Solar reflection type double-core energy-saving composite light ceramic tile and preparation method thereof

Abstract

This invention discloses a solar-reflective dual-core energy-saving composite lightweight ceramic brick and its preparation method. The composite lightweight ceramic brick includes a lightweight ceramic brick matrix, the upper surface of which is provided with a solar-reflective glaze layer; the lower surface of the lightweight ceramic brick matrix is ​​provided with a first aerogel coating and a second aerogel coating from the inside out, and a three-dimensional mesh-like air insulation structure is formed between the first aerogel coating and the second aerogel coating. This invention, on the one hand, utilizes the solar-reflective glaze layer to reflect visible and infrared light, reducing the surface temperature and internal temperature difference of the brick, extending the service life of the brick, and improving the aesthetics and personalization of the building; on the other hand, it utilizes the double-layer aerogel coating and the air insulation layer formed between the coatings to reduce the thermal conductivity of the brick, block heat transfer, avoid the thermal bridging effect, and improve the thermal insulation performance of the brick, thereby effectively reducing heat loss from the building's exterior walls.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a sunlight-reflective dual-core energy-saving composite lightweight ceramic brick and its preparation method. Background Technology

[0002] Building energy conservation refers to the adoption of various technical measures during building design, construction, and use to reduce building energy consumption, improve building energy efficiency, and reduce environmental pollution and impact. The main aspects of building energy conservation include the building's thermal performance, lighting and ventilation, heating and air conditioning, hot water supply, and solar energy utilization.

[0003] One important way to achieve energy conservation in buildings is to improve their thermal insulation performance, that is, to reduce heat loss and energy consumption for heating and cooling. The thermal insulation performance of a building depends primarily on the thermal conductivity and thickness of the building materials, as well as the building's structural form and details. Therefore, developing and using building materials with low thermal conductivity and high-efficiency insulation properties is an effective way to improve building insulation performance.

[0004] Currently, commonly used building insulation materials on the market mainly include insulating mortar, rock wool, glass wool, polystyrene foam, and polyurethane foam. These materials generally have a thermal conductivity between 0.03 and 0.06 W / m·K, providing some insulation effect, but they also have some shortcomings, as detailed below:

[0005] Thermal insulation mortar: Thermal insulation mortar is a dry-mixed mortar made of cement, sand, thermal insulation filler and additives. It has the advantages of convenient construction, strong adaptability and low cost, but it also has the disadvantages of low thermal insulation performance, easy cracking, low strength and poor durability.

[0006] Rock wool: Rock wool is an inorganic fiber material made from molten rock fibers. It has advantages such as low thermal conductivity, good sound insulation and fire resistance, but it also has disadvantages such as high water absorption, easy dampness, easy corrosion and easy dust generation.

[0007] Glass wool: Glass wool is an inorganic fiber material made from molten glass fibers. It has advantages such as low thermal conductivity, good sound insulation and fire resistance, but it also has disadvantages such as high water absorption, easy dampness, easy corrosion and easy dust generation.

[0008] Polystyrene foam: Polystyrene foam is an organic foam material made of polystyrene resin by foaming with a foaming agent. It has advantages such as low thermal conductivity, light weight and high strength, but also disadvantages such as flammability, easy aging, easy shrinkage and easy pollution.

[0009] Polyurethane foam: Polyurethane foam is an organic foam material made from raw materials such as polyisocyanate and polyols by foaming with a foaming agent. It has the advantages of low thermal conductivity, light weight and high strength, but also has the disadvantages of being flammable, easy to age, easy to shrink and easy to pollute.

[0010] In addition to the insulation materials mentioned above, some new insulation materials are under research and development and being applied, such as aerogel, vacuum insulation boards, and phase change materials. These materials generally have a thermal conductivity of less than 0.01 W / m·K and have advantages such as high insulation performance, light weight, and good energy-saving effect, but they also have disadvantages such as high cost, difficult construction, and poor stability.

[0011] Meanwhile, energy conservation and thermal insulation of building exterior walls are important aspects of building energy conservation, as well as crucial factors for building aesthetics and comfort. Traditional building exterior wall materials, such as cement, bricks, tiles, and stone, typically have high heat absorption and low thermal insulation performance, resulting in a large temperature difference between the surface and interior of the building exterior walls. This not only affects the building's energy efficiency but also its lifespan and aesthetics.

