Thermal insulation travertine ceramic tile and preparation method thereof

Abstract

The invention relates to the technical field of ceramic tiles, and mainly relates to a heat preservation travertine ceramic tile and a preparation method thereof.The heat preservation travertine ceramic tile comprises a ceramic tile body and a nano coating, and the ceramic tile body comprises potassium albite, medium-temperature potassium sand, bentonite, brushstone, talcum powder, kaolin, raw slime, china clay, bauxite and aluminum oxide modified microcapsules; the preparation method of the aluminum oxide modified microcapsule comprises the following steps: heating paraffin to a molten state to obtain molten paraffin; the preparation method comprises the following steps: mixing a PVA aqueous solution with molten paraffin, and stirring at 7500-8500r / min to form a paraffin emulsion; dispersing nano aluminum oxide into the melamine-formaldehyde resin solution to obtain a suspension solution; mixing the suspension solution with a paraffin emulsion to obtain a mixed solution; adjusting the pH value of the mixed solution, and stirring and reacting at 60-70 DEG C for 2-3 hours to form a microcapsule wall; and cooling, separating, washing and drying to obtain the aluminum oxide modified microcapsule.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic tiles, and particularly relates to a thermal insulation hole stone ceramic tile and a preparation method thereof. BACKGROUND

[0002] Hole stone ceramic tiles have become popular materials in the field of building decoration due to their unique natural texture and stone-like quality. The surface of the hole stone ceramic tile presents a natural distribution of holes and mottled texture, which not only retains the rugged beauty of natural hole stone, but also optimizes the weather resistance and easy cleaning through ceramic process, and is widely used in indoor and outdoor wall surfaces, floors and landscape engineering. Especially in high-end commercial space and cultural buildings, the decorative effect of hole stone ceramic tile can significantly improve the artistic atmosphere and quality of space, and the market demand continues to grow.

[0003] Currently, the thermal insulation performance of hole stone ceramic tiles mainly depends on the external additional insulation layer, and common methods include pasting polystyrene board, rock wool board and other thermal insulation materials on the back of the tile. However, these technologies have significant defects: first, the bonding interface between the thermal insulation material and the ceramic tile is easily affected by temperature changes and moisture penetration, leading to a decrease in bonding strength, and a high risk of falling after long-term use, directly affecting the thermal insulation effect and the service life of the tile; second, some thermal insulation materials (such as closed-cell polystyrene board) can block the natural ventilation channels of the ceramic tile, causing indoor moisture accumulation and mold problems, and the thick insulation layer may cover the hole stone texture, weakening the decorative effect; more importantly, the density of traditional thermal insulation materials is generally high (such as the density of rock wool board is about 120 kg / m³), and the weight per square meter of a 100 mm thick insulation layer is about 12 kg, plus the weight of the hole stone ceramic tile itself (about 25 kg / m²), which will significantly increase the load of the building structure, posing a potential threat to the safety of high-rise buildings.

[0004] With the continuous improvement of global building energy-saving standards, traditional hole stone ceramic tiles have been unable to meet the comprehensive requirements of thermal performance for green buildings. According to statistics, building energy consumption accounts for more than 21% of total social energy consumption in China, and the heat loss through external walls accounts for as high as 40%. If hole stone ceramic tiles cannot be integrated with thermal insulation, it will force the building to add an additional insulation layer, which not only increases the cost of materials and construction, but also may cause safety accidents due to the falling of the insulation layer and the overloading of the structure. In particular, in cold regions, traditional insulation technology cannot meet the demand of super-low energy consumption buildings, resulting in high winter heating energy consumption, which is contrary to the goal of carbon neutralization.

[0005] Therefore, developing hole stone ceramic tiles with both decorative and high-efficiency thermal insulation performance has become a key technical direction for promoting the green transformation of the building industry. SUMMARY

[0006] In view of the shortcomings of the prior art, the purpose of this application is to provide a thermal insulation travertine ceramic brick and its preparation method. It aims to achieve an integrated design of the insulation layer and ceramic brick through material innovation and structural optimization, which can not only retain the natural beauty of the travertine texture, but also significantly improve the thermal performance of the building and reduce the structural load. It provides a safe, durable and comfortable solution for high-rise buildings and ultra-low energy consumption buildings, and has important strategic significance for promoting the upgrading of the building decoration materials industry.

