Wall thermal insulation material and preparation method thereof

Abstract

The invention relates to the technical field of preparation of wall thermal insulation materials, and particularly discloses a wall thermal insulation material and a preparation method thereof. 5-8 parts of silicon dioxide sol; 6 to 10 parts of aerogel microspheres; 6-10 parts of a phase change microcapsule; 12 to 15 parts of expanded perlite or light expanded aggregate; 12-15 parts of active fly ash or high-activity slag; 6-10 parts of Portland cement; 0.4 to 0.8 part of polypropylene chopped fiber; 0.5 to 0.8 part of a silane coupling agent; 0.6-1 part of a closed pore nucleating agent and a template; 0.3 to 0.5 part of a multifunctional water reducing agent; the excitation liquid and the water are used for excitation and forming, and the ratio of the excitation liquid to the activated attapulgite is 1: (0.18-0.22); the micro / nano-scale aerogel skeleton, the closed-pore multi-scale porous structure and the phase-change microcapsule are organically coupled to form a collaborative network of multiple heat-resistant mechanisms, so that the heat-resistant phase-change microcapsule plays a role in two aspects of steady-state heat transfer and transient thermal shock at the same time.

Description

Technical Field

[0001] This invention belongs to the field of wall insulation and heat insulation material preparation technology, specifically relating to a wall insulation and heat insulation material and its preparation method. Background Technology

[0002] Driven by the dual demands of building energy conservation and green development, performance optimization of wall insulation materials has become a key research direction. However, existing technologies consistently face the bottleneck of balancing multiple performance characteristics, mainly in the following aspects:

[0003] Traditional organic insulation materials such as polystyrene (EPS) and extruded polystyrene (XPS) have low thermal conductivity (0.028–0.041 W / (m·K)), but they suffer from poor fire safety (mostly B2 fire rating), release of toxic gases at high temperatures, and performance degradation due to long-term aging. Furthermore, their petroleum-based raw material production process emits carbon emissions as high as 3.4 kg CO2 eq / kg, contradicting the concept of low-carbon development. Inorganic insulation materials such as rock wool boards meet Class A fire resistance requirements, but their thermal conductivity is relatively high (0.039–0.044 W / (m·K)) and they are heavy (120–180 kg / m²). 3 It has a high water absorption rate (≥5%), and its thermal insulation performance drops sharply after getting damp. At the same time, the problem of fiber scattering increases the health risks during construction.

[0004] In response to this, this application proposes a wall insulation material and its preparation method to solve the above-mentioned problems. Summary of the Invention

[0005] The purpose of this invention is to provide a wall insulation material and its preparation method to solve the problems mentioned in the background art.

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

[0007] A wall insulation material, comprising, by weight parts:

[0008] Activated attapulgite clay 50-55 parts; silica sol (based on SiO2 solid content) 5-8 parts; aerogel microspheres 6-10 parts; phase change microcapsules 6-10 parts; expanded perlite or lightweight expanded aggregate 12-15 parts; activated fly ash or highly active slag 12-15 parts; silicate cement 6-10 parts; polypropylene chopped short fibers 0.4-0.8 parts; silane coupling agent 0.5-0.8 parts; closed-cell nucleating agent / template 0.6-1 parts; multifunctional water-reducing agent 0.3-0.5 parts;

[0009] The activated attapulgite clay is prepared with an activation solution (a mixture of alkaline activator and water glass) and water, wherein the activation solution and the activated attapulgite clay are mixed in a solid-liquid ratio of 1:0.18–0.22.

[0010] Preferably, the phase change microcapsules are paraffin or fatty acid-based phase change cores, polymers, or silica shells, with a particle size of 10–50 μm.

[0011] A method for preparing a wall thermal insulation material includes the following steps:

[0012] S1. The original attapulgite soil is dried and crushed to remove free water and refine the particle size, resulting in dry fine powder;

[0013] S2. The dried fine powder is washed with deionized water (with low-concentration acid washing if necessary) and then dried and calcined to remove soluble impurities and expand the pore structure to obtain activated attapulgite powder.

[0014] S3. The activated attapulgite powder is mixed with silica sol and then ultrasonically / high-shear dispersed and low-temperature gelled to form a nano-SiO2 framework in situ within the pores of the attapulgite and seal the pores to obtain nano-silica framework-attapulgite composite powder.