[0012] Therefore, existing building insulation materials still need improvement in terms of insulation performance, aesthetics, and energy saving. There is an urgent need to develop a building exterior wall insulation material that can meet the insulation needs of buildings while also improving their aesthetics and energy-saving effects. Summary of the Invention

[0013] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a sunlight-reflective dual-core energy-saving composite lightweight ceramic brick and its preparation method. The composite lightweight ceramic brick can effectively reduce the heat absorption and heat loss of building exterior walls, improve the energy-saving and thermal insulation performance of buildings, and at the same time has the characteristics of being lightweight and high-strength, making it suitable for the decoration and protection of various building exterior walls.

[0014] To solve the above-mentioned technical problems, the first aspect of the present invention provides a composite lightweight ceramic brick, comprising a lightweight ceramic brick substrate, wherein the upper surface of the lightweight ceramic brick substrate is provided with a sunlight-reflecting glaze layer; and the lower surface of the lightweight ceramic brick substrate is provided with a first aerogel coating and a second aerogel coating from the inside to the outside, wherein a three-dimensional mesh air insulation structure is formed between the first aerogel coating and the second aerogel coating.

[0015] Specifically, the lightweight ceramic brick substrate of the present invention has a sunlight-reflecting glaze layer and a double-layer aerogel coating on its upper and lower surfaces, respectively. On the one hand, the sunlight-reflecting glaze layer on the upper surface can effectively reflect visible and infrared light, reducing the surface temperature and internal temperature difference of the brick, extending the service life of the brick, and improving the aesthetics and personalization of the building. On the other hand, the double-layer aerogel coating on the lower surface has a low thermal conductivity and high-efficiency heat insulation function; moreover, the double-layer aerogel coating forms a three-dimensional mesh air insulation structure, which can block heat transfer, avoid the thermal bridging effect, improve the heat insulation performance of the brick, thereby effectively reducing heat loss from the building's exterior walls and saving energy. In addition, the lightweight ceramic brick substrate is lightweight, which can reduce the building's load and improve the building's safety.

[0016] As a further improvement to the above scheme, the sunlight-reflecting glaze layer is made by firing sunlight-reflecting glaze, and the raw materials for preparing the sunlight-reflecting glaze include sunlight-reflecting oxides and thermochromic materials, wherein the thermochromic materials include vanadium oxides.

[0017] Specifically, thermochromic materials are materials that change color with temperature. Their color-changing principle utilizes the changes in electronic or crystal structure caused by phase transitions or chemical reactions, thus affecting light absorption or scattering. For example, vanadium oxide is yellow at low temperatures, gradually changing to orange, red, purple, and blue as the temperature rises, eventually becoming black. This is because vanadium oxide undergoes different redox reactions at different temperatures, leading to changes in the oxidation and valence states of vanadium, thereby altering its light reflectivity. Therefore, this invention, by adding thermochromic vanadium oxide to a sunlight-reflective glaze, allows the reflectivity of the brick to change with temperature. When sunlight is strong and the brick surface temperature rises, the color of the thermochromic material deepens, and the reflectivity decreases, thereby reducing the heat absorption of the brick, reducing the internal temperature difference, and extending the brick's lifespan. When sunlight is weak and the brick surface temperature decreases, the color of the thermochromic material lightens, and the reflectivity increases, thereby increasing the reflected light of the brick and improving the aesthetics and personalization of the building. Meanwhile, the composite lightweight ceramic brick of the present invention has an intelligent adjustment function, which can adapt to different sunlight conditions and seasons, adjust the reflectivity of the brick, realize the intelligent adjustment function of the brick, and improve the energy saving and comfort of the building.

[0018] Preferably, the mass ratio of the solar reflective oxide to the thermochromic material is (5-25):1.

[0019] Preferably, the solar reflective oxide includes at least one of tin oxide, aluminum oxide, calcium oxide, magnesium oxide, silicon oxide, titanium oxide, and iron oxide.

[0020] As a further improvement to the above scheme, the raw material components of the sunlight reflective glaze, by weight, include: 40-60 parts tin oxide, 10-20 parts aluminum oxide, 5-15 parts calcium oxide, 5-15 parts magnesium oxide, 5-15 parts silicon oxide, 2-10 parts titanium oxide, 0.1-1 parts iron oxide, and 5-15 parts vanadium oxide.

