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

Abstract

The application discloses a kind of hydrophilic self-cleaning glaze, according to mass percentage calculation, including hydrophilic frit 75~95% and kaolin 5~25%;According to mass percentage calculation, the hydrophilic frit includes boric acid 2~4%, lithium carbonate 5~9%, wollastonite 30~40%, calcined talc 9~16%, kaolin 10~20%, quartz 13~22% and alumina 8~12%.A kind of hydrophilic self-cleaning glaze is proposed in the present application, under the premise of reducing production cost, can realize excellent and lasting self-cleaning, solve the technical problems of poor self-cleaning timeliness in the prior art.

Description

Technical Field

[0001] This invention relates to the field of building ceramics technology, and in particular to a hydrophilic self-cleaning glaze, a hydrophilic self-cleaning antique brick, and a method for preparing the same. Background Technology

[0002] Antique-style bricks, as an artistic building material that blends classical aesthetics with modern craftsmanship, are highly favored by consumers for their unique antique glaze effect, rich color layers, and strong historical charm. They are widely used in home decoration, commercial venues, and cultural tourism scenic spots.

[0003] To ensure the antique effect of antique-style bricks, their surfaces are usually designed to be uneven. While this uneven surface helps increase their anti-slip properties, it also easily becomes a breeding ground for dirt and grime. This not only affects the aesthetics of the antique-style bricks and reduces their decorative effect, but also makes cleaning them time-consuming and laborious, requiring the use of cleaning agents to effectively remove dirt.

[0004] To overcome the aforementioned shortcomings, existing technologies typically apply a hydrophilic self-cleaning coating to the surface of antique-style bricks. This coating forms a hydrophilic self-cleaning layer, allowing water to spread rapidly upon contact with the surface (i.e., a small static contact angle between water and the coating) and form a uniform water film. This water film can penetrate the interface between dirt and the coating, weakening the adhesion of the dirt. Furthermore, under the influence of gravity, the continuously flowing water film can carry away and remove dirt from the surface of the antique-style bricks, achieving a self-cleaning effect. However, due to the poor aging resistance and limited adhesion of the hydrophilic self-cleaning coating to the brick surface, it is prone to peeling off, has an extremely limited lifespan, and poor self-cleaning durability, failing to meet practical usage requirements. Additionally, applying a hydrophilic self-cleaning coating to the surface of the antique-style brick substrate is not conducive to reducing production costs. Summary of the Invention

[0005] The purpose of this invention is to propose a hydrophilic self-cleaning glaze that can achieve excellent and long-lasting self-cleaning properties while reducing production costs, thus solving the technical problem of poor self-cleaning timeliness in the prior art.

[0006] The second objective of this invention is to provide a method for preparing hydrophilic self-cleaning antique-style bricks. The method is simple and easy to operate, ensuring that the resulting hydrophilic self-cleaning antique-style bricks not only have excellent and long-lasting self-cleaning properties, but also help reduce costs.

[0007] The third objective of this invention is to provide a hydrophilic self-cleaning antique brick prepared by the above-mentioned method for preparing hydrophilic self-cleaning antique bricks, which has excellent and long-lasting self-cleaning properties.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] A hydrophilic self-cleaning glaze, by weight percentage, comprises 75-95% hydrophilic frit and 5-25% kaolin;

[0010] The hydrophilic frit, calculated by mass percentage, comprises 2-4% boric acid, 5-9% lithium carbonate, 30-40% wollastonite, 9-16% calcined talc, 10-20% kaolin, 13-22% quartz, and 8-12% alumina.

[0011] Furthermore, calculated by mass ratio, the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc is 1:(4-7).

[0012] Furthermore, by mass percentage, the hydrophilic frit comprises 3% boric acid, 8% lithium carbonate, 35% wollastonite, 12% calcined talc, 15% kaolin, 17% quartz, and 10% alumina.

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

[0014] A. Boric acid, lithium carbonate, wollastonite, calcined talc, kaolin, quartz and alumina are mixed evenly according to the formula, calcined and then water-quenched to obtain a hydrophilic frit;

[0015] B. After mixing the kaolin and the hydrophilic frit from step A evenly according to the formula, add sodium carboxymethyl cellulose, sodium tripolyphosphate and water, ball mill, and sieve to obtain the hydrophilic self-cleaning glaze.