[0007] The technical solution of this application is as follows: A thermal insulation travertine ceramic brick includes a ceramic brick body and a nano-coating, wherein the nano-coating is applied to the surface of the ceramic brick body. The ceramic brick body comprises the following raw materials by weight percentage: 30-40% potassium sodium feldspar, 10-15% medium-temperature potassium sand, 1-5% bentonite, 1-3% hygroscopic stone, 5-10% talc, 15-20% kaolin, 7-12% raw ore mud, 1-5% porcelain clay, 1-5% bauxite, and 1-5% alumina-modified microcapsules; The preparation method of the alumina-modified microcapsules includes the following steps: Step 1: Heat the paraffin wax to a molten state to obtain molten paraffin wax; Step 2: Mix a 1-5% (w / w) PVA aqueous solution with the molten paraffin wax and stir at 7500-8500 r / min for 15-45 min to form a paraffin wax emulsion; Step 3: Disperse nano-alumina in a melamine-formaldehyde resin solution to obtain a suspension; Step 4: Under stirring, the suspension solution is mixed with the paraffin emulsion to obtain a mixed solution; Step 5: Add hydrochloric acid solution to the mixed solution, adjust the pH value to 4-5, and stir the reaction at 60-70℃ for 2-3 hours to form microcapsule walls; Step 6: Cool, separate, wash, and dry to obtain the alumina-modified microcapsules.

[0008] Paraffin wax, as a typical phase change material, possesses advantages such as high latent heat of phase change, no supercooling phenomenon, and the ability to undergo phase change at ambient temperature. When formulated into microcapsules, it effectively prevents leakage after melting, enabling energy storage in buildings. When applied to ceramic tiles, when the ambient temperature rises, the paraffin wax microcapsules absorb heat and undergo a solid-liquid phase change, storing the heat. When the ambient temperature decreases, the paraffin wax microcapsules release the stored heat, maintaining a stable indoor temperature, reducing heat loss, and thus improving insulation.

[0009] During the firing process of ceramic tiles, high-temperature treatment (above 1000℃) is typically required. However, melamine-formaldehyde resin, used as the microcapsule wall material, has limited high-temperature resistance and is prone to decomposition or carbonization at high temperatures, leading to microcapsule rupture and paraffin leakage. Paraffin leakage not only reduces the thermal insulation performance of the ceramic tiles but also contaminates their surface, affecting their aesthetics. Furthermore, the gases produced by the decomposition of melamine-formaldehyde resin may pollute the environment. Therefore, improving the high-temperature resistance of the microcapsule wall material is crucial to ensuring both the thermal insulation performance and environmental friendliness of ceramic tiles.

[0010] Based on this, this application prepares special alumina-modified microcapsules. Nano-alumina possesses excellent high-temperature resistance and chemical stability, effectively improving the high-temperature resistance of the microcapsule wall material. Nano-alumina can fill the spaces between the molecular chains of melamine-formaldehyde resin, forming an interpenetrating network structure that enhances the strength and rigidity of the microcapsule wall material, preventing its decomposition or carbonization at high temperatures. Furthermore, nano-alumina can also chemically react with melamine-formaldehyde resin to form chemical bonds, improving the heat resistance and chemical corrosion resistance of the microcapsule wall material.

[0011] Furthermore, PVA, as an emulsifier, can reduce the surface tension of paraffin, promote emulsion formation, and improve the encapsulation efficiency of microcapsules. Melamine-formaldehyde resin has good film-forming properties and chemical stability, effectively protecting paraffin.

[0012] In this application, the synergistic effect of alumina-modified microcapsules and nano-coating effectively enhances the thermal insulation performance of travertine ceramic bricks. The alumina-modified microcapsules contain numerous nanopores, which effectively prevent heat transfer, forming a good insulation layer. Simultaneously, the nano-coating uniformly covers the surface of the microcapsules, further reducing heat loss. Its dense structure reduces air convection and heat conduction. Together, these two components construct a highly efficient thermal insulation system within the travertine ceramic brick, significantly reducing the heat conduction rate and giving the travertine ceramic brick excellent thermal insulation properties, making it widely applicable in fields requiring high thermal insulation.

