Highly reflective thermal barrier ceramic glaze

Abstract

The application discloses a high-reflective heat-insulating ceramic glaze and relates to the technical field of ceramics. The high-reflective heat-insulating ceramic glaze is prepared from the following raw materials in percentage by mass: titanium melt block 30-50%, titanium sphene powder 10-30% and titanium white powder 4-7.5%. The high-reflective heat-insulating ceramic glaze can be fired to form a high-reflective heat-insulating ceramic glaze layer with a titanium sphene crystal mass content of 30-45%. In terms of particle quantity, 15-35% of the titanium sphene crystals in the high-reflective heat-insulating ceramic glaze layer have a particle size uniformly distributed in the range of 300-600 nm, 50-70% of the titanium sphene crystals have a particle size uniformly distributed in the range of 600-900 nm, 5-25% of the titanium sphene crystals have a particle size uniformly distributed in the range of 900-1200 nm, 2-10% of the titanium sphene crystals have a particle size uniformly distributed in the range of 1200-1500 nm, and 1-5% of the titanium sphene crystals have a particle size uniformly distributed in the range of 1500-2000 nm. The titanium sphene crystals are distributed in the range of 300-2500 nm of sunlight, can better reflect full-band sunlight, and thus achieve a good heat-insulating effect.

Description

Technical Field

[0001] This invention relates to the field of ceramic technology, and in particular to a high-reflectivity heat-insulating ceramic glaze. Background Technology

[0002] In summer, buildings are exposed to strong sunlight, resulting in high indoor temperatures and significant energy consumption for air conditioning. Applying solar-reflective insulating ceramic tiles to building roofs and exterior walls can effectively reduce the surface temperature of the building and the surrounding air, achieving passive cooling and thus reducing the power consumption of cooling equipment, achieving energy conservation and environmental protection. The reflective insulation performance of solar-reflective insulating ceramic tiles mainly depends on the reflection of sunlight by the glaze layer.

[0003] In existing technologies, many methods achieve high reflectivity of ceramic glazes to sunlight by forming titanium sphene crystals within the glaze layer, as illustrated in patent applications with publication numbers CN106830684A, CN111499202B, and CN111875414B. While patent application CN106830684A discloses a solar reflectance ratio, this data is calculated using a weighted average method, which cannot fully demonstrate high reflectivity across the entire spectrum of sunlight. Furthermore, it does not specify the content and particle size distribution of the titanium sphene crystals, parameters that are crucial for reflecting sunlight across the entire spectrum. In addition to these issues, this approach also suffers from a large glaze layer thickness, leading to significant manufacturing difficulties and high production costs.

[0004] While the patent application with publication number CN111499202B claims to have high reflectivity, its thermal reflectivity for sunlight with wavelengths greater than 600nm decreases significantly, which greatly reduces the heat insulation effect of the glaze. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a high-reflectivity heat-insulating ceramic glaze, which aims to improve the heat insulation performance of ceramic tiles against sunlight across the entire spectrum.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-reflectivity heat-insulating ceramic glaze, wherein the raw materials for preparing the high-reflectivity heat-insulating ceramic glaze, by mass percentage, include: 30%–50% titanium frit, 10%–30% titanium sphene powder, and 4%–7.5% titanium dioxide.

[0008] The high-reflectivity heat-insulating ceramic glaze, wherein the average particle size of the titanium sphene powder is 1-4 μm.

[0009] The high-reflectivity heat-insulating ceramic glaze, wherein, by mass percentage, the titanium frit contains 10% ≤ TiO2 ≤ 15% and Al2O3 ≤ 6%.

[0010] The high-reflectivity heat-insulating ceramic glaze, wherein the molar ratio of titanium to calcium in the raw materials for preparing the high-reflectivity heat-insulating ceramic glaze is 1:1 to 1:1.5.

[0011] The high-reflectivity heat-insulating ceramic glaze mentioned above is prepared from one or more of the following raw materials: quartz, sodium feldspar, potassium feldspar, alumina, calcite, kaolin, talc, dolomite, wollastonite, barium carbonate, strontium carbonate, and zinc oxide.

[0012] The high-reflectivity heat-insulating ceramic glaze, by mass percentage, comprises the following raw materials: 50% titanium frit, 10% titanium sphene powder, 4% titanium dioxide, 8% kaolin, 20% quartz, 5% calcite, and 3% talc; the chemical composition of the titanium frit comprises: 60% SiO2, 5% Al2O3, 17% CaO, 13.5% TiO2, 1% K2O, 2.5% Na2O, 0.8% MgO, and 0.2% Fe2O3.

