Inorganic microcrystal plastic insulation board and preparation method thereof

Abstract

The invention discloses an inorganic microcrystal plastic insulation board and a preparation method thereof. Comprising an aggregate system, a gelling material system and polyvinyl alcohol (PVA) short fibers, and the gelling material system comprises a gelling base material and process water; the ratio of the aggregate system to the gelling base material is (1-1.1 m): 100Kg, and the mass ratio of the process water to the gelling base material is (60-70): 100; the polyvinyl alcohol (PVA) short fibers account for 0.5%-2.0% of the total mass of the cementing material system; the inorganic microcrystal plastic insulation board and the preparation method have the advantages of high strength, low heat conductivity coefficient, light weight and low water absorption.

Description

An inorganic microcrystalline plastic insulation board and its preparation method Technical Field

[0001] This invention relates to an inorganic microcrystalline plastic insulation board and its preparation method. Background Technology

[0002] Building insulation materials are core materials for achieving building energy conservation and reducing energy consumption. Their performance directly affects the building's thermal insulation effect and structural safety. Currently, inorganic insulation boards on the market are mainly made of cement and fly ash as cementitious base materials, combined with lightweight aggregates such as vitrified microspheres and expanded graphite. Although they have advantages such as fire resistance and environmental protection, there are still many technical bottlenecks. Existing inorganic insulation boards generally face the industry problem of "difficulty in balancing lightweight and high strength": in order to pursue low density, the amount of lightweight aggregate is usually increased, but this leads to excessively high internal porosity, weak interfacial bonding, and a significant decrease in compressive and flexural strength, making them prone to cracking and falling off. On the other hand, if the amount of cementitious material is increased to enhance strength, it will lead to an increase in the density of the insulation board, an increase in thermal conductivity, and a loss of thermal insulation advantages. Meanwhile, traditional insulation boards have limited functionality, providing only basic thermal insulation without the ability to regulate temperature through phase change. This makes them ill-suited to cope with indoor temperature fluctuations caused by diurnal temperature variations. Furthermore, some products suffer from high water absorption and insufficient durability, impacting long-term performance. In addition, the cementitious systems of existing insulation boards often use conventional fine powders, resulting in insufficient hydration and low aggregate coverage, leading to segregation and bleeding, further exacerbating performance shortcomings. While some technologies attempt to introduce phase change materials or fiber reinforcements, issues such as poor compatibility of phase change materials, uneven fiber dispersion, and unreasonable aggregate gradation prevent the synergistic effect of components from being achieved, making it difficult to fundamentally improve the overall performance of insulation boards. Therefore, developing a "structure-function integrated" inorganic insulation board that combines low thermal conductivity, lightweight, high strength, low water absorption, and phase change temperature regulation has become an urgent need in the field of building insulation materials. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an inorganic microcrystalline plastic insulation board with high strength, low thermal conductivity, light weight and low water absorption.

[0004] To solve the above problems, the present invention adopts the following technical solution: An inorganic microcrystalline plastic insulation board includes an aggregate system, a cementitious material system, and polyvinyl alcohol (PVA) short fibers. The cementitious material system includes a cementitious substrate and process water. The ratio of the aggregate system to the cementitious substrate is 1~1.1 m³: 100 kg, and the mass ratio of the process water to the cementitious substrate is 60~70: 100. The polyvinyl alcohol (PVA) short fibers account for 0.5%~2.0% of the total mass of the cementitious material system. The aggregate system is composed of the following components by loose volume ratio: hollow microspheres (fine aggregate): phase change vitrified microspheres (medium-fine aggregate): phase change wood ash (medium-fine aggregate): expanded graphite particles (coarse aggregate) = 1:1:1:7. The cementitious substrate is composed of the following components by mass percentage: cement 50-70%, fly ash 20-40%, silica fume 7-9%, and redispersible latex powder 1-3%.

