Hydrophilic self-cleaning glaze, hydrophilic self-cleaning antique brick and preparation method thereof

Abstract

The present invention relates to the field of architectural ceramics, and in particular to a hydrophilic self-cleaning glaze, a hydrophilic self-cleaning antique tile, and a preparation method thereof. The glaze comprises the following raw materials, calculated by mass percentage: 65-75% hydrophilic frit, 8-12% kaolin, and 15-25% albite. The hydrophilic frit comprises the following raw materials, calculated by mass percentage: 20-36% boron magnesium powder, 8-16% calcite, 8-12% calcined talc, 15-35% magnesium oxide, 3-5% zinc oxide, 18-24% aluminum oxide, and 5-7% titanium dioxide. The hydrophilic self-cleaning glaze proposed by the present invention achieves excellent and long-lasting hydrophilic self-cleaning properties while reducing production costs, resolving the technical problems of poor hydrophilic self-cleaning durability and high production costs in the prior art.

Description

Technical Field

[0001] The invention relates to the technical field of building ceramics, in particular to a hydrophilic self-cleaning glaze, a hydrophilic self-cleaning antique brick and a preparation method thereof. Background Art

[0002] Antique tiles, as an artistic building material that combines classical aesthetics with modern craftsmanship, are deeply favored by consumers for their unique antique glaze effect, rich color layers and strong historical charm. They are widely used in home decoration, commercial places, cultural and tourist attractions and other fields.

[0003] To ensure the antique effect of antique tiles, the surface of antique tiles is usually designed with unevenness. Although this uneven surface is beneficial for increasing the anti-slip performance, it is also easy to accumulate dust, oil stains and other dirt. Ordinary wiping is difficult to thoroughly clean. Long-term accumulation not only affects the appearance but also may breed bacteria. Traditional cleaning methods usually rely on chemical cleaners or high-pressure water guns, which are not only inefficient but may also cause wear and corrosion to the tile surface.

[0004] In order to overcome the above-mentioned defects, the existing technology usually coats the surface of the antique brick with a hydrophilic self-cleaning coating, so that a hydrophilic self-cleaning coating is formed on the surface of the antique brick, so that water can spread quickly when it contacts the coating surface (that is, 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 the dirt and the coating, thereby reducing the adhesion of the dirt. Under the action of gravity, the continuously flowing water film can carry away and remove the dirt on the surface of the antique brick, achieving the effect of hydrophilic self-cleaning. However, the above method has the following defects: (1) The hydrophilic self-cleaning coating has poor aging resistance and is prone to aging when exposed to ultraviolet rays, rain and temperature changes for a long time, resulting in the gradual failure of the hydrophilic self-cleaning function and poor hydrophilic self-cleaning durability; (2) The hydrophilic self-cleaning coating has limited bonding strength with the antique brick substrate and is prone to peeling off under frequent friction or temperature difference stress, which also reduces the durability of the hydrophilic self-cleaning; (3) The surface of existing antique bricks generally has no hydrophilic self-cleaning properties and needs to be coated with an additional layer of hydrophilic self-cleaning coating to make it have hydrophilic self-cleaning properties. However, the additional coating of the hydrophilic self-cleaning coating is likely to increase production costs, which is not conducive to large-scale promotion and application.

[0005] Therefore, how to achieve lasting self-cleaning properties while reducing production costs has become a technical problem that needs to be solved urgently. Summary of the Invention

[0006] The purpose of the present invention is to provide a hydrophilic self-cleaning glaze that achieves excellent and lasting hydrophilic self-cleaning properties while reducing production costs, thereby solving the technical problems of poor hydrophilic self-cleaning durability and high production costs in the prior art.

[0007] The second purpose of the present invention is to provide a preparation method of hydrophilic self-cleaning antique tiles. The preparation method is simple and easy to operate, ensuring that the obtained hydrophilic self-cleaning antique tiles not only have excellent and lasting self-cleaning properties, but also help reduce costs.

[0008] The third purpose of the present invention is to provide a hydrophilic self-cleaning antique tile prepared by the above-mentioned method for preparing hydrophilic self-cleaning antique tiles. The hydrophilic self-cleaning antique tile has a static contact angle of 5 to 10° before being soaked in boiling water, and a static contact angle of 13 to 18° after being soaked in boiling water for 30 days, and has excellent, uniform and long-lasting self-cleaning performance.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] A hydrophilic self-cleaning glaze, calculated by weight percentage, comprises the following raw materials: 65-75% hydrophilic frit, 8-12% kaolin, and 15-25% albite;

[0011] Calculated by mass percentage, the hydrophilic frit includes the following raw materials: 20-36% boron magnesium powder, 8-16% calcite, 8-12% calcined talc, 15-35% magnesium oxide, 3-5% zinc oxide, 18-24% aluminum oxide and 5-7% titanium dioxide.

[0012] Furthermore, calculated by mass percentage, the hydrophilic frit includes the following raw materials: 25% boron magnesium powder, 10% calcite, 10% calcined talc, 25% magnesium oxide, 4% zinc oxide, 20% aluminum oxide and 6% titanium dioxide.

[0013] Furthermore, the following raw materials are included, calculated by mass percentage: 70% hydrophilic frit, 10% kaolin and 20% albite.