[0021] Specifically, tin oxide, aluminum oxide, calcium oxide, magnesium oxide, silicon oxide, titanium oxide, and iron oxide all possess high reflectivity, effectively reflecting visible and infrared light and reducing the surface temperature and internal temperature difference of the brick. Furthermore, the reflectivity of different oxides varies with wavelength; for example, aluminum oxide and zinc oxide have high reflectivity in the visible and near-infrared regions, while magnesium oxide and titanium oxide have higher reflectivity in the mid-infrared and far-infrared regions. Therefore, this invention selects oxides with different reflectivity wavelengths as sunlight-reflecting materials and rationally optimizes the ratio of each raw material, allowing the reflective characteristics of various oxides to complement each other, forming a wide-band high-reflectivity region, thereby improving the reflectivity of the brick and reducing its heat absorption.

[0022] As a further improvement to the above solution, the first aerogel coating is formed by drying and curing a first aerogel coating material. The raw material components of the first aerogel coating material include, by weight, 5-15 parts of aerogel powder, 1-3 parts of adhesive and 6-10 parts of diluent.

[0023] Specifically, the aerogel coating prepared by this invention can be bonded to a lightweight ceramic brick substrate through coating, forming a dual-core energy-saving system with the sunlight-reflecting glaze layer, thereby effectively improving the thermal insulation performance and energy-saving effect of the ceramic brick. Compared with conventional aerogel composite materials, such as aerogel boards or aerogel felts, aerogel coatings have better adhesion and higher utilization rates.

[0024] As a further improvement to the above solution, the second aerogel coating is formed by drying and curing a second aerogel coating material, and the raw material components of the second aerogel coating material are the same as those of the first aerogel coating material.

[0025] Preferably, the adhesive is polyvinyl alcohol.

[0026] Preferably, the diluent is water.

[0027] As a further improvement to the above scheme, the raw material components of the aerogel powder, by weight, include: 5-15 parts sodium silicate, 3-8 parts aluminum silicate, 1-3 parts formaldehyde and 0.5-1.5 parts sulfuric acid.

[0028] Specifically, the aerogel powder of the present invention uses sodium silicate and aluminum silicate as the main raw materials. Under the combined action of sodium silicate and aluminum silicate, a three-dimensional network structure with high strength and low density is formed. Compared with single silica aerogel, the aerogel of the present invention has better mechanical properties and lower thermal conductivity.

[0029] Preferably, the aerogel powder is prepared by a sol-gel method, the preparation process of which includes: mixing sodium silicate, aluminum silicate, formaldehyde and sulfuric acid in a mass ratio and preparing a sol under neutral conditions; then gelling the prepared sol and drying it to obtain the aerogel powder.

[0030] Specifically, this invention uses the sol-gel method to prepare aerogel powder, eliminating the need for organic solvents or catalysts, thus reducing preparation costs and environmental pollution. Compared to conventional aerogel preparation methods, such as supercritical drying or freeze-drying, the sol-gel method is simpler, more energy-efficient, and environmentally friendly.

[0031] Preferably, the aerogel powder has an average particle size of 5-15 μm.

[0032] As a further improvement to the above solution, the thickness of both the first and second aerogel coatings is 1-4 mm. By controlling the thickness of the aerogel coatings, optimal thermal insulation can be achieved while ensuring lightweight design.

[0033] Preferably, the thickness of the first aerogel coating is 1-2 mm.

[0034] Preferably, the thickness of the second aerogel coating is 2-4 mm.

[0035] As a further improvement to the above solution, the thickness of the lightweight ceramic brick matrix is ​​8-10 mm. By controlling the thickness of the lightweight ceramic brick matrix, material consumption can be reduced while ensuring the strength of the brick.

[0036] Preferably, the bulk density of the lightweight ceramic brick is 0.8-1.2 g / cm³. 3 .

[0037] Preferably, the raw material components of the lightweight ceramic brick body include, by weight, 50-70 parts kaolin, 10-30 parts quartz, 5-15 parts feldspar, and 5-15 parts calcareous clay.

[0038] A second aspect of the present invention provides a method for preparing the above-mentioned composite lightweight ceramic brick, comprising the following steps:

[0039] (1) Mix the raw materials for preparing lightweight ceramic brick substrate, make them into powder, press them into shape, and obtain lightweight ceramic brick blank; then apply sunlight-reflecting glaze to the upper surface of the lightweight ceramic brick blank, and fire it to obtain a lightweight ceramic brick substrate containing a sunlight-reflecting glaze layer.