[0013] The high-reflectivity heat-insulating ceramic glaze, by mass percentage, comprises the following raw materials: 40% titanium frit, 20% titanium sphene powder, 7.5% titanium dioxide, 6% kaolin, 12% quartz, 5% potassium feldspar, 8% dolomite, and 1.5% strontium carbonate; the chemical composition of the titanium frit comprises: 60.5% SiO2, 5.5% Al2O3, 18% CaO, 10% TiO2, 2.3% K2O, 3.1% Na2O, 0.4% MgO, and 0.2% Fe2O3.

[0014] The high-reflectivity heat-insulating ceramic glaze, by mass percentage, comprises the following raw materials: 30% titanium frit, 30% titanium sphene powder, 6% titanium dioxide, 6% kaolin, 10% quartz, 5% albite, 12% wollastonite, and 1% barium carbonate; the chemical composition of the titanium frit comprises: 60% SiO2, 6% Al2O3, 18% CaO, 10% TiO2, 2.3% K2O, 3.1% Na2O, 0.4% MgO, and 0.2% Fe2O3.

[0015] The high-reflectivity heat-insulating ceramic glaze, by mass percentage, comprises the following raw materials: 45% titanium frit, 15% titanium sphene powder, 5% titanium dioxide, 9% kaolin, 10% quartz, 10% calcite, 3% talc, 2% zinc oxide, and 1% alumina; the chemical composition of the titanium frit includes:

[0016] SiO2 58%, Al2O3 4%, CaO 19%, TiO2 15%, K2O 1.5%, Na2O 2%, MgO 0.3%,

[0017] Fe2O3 0.2%.

[0018] The high-reflectivity heat-insulating ceramic glaze is fired at a temperature of 1170℃~1230℃ and a firing cycle of 30~90 minutes.

[0019] Beneficial effects: The present invention provides a high reflectivity heat-insulating ceramic glaze, which includes a specific amount of titanium frit, titanium sphene powder and titanium dioxide. The high reflectivity heat-insulating ceramic glaze layer formed after firing contains a large number of titanium sphene crystals with a particle size distribution of 300-2000nm. Specifically, in this titanium sphene crystal, by particle count, 15%–35% of the titanium sphene crystals have a uniform particle size distribution of 300–600 nm, 50%–70% have a uniform particle size distribution of 600–900 nm, 5%–25% have a uniform particle size distribution of 900–1200 nm, 2%–10% have a uniform particle size distribution of 1200–1500 nm, and 1%–5% have a uniform particle size distribution of 1500–2000 nm. By containing a large number of titanium sphene crystals of specific particle sizes, the high-reflectivity heat-insulating ceramic glaze layer has high reflectivity for sunlight with wavelengths of 300–2500 nm.

[0020] The high-reflectivity heat-insulating ceramic glaze is also suitable for a one-time firing process, which is compatible with the current preparation process and firing regime of building ceramic bricks, resulting in high production efficiency and energy saving and environmental protection. Attached Figure Description

[0021] Figure 1 The XRD pattern is shown in Example 1.

[0022] Figure 2 This is a SEM image of Example 1;

[0023] Figure 3 This is a reflectance curve diagram for Example 1;

[0024] Figure 4 This is the SEM image of Comparative Example 1;

[0025] Figure 5 This is a reflectance curve for Comparative Example 1. Detailed Implementation

[0026] This invention provides a high-reflectivity heat-insulating ceramic glaze. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0027] The first aspect of this invention provides a high-reflectivity heat-insulating ceramic glaze layer, wherein the content of titanium sphene crystals in the high-reflectivity heat-insulating ceramic glaze layer is 30% to 45% by mass; wherein, by particle number, 15% to 35% of the titanium sphene crystals are uniformly distributed with a particle size of 300 to 600 nm, 50% to 70% of the titanium sphene crystals are uniformly distributed with a particle size of 600 to 900 nm, 5% to 25% of the titanium sphene crystals are uniformly distributed with a particle size of 900 to 1200 nm, 2% to 10% of the titanium sphene crystals are uniformly distributed with a particle size of 1200 to 1500 nm, and 1% to 5% of the titanium sphene crystals are uniformly distributed with a particle size of 1500 to 2000 nm. Based on the characteristics of solar energy distribution, over 99% of the total radiation energy has wavelengths between 0.15 and 4 μm, and the wavelength range of solar radiation observed on Earth is approximately 300–2500 nm. Ceramic glaze layers are composed of glassy and crystalline phases; sunlight reaching the glaze layer undergoes transmission, absorption, reflection, and scattering. Within the 300–2500 nm range, the glaze layer exhibits weak transmission and absorption of sunlight, but strong reflection and scattering, resulting in high reflectivity. When the particle size is comparable to the wavelength of solar radiation, Mie scattering occurs, resulting in a strong scattering effect. Mie scattering refers to the scattering phenomenon of particles with sizes close to or larger than the incident light wavelength. Therefore, although the titanium sphene crystals in the high-reflectivity heat-insulating ceramic glaze layer of this invention have a particle size distribution only within the 300–2000 nm range, they still exhibit high reflectivity across the entire wavelength range of sunlight from 300 to 2500 nm.