[0014] A method for preparing a hydrophilic self-cleaning antique tile, using the above-mentioned hydrophilic self-cleaning glaze, comprises the following steps:

[0015] A. Mixing boron magnesium powder, calcite, calcined talc, magnesium oxide, zinc oxide, aluminum oxide and titanium dioxide uniformly according to the proportion, calcining and water quenching to obtain a hydrophilic frit;

[0016] B. After uniformly mixing kaolin, albite and hydrophilic frit according to the proportion, adding sodium methyl cellulose, sodium tripolyphosphate and water, ball milling, and sieving to obtain a hydrophilic self-cleaning glaze;

[0017] C. Applying a hydrophilic self-cleaning glaze to the surface of the green body with a concave-convex effect, drying and calcining to obtain a hydrophilic self-cleaning antique tile.

[0018] Furthermore, in step A, the calcination temperature curve of the hydrophilic frit is: heating from room temperature to 1530° C. at a heating rate of 8-10° C. / min, and then keeping the temperature for 35-45 minutes.

[0019] Furthermore, in step B, the specific gravity of the hydrophilic self-cleaning glaze is 1.25 to 1.45.

[0020] Furthermore, in step B, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, and the residue is 0.2-0.4% calculated by mass percentage.

[0021] Furthermore, in step C, the glazing thickness of the hydrophilic self-cleaning glaze is 0.05 to 0.1 mm.

[0022] Furthermore, in step C, the calcination temperature is 1200-1220°C.

[0023] A hydrophilic self-cleaning antique tile is prepared using the above-mentioned method for preparing the hydrophilic self-cleaning antique tile. The hydrophilic self-cleaning antique tile has a static contact angle of 5-10° before being soaked in boiling water, and a static contact angle of 13-18° after being soaked in boiling water for 30 days.

[0024] The technical solution provided by the present invention can have the following beneficial effects:

[0025] 1. After calcining, the hydrophilic frit forms a hydrophilic melt mainly composed of calcium oxide, magnesium oxide, silicon dioxide, zinc oxide, aluminum oxide and titanium dioxide. At the same time, the kaolin and albite in the hydrophilic self-cleaning glaze formula are calcined and decomposed at high temperature to produce silicon dioxide and aluminum oxide. When the above hydrophilic melt is added to the hydrophilic self-cleaning glaze formula, combined with the silicon dioxide and aluminum oxide produced by the kaolin and albite in the hydrophilic self-cleaning glaze formula calcined and decomposed at high temperature, the hydrophilic self-cleaning glaze is calcined to form a hydrophilic self-cleaning glaze layer mainly composed of calcium oxide, magnesium oxide, silicon dioxide, zinc oxide, aluminum oxide and titanium dioxide. Among them, the surface tension of calcium oxide is 470×10 -3 N / M, the surface tension of magnesium oxide is 545×10 -3 N / M, the surface tension of silica is 290×10 -3 N / M, the surface tension of zinc oxide is 500×10 -3 N / M, the surface tension of aluminum oxide is 380×10 -3 N / M, the surface tension of titanium dioxide is 400×10 -3 N / m, while the surface tension of water is 73×10 -3 N / m, which makes the surface tension (i.e. surface energy) of the hydrophilic self-cleaning glaze layer much greater than the surface tension of water, giving the hydrophilic self-cleaning glaze layer a higher surface energy, so that the surface of the hydrophilic self-cleaning glaze layer has extremely strong hydrophilic self-cleaning properties.

[0026] 2. Based on the formula design of this technical solution, the content of alkaline oxides (such as sodium oxide, calcium oxide and magnesium oxide) in this technical solution is relatively high, which can provide a large amount of free oxygen ions, thereby increasing the O / Si ratio in the system. Due to the increase in the O / Si ratio, small anion units with high charge density are enriched in the interior of the self-cleaning melt, and the surface of the self-cleaning melt is mainly covered by low-polarity alkaline oxides. Due to the strong ionicity and low dipole moment of the metal-oxygen bond, the interactions between low-polarity alkaline oxides are weak and disordered. According to the principles of surface thermodynamics, such disordered structures require higher energy to maintain stability, resulting in a significant increase in the surface tension of the self-cleaning melt. More energy is required to maintain stability, thereby increasing the surface tension of the self-cleaning melt, further ensuring the high surface energy of the hydrophilic self-cleaning glaze layer, and giving it extremely strong hydrophilic self-cleaning properties. DETAILED DESCRIPTION

[0027] The present technical solution provides a hydrophilic self-cleaning glaze, which comprises the following raw materials, calculated by weight percentage: 65-75% hydrophilic frit, 8-12% kaolin, and 15-25% albite;

[0028] Calculated by mass percentage, the hydrophilic frit includes the following raw materials: 20-36% boron magnesium powder, 8-16% calcite, 8-12% calcined talc, 15-35% magnesium oxide, 3-5% zinc oxide, 18-24% aluminum oxide and 5-7% titanium dioxide.

[0029] In order to achieve long-lasting self-cleaning properties while reducing costs, the present technical solution proposes a hydrophilic self-cleaning glaze, the raw materials of which include hydrophilic frit, kaolin and albite, and the frit of the hydrophilic frit includes boron magnesium powder, calcite, calcite, magnesium oxide, zinc oxide, aluminum oxide and titanium dioxide.