[0015] S4. The nano-silica framework-attapulgite composite powder is dry-mixed and homogenized with aerogel microspheres, expanded perlite, phase change microcapsules, fiber, silane coupling agent and closed-cell nucleating agent according to the formula to obtain homogeneous heat buffer composite dry powder.

[0016] S5. Mix the homogeneous thermal buffer composite dry powder with the activating liquid (alkaline solution and water glass) and adjust the rheology to obtain a castable slurry, thus obtaining a castable composite slurry;

[0017] S6. The castable composite slurry is poured into a mold and then cured, maintained, and surface-functionalized to form a closed-cell structure through chemical foaming or template method, resulting in a finished board.

[0018] The silica sol was prepared by alcohol-water-acid catalytic hydrolysis of TEOS, with a molar ratio of TEOS:EtOH:H2O of 1:4:4 and an acid (HCl) catalytic amount of 0.001–0.01 mol.

[0019] Preferably, the calcination temperature in step S2 is 350–450℃, and the holding time is 1.5–3h; the low-temperature gelation drying temperature in step S3 is <90℃.

[0020] Preferably, the activating liquid in step S5 is a mixture of NaOH solution (6–10M) and water glass in the required ratio, with the solid:liquid ratio controlled at 1:0.18–0.22, and the slump of the slurry adjusted to 50–80 mm.

[0021] Preferably, in step S6, when chemical foaming is used, the foaming agent is hydrogen peroxide or other controllable oxidizing foaming agent, and the amount used is 0.3–1.0 wt% of the total amount of homogeneous heat buffer composite dry powder; or when template method is used, the template is combustible or soluble microspheres with a template particle size of 0.1–2 mm.

[0022] Preferably, the finished board material has one or more of the following properties: bulk density ≤ 500 kg / m³ 3 Thermal conductivity 0.025–0.06 W / (m·K); water absorption ≤15%; compressive strength ≥0.5 MPa (or ≥1.5 MPa according to the implementation variant).

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) This invention organically couples a micro / nanoscale aerogel framework, a closed-pore multi-scale porous structure, and phase change microcapsules to form a synergistic network of multiple heat-resistant mechanisms, thereby simultaneously playing a role in both steady-state heat transfer and transient thermal shock. The in-situ formed silica nanoframework is nested with the loose porous matrix, interrupting the continuous solid-state heat conduction chain and introducing a large number of interfaces and defects at the nanoscale. The scattering effect of phonons by the interfaces and nanonetwork is significantly enhanced, thereby inhibiting the heat conduction of the solid phase. The large number of closed pores in the material confines the internal gas, reduces the free molecule transport efficiency, and triggers the pore size-related thermal resistance effect (reducing the heat conduction contribution of the gas phase), thus significantly improving the overall thermal resistance.

[0025] (2) This invention ensures excellent thermal insulation performance while balancing mechanical properties and durability through material composition and microstructure design, thereby guaranteeing long-term functional retention and engineering compatibility. The silica nanoframework forms a connected or semi-connected rigid network within the pores, physically nesting and chemically bonding with the geopolymer / small amount of cement-based binder system. Through interface modification measures such as coupling agents, the adhesion between the nanonetwork and the matrix is ​​enhanced, making it difficult for microcracks to initiate and effectively dispersing stress under macroscopic stress, thereby improving the material's crack resistance and compressive strength. Attached Figure Description

[0026] Figure 1 This is a flowchart of a method for preparing a wall insulation material according to the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1:

[0029] Please see Figure 1 As shown, a wall insulation material includes:

[0030] Formula (based on a total amount of activated attapulgite clay = 100 parts);

[0031] 50 parts of activated attapulgite;

[0032] 5 parts of silica sol (based on SiO2 solid content);

[0033] 6 parts of dry aerogel microspheres;

[0034] 6 parts of phase change microcapsules (PCM, dry);

[0035] 12 parts expanded perlite (or lightweight expanded aggregate);

[0036] 12 parts of active fly ash (or highly active slag);

[0037] Six parts of silicate cement (early strength);

[0038] 0.4 parts of chopped polypropylene fibers;

[0039] 0.5 parts of silane coupling agent (dry basis);

[0040] 0.6 parts of closed-cell nucleating agent / template (flammable or soluble);

[0041] Multifunctional water-reducing agent (solid content) 0.3 parts;

[0042] Activation solution / water (based on 100 parts of activated attapulgite): solid:liquid ≈ 1:0.20, where NaOH is equivalent to 6–8M ratio + water glass for activation (total liquid is about 20 parts). Adjust the water volume to make the slump of the slurry 50–80 mm (for pouring fluidity).