[0028] Rayleigh scattering occurs when the particle size is much smaller than the wavelength of the incident light. The intensity of Rayleigh scattering is inversely proportional to the fourth power of the wavelength of the incident light. Therefore, if the particle size distribution of the titanium sphene crystals in the glaze layer differs greatly from the wavelengths of the main solar radiation, its reflectivity in the visible and near-infrared regions will be much lower than its reflectivity in the mid- and far-infrared wavelength regions, making it unable to have high reflectivity for sunlight across the entire wavelength range.

[0029] At the same time, the content of titanium sphene crystals in the glaze and the thickness of the glaze also have a direct impact on the reflectivity.

[0030] The second aspect of this invention provides a high-reflectivity heat-insulating ceramic glaze. After firing, the high-reflectivity heat-insulating ceramic glaze forms the high-reflectivity heat-insulating ceramic glaze layer as described above. By mass percentage, the raw materials for preparing the high-reflectivity heat-insulating ceramic glaze include: 30%–50% titanium frit, 10%–30% titanium sphene powder, 4%–7.5% titanium dioxide, and the remainder being other raw materials. In the high-reflectivity heat-insulating ceramic glaze layer, titanium frit, titanium dioxide, and titanium sphene powder are all sources of Ti. During rapid firing, Ti, Si, Ca, and O elements in the glaze all participate in the reaction to generate titanium sphene crystals, and the reaction process differs depending on the source of Ti. Titanium frit is both a source of titanium and a major source of the eutectic. Titanium frit has a strong melting capacity at high temperatures, capable of melting most of the titanium dioxide and titanium sphene powder, while the unmelted portion can serve as crystal nuclei. After titanium dioxide and titanium sphene powder are melted, small particles of titanium sphene crystals precipitate out along with the original titanium components of the titanium frit. Some of the titanium sphene powder, after being melted, exists in the glaze layer as large titanium sphene crystal particles smaller than 2 μm. Preferably, the firing temperature of the high-reflectivity heat-insulating ceramic glaze is 1170℃~1230℃.

[0031] When the glaze formulation is unsuitable, titanium will exist in the form of rutile after firing (correspondingly reducing the content of titanite). Titanite is granular, while rutile is rod-shaped. Under the same TiO2 content and glaze thickness, the solar reflectance of a glaze dominated by titanite is higher than that of a glaze dominated by rutile. Therefore, when the glaze formulation is unsuitable, the resulting glaze will have low solar reflectance. Furthermore, glazes containing more rutile will also have a yellowish tint, affecting the visual appeal.

[0032] In the formulation of the high-reflectivity heat-insulating ceramic glaze of the present invention, the present invention takes advantage of the characteristic that titanium frit has a strong dissolving ability for crystals at high temperatures, uses titanium frit as the main titanium source, and introduces titanium sphene powder and titanium dioxide, so that the glaze obtains a large amount of titanium sphene crystals under rapid firing conditions, and the particle size of titanium sphene crystals is mainly between 300 and 2000 nm.

[0033] The gloss level of this high-reflectivity heat-insulating ceramic glaze is only 3° to 30° after firing, which effectively avoids light pollution caused by light reflection and meets the application requirements of ceramic tiles on roofs and exterior walls.

[0034] Specifically, in the preparation of high-reflectivity heat-insulating ceramic glaze, the other raw materials can be selected from clay materials, quartz, sodium feldspar, potassium feldspar, alumina, calcite, kaolin, talc, dolomite, wollastonite, barium carbonate, strontium carbonate, zinc oxide, and other materials.

[0035] Preferably, the average particle size of the titanium sphene powder is 1–4 μm. The particle size of the titanium sphene powder should not be too large or too small, otherwise the titanium sphene crystals formed after firing will be too large or too small.

[0036] Preferably, by mass percentage, the titanium fused block contains 10% ≤ TiO2 ≤ 15% and Al2O3 ≤ 6%. If the TiO2 content in the titanium fused block is too low, it will be unfavorable for the precipitation of a large amount of titanium sphene; if the Al2O3 content in the titanium fused block is too high, it will be unfavorable for the precipitation of large-particle titanium sphene.

[0037] Preferably, in the raw materials for preparing the reflective heat-insulating ceramic glaze, the molar ratio of titanium to calcium is 1:1 to 1:1.5.