[0030] First, during the calcination of the hydrophilic frit, the raw materials in the frit undergo a series of decomposition and conversion reactions: calcite (primarily calcium carbonate) decomposes upon heating to produce calcium oxide; calcined talc and magnesium borate powder both decompose upon heating to produce magnesium oxide. Simultaneously, calcined talc also decomposes to produce silicon dioxide, which, combined with the magnesium oxide, zinc oxide, aluminum oxide, and titanium dioxide contained in the hydrophilic frit, forms a hydrophilic melt primarily composed of calcium oxide, magnesium oxide, silicon dioxide, zinc oxide, aluminum oxide, and titanium dioxide.

[0031] At the same time, the kaolin and albite in the hydrophilic self-cleaning glaze formula are calcined and decomposed at high temperatures to produce silicon dioxide and aluminum oxide. When the hydrophilic melt is added to the hydrophilic self-cleaning glaze formula, combined with the silicon dioxide and aluminum oxide produced by the kaolin and albite in the hydrophilic self-cleaning glaze formula calcined at high temperatures, the hydrophilic self-cleaning glaze is calcined to form a hydrophilic self-cleaning glaze layer mainly composed of calcium oxide, magnesium oxide, silicon dioxide, zinc oxide, aluminum oxide and titanium dioxide.

[0032] Furthermore, the surface tension of calcium oxide is 470×10 -3 N / M, the surface tension of magnesium oxide is 545×10 -3 N / M, the surface tension of silica is 290×10 -3 N / M, the surface tension of zinc oxide is 500×10 -3 N / M, the surface tension of aluminum oxide is 380×10 -3 N / M, the surface tension of titanium dioxide is 400×10 -3 N / m, while the surface tension of water is 73×10 -3 N / m, making the surface tension (i.e., surface energy) of the hydrophilic self-cleaning glaze layer much greater than the surface tension of water, giving the hydrophilic self-cleaning glaze layer a higher surface energy, thereby making the surface of the hydrophilic self-cleaning glaze layer have extremely strong hydrophilic self-cleaning properties. It should be noted that for the description of the surface properties of liquids and solids, liquids are generally described by surface tension, while solids are generally described by surface energy. Therefore, in the subsequent description, the surface tension of the glaze layer is described by surface energy.

[0033] Secondly, the calcium oxide, aluminum oxide and silicon dioxide introduced by the calcination of the raw materials in the formula system of this technical solution react to form anorthite crystals (CaAl2Si2O8), and magnesium oxide reacts with aluminum oxide and silicon dioxide to form cordierite crystals (Mg2Al2Si2O 18), aluminum oxide and silicon dioxide can react to form mullite (3Al2O3·2SiO2). During the precipitation process, due to anisotropic growth and the existence of dislocation defects, some of the crystals exist in the form of microcrystals. The precipitated microcrystals are usually irregular in shape, such as polyhedrons, needles and flakes. When the above irregularly shaped microcrystals precipitate from the glass phase (matrix) of the glaze layer, a micro-nano rough structure will be formed on the glaze surface. The micro-nano rough structure can improve the hydrophilic self-cleaning properties of the glaze layer through the following mechanisms: (1) The micro-nano rough structure greatly increases the microscopic roughness of the surface of the self-cleaning glaze layer and increases its actual specific surface area. The increase in specific surface area exposes more surface atoms or molecules. The above surface atoms or molecules are in an unstable state with high energy due to the presence of unsaturated chemical bonds (such as dangling bonds). The accumulation of high-energy surface atoms can effectively increase the surface energy of the glaze surface; (2) The micro-nano rough structure increases the local curvature of the surface of the self-cleaning glaze layer and increases the chemical potential of the surface atoms, which is beneficial to improving the surface energy of the self-cleaning glaze layer. It should be noted that only micro-nano roughness, representing a microscopic structure, can affect the surface energy of the glaze layer. The millimeter-scale or even centimeter-scale bumps and grooves on the surface of antique tiles are macroscopic structures that only affect the mechanical anti-slip properties of the tile and do not alter the chemical properties of the glaze layer. Furthermore, while millimeter-scale or even centimeter-scale bumps and grooves may contain ordinary microscopic roughness, these microscopic roughness structures generally do not reach the critical scale of "significantly increased local curvature," resulting in a limited contribution of these ordinary microscopic roughness to the surface energy. The millimeter-scale bumps and grooves primarily affect the mechanical anti-slip properties of the tile.

[0034] Furthermore, based on the design of the raw material content in the hydrophilic self-cleaning glaze formula and the hydrophilic frit formula in this case, the overall silica content in the hydrophilic self-cleaning glaze formula of this technical solution is controlled at 20-32%, which is much lower than the silica content in conventional antique tile glazes (>50%). The above design significantly reduces the silica content of the formula system, and the silicon content is also significantly reduced. At the same time, based on the formula design of this technical solution, the content of alkaline oxides (such as sodium oxide, calcium oxide, and magnesium oxide) in this technical solution is relatively high, which can provide a large amount of free oxygen ions, thereby increasing the O / Si ratio in the system. It should be noted that, in one embodiment, the chemical composition of the conventional antique tile glaze, calculated by mass percentage, includes 55-65% silicon dioxide, 8-12% aluminum oxide, 10-15% calcium oxide, 3-6% potassium oxide, 2-4% sodium oxide, 1-3% magnesium oxide, 1-3% zinc oxide, 0.6-2.5% barium oxide and 0.5-2% iron oxide, and the rest is loss on ignition.