[0013] Furthermore, in step 1, the paraffin wax is heated to a molten state, and the temperature is controlled at 60-70°C.

[0014] Furthermore, in step 4, the suspension is slowly added to the paraffin emulsion while being stirred.

[0015] Furthermore, in step 4, the suspension is added to the paraffin emulsion by dripping, with the dripping rate controlled at 3-6 mL / min.

[0016] Furthermore, in step 6, the mixture is cooled to room temperature, then centrifuged, washed multiple times with water, and then vacuum dried to obtain the alumina-modified microcapsules.

[0017] Furthermore, in step 6, the vacuum drying conditions are 55-65℃ for 18-36 hours.

[0018] Furthermore, the nano-coating is prepared by nano-coating, which comprises the following raw materials in parts by weight: 5-15 parts titanium dioxide, 2-6 parts silica sol, and 1-3 parts acrylic resin.

[0019] The titanium dioxide-containing nano-coating exhibits excellent air permeability and self-cleaning properties, preventing leakage of alumina-modified microcapsules and maintaining the air permeability of travertine ceramic tiles. Silica sol, acting as a binder, firmly bonds the titanium dioxide nanoparticles to the ceramic tile surface.

[0020] In this application, the effective combination of alumina-modified microcapsules and nano-coatings is utilized to synergistically solve the problems of high temperature resistance of microcapsule wall materials and durability of breathable nano-coatings.

[0021] Nano-alumina exhibits excellent high-temperature resistance and chemical stability. During microcapsule preparation, nano-alumina is uniformly dispersed in a melamine-formaldehyde resin solution. As the melamine-formaldehyde resin polymerizes to form the microcapsule wall, the nano-alumina embeds itself within the resin wall, forming an interpenetrating network structure. This structure enhances the strength and rigidity of the microcapsule wall, improving its high-temperature resistance. Simultaneously, the hydroxyl groups on the surface of the nano-alumina can chemically react with the melamine-formaldehyde resin to form chemical bonds, further improving the heat resistance and chemical corrosion resistance of the microcapsule wall.

[0022] In nano-coatings, acrylic resin, as an organic polymer, possesses excellent flexibility and weather resistance. The carboxyl groups in the acrylic resin can undergo esterification reactions with the hydroxyl groups on the surface of titanium dioxide nanoparticles and the silanol groups in silica sol, forming chemical bonds that firmly bind the organic polymer and inorganic nanoparticles together, creating an organic-inorganic hybrid network structure. This structure enhances the coating's adhesion strength and flexibility, improves its resistance to ultraviolet radiation, acid rain, and wind and sand, and prevents aging and peeling during long-term use.

[0023] Furthermore, the surface hydroxyl groups of the alumina-modified microcapsules can undergo condensation reactions with the carboxyl groups (-COOH) of the silica sol (Si-OH) or acrylic resin in the nanocoating, forming a chemically bonded interface. Simultaneously, the nanopores of the alumina-modified microcapsules can adsorb small organic molecules from the coating, further enhancing the binding force through physical anchoring. This structural complementarity enables the coating to form a dense encapsulation layer on the microcapsule surface, significantly improving interfacial stability.

[0024] The nanopores of alumina-modified microcapsules serve as gas transport channels, maintaining the coating's permeability; simultaneously, the alumina on their surface blocks the penetration of corrosive media (such as water and chloride ions). Within the nanocoating, the inorganic network formed by titanium dioxide and silica sol is further densified, inhibiting the intrusion of large molecular corrosive media; the hydrophobicity of the acrylic resin reduces the coating's surface energy, minimizing moisture adsorption. The permeable channels of the alumina-modified microcapsules and the dense barrier of the nanocoating form a "selective penetration" mechanism, effectively improving corrosion resistance while maintaining permeability.