[0040] (2) First, a first aerogel coating is applied to the lower surface of the lightweight ceramic brick substrate obtained in step (1), and then dried and cured to form a first aerogel coating; then a second aerogel coating is applied to the lower surface of the first aerogel coating, and dried and cured to form a second aerogel coating, thus obtaining the composite lightweight ceramic brick.

[0041] Preferably, in step (1), the firing temperature is 1000-1100℃ and the firing time is 30min.

[0042] Preferably, in step (2), the drying and curing temperature is 50-70℃ and the drying and curing time is 1-3 hours.

[0043] A third aspect of the present invention provides the application of the above-described composite lightweight ceramic bricks in building exterior walls.

[0044] Compared with the prior art, the above-described technical solution of the present invention has at least the following technical effects or advantages:

[0045] (1) The composite ceramic lightweight brick of the present invention includes a lightweight ceramic brick matrix. By applying a sunlight-reflecting glaze and coating a double-layer aerogel coating on the upper and lower surfaces of the lightweight ceramic brick matrix, a dual-core energy-saving system is formed. On the one hand, the sunlight-reflecting glaze layer reflects visible light and infrared light, reducing the surface temperature and internal temperature difference of the brick, extending the service life of the brick, and improving the aesthetics and personalization of the building. On the other hand, the double-layer aerogel coating on the lower surface and the air insulation layer formed between the coatings reduce the thermal conductivity of the brick, block the heat transfer, avoid the thermal bridging effect, and improve the thermal insulation performance of the brick, thereby effectively reducing the heat loss of the building's exterior walls and saving energy.

[0046] (2) The composite ceramic lightweight ceramic brick prepared by the present invention has high solar reflectivity, low heat loss, excellent thermal insulation performance, and the product can simultaneously be lightweight and high-strength. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the structure of the composite lightweight ceramic brick prepared according to the present invention. Detailed Implementation

[0048] The present invention will now be described in detail with reference to embodiments to facilitate understanding of the invention by those skilled in the art. It is particularly important to note that the embodiments are merely illustrative of the invention and should not be construed as limiting the scope of protection of the invention. Non-essential improvements and adjustments made to the invention by those skilled in the art based on the above description should still fall within the scope of protection of the invention. Furthermore, all raw materials mentioned below, unless otherwise specified, are commercially available products; all process steps or preparation methods not mentioned in detail are process steps or preparation methods known to those skilled in the art.

[0049] Schematic diagrams of the composite lightweight ceramic bricks prepared according to various embodiments of the present invention are shown below. Figure 1 As shown, from top to bottom, it includes a sunlight-reflecting glaze layer 101, a lightweight ceramic tile substrate 102, a first aerogel coating 103, and a second aerogel coating 104, and a three-dimensional mesh air insulation structure is formed between the first aerogel coating 103 and the second aerogel coating 104.

[0050] Example 1

[0051] A composite lightweight ceramic brick includes a lightweight ceramic brick substrate, and the upper surface of the lightweight ceramic brick substrate is provided with a sunlight-reflecting glaze layer; the lower surface of the lightweight ceramic brick substrate is provided with a first aerogel coating and a second aerogel coating from the inside to the outside, and a three-dimensional mesh air insulation structure is formed between the first aerogel coating and the second aerogel coating.

[0052] The thicknesses of the first aerogel coating and the second aerogel coating are 1 mm and 2 mm, respectively, and the thickness of the lightweight ceramic brick substrate is 10 mm.

[0053] The sunlight-reflective glaze is made by firing sunlight-reflective glaze. The raw materials for preparing the sunlight-reflective glaze, by weight, include: 50 parts tin oxide, 15 parts aluminum oxide, 10 parts calcium oxide, 10 parts magnesium oxide, 10 parts silicon oxide, 4 parts titanium oxide, 0.5 parts iron oxide, and 10 parts vanadium pentoxide.

[0054] The raw materials for preparing the lightweight ceramic brick matrix include, by weight: 50 parts kaolin, 25 parts quartz, 15 parts feldspar, and 10 parts calcareous clay.

[0055] The first aerogel coating and the second aerogel coating are formed by drying and curing the first aerogel coating and the second aerogel coating, respectively, and the raw material components of the first aerogel coating are the same as those of the second aerogel coating.

