Hydrophilic self-cleaning glaze, hydrophilic self-cleaning ceramic tile and method for preparing the same

Abstract

The present application relates to the technical field of building ceramics, and particularly relates to a hydrophilic self-cleaning glaze, a hydrophilic self-cleaning ceramic tile and a preparation method thereof, which comprises the following raw materials: zeolite, quartz, calcite, strontium carbonate, barium carbonate, diatomite, kaolin, borax and aluminum phosphate. The hydrophilic self-cleaning glaze provided by the present application can not only realize excellent and persistent hydrophilic self-cleaning property under the premise of reducing production cost, but also is beneficial to ensuring high permeability, high hardness and high wear resistance, and solves the technical problems of poor persistence of hydrophilic self-cleaning property and high production cost in the prior art.

Description

Technical Field

[0001] This invention relates to the field of building ceramics technology, and in particular to hydrophilic self-cleaning glazes, hydrophilic self-cleaning ceramic tiles, and their preparation methods. Background Technology

[0002] As an important decorative material for everyday homes, ceramic tiles are favored by consumers for their regular geometric shape, stable physical properties and clean visual effect, and are widely used in residential kitchens and bathrooms, public buildings and commercial spaces.

[0003] During use, tiles are prone to accumulating dust, oil stains, and other dirt on their surface due to environmental exposure and human activity. Ordinary wiping is often insufficient for thorough cleaning, and long-term accumulation not only affects aesthetics but can also breed bacteria. Traditional cleaning methods typically rely on chemical cleaners or high-pressure water guns, which are not only inefficient but may also cause wear or corrosion to the tile surface.

[0004] To overcome the above-mentioned defects, existing technologies typically coat the surface of tiles with a hydrophilic self-cleaning coating, forming a hydrophilic self-cleaning coating on the surface of the tile. When water comes into contact with the coating surface, it can spread rapidly (i.e., the static contact angle between water and the coating is small) and form a uniform water film. The water film can penetrate into the interface between dirt and coating, thereby reducing the adhesion of dirt. Under the action of gravity, the continuously flowing water film can carry away and remove dirt from the surface of the tile, achieving the effect of hydrophilic self-cleaning. However, the above methods have the following drawbacks: (1) The hydrophilic self-cleaning coating has poor aging resistance. It is prone to aging when exposed to ultraviolet rays, rain and temperature changes for a long time, which leads to the gradual failure of the hydrophilic self-cleaning function and poor hydrophilic self-cleaning durability; (2) The hydrophilic self-cleaning coating has limited bonding force with the tile substrate. It is easy to peel off under frequent friction or temperature stress, which will also reduce the durability of hydrophilic self-cleaning; (3) The surface of existing tiles generally does not have hydrophilic self-cleaning properties. It is necessary to apply an additional layer of hydrophilic self-cleaning coating to make it have hydrophilic self-cleaning properties. However, applying an additional hydrophilic self-cleaning coating can easily increase production costs and is not conducive to large-scale promotion and application.

[0005] Therefore, how to achieve durable hydrophilic self-cleaning properties while reducing production costs has become an urgent technical challenge. Summary of the Invention

[0006] The purpose of this invention is to propose a hydrophilic self-cleaning glaze that, while reducing production costs, not only achieves excellent and long-lasting hydrophilic self-cleaning properties, but also helps to ensure high transparency, high hardness, and high wear resistance, thus solving the technical problems of poor durability of hydrophilic self-cleaning properties and high production costs in the prior art.

[0007] The second objective of this invention is to provide a method for preparing hydrophilic self-cleaning ceramic tiles. The method is simple and easy to operate, ensuring that the resulting hydrophilic self-cleaning ceramic tiles not only achieve excellent and long-lasting hydrophilic self-cleaning properties while reducing production costs, but also help ensure high transparency, high hardness and high wear resistance.

[0008] The third objective of this invention is to provide a hydrophilic self-cleaning ceramic tile prepared by the above-mentioned method. The static contact angle of the hydrophilic self-cleaning ceramic tile without soaking in boiling water is ≤5°, and the static contact angle after soaking in boiling water for 30 days is ≤10°. The Mohs hardness is 7, and the wear resistance is ≥4 (2100 revolutions). It not only achieves excellent and long-lasting hydrophilic self-cleaning properties, but also helps to ensure high transparency, high hardness, and high wear resistance.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] A hydrophilic self-cleaning glaze, by weight percentage, comprises the following raw materials: 25-35% zeolite, 15-25% quartz, 10-18% calcite, 4-8% strontium carbonate, 3-9% barium carbonate, 6-10% diatomite, 5-7% kaolin, 3-7% borax, and 3-7% aluminum phosphate.

[0011] Furthermore, the quartz has a mesh size of 3000 to 8000 mesh.

[0012] Furthermore, the raw materials include the following by weight percentage: 30% zeolite, 20% quartz, 15% calcite, 6% strontium carbonate, 5% barium carbonate, 8% diatomite, 7% kaolin, 5% borax, and 4% aluminum phosphate.