[0005] Furthermore, the hollow microspheres are hollow glass microspheres with a particle size of 60-80 μm, a compressive strength of 3.3-3.5 MPa, and a density of 200-300 kg / m³; the phase change vitrified microspheres have a bulk density of 110-130 kg / m³, a cylindrical compressive strength of 100-130 kPa, and are treated with composite paraffin phase change and encapsulated with acrylic emulsion. The composite paraffin has a melting point of 22-33℃, a latent heat of phase change of 120-150 J / g, and a water absorption rate of ≤2%; the phase change plant ash has a bulk density of 180-300 kg / m³, and is treated with composite paraffin phase change and encapsulated with acrylic emulsion. The composite paraffin has a melting point of 22-33℃, a latent heat of phase change of 100-130 J / g, and a water absorption rate of ≤2%; the expanded graphite particles have a particle size range of 1-3 mm and a density of 7-10 kg / m³; and the cement is ordinary Portland cement 4.25. The fly ash is of grade I (loss on ignition ≤5%, ensuring pozzolanic activity), the silica fume has a silica content ≥90% and a particle size of 0.1μm, and the redispersible latex powder is vinyl acetate / ethylene copolymer powder (minimum film-forming temperature ≤5℃, bonding strength ≥0.8MPa); the process water is tap water conforming to the "Standard for Water Used in Concrete" GB / T 14684-2022, with a water temperature of 15-25℃ and a pH value of 6.5-8.5. Its dosage needs to be adjusted to control the thixotropic index of the cementitious material system (cementing substrate + process water) to 3~3.5. The thixotropic index is the ratio (η1 / η2) of the viscosity η1 at 6 rpm and the viscosity η2 at 60 rpm of the rotational viscometer #4 rotor.

[0006] Furthermore, the phase change treatment process of the phase change vitrified microspheres includes: feeding dried (moisture content ≤1%) vitrified microspheres into a phase change treatment chamber, and spraying molten composite paraffin wax (paraffin temperature maintained at 40-50℃) through a nozzle, with the amount of composite paraffin wax being 30-40% of the mass of the vitrified microspheres; then transferring to a vacuum chamber and treating under a vacuum of -0.08~-0.09MPa for 30-45 minutes to allow the composite paraffin wax to be fully adsorbed into the internal pores of the vitrified microspheres; after obtaining the semi-finished product, sending it to a packaging chamber, and spraying acrylic emulsion (solid content 30-40%, pure acrylic emulsion type, such as BA-100) through multiple nozzles, with the amount of emulsion being 5-8% of the mass of the vitrified microspheres, while simultaneously stirring in a spiral motion at 150-200 rpm to ensure that the acrylic emulsion uniformly coats the surface of the vitrified microspheres; finally, sending it to a finished product chamber and drying it at 50-60℃ for 2-3 minutes. Within hours, phase change vitrified microspheres with a water absorption rate of ≤2% were obtained.

[0007] Furthermore, the phase change treatment process of the aforementioned phase change plant ash includes: drying the plant ash at 105℃ for 2 hours, passing it through a 100-mesh sieve, and then sending it into a phase change treatment chamber. Molten composite paraffin wax (temperature 40-50℃) is sprayed into the chamber, with the amount of composite paraffin wax being 25-35% of the plant ash mass. The plant ash is then transferred to a vacuum chamber and treated at -0.08~-0.09MPa for 40-50 minutes. After adsorption, the plant ash is sent to a sealing chamber, where acrylic emulsion (solid content 30-40%, pure acrylic emulsion type, such as BA-100) is sprayed into the chamber, with the amount of emulsion being 6-9% of the plant ash mass. The mixture is then spirally stirred and coated at 150-200 rpm. Finally, the plant ash is dried at 50-60℃ for 3-4 hours to obtain a phase change plant ash with a water absorption rate ≤2%.

[0008] Furthermore, the polyvinyl alcohol (PVA) short fibers are PVA fibers with a length of 3mm to 12mm.

[0009] Another technical problem to be solved by the present invention is to provide a method for preparing an inorganic microcrystalline plastic insulation board.