[0038] A third aspect of the present invention provides a high-reflectivity heat-insulating ceramic brick, the high-reflectivity heat-insulating ceramic brick comprising a body layer, a base glaze layer and a high-reflectivity heat-insulating ceramic glaze layer as described above, arranged sequentially.

[0039] Preferably, the thickness of the body layer is 3-20 mm; the thickness of the base glaze layer is 0.1-0.2 mm; and the thickness of the high-reflectivity heat-insulating ceramic glaze layer is 0.15-0.4 mm.

[0040] A fourth aspect of the present invention provides a method for preparing ceramic tiles, the method being used to prepare the high-reflectivity heat-insulating ceramic tiles described above, comprising the following steps:

[0041] Apply a base glaze to the body layer so that a base glaze layer is formed after firing;

[0042] Apply the aforementioned high-reflectivity heat-insulating ceramic glaze onto the base glaze to form a high-reflectivity heat-insulating ceramic glaze layer after firing; specifically, colorants can be added to the high-reflectivity heat-insulating ceramic glaze or patterns can be printed on the surface of the high-reflectivity heat-insulating ceramic glaze according to process requirements.

[0043] The firing temperature is 1170℃~1230℃, and the firing cycle is 30~90 minutes.

[0044] Preferably, the chemical composition of the base glaze, by mass percentage, includes: 60%–70% SiO2, 20%–30% Al2O3, 3%–5% Na2O, 1%–3% K2O, 0.5%–1.5% CaO, 0.5%–1.5% MgO, and 1%–3% loss on ignition.

[0045] Example 1

[0046] A high-reflectivity heat-insulating ceramic brick, the preparation method of which includes the following steps:

[0047] S100. Apply a base glaze to the body layer so that a base glaze layer is formed after firing;

[0048] The chemical composition of the base glaze, by mass percentage, includes: SiO2 66%, Al2O3 23%, Na2O 4%, K2O 2.5%, CaO 1.5%, MgO 0.5%, and loss on ignition 2.5%.

[0049] S200. Apply the high-reflectivity heat-insulating ceramic glaze described below onto the base glaze to form a high-reflectivity heat-insulating ceramic glaze layer after firing;

[0050] The raw materials for preparing the high-reflectivity heat-insulating ceramic glaze, by mass percentage, include: 50% titanium frit, 10% titanium sphene powder, 4% titanium dioxide, 8% kaolin, 20% quartz, 5% calcite, and 3% talc.

[0051] Specifically, the average particle size of the titanium sphene powder is 2 μm;

[0052] The chemical composition of the titanium ingot, by mass percentage, includes: SiO2 60%, Al2O3 5%, CaO 17%, TiO2 13.5%, K2O 1%, Na2O 2.5%, MgO 0.8%, and Fe2O3 0.2%.

[0053] The final molar ratio of titanium to calcium in the high-reflectivity heat-insulating ceramic glaze is 1:1.37;

[0054] S300. Firing: The maximum firing temperature during firing is 1230℃, and the firing cycle is 30 minutes.

[0055] After firing, the thickness of each layer of the high-reflectivity heat-insulating ceramic tile was measured. The thickness of the body layer was 10 mm, the thickness of the base glaze layer was 0.15 mm, and the thickness of the high-reflectivity heat-insulating glaze layer was 0.28 mm.

[0056] Example 2

[0057] A high-reflectivity heat-insulating ceramic brick, the preparation method of which includes the following steps:

[0058] S100. Apply a base glaze to the body layer so that a base glaze layer is formed after firing;

[0059] The chemical composition of the base glaze, by mass percentage, includes: SiO2 62%, Al2O3 30%, Na2O 5%, K2O 1%, CaO 0.5%, MgO 0.5%, and loss on ignition 1%.

[0060] S200. Apply the high-reflectivity heat-insulating ceramic glaze described above onto the base glaze to form a high-reflectivity heat-insulating ceramic glaze layer after firing;

[0061] The raw materials for preparing the high-reflectivity heat-insulating ceramic glaze, by mass percentage, include: 40% titanium frit, 20% titanium sphene powder, 7.5% titanium dioxide, 6% kaolin, 12% quartz, 5% potassium feldspar, 8% dolomite, and 1.5% strontium carbonate.

[0062] Specifically, the average particle size of the titanium sphene powder is 3 μm;

[0063] The chemical composition of the titanium ingot, by mass percentage, includes: SiO2 60.5%, Al2O3 5.5%, CaO 18%, TiO2 10%, K2O 2.3%, Na2O 3.1%, MgO 0.4%, and Fe2O3 0.2%.

[0064] The final molar ratio of titanium to calcium in the high-reflectivity heat-insulating ceramic glaze is 1:1.12;

[0065] S300. Firing: The maximum firing temperature during firing is 1170℃, and the firing cycle is 90 minutes.