[0056] The raw material components of the first aerogel coating, by weight, include: 10 parts aerogel powder, 2 parts polyvinyl alcohol, and 8 parts water.

[0057] The raw material components of the aerogel powder, by weight, include: 10 parts sodium silicate, 5 parts aluminum silicate, 2 parts formaldehyde and 1 part sulfuric acid.

[0058] A method for preparing composite lightweight ceramic bricks includes the following steps:

[0059] (1) Mix the raw materials for preparing the lightweight ceramic brick matrix according to the mass ratio, and add water to the ball mill at a speed of 500 r / min (the mass ratio of material to water is 10:4) for 2 hours; then spray granulation to produce powder with an average particle size of 100 μm, and press it to obtain the lightweight ceramic brick blank;

[0060] (2) Mix the raw materials for preparing the sunlight reflective glaze according to the mass ratio, add water and sodium carboxymethyl cellulose additive at a speed of 1000 r / min and ball mill (the mass ratio of material, water and additive is 10:5:0.5) for 1 hour to obtain a sunlight reflective glaze slurry with a viscosity of 2000 mPa·s at room temperature.

[0061] (3) Apply the sunlight-reflecting glaze slurry prepared in step (2) to the surface of the lightweight ceramic brick body obtained in step (1), dry it, and then fire it in a kiln at 1050℃ for 30 minutes to obtain a lightweight ceramic brick matrix containing a sunlight-reflecting glaze layer.

[0062] (4) Mix the raw materials for preparing aerogel powder according to the mass ratio, put them into a sol machine, and stir at 300 r / min for 30 min under neutral conditions to prepare a sol with a viscosity of 1000 mPa·s at room temperature; then put the prepared sol into a gel machine and gel at 60℃ for 2 hours to obtain aerogel; then put it into a dryer and dry at 80℃ for 4 hours to obtain aerogel powder with an average particle size of 10 μm.

[0063] (5) The aerogel powder obtained in step (4) is mixed with polyvinyl alcohol and water in a mass ratio and stirred at a speed of 200 r / min for 10 min to obtain an aerogel coating with a viscosity of 1000 mPa·s at room temperature.

[0064] (6) First, coat the other side of the lightweight ceramic brick substrate obtained in step (3) with 2 mm of the aerogel coating obtained in step (5), and dry and cure at 60°C for 2 hours to form a 1 mm thick first aerogel coating; then coat the other side with 4 mm of the aerogel coating obtained in step (5), and dry and cure at 60°C for 2 hours to form a 2 mm thick second aerogel coating, and form a three-dimensional mesh air insulation structure between the first aerogel coating and the second aerogel coating to obtain the composite lightweight ceramic brick of this embodiment.

[0065] Example 2

[0066] A composite lightweight ceramic brick includes a lightweight ceramic brick substrate, and the upper surface of the lightweight ceramic brick substrate is provided with a sunlight-reflecting glaze layer; the lower surface of the lightweight ceramic brick substrate is provided with a first aerogel coating and a second aerogel coating from the inside to the outside, and a three-dimensional mesh air insulation structure is formed between the first aerogel coating and the second aerogel coating.

[0067] The thicknesses of the first aerogel coating and the second aerogel coating are 2 mm and 4 mm, respectively, and the thickness of the lightweight ceramic brick substrate is 8 mm.

[0068] The sunlight-reflective glaze is made by firing sunlight-reflective glaze. The raw materials for preparing the sunlight-reflective glaze, by weight, include: 45 parts tin oxide, 12 parts aluminum oxide, 8 parts calcium oxide, 8 parts magnesium oxide, 12 parts silicon oxide, 8 parts titanium oxide, 0.2 parts iron oxide, and 6.8 parts vanadium pentoxide.

[0069] The raw materials for preparing the lightweight ceramic brick matrix include, by weight: 60 parts kaolin, 20 parts quartz, 10 parts feldspar, and 10 parts calcareous clay.

[0070] The first aerogel coating and the second aerogel coating are formed by drying and curing the first aerogel coating and the second aerogel coating, respectively, and the raw material components of the first aerogel coating are the same as those of the second aerogel coating.

[0071] The raw material components of the first aerogel coating, by weight, include: 9 parts aerogel powder, 3 parts polyvinyl alcohol, and 8 parts water.

[0072] The raw material components of the aerogel powder, by weight, include: 11 parts sodium silicate, 4 parts aluminum silicate, 2 parts formaldehyde and 1 part sulfuric acid.