[0016] C. Apply the hydrophilic self-cleaning glaze from step B to the body with a textured surface, dry and fire to obtain hydrophilic self-cleaning antique bricks.

[0017] Further, in step A, the calcination curve of the hydrophilic frit is as follows: the temperature is increased from room temperature to 1530°C at a heating rate of 8-10°C / min, and then held for 35-45 min.

[0018] Furthermore, in step B, the specific gravity of the hydrophilic self-cleaning glaze is 1.82 to 1.9.

[0019] Furthermore, by mass percentage, the hydrophilic self-cleaning glaze has a residue of 0.2% to 0.4% when sieved through a 325-mesh screen.

[0020] Furthermore, in step C, the thickness of the hydrophilic self-cleaning glaze is 0.3–0.7 mm.

[0021] Furthermore, in step C, the calcination temperature is 1200–1220°C.

[0022] A hydrophilic self-cleaning antique-style brick is prepared using the above-mentioned method for preparing hydrophilic self-cleaning antique-style bricks.

[0023] The technical solution provided by this invention may include the following beneficial effects:

[0024] 1. In the early stage of firing, the hydrophilic frit formulation has already achieved phase separation, with boric acid and lithium carbonate forming the upper phase layer, and the second-gradient fluxing system (wollastonite and calcined talc) and high-temperature raw materials (kaolin, quartz, and alumina) forming the lower phase layer. When the temperature reaches the melting point of each raw material in the lower layer, the raw materials in the lower layer will gradually melt. At the same time, as the calcination temperature continues to rise, the raw materials in the upper and lower phase layers will gradually decompose, causing the hydrophilic frit to eventually form a phase-separated melt with boron oxide and lithium oxide as the upper phase layer and calcium oxide, magnesium oxide, alumina, and silicon oxide as the lower phase layer. When the hydrophilic frit, which is essentially a phase-separated melt, is added to the glaze formulation, the glaze is calcined to form a glaze layer with boron oxide and lithium oxide as the upper phase layer and calcium oxide, magnesium oxide, alumina, and silicon oxide as the lower phase layer.

[0025] 2. Compared to hydrophilic self-cleaning coatings, hydrophilic self-cleaning glazes offer significantly improved aging resistance, overcoming the technical shortcomings of existing technologies where poor aging resistance of hydrophilic self-cleaning coatings leads to poor self-cleaning performance over time. Furthermore, since the hydrophilic self-cleaning glaze is directly fired from hydrophilic self-cleaning glaze materials, its adhesion to antique-style tiles is extremely high, overcoming the limited adhesion between existing hydrophilic self-cleaning coatings and antique-style tile surfaces, resulting in poor self-cleaning performance over time. The combined effect of these factors contributes to achieving long-lasting and excellent self-cleaning properties in antique-style tiles. In addition, this technical solution eliminates the need for additional hydrophilic self-cleaning coatings on the surface of antique-style tiles, saving production costs and improving production efficiency.

[0026] 3. In addition to promoting phase separation of hydrophilic self-cleaning glaze during calcination, the introduction of boric acid also helps to inhibit crystallization between the two phase melts in the upper and lower phases of the hydrophilic self-cleaning glaze during calcination, preventing the liquid phase in the upper phase from being too low, which would lead to unstable hydrophilic properties of the hydrophilic self-cleaning glaze. Detailed Implementation

[0027] This technical solution provides a hydrophilic self-cleaning glaze, which, by mass percentage, comprises 75-95% hydrophilic frit and 5-25% kaolin.

[0028] The hydrophilic frit, calculated by mass percentage, comprises 2-4% boric acid, 5-9% lithium carbonate, 30-40% wollastonite, 9-16% calcined talc, 10-20% kaolin, 13-22% quartz, and 8-12% alumina.

[0029] Current technology typically involves coating the surface of antique-style bricks with a hydrophilic self-cleaning coating, creating a layer that makes it relatively easy to remove dirt even if it adheres to the surface. However, due to the poor aging resistance and limited adhesion of the hydrophilic self-cleaning coating to the brick surface, it is prone to peeling off, resulting in a very limited lifespan and poor durability, failing to meet practical usage requirements. Furthermore, additionally coating the antique-style brick substrate with a hydrophilic self-cleaning coating does not help reduce production costs.