[0066] After firing, the thickness of each layer of the high-reflectivity heat-insulating ceramic tile was measured. The thickness of the body layer was 20 mm, the thickness of the base glaze layer was 0.13 mm, and the thickness of the high-reflectivity heat-insulating glaze layer was 0.4 mm.

[0067] Example 3

[0068] A high-reflectivity heat-insulating ceramic brick, the preparation method of which includes the following steps:

[0069] S100. Apply a base glaze to the body layer so that a base glaze layer is formed after firing;

[0070] The chemical composition of the base glaze, by mass percentage, includes: SiO2 61.5%, Al2O3 28.5%, Na2O 4.5%, K2O 1.5%, CaO 1%, MgO 1.5%, and loss on ignition 1.5%.

[0071] S200. Apply the high-reflectivity heat-insulating ceramic glaze described above onto the base glaze to form a high-reflectivity heat-insulating ceramic glaze layer after firing;

[0072] The raw materials for preparing the high-reflectivity heat-insulating ceramic glaze, by mass percentage, include: 30% titanium frit, 30% titanium sphene powder, 6% titanium dioxide, 6% kaolin, 10% quartz, 5% albite, 12% wollastonite, and 1% barium carbonate.

[0073] Specifically, the average particle size of the titanium sphene powder is 4 μm;

[0074] The chemical composition of the titanium ingot, by mass percentage, includes: SiO2 60%, Al2O3 6%, CaO 18%, TiO2 10%, K2O 2.3%, Na2O 3.1%, MgO 0.4%, and Fe2O3 0.2%.

[0075] The final molar ratio of titanium to calcium in the high-reflectivity heat-insulating ceramic glaze is 1:1.23;

[0076] S300. Firing: The maximum firing temperature during firing is 1200℃, and the firing cycle is 50 minutes.

[0077] After firing, the thickness of each layer of the high-reflectivity heat-insulating ceramic tile was measured. The thickness of the body layer was 3 mm, the thickness of the base glaze layer was 0.1 mm, and the thickness of the high-reflectivity heat-insulating glaze layer was 0.15 mm.

[0078] Example 4

[0079] A high-reflectivity heat-insulating ceramic brick, the preparation method of which includes the following steps:

[0080] S100. Apply a base glaze to the body layer so that a base glaze layer is formed after firing;

[0081] The chemical composition of the base glaze, by mass percentage, includes: SiO2 66%, Al2O3 23%, Na2O 4%, K2O 2.5%, CaO 1.5%, MgO 0.5%, and loss on ignition 2.5%.

[0082] S200. Apply the high-reflectivity heat-insulating ceramic glaze described above onto the base glaze to form a high-reflectivity heat-insulating ceramic glaze layer after firing;

[0083] The raw materials for preparing the high-reflectivity heat-insulating ceramic glaze, by mass percentage, include: 45% titanium frit, 15% titanium sphene powder, 5% titanium dioxide, 9% kaolin, 10% quartz, 10% calcite, 3% talc, 2% zinc oxide, and 1% aluminum oxide.

[0084] Specifically, the average particle size of the titanium sphene powder is 1 μm;

[0085] The chemical composition of the titanium ingot, by mass percentage, includes: SiO2 58%, Al2O3 4%, CaO 19%, TiO2 15%, K2O 1.5%, Na2O 2%, MgO 0.3%, and Fe2O3 0.2%.

[0086] The final molar ratio of titanium to calcium in the high-reflectivity heat-insulating ceramic glaze is 1:1.47;

[0087] S300. Firing: The maximum firing temperature during firing is 1230℃, and the firing cycle is 30 minutes.

[0088] After firing, the thickness of each layer of the high-reflectivity heat-insulating ceramic tile was measured. The thickness of the body layer was 12 mm, the thickness of the base glaze layer was 0.2 mm, and the thickness of the high-reflectivity heat-insulating glaze layer was 0.3 mm.

[0089] Comparative Example 1

[0090] The preparation method of a ceramic tile differs from that of Example 1 in that the raw materials for preparing the high-reflectivity heat-insulating ceramic glaze are different.

[0091] The raw materials for preparing the high-reflectivity heat-insulating ceramic glaze, by mass percentage, include: 50% titanium frit, 4% titanium dioxide, 8% kaolin, 30% quartz, 5% calcite, and 3% talc.

[0092] The final molar ratio of titanium to calcium in the high-reflectivity heat-insulating ceramic glaze is 1:1.58;

[0093] The maximum firing temperature is 1200℃, and the firing cycle is 50 minutes.