[0073] A method for preparing composite lightweight ceramic bricks includes the following steps:

[0074] (1) Mix the raw materials for preparing the lightweight ceramic brick matrix according to the mass ratio, and add water to the ball mill at a speed of 500 r / min (the mass ratio of material to water is 10:4) for 2 hours; then spray granulation to produce powder with an average particle size of 100 μm, and press it to obtain the lightweight ceramic brick blank;

[0075] (2) Mix the raw materials for preparing the sunlight reflective glaze according to the mass ratio, add water and sodium carboxymethyl cellulose additive at a speed of 1000 r / min and ball mill (the mass ratio of material, water and additive is 10:5:0.5) for 1 hour to obtain a sunlight reflective glaze slurry with a viscosity of 2000 mPa·s at room temperature.

[0076] (3) Apply the sunlight-reflecting glaze slurry prepared in step (2) to the surface of the lightweight ceramic brick body obtained in step (1), dry it, and then fire it in a kiln at 1080℃ for 30 minutes to obtain a lightweight ceramic brick matrix containing a sunlight-reflecting glaze layer.

[0077] (4) Mix the raw materials for preparing aerogel powder according to the mass ratio, put them into a sol machine, and stir at 300 r / min for 30 min under neutral conditions to prepare a sol with a viscosity of 1000 mPa·s at room temperature; then put the prepared sol into a gel machine and gel at 60℃ for 2 hours to obtain aerogel; then put it into a dryer and dry at 80℃ for 4 hours to obtain aerogel powder with an average particle size of 10 μm.

[0078] (5) The aerogel powder obtained in step (4) is mixed with polyvinyl alcohol and water in a mass ratio and stirred at a speed of 200 r / min for 10 min to obtain an aerogel coating with a viscosity of 1000 mPa·s at room temperature.

[0079] (6) First, coat the other side of the lightweight ceramic brick substrate obtained in step (3) with 2 mm of the aerogel coating obtained in step (5), and dry and cure at 60°C for 2 hours to form a 1 mm thick first aerogel coating; then coat the other side with 4 mm of the aerogel coating obtained in step (5), and dry and cure at 60°C for 2 hours to form a 2 mm thick second aerogel coating, and form a three-dimensional mesh air insulation structure between the first aerogel coating and the second aerogel coating to obtain the composite lightweight ceramic brick of this embodiment.

[0080] Example 3

[0081] A composite lightweight ceramic brick includes a lightweight ceramic brick substrate, and the upper surface of the lightweight ceramic brick substrate is provided with a sunlight-reflecting glaze layer; the lower surface of the lightweight ceramic brick substrate is provided with a first aerogel coating and a second aerogel coating from the inside to the outside, and a three-dimensional mesh air insulation structure is formed between the first aerogel coating and the second aerogel coating.

[0082] The thicknesses of the first aerogel coating and the second aerogel coating are 1 mm and 4 mm, respectively, and the thickness of the lightweight ceramic brick substrate is 9 mm.

[0083] The sunlight-reflective glaze is made by firing sunlight-reflective glaze. The raw materials for preparing the sunlight-reflective glaze, by weight, include: 55 parts tin oxide, 13 parts aluminum oxide, 12 parts calcium oxide, 5 parts magnesium oxide, 7 parts silicon oxide, 2 parts titanium oxide, 0.3 parts iron oxide, and 5.7 parts vanadium pentoxide.

[0084] The raw materials for preparing the lightweight ceramic brick matrix include, by weight: 50 parts kaolin, 30 parts quartz, 5 parts feldspar, and 15 parts calcareous clay.

[0085] The first aerogel coating and the second aerogel coating are formed by drying and curing the first aerogel coating and the second aerogel coating, respectively, and the raw material components of the first aerogel coating are the same as those of the second aerogel coating.

[0086] The raw material components of the first aerogel coating, by weight, include: 9 parts aerogel powder, 3 parts polyvinyl alcohol, and 8 parts water.

[0087] The raw material components of the aerogel powder, by weight, include: 11 parts sodium silicate, 4 parts aluminum silicate, 2 parts formaldehyde and 1 part sulfuric acid.