[0013] A method for preparing a hydrophilic self-cleaning ceramic tile, using the aforementioned hydrophilic self-cleaning glaze, includes the following steps:

[0014] A. After mixing zeolite, quartz, calcite, strontium carbonate, barium carbonate, diatomaceous earth, kaolin, borax and aluminum phosphate evenly, add sodium methyl cellulose, sodium hexametaphosphate and water, ball mill, and sieve to obtain hydrophilic self-cleaning glaze.

[0015] B. Apply the hydrophilic self-cleaning glaze to the surface of the body, dry and fire to obtain hydrophilic self-cleaning ceramic tiles.

[0016] Furthermore, in step A, the specific gravity of the hydrophilic self-cleaning glaze is 1.25 to 1.45.

[0017] Further, in step A, the hydrophilic self-cleaning glaze, calculated by mass percentage, leaves a residue of 0.2-0.4% after passing through a 325-mesh sieve.

[0018] Further, in step A, the amount of water added is 33-50% of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium carboxymethyl cellulose added is 0.4-0.6% of the dry material of the hydrophilic self-cleaning glaze, and the amount of sodium hexametaphosphate added is 0.4-0.8% of the dry material of the hydrophilic self-cleaning glaze.

[0019] Furthermore, in step B, the thickness of the hydrophilic self-cleaning glaze is 0.15–0.3 mm.

[0020] A hydrophilic self-cleaning ceramic tile is prepared using the above-mentioned method for preparing hydrophilic self-cleaning ceramic tiles. The static contact angle of the hydrophilic self-cleaning ceramic tile without soaking in boiling water is ≤5°, and the static contact angle after soaking in boiling water for 30 days is ≤10°. The Mohs hardness is 7 and the wear resistance is ≥4.

[0021] The technical solution provided by this invention may include the following beneficial effects:

[0022] 1. This technical solution, through the synergistic effect of the above-mentioned multiple aspects, enriches the surface of the hydrophilic self-cleaning glaze layer obtained by calcination with hydroxyl groups, strengthens the hydrogen bond adsorption capacity between the hydrophilic self-cleaning glaze layer and water molecules, improves the hydrophilicity of the surface of the hydrophilic self-cleaning glaze layer, and makes it easier for water to spread on the glaze surface and form a uniform water film, thereby removing and cleaning the dirt on the surface of the tile, thus improving the hydrophilic self-cleaning performance.

[0023] 2. Diatomaceous earth is a siliceous sedimentary rock with large pores composed of micron-sized pores and a huge specific surface area. Zeolite is a crystalline aluminosilicate mineral with regular, uniform nanoscale pores and channels within its crystal structure. This technical solution uses fluxes such as borax to control the timing and viscosity of the liquid phase. This liquid phase can firmly bond and "anchor" diatomaceous earth and zeolite in the glaze layer without completely dissolving the diatomaceous earth and zeolite particles and preventing the complete collapse of their pore structures. It also allows diatomaceous earth to retain some of its inherent micron-sized pores, and zeolite to retain some of its inherent nanoscale pores. Together, they construct a highly efficient three-dimensional hydrophilic network: diatomaceous earth, with its large pore size and huge specific surface area, acts as a "high-speed waterway" and "reservoir," rapidly capturing and temporarily storing large amounts of water through capillary action. Subsequently, this water is transported to the surrounding zeolite region, where the zeolite utilizes the strong adsorption properties of its nanopores and the ion exchange capacity of its surface cations (such as Na+ cations in zeolite). + and Ca 2+ (Through ion exchange, it can interact strongly with water molecules), achieving precise capture and powerful locking of water molecules. This process forms a continuous mechanism from physical water storage to chemical adsorption, which together significantly enhances the hygroscopic, spreading, and permeable capabilities of the glaze, thus endowing it with excellent hydrophilic self-cleaning properties.

[0024] 3. After sintering, the crystalline framework structure of zeolite and diatomaceous earth is partially retained, resulting in a large number of hydrophilic active sites originating from their internal pores (zeolite contributes ion-exchangeable cations and silanol groups, while diatomaceous earth primarily provides abundant surface silanol groups). Due to the huge specific surface area of ​​zeolite (up to hundreds of square meters per gram) and diatomaceous earth, these active sites are exposed at a high density on the glaze surface, and the number of active sites far exceeds that of traditional vitreous glazes. This large number of active sites significantly enhances the hydrophilic self-cleaning properties of the glaze layer. Detailed Implementation

[0025] This technical solution provides a hydrophilic self-cleaning glaze, which, by mass percentage, includes the following raw materials: zeolite 25-35%, quartz 15-25%, calcite 10-18%, strontium carbonate 4-8%, barium carbonate 3-9%, diatomaceous earth 6-10%, kaolin 5-7%, borax 3-7%, and aluminum phosphate 3-7%.

[0026] To achieve long-lasting self-cleaning properties while reducing costs, this technical solution proposes a hydrophilic self-cleaning glaze. By selecting appropriate raw materials, it is possible to achieve not only excellent and long-lasting hydrophilic self-cleaning properties while reducing production costs, but also to ensure high transparency, high hardness, and high wear resistance. This solves the technical problems of poor durability of hydrophilic self-cleaning properties and high production costs in existing technologies.