[0094] After firing, the thickness of each layer of the high-reflectivity heat-insulating ceramic tile was measured. The thickness of the body layer was 10 mm, the thickness of the base glaze layer was 0.14 mm, and the thickness of the high-reflectivity heat-insulating glaze layer was 0.29 mm.

[0095] Comparative Example 2

[0096] A ceramic brick, the preparation method of which differs from that of Example 1, has a different chemical composition of titanium frit;

[0097] The chemical composition of the titanium ingot, by mass percentage, includes: SiO2 57.7%, Al2O3 9%, CaO 17.6%, TiO2 8%, K2O 2.5%, Na2O 3.5%, MgO 1.5%, and Fe2O3 0.2%.

[0098] The final molar ratio of titanium to calcium in the high-reflectivity heat-insulating ceramic glaze is 1:1.68;

[0099] The maximum firing temperature is 1230℃, and the firing cycle is 30 minutes.

[0100] After firing, the thickness of each layer of the high-reflectivity heat-insulating ceramic tile was measured. The thickness of the body layer was 10 mm, the thickness of the base glaze layer was 0.15 mm, and the thickness of the high-reflectivity heat-insulating glaze layer was 0.28 mm.

[0101] Comparative Example 3

[0102] The preparation method of a ceramic tile differs from that of Example 1 in that the raw materials used to prepare the high-reflectivity heat-insulating ceramic glaze are different.

[0103] The raw materials for preparing the high-reflectivity heat-insulating ceramic glaze, by mass percentage, include: 20% titanium frit, 40% titanium sphene powder, 6% titanium dioxide, 6% kaolin, 10% quartz, 5% albite, 12% wollastonite, and 1% barium carbonate.

[0104] The average particle size of the titanium sphene powder is 3 μm;

[0105] The chemical composition of the titanium ingot, by mass percentage, includes: SiO2 58%, Al2O3 4%, CaO 17%, TiO2 15%, K2O 1.9%, Na2O 2.7%, MgO 1.2%, and Fe2O3 0.2%.

[0106] The final molar ratio of titanium to calcium in the high-reflectivity heat-insulating ceramic glaze is 1:1.18;

[0107] The maximum firing temperature is 1200℃, and the firing cycle is 50 minutes.

[0108] After firing, the thickness of each layer of the high-reflectivity heat-insulating ceramic tile was measured. The thickness of the body layer was 3 mm, the thickness of the base glaze layer was 0.1 mm, and the thickness of the high-reflectivity heat-insulating glaze layer was 0.15 mm.

[0109] Comparative Example 4

[0110] The preparation method of a ceramic tile differs from that of Example 1 in that the raw materials used to prepare the high-reflectivity heat-insulating ceramic glaze are different.

[0111] The raw materials for preparing the high-reflectivity heat-insulating ceramic glaze, by mass percentage, include: 60% titanium frit, 10% titanium sphene powder, 2% titanium dioxide, 8% kaolin, 12% quartz, 5% calcite, and 3% talc.

[0112] The final molar ratio of titanium to calcium in the high-reflectivity heat-insulating ceramic glaze is 1:1.58;

[0113] The maximum firing temperature is 1230℃, and the firing cycle is 30 minutes.

[0114] After firing, the thickness of each layer of the high-reflectivity heat-insulating ceramic tile was measured. The thickness of the body layer was 10 mm, the thickness of the base glaze layer was 0.15 mm, and the thickness of the high-reflectivity heat-insulating glaze layer was 0.28 mm.

[0115] The brightness and gloss of the glaze in Examples 1-4 and Comparative Examples 1-4 were measured.

[0116] According to GB / T 31389-2015, the reflectivity of high-reflectivity heat-insulating ceramic glaze to sunlight across the entire wavelength range is tested.

[0117] The crystal phase composition of the high-reflectivity heat-insulating ceramic glaze was analyzed using X-ray diffraction.

[0118] The size of grains in the high-reflectivity heat-insulating ceramic glaze was analyzed by scanning electron microscopy, and the particle size distribution was statistically analyzed using NanoMeasurer software.

[0119] The corresponding test results are as follows:

[0120] Titanium Sphene Content Solar reflectance Visible light reflectance Near-infrared reflectance Brightness L* gloss Example 1 30％ 0.93 0.93 0.94 95.8 10 Example 2 40％ 0.95 0.95 0.96 96.3 3 Example 3 45％ 0.90 0.91 0.90 95.2 30 Example 4 35％ 0.92 0.93 0.91 95.6 18 Comparative Example 1 21％ 0.83 0.86 0.8 93.6 25 Comparative Example 2 23％ 0.84 0.87 0.83 93.8 8 Comparative Example 3 52％ 0.85 0.88 0.82 94.1 2 Comparative Example 4 26％ 0.85 0.88 0.82 94.2 50