[0010] To solve the above problems, the present invention adopts the following technical solution, including the following steps: 1) Pretreatment of cementitious substrate: Cement, fly ash, silica fume, and redispersible latex powder are mixed according to the mass percentage. The mixing order is as follows: first, stir the cement and fly ash for 2-3 minutes, then add the silica fume and redispersible latex powder and continue stirring for 3-5 minutes; then put it into an ultrafine ball mill, using ceramic balls as the grinding medium (ball-to-material ratio 5:1), dry grind for 2-3 hours to a fineness of 2000 mesh, and transfer it to a dry storage silo with a temperature of 20-25℃ and a humidity of ≤40% for later use; 2) Preparation of cementitious material system (material A): According to the mass ratio of cementitious substrate: water = 100:60-70, process water is added to the pretreated cementitious substrate, and sheared and stirred at a speed of 2000-2500 rpm. The thixotropic index is monitored every 2 minutes using a rotational viscometer (model NDJ-8S); if the thixotropic index <3, add 1-2 kg. Process water; if the thixotropic index is >3.5, add 0.5-1Kg of cementitious substrate, with fine adjustments not exceeding ±2%, until the thixotropic index reaches 3~3.5, to obtain the cementitious material system (material A); 3) Preparation of material B: pre-stir the cementitious material system (material A) at 300-400 rpm for 1-2 minutes, then slowly add polyvinyl alcohol (PVA) short fibers at 0.5%~2.0% of the total mass of the cementitious material system, adjust the stirring speed to 200-300 rpm, and stir for 4-6 minutes to obtain material B; 4) Preparation of aggregate system (material C): mix hollow microspheres, phase change vitrified microspheres, phase change plant ash, and expanded graphite particles according to the loose volume ratio, put them into a twin-shaft mixer and stir at 100-150 rpm for 5-8 minutes until uniformly mixed to obtain the aggregate system; 5) Finished product preparation: put B Material C and material C are added to a mixer at a ratio of 100 kg (based on the mass of the cementitious substrate): 1~1.1 m³. The mixture is stirred for 5-8 minutes until the material is homogeneous. The mixture is then poured into a steel mold coated with an organosilicon release agent (model WD-40) on the inner wall. The mold is then pressed for 12 hours at a pressure of 0.5-1.0 MPa and a compression ratio of 50~65% using a hydraulic press. After demolding, the mold is cured for 14 days at 20~27℃ and 50~60% humidity, with the first 7 days being sealed curing and the last 7 days being ventilated curing. After curing, the mold is cut to the specified size using a diamond saw blade cutter (model J3G-400), and the edges are ground to remove burrs to obtain the finished product.

[0011] The beneficial effects of the inorganic microcrystalline plastic insulation board and its preparation method of this invention are as follows: Through the innovation of the above materials and processes, the final product achieves high strength, low thermal conductivity, light weight, and low water absorption. It is a typical "structure-function integrated" building material that surpasses the limitations of the single performance of traditional insulation materials. It effectively solves the industry problem of the difficulty in synergistically achieving lightweight and high strength, and achieves the simultaneous improvement of fatigue resistance. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 is a microscopic diagram of the aggregate gradation system of the present invention. Detailed Implementation

[0013] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention. Embodiments

[0014] An inorganic microcrystalline plastic insulation board includes an aggregate system, a cementitious material system, and polyvinyl alcohol (PVA) short fibers. The cementitious material system comprises a cementitious substrate and process water. The ratio of the aggregate system to the cementitious substrate is 1-1.1 m³: 100 kg, and the mass ratio of the process water to the cementitious substrate is 60-70: 100. The polyvinyl alcohol (PVA) short fibers account for 0.5%-2.0% of the total mass of the cementitious material. The aggregate system, by loose volume ratio, consists of the following components: hollow microspheres (fine aggregate): phase change vitrified microspheres (medium-fine aggregate): phase change wood ash (medium-fine aggregate): Expanded graphite particles (coarse aggregate) = 1:1:1:7; the hollow microspheres are hollow glass microspheres with a particle size of 60-80μm, compressive strength of 3.3-3.5MPa, density of 200-300Kg / m³, and water absorption ≤0.5%; the phase change vitrified microspheres have a bulk density of 110-130Kg / m³, a cylinder compressive strength of 100-130kPa, and are treated with composite paraffin phase change and encapsulated with acrylic emulsion. The composite paraffin has a melting point of 22-33℃, a latent heat of phase change of 120-150J / g, and a water absorption ≤2%; the phase change treatment process of the phase change vitrified microspheres includes: sending dry (moisture content ≤1%) vitrified microspheres into a phase change treatment chamber, spraying molten composite paraffin through a nozzle (paraffin temperature maintained at 40-50℃), the amount of composite paraffin being 30-40% of the mass of the vitrified microspheres; then transferring them to a vacuum chamber, under vacuum conditions... Treat the microspheres at 0.08~-0.09 MPa for 30-45 minutes to allow the composite paraffin to be fully adsorbed into the pores inside the vitrified microspheres. After obtaining the semi-finished product, transfer it to a packaging chamber and spray acrylic emulsion (30-40% solids content, pure acrylic emulsion type, such as BA-100) using multiple nozzles. The emulsion volume is 5-8% of the mass of the vitrified microspheres. Simultaneously, stir the mixture in a spiral motion at 150-200 rpm to ensure the acrylic emulsion evenly coats the surface of the vitrified microspheres. Finally, transfer the product to a finished product chamber and dry it at 50-60℃ for 2-3 minutes. Within hours, phase change vitrified microspheres with a water absorption rate ≤2% are obtained. The bulk density of the phase change plant ash is 180-300 kg / m³. After phase change treatment with composite paraffin and encapsulation with acrylic emulsion, the composite paraffin has a melting point of 22-33℃, a latent heat of phase change of 100-130 J / g, and a water absorption rate ≤2%. The phase change treatment process of the plant ash includes: drying the plant ash at 105℃ for 2 hours, passing it through a 100-mesh sieve, sending it into a phase change treatment chamber, spraying in molten composite paraffin (temperature 40-50℃), the amount of composite paraffin being 25-35% of the mass of the plant ash; transferring it into a vacuum chamber at -0.08~-0.The material is treated at 0.9 MPa for 40-50 minutes. After adsorption, it is transferred to a packaging chamber and sprayed with acrylic emulsion (solid content 30-40%, pure acrylic emulsion type, such as BA-100). The emulsion dosage is 6-9% of the mass of the wood ash. The mixture is then spirally stirred at 150-200 rpm to coat the material. Finally, it is dried at 50-60℃ for 3-4 hours to obtain phase change wood ash with a water absorption rate ≤2%. The expanded graphite particles have a particle size range of 1-3 mm and a density of 7-10 kg / m³.