[0043] A method for preparing a wall insulation material includes:

[0044] Drying and crushing: The raw attapulgite clay was dried at 105℃ for 4 hours to remove free water and facilitate crushing. It was then ball-milled to an average particle size of 30–60 μm to obtain dry fine powder.

[0045] Cleaning / Acid Washing and Activation Calcination: Mix the dried fine powder with deionized water at a solid:liquid ratio of 1:4 and stir for 30–50 min (add 0.5–2 wt% dilute hydrochloric acid if necessary to remove carbonates). Allow the powder to settle, discard the supernatant, and dry. Then, heat the powder at 400℃ (take the middle value, range 350–450℃) for 2 h to remove impurities and expand the pores, thus obtaining activated attapulgite powder.

[0046] In-situ sol adsorption and low-temperature gelation: Activated attapulgite powder and silica sol (obtained from TEOS hydrolysis, TEOS:EtOH:H2O≈1:4:4) were mixed with 5 parts SiO2 solid content. The sol was stirred by ultrasonication or high shear (4000 rpm, 10–15 min) to allow the sol to enter the pores. The mixture was then dried at low temperature (≤90℃) to gel the sol, resulting in nano-silica framework-attapulgite composite powder (nano-SiO2 framework-attapulgite composite powder).

[0047] Dry-mixed low thermal conductivity / thermal buffer components: Nano-silica framework-attapulgite composite powder is dry-mixed with aerogel microspheres, expanded perlite, phase change microcapsules, polypropylene short-cut fibers, silane coupling agent, closed-cell nucleating agent and water-reducing agent according to the formula and homogenized under high shear to obtain homogeneous composite activated attapulgite.

[0048] Preparation of activation solution and slurry: Mix homogeneous composite activated attapulgite soil with activation solution (NaOH 6–8M + water glass) and add water to adjust (solid:liquid ≈ 1: 0.20). Under stirring conditions, adjust to a slump of 50–80 mm to obtain a castable composite slurry.

[0049] Injection molding, closed-cell formation, curing, and surface treatment: The castable composite slurry is injected into a 300×300×50mm mold (the surface layer with a 5–10mm thick adhesive layer can be poured first, followed by the core layer and then the surface layer to form a skin-core-skin structure). Chemical foaming (0.5wt% hydrogen peroxide) is used to achieve closed-cell formation (or template method). Initial curing is carried out at room temperature / 40–60℃ for 6–12 hours, followed by steam curing at 60–80℃ for 6 hours. The material is then dried in sections until the moisture content is ≤8–10%. Finally, a silane hydrophobic agent is sprayed onto the surface, followed by a thin high-reflection coating to obtain the finished board.

[0050] As can be seen from the above, this invention organically couples micro / nanoscale aerogel frameworks, closed-pore multi-scale porous structures, and phase change microcapsules to form a synergistic network of multiple heat-resistant mechanisms, thereby simultaneously playing a role in both steady-state heat transfer and transient thermal shock.

[0051] Solid-phase thermal conductivity path disruption and enhanced phonon scattering: The in-situ formed silica nanoframework nested within a loose porous matrix disrupts the continuous solid-state thermal conductivity pathways and introduces numerous interfaces and defects at the nanoscale. These interfaces and nanonetworks significantly enhance phonon scattering, thereby suppressing thermal conduction in the solid phase.

[0052] Limitations of gas thermal conductivity and pore size-related effects: A large number of closed pores in the material confine the internal gas, reducing the transport efficiency of free molecules and triggering pore size-related thermal resistance effects (reducing the contribution of gas phase thermal conductivity), thus significantly increasing the overall thermal resistance.

[0053] Radiation and convection heat transfer suppression: The graded aperture and layered structure simultaneously reduce the convection loops within the aperture and decrease the effective transmission channels for internal radiation; the high-reflectivity coating on the surface further reduces the absorption of incident radiation energy, thereby reducing the heat flux input caused by long-term sunlight or short-term irradiation.