[0121] Based on the test results above, it can be seen that the high reflectance heat-insulating ceramic tiles prepared in Examples 1-4 have high reflectance ratios for all wavelengths of sunlight, all above 0.90, and low gloss. Figure 1 The image shown is the XRD pattern of Example 1. X-ray diffraction analysis revealed that the crystal phase of the high-reflectivity heat-insulating ceramic glaze is mainly granular titanium sphene. Figure 2 The SEM image for Example 1 shows the following particle size distribution of the titanium sphene crystals: approximately 28.5% with a particle size of 300–600 nm, approximately 52.4% with a particle size of 600–900 nm, approximately 13.6% with a particle size of 900–1200 nm, approximately 3.8% with a particle size of 1200–1500 nm, and approximately 1.7% with a particle size of 1500–2000 nm. Figure 3 The graph shows the reflectance curves for Example 1. As can be seen from the graph, the high-reflectance heat-insulating ceramic glaze has a high reflectance for sunlight with wavelengths of 300–2500 nm. According to the formula (see GB / T 31389-2015), the solar reflectance in Example 1 can reach 0.93, the visible light reflectance can reach 0.93, and the near-infrared reflectance can reach 0.94.

[0122] In addition, the particle size distribution of the titanium sphene crystals in Example 2 is as follows: titanium sphene crystals with a particle size of 300-600 nm account for approximately 21.3%, titanium sphene crystals with a particle size of 600-900 nm account for approximately 60.9%, titanium sphene crystals with a particle size of 900-1200 nm account for approximately 14.6%, titanium sphene crystals with a particle size of 1200-1500 nm account for approximately 2.1%, and titanium sphene crystals with a particle size of 1500-2000 nm account for approximately 1.1%.

[0123] In Example 3, the particle size distribution of the titanium sphene crystals was as follows: titanium sphene crystals with a particle size of 300–600 nm accounted for approximately 16.3%, titanium sphene crystals with a particle size of 600–900 nm accounted for approximately 50.3%, titanium sphene crystals with a particle size of 900–1200 nm accounted for approximately 20.6%, titanium sphene crystals with a particle size of 1200–1500 nm accounted for approximately 8.3%, and titanium sphene crystals with a particle size of 1500–2000 nm accounted for approximately 4.5%.

[0124] In Example 4, the particle size distribution of the titanium sphene crystals was as follows: titanium sphene crystals with a particle size of 300–600 nm accounted for approximately 27.6%, titanium sphene crystals with a particle size of 600–900 nm accounted for approximately 50.8%, titanium sphene crystals with a particle size of 900–1200 nm accounted for approximately 13.8%, titanium sphene crystals with a particle size of 1200–1500 nm accounted for approximately 5.3%, and titanium sphene crystals with a particle size of 1500–2000 nm accounted for approximately 2.5%.

[0125] Figure 4 The image shows the SEM image of Comparative Example 1. As can be seen from the image, in the high-reflectivity heat-insulating ceramic glaze layer of Comparative Example 1, the particle size distribution of titanium sphene crystals is 100-500 nm, of which titanium sphene crystals with a particle size of 100-300 nm account for about 81.5% and titanium sphene crystals with a particle size of 300-500 nm account for about 18.5%. Figure 5 The graph shows the reflectance of Comparative Example 1. It can be seen that the high-reflectance thermal insulation ceramic glaze of Comparative Example 1 has high reflectance for short-wavelength sunlight, but low reflectance for sunlight with wavelengths greater than 500nm. According to the formula, the solar reflectance in Comparative Example 1 is only 0.83, the visible light reflectance is only 0.86, and the near-infrared reflectance is only 0.8. This indicates that when the content of titanium sphene crystals is low and the particle size range is too small, the high-reflectance thermal insulation ceramic glaze will have relatively low reflectance for certain wavelengths of sunlight. The reason why the particle size of titanium sphene crystals is concentrated between 100 and 500nm is that titanium sphene powder was not used as a raw material in Comparative Example 1, resulting in a lack of larger titanium sphene crystals in the glaze layer.