[0088] A method for preparing composite lightweight ceramic bricks includes the following steps:

[0089] (1) Mix the raw materials for preparing the lightweight ceramic brick matrix according to the mass ratio, and add water to the ball mill at a speed of 500 r / min (the mass ratio of material to water is 10:4) for 2 hours; then spray granulation to produce powder with an average particle size of 100 μm, and press it to obtain the lightweight ceramic brick blank;

[0090] (2) Mix the raw materials for preparing the sunlight reflective glaze according to the mass ratio, add water and sodium carboxymethyl cellulose additive at a speed of 1000 r / min and ball mill (the mass ratio of material, water and additive is 10:5:0.5) for 1 hour to obtain a sunlight reflective glaze slurry with a viscosity of 2000 mPa·s at room temperature.

[0091] (3) Apply the sunlight-reflecting glaze slurry prepared in step (2) to the surface of the lightweight ceramic brick body obtained in step (1), dry it, and then fire it in a kiln at 1075℃ for 30 minutes to obtain a lightweight ceramic brick matrix containing a sunlight-reflecting glaze layer.

[0092] (4) Mix the raw materials for preparing aerogel powder according to the mass ratio, put them into a sol machine, and stir at 300 r / min for 30 min under neutral conditions to prepare a sol with a viscosity of 1000 mPa·s at room temperature; then put the prepared sol into a gel machine and gel at 60℃ for 2 hours to obtain aerogel; then put it into a dryer and dry at 80℃ for 4 hours to obtain aerogel powder with an average particle size of 10 μm.

[0093] (5) The aerogel powder obtained in step (4) is mixed with polyvinyl alcohol and water in a mass ratio and stirred at a speed of 200 r / min for 10 min to obtain an aerogel coating with a viscosity of 1000 mPa·s at room temperature.

[0094] (6) First, coat the other side of the lightweight ceramic brick substrate obtained in step (3) with 2 mm of the aerogel coating obtained in step (5), and dry and cure at 60°C for 2 hours to form a 1 mm thick first aerogel coating; then coat the other side with 4 mm of the aerogel coating obtained in step (5), and dry and cure at 60°C for 2 hours to form a 2 mm thick second aerogel coating, and form a three-dimensional mesh air insulation structure between the first aerogel coating and the second aerogel coating to obtain the composite lightweight ceramic brick of this embodiment.

[0095] Comparative Example 1

[0096] The only difference between Comparative Example 1 and Example 1 is that the composite lightweight ceramic tile of Comparative Example 1 does not contain a sunlight-reflecting glaze layer.

[0097] Comparative Example 2

[0098] The only difference between Comparative Example 2 and Example 1 is that the composite lightweight ceramic brick of Comparative Example 2 does not contain the first aerogel coating and the second aerogel coating.

[0099] Comparative Example 3

[0100] The only difference between Comparative Example 3 and Example 1 is that the composite lightweight ceramic brick of Comparative Example 3 does not contain a second aerogel coating.

[0101] Comparative Example 4

[0102] The only difference between Comparative Example 4 and Example 1 is that the raw material components of the sunlight-reflecting glaze of the composite lightweight ceramic tile in Comparative Example 4 do not contain vanadium pentoxide.

[0103] Comparative Example 5

[0104] The only difference between Comparative Example 5 and Example 1 is that the aerogel powder of the composite lightweight ceramic brick in Comparative Example 5 does not contain sodium silicate in its raw material composition.

[0105] Performance testing

[0106] The composite lightweight ceramic brick samples prepared in Examples 1-3 and Comparative Examples 1-5 were subjected to relevant performance tests, and the test results are shown in Table 1.

[0107] The reflectivity test is conducted according to Part 1 of the standard GJB 5023.1A-2012, "Test Methods for Reflectivity and Emissivity of Materials and Coatings." Reflectivity refers to the proportion of solar radiation reflected by a material's surface, usually expressed as a percentage. Higher reflectivity means less solar energy is absorbed by the surface, resulting in a lower surface temperature. The basic principle of reflectivity testing involves using a spectrometer or reflectometer to measure the material's reflection spectrum at different wavelengths, and then calculating the reflectivity based on the spectral distribution of solar radiation and the visual response of the human eye.

[0108] Additional thermal resistance testing is conducted according to the thermal resistance and heat capacity ratio method in the standard GB / T 20311-2021 Test Methods for Thermal Performance of Buildings. Additional thermal resistance refers to the extra thermal resistance generated by a material due to its surface or structural characteristics, in addition to its inherent thermal resistance. Additional thermal resistance can reduce the thermal conductivity of a material, thereby improving its thermal insulation performance. The basic principle of the additional thermal resistance testing standard is to measure the heat flux density and temperature difference of the material under steady-state conditions using a heat flow meter or hot plate method, and then calculate the thermal resistance and additional thermal resistance based on the material's thickness and area.