[0015] The aggregate system adopts a scientific gradation of "hollow microspheres (fine aggregate), phase change vitrified microspheres (medium and fine aggregate), phase change wood ash (medium and fine aggregate), and graphite particles (coarse aggregate)" in terms of particle size and function. Through the close packing of coarse and fine aggregates, the amount of cementitious material and porosity are greatly reduced, while giving the board "multiple functions such as high strength, heat insulation, lightweight, and phase change temperature regulation". In addition, the amorphous SiO2 and K2O components in the wood ash, in addition to playing the micro-aggregate filling effect, also react with the cementitious material to give it strength in the later stage.

[0016] The cementitious substrate is composed of the following components by mass percentage: 50-70% cement, 20-40% fly ash, 7-9% silica fume, and 1-3% redispersible latex powder.

[0017] The cement is ordinary Portland cement grade 4.25, the fly ash is grade I (loss on ignition ≤5%, ensuring pozzolanic activity), the silica content of the silica fume is ≥90% and the particle size is 0.1μm, the redispersible latex powder is vinyl acetate / ethylene copolymer powder (minimum film-forming temperature ≤5℃, bond strength ≥0.8MPa); the process water is tap water that meets the "Standard for Water Used in Concrete" GB / T 14684-2022, with a water temperature of 15-25℃ and a pH value of 6.5-8.5. Its dosage needs to be adjusted to control the thixotropic index of the cementitious material system (cementing substrate + process water) to 3~3.5. The thixotropic index is the ratio (η1 / η2) of the viscosity η1 at 6 rpm and the viscosity η2 at 60 rpm of the rotational viscometer #4 rotor.

[0018] The silica fume has an average particle size on the order of 0.1µm, which can perfectly fill the gaps between cement and fly ash, producing a strong "micro-aggregate effect" and significantly improving the density of the paste. At the same time, its high pozzolanic activity can react with the cement hydration product Ca(OH)2 to generate more high-strength CSH gel. This can significantly improve compressive / flexural strength and reduce permeability. The polyvinyl alcohol (PVA) short fibers are PVA fibers with a length of 3mm to 12mm.