[0027] Specifically, the raw materials for hydrophilic self-cleaning glazes include zeolite, quartz, calcite, strontium carbonate, barium carbonate, diatomaceous earth, kaolin, borax, and aluminum phosphate. During calcination, calcite (whose main component is calcium carbonate) decomposes to produce calcium oxide, and kaolin decomposes to produce silicon dioxide. Combined with the silicon dioxide introduced by quartz, the hydrophilic self-cleaning glaze layer formed after calcination is rich in silicon dioxide and calcium oxide.

[0028] Furthermore, calcium oxide is composed of calcium ions (CaO). 2+ ) and oxygen ions (O 2- Ionic compounds formed by ionic bonds readily react with moisture in the environment (such as ambient water vapor adsorbed on the surface of raw materials, crystal water bound between glaze components, or moisture introduced during the process) to generate calcium hydroxide (CaO+H2O→Ca(OH)2). The surface of calcium hydroxide contains a large number of highly polar hydroxyl groups, thus giving the surface of the hydrophilic self-cleaning glaze layer obtained by calcination a large number of hydroxyl groups.

[0029] Simultaneously, acidic oxides (such as silicon dioxide) in the formulation system react with basic oxides (such as calcium oxide) to form a silicate network structure (i.e., a glassy phase). Alkali metal oxides (such as calcium oxide) provide alkali metal ions that can break the bridging oxygen bonds between silicon-oxygen tetrahedra in the silicate network structure, causing the silicate network structure to depolymerize and generate negatively charged non-bridging oxygen (Si-O). - Meanwhile, calcium ions in calcium oxide, due to their high charge density, strongly attract the negative charge of non-bridging oxygen and interact strongly with it, further weakening the bridging bonds between adjacent silicon-oxygen tetrahedra in the silicate network structure. This promotes the breakage of more bridging oxygens, generating new non-bridging oxygens, thus producing a large amount of non-bridging oxygen. The non-bridging oxygen dipoles can react with moisture (such as environmental water vapor adsorbed on the surface of the raw materials, crystal water bound between glaze components, or equilibrium moisture introduced during the process) to generate hydroxyl groups, increasing the number of hydroxyl groups on the surface of the hydrophilic self-cleaning glaze layer.

[0030] In addition, the glaze formula also includes aluminum phosphate (AlPO4), the surface of which is composed of Al... 3+ and PO4 3- The aluminum phosphate is composed of alternating ions. When aluminum phosphate comes into direct contact with liquid water, water molecules (H2O) attack and adsorb onto the unstable Al-OP bonds on the surface of the aluminum phosphate, causing the Al-OP bonds to break (i.e., hydrolyze), as follows:

[0031] Al-OP + H2O → Al-OH + HO-P;

[0032] The aforementioned hydrolysis reaction generates two hydrophilic groups, aluminum hydroxyl (Al-OH) and phosphorus hydroxyl (P-OH), on the surface of the hydrophilic self-cleaning glaze layer, thereby increasing the number of hydroxyl groups on the surface of the hydrophilic self-cleaning glaze layer. It should be noted that, as shown in the above reaction process, the generation of hydroxyl groups by aluminum phosphate is based on the incomplete hydrolysis of its surface atoms to generate polar aluminum hydroxyl (Al-OH) and phosphorus hydroxyl (P-OH). Therefore, the generation of hydroxyl groups by aluminum phosphate is dynamic and self-generating, and the degree and rate of dynamic hydroxyl generation depend on environmental conditions. The more humid the environment, the faster and more complete the hydrolysis reaction, and the stronger and faster the dynamic hydroxyl generation performance. The longer the exposure to a humid environment, the higher the degree of surface hydrolysis and the greater the number of hydroxyl groups generated. The higher the ambient temperature, the faster the hydrolysis reaction rate.

[0033] In addition, the raw materials for hydrophilic self-cleaning glazes also include zeolite and diatomaceous earth. The silicon (Si) and aluminum (Al) atoms in the zeolite framework combine with water molecules in the air to form silanol groups (Si-OH) and aluminumol groups (Al-OH), which also helps to increase the number of hydroxyl groups on the surface of the hydrophilic self-cleaning glaze layer. The main chemical component of diatomaceous earth is amorphous silicon dioxide (SiO2·nH2O). Its large inner and outer surfaces are rich in silanol groups, which also helps to increase the number of hydroxyl groups on the surface of the hydrophilic self-cleaning glaze layer.

[0034] In summary, this technical solution, through the synergistic effect of the aforementioned multiple aspects, enriches the surface of the hydrophilic self-cleaning glaze layer obtained by calcination with hydroxyl groups, strengthens the hydrogen bond adsorption capacity between the hydrophilic self-cleaning glaze layer and water molecules, improves the hydrophilicity of the surface of the hydrophilic self-cleaning glaze layer, and makes it easier for water to spread on the glaze surface and form a uniform water film, thereby removing and cleaning dirt from the surface of the tile, thus improving the hydrophilic self-cleaning performance.