[0025] Furthermore, the alumina-modified microcapsules, as flexible fillers, are dispersed in the coating. When the coating is subjected to external force, the alumina-modified microcapsules absorb energy through elastic deformation, preventing crack propagation.

[0026] Furthermore, the thickness of the nano-coating is 40-60 μm.

[0027] This application also provides a method for preparing heat-insulating travertine ceramic bricks, comprising the following steps: Step a: Mix the potassium-sodium feldspar, the medium-temperature potassium sand, the bentonite, the siliceous limestone, the talc powder, the kaolin, the raw ore mud, the porcelain clay, the bauxite, and the alumina-modified microcapsules to obtain the glaze; Step b: Using a cloth-feeding device, the glaze is applied along the extension direction of multiple sets of pits and / or bumps, and then pressed into shape to obtain a brick blank with longitudinal texture, pits and / or bumps on the surface. Step c: Fire the brick blank, trim and polish the edges to obtain the ceramic brick body; Step d: Preparation of the nano-coating: The titanium dioxide, the silica sol, and the acrylic resin are mixed and dispersed evenly to obtain the nano-coating; Step e: Spray the nano-coating onto the surface of the ceramic tile body; Step f: The ceramic brick body coated with the nano-coating is dried at 175-185°C, and the nano-coating is formed to obtain the heat-insulating travertine ceramic brick.

[0028] Furthermore, in step b, the pressing pressure is 42000-45000KN; in step c, the firing temperature is 1150-1250℃.

[0029] Compared with the prior art, this application has the following beneficial effects: 1. By combining alumina-modified microcapsules with a nano-coating, the stability of material properties is significantly improved. Nano-alumina is embedded in the microcapsule wall to form an interpenetrating network structure, enhancing the wall's strength and stiffness, and improving high-temperature resistance and chemical corrosion resistance. In the nano-coating, acrylic resin and inorganic nanoparticles form an organic-inorganic hybrid network structure, enhancing bonding strength and flexibility, improving resistance to ultraviolet radiation, and preventing aging and detachment. The synergy of these two components effectively improves interfacial stability, enabling thermal insulation travertine ceramic bricks to maintain stable performance over long periods in complex environments.

[0030] 2. This application effectively enhances the corrosion resistance of thermally insulated travertine ceramic bricks. The nanopores of the alumina-modified microcapsules maintain the air permeability of the coating, while the alumina on the surface blocks the penetration of corrosive media. In the nano-coating, titanium dioxide and silica sol form a dense inorganic network, inhibiting the intrusion of large molecular corrosive media, while the hydrophobicity of the acrylic resin reduces surface energy and decreases moisture adsorption. These two elements form a "selective penetration" mechanism, maintaining air permeability while blocking corrosive media, greatly improving the material's corrosion resistance and extending its service life.

[0031] 3. The synergistic effect of alumina-modified microcapsules and nano-coatings significantly enhances the thermal insulation performance of travertine ceramic bricks. The numerous nanopores within the microcapsules effectively prevent heat transfer, forming an insulating layer; the nano-coating uniformly covers its surface, and its dense structure reduces air convection and heat conduction. Together, these two elements construct a highly efficient thermal insulation system within the travertine ceramic brick, drastically reducing the rate of heat conduction and giving the travertine ceramic brick excellent thermal insulation properties, making it widely applicable in fields requiring thermal insulation. Detailed Implementation

[0032] To facilitate understanding of this application, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of this application.

[0033] This application provides a heat-insulating travertine ceramic brick, including a ceramic brick body and a nano-coating, wherein the nano-coating is applied to the surface of the ceramic brick body. The ceramic tile body comprises the following raw materials by weight percentage: 30-40% potassium and sodium feldspar, 10-15% medium-temperature potassium sand, 1-5% bentonite, 1-3% hygroscopic limestone, 5-10% talc, 15-20% kaolin, 7-12% raw ore mud, 1-5% porcelain clay, 1-5% bauxite, and 1-5% alumina-modified microcapsules.

