Inorganic resin fireproof thermal insulation material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of fireproof thermal insulation materials, and particularly relates to an inorganic resin fireproof thermal insulation material as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) uniformly mixing inorganic resin, a calcium-based modifier and reinforced fibers, and carrying out foaming treatment in a foaming agent to prepare slurry; (2) performing freeze drying treatment on the slurry to form a porous preform; and (3) carrying out carbonization treatment on the porous preform in a CO2 atmosphere to obtain the porous carbon material. The inorganic resin fireproof thermal insulation material provided by the invention has excellent thermal insulation performance and fireproof performance, high strength and light weight, and the preparation process is low-temperature, green and low-carbon.

Description

Technical Field

[0001] This invention belongs to the technical field of fireproof and thermal insulation materials, specifically relating to an inorganic resin fireproof and thermal insulation material, its preparation method, and its application. Background Technology

[0002] Currently, building insulation materials are mainly divided into two categories: organic insulation materials and inorganic insulation materials. However, both have significant technical bottlenecks, especially in balancing fire resistance and thermal conductivity.

[0003] Organic thermal insulation materials (such as polystyrene foam EPS / XPS and polyurethane PU) dominate the market due to their lightweight (density 15~50 kg / m³) and ultra-low thermal conductivity (0.022~0.040 W / (m·K)). However, their core problems are: flammability, with combustion performance generally at B1 level or lower, rapidly melting and dripping when exposed to fire, releasing toxic gases (such as hydrogen cyanide and benzene compounds), exacerbating fire hazards; poor structural stability, prone to aging and shrinkage after long-term use, leading to hollowing and detachment of exterior walls; and low temperature resistance, with polyurethane decomposing above 150℃, failing to meet the requirements of industrial pipelines (>300℃) or high-temperature fire environments. An existing improved solution, CN112479738A, discloses a multi-level porous inorganic composite polystyrene non-combustible thermal insulation material and its preparation method, which improves the fire resistance to A2 level by incorporating inorganic gel materials (silicates) and flame retardants, but the thermal conductivity rebounds to above 0.050 W / (m·K), and the mechanical properties decrease.

[0004] Inorganic materials (such as rock wool, aerogel, and foam glass) possess Class A non-combustible properties, but they have the following shortcomings: high thermal conductivity (0.036~0.050 W / (m·K)), making it difficult to meet the requirements of ultra-low energy consumption building standards (≤0.030 W / (m·K)); weak mechanical properties, with rock wool having a compressive strength of only 0.05~0.15 MPa and aerogel being brittle (easily pulverized), unable to withstand construction loads; high-energy-consuming processes, as rock wool requires melting and centrifugation at 1400℃ to form fibers, and aerogel relies on supercritical drying, resulting in carbon emissions 3~5 times that of organic materials; and uncontrollable structure, as described in CN118993615A, traditional sintering methods cannot accurately control multi-level pores (micron-nano synergy), leading to a mismatch between thermal insulation and strength performance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an inorganic resin fireproof and heat-insulating material, its preparation method, and its application. This inorganic resin fireproof and heat-insulating material has both excellent heat insulation and fireproof properties, as well as high strength, light weight, and a low-temperature, green, and low-carbon preparation process.

[0006] Specifically, the present invention provides the following technical solutions: A method for preparing an inorganic resin fireproof and heat-insulating material includes the following steps: (1) Inorganic resin, calcium-based modifier and reinforcing fiber are mixed evenly and foamed in foaming agent to obtain slurry; (2) The slurry is freeze-dried to form a porous preform; (3) The porous preform is carbonized under a CO2 atmosphere to obtain the final product.

[0007] Preferably, the mass ratio of the inorganic resin, calcium-based modifier, reinforcing fiber, and foaming agent is 60~80:5~15:10~20:1~3.

[0008] This invention uses inorganic silicate resin as the matrix, introduces a calcium-based modifier as the carbonization reaction source, and introduces reinforcing fibers to enhance the mechanical strength and structural stability of the porous preform, inhibiting cracking and shrinkage during freeze-drying, and forming a reinforcing skeleton in the final carbonization product. A foaming agent is introduced to regulate the pore structure. By coordinating the properties of different materials and optimizing the mixing ratio, each component plays a complementary role. A multi-level pore structure of 50~300μm is constructed through directional freeze-drying, and then nano-calcium carbonate is generated in situ through low-pressure CO2 carbonization to generate a reinforcing skeleton of 1~100nm and produce micropores. Finally, a fireproof and heat-insulating material with excellent comprehensive performance is obtained.

[0009] Preferably, the inorganic resin is silica sol with a solid content of 20-40 wt%.

[0010] Preferably, the calcium-based modifier is Ca(OH)2 or CaO.

[0011] Preferably, the reinforcing fiber is hollow glass fiber or ceramic fiber, with a fiber diameter of 3~15μm and a length of 100~500μm.

[0012] Preferably, the foaming agent comprises sodium dodecyl sulfonate (SDS), polyethylene glycol (PEG-400), and silicone oil in a mass ratio of 2~5:8~15:0.5~2. The use of this composite foaming agent can synergistically regulate the surface tension and viscosity of the slurry, ensuring uniform foaming and stable bubble size, thereby precisely controlling the pore size and distribution of macropores (50-300 μm), significantly reducing material density and improving thermal insulation performance.