[0035] Furthermore, acidic oxides such as silica react with alkaline oxides (such as calcium oxide and magnesium oxide) to form a silicate network (i.e., a glassy phase). The high O / Si ratio breaks the bridging oxygens between the silicon-oxygen tetrahedra within the silicate network, generating negatively charged non-bridging oxygens (Si-O-), which decompose the silicate network into small anionic units. Due to their small size, these small anionic units possess a high charge density, resulting in the formation of high-charge-density small anionic units. These high-charge-density anionic units interact strongly with cations within the self-cleaning melt (i.e., the hydrophilic, self-cleaning glaze layer), forming a stable bulk structure and hindering their migration from the melt to the surface. Furthermore, the high-charge-density small anionic units have a high polarity. Migration to the surface of the self-cleaning melt introduces additional electric field energy, which tends to be in a state of lowest energy. Therefore, in order to reduce the energy of the self-cleaning melt surface, the system will preferentially repel small anion units with high charge density and push them into the interior of the self-cleaning melt, making it difficult for small anion groups to migrate to the surface of the self-cleaning melt.

[0036] In summary, due to the increase in the O / Si ratio, small anionic units with high charge density are enriched in the interior of the self-cleaning melt, and the surface of the self-cleaning melt is mainly covered by low-polarity alkaline oxides. Due to the strong ionicity and low dipole moment of the metal-oxygen bond, the interactions between low-polarity alkaline oxides are weak and the arrangement is disordered. According to the principles of surface thermodynamics, this disordered structure requires higher energy to maintain stability, resulting in a significant increase in the surface tension of the self-cleaning melt. More energy is required to maintain stability, thereby increasing the surface tension of the self-cleaning melt, further ensuring the high surface energy of the hydrophilic self-cleaning glaze layer, and giving it extremely strong hydrophilic self-cleaning properties.

[0037] Therefore, based on the above-mentioned multiple effects, the present technical solution makes the hydrophilic self-cleaning glaze layer formed by calcining the hydrophilic self-cleaning glaze have extremely strong hydrophilic self-cleaning properties. Even if dirt adheres to the surface of the hydrophilic self-cleaning glaze layer, the dirt is relatively easy to remove. In addition, compared with the hydrophilic self-cleaning coating, the aging resistance of the hydrophilic self-cleaning glaze layer is greatly improved, which is conducive to overcoming the technical defects of the prior art that the hydrophilic self-cleaning coating has poor aging resistance and poor self-cleaning timeliness. Furthermore, since the hydrophilic self-cleaning glaze layer is directly calcined by the hydrophilic self-cleaning glaze, its bonding strength with the antique brick is extremely high, which is conducive to overcoming the technical defects of the prior art that the hydrophilic self-cleaning coating has limited bonding strength with the brick surface of the antique brick, resulting in poor self-cleaning timeliness. The mutual coordination of the above-mentioned multiple factors is conducive to achieving long-lasting self-cleaning properties for the antique brick, and the self-cleaning properties are excellent. In addition, the present technical solution does not require additional coating of the hydrophilic self-cleaning coating on the surface of the antique brick, which is conducive to saving production costs and improving production efficiency.

[0038] Thirdly, the technical solution must add boron magnesium powder and titanium dioxide. The reason is that boron magnesium powder can decompose to form boron trioxide under high-temperature calcination. Boron trioxide and titanium dioxide are both acidic oxides. They can replace part of the silicon dioxide and react with alkaline oxides such as sodium oxide, calcium oxide and magnesium oxide to form a glass phase, ensuring that the amount of glass phase in the system is sufficient. If boron magnesium powder and titanium dioxide are not added, the content of silicon dioxide in the formula system of the technical solution is much lower than the content of silicon dioxide in conventional antique tile glazes, and the amount of glass phase generated in the formula system will be reduced. The reduction of the glass phase not only leaves more pores inside the hydrophilic self-cleaning glaze layer, resulting in reduced mechanical strength and easy glaze cracking (crazing) or peeling, but also causes defects such as orange peel effect (unevenness) or pinholes on the glaze surface, thereby affecting the quality of the glaze.

[0039] Furthermore, the present technical solution cannot completely replace boron magnesium powder and titanium dioxide with titanium dioxide for the following reasons: (1) If all boron magnesium powder and titanium dioxide are replaced with titanium dioxide, the initial melting point of the system will be too high due to the high melting point of titanium dioxide. In order to lower the initial melting point of the formulation system, more potassium oxide or sodium oxide needs to be introduced. However, compared with components such as calcium oxide, magnesium oxide, silicon dioxide, zinc oxide, aluminum oxide and titanium dioxide, the surface tension of potassium oxide and sodium oxide is relatively low, which will reduce the surface tension of the formulation system and affect the hydrophilic self-cleaning properties. (2) The color of titanium dioxide after melting is yellow or white. If all boron magnesium powder and titanium dioxide are replaced with titanium dioxide, the amount of titanium dioxide introduced into the formulation system will be large. Excessive melting of titanium dioxide will easily make the glaze surface appear yellow or white, affecting the transparency of the glaze surface. It should be noted that the initial melting point refers to the lowest temperature at which the glaze begins to melt.

