Low water absorption ceramic tile for improving the bonding strength of ceramic tiles and method for manufacturing the same

Abstract

The application discloses a preparation method of low water absorption rate ceramic tiles with improved bonding strength, which comprises the following steps: A, preparing a body layer; B, placing the body layer with the bottom facing down, and spraying an isolation cover glaze on the bottom of the body layer; the chemical composition of the isolation cover glaze comprises 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%; C, polishing the surface of the body layer; D, roll-coating a tile bottom paste with a specific gravity of 1.04-1.1 on the bottom of the isolation cover glaze layer, and entering a kiln for firing. According to the scheme, the isolation cover glaze layer for improving the bonding strength of the ceramic tiles is additionally arranged on the bottom of the body layer, so that the bonding strength of the ceramic tiles during paving can be improved, and the isolation cover glaze layer can also play a certain isolation role, the isolation cover glaze layer is used to partially replace the existing tile bottom paste, the occurrence of a rod nail during the firing process is avoided, and the bonding strength and paving efficiency of the ceramic tiles are further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building ceramics, and particularly relates to a low water absorption rate ceramic tile with improved bonding strength and a preparation method thereof. BACKGROUND

[0002] In traditional ceramic tile paving, the bonding performance between the cement bonding layer after paving and the ceramic tile is lower as the water absorption rate (E value) of the ceramic tile is lower. The main reason is that the sintering degree of the low water absorption rate (E < 0.1%) ceramic tile product is higher, so that the surface layer of the bottom of the ceramic tile is relatively smooth, the density is higher, and the micropores and pits are less, so that the firm embedding formed after the hydration reaction of the ceramic tile and the cement bonding layer is reduced.

[0003] In addition, the residual stress of the large-specification low water absorption rate ceramic tile product after high-temperature sintering is low, so that it is not easy to deform. The lower deformation amount causes the stress generated at the contact interface between the bottom of the ceramic tile and the cement bonding layer to be mostly concentrated in the relatively weak cement bonding layer. At the same time, due to the application of the large-specification ceramic tile product, the joint per unit area is less, and the joint that can supply deformation to release force is reduced. The above factors will cause the cement bonding layer to be subjected to a larger force, thus being more easily damaged and forming a crack, and finally forming a hollowing and falling phenomenon during the ceramic tile paving and use. On the one hand, the hollowed ceramic tile is prone to warping or falling during use, affecting the decorative effect; on the other hand, when the hollowing phenomenon occurs in the water area such as balcony, kitchen and bathroom, water is easy to accumulate at the hollowing position to produce a foul odor, seriously affecting the human living experience.

[0004] The insufficient bonding strength between the ceramic tile and the cement mortar-based bonding agent is one of the reasons for the hollowing. In terms of increasing the strength of the ceramic tile and the bonding agent, ceramic tile glue is a commonly used way, but its cost is often several times that of ordinary cement mortar, and the construction cost is high. In addition, through the study of the bonding strength of the ceramic tile and the bonding agent, it is found that the water absorption rate of the ceramic tile body is a very important factor affecting the bonding strength. Increasing the water absorption rate of the ceramic tile body can effectively reduce the risk of ceramic tile hollowing, so in order to ensure that the ceramic tile does not slip during paving and does not fall after paving, some manufacturers will improve the bonding strength of the ceramic tile by increasing the water absorption rate of the ceramic tile body. However, the increase of the water absorption rate of the ceramic tile body means the decrease of the mechanical performance indicators such as the breaking strength and the modulus of rupture of the ceramic tile product, which easily leads to the limitation of the application scenarios and consumer groups of the ceramic tile product. Therefore, how to improve the paving bonding strength of the low water absorption rate ceramic tile has become a difficult problem in the building ceramic industry.

[0005] Further, in the production process of modern ceramic tiles, magnesium oxide is generally used as the tile bottom paste, which can easily produce magnesium hydroxide through hydration reaction. The substance can easily form magnesium sulfate crystals with sulfides in the flue gas in the kiln, and can easily form co-melting substances such as magnesium-aluminum spinel with aluminum oxide on the bottom of the tile blank and the surface layer of the stick at high temperature zone. The above co-melting substances are the "stick nails" attached to the surface layer of the stick and the tile bottom. The appearance of stick nails mainly concentrates in the temperature zone between the preheating section (350-800℃) of the kiln and the high temperature section and the rapid cooling section. In the former, the tile blank runs in the preheating section of the kiln, and the firing temperature of the preheating section is relatively low. At this time, the tile blank has not appeared liquid phase and thus has low strength. If the tile blank is affected by the stick nails at this time, it is easy to cause the tile blank to run unevenly and be damaged. In the latter, the tile blank is softened after passing through the high temperature zone of the kiln. If there are stick nails on the stick at this time, the flatness of the tile blank will be affected and local deformation will occur, thereby affecting the deformation degree of the product. Therefore, how to avoid the appearance of stick nails has also become a problem in the ceramic industry. SUMMARY