[0035] Secondly, diatomaceous earth is a siliceous sedimentary rock with large pores and a huge specific surface area composed of micron-sized pores. Zeolite is a crystalline aluminosilicate mineral with regular, uniform nanoscale pores and channels within its crystal structure. Simultaneously, this technical solution introduces fluxes such as borax to control the timing and viscosity of the liquid phase. This liquid phase, without completely dissolving the diatomaceous earth and zeolite particles and preventing the complete collapse of their pore structures, firmly bonds and "anchors" the diatomaceous earth and zeolite within the glaze layer, allowing the diatomaceous earth to retain some of its inherent micron-sized pores and the zeolite to retain some of its inherent nanoscale pores. Together, they construct a highly efficient three-dimensional hydrophilic network: diatomaceous earth, with its large pore size and huge specific surface area, acts as a "high-speed waterway" and "reservoir," rapidly capturing and temporarily storing large amounts of water through capillary action; subsequently, this water is transported to the surrounding zeolite region, where the zeolite utilizes the strong adsorption properties of its nanopores and the ion exchange capacity of its surface cations (such as Na+ in zeolite). + and Ca 2+ (Through ion exchange, it can interact strongly with water molecules), achieving precise capture and powerful locking of water molecules. This process forms a continuous mechanism from physical water storage to chemical adsorption, which together significantly enhances the hygroscopic, spreading, and permeable capabilities of the glaze, thus endowing it with excellent hydrophilic self-cleaning properties.

[0036] It should be noted that the mechanism by which borax prevents the complete collapse of the pore structure of diatomaceous earth and zeolite is as follows: As a low-temperature flux, the introduction of borax into the glaze enables the glaze to form a large amount of low-viscosity liquid phase earlier during the calcination process. The liquid phase can uniformly encapsulate and support the pore structure of the two porous materials, diatomaceous earth and zeolite. Through the liquid phase sintering mechanism, a protective matrix is ​​established between the skeletons of diatomaceous earth and zeolite, thereby effectively delaying the pore collapse caused by the shrinkage of the skeleton of diatomaceous earth and zeolite during the heating process. This creates key conditions for maintaining the stability of the two porous materials, diatomaceous earth and zeolite particles, in the glaze layer.

[0037] Furthermore, after sintering, the crystalline framework structure of zeolite and diatomaceous earth is partially retained, resulting in a large number of hydrophilic active sites originating from their internal pores (zeolite contributes ion-exchangeable cations and silanol groups, while diatomaceous earth primarily provides abundant surface silanol groups). Due to the enormous specific surface area of ​​zeolite (up to hundreds of square meters per gram) and diatomaceous earth, these active sites are densely exposed on the glaze surface, and the number of active sites far exceeds that of traditional vitreous glazes. This abundance of active sites significantly enhances the hydrophilic self-cleaning properties of the glaze layer.

[0038] In summary, this technical solution, through the aforementioned multiple effects, endows the hydrophilic self-cleaning glaze layer obtained by calcining the hydrophilic self-cleaning glaze with hydrophilic self-cleaning properties, making it easier to remove dirt even if it adheres to the surface of the glaze layer. Furthermore, compared to hydrophilic self-cleaning coatings, the aging resistance of the hydrophilic self-cleaning glaze layer is significantly improved. Simultaneously, the silanol groups themselves possess extremely high strength and stability; even during the high-temperature firing process of the glaze, these hydroxyl groups remain in large quantities on the sintered glaze surface, providing permanent chemical hydrophilicity to the glaze surface. This greatly enhances the aging resistance of the hydrophilic self-cleaning glaze layer, overcoming the technical defect of poor aging resistance in existing hydrophilic self-cleaning coatings, which leads to poor time-limited hydrophilic self-cleaning properties. Moreover, the hydrophilic self-cleaning glaze layer is directly formed by calcining the hydrophilic self-cleaning glaze, resulting in extremely high adhesion to the ceramic tile. This overcomes the technical defect of limited adhesion between existing hydrophilic self-cleaning coatings and ceramic tiles, leading to poor time-limited hydrophilic self-cleaning properties. The synergy of these factors contributes to achieving durable and superior hydrophilic self-cleaning properties in the tiles. Furthermore, this technical solution eliminates the need for additional hydrophilic self-cleaning coatings on the tile surface, thus saving production costs and improving production efficiency.

[0039] Secondly, quartz, along with some incompletely melted diatomaceous earth and zeolite particles, serve as a "skeleton" material within the glaze layer. When the glaze melts at high temperatures, these high-refractive-resistance, high-hardness skeleton solid particles do not completely dissolve in the glass melt but are instead dispersed and encapsulated within the final glaze glass matrix. These residual hard particles constitute a reinforcing phase at the microscopic level. When the glaze surface is subjected to mechanical friction or scratches, these hard particles effectively hinder and resist the penetration and ploughing action of abrasives, similar to the particle reinforcement mechanism in composite materials, thereby significantly improving the hardness and wear resistance of the glaze surface. Simultaneously, the introduction of aluminum phosphate not only strengthens the glass network structure by forming high-strength aluminum phosphate crystals or solid solutions but also optimizes the high-temperature rheological properties of the glaze, promoting a denser glaze layer structure, thus synergistically improving the overall hardness and wear resistance of the glaze layer.