[0019] The preparation method of the inorganic microcrystalline plastic insulation board includes the following steps: 1) Pretreatment of the cementitious substrate: Cement, fly ash, silica fume, and redispersible latex powder are mixed according to the mass percentage. The mixing order is as follows: first, stir the cement and fly ash for 2-3 minutes, then add the silica fume and redispersible latex powder and continue stirring for 3-5 minutes; then put it into an ultrafine ball mill, using ceramic balls as the grinding medium (ball-to-material ratio 5:1), dry grind for 2-3 hours to a fineness of 2000 mesh, and transfer it to a dry storage bin with a temperature of 20-25℃ and a humidity of ≤40% for later use; 2) Preparation of the cementitious material system (material A): Add process water to the pretreated cementitious substrate at a mass ratio of 100:60-70, and shear and stir at a speed of 2000-2500 rpm. Monitor the thixotropic index every 2 minutes using a rotational viscometer (model NDJ-8S); if the thixotropic index is <3, add 1-2 kg. Process water; if the thixotropic index is >3.5, add 0.5-1 kg of cementitious substrate, with fine adjustments not exceeding ±2%, until the thixotropic index reaches 3~3.5, to obtain the cementitious material system (material A); 3) Preparation of material B: First, pre-stir the cementitious material system (material A) at a speed of 300-400 rpm for 1-2 minutes, then slowly add polyvinyl alcohol (PVA) short fibers at 0.1%~0.5% of the total mass of the cementitious substrate, adjust the stirring speed to 200-300 rpm, stir for 4-6 minutes, and observe the fiber aggregate size under a SEM microscope to be ≤50μm, to obtain material B. Specifically, the 2000-mesh ultrafine powder, with its enormous specific surface area and surface effect, forms a thicker and more stable hydration film when mixed with water. This significantly improves the cohesiveness and water retention of the cementitious slurry, achieving a near 100% encapsulation rate. This avoids direct and fragile point contact between lightweight aggregates. Furthermore, this slurry is not prone to segregation or bleeding, exhibiting excellent stability. Due to the greatly improved encapsulation rate and enhanced interfacial adhesion, only a smaller amount of cementitious slurry is needed per unit volume of insulation board to achieve complete and effective treatment of the lightweight aggregates. The lightweight aggregate is fully encapsulated and achieves sufficient structural strength. Therefore, while ensuring strength, the proportion of lightweight aggregate can be appropriately increased, or lightweight aggregate with lower density can be used, thereby directly reducing the overall density of the insulation board and achieving "lightweight". The complete encapsulation makes the lightweight aggregate no longer a defect in the structure, but a "reinforcing unit" tightly surrounded by a high-strength slurry matrix. When subjected to pressure, the stress can be evenly dispersed through the solid slurry matrix and reinforced interface, avoiding stress concentration, thereby significantly improving the overall compressive strength, flexural strength and toughness.

[0020] 4) Preparation of aggregate system (C material): Hollow microspheres, phase change vitrified microspheres, phase change plant ash, and expanded graphite particles are mixed according to their loose volume ratio. The mixture is then added to a twin-shaft mixer and stirred at 100-150 rpm for 5-8 minutes until homogeneous, obtaining the aggregate system. 5) Finished product preparation: Materials B and C are added to a mixer at a ratio of 100 kg (based on the mass of the cementitious substrate): 1-1.1 m³. The mixture is stirred for 5-8 minutes until homogeneous. The mixture is then poured into a steel mold coated with an organosilicon release agent (model WD-40) and pressed using a hydraulic press at a pressure of 0.5-1.0 MPa and a compression ratio of 50-65% for 12 hours. After demolding, the mixture is cured for 14 days at 20-27℃ and 50-60% humidity, with the first 7 days in a sealed environment and the following 7 days in a closed environment. After ventilation and curing, use a diamond saw blade cutter (model J3G-400) to cut to the specified size, grind the edges to remove burrs, and obtain the finished product.

[0021] Furthermore, this invention, through the key technical means of "ultra-fine cementitious materials," directly leads to "increased specific surface area" and "enhanced hydration activity," which in turn causes "fundamental improvement in slurry encapsulation rate and interfacial adhesion," ultimately achieving the ideal microstructure of the insulation board with "dense matrix and strong interface." Macroscopically, this manifests as "obtaining compressive strength far exceeding that of traditionally formulated insulation boards at lower density." This invention successfully breaks through the technical bottleneck of "lightweight materials are not strong enough, and strong materials are not lightweight enough," providing a new solution for the development of high-performance insulation materials.

