, MgO 1.65%, K2O 1.85%, Na2O 2.05% and a loss on ignition 4.3%.

[0068] B. The bottom of the green body layer is placed downward, and an isolation covering glaze with a specific gravity of 1.05 and a glaze amount of 120g / ㎡ is sprayed on the bottom of the green body layer, and an isolation covering glaze layer is obtained after drying;

[0069] The raw materials of the isolation and covering glaze layer include kaolin with an Al2O3 content of ≥33%, calcium magnesium sodium frit, corundum powder with a D70 particle size of 400-800nm, titanium dioxide and cobalt blue; in terms of mass percentage, the chemical composition of the isolation and covering glaze layer includes SiO2 41.64%, Al2O3 46.11%, Fe2O3 0.21%, TiO2 0.1%, CaO 1.97%, MgO 2.79%, K2O 0.2%, Na2O 4.03% and loss on ignition 1.25%; in terms of mass percentage, the chemical composition of the calcium magnesium sodium frit includes SiO2 65.38%, Al2O3 16.64%, Fe2O3 0.31%, TiO2 0.17%, CaO 3.28%, MgO 4.64%, K2O0.29%, Na2O 6.69% and loss on ignition 1.01%.

[0070] C. Roller-coat the bottom of the isolation covering glaze layer with a magnesium oxide brick base slurry of a specific gravity of 1.04, and after firing in the kiln, obtain low water absorption tiles that improve the bonding strength of the tiles.

[0071] Example 3

[0072] A. Prepare a brick with a water absorption rate of less than 0.1%, and obtain a green body layer after drying; the green body layer is prepared from conventional green body raw materials in the ceramic field, and the chemical composition of the green body layer includes, by mass percentage, SiO2 67.85%, Al2O3 17.23%, Fe2O3 1.42%, TiO2 0.23%, CaO 1.18%, MgO 1.65%, K2O 1.85%, Na2O 2.05% and a loss on ignition 4.3%.

[0073] B. The bottom of the green body layer is placed downward, and an isolation covering glaze with a specific gravity of 1.15 and a glaze amount of 40g / m2 is first sprayed on the bottom of the green body layer, and then an isolation covering glaze with a specific gravity of 1.15 and a glaze amount of 40g / m2 is roller-coated on the bottom of the green body layer, and after drying, an isolation covering glaze layer is obtained;

[0074] The raw materials of the isolation and covering glaze layer include kaolin with an Al2O3 content of ≥33%, calcium magnesium sodium frit, corundum powder with a D70 particle size of 400-800nm, titanium dioxide and cobalt blue; in terms of mass percentage, the chemical composition of the isolation and covering glaze layer includes SiO2 43.76%, Al2O3 44.13%, Fe2O3 0.12%, TiO2 0.2%, CaO 2.43%, MgO 2.05%, K2O 0.5%, Na2O 4.28% and loss on ignition 0.6%; in terms of mass percentage, the chemical composition of the calcium magnesium sodium frit includes SiO2 65.38%, Al2O3 16.64%, Fe2O3 0.31%, TiO2 0.17%, CaO 3.28%, MgO 4.64%, K2O0.29%, Na2O 6.69% and loss on ignition 1.01%.

[0075] C. Roller-coat the bottom of the isolation covering glaze layer with a magnesium oxide brick base slurry with a specific gravity of 1.1, and after firing in the kiln, obtain low water absorption tiles that improve the bonding strength of the tiles.

[0076] Control Example

[0077] A low-water-absorption ceramic tile comprises a green body layer, wherein the green body layer is prepared from conventional green body raw materials in the ceramic field, has a water absorption rate of less than 0.1%, and has a chemical composition by mass percentage of SiO2 67.85%, Al2O3 17.23%, Fe2O3 1.42%, TiO2 0.23%, CaO 1.18%, MgO 1.65%, K2O 1.85%, Na2O 2.05% and a loss on ignition of 4.3%.

[0078] The bottom of the green body layer is coated with a magnesia brick base slurry with a specific gravity of 1.15 by roller, and low water absorption ceramic tiles are obtained after firing in a kiln.