[0040] Finally, due to the presence of calcium hydroxyphosphate (Ca) in nano-bovine bone ash... 10 Phosphate ions in (PO4)6(OH)2 can undergo limited hydrolysis with water to generate hydrolysis products such as hydrogen phosphate or dihydrogen phosphate. The hydroxyl groups in these hydrolysis products migrate to the surface of the hydrophilic self-cleaning glaze layer at high temperatures and are directionally enriched through chemical bonding or hydrogen bonding with surface defects, thus significantly increasing the number of hydroxyl groups on the glaze surface and improving its hydrophilic self-cleaning properties. Therefore, existing technologies include adding nano-sized bovine bone ash to the hydrophilic self-cleaning glaze formulation to increase its hydrophilic self-cleaning properties. However, during the calcination of the hydrophilic self-cleaning glaze, some of the bone ash will dissolve at high temperatures, and the remaining hydroxyapatite crystals in the bone ash will precipitate during high-temperature calcination. Hydroxyapatite Ca 10 The refractive index of (PO4)6(OH)2 ranges from 1.647 to 1.651, significantly higher than the average refractive index of traditional silicate matrix glass (approximately 1.55). When hydroxyapatite is dispersed in the glaze layer in the form of microcrystals or particles, the difference in refractive index between it and the surrounding glass phase causes light scattering at the interface. This scattering effect is similar to the mechanism of opacifiers, leading to a tendency for the glaze surface to become opaque. Therefore, the thickness of the hydrophilic self-cleaning glaze must be strictly controlled within a thin layer of 0.05–0.1 mm to prevent the glaze surface from becoming opaque.

[0041] As mentioned earlier, this technical solution completely abandons the physical path of relying on bovine bone ash to generate hydrophilicity. Instead, it uses raw materials such as zeolite, diatomaceous earth, and aluminum phosphate, which are capable of generating hydrophilic properties, to construct hydrophilic self-cleaning properties. This allows the hydrophilic self-cleaning glaze to maintain high transparency regardless of the glaze thickness. The specific principle is as follows: Based on the selection of raw materials, this technical solution ensures that the glass phase obtained after calcining the remaining raw materials (excluding zeolite, diatomaceous earth, and aluminum phosphate) has high transparency. At the same time, zeolite, diatomaceous earth, and aluminum phosphate do not precipitate microcrystals with an opacifying effect during the calcination process. This eliminates the technical problem of having to limit the glaze thickness due to the precipitation of microcrystals with an opacifying effect from hydrophilic raw materials. This allows the transparency of the hydrophilic self-cleaning glaze layer obtained by calcination to be close to that of conventional glazes, thus helping to ensure high transparency.

[0042] To further clarify, the quartz has a mesh size of 3000 to 8000 mesh.

[0043] This technical solution limits the quartz particle size, which not only makes the quartz particles extremely fine, significantly increasing the specific surface area and surface energy, making it easier to distribute evenly in the glaze layer, but also avoids the problem of excessively fine quartz particles leading to an overly thick glaze, preventing air bubbles from escaping during the glazing process, and causing glaze cracking and peeling during drying, thus affecting the anti-fouling performance.

[0044] To further explain, the raw materials include the following by weight percentage: zeolite 30%, quartz 20%, calcite 15%, strontium carbonate 6%, barium carbonate 5%, diatomite 8%, kaolin 7%, borax 5%, and aluminum phosphate 4%.

[0045] This technical solution limits the amount of each raw material added to the hydrophilic self-cleaning glaze, which helps to ensure that the performance of the hydrophilic self-cleaning glaze reaches its optimal level.

[0046] A method for preparing a hydrophilic self-cleaning ceramic tile, using the aforementioned hydrophilic self-cleaning glaze, includes the following steps:

[0047] A. After mixing zeolite, quartz, calcite, strontium carbonate, barium carbonate, diatomaceous earth, kaolin, borax and aluminum phosphate evenly, add sodium methyl cellulose, sodium hexametaphosphate and water, ball mill, and sieve to obtain hydrophilic self-cleaning glaze.

[0048] B. Apply the hydrophilic self-cleaning glaze to the surface of the body, dry and fire to obtain hydrophilic self-cleaning ceramic tiles.

[0049] This technical solution also proposes a method for preparing hydrophilic self-cleaning ceramic tiles. The method is simple and easy to operate, ensuring that the resulting hydrophilic self-cleaning tiles achieve excellent and long-lasting hydrophilic self-cleaning properties while reducing production costs. Furthermore, it also helps to ensure high transparency, high hardness, and high wear resistance. It should be noted that the body in this solution is made from conventional ceramic blanks that have been pressed and dried; further description of the ceramic blanks is not provided here.

[0050] To further explain, in step A, the specific gravity of the hydrophilic self-cleaning glaze is 1.25 to 1.45.