[0040] Furthermore, this technical solution cannot use boron trioxide instead of boron magnesium powder because the melting point of boron trioxide is 450°C, while the melting point of boron magnesium powder is around 830°C, a significant difference between the two. Replacing the boron magnesium powder in this technical solution with boron trioxide would lower the initial melting point of the formulation, causing the formulation to melt prematurely during calcination. This would then interact with the walls of the quartz or corundum crucible, dissolving the crucible walls and introducing components that are not part of the formulation.

[0041] Finally, in this technical solution, the magnesium oxide in the hydrophilic frit cannot be replaced with calcined talc. The reason is that calcined talc can introduce a large amount of silica. If the magnesium oxide and calcined talc in the hydrophilic frit are both introduced in the form of calcined talc, a large amount of silica will be introduced into the formula system, causing the O / Si ratio in the formula system to decrease, thereby affecting the hydrophilic self-cleaning performance.

[0042] It should be noted that hydrophilic frit is a barren material and prone to sedimentation. Therefore, this technical solution incorporates kaolin into the hydrophilic self-cleaning glaze formulation, utilizing a kaolin suspending agent to prevent sedimentation and thus affect its performance. Furthermore, the kaolin and aluminum oxide in this technical solution's formulation enhance the hardness and wear resistance of the hydrophilic self-cleaning glaze, ensuring its functionality and practicality.

[0043] It should be further explained that the boron magnesium powder used in this solution can be purchased through commercial channels and has a relatively low market price, which can effectively control the preparation cost of the hydrophilic self-cleaning glaze.

[0044] It is further explained that, calculated by mass percentage, the hydrophilic frit includes the following raw materials: 25% boron magnesium powder, 10% calcite, 10% calcined talc, 25% magnesium oxide, 4% zinc oxide, 20% aluminum oxide and 6% titanium dioxide.

[0045] This technical solution helps to optimize the performance of the hydrophilic frit by limiting the addition amount of each raw material in the hydrophilic frit, thereby helping to ensure the performance of the hydrophilic self-cleaning glaze.

[0046] Further description, calculated by weight percentage, includes the following raw materials: 70% hydrophilic frit, 10% kaolin and 20% albite.

[0047] This technical solution helps to ensure that the performance of the hydrophilic self-cleaning glaze is optimal by limiting the addition amount of each raw material in the hydrophilic self-cleaning glaze.

[0048] A method for preparing a hydrophilic self-cleaning antique tile, using the above-mentioned hydrophilic self-cleaning glaze, comprises the following steps:

[0049] A. Mixing boron magnesium powder, calcite, calcined talc, magnesium oxide, zinc oxide, aluminum oxide and titanium dioxide uniformly according to the proportion, calcining and water quenching to obtain a hydrophilic frit;

[0050] B. After uniformly mixing kaolin, albite and hydrophilic frit according to the proportion, adding sodium methyl cellulose, sodium tripolyphosphate and water, ball milling, and sieving to obtain a hydrophilic self-cleaning glaze;

[0051] C. Applying a hydrophilic self-cleaning glaze to the surface of the green body with a concave-convex effect, drying and calcining to obtain a hydrophilic self-cleaning antique tile.

[0052] This technical solution also proposes a method for preparing hydrophilic self-cleaning antique tiles. The preparation method is simple and easy to operate, ensuring that the resulting hydrophilic self-cleaning antique tiles not only have excellent and long-lasting self-cleaning properties but also help reduce costs. It should be noted that the green body in this solution is made by pressing and drying conventional ceramic green bodies in the ceramic field, and the ceramic green bodies are not further described here.

[0053] Specifically, in step B, calculated by mass percentage, the amount of sodium carboxymethyl cellulose added is 0.2-0.4% of the amount of dry material added to the hydrophilic self-cleaning glaze, the amount of sodium tripolyphosphate added is 0.3-0.5% of the amount of dry material added to the hydrophilic self-cleaning glaze, and the amount of water added is 35-38% of the amount of dry material added to the hydrophilic self-cleaning glaze. After adding the above additives to the mixed material, ball milling is carried out for 12 hours, and then sieving to obtain the hydrophilic self-cleaning glaze.

[0054] Further, in step A, the calcination temperature curve of the hydrophilic frit is: heating from room temperature to 1530°C at a heating rate of 8-10°C / min, and then keeping the temperature for 35-45 minutes.

[0055] This technical solution optimizes the calcination temperature curve of the hydrophilic frit so that all raw materials in the hydrophilic frit formula can be melted, which not only helps to ensure the performance of the hydrophilic frit, but also makes the hydrophilic self-cleaning glaze with the addition of the hydrophilic frit have a certain transparency after calcination, thereby improving its permeability.

[0056] Further description, in step B, the specific gravity of the hydrophilic self-cleaning glaze is 1.25-1.45.