[0006] The purpose of the present application is to provide a preparation method of low water absorption ceramic tile for improving the bonding strength of ceramic tile. By adding an isolation and covering glaze layer for improving the bonding strength of ceramic tile on the bottom of the body layer, the bonding strength of ceramic tile during paving can be improved, and the isolation and covering glaze layer can also play a certain isolation role, which can be used to partially replace the existing tile bottom paste to avoid the appearance of stick nails during the firing process, and is beneficial to further improve the bonding strength and paving efficiency of ceramic tile.

[0007] Another purpose of the present application is to provide a low water absorption ceramic tile for improving the bonding strength of ceramic tile, which is prepared by the above preparation method. The body layer of the tile is provided with an isolation and covering glaze layer for improving the bonding strength of ceramic tile on the bottom of the body layer, which can effectively reduce the hollowing and falling phenomenon of the existing low water absorption ceramic tile during paving and use, so as to overcome the shortcomings of the prior art. At the same time, the isolation and covering glaze layer also has excellent hiding power and whiteness.

[0008] To achieve this purpose, the following technical solutions are adopted in the present application:

[0009] A preparation method of low water absorption ceramic tile for improving the bonding strength of ceramic tile, comprising the following steps:

[0010] A, preparing a tile blank with a water absorption rate of <0.1%, and obtaining a body layer after drying;

[0011] B, the bottom of the body layer is placed downward, and a separating cover glaze is sprayed on the bottom of the body layer to obtain a separating cover glaze layer after drying; wherein the raw materials of the separating cover glaze are composed of kaolin, calcium-magnesium-sodium frit, corundum powder and cobalt blue, and the chemical composition of the separating cover glaze comprises 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% according to mass percentage;

[0012] C, the surface of the body layer with the separating cover glaze layer is polished by using a throwing machine;

[0013] D, a brick bottom paste is roller coated on the bottom of the separating cover glaze layer, and a low water absorption ceramic tile with improved bonding strength is obtained after kiln firing; wherein the raw materials of the brick bottom paste comprise magnesium oxide, and the specific gravity of the brick bottom paste is 1.04-1.1.

[0014] Preferably, in step B, the specific gravity of the separating cover glaze is 1.19-1.21.

[0015] Preferably, in step B, the glazing amount of the separating cover glaze is 50-90 g / m2.

[0016] Preferably, step E is further included, which is located between step C and step D.

[0017] E, a decoration layer is obtained by decorating the surface of the body layer; the decoration step comprises any one and a combination of multiple of the following steps: applying a base glaze, applying a surface glaze, inkjet printing and applying a protective glaze.

[0018] Preferably, in step B, the D70 particle size of the corundum powder is 400-800 nm.

[0019] Preferably, in step B, the Al2O3 content in the kaolin is ≥33% according to mass percentage.

[0020] Preferably, in step B, the total content of CaO and MgO in the separating cover glaze is 4.5-5.2% according to mass percentage.

[0021] Preferably, in step B, the raw materials of the separating cover glaze are composed of kaolin 4-6 parts, calcium-magnesium-sodium frit 55-65 parts, corundum powder 30-40 parts and cobalt blue 0.05-0.1 part according to mass fraction.

[0022] Preferably, in step B, the insulating cover glaze is sprayed on the bottom of the body layer by using a spray gun; wherein the aperture of the spray gun is 0.5mm, the distance between the spray gun and the bottom of the body layer is 15cm, and the pressure of the spray gun is 0.3MPa.

[0023] A low water absorption ceramic tile for improving the bonding strength of the ceramic tile, prepared by the above preparation method, comprising a body layer and an insulating cover glaze layer, wherein the insulating cover glaze layer is located at the bottom of the body layer, the gloss of the insulating cover glaze layer is at least 3 degrees, and the whiteness of the insulating cover glaze layer is at least 17 degrees.