[0051] When the specific gravity of the hydrophilic self-cleaning glaze is too high, the glaze becomes too thick, resulting in poor fluidity and uneven application, easily leading to defects such as glaze streaks. Furthermore, an excessively high specific gravity can also obstruct the escape of gases and moisture generated during firing, causing the glaze layer to crack easily. Conversely, if the specific gravity is too low, the glaze becomes too fluid, easily flowing during application, also resulting in uneven application and glaze streaks. Additionally, an excessively low specific gravity leads to excessive moisture in the glaze, potentially causing brick cracking during firing. Therefore, this technical solution limits the specific gravity of the hydrophilic self-cleaning glaze to 1.25–1.45, which helps ensure the uniformity of the hydrophilic self-cleaning effect and the quality of the glaze surface in the resulting tiles.

[0052] It should be noted that glaze streaks refer to areas where the glaze layer is thicker, while it is thinner or absent in other areas.

[0053] To further explain, in step A, the hydrophilic self-cleaning glaze, calculated by mass percentage, leaves a residue of 0.2-0.4% after passing through a 325-mesh sieve.

[0054] This technical solution limits the fineness of the hydrophilic self-cleaning glaze, ensuring that the raw materials in the glaze are evenly dispersed, thereby guaranteeing the product's performance.

[0055] To further explain, in step A, the amount of water added, calculated by mass percentage, is 33-50% of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium carboxymethyl cellulose added is 0.4-0.6% of the dry material of the hydrophilic self-cleaning glaze, and the amount of sodium hexametaphosphate added is 0.4-0.8% of the dry material of the hydrophilic self-cleaning glaze.

[0056] By limiting the amount of water added to 33-50% of the dry material of the hydrophilic self-cleaning glaze, the water content in the hydrophilic self-cleaning glaze is relatively high, which is conducive to the uniform dispersion of quartz, zeolite, diatomite and aluminum phosphate in the hydrophilic self-cleaning glaze, thereby helping to ensure the performance of the hydrophilic self-cleaning glaze.

[0057] Preferably, the amount of sodium carboxymethyl cellulose added is 0.4 to 0.6% of the dry material of the hydrophilic self-cleaning glaze, and the amount of sodium hexametaphosphate added is 0.4 to 0.8% of the dry material of the hydrophilic self-cleaning glaze. After adding the above additives to the mixture, the mixture is ball-milled for 12 hours and then sieved to obtain the hydrophilic self-cleaning glaze.

[0058] To further explain, in step B, the thickness of the hydrophilic self-cleaning glaze is 0.15–0.3 mm.

[0059] If the glaze thickness of the hydrophilic self-cleaning glaze is too thin, it will easily lead to glaze defects such as leakage into the body, which will affect the uniformity, hardness, and wear resistance of the hydrophilic self-cleaning property. If the glaze thickness is too thick, it will result in excessively high production costs. Therefore, this technical solution limits the glaze thickness of the hydrophilic self-cleaning glaze to 0.15–0.3 mm, which helps to ensure the performance of the hydrophilic self-cleaning ceramic tile while reducing costs.

[0060] A hydrophilic self-cleaning ceramic tile is prepared using the above-mentioned method for preparing hydrophilic self-cleaning ceramic tiles. The static contact angle of the hydrophilic self-cleaning ceramic tile without soaking in boiling water is ≤5°, and the static contact angle after soaking in boiling water for 30 days is ≤10°. The Mohs hardness is 7 and the wear resistance is ≥4.

[0061] A hydrophilic self-cleaning ceramic tile prepared by the above-mentioned method has a static contact angle ≤5° without being soaked in boiling water, and a static contact angle ≤10° after being soaked in boiling water for 30 days. It has a Mohs hardness of 7 and an abrasion resistance ≥4. This design allows for excellent and long-lasting hydrophilic self-cleaning properties while reducing production costs, and also helps ensure high transparency, high hardness, and high abrasion resistance. It should be noted that the abrasion resistance ≥4 here refers to an abrasion resistance ≥4 (2100 revolutions).

[0062] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0063] Static contact angle before immersion: The static contact angle of the ceramic tile before immersion in boiling water was tested according to the test method of GB / T 30447-2013 "Method for Measurement of Contact Angle of Nanofilm".

[0064] Static contact angle after soaking: The static contact angle of the ceramic tile after soaking in boiling water for 30 days was tested according to the test method of GB / T 30447-2013 "Method for Measurement of Contact Angle of Nanofilm".

[0065] Abrasion resistance: The abrasion resistance of the glaze surface of the product was tested using the test method of GB / T3810.7-2016 Test Methods for Ceramic Tiles Part 7: Determination of Abrasion Resistance of Glazed Tiles Surface.

[0066] Mohs hardness: The Mohs hardness of the brick surface was tested according to the European standard EN15771:2010.

[0067] Example 1

[0068] A. According to the mass percentage, 30% zeolite, 20% quartz (4000 mesh), 15% calcite, 6% strontium carbonate, 5% barium carbonate, 8% diatomaceous earth, 7% kaolin, 5% borax, and 4% aluminum phosphate are mixed evenly. Then, sodium methyl cellulose, sodium hexametaphosphate, and water are added and ball-milled. The mixture is then sieved to obtain a hydrophilic self-cleaning glaze. The specific gravity of the hydrophilic self-cleaning glaze is 1.3. According to the mass percentage, the residue after passing through a 325 mesh sieve is 0.2%. According to the mass percentage, the amount of water added is 45% of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium carboxymethyl cellulose added is 0.5% of the dry material of the hydrophilic self-cleaning glaze, and the amount of sodium hexametaphosphate added is 0.6% of the dry material of the hydrophilic self-cleaning glaze.