[0126] In Comparative Example 2, the Al2O3 content of its titanium fused mass is greater than the scope of protection of this invention, while its TiO2 content is less than the scope of protection of this invention. Analysis shows that the particle size distribution of the titanium sphene crystals in Comparative Example 2 is between 100 and 1000 nm, with approximately 25.3% of the titanium sphene crystals having a particle size of 100–300 nm, approximately 37.5% having a particle size of 300–600 nm, and approximately 37.2% having a particle size of 600–1000 nm. For sunlight with wavelengths greater than 1000 nm, its reflectivity is low, and its titanium sphene content is only 23%. Therefore, the solar reflectance, visible light reflectance, and near-infrared reflectance of Comparative Example 2 are significantly lower than those of Examples 1-4. Comparative Example 2 demonstrates that when the TiO2 content in the titanium fused mass is too low and the Al2O3 content is too high, it is not conducive to the precipitation of large-particle titanium sphene crystals. The reason is that titanium frit has a strong melting ability at high temperatures, which can melt most of the titanium dioxide and titanium sphene powder. In the eutectic, Ti reacts with Ca, Si and O elements to form titanium sphene crystals. If the content of Al2O3 in the titanium frit is too high, it will lead to excessive viscosity of the eutectic, which is not conducive to the precipitation and growth of titanium sphene crystals.

[0127] In Comparative Example 3, the content of titanium frit is less than the scope of protection of this invention, while the content of titanium sphene powder is greater than the scope of protection of this invention. Analysis shows that the titanium sphene content in Comparative Example 3 is higher than that in Examples 1-4. The particle size distribution of titanium sphene crystals in Comparative Example 3 is 500-4000 nm, of which the number of titanium sphene crystals with a particle size of 500-900 nm accounts for about 23.5%, the number of titanium sphene crystals with a particle size of 900-1200 nm accounts for about 35.7%, the number of titanium sphene crystals with a particle size of 1200-1500 nm accounts for about 17.2%, the number of titanium sphene crystals with a particle size of 1500-2000 nm accounts for about 13.4%, and the number of titanium sphene crystals with a particle size of 2000-4000 nm accounts for about 10.2%. This indicates that excessive use of titanium sphene powder and insufficient use of titanium frit will result in an excessive amount of large-diameter titanium sphene crystals and an insufficient amount of small-diameter titanium sphene crystals in the glaze layer. The reason is that insufficient use of titanium frit results in a low content of eutectic and weak melting ability, limiting the melting of titanium sphene powder and leading to a larger titanium sphene crystal size in the glaze layer.

[0128] In Comparative Example 4, the content of titanium frit exceeded the scope of protection of this invention. Analysis showed that the particle size distribution of the titanium sphene crystals in Comparative Example 4 was between 100 and 1000 nm, with approximately 33.5% having a particle size of 100–300 nm, approximately 38.3% having a particle size of 300–600 nm, and approximately 28.2% having a particle size of 600–1000 nm. This indicates that excessive titanium frit content leads to excessively small particle size of the precipitated titanium sphene crystals. The reason is that when the titanium frit content is too high, the melting ability of the eutectic is strong, which is detrimental to the growth of titanium sphene crystals.

[0129] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A highly reflective, heat-insulating ceramic glaze, characterized by, The preparation raw materials of the high-reflective heat-insulating ceramic glaze include, in percentage by mass, titanium fused block 30-50%, titanium sphene powder 10-30%, and titanium white powder 4-7.5%.

2. The highly reflective, insulating ceramic glaze of claim 1, wherein, The molar ratio of titanium to calcium in the preparation raw materials of the high-reflective heat-insulating ceramic glaze is 1:1-1:1.

5.

3. The highly reflective, insulating ceramic glaze of claim 1, wherein, The preparation raw materials further include one or more of quartz, albite, potassium feldspar, alumina, calcite, kaolin, talc, dolomite, wollastonite, barium carbonate, strontium carbonate, and zinc oxide.

4. The highly reflective, insulating ceramic glaze of claim 1, wherein, The preparation raw materials include, in percentage by mass, titanium fused block 50%, titanium sphene powder 10%, titanium white powder 4%, kaolin 8%, quartz 20%, calcite 5%, and talc 3%.

5. The highly reflective, insulating ceramic glaze of claim 1, wherein, The preparation raw materials include, in percentage by mass, titanium fused block 40%, titanium sphene powder 20%, titanium white powder 7.5%, kaolin 6%, quartz 12%, potassium feldspar 5%, dolomite 8%, and strontium carbonate 1.5%.

6. The highly reflective, insulating ceramic glaze of claim 1, wherein, The preparation raw materials include, in percentage by mass, titanium fused block 30%, titanium sphene powder 30%, titanium white powder 6%, kaolin 6%, quartz 10%, albite 5%, wollastonite 12%, and barium carbonate 1%.

7. The highly reflective, insulating ceramic glaze of claim 1, wherein, The preparation raw materials include, in percentage by mass, titanium fused block 45%, titanium sphene powder 15%, titanium white powder 5%, kaolin 9%, quartz 10%, calcite 10%, talc 3%, zinc oxide 2%, and alumina 1%.

8. The high reflective, insulating ceramic glaze according to any one of claims 1 to 7, characterized in that, The firing temperature is 1170-1230 DEG C, and the firing period is 30-90 minutes.

Images