[0022] The measurement standard for the aforementioned "loose bulk volume ratio" is GB / T 14853.1-2010 "Test Method for Bulk Density of Loose Materials"; the detection procedure for the "thixotropic index" is based on the specific operating parameters of the NDJ-8S viscometer. Example

[0023] The difference from Example 1 is that it includes an aggregate system, a cementitious material system, and polyvinyl alcohol (PVA) short fibers. The cementitious material system comprises a cementitious matrix and process water; the mass ratio of process water to the cementitious matrix is ​​60-70:100; the cementitious matrix composition is: 50% cement, 40% fly ash, 7% silica fume, and 3% redispersible latex powder. Example

[0024] The difference from Example 1 is that it includes an aggregate system, a cementitious material system, and polyvinyl alcohol (PVA) short fibers. The cementitious material system comprises a cementitious matrix and process water; the mass ratio of process water to the cementitious matrix is ​​60-70:100; the cementitious matrix composition is: 60% cement, 30% fly ash, 8% silica fume, and 2% redispersible latex powder. Example

[0025] The difference from Example 1 is that it includes an aggregate system, a cementitious material system, and polyvinyl alcohol (PVA) short fibers. The cementitious material system includes a cementitious substrate and process water. The mass ratio of the process water to the cementitious substrate is 60~70:100. The cementitious substrate consists of the following components: 70% cement, 20% fly ash, 9% silica fume, and 1% redispersible latex powder.

[0026] The following are experimental examples conducted by the applicant under several different circumstances. In the experimental examples below, the proportions of the cementitious substrate are 60% cement, 30% fly ash, 8% silica fume, and 2% redispersible latex powder. (The following data are the average values ​​of 3 parallel experiments) Experimental Example 1: Comparison Data of Ultrafine Grinding of Cementitious Materials (Note: Hollow microspheres (fine aggregate), vitrified microspheres (medium-fine aggregate), wood ash (medium-fine aggregate), graphite particles (coarse aggregate) = 1:1:1:7 mixture) 2000 mesh 1500 mesh 1000 mesh 500 mesh 300 mesh Thermal conductivity of insulation board W / m.k 0.045 0.048 0.048 0.050 0.050 Compressive strength of insulation board MPa 0.35 0.30 0.25 0.19 0.18 Flexural strength of insulation board MPa 0.45 0.4 0.35 0.25 0.2 Tensile strength kPa 160 140 130 120 100 Density kg / m³ 3 120125130140150 Table 2: Comparison Data of Aggregate Matching in Experiment Example 2 (Changes in Wood Ash) Volume Ratio 1: Hollow Microspheres (Fine Aggregate), Vitrified Microspheres (Medium-Fine Aggregate), Graphite Particles (Coarse Aggregate) = 1:2:7 Volume Ratio 2: Hollow Microspheres (Fine Aggregate), Vitrified Microspheres (Medium-Fine Aggregate), Wood Ash (Medium-Fine Aggregate), Graphite Particles (Coarse Aggregate) = 1:1:1:7 Volume Ratio 3: Hollow Microspheres (Fine Aggregate), Phase Change Vitrified Microspheres (Medium-Fine Aggregate) The mixture ratio of phase change plant ash (medium and fine aggregate) to graphite particles (coarse aggregate) is 1:1:1:7. Volumetric ratio 1. Volumetric ratio 2. Volumetric ratio 3. Thermal conductivity of insulation board (W / m.K): 0.053, 0.045, 0.048. Compressive strength of insulation board (MPa): 0.28, 0.35, 0.38. Tensile strength (kPa): 110, 160, 150. Heat storage coefficient (W / (m².K): 1.2, 1.3, 2.5. Volumetric water absorption rate: 5.6, 6.1, 4.3. Table 3 shows the aggregate gradation ratio data for Experiment Example 3. Volumetric ratio 1: Hollow microspheres (fine aggregate), phase change vitrified microspheres (medium-fine aggregate), phase change wood ash (medium-fine aggregate), graphite particles (coarse aggregate) = 1:1:1:7. Volumetric ratio 2: Hollow microspheres (fine aggregate), phase change vitrified microspheres (medium-fine aggregate), phase change wood ash (medium-fine aggregate), graphite particles (coarse aggregate) = 0.5:1.5:1:7. Volumetric ratio 3: Hollow microspheres (fine aggregate), phase change vitrified microspheres (medium-fine aggregate), phase change wood ash (medium-fine aggregate), graphite particles (coarse aggregate) = 1:1.5:1.5:6. Volume ratio 4: Hollow microspheres (fine aggregate), phase change vitrified microspheres (medium-fine aggregate), phase change wood ash (medium-fine aggregate), graphite particles (coarse aggregate) = 1:0.5:0.5:8 Mixed volume ratio 1 Volume ratio 2 Volume ratio 3 Volume ratio 4 Thermal conductivity of insulation board W / m.k 0.048 0.045 0.051 0.046 Compressive strength of insulation board MPa 0.38 0.36 0.30 0.28 Tensile strength kPa 150 135 145 120 Heat storage coefficient W / (m².K) 2.5 2.8 2.9 1.9 Volume water absorption rate 4.3 6.5 6.7 5.2 The beneficial effects of the inorganic microcrystalline plastic insulation board and its preparation method of this invention are as follows: Through the innovation of the above materials and processes, the final product achieves high strength, low thermal conductivity, light weight, and low water absorption. It is a typical "structure-function integrated" building material that surpasses the limitations of the single performance of traditional insulation materials. It effectively solves the industry problem of the difficulty in synergistically achieving lightweight and high strength, and achieves the simultaneous improvement of fatigue resistance.