[0069] B. Apply the hydrophilic self-cleaning glaze to the surface of the body, dry and fire to obtain hydrophilic self-cleaning ceramic tile; the glaze thickness of the hydrophilic self-cleaning glaze is 0.2mm.

[0070] Example 2

[0071] A. According to the mass percentage, 35% zeolite, 18% 3000-mesh quartz, 11% calcite, 4% strontium carbonate, 7% barium carbonate, 6% diatomaceous earth, 5% kaolin, 7% borax, and 7% aluminum phosphate are mixed evenly, then sodium methyl cellulose, sodium hexametaphosphate, and water are added and ball-milled. The mixture is then sieved to obtain a hydrophilic self-cleaning glaze. The specific gravity of the hydrophilic self-cleaning glaze is 1.25. According to the mass percentage, the residue after passing through a 325-mesh sieve is 0.3%. According to the mass percentage, the amount of water added is 35% of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium carboxymethyl cellulose added is 0.4% of the dry material of the hydrophilic self-cleaning glaze, and the amount of sodium hexametaphosphate added is 0.8% of the dry material of the hydrophilic self-cleaning glaze.

[0072] B. Apply the hydrophilic self-cleaning glaze to the surface of the body, dry and fire to obtain hydrophilic self-cleaning ceramic tile; the glaze thickness of the hydrophilic self-cleaning glaze is 0.15mm.

[0073] Example 3

[0074] A. According to the mass percentage, 25% zeolite, 23% 8000-mesh quartz, 16% calcite, 8% strontium carbonate, 9% barium carbonate, 6% diatomaceous earth, 6% kaolin, 4% borax, and 3% aluminum phosphate are mixed evenly, then sodium methyl cellulose, sodium hexametaphosphate, and water are added and ball-milled. The mixture is then sieved to obtain a hydrophilic self-cleaning glaze. The specific gravity of the hydrophilic self-cleaning glaze is 1.45. According to the mass percentage, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, and the residue is 0.4%. According to the mass percentage, the amount of water added is 50% of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium carboxymethyl cellulose added is 0.6% of the dry material of the hydrophilic self-cleaning glaze, and the amount of sodium hexametaphosphate added is 0.4% of the dry material of the hydrophilic self-cleaning glaze.

[0075] B. Apply the hydrophilic self-cleaning glaze to the surface of the body, dry and fire to obtain hydrophilic self-cleaning ceramic tile; the glaze thickness of the hydrophilic self-cleaning glaze is 0.3mm.

[0076] Comparative Example 1

[0077] The preparation method and raw materials of Comparative Example 1 are the same as those of Example 1, except that bovine bone ash is used in Comparative Example 1 instead of zeolite, diatomaceous earth, and aluminum phosphate. That is, in Comparative Example 1, the hydrophilic self-cleaning glaze, calculated by mass percentage, includes the following raw materials: 42% bovine bone ash, 20% quartz with a mesh size of 4000, 15% calcite, 6% strontium carbonate, 5% barium carbonate, 7% kaolin, and 5% borax.

[0078] Comparative Example 2

[0079] Comparative Example 2 uses the same preparation method and raw materials as Example 1, except that it uses an existing hydrophilic self-cleaning glaze containing bovine bone ash. Specifically, in Comparative Example 2, the hydrophilic self-cleaning glaze, by mass parts, comprises the following raw materials: 45 parts hydrophilic frit, 5 parts nano-anatase titanium dioxide, 25 parts quartz, 15 parts calcite, 6 parts nano-zinc oxide, and 4 parts nano-bovine bone ash; the hydrophilic frit, by mass parts, comprises the following raw materials: 16 parts calcite, 18 parts wollastonite, 42 parts kaolin, 17 parts alumina, and 7 parts quartz.

[0080] Comparative Example 3

[0081] Comparative Example 3 was prepared using the same method and raw materials as Example 1, except that zeolite was not added to the hydrophilic self-cleaning glaze of Comparative Example 3. Specifically, in Comparative Example 3, the hydrophilic self-cleaning glaze, by mass percentage, comprised the following raw materials: 28.7% quartz (4000 mesh), 21.4% calcite, 8.6% strontium carbonate, 7.1% barium carbonate, 11.4% diatomaceous earth, 10% kaolin, 7.1% borax, and 5.7% aluminum phosphate.

[0082] Comparative Example 4

[0083] Comparative Example 4 was prepared using the same method and raw materials as Example 1, except that diatomaceous earth was not added to the hydrophilic self-cleaning glaze of Comparative Example 4. Specifically, in Comparative Example 4, the hydrophilic self-cleaning glaze, by mass percentage, comprised the following raw materials: 32.7% zeolite, 21.7% quartz (4000 mesh), 16.3% calcite, 6.5% strontium carbonate, 5.4% barium carbonate, 7.6% kaolin, 5.4% borax, and 4.4% aluminum phosphate.