[0030] To achieve long-lasting self-cleaning properties while reducing costs, this technical solution proposes a hydrophilic self-cleaning glaze, the raw materials of which include hydrophilic frit and kaolin. The hydrophilic frit uses boric acid, lithium carbonate, wollastonite, and calcined talc as fluxes. Boric acid has a melting point of approximately 577℃, lithium carbonate approximately 723℃, wollastonite approximately 1500℃, and calcined talc approximately 1400℃. This creates a first-gradient fluxing system composed of boric acid and lithium carbonate, and a second-gradient fluxing system composed of wollastonite and calcined talc, with a significant difference in melting temperature between the two gradient fluxing systems. Simultaneously, the melting temperatures of the first-gradient fluxing system and the high-temperature raw materials (i.e., solid-phase materials) in the hydrophilic frit formulation, such as kaolin, quartz, and alumina, differ significantly. Conversely, the melting temperatures of the second-gradient fluxing system and the high-temperature raw materials in the hydrophilic frit formulation differ less. This results in the first-gradient fluxing system melting first during the early firing stage, leading to a melt primarily composed of boric acid and lithium carbonate. As the firing temperature increases, the melt viscosity gradually decreases, and other raw materials that have not yet reached their melting points, such as the second-gradient fluxing system and the high-temperature raw materials, sink to the bottom. In other words, during the early firing stage, the hydrophilic frit formulation system has already achieved phase separation, with boric acid and lithium carbonate forming the upper phase layer, and the second-gradient fluxing system (wollastonite and calcined talc) and the high-temperature raw materials (kaolin, quartz, and alumina) forming the lower phase layer. When the temperature reaches the melting points of the raw materials in the lower layer, these materials will gradually melt as well. Simultaneously, as the calcination temperature continuously increases, the raw materials in the upper and lower phase-separated layers gradually decompose, causing the hydrophilic melt to ultimately form a phase-separated melt with boron oxide and lithium oxide as the upper phase-separated layer and calcium oxide, magnesium oxide, aluminum oxide, and silicon oxide as the lower phase-separated layer. When the hydrophilic melt, which is essentially a phase-separated melt, is added to the glaze formula, the glaze is calcined to form a glaze layer with boron oxide and lithium oxide as the upper phase-separated layer and calcium oxide, magnesium oxide, aluminum oxide, and silicon oxide as the lower phase-separated layer.

[0031] Furthermore, since the surface tension of lithium oxide is 450 × 10⁻⁶ -3 N / M, the surface tension of boron oxide is 80×10 - 3 N / M, while the surface tension of water is 73×10 -3The surface tension of the glaze layer, N / m, is far greater than that of water, making it essentially a hydrophilic self-cleaning glaze layer with extremely strong hydrophilic properties. This allows for easier removal of dirt even when it adheres to the surface. Furthermore, compared to hydrophilic self-cleaning coatings, the glaze layer exhibits significantly improved aging resistance, overcoming the technical shortcomings of existing technologies where poor aging resistance of hydrophilic self-cleaning coatings leads to poor self-cleaning performance over time. Additionally, since the hydrophilic self-cleaning glaze layer is directly fired from the hydrophilic self-cleaning glaze material, its adhesion to antique-style tiles is extremely high, overcoming the technical shortcomings of existing technologies where the adhesion between hydrophilic self-cleaning coatings and antique-style tiles is limited, resulting in poor self-cleaning performance over time. The combined effect of these factors contributes to achieving long-lasting and excellent self-cleaning properties in antique-style tiles. Moreover, this technical solution eliminates the need for additional hydrophilic self-cleaning coatings on the surface of antique-style tiles, saving production costs and improving production efficiency.

[0032] Furthermore, the introduction of boric acid in this technical solution not only promotes phase separation of the hydrophilic self-cleaning glaze during calcination, but also helps to inhibit crystallization between the two phase-separated melts in the upper and lower phase-separated layers during calcination, preventing the liquid phase in the upper phase-separated layer from becoming too low, which would lead to unstable hydrophilic properties of the hydrophilic self-cleaning glaze.