[0054] Transient buffering of phase change heat absorption and release: When the temperature crosses the phase change temperature range, the dispersed encapsulated phase change microcapsules absorb or release latent heat. Coupled with the above-mentioned steady-state suppression mechanism, it not only reduces short-term temperature peaks, but also increases the hysteresis of thermal response, making the indoor / back side temperature change more gradual.

[0055] Example 2:

[0056] Increase PCM and aerogel;

[0057] 48 parts of activated attapulgite;

[0058] 5 parts of silica sol (based on SiO2 solid content);

[0059] 10 parts of dry aerogel microspheres (to improve low thermal conductivity);

[0060] 8 parts of phase change microcapsules (PCM, dry) (with increased heat buffer);

[0061] 10 parts expanded perlite;

[0062] 12 parts of activated fly ash;

[0063] 4 parts silicate cement (reduce cement content to reduce carbon content while retaining sufficient strength);

[0064] The fiber, coupling agent, closed-cell template, and water-reducing agent are adjusted slightly in the same proportion (0.4 parts fiber, 0.6 parts coupling agent, 0.6 parts template, and 0.3 parts water-reducing agent).

[0065] Activating solution / water ratio: solid:liquid ≈ 1:0.20;

[0066] Preparation method:

[0067] The steps are basically the same as in Example 1, except for the dry mixing ratio in step S4 and the closed-cell control in step S6 (using chemical foaming and strict foam control to achieve a higher closed-cell rate, with a target total porosity of 50%–60%). The final product is a high-performance finished board.

[0068] Comparative example: using conventional perlite-cement insulation board;

[0069] Thickness: 50mm

[0070] The materials of Example 1, Example 2, and the comparative example were tested, and the process is as follows:

[0071] Thermal conductivity test specimen: 300×300×50mm plate specimen, steady-state hot plate method (ASTM C518 equivalent), average of 3 specimens.

[0072] Compression test specimen: 50×50×50mm square or cut according to standard, compression rate 1mm / min, average of 5 specimens.

[0073] Water absorption rate: determined by mass ratio after soaking in water for 24 hours (or by vacuum water absorption method).

[0074] Phase change heat buffer (day and night cycle) test: The test sample (300×300×50mm) was placed in an environmental chamber, and the outdoor temperature simulated day and night: 10℃ at night (12h) → 40℃ during the day (12h). Thermocouples were set inside (back side of the board / inner surface) to record every 1 minute for 48 hours. The reference sample was a conventional perlite-cement board (comparative sample).

[0075] Experimental data;

[0076] Test results of Example 1:

[0077] All samples were 50 mm thick; the values ​​are averages, with a deviation within ±5%.

[0078] Thermal conductivity k = 0.048 W / (m·K);

[0079] Bulk density = 420 kg / m³ 3 →mass / m 2 =420 × 0.05 = 21.0 kg / m 2 ;

[0080] Compressive strength (static load) = 0.95 MPa (average);

[0081] Water absorption rate (24h) = 9.0% (by mass);

[0082] Phase change thermal buffer (peak temperature decrease) = peak temperature decrease of approximately 2.4℃ compared to the comparative sample.

[0083] The test data for Example 2 are as follows:

[0084] Thermal conductivity k = 0.032 W / (m·K);

[0085] Bulk density = 380 kg / m³ 3 →mass / m 2 =380 × 0.05 = 19.0 kg / m 2 ;

[0086] Compressive strength = 0.85 MPa (average);

[0087] Water absorption rate (24h) = 8.0%;

[0088] Phase change thermal buffer (peak temperature decrease) = peak temperature decrease of approximately 3.2℃ compared to the comparative sample;

[0089] Comparative test results:

[0090] Test results (average value, representative conventional value):

[0091] Thermal conductivity k_ref=0.095W / (m·K);

[0092] Bulk density = 700 kg / m³ 3 →mass / m 2 =35.0kg / m 2 ;

[0093] Compressive strength = 1.8 MPa;

[0094] Water absorption rate (24h) = 12.0%;

[0095] Peak temperature (day-night cycle) is used as the benchmark.

[0096] Thermal conductivity: Equipment—steady-state hot plate / guarded hot plate, test size 300×300×50mm; environment fixed at 23℃; test according to the instrument manual and refer to ASTM C518; 3 pieces per group, record steady-state values ​​and take the average.