[0057] When the specific gravity of the hydrophilic self-cleaning glaze is too high, the glaze will be too thick and the fluidity will deteriorate, resulting in poor uniformity in the application of the hydrophilic self-cleaning glaze and the easy formation of defects such as glaze paths. In addition, the high specific gravity of the hydrophilic self-cleaning glaze will easily hinder the discharge of gases and water generated by the hydrophilic self-cleaning glaze during the calcination process, causing the glaze layer obtained by calcining the hydrophilic self-cleaning glaze to crack easily. When the specific gravity of the hydrophilic self-cleaning glaze is too low, the fluidity of the hydrophilic self-cleaning glaze is too good, and it is easy to flow during the glazing process, which also causes poor uniformity in the application of the hydrophilic self-cleaning glaze and the easy formation of defects such as glaze paths. In addition, the specific gravity of the hydrophilic self-cleaning glaze is too low, resulting in excessive water in the glaze, and the phenomenon of brick explosion is easy to occur during the calcination process. Therefore, the technical solution limits the specific gravity of the hydrophilic self-cleaning glaze to 1.25~1.45, which is conducive to ensuring the uniformity of the hydrophilic self-cleaning effect and the glaze quality of the antique tiles obtained.

[0058] It should be noted that glaze path refers to the glaze layer being thicker in some areas and thinner or missing in other areas.

[0059] Further, in step B, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, and the residue is 0.2-0.4% calculated by mass percentage.

[0060] This technical solution limits the fineness of the hydrophilic self-cleaning glaze, so that the raw materials in the hydrophilic self-cleaning glaze can be evenly dispersed, thereby ensuring the performance of the product.

[0061] Further description, in step C, the glazing thickness of the hydrophilic self-cleaning glaze is 0.05 to 0.1 mm.

[0062] If the glaze thickness of the hydrophilic self-cleaning glaze is too thin, it will easily lead to glaze defects such as leakage of the green body, which will not only easily affect the uniformity of the hydrophilic self-cleaning property, but also easily affect the appearance of the product. If the glaze thickness of the hydrophilic self-cleaning glaze is too thick, the hydrophilic self-cleaning glaze layer formed by the calcination of the hydrophilic self-cleaning glaze will easily shrink, similarly exposing the surface of the green body, which will not only easily affect the uniformity of the hydrophilic self-cleaning property, but also easily affect the appearance of the product. Therefore, this technical solution limits the glaze thickness of the hydrophilic self-cleaning glaze to 0.05-0.1mm, which is conducive to ensuring the uniformity of the hydrophilic self-cleaning property.

[0063] Further description, in step C, the calcination temperature is 1200-1220°C.

[0064] This technical solution limits the calcination temperature to 1200-1220°C, which is consistent with the firing temperature of existing antique brick products. While ensuring product performance, it is also easy to achieve the purpose of industrial production and avoid large deviations between the experimental stage and the industrial stage.

[0065] A hydrophilic self-cleaning antique tile is prepared using the above-mentioned method for preparing the hydrophilic self-cleaning antique tile. The hydrophilic self-cleaning antique tile has a static contact angle of 5-10° before being soaked in boiling water, and a static contact angle of 13-18° after being soaked in boiling water for 30 days.

[0066] A hydrophilic self-cleaning antique tile prepared by the above-mentioned preparation method has a static contact angle of 5-10° before being soaked in boiling water and a static contact angle of 13-18° after being soaked in boiling water for 30 days, and has excellent and long-lasting self-cleaning performance.

[0067] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0068] Performance testing:

[0069] Static contact angle before immersion: The static contact angle of the hydrophilic self-cleaning antique tile before immersion in boiling water is tested according to the test method of "GB / T 30447-2013 Nanofilm Contact Angle Measurement Method". If the static contact angle is ≤10°, it is qualified.

[0070] Static contact angle after immersion: According to the test method of "GB / T 30447-2013 Nanofilm Contact Angle Measurement Method", the static contact angle of the hydrophilic self-cleaning antique tile after soaking in boiling water for 30 days is tested. If the contact angle is ≤18°, it is qualified.

[0071] Anti-slip performance: Anti-slip performance is tested according to the DIN 51130:2014 anti-slip standard.

[0072] Mohs hardness: The Mohs hardness of the hydrophilic self-cleaning antique tiles was tested using a Mohs hardness tester.

[0073] Example 1

[0074] A. 25% boron magnesium powder, 10% calcite, 10% calcined talc, 25% magnesium oxide, 4% zinc oxide, 20% aluminum oxide, and 6% titanium dioxide were uniformly mixed according to mass percentage, calcined, and then water-quenched to obtain a hydrophilic frit; wherein the calcination temperature curve of the hydrophilic frit was as follows: heating from room temperature to 1530°C at a rate of 8°C / min, and then holding the temperature for 40 minutes;

[0075] B. Calculated by mass percentage, 70% of hydrophilic frit, 10% of kaolin, and 20% of albite are uniformly mixed, and sodium methyl cellulose, sodium tripolyphosphate, and water are added for ball milling, and the mixture is sieved to obtain a hydrophilic self-cleaning glaze; wherein, calculated by mass percentage, the amount of sodium carboxymethyl cellulose added is 0.2% of the amount of dry material added to the hydrophilic self-cleaning glaze, the amount of sodium tripolyphosphate added is 0.3% of the amount of dry material added to the hydrophilic self-cleaning glaze, and the amount of water added is 35% of the amount of dry material added to the hydrophilic self-cleaning glaze; the specific gravity of the hydrophilic self-cleaning glaze is 1.25; calculated by mass percentage, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, and the sieve residue is 0.3%;

[0076] C. Applying a hydrophilic self-cleaning glaze to the surface of the green body with a concave-convex effect, drying and calcining at a temperature of 1200° C. to obtain a hydrophilic self-cleaning antique tile; wherein the glazing thickness of the hydrophilic self-cleaning glaze is 0.08 mm.