[0034] The preparation method of alumina-modified microcapsules includes the following steps: Step 1: Heat the paraffin wax to a molten state, controlling the temperature at 60-70℃, to ensure that the paraffin wax is completely melted, thus obtaining molten paraffin wax.

[0035] Step 2: Dissolve PVA in water to prepare a PVA aqueous solution with a concentration of 1-5 wt%.

[0036] Slowly add the PVA aqueous solution to the molten paraffin and stir it for 15-45 minutes using a high-speed disperser at a speed of 7500-8000 rpm to form a paraffin emulsion.

[0037] Step 3: Add melamine-formaldehyde resin to an appropriate amount of water to prepare a melamine-formaldehyde resin solution with a concentration of 5-15wt%, stir well and set aside.

[0038] Nano-alumina was dispersed in a melamine-formaldehyde resin solution and ultrasonically dispersed for 15-45 minutes using an ultrasonic disperser to ensure uniform dispersion of the nano-alumina; a suspension was obtained.

[0039] Step 4: While stirring, slowly add the suspension to the paraffin emulsion by dropping, controlling the dropping rate at 3-6 mL / min; to obtain a mixed solution.

[0040] Step 5: Add a 1 mol / L hydrochloric acid solution to the mixed solution, adjust the pH to 4-5, continue stirring for 2-3 hours, and maintain the reaction temperature at 60-70℃ to allow the melamine-formaldehyde resin to polymerize on the surface of the paraffin emulsion. At the same time, nano-alumina is embedded in the melamine-formaldehyde resin wall to form a microcapsule wall.

[0041] Step 6: Cool the material obtained in Step 5 to room temperature, and centrifuge it at 4000 rpm for 10 minutes to separate the microcapsules.

[0042] Step 7: Wash the microcapsules three times with deionized water, and centrifuge after each wash.

[0043] Step 8: Place the washed microcapsules in a vacuum drying oven and dry them at 55-65℃ for 18-36 hours to obtain alumina-modified microcapsules.

[0044] The nano-coating is prepared by nano-coating and has a thickness of 40-60 μm.

[0045] The nano-coating comprises the following raw materials in parts by weight: 5-15 parts titanium dioxide, 2-6 parts silica sol, and 1-3 parts acrylic resin.

[0046] This application also provides a method for preparing thermally insulating travertine ceramic bricks, including the following steps: Step a: Mix potassium-sodium feldspar, medium-temperature potassium sand, bentonite, hygroscopic limestone, talc powder, kaolin, raw ore mud, porcelain clay, bauxite, and alumina-modified microcapsules. Use a ball mill to ball mill the mixture for 2 hours to obtain the glaze.

[0047] Step b: Using a cloth-feeding device, the glaze is applied along the extension direction of multiple sets of pits and / or protrusions in the mold, and then pressed into shape to obtain a brick blank with longitudinal texture, pits and / or protrusions on the surface.

[0048] The pressing pressure is 42000-45000KN.

[0049] Step c: Place the brick blank in the kiln for firing, trim and polish the edges to obtain the ceramic brick body.

[0050] The firing temperature is 1150-1250℃.

[0051] Step d: Preparation of nano-coatings: First, mix titanium dioxide and silica sol according to the specified ratio and stir with a magnetic stirrer for 10 minutes to make them initially uniform; then add acrylic resin and continue stirring for 20 minutes to ensure that the three raw materials are fully mixed.

[0052] Then disperse the nano-coating using an ultrasonic disperser for 15-45 minutes.

[0053] Step e: Use a spraying device to spray the nano-coating onto the surface of the ceramic tile.

[0054] Step f: Dry the ceramic brick body coated with nano-coating at 175-185℃ for 1-2 hours to form the nano-coating and obtain the heat-insulating travertine ceramic brick.

[0055] The present application will be further described below through specific embodiments.

[0056] Example 1 A thermal insulation travertine ceramic brick includes a ceramic brick body and a nano-coating, wherein the nano-coating is applied to the surface of the ceramic brick body. The ceramic tile body comprises the following raw materials by weight percentage: 37.5% potassium sodium feldspar, 12% medium-temperature potassium sand, 4% bentonite, 1.5% siliceous limestone, 7% talc, 19% kaolin, 10% raw ore mud, 3% porcelain clay, 2.5% bauxite, and 3.5% alumina modified microcapsules.