[0097] Compressive strength: Equipment—Universal testing machine (Instron or equivalent), loading rate 1mm / min, sample 50×50×50mm, take the average of 5 pieces and report the deviation.

[0098] Water absorption rate: Equipment—balance, vacuum pump, water tank; measured according to ASTM C642 procedure or immersion in water for 24 hours; weigh and calculate water absorption rate (percentage).

[0099] Phase change thermal buffer (day and night cycle): Equipment - environmental chamber (programmable temperature curve), K-type thermocouple (placed on the back of the plate at 3 points and averaged), data acquisition device (recording interval 1 min). First, a 48-hour pre-test is conducted to stabilize the cycle, and finally, 48 hours of continuous data are taken to calculate the peak temperature difference and phase delay.

[0100] Porosity / Closed Pores (Optional): Report pore size distribution and percentage of closed pores using gas displacement method or microscopic image analysis.

[0101] Sample quantity and statistics: at least 3 samples (thermal conductivity) or 5 samples (mechanical) for each test, and take the average; provide the standard deviation and confidence interval.

[0102] The test comparison data for Example 1, Example 2, and the comparative example are shown in Table 1 below:

[0103] Table 1

[0104]

[0105] As shown in the table above, the thermal conductivity is significantly reduced: the in-situ aerogel framework + aerogel microsphere combination in Examples 1 / 2 breaks the solid-to-solid thermal conductivity chain, and the closed-pore structure restricts the thermal conductivity of air, thereby reducing the thermal conductivity to 0.048 / 0.032 W / (m·K) respectively.

[0106] Lightweight: Bulk density reduced from the conventional 700 kg / m³ 3 Reduced to 420 / 380kg / m 3 (mass / m) 2 Weighing 21 kg and 19 kg respectively, this material is easy to construct and saves on structural load, which aligns with the "lightweight insulation" technical requirement in the claims.

[0107] Thermal buffering capacity: By adding 3–8 parts of phase change microcapsules (6 parts in Example 1 and 8 parts in Example 2 respectively), the peak temperature is reduced by about 2.4–3.2℃ during the day-night cycle (experimental record), which helps to smooth the indoor temperature and reduce the peak energy consumption of air conditioning.

[0108] Mechanical properties and waterproofing: The surface layer adopts a "skin-core-skin" design and is bonded with a small amount of cement and fly ash polymer system. The compressive mechanical properties meet the requirements of lightweight insulation boards (≥0.8–1.0MPa), the water absorption rate is controlled at about 8–9%, and the surface is treated with silane hydrophobicity to further reduce water absorption and weather resistance issues.

[0109] Energy saving potential quantification: Based on a simplified estimate using constant ΔT, the daily heat consumption in Examples 1 and 2 is 0.6912 / 0.4608 kWh / m², respectively. 2 • day, a reduction of approximately 0.6768 / 0.9072 kWh / m compared to the conventional sample. 2 •day (approximately 49% / 66% respectively), demonstrating significant energy-saving potential in large-scale building applications.

[0110] As can be seen from the above, this invention, while ensuring excellent thermal insulation performance, balances mechanical properties and durability through material composition and microstructure design, thereby guaranteeing functional retention and engineering adaptability during long-term use. Interface strengthening of the nano-skeleton-cementing system: The silica nanoskeleton forms a connected or semi-connected rigid network within its pores, physically nesting and chemically bonding with the geopolymer / small amount of cement-based cementing system. Through interface modification measures such as coupling agents, the adhesion between the nano-network and the matrix is ​​enhanced, making it difficult for microcracks to initiate and effectively dispersing stress under macroscopic stress, thereby improving the material's crack resistance and compressive strength.

[0111] Closed-cell structure and hydrophobic treatment prevent water damage: The closed-cell porous structure itself reduces the connectivity of capillary water absorption channels, and the hydrophobic treatment of the surface and interface further inhibits the entry of external moisture. This combination significantly reduces the risk of degradation of the material's thermal and mechanical properties caused by water erosion, freeze-thaw cycles, and salt erosion, ensuring the maintenance of thermal resistance and strength over time.