[0077] Example 2

[0078] A. 30% boron magnesium powder, 14% calcite, 8% calcined talc, 20% magnesium oxide, 3% zinc oxide, 18% aluminum oxide, and 7% titanium dioxide were uniformly mixed according to mass percentage, calcined, and then water-quenched to obtain a hydrophilic frit; wherein the calcination temperature curve of the hydrophilic frit was as follows: heating from room temperature to 1530°C at a rate of 10°C / min, and then holding the temperature for 45 minutes;

[0079] B. Calculated by mass percentage, 65% of hydrophilic frit, 12% of kaolin, and 23% of albite are uniformly mixed, and then sodium methyl cellulose, sodium tripolyphosphate, and water are added for ball milling, and the mixture is sieved to obtain a hydrophilic self-cleaning glaze; wherein, calculated by mass percentage, the amount of sodium carboxymethyl cellulose added is 0.3% of the amount of dry material added to the hydrophilic self-cleaning glaze, the amount of sodium tripolyphosphate added is 0.4% of the amount of dry material added to the hydrophilic self-cleaning glaze, and the amount of water added is 37% of the amount of dry material added to the hydrophilic self-cleaning glaze; the specific gravity of the hydrophilic self-cleaning glaze is 1.45; calculated by mass percentage, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, and the sieve residue is 0.2%;

[0080] C. Applying a hydrophilic self-cleaning glaze to the surface of the green body with a concave-convex effect, drying and calcining at a temperature of 1220° C. to obtain a hydrophilic self-cleaning antique tile; wherein the glazing thickness of the hydrophilic self-cleaning glaze is 0.1 mm.

[0081] Example 3

[0082] A. 20% boron magnesium powder, 9% calcite, 12% calcined talc, 30% magnesium oxide, 3% zinc oxide, 21% aluminum oxide, and 5% titanium dioxide were uniformly mixed according to mass percentage, calcined, and then water-quenched to obtain a hydrophilic frit; wherein the calcination temperature curve of the hydrophilic frit was as follows: heating from room temperature to 1530°C at a rate of 10°C / min, and then holding the temperature for 45 minutes;

[0083] B. Calculated by mass percentage, 75% of hydrophilic frit, 10% of kaolin, and 15% of albite are uniformly mixed, and then sodium methyl cellulose, sodium tripolyphosphate, and water are added for ball milling, and the mixture is sieved to obtain a hydrophilic self-cleaning glaze; wherein, calculated by mass percentage, the amount of sodium carboxymethyl cellulose added is 0.2% of the amount of dry material added to the hydrophilic self-cleaning glaze, the amount of sodium tripolyphosphate added is 0.3% of the amount of dry material added to the hydrophilic self-cleaning glaze, and the amount of water added is 35% of the amount of dry material added to the hydrophilic self-cleaning glaze; the specific gravity of the hydrophilic self-cleaning glaze is 1.4; calculated by mass percentage, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, and the sieve residue is 0.3%;

[0084] C. Applying a hydrophilic self-cleaning glaze to the surface of the green body with a concave-convex effect, drying and calcining at a temperature of 1220° C. to obtain a hydrophilic self-cleaning antique tile; wherein the glazing thickness of the hydrophilic self-cleaning glaze is 0.08 mm.

[0085] Comparative Example 1

[0086] The hydrophilic self-cleaning antique brick in Comparative Example 1 includes an antique brick substrate and a hydrophilic self-cleaning coating distributed from bottom to top; the hydrophilic self-cleaning coating is obtained by curing a super hydrophilic coating model SM-TM-QS3500 / 3200 produced by Shangmeng Technology Wuxi Co., Ltd.

[0087] Comparative Example 2

[0088] Comparative Example 2 uses a conventional antique tile glaze from the prior art. Specifically, the hydrophilic self-cleaning antique tile in Comparative Example 2 is prepared by applying the conventional antique tile glaze to the surface of a body having a concave-convex effect, drying, and calcining at 1200°C to obtain the hydrophilic self-cleaning antique tile. The conventional antique tile glaze has a glaze thickness of 0.08 mm. The chemical composition of the conventional antique tile glaze, calculated by mass percentage, includes 55% silicon dioxide, 10% aluminum oxide, 15% calcium oxide, 4% potassium oxide, 3% sodium oxide, 2% magnesium oxide, 1% zinc oxide, 1% barium oxide, and 2% iron oxide, with the remainder being loss on ignition.