[0024] The technical scheme provided by the embodiments of the present application can have the following beneficial effects:

[0025] 1. By adding an insulating cover glaze layer at the bottom of the body layer and optimizing the formula and structure of the insulating cover glaze layer, the sintering degree of the insulating cover glaze layer is controlled within a suitable range, so as to improve the bonding strength during paving and use.

[0026] 2. The formula system of the insulating cover glaze is designed as a high-aluminum and high-flux system, which helps the insulating cover glaze layer after firing to have a suitable sintering degree, which can on the one hand be well bonded with the conventional low water absorption body layer before and after firing, and on the other hand play a role in isolating the stick and the body layer during firing.

[0027] 3. By optimizing the formula and structure of the insulating cover glaze layer and making it have a suitable sintering degree, the bonding strength of the ceramic tile during paving can be improved, and a certain isolation effect can also be achieved. Therefore, in the production process of the low water absorption ceramic tile of the present scheme, the addition of the insulating cover glaze layer can also partially replace the existing magnesium oxide brick bottom paste, so as to avoid the appearance of stick during firing, thereby further improving the bonding strength and paving efficiency of the ceramic tile.

[0028] 4. The formula system of the insulating cover glaze is further optimized, and by generating scattering substances with large refractive index in the glaze layer, it is beneficial to simultaneously improve the covering power and whiteness of the insulating cover glaze layer, so as to improve the overall performance of the ceramic tile, ensure the consistency of the use performance and function of the ceramic tile, and meet the use requirements of customers. DETAILED DESCRIPTION

[0029] A preparation method of a low water absorption ceramic tile for improving the bonding strength of the ceramic tile, comprising the following steps:

[0030] A. preparing a brick body with a water absorption rate <0.1%, and obtaining a body layer after drying;

[0031] B, the bottom of the body layer is placed downward, and a separating cover glaze is sprayed on the bottom of the body layer to obtain a separating cover glaze layer after drying; wherein the raw materials of the separating cover glaze are composed of kaolin, calcium-magnesium-sodium frit, corundum powder and cobalt blue, and the chemical composition of the separating cover glaze comprises 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% according to mass percentage;

[0032] C, the surface of the body layer with the separating cover glaze layer is polished by a throwing machine;

[0033] D, a brick bottom paste is roller coated on the bottom of the separating cover glaze layer, and a low water absorption ceramic tile with improved bonding strength is obtained after kiln firing; wherein the raw materials of the brick bottom paste comprise magnesium oxide, and the specific gravity of the brick bottom paste is 1.04-1.1.

[0034] In order to effectively reduce the hollowing and falling phenomenon formed in the process of paving and using the existing low water absorption ceramic tile, the present scheme provides a preparation method of a low water absorption ceramic tile with improved bonding strength, by adding a separating cover glaze layer at the bottom of the body layer, and optimizing the formula structure of the separating cover glaze layer, the sintering degree of the separating cover glaze layer is controlled in a suitable range, so as to improve the bonding strength in the process of paving and using.

[0035] Generally speaking, the sintering degree of the fired glaze layer increases with the increase of the aluminum oxide content in the formula system, and decreases with the increase of the content of the fluxing agent in the formula system. The formula system of the separating cover glaze is designed as a high aluminum and high fluxing agent (calcium-magnesium-potassium-sodium) system, which helps the separating cover 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 body layer before and after firing, on the other hand, it can also play a role in isolating the stick and the body layer during the firing process. If the sintering degree of the separating cover glaze layer is too high, it is difficult to form a dense ceramic tile structure with the body layer; if the sintering degree of the separating cover glaze layer is too low, it is not conducive to the isolation of the stick and the ceramic tile.

[0036] In order to avoid the emergence of the stick, the prior art is generally to reduce the amount or specific gravity of the magnesium oxide brick bottom paste as much as possible, but if the effective components of the brick bottom paste are reduced, it is difficult to play a role in isolation between the stick and the brick blank. In addition, due to the large specific gravity of the brick bottom paste and the difficulty in sintering, the bottom of the ceramic tile product is left with unevenly distributed residues after firing, and the residues have low adhesion with the ceramic tile. The above residues can further reduce the adhesion strength between the ceramic tile and the cement adhesive layer during the laying of the ceramic tile, increasing the risk of ceramic tile falling off. Therefore, during the actual laying process, the decoration construction unit generally lays the ceramic tile after manually cleaning the brick bottom paste residues, which is time-consuming and laborious, and is not conducive to improving the laying efficiency.