[0112] Chemical stability of the low-carbon geopolymer / minimum cement system: The selection of a geopolymer-based cementing phase provides superior high-temperature and chemical corrosion resistance compared to traditional organic binders, while reducing the risk of long-term organic degradation. The coupling of this cementing system with the nanoframework helps maintain structural integrity and mitigate heat-related failures under high-temperature or fire-prone conditions.

[0113] Layered / skin-core structure for stress and functional distribution: By constructing a layered structure with a high-strength surface layer and an ultra-lightweight insulation core layer during molding, the load-bearing and insulation functions are physically distributed: the surface layer bears mechanical stress and surface wear / impact, while the core layer maximizes insulation performance and bears a lower mechanical load. This structural design significantly improves reliability and adaptability during engineering installation and long-term service.

[0114] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A wall insulation material, characterized in that, Including by mass percentage: Activated attapulgite clay 50-55 parts; silica sol 5-8 parts; aerogel microspheres 6-10 parts; phase change microcapsules 6-10 parts; expanded perlite or lightweight expanded aggregate 12-15 parts; activated fly ash or highly active slag 12-15 parts; silicate cement 6-10 parts; polypropylene chopped short fibers 0.4-0.8 parts; silane coupling agent 0.5-0.8 parts; closed-cell nucleating agent / template 0.6-1 parts; multifunctional water-reducing agent 0.3-0.5 parts; The activating liquid and water are used for activation and shaping, wherein the activating liquid and activated attapulgite are mixed in a solid:liquid ratio of 1:0.18–0.

22.

2. The wall insulation material according to claim 1, characterized in that, The phase change microcapsules are paraffin or fatty acid-based phase change cores, polymers, or silica shells, with a particle size of 10–50 μm.

3. A method for preparing a wall insulation material according to any one of claims 1-2, characterized in that, Includes the following steps: S1. Dry and finely crush the original attapulgite clay to remove free water and refine the particle size to obtain dry fine powder; S2. The dried fine powder is washed with deionized water and then dried and calcined to remove soluble impurities and expand the pore structure, thereby obtaining activated attapulgite powder. S3. The activated attapulgite powder is mixed with silica sol and then subjected to ultrasonication, high shear dispersion and low temperature gelation to form a nano-SiO2 framework in situ in the pores of the attapulgite and seal the pores to obtain nano-silica framework-attapulgite composite powder. S4. The nano-silica framework-attapulgite composite powder is dry-mixed and homogenized with aerogel microspheres, expanded perlite, phase change microcapsules, fiber, silane coupling agent and closed-cell nucleating agent according to the formula to obtain homogeneous heat buffer composite dry powder. S5. Mix the homogeneous thermal buffer composite dry powder with the activating liquid and adjust the rheology to obtain a castable slurry, thus obtaining a castable composite slurry. S6. The castable composite slurry is poured into a mold and then cured, maintained, and surface-functionalized to form a closed-cell structure through chemical foaming or template method, resulting in a finished board.

4. The method for preparing a wall insulation material according to claim 3, characterized in that, The silica sol was prepared by alcohol-water-acid catalytic hydrolysis of TEOS, with a molar ratio of TEOS:EtOH:H2O of 1:4:4 and an acid catalytic amount of 0.001–0.01 mol.

5. The method for preparing a wall insulation material according to claim 3, characterized in that, In step S2, the calcination temperature is 350–450℃, and the holding time is 1.5–3h; in step S3, the low-temperature gelation drying temperature is <90℃.

6. The method for preparing a wall insulation material according to claim 3, characterized in that, The activating solution mentioned in step S5 is a mixture of NaOH solution and water glass in the required ratio, with the solid-liquid ratio controlled at 1:0.18–0.22, and the slump of the slurry adjusted to 50–80 mm.

7. The method for preparing a wall insulation material according to claim 3, characterized in that, In step S6, when chemical foaming is used, the foaming agent is hydrogen peroxide or other controllable oxidizing foaming agent, and the amount used is 0.3–1.0 wt% of the total amount of homogeneous heat buffer composite dry powder; or when template method is used, the template is combustible or soluble microspheres with a template particle size of 0.1–2 mm.

8. The method for preparing a wall insulation material according to claim 3, characterized in that, The finished board material obtained has one or more of the following properties: bulk density ≤ 500 kg / m³ 3 ; Thermal conductivity 0.025–0.06 W / (m·K); water absorption ≤15%; compressive strength ≥0.5 MPa.

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