[0033] It should be further explained that existing technologies generally add potassium feldspar and sodium feldspar to hydrophilic frits. Potassium feldspar has a melting point of approximately 1150℃, and sodium feldspar has a melting point of approximately 1120℃. Adding potassium feldspar and sodium feldspar to the hydrophilic frit formulation significantly reduces the melting temperature difference between the first and second gradient fluxing systems, preventing phase separation. Furthermore, because potassium feldspar and sodium feldspar contain large amounts of alumina and silica, the high-temperature viscosity of the melt in the early stages does not decrease significantly, further hindering phase separation. In addition, the potassium oxide produced during potassium feldspar calcination and the sodium oxide produced during sodium feldspar calcination have surface tensions lower than that of water. Therefore, adding potassium feldspar and sodium feldspar to the formulation is detrimental to the self-cleaning properties of the glaze. Thus, hydrophilic frits containing potassium feldspar and sodium feldspar as fluxes cannot be added to this technical solution.

[0034] Furthermore, the kaolin, quartz, and alumina in the hydrophilic frit not only improve the hardness and wear resistance of the hydrophilic frit, but also, as all three are high-temperature raw materials, they help increase the temperature difference between the upper and lower layers of the hydrophilic frit, promoting phase separation in the early stages of firing. It should be noted that the kaolin in the hydrophilic self-cleaning glaze formulation of this technical solution mainly acts as a suspending agent to prevent the hydrophilic frit from settling and affecting its performance.

[0035] Furthermore, by mass percentage, the hydrophilic frit comprises 2–4% boric acid, 5–9% lithium carbonate, 30–40% wollastonite, 9–16% calcined talc, 10–20% kaolin, 13–22% quartz, and 8–12% alumina. That is, the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc is 1:(3–8). When the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc is greater than 1:3, the amount of liquid phase formed by boric acid and lithium carbonate in the melt during the early stage of calcination will be excessive, resulting in a strong fluxing effect that easily dissolves the solid raw materials that are difficult to melt in the early stage, making phase separation difficult. When the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc is less than 1:8, the amount of liquid phase formed by boric acid and lithium carbonate in the melt during the early stage of calcination will be insufficient. On the one hand, this makes it difficult for the second-gradient fluxing system and high-temperature raw materials to sink, resulting in difficulty in phase separation. On the other hand, it makes the upper liquid phase layer too thin, affecting the surface tension of the glaze and thus affecting its self-cleaning hydrophilic properties.

[0036] To further explain, the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc is 1:(4-7).

[0037] In a preferred embodiment of this technical solution, optimizing the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc is beneficial to promoting phase separation of the hydrophilic self-cleaning glaze in the early stage of calcination, thus ensuring the performance of the hydrophilic self-cleaning glaze.

[0038] To further explain, the hydrophilic frit, by mass percentage, comprises 3% boric acid, 8% lithium carbonate, 35% wollastonite, 12% calcined talc, 15% kaolin, 17% quartz, and 10% alumina.

[0039] In a preferred embodiment of this technical solution, by limiting the amount of each raw material added to the hydrophilic frit, it is beneficial to optimize the performance of the hydrophilic frit, thereby ensuring the performance of the hydrophilic self-cleaning glaze.

[0040] A method for preparing a hydrophilic self-cleaning glaze antique-style tile, using the aforementioned hydrophilic self-cleaning glaze, includes the following steps:

[0041] A. Boric acid, lithium carbonate, wollastonite, calcined talc, kaolin, quartz and alumina are mixed evenly according to the formula, calcined and then water-quenched to obtain a hydrophilic frit;

[0042] B. After mixing the kaolin and the hydrophilic frit from step A evenly according to the formula, add sodium carboxymethyl cellulose, sodium tripolyphosphate and water, ball mill, and sieve to obtain the hydrophilic self-cleaning glaze.

[0043] C. Apply the hydrophilic self-cleaning glaze from step B to the body with a textured surface, dry and fire to obtain hydrophilic self-cleaning antique bricks.

[0044] This technical solution also proposes a method for preparing hydrophilic self-cleaning glazed antique bricks. The steps are simple and easy to operate, ensuring that the obtained hydrophilic self-cleaning antique bricks not only have self-cleaning properties, but also help reduce costs.

[0045] Specifically, in step B, the amount of sodium carboxymethyl cellulose added is 0.2%, sodium tripolyphosphate is 0.3%, and water is 35-38%, calculated according to the mass percentage 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.

[0046] To further explain, in step A, the calcination curve of the hydrophilic frit is as follows: the temperature is increased from room temperature to 1530°C at a heating rate of 8-10°C / min, and then held for 35-45 minutes.