[0027] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The above description shows and describes the basic principles, main features, and advantages of this invention. Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of this invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An inorganic microcrystalline plastic insulation board, characterized in that: The material comprises an aggregate system, a cementitious material system, and polyvinyl alcohol (PVA) short fibers. The cementitious material system includes a cementitious matrix and process water. The ratio of the aggregate system to the cementitious matrix is ​​1~1.1 m³: 100 kg, and the mass ratio of the process water to the cementitious matrix is ​​60~70:

100. The polyvinyl alcohol (PVA) short fibers account for 0.5%~2.0% of the total mass of the cementitious material system. The aggregate system is composed of the following components by loose volume ratio: hollow microspheres (fine aggregate): phase change vitrified microspheres (medium-fine aggregate): phase change wood ash (medium-fine aggregate): expanded graphite particles (coarse aggregate) = 1:1:1:

7. The cementitious matrix is ​​composed of the following components by mass percentage: cement 50-70%, fly ash 20-40%, silica fume 7-9%, and redispersible latex powder 1-3%.

2. The inorganic microcrystalline plastic insulation board according to claim 1, characterized in that: The hollow microspheres are hollow glass microspheres with a particle size of 60-80 μm, a compressive strength of 3.3-3.5 MPa, and a density of 200-300 kg / m³. The phase change vitrified microspheres have a bulk density of 110-130 kg / m³, a cylindrical compressive strength of 100-130 kPa, and are treated with composite paraffin phase change and encapsulated with acrylic emulsion. The composite paraffin has a melting point of 22-33℃, a latent heat of phase change of 120-150 J / g, and a water absorption rate of ≤2%. The phase change plant ash has a bulk density of 180-300 kg / m³, is treated with composite paraffin phase change and encapsulated with acrylic emulsion, and has a melting point of 22-33℃, a latent heat of phase change of 100-130 J / g, and a water absorption rate of ≤2%. The expanded graphite particles have a particle size range of 1-3 mm and a density of 7-10 kg / m³. The cement is ordinary Portland cement grade 4.25, and the fly ash is grade I. Grade (loss on ignition ≤5%, ensuring pozzolanic activity), the silica fume has a silica content ≥90% and a particle size of 0.1μm, the redispersible latex powder is vinyl acetate / ethylene copolymer powder (minimum film-forming temperature ≤5℃, bonding strength ≥0.8MPa); the process water is tap water conforming to the "Standard for Water Used in Concrete" GB / T 14684-2022, with a water temperature of 15-25℃ and a pH value of 6.5-8.

5. Its dosage needs to be adjusted to control the thixotropic index of the cementitious material system (cementing substrate + process water) to 3~3.

5. The thixotropic index is the ratio (η1 / η2) of the viscosity η1 at 6 rpm and the viscosity η2 at 60 rpm of the rotational viscometer #4 rotor.

3. The inorganic microcrystalline plastic insulation board according to claim 2, characterized in that: The phase change treatment process of the phase change vitrified microspheres includes: feeding dried (moisture content ≤1%) vitrified microspheres into a phase change treatment chamber, spraying molten composite paraffin wax (paraffin temperature maintained at 40-50℃) through a nozzle, the amount of composite paraffin wax being 30-40% of the mass of the vitrified microspheres; then transferring to a vacuum chamber, treating for 30-45 minutes under a vacuum of -0.08~-0.09MPa, allowing the composite paraffin wax to be fully adsorbed into the internal pores of the vitrified microspheres; after obtaining a semi-finished product, sending it to a packaging chamber, spraying acrylic emulsion (solid content 30-40%, pure acrylic emulsion type, such as BA-100) through multiple nozzles, the amount of emulsion being 5-8% of the mass of the vitrified microspheres, while simultaneously stirring in a spiral motion at 150-200 rpm, so that the acrylic emulsion uniformly coats the surface of the vitrified microspheres; finally sending it to a finished product chamber, drying at 50-60℃ for 2-3 hours, obtaining phase change vitrified microspheres with a water absorption rate ≤2%.