[0037] The present scheme optimizes the formula structure of the isolation covering glaze layer and makes it have a suitable sintering degree. In addition to improving the adhesion strength of the ceramic tile during laying, it also plays a certain isolation role. Therefore, during the production process of the low water absorption ceramic tile of the present scheme, the addition of the isolation covering glaze layer can also partially replace the existing magnesium oxide brick bottom paste to avoid the emergence of stick during the firing process, thereby further enhancing the adhesion strength of the ceramic tile and improving the laying efficiency of the ceramic tile. It should be noted that the specific gravity of the brick bottom paste in the prior art is generally 1.15-1.25, and in the preparation method of the present scheme, due to the addition of the isolation covering glaze layer, the present scheme can effectively avoid the emergence of stick by reducing the specific gravity of the brick bottom paste while ensuring the isolation between the stick and the ceramic tile.

[0038] Further, the semi-finished product (i.e. the un-edged product just out of the furnace) of the ceramic tile blank after high-temperature firing has a color and whiteness at the edge and the bottom that are basically the same. After edging, the color of the edge of the finished product is light and the whiteness is high, which is quite different from the color and whiteness of the bottom. This is mainly because the edge and the 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 blank are basically close. After edging the semi-finished product (the edging amount is about 15 mm), the edge position after edging receives relatively less heat 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 edging is higher than the whiteness of the bottom, resulting in a poor overall appearance of the ceramic tile product, which to some extent will affect the performance and function of the ceramic tile product, leading to differences in performance and function of the same ceramic tile product, which is not conducive to meeting the customer's usage requirements.

[0039] Therefore, in order to improve the hiding power of the glaze layer, the formula system of the isolation covering glaze is further optimized in the present scheme, and scattering substances with a large refractive index are generated in the glaze layer to improve the hiding effect. Specifically, when the raw materials of the isolation covering glaze layer are fired, the Mg 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.

[0040] 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%.

[0041] It should be further explained that in step B of this solution, the green body layer is placed upright (i.e., the top of the green body layer is facing upward and the bottom is facing downward), and the glaze is applied by spraying the isolation covering glaze upward. Due to the continuous spraying process, 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 be reduced 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 combination with conventional glaze, and eventually forming prickly heat on the glaze surface. Therefore, in order to avoid the occurrence of the above-mentioned glaze defects, this solution is also specially added in the green body throwing step (i.e., step C), and the green body throwing machine is used to throw away the dry material of the isolation covering glaze remaining on the surface of the green body layer to ensure the product quality of low water absorption ceramic tiles.

[0042] To further illustrate, in step B, the specific gravity of the isolation and covering glaze is 1.19 to 1.21.

[0043] Furthermore, since this solution adds a polishing step in the preparation method, the specific gravity of the isolation and covering glaze can be appropriately increased while reducing the risk of glaze defects due to low water absorption, thereby further improving the covering power of the isolation and covering glaze layer.

[0044] Preferably, the specific gravity of the isolation covering glaze is 1.20.

[0045] Further, in step B, the amount of the isolation cover glaze sprayed is 50-90 g / m2.

[0046] In the present application, the proportion of the isolation cover glaze can be appropriately increased while the risk of low water absorption rate and glaze defects is reduced, and thus the amount of the isolation cover glaze can be appropriately reduced while the proportion of the isolation cover glaze is increased, so that the body layer is prevented from being introduced with too much water during the glazing process, thereby preventing the mechanical properties of the body from being reduced.

[0047] Further, step E is included between step C and step D.

[0048] E, decorating the surface of the body layer to obtain a decoration layer; the decoration step includes any one or a combination of multiple of the following: applying a base glaze, applying a surface glaze, inkjet printing, and applying a protective glaze.

[0049] It should be noted that each decoration process in the decoration step is a conventional decoration process in the field of architectural ceramics, which is not described herein.

[0050] Further, in step B, the D70 particle size of the corundum powder is 400-800 nm.

[0051] In addition, in order to further improve the covering power of the isolation cover glaze layer, the particle size of the corundum powder used in the raw materials is also optimized, so that the content of the corundum powder with a particle size of 400-800 nm accounts for more than 70% of the total content, so that the Mie scattering phenomenon of the isolation cover glaze layer is maximized to achieve the purpose of improving the covering effect.