[0047] In a preferred embodiment of this technical solution, by optimizing the calcination curve of the hydrophilic frit, all raw materials in the hydrophilic frit formulation can be melted, which is beneficial to promote phase separation, ensure the performance of the hydrophilic frit, and make the hydrophilic self-cleaning glaze with added hydrophilic frit have a certain transparency after calcination, thus improving its permeability.

[0048] To further explain, in step B, the specific gravity of the hydrophilic self-cleaning glaze is 1.82 to 1.9.

[0049] When the specific gravity of a 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, making it prone to cracking during firing. It should be noted that glaze streaks refer to areas where the glaze layer is thicker than others, or even absent.

[0050] To further explain, in step B, the residue of the hydrophilic self-cleaning glaze after passing through a 325-mesh sieve is 0.2% to 0.4% by mass percentage.

[0051] In a preferred embodiment of this technical solution, by limiting the fineness of the hydrophilic self-cleaning glaze, the sieve residue of the hydrophilic self-cleaning glaze is made lower, which is beneficial to make the hydrophilic self-cleaning glaze have a fine uniformity, reduce the roughness of the glaze surface caused by uneven particles, and improve the self-cleaning performance.

[0052] To further explain, in step C, the thickness of the hydrophilic self-cleaning glaze is 0.3 to 0.7 mm.

[0053] In a preferred embodiment of this technical solution, by limiting the glaze thickness, it is beneficial for the melt, which is mainly composed of boric acid and lithium carbonate, to have a certain thickness in the early stage of calcination, so that the raw materials that have not yet reached the melting point have enough space to sink, thereby promoting phase separation and ensuring its performance.

[0054] To further explain, in step C, the calcination temperature is 1200–1220°C.

[0055] In a preferred embodiment of this technical solution, by limiting the glaze firing temperature to 1200-1220℃, which is consistent with the firing temperature of existing antique brick products, the product performance is ensured while also making it easier to achieve industrial production, reducing the large deviations between the experimental and industrialization stages.

[0056] A hydrophilic self-cleaning antique-style brick is prepared using the above-mentioned method for preparing hydrophilic self-cleaning antique-style bricks.

[0057] A hydrophilic self-cleaning antique brick prepared by the above-mentioned method has excellent and long-lasting self-cleaning properties.

[0058] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0059] Performance testing:

[0060] Static contact angle before soaking: The static contact angle of the hydrophilic self-cleaning antique brick before soaking 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 <15°, it is qualified.

[0061] Static contact angle after soaking: The static contact angle of hydrophilic self-cleaning antique bricks after soaking in boiling water for 30 days is tested according to the test method of "GB / T 30447-2013 Nanofilm Contact Angle Measurement Method". If the contact angle is <25°, it is qualified.

[0062] Anti-slip performance: Anti-slip performance was tested according to DIN 51130:2014 Anti-slip Standard.

[0063] Mohs hardness: The Mohs hardness of hydrophilic self-cleaning antique bricks is tested using a Mohs hardness tester.

[0064] Example 1

[0065] A. According to the mass percentage, 3% boric acid, 8% lithium carbonate, 35% wollastonite, 12% calcined talc, 15% kaolin, 17% quartz and 10% alumina are mixed evenly, calcined and then water-quenched to obtain a hydrophilic frit; wherein, the calcination curve of the hydrophilic frit is: heated from room temperature to 1530℃ at a heating rate of 8-10℃ / min and held at that temperature for 40min;

[0066] B. According to the mass percentage, 20% of kaolin and 80% of the hydrophilic frit from step A are mixed evenly, and then sodium carboxymethyl cellulose, sodium tripolyphosphate and water are added and ball-milled. After sieving, a hydrophilic self-cleaning glaze with a specific gravity of 1.82 is obtained. Among them, according to the mass percentage, the residue of the hydrophilic self-cleaning glaze passing through a 325-mesh sieve is 0.2%. According to the mass percentage of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium carboxymethyl cellulose added is 0.2%, the amount of sodium tripolyphosphate added is 0.3%, and the amount of water added is 35%.

[0067] C. Apply the hydrophilic self-cleaning glaze from step B to a body with a textured surface, dry it, and fire it at a temperature of 1200-1220℃ to obtain a hydrophilic self-cleaning antique brick; wherein the thickness of the hydrophilic self-cleaning glaze is 0.5mm.