[0109] The flexural strength was tested according to the test methods in GB / T3810.4-2016 Test Methods for Ceramic Tiles.

[0110] Table 1: Performance Test Comparison Table of Examples 1-3 and Comparative Examples 1-5

[0111]

[0112] As shown in Table 1, the composite lightweight ceramic brick samples prepared in Examples 1-3 of this invention all exhibit high solar reflectivity, low heat loss, and excellent thermal insulation performance. Furthermore, the products simultaneously possess both lightweight and high strength, achieving a flexural strength of 15.6-18.2 MPa, a reflectivity of 85.2-87.6%, a thermal resistance of 0.8-1.0, and an additional thermal resistance of 0.6-0.8. In contrast, Comparative Examples 1-5, compared to Example 1, show inferior overall performance due to the different raw material compositions of the absence of solar reflective glaze, gel coating, solar reflective glaze, and aerogel powder, respectively.

[0113] For those skilled in the art, several simple deductions or substitutions can be made without departing from the inventive concept, without requiring creative effort. Therefore, any simple improvements made to this invention by those skilled in the art based on the disclosure of this invention should be within the scope of protection of this invention. The above embodiments are preferred embodiments of this invention, and all processes similar to this invention and equivalent changes should fall within the scope of protection of this invention.

Claims

1. A composite lightweight ceramic brick, characterized in that, The material includes a lightweight ceramic brick substrate, the upper surface of which is provided with a sunlight-reflecting glaze layer; the lower surface of which is provided with a first aerogel coating and a second aerogel coating from the inside to the outside, and a three-dimensional mesh air insulation structure is formed between the first aerogel coating and the second aerogel coating. The sunlight-reflecting glaze layer is made by firing sunlight-reflecting glaze. The raw materials for preparing the sunlight-reflecting glaze include, by weight: 40-60 parts tin oxide, 10-20 parts aluminum oxide, 5-15 parts calcium oxide, 5-15 parts magnesium oxide, 5-15 parts silicon oxide, 2-10 parts titanium oxide, 0.1-1 parts iron oxide, and 5-15 parts vanadium pentoxide. The first aerogel coating is formed by drying and curing a first aerogel coating. The raw material components of the first aerogel coating, by weight, include: 5-15 parts aerogel powder, 1-3 parts binder, and 6-10 parts diluent. The second aerogel coating is formed by drying and curing a second aerogel coating. The raw material components of the second aerogel coating are the same as those of the first aerogel coating. The raw material components of the aerogel powder, by weight, include: 5-15 parts sodium silicate, 3-8 parts aluminum silicate, 1-3 parts formaldehyde, and 0.5-1.5 parts sulfuric acid.

2. The composite lightweight ceramic brick according to claim 1, characterized in that, The thickness of the first aerogel coating and the second aerogel coating is 1-4 mm; and / or, the thickness of the lightweight ceramic brick substrate is 8-10 mm.

3. A method for preparing a composite lightweight ceramic brick as described in any one of claims 1 to 2, characterized in that, Includes the following steps: (1) Mix the raw materials for preparing lightweight ceramic brick substrate, make them into powder, press them into shape, and obtain lightweight ceramic brick blank; then apply sunlight-reflecting glaze to the upper surface of the lightweight ceramic brick blank, and fire it to obtain a lightweight ceramic brick substrate containing a sunlight-reflecting glaze layer. (2) The lower surface of the lightweight ceramic brick substrate obtained in step (1) is first coated with a first aerogel coating, dried and cured to form a first aerogel coating. Then, a second aerogel coating is applied to the lower surface of the first aerogel coating, dried and cured to form the second aerogel coating, thus obtaining the composite lightweight ceramic brick.

4. The method for preparing composite lightweight ceramic bricks according to claim 3, characterized in that, In step (1), the firing temperature is 1000-1100℃ and the firing time is 30-40min.

5. The method for preparing composite lightweight ceramic bricks according to claim 3, characterized in that, In step (2), the drying and curing temperature is 50-70℃, and the drying and curing time is 1-3 hours.

6. The application of the composite lightweight ceramic brick according to any one of claims 1 to 2 in building exterior walls.

Images