[0052] Specifically, the alumina in the formula system of the present application is introduced in the form of corundum (α-Al2O3). During high-temperature firing, part of the Al2O3 participates in the reaction and participates in the construction of the silicate glass network, forming an aluminum-containing glass body, and at a certain temperature, high-refractive crystals are generated by crystallization; another part of the Al2O3 does not participate in the reaction and remains in the solid solution. By controlling the particle size range of the alumina, the maximum scattering effect of visible light is achieved. It is necessary to prevent the particle size from being too small, so that the light directly penetrates the small particles to produce diffraction phenomenon, resulting in poor covering effect; at the same time, it is also necessary to prevent the particle size from being too large, resulting in poor dispersibility of the alumina in the glaze, and non-Mie scattering phenomenon.

[0053] Further, in step B, the Al2O3 content in the kaolin is ≥33% by mass percentage.

[0054] The kaolin belongs to chemical materials, the main mineral of which is kaolinite, and after iron removal and purification, the whiteness and aluminum content thereof are very high, and the kaolin is generally used for adjusting the formula of glaze and plays a plasticizing role. In an optimal embodiment of the present application, the kaolin with an Al2O3 content of 33% or more is selected as the raw material of the glaze, which is more conducive to the generation of target crystals such as mullite (3AlO3·2SiO2) with high hiding power and a refractive index of 1.64.

[0055] Further, in step B, the total content of CaO and MgO in the isolating and hiding glaze is 4.5-5.2% by mass percentage.

[0056] Since the content of fluxing agent 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 the improvement of the bonding strength and the isolation effect, the total content of CaO and MgO in the isolating and hiding glaze is preferably 4.5-5.2% in the present application.

[0057] Further, in step B, the raw materials of the isolating and hiding glaze consist of kaolin 4-6 parts, calcium-magnesium-sodium frit 55-65 parts, corundum powder 30-40 parts, and cobalt blue 0.05-0.1 part by mass fraction.

[0058] In an embodiment of the present application, the addition amount of each raw material in the isolating and hiding glaze layer is optimized, which is more conducive to the generation and conversion of target crystals.

[0059] Further, in step B, the isolating and hiding glaze is sprayed on the bottom of the body layer by 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 body layer is 15 cm, and the pressure of the spray gun is 0.3 MPa.

[0060] The aperture, distance, and pressure of the spray gun used for spraying the isolating and hiding glaze are also optimized in the present application, which is conducive to the formation of a uniform isolating and hiding glaze layer on the bottom of the body layer and further ensures the through-body property of the ceramic tile.

[0061] A low water absorption ceramic tile with improved bonding strength is prepared by the above preparation method and comprises a body layer and an isolating and hiding glaze layer, wherein the isolating and hiding glaze layer is located at the bottom of the body layer, and the glossiness and whiteness of the isolating and hiding glaze layer are at least 3 degrees and 17 degrees, respectively.

[0062] The scheme also provides a low water absorption ceramic tile with improved bonding strength of ceramic tile, which is prepared by the preparation method and has a base body layer and an isolation covering glaze layer added at the bottom of the base body layer, so that the hollowing and falling phenomena of the existing low water absorption ceramic tile during paving and use can be effectively reduced. In addition, the sintering degree of the isolation covering glaze layer is characterized by gloss, which can reach 3-4 degrees, and the whiteness can reach at least 75 degrees, which is close to the whiteness of the base body layer after edge grinding, so that the overall effect of the low water absorption ceramic tile is improved.

[0063] The technical scheme of the present application will be further described below through specific embodiments.

[0064] Embodiment 1

[0065] A, prepare a brick body with a water absorption rate of <0.1%, and obtain a base body layer after drying; the base body layer is prepared from conventional base body raw materials in the ceramic field, and the chemical composition of the base body layer includes 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 loss on ignition 4.3% according to mass percentage.

[0066] B, place the base body layer with the bottom facing down, spray an isolation covering glaze with a specific gravity of 1.20 and an application amount of 70 g / m2 on the bottom of the base body layer, and obtain an isolation covering glaze layer after drying; wherein the raw materials of the isolation covering glaze include kaolin, calcium-magnesium-sodium clinker, corundum powder, and cobalt blue, and the chemical composition of the isolation covering glaze includes SiO2 39.03%, Al2O3 47.69%, Fe2O3 0.28%, TiO2 0.05%, CaO 1.53%, MgO 3.48%, K2O 0.6%, Na2O 3.78%, and loss on ignition 2% according to mass percentage.