[0079] The isolation and covering glaze layers of the low water absorption tiles prepared in Examples 1-3 were subjected to conventional glossiness tests and whiteness tests in the field of architectural ceramics. At the same time, the low water absorption tiles prepared in Examples 1-3 and the low water absorption tiles of the control example were subjected to bonding strength tests and mechanical property tests. The results are shown in Table 1 below:

[0080] Table 1 Performance test results of low water absorption ceramic tiles of Examples 1-3 and Control Example

[0081]

[0082] Among them, the bonding strength test: the prepared low water absorption ceramic tiles are cut into 75mm×75mm test blocks for standby use, and the mortar is prepared according to the standard sand: 325 cement: water = 3:2:1 ingredients, and the mortar is applied to the bottom of the test block to test the 28-day tensile strength.

[0083] The performance test results in Table 1 show that the insulating and concealing glaze layer produced by this formulation has a glossiness of between 3 and 4 degrees. The glaze itself achieves a whiteness of at least 75 degrees after firing. When applied to the bottom of the body layer, it achieves a whiteness close to that of the body layer after edge grinding, ensuring a consistent, low-water-absorption tile appearance and a high modulus of rupture. Furthermore, testing of the paving performance of low-water-absorption tiles with this formulation's insulating and concealing glaze revealed a 28-day pull-out strength of 1.061 MPa, demonstrating excellent bonding performance.

[0084] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will readily conceive of other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the present invention.

Claims

1. A method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles, characterized in that: The following steps are involved: A. Prepare a brick with a water absorption rate of less than 0.1%, and obtain the green body layer after drying; B. applying an isolation covering glaze on the bottom of the green body layer, and obtaining an isolation covering glaze layer after drying; wherein, in terms of weight, the raw materials of the isolation covering glaze include 4-6 parts of kaolin, 55-65 parts of calcium magnesium sodium frit, 30-40 parts of corundum powder, and 0.05-0.1 parts of cobalt blue, and the raw materials of the isolation covering glaze also include titanium dioxide; in terms of weight percentage, the chemical composition of the isolation covering glaze includes SiO2 39-44%, Al2O3 44-48%, Fe2O3 0.1-0.3%, TiO2 0.05-0.25%, CaO 1.5-2.5%, MgO 2-3.5%, K2O 0-0.6%, Na2O 3.7-4.3%, and loss on ignition 0.5-2%; C. Rolling tile base slurry on the bottom of the isolation covering glaze layer, and firing in a kiln to obtain low water absorption tiles with improved tile bonding strength; wherein the raw material of the tile base slurry includes magnesium oxide, and the specific gravity of the tile base slurry is 1.04 to 1.

1.

2. The method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles according to claim 1, characterized in that: In step B, the specific gravity of the isolation and covering glaze is 1.05 to 1.

15.

3. The method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles according to claim 2, characterized in that: In step B, the bottom of the green body layer is placed downward, the isolation and covering glaze is applied by spraying, and the amount of the isolation and covering glaze applied is 80-120 g / m2.

4. The method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles according to claim 1, characterized in that: In step B, the bottom of the green body layer is placed downward, and the insulating and covering glaze is applied by spraying and roller coating, which specifically includes the following steps: First, an isolation covering glaze is sprayed on the bottom of the green body layer, and then the isolation covering glaze is roller-coated on the bottom of the green body layer, and after drying, an isolation covering glaze layer is obtained; wherein, the glaze amount in the spraying step is 40 to 80 g / m2, and the glaze amount in the roller coating step is 40 to 80 g / m2.

5. The method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles according to claim 1, characterized in that: In step B, the D70 particle size of the corundum powder is 400-800 nm.

6. The method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles according to claim 1, characterized in that: In step B, the Al2O3 content in the kaolin is ≥33% by mass.

7. The method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles according to claim 1, characterized in that: In step B, the total content of CaO and MgO in the isolation and covering glaze is 4.5-5.2% by mass.

8. The method for preparing low water absorption ceramic tiles for improving the bonding strength of ceramic tiles according to claim 3 or 4, characterized in that: In step B, an isolation covering glaze is sprayed on the bottom of the green body layer using a spray gun; wherein the aperture of the spray gun is 0.5 mm, the distance between the spray gun and the bottom of the green body layer is 15 cm, and the pressure of the spray gun is 0.3 MPa.

9. A low water absorption ceramic tile for improving the bonding strength of ceramic tiles, characterized in that: It is prepared using the preparation method according to any one of claims 1 to 8, comprising a body layer and an isolation covering glaze layer, wherein the isolation covering glaze layer is located at the bottom of the body layer, and the glossiness of the isolation covering glaze layer is at least 3 degrees and the whiteness is at least 17 degrees.

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