[0057] The preparation method of alumina-modified microcapsules includes the following steps: Step 1: Heat the paraffin wax to a molten state, controlling the temperature at 65℃ to ensure that the paraffin wax is completely melted, thus obtaining molten paraffin wax.

[0058] Step 2: Dissolve PVA (purchased from Chengdu Blue Whale Technology Co., Ltd., model 9002) in water to prepare a PVA aqueous solution with a concentration of 3wt%.

[0059] The PVA aqueous solution was slowly added to the molten paraffin and stirred for 30 minutes at 8000 rpm using a high-speed disperser to form a paraffin emulsion.

[0060] Step 3: Add melamine-formaldehyde resin (purchased from Nantong Zhonghe Chemical New Materials Co., Ltd.) to an appropriate amount of water to prepare a melamine-formaldehyde resin solution with a concentration of 10wt%, stir well and set aside.

[0061] Nano-alumina (particle size 20-30nm) was dispersed in a melamine-formaldehyde resin solution and ultrasonically dispersed for 30 minutes using an ultrasonic disperser to ensure uniform dispersion of the nano-alumina; a suspension was obtained.

[0062] Step 4: While stirring, slowly add the suspension to the paraffin emulsion by dropping it at a rate of 5 mL / min to obtain a mixed solution.

[0063] Step 5: Add a 1 mol / L hydrochloric acid solution to the mixed solution, adjust the pH to 4.5, continue stirring for 2 hours, and maintain the reaction temperature at 65℃ to allow the melamine-formaldehyde resin to polymerize on the surface of the paraffin emulsion. At the same time, nano-alumina is embedded in the melamine-formaldehyde resin wall to form a microcapsule wall.

[0064] Step 6: Cool the material obtained in Step 5 to room temperature, and centrifuge it at 4000 rpm for 10 minutes to separate the microcapsules.

[0065] Step 7: Wash the microcapsules three times with deionized water, and centrifuge after each wash.

[0066] Step 8: Place the washed microcapsules in a vacuum drying oven and dry them at 60°C for 24 hours to obtain alumina-modified microcapsules.

[0067] The nano-coating is prepared by nano-coating and has a thickness of 50 μm.

[0068] The nano-coating comprises the following raw materials in parts by weight: 10 kg titanium dioxide, 5 kg silica sol, and 2 kg acrylic resin.

[0069] The titanium dioxide is anatase titanium dioxide with a particle size of 20-30 nm.

[0070] The acrylic resin was purchased from Shengwanjia New Materials (Shandong) Co., Ltd.

[0071] The silica sol was purchased from Guangdong Kening Technology Co., Ltd., model number J30.

[0072] This application also provides a method for preparing thermally insulating travertine ceramic bricks, including the following steps: Step a: Mix potassium-sodium feldspar, medium-temperature potassium sand, bentonite, hygroscopic limestone, talc powder, kaolin, raw ore mud, porcelain clay, bauxite, and alumina-modified microcapsules. Use a ball mill to ball mill the mixture for 2 hours to obtain the glaze.

[0073] Step b: Using a cloth-feeding device, the glaze is applied along the extension direction of multiple sets of pits and / or protrusions in the mold, and then pressed into shape to obtain a brick blank with longitudinal texture, pits and / or protrusions on the surface.

[0074] The pressing pressure is 43000KN.

[0075] Step c: Place the brick blank in the kiln for firing, trim and polish the edges to obtain the ceramic brick body.

[0076] The firing temperature is 1200℃.

[0077] Step d: Preparation of nano-coatings: First, mix titanium dioxide and silica sol according to the specified ratio and stir with a magnetic stirrer for 10 minutes to make them initially uniform; then add acrylic resin and continue stirring for 20 minutes to ensure that the three raw materials are fully mixed.

[0078] The nano-coating was then dispersed for 30 minutes using an ultrasonic disperser.

[0079] Step e: Use a spraying device to spray the nano-coating onto the surface of the ceramic tile.