[0067] C, use a throwing machine to polish the surface of the base body layer with the isolation covering glaze layer;

[0068] E, apply a face glaze on the surface of the base body layer to obtain a decoration layer;

[0069] D, roll coat magnesium oxide brick bottom paste with a specific gravity of 1.07 on the bottom of the isolation covering glaze layer, and obtain a low water absorption ceramic tile with improved bonding strength of ceramic tile after kiln firing.

[0070] Embodiment 2

[0071] A, prepare brick blank with water absorption <0.1%, and get the body layer after drying; the body layer is prepared from the body raw material in the ceramic field, and the chemical composition of the body layer includes 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 loss on ignition 4.3% according to mass percentage.

[0072] B, place the bottom of the body layer downward, spray the isolation cover glaze with specific gravity 1.21 and application amount 50g / m2 on the bottom of the body layer, and get the isolation cover glaze layer after drying; wherein the raw material of the isolation cover glaze is composed of kaolin, calcium-magnesium-sodium frit, corundum powder and cobalt blue, and the chemical composition of the isolation cover glaze 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% according to mass percentage;

[0073] C, use the throwing machine to polish the surface of the body layer with the isolation cover glaze layer;

[0074] E, apply the face glaze on the surface of the body layer to get the decoration layer;

[0075] D, roll coat the magnesium oxide brick bottom paste with specific gravity 1.04 on the bottom of the isolation cover glaze layer, and get the low water absorption ceramic tile with improved bonding strength of ceramic tile after kiln firing.

[0076] Example 3

[0077] A, prepare brick blank with water absorption <0.1%, and get the body layer after drying; the body layer is prepared from the body raw material in the ceramic field, and the chemical composition of the body layer includes 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 loss on ignition 4.3% according to mass percentage.

[0078] B, the bottom of the body layer is placed downward, an isolation covering glaze with a specific gravity of 1.19 and an application amount of 90 g / m2 is sprayed on the bottom of the body layer, and an isolation covering glaze layer is obtained after drying; wherein the raw materials of the isolation covering glaze are composed of kaolin, calcium-magnesium-sodium clinker, corundum powder and cobalt blue, and the chemical composition of the isolation covering glaze comprises SiO243.76%, Al2O344.13%, Fe2O30.12%, TiO20.2%, CaO 2.43%, MgO 2.05%, K2O 0.5%, Na2O 4.28% and loss on ignition 0.6% according to mass percentage;

[0079] C, the surface of the body layer with the isolation covering glaze layer is polished by a throwing machine;

[0080] E, a face glaze is applied on the surface of the body layer to obtain a decoration layer;

[0081] D, a magnesium oxide brick bottom paste with a specific gravity of 1.1 is roller coated on the bottom of the isolation covering glaze layer, and a low water absorption ceramic tile with improved bonding strength is obtained after kiln firing.

[0082] Comparative example

[0083] A low water absorption ceramic tile comprises a body layer and a face glaze layer, the face glaze layer is located on the top of the body layer, the face glaze layer is fired from a face glaze, and the face glaze of the examples 1-3 and the comparative example is the same.

[0084] The body layer is prepared from conventional body raw materials in the ceramic field, has a water absorption of <0.1%, and the chemical composition of the body layer comprises 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 loss on ignition 4.3% according to mass percentage.

[0085] A magnesium oxide brick bottom paste with a specific gravity of 1.15 is roller coated on the bottom of the body layer, and a low water absorption ceramic tile is obtained after kiln firing.

[0086] The glaze surface effect of the low water absorption ceramic tiles prepared in the examples 1-3 and the comparative example is observed, the low water absorption ceramic tiles prepared in the examples 1-3 are respectively subjected to the conventional glossiness test and whiteness test in the technical field of building ceramics, and the bonding strength test and the mechanical property test are performed on the low water absorption ceramic tiles prepared in the examples 1-3 and the low water absorption ceramic tile of the comparative example, and the results are shown in Table 1 as follows:

[0087] Table 1 Performance test results of the low water absorption ceramic tiles of the examples 1-3 and the comparative example

[0088]

[0089] In which, the bonding strength test: the prepared low water absorption ceramic tile is cut into 75mmx75mm test block for standby, the mortar is prepared according to the standard sand: 325 cement: water = 3:2:1, the mortar is applied to the bottom of the test block, and the 28-day pull strength is tested.