[0068] Example 2

[0069] A. According to the mass percentage, 2% boric acid, 9% lithium carbonate, 30% wollastonite, 16% calcined talc, 20% kaolin, 15% quartz and 8% alumina are mixed evenly, calcined and then water-quenched to obtain a hydrophilic frit; wherein, the calcination curve of the hydrophilic frit is: heated from room temperature to 1530℃ at a heating rate of 8-10℃ / min and held at that temperature for 35min;

[0070] B. According to the mass percentage, 10% of kaolin and 90% of the hydrophilic frit from step A are mixed evenly, and then sodium carboxymethyl cellulose, sodium tripolyphosphate and water are added and ball-milled. After sieving, a hydrophilic self-cleaning glaze with a specific gravity of 1.85 is obtained. Among them, according to the mass percentage, the residue of the hydrophilic self-cleaning glaze passing through a 325-mesh sieve is 0.3%. According to the mass percentage of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium carboxymethyl cellulose added is 0.2%, the amount of sodium tripolyphosphate added is 0.3%, and the amount of water added is 38%.

[0071] C. Apply the hydrophilic self-cleaning glaze from step B to a body with a textured surface, dry it, and fire it at a temperature of 1200-1220℃ to obtain a hydrophilic self-cleaning antique brick; wherein the thickness of the hydrophilic self-cleaning glaze is 0.3mm.

[0072] Example 3

[0073] A. According to the mass percentage, 4% boric acid, 5% lithium carbonate, 40% wollastonite, 9% calcined talc, 17% kaolin, 13% quartz, and 12% alumina are mixed evenly, calcined, and then water-quenched to obtain a hydrophilic frit; wherein, the calcination curve of the hydrophilic frit is as follows: the temperature is raised from room temperature to 1530℃ at a heating rate of 8-10℃ / min, and then held for 45min;

[0074] B. According to the mass percentage, 10% of kaolin and 90% of the hydrophilic frit from step A are mixed evenly, and then sodium carboxymethyl cellulose, sodium tripolyphosphate and water are added and ball-milled. After sieving, a hydrophilic self-cleaning glaze with a specific gravity of 1.9 is obtained. Among them, according to the mass percentage, the residue of the hydrophilic self-cleaning glaze passing through a 325-mesh sieve is 0.4%. According to the mass percentage of the dry material of the hydrophilic self-cleaning glaze, the amount of sodium carboxymethyl cellulose added is 0.2%, the amount of sodium tripolyphosphate added is 0.3%, and the amount of water added is 35%.

[0075] C. Apply the hydrophilic self-cleaning glaze from step B to a body with a textured surface, dry it, and fire it at a temperature of 1200-1220℃ to obtain a hydrophilic self-cleaning antique brick; wherein the thickness of the hydrophilic self-cleaning glaze is 0.7mm.

[0076] Comparative Example 1

[0077] 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 of model SM-TM-QS3500 / 3200 from Shangmeng Technology Wuxi Co., Ltd.

[0078] Comparative Example 2

[0079] Comparative Example 2 uses the same preparation method and raw materials as Example 1, except that potassium feldspar and sodium feldspar are added to the hydrophilic frit formulation in Comparative Example 2. Specifically, in Comparative Example 1, the hydrophilic frit, by mass percentage, comprises 3% boric acid, 8% lithium carbonate, 5% potassium feldspar, 3% sodium feldspar, 30% wollastonite, 12% calcined talc, 12% kaolin, 17% quartz, and 10% alumina.

[0080] Comparative Example 3

[0081] The preparation method and raw materials of Comparative Example 3 are the same as those of Example 1. The difference is that in Comparative Example 3, the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc is 1:2.

[0082] Comparative Example 4

[0083] The preparation method and raw materials of Comparative Example 4 are the same as those of Example 1. The difference is that in Comparative Example 4, the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc is 1:9.

[0084] The hydrophilic self-cleaning antique bricks prepared by the methods of Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests, and the results are shown in Table 1 below:

[0085] Table 1. Performance test results of different hydrophilic self-cleaning antique bricks in the examples and comparative examples.

[0086]

[0087] As shown in Table 1, the static contact angle of the antique bricks obtained by this technical solution before soaking is 8-15°, and the static contact angle after soaking is 15-22°. They not only have excellent and long-lasting self-cleaning properties, but also good anti-slip properties and hardness. They combine decorative and practical functions, which is more conducive to meeting the needs of consumers.