4. The inorganic microcrystalline plastic insulation board according to claim 2, characterized in that: The phase change treatment process of the aforementioned wood ash includes: drying the wood ash at 105℃ for 2 hours, passing it through a 100-mesh sieve, and then sending it into a phase change treatment chamber. Molten composite paraffin wax (temperature 40-50℃) is sprayed into the ash, with the amount of composite paraffin wax being 25-35% of the wood ash mass. The ash is then transferred to a vacuum chamber and treated at -0.08~-0.09MPa for 40-50 minutes. After adsorption, the ash is sent to a sealing chamber, where acrylic emulsion (solid content 30-40%, pure acrylic emulsion type, such as BA-100) is sprayed into the ash, with the amount of emulsion being 6-9% of the wood ash mass. The mixture is then spirally stirred and coated at 150-200 rpm. Finally, the ash is dried at 50-60℃ for 3-4 hours to obtain a phase change wood ash with a water absorption rate ≤2%.

5. The inorganic microcrystalline plastic insulation board according to claim 1, characterized in that: The polyvinyl alcohol (PVA) short fibers are PVA fibers with a length of 3mm to 12mm.

6. A method for preparing an inorganic microcrystalline plastic insulation board as described in any one of claims 1-5, characterized in that, Includes the following steps: 1) Pretreatment of cementitious substrate: Mix cement, fly ash, silica fume, and redispersible latex powder according to the following mass percentages: First, stir the cement and fly ash for 2-3 minutes, then add the silica fume and redispersible latex powder and continue stirring for 3-5 minutes; then put it into an ultrafine ball mill, using ceramic balls as the grinding medium (ball-to-material ratio 5:1), and dry grind for 2-3 hours to a fineness of 2000 mesh. Transfer it to a dry storage silo at a temperature of 20-25℃ and a humidity of ≤40% for later use. 2) Preparation of cementitious material system (A material): Add process water to the pretreated cementitious substrate according to the mass ratio of cementitious substrate:water = 100:60-70. Shear and stir at a speed of 2000-2500 rpm, and monitor the thixotropic index every 2 minutes using a rotational viscometer (model NDJ-8S); if the thixotropic index <3, add 1-2 kg of process water; if the thixotropic index >3.5, add 0.5-1 kg of process water. 1) Prepare the cementitious substrate, with fine-tuning range not exceeding ±2%, until the thixotropic index reaches 3~3.5 to obtain the cementitious material system (material A); 2) Prepare material B: Pre-stir the cementitious material system (material A) at a speed of 300-400 rpm for 1-2 minutes, then slowly add polyvinyl alcohol (PVA) short fibers at 0.5%~2.0% of the total mass of the cementitious material system, adjust the stirring speed to 200-300 rpm, and stir for 4-6 minutes to obtain material B; 3) Prepare the aggregate system (material C): Mix hollow microspheres, phase change vitrified microspheres, phase change wood ash, and expanded graphite particles according to the loose volume ratio, put them into a twin-shaft mixer and stir at 100-150 rpm for 5-8 minutes until uniformly mixed to obtain the aggregate system; 4) Prepare the finished product: Put material B and material C into the mixer at a ratio of 1~1.1 m³ per 100 kg (based on the mass of the cementitious substrate), and stir for 5-8 minutes. After the material is homogenized, it is poured into a steel mold coated with silicone release agent (model WD-40) on the inner wall. It is then pressed for 12 hours using a hydraulic press at a pressure of 0.5-1.0MPa and a compression ratio of 50-65%. After demolding, it is cured for 14 days at 20-27℃ and 50-60% humidity, with the first 7 days being sealed curing and the last 7 days being ventilated curing. After curing, it is cut to the specified size using a diamond saw blade cutter (model J3G-400), and the edges are ground to remove burrs to obtain the finished product.

Images