[0090] From the performance test results of table 1, it can be known that the gloss of the isolation cover glaze layer obtained from the formula structure of the present application is between 3-4 degrees; and the whiteness of the glaze itself after firing can reach at least 75 degrees, which is close to the whiteness of the ground body layer after grinding, ensuring the overall effect of the low water absorption ceramic tile, and also having a high modulus of rupture. At the same time, the paving effect of the low water absorption ceramic tile with the isolation cover glaze layer of the present application is tested, and the 28-day pull strength is as high as 1.036MPa, and the bonding performance is excellent.

[0091] The technical principles of the present application are described above in combination with specific embodiments. These descriptions are only for explaining the principles of the present application, and cannot be explained as limiting the protection scope of the present application in any way. Based on the explanations herein, other specific embodiments of the present application can be conceived by those skilled in the art without creative labor, and these embodiments will fall within the protection scope of the present application.

Claims

1. A method for producing a low water absorption ceramic tile having improved tile adhesion strength, characterized by, It comprises the following steps: A. Prepare green bricks with a water absorption rate <0.1%, and obtain a green body layer after drying; B. Place the bottom of the green body layer downward, spray a separating cover glaze on the bottom of the green body layer, and obtain a separating cover glaze layer after drying; wherein the raw materials of the separating cover glaze are composed of kaolin, calcium-magnesium-sodium clinker, corundum powder and cobalt blue, and the chemical composition of the separating cover glaze comprises 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% according to mass percentage; C. Use a throwing machine to polish the surface of the green body layer with the separating cover glaze layer; D. Roll coat a brick bottom paste on the bottom of the separating cover glaze layer, and obtain a low water absorption ceramic tile with improved bonding strength after kiln firing; wherein the raw materials of the brick bottom paste comprise magnesium oxide, and the specific gravity of the brick bottom paste is 1.04-1.1; In step B, the specific gravity of the separating cover glaze is 1.19-1.21; and the raw materials of the separating cover glaze are composed of kaolin 4-6 parts, calcium-magnesium-sodium clinker 55-65 parts, corundum powder 30-40 parts and cobalt blue 0.05-0.1 part according to mass fraction.

2. The method of claim 1, wherein the low water absorption ceramic tile having improved bonding strength is prepared by adding 0.1 to 0.5 wt% of the compound of claim 1 to a ceramic tile body. In step B, the amount of the separating cover glaze sprayed is 50-90 g / m2.

3. The method of claim 1, wherein the low water absorption ceramic tile having improved bonding strength is prepared by adding 0.1 to 0.5 wt% of the compound of claim 1 to a ceramic tile body. It further comprises step E, which is located between step C and step D; E. Decorate the surface of the green body layer to obtain a decoration layer; the decoration step comprises any one and a combination of multiple of the following steps: applying a base glaze, applying a surface glaze, inkjet printing and applying a protective glaze.

4. The method of claim 1, wherein the low water absorption ceramic tile having improved bonding strength is prepared by adding 0.1 to 0.5 wt% of the compound of claim 1 to a ceramic tile body. In step B, the D70 particle size of the corundum powder is 400-800 nm.

5. The method of claim 1, wherein the low water absorption ceramic tile having improved bonding strength is prepared by adding 0.1 to 0.5 wt% of the compound of claim 1 to a ceramic tile body. In step B, the Al2O3 content in the kaolin is ≥33% according to mass percentage.

6. The method of claim 1, wherein the low water absorption ceramic tile having improved bonding strength is prepared by adding 0.1 to 0.5 wt% of the compound of claim 1 to a ceramic tile body. In step B, the total content of CaO and MgO in the separating cover glaze is 4.5-5.2% according to mass percentage.

7. The method of claim 1, wherein the low water absorption ceramic tile having improved bonding strength is prepared by adding 0.1 to 0.5 wt% of the compound of claim 1 to a ceramic tile body. In step B, use a spray gun to spray the separating cover glaze on the bottom of the green body layer; 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.

8. A low water absorption ceramic tile having improved tile adhesion strength, characterized in that, The low water absorption ceramic tile with improved bonding strength is prepared by using the preparation method of any one of claims 1-7, and comprises a green body layer and a separating cover glaze layer, the separating cover glaze layer is located at the bottom of the green body layer, and the gloss of the separating cover glaze layer is at least 3 degrees and the whiteness is at least 17 degrees.

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