[0084] Comparative Example 5

[0085] Comparative Example 5 was prepared using the same method and raw materials as Example 1, except that aluminum phosphate was not added to the hydrophilic self-cleaning glaze of Comparative Example 5. Specifically, in Comparative Example 5, the hydrophilic self-cleaning glaze, by mass percentage, comprised the following raw materials: 31.3% zeolite, 20.8% quartz (4000 mesh), 15.6% calcite, 6.3% strontium carbonate, 5.2% barium carbonate, 8.3% diatomaceous earth, 7.3% kaolin, and 5.2% borax.

[0086] The performance of the hydrophilic self-cleaning ceramic tiles prepared in the examples and comparative examples was tested, and the results are shown in Table 1 below:

[0087] Table 1. Performance test results of different hydrophilic self-cleaning ceramic tiles in the examples and comparative examples.

[0088]

[0089] As shown in Table 1, the static contact angle of the ceramic tile obtained by this technical solution is ≤5° without being soaked in boiling water, and ≤10° after being soaked in boiling water for 30 days. The Mohs hardness is 7, and the abrasion resistance is ≥4 (2100 revolutions). This is beneficial for achieving excellent and long-lasting hydrophilic self-cleaning properties while reducing production costs, and also helps to ensure high transparency, high hardness and high abrasion resistance to meet actual use needs.

[0090] In both Comparative Example 1 and Comparative Example 2, the use of hydrophilic self-cleaning glazes containing bovine bone ash resulted in poor translucency of the tiles obtained at a glaze thickness of 0.2 mm. Furthermore, Comparative Example 1, lacking the addition of zeolite, diatomaceous earth, and aluminum phosphate, exhibited reduced wear resistance and hardness in its hydrophilic self-cleaning tiles.

[0091] The hydrophilic self-cleaning glaze of Comparative Example 3 did not contain zeolite, the hydrophilic self-cleaning glaze of Comparative Example 4 did not contain diatomaceous earth, and the hydrophilic self-cleaning glaze of Comparative Example 5 did not contain aluminum phosphate. As a result, the hydrophilic self-cleaning properties, wear resistance and hardness of the hydrophilic self-cleaning tiles obtained in Comparative Examples 3, 4 and 5 all decreased.

[0092] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A hydrophilic self-cleansing glaze, characterized by, The hydrophilic self-cleaning glaze comprises the following raw materials by mass percentage: zeolite 25-35%, quartz 15-25%, calcite 10-18%, strontium carbonate 4-8%, barium carbonate 3-9%, diatomite 6-10%, kaolin 5-7%, borax 3-7%, and aluminum phosphate 3-7%.

2. The hydrophilic self-cleaning glaze according to claim 1, characterized in that, The mesh number of the quartz is 3000-8000.

3. The hydrophilic self-cleaning glaze according to claim 1, wherein The hydrophilic self-cleaning glaze comprises the following raw materials by mass percentage: zeolite 30%, quartz 20%, calcite 15%, strontium carbonate 6%, barium carbonate 5%, diatomite 8%, kaolin 7%, borax 5%, and aluminum phosphate 4%.

4. A method for producing a hydrophilic self-cleaning ceramic tile, characterized by, The method for preparing the hydrophilic self-cleaning ceramic tile comprises the following steps: A. mixing zeolite, quartz, calcite, strontium carbonate, barium carbonate, diatomite, kaolin, borax, and aluminum phosphate uniformly, adding sodium methyl cellulose, sodium hexametaphosphate, and water, ball-milling, and sieving to obtain the hydrophilic self-cleaning glaze; B. applying the hydrophilic self-cleaning glaze to the surface of a green body, drying, and calcining to obtain the hydrophilic self-cleaning ceramic tile.

5. The method for preparing a hydrophilic self-cleaning ceramic tile according to claim 4, characterized in that, In step A, the specific gravity of the hydrophilic self-cleaning glaze is 1.25-1.

45.

6. The method for preparing a hydrophilic self-cleaning ceramic tile according to claim 4, characterized in that, In step A, the hydrophilic self-cleaning glaze is sieved through a 325-mesh screen, and the residue is 0.2-0.4% by mass percentage.

7. The method for preparing a hydrophilic self-cleaning ceramic tile according to claim 4, characterized in that, In step A, the amount of water added is 33-50% of the amount of dry hydrophilic self-cleaning glaze, the amount of sodium carboxymethyl cellulose added is 0.4-0.6% of the amount of dry hydrophilic self-cleaning glaze, and the amount of sodium hexametaphosphate added is 0.4-0.8% of the amount of dry hydrophilic self-cleaning glaze.

8. The method for preparing a hydrophilic self-cleaning ceramic tile according to claim 4, characterized in that, In step B, the glaze thickness of the hydrophilic self-cleaning glaze is 0.15-0.3 mm.

9. A hydrophilic self-cleaning tile, characterized by, The hydrophilic self-cleaning ceramic tile prepared by the method of any one of claims 4-8 has a static contact angle of ≤5° without soaking in boiling water, a static contact angle of ≤10° after soaking in boiling water for 30 days, a Mohs hardness of 7, and a wear resistance of ≥4.

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