[0088] In Comparative Example 1, a hydrophilic self-cleaning coating was applied to the surface of the antique brick substrate to obtain a hydrophilic self-cleaning antique brick. Although the obtained antique brick had a small static contact angle with water before soaking and had good self-cleaning properties, the poor aging resistance of the hydrophilic self-cleaning coating and its limited adhesion to the brick surface caused the hydrophilic self-cleaning antique brick in Comparative Example 1 to peel off after soaking. The hydrophilic self-cleaning durability was poor, and the static contact angle after soaking could not be measured.

[0089] In Comparative Example 2, the addition of potassium feldspar and sodium feldspar to the hydrophilic frit formulation not only made phase separation difficult, but also reduced the surface tension of the glaze layer obtained by calcining the hydrophilic self-cleaning glaze, which increased the static contact angle of the antique brick and reduced its self-cleaning properties.

[0090] In Comparative Example 3, the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc was too large, resulting in an excessive amount of liquid phase formed by boric acid and lithium carbonate in the melt during the early stage of calcination. This resulted in an overly strong fluxing effect, which easily melted the solid raw materials that were not easily melted in the early stage, making it difficult to separate the phases. Consequently, the static contact angle of the antique bricks increased, leading to a decrease in their self-cleaning properties.

[0091] In Comparative Example 4, the ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc was too small, resulting in an insufficient amount of liquid phase formed by boric acid and lithium carbonate in the melt during the early stage of calcination. On the one hand, this made it difficult for the second-gradient fluxing system and high-temperature raw materials to sink, leading to difficulties in phase separation; on the other hand, it resulted in an excessively thin liquid phase in the upper layer of the phase separation, affecting the surface tension of the glaze and thus its self-cleaning hydrophilic properties.

[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-cleaning glaze, characterized in that, After calcination, the hydrophilic self-cleaning glaze forms a glaze layer with boron oxide and lithium oxide as the upper phase and calcium oxide, magnesium oxide, aluminum oxide and silicon oxide as the lower phase. Calculated by mass percentage, it includes 75-95% hydrophilic frit and 5-25% kaolin; The hydrophilic frit, calculated by mass percentage, comprises 2-4% boric acid, 5-9% lithium carbonate, 30-40% wollastonite, 9-16% calcined talc, 10-20% kaolin, 13-22% quartz, and 8-12% alumina, and does not contain potassium feldspar or sodium feldspar.

2. The hydrophilic self-cleaning glaze according to claim 1, characterized in that, The ratio of the sum of the mass percentages of boric acid and lithium carbonate to the sum of the mass percentages of wollastonite and calcined talc is 1:(4-7).

3. The hydrophilic self-cleaning glaze according to claim 1, characterized in that, The hydrophilic frit, by mass percentage, comprises 3% boric acid, 8% lithium carbonate, 35% wollastonite, 12% calcined talc, 15% kaolin, 17% quartz, and 10% alumina.

4. A method for preparing hydrophilic self-cleaning antique-style bricks, characterized in that, Using the hydrophilic self-cleaning glaze as described in any one of claims 1 to 3 includes the following steps: A. Boric acid, lithium carbonate, wollastonite, calcined talc, kaolin, quartz and alumina are mixed evenly according to the formula, calcined and then water-quenched to obtain a hydrophilic frit; B. After mixing the kaolin and the hydrophilic frit from step A evenly according to the formula, add sodium carboxymethyl cellulose, sodium tripolyphosphate and water, ball mill, and sieve to obtain the hydrophilic self-cleaning glaze. C. Apply the hydrophilic self-cleaning glaze from step B to the body with a textured surface, dry and fire to obtain hydrophilic self-cleaning antique bricks.

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

6. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 4, characterized in that, In step B, the specific gravity of the hydrophilic self-cleaning glaze is 1.82 to 1.

9.

7. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 4, characterized in that, In step B, the hydrophilic self-cleaning glaze has a residue of 0.2-0.4% by mass when passing through a 325-mesh sieve.

8. The method for preparing a hydrophilic self-cleaning antique-style brick according to claim 4, characterized in that, In step C, the thickness of the hydrophilic self-cleaning glaze is 0.3 to 0.7 mm.

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

10. A hydrophilic self-cleaning antique-style brick, characterized in that, It is prepared using the method for preparing hydrophilic self-cleaning antique bricks according to any one of claims 4 to 9.

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