[0080] Step f: Dry the ceramic brick body coated with nano-coating at 180℃ for 2 hours to form the nano-coating and obtain the heat-insulating travertine ceramic brick.

[0081] Performance testing: 1. High-temperature resistance test of alumina-modified microcapsules: Alumina-modified microcapsules were placed in a muffle furnace and calcined at 1200℃ for 30 minutes. The morphology of the microcapsules was then observed using a scanning electron microscope (SEM), and the rupture rate of the microcapsules was calculated.

[0082] 2. Weather resistance test of ceramic tiles: The test was conducted in accordance with GB / T 16422.3-2014 "Laboratory Light Source Exposure Test Method for Plastics - Part 3: Fluorescent Ultraviolet Lamp", with an ultraviolet intensity of 0.89 W / (m2·nm) and a test time of 1000 hours. The appearance changes of the coating were then observed, and the adhesion of the coating was tested using the cross-cut test.

[0083] 3. Thermal conductivity test of ceramic tiles: The test shall be conducted in accordance with GB / T 10295-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials by heat flow meter method" and the test temperature shall be 25℃.

[0084] 4. Flexural strength test of ceramic tiles: The test shall be conducted in accordance with GB / T 3810.4-2016 "Test methods for ceramic tiles - Part 4: Determination of modulus of rupture and breaking strength".

[0085] Test results: 1. Microcapsule rupture rate: 5%.

[0086] 2. Coating weather resistance: No significant change, adhesion is grade 1.

[0087] 3. Thermal conductivity: 0.43 W / (m·K).

[0088] 4. Flexural strength: 37 MPa.

[0089] Comparative Example 1 Choose a common brand of travertine ceramic tiles on the market (without any added insulation material, hereinafter referred to as "control tiles").

[0090] The performance of the control brick was tested using the same method as in Example 1.

[0091] Test results: Thermal conductivity: 1.2 W / (m·K).

[0092] Flexural strength: 35 MPa.

[0093] Comparative Example 2 A thermal insulation travertine ceramic brick differs from Example 1 in that it omits the nano-coating.

[0094] Thermal conductivity: 0.68 W / (m·K).

[0095] Flexural strength: 33.5 MPa.

[0096] Comparative Example 3 A thermal insulation travertine ceramic brick differs from Example 1 in that, in the preparation method of alumina-modified microcapsules, PVA is replaced with sodium maleic anhydride-styrene copolymer, which was purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.

[0097] Microcapsule rupture rate: 10%.

[0098] Coating weather resistance: varies, adhesion is level 2.

[0099] Thermal conductivity: 0.77 W / (m·K).

[0100] Flexural strength: 36.1 MPa.

[0101] Comparative Example 4 A thermal insulation travertine ceramic brick differs from Example 1 in that, in the preparation method of alumina modified microcapsules, step 2 involves slowly adding a PVA aqueous solution to molten paraffin and stirring at 1000 rpm for 30 minutes to form a paraffin emulsion.

[0102] Microcapsule rupture rate: 8%.

[0103] Coating weather resistance: varies, adhesion is level 2.

[0104] Thermal conductivity: 0.83 W / (m·K).

[0105] Flexural strength: 35.8 MPa.

[0106] According to the test data, the heat-insulating travertine ceramic brick prepared in Example 1 has a significant improvement in heat insulation compared with Comparative Example 1, and its flexural strength is also higher. This shows that the technical solution provided in this application can give the heat-insulating travertine ceramic brick good heat insulation effect and excellent mechanical properties.

[0107] Comparative Example 2, based on Example 1, omitted the nano-coating, thus losing the protection of the nano-coating and the special synergy between the nano-coating and the alumina-modified microcapsules. As a result, Comparative Example 2 showed a significant decline in performance in terms of heat preservation, mechanical properties, and other aspects.

[0108] Comparative Examples 3 and 4, based on Example 1, involved replacing key substances or altering key mixing methods. The resulting microcapsules exhibited significantly higher rupture rates and decreased thermal insulation and mechanical properties compared to Example 1. This demonstrates that the technical solution provided in this application is a complete whole and cannot be arbitrarily altered.