[0089] Comparative Example 3

[0090] The preparation method and raw materials of Comparative Example 3 are the same as those of Example 1, except that in Comparative Example 3, the magnesium oxide in the hydrophilic frit in Example 1 is replaced by calcined talc.

[0091] The performance tests of the hydrophilic self-cleaning antique tiles prepared in the embodiment and the comparative example were carried out respectively, and the results are shown in Table 1 below:

[0092] Table 1 Performance test results of different hydrophilic self-cleaning antique tiles in Examples and Comparative Examples

[0093]

[0094] It can be seen from the performance test results in Table 1 that the static contact angle of the antique tiles obtained by the present technical solution before immersion is 5-10°, and the static contact angle after immersion is 13-18°. It not only has excellent and long-lasting self-cleaning performance, but also has good anti-slip properties and hardness. It is both functional and practical, and is more conducive to meeting the usage needs of consumers.

[0095] In Comparative Example 1, a hydrophilic self-cleaning coating is provided on the surface of the antique brick substrate to obtain a hydrophilic self-cleaning antique brick. Although the obtained antique brick has a small static contact angle with water before immersion and has good self-cleaning properties, it is affected by the poor aging resistance of the hydrophilic self-cleaning coating and its limited bonding strength with the brick surface. As a result, after immersion, the hydrophilic self-cleaning coating of the hydrophilic self-cleaning antique brick in Comparative Example 1 falls off, the hydrophilic self-cleaning durability is poor, and the static contact angle after immersion cannot be measured.

[0096] In Comparative Example 2, conventional antique tile glaze according to the prior art is used. Since the O / Si ratio in the conventional antique tile glaze according to the prior art is low, the surface energy of the hydrophilic self-cleaning glaze layer is reduced, the static contact angle of the obtained antique tile is increased, and the hydrophilic self-cleaning property is reduced.

[0097] In Comparative Example 3, since the magnesium oxide in the hydrophilic frit was replaced with calcined talc, a large amount of silicon dioxide was introduced into the system, which reduced the O / Si ratio in the system, thereby reducing the surface energy of the hydrophilic self-cleaning glaze layer, increasing the static contact angle of the antique tile obtained, and reducing the hydrophilic self-cleaning property.

[0098] 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 hydrophilic self-cleaning glaze, characterized in that: Calculated by weight percentage, it is composed of the following raw materials: 65-75% of hydrophilic frit, 8-12% of kaolin and 15-25% of albite; Calculated by mass percentage, the hydrophilic frit is composed of the following raw materials: 20-36% boron magnesium powder, 8-16% calcite, 8-12% calcined talc, 15-35% magnesium oxide, 3-5% zinc oxide, 18-24% aluminum oxide and 5-7% titanium dioxide.

2. A hydrophilic self-cleaning glaze according to claim 1, characterized in that: Calculated by mass percentage, the hydrophilic frit is composed of the following raw materials: 25% boron magnesium powder, 10% calcite, 10% calcined talc, 25% magnesium oxide, 4% zinc oxide, 20% aluminum oxide and 6% titanium dioxide.

3. The hydrophilic self-cleaning glaze according to claim 1, characterized in that: Calculated by mass percentage, it is composed of the following raw materials: 70% hydrophilic frit, 10% kaolin and 20% albite.

4. A method for preparing hydrophilic self-cleaning antique tiles, characterized in that: Using the hydrophilic self-cleaning glaze according to any one of claims 1 to 3 comprises the following steps: A. Mixing boron magnesium powder, calcite, calcined talc, magnesium oxide, zinc oxide, aluminum oxide and titanium dioxide uniformly according to the proportion, calcining and water quenching to obtain a hydrophilic frit; B. After uniformly mixing kaolin, albite and hydrophilic frit according to the proportion, adding sodium methyl cellulose, sodium tripolyphosphate and water, ball milling, and sieving to obtain a hydrophilic self-cleaning glaze; C. Applying a hydrophilic self-cleaning glaze to the surface of the green body with a concave-convex effect, drying and calcining to obtain a hydrophilic self-cleaning antique tile.

5. The method for preparing a hydrophilic self-cleaning antique tile according to claim 4, characterized in that: In step A, the calcination temperature curve of the hydrophilic frit is: heating from room temperature to 1530° C. at a heating rate of 8-10° C. / min, and then keeping the temperature for 35-45 minutes.

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

45.

7. The method for preparing a hydrophilic self-cleaning antique tile according to claim 4, characterized in that: In step B, the hydrophilic self-cleaning glaze passes through a 325-mesh sieve, and the residue is 0.2-0.4% calculated by mass percentage.

8. The method for preparing a hydrophilic self-cleaning antique tile according to claim 4, characterized in that: In step C, the glazing thickness of the hydrophilic self-cleaning glaze is 0.05 to 0.1 mm.

9. The method for preparing a hydrophilic self-cleaning antique tile according to claim 4, characterized in that: In step C, the calcination temperature is 1200-1220°C.

10. A hydrophilic self-cleaning antique tile, characterized by: The hydrophilic self-cleaning antique brick is prepared by the preparation method of any one of claims 4 to 9. The static contact angle of the hydrophilic self-cleaning antique brick before being soaked in boiling water is 5 to 10 degrees, and the static contact angle after being soaked in boiling water for 30 days is 13 to 18 degrees.

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