[0109] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of this application.

Claims

1. A type of heat-insulating travertine ceramic brick, characterized in that, It includes a ceramic tile body and a nano-coating, wherein the nano-coating is applied to the surface of the ceramic tile body. The ceramic brick body comprises the following raw materials by weight percentage: 30-40% potassium sodium feldspar, 10-15% medium-temperature potassium sand, 1-5% bentonite, 1-3% hygroscopic stone, 5-10% talc, 15-20% kaolin, 7-12% raw ore mud, 1-5% porcelain clay, 1-5% bauxite, and 1-5% alumina-modified microcapsules; The preparation method of the alumina-modified microcapsules includes the following steps: Step 1: Heat the paraffin wax to a molten state to obtain molten paraffin wax; Step 2: Mix a 1-5% (w / w) PVA aqueous solution with the molten paraffin wax and stir at 7500-8500 r / min for 15-45 min to form a paraffin wax emulsion; Step 3: Disperse nano-alumina in a melamine-formaldehyde resin solution to obtain a suspension; Step 4: Under stirring, the suspension solution is mixed with the paraffin emulsion to obtain a mixed solution; Step 5: Add hydrochloric acid solution to the mixed solution, adjust the pH value to 4-5, and stir the reaction at 60-70℃ for 2-3 hours to form microcapsule walls; Step 6: Cool, separate, wash, and dry to obtain the alumina-modified microcapsules.

2. The thermal insulation travertine ceramic brick according to claim 1, characterized in that, In step 1, the paraffin wax is heated to a molten state, and the temperature is controlled at 60-70℃.

3. The thermal insulation travertine ceramic brick according to claim 1, characterized in that, In step 4, the suspension is slowly added to the paraffin emulsion while stirring.

4. The heat-insulating travertine ceramic brick according to claim 3, characterized in that, In step 4, the suspension is added to the paraffin emulsion by dropping, and the dropping rate is controlled to be 3-6 mL / min.

5. The thermal insulation travertine ceramic brick according to claim 1, characterized in that, In step 6, the mixture is cooled to room temperature, then centrifuged, washed multiple times with water, and then vacuum dried to obtain the alumina-modified microcapsules.

6. The thermal insulation travertine ceramic brick according to claim 5, characterized in that, In step 6, the vacuum drying conditions are 55-65℃ for 18-36 hours.

7. The thermal insulation travertine ceramic brick according to claim 1, characterized in that, The nano-coating is prepared by nano-coating, which includes the following raw materials in parts by weight: 5-15 parts titanium dioxide, 2-6 parts silica sol, and 1-3 parts acrylic resin.

8. The thermal insulation travertine ceramic brick according to claim 1, characterized in that, The thickness of the nano-coating is 40-60 μm.

9. A method for preparing thermally insulating travertine ceramic bricks according to any one of claims 1-8, characterized in that, Includes the following steps: Step a: Mix the potassium-sodium feldspar, the medium-temperature potassium sand, the bentonite, the siliceous limestone, the talc powder, the kaolin, the raw ore mud, the porcelain clay, the bauxite, and the alumina-modified microcapsules to obtain the glaze; Step b: Using a cloth-feeding device, the glaze is applied along the extension direction of multiple sets of pits and / or bumps, and then pressed into shape to obtain a brick blank with longitudinal texture, pits and / or bumps on the surface. Step c: Fire the brick blank, trim and polish the edges to obtain the ceramic brick body; Step d: Preparation of the nano-coating: The titanium dioxide, the silica sol, and the acrylic resin are mixed and dispersed evenly to obtain the nano-coating; Step e: Spray the nano-coating onto the surface of the ceramic tile body; Step f: The ceramic brick body coated with the nano-coating is dried at 175-185°C, and the nano-coating is formed to obtain the heat-insulating travertine ceramic brick.

10. The method for preparing thermally insulating travertine ceramic bricks according to claim 9, characterized in that, In step b, the pressing pressure is 42000-45000KN; in step c, the firing temperature is 1150-1250℃.