[0013] Preferably, in step (1), the foaming treatment specifically involves stirring at 300-700 rpm at 5-15℃ until the slurry viscosity reaches 800-1200 mPa·s. Studies have found that when the slurry viscosity is below this range, the slurry becomes too fluid, causing bubbles to quickly merge and break, resulting in a coarse and uneven pore structure, increased density, and decreased thermal insulation performance. When the slurry viscosity is above this range, uneven mixing and dispersion occur, making foaming difficult and hindering the formation of uniform bubbles within the slurry, leading to low porosity and increased material brittleness. The method for detecting the slurry viscosity is as follows: a rotational viscometer (such as the NDJ-79 type) is used at a specific rotational speed (such as 6 rpm) for testing, conforming to the relevant provisions of GB / T 2794-2013 "Determination of Viscosity of Adhesives".

[0014] Preferably, in step (2), directional freeze-drying is the key to constructing directional macropores (50-300 μm), while segmented vacuum drying can control the ice crystal sublimation rate and avoid the collapse of the preform structure, which is a necessary condition to ensure high porosity and bimodal pore structure. The freeze-drying process includes the following steps: A. Freeze-forming: First, cool to -22 to -18°C at 4~6°C / min, then cool to -42 to -38°C at 2~4°C / min, and hold for 4-6 hours; B. Vacuum drying: The vacuum degree is controlled below 10Pa (i.e., the absolute pressure is below 10Pa). First, the temperature is raised to -22~-18℃ and held for 5-8 hours. Then, the temperature is raised to -2~2℃ and held for 10-12 hours. Finally, the temperature is raised to 18~22℃ and held until the moisture content of the material is ≤0.5%.

[0015] Preferably, in step (3), the carbonization conditions are: CO2 pressure 0.1-1 MPa, temperature 40-80℃, and processing time 2-8 hours.

[0016] The present invention also provides an inorganic resin fireproof and heat-insulating material, which is prepared by the above preparation method.

[0017] Preferably, the inorganic resin fireproof and heat-insulating material has a porosity of 85-95%; Among them, macropores with a pore size in the range of 50-300μm account for 60-80% of the total volume of all pores, while micropores with a pore size in the range of 1-100nm account for 20-40% of the total volume of all pores.

[0018] The present invention also provides the application of the above-mentioned inorganic resin fireproof and thermal insulation materials in building exterior wall insulation or industrial pipeline insulation.

[0019] The beneficial effects of this invention are at least as follows: (1) The inorganic resin fireproof and heat-insulating material provided by the present invention has a thermal conductivity of 0.025-0.030W / (m·K) and a combustion performance that reaches GB8624 A1 level (non-combustible, no toxic smoke), and has both excellent heat insulation and fireproof performance. (2) The inorganic resin fireproof and heat-insulating material provided by the present invention has a compressive strength of 1.5-3.0MPa and good mechanical properties; at the same time, the density is ≤100 kg / m³ and the weight is light.

[0020] (3) The inorganic resin fireproof and heat-insulating material provided by the present invention does not require high-temperature sintering during the preparation process, and at the same time utilizes industrial CO2, and the preparation process is low-temperature, green and low-carbon. (4) The inorganic resin fireproof and heat-insulating material provided by the present invention preferably uses sodium dodecyl sulfonate (SDS), polyethylene glycol (PEG-400) and silicone oil in a mass ratio of 2~5:8~15:0.5~2 as foaming agents, which significantly reduces the material density and improves the heat insulation performance. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art, or in accordance with the product manual.

[0022] In the following examples, the inorganic resin used is silica sol with a solid content of 30 wt%; The reinforcing fibers used have a diameter of 3-15μm and a length of 100-500μm; The foaming agent used is sodium dodecyl sulfonate, polyethylene glycol and silicone oil in a mass ratio of 3:12:1.

[0023] Example 1 Example 1 provides an inorganic resin fireproof and heat-insulating material, the preparation method of which is as follows: Mixing process: Inorganic resin is added to a mixing tank, followed by calcium-based modifier Ca(OH)2 and hollow glass fiber, and then ultrasonically dispersed for 10 minutes. Foaming treatment: Add composite foaming agent, stir at 500 rpm / min at 10℃ until the volume expands 2.2 times, and control the final slurry viscosity at 1000 mPa·s; the mass ratio of the inorganic resin, calcium-based modifier, hollow glass fiber and composite foaming agent is 70:10:15:2. Frozen forming: Using a polytetrafluoroethylene mold, the mold is pre-cooled to -10℃, and frozen in stages. The first stage is 5℃ / min (0→-20℃), and the second stage is 3℃ / min (-20→-40℃). A temperature gradient of 25℃ / cm is established, and the temperature is held at -40℃ for 6 hours. Vacuum drying: The cold trap temperature is controlled at -55℃, the vacuum degree is 10Pa, and the drying is carried out in stages, with the temperature maintained at -20℃ for 5 hours, 0℃ for 10 hours, and 20℃ for 3 hours. The moisture content of the material is 0.5%. CO2 carbonization treatment: Introduce CO2 gas with a purity ≥99.5%, control the pressure at 0.5±0.05MPa, control the temperature at 40℃ for 1 hour, 60℃ for 4 hours, and 80℃ for 1 hour, and the gas flow rate is 0.8L / min; Post-processing: Allow to cool naturally to below 40℃, slowly depressurize to atmospheric pressure, dry at 60℃ for 2 hours, and control the final moisture content to be no more than 0.3%.

[0024] Example 2 Example 2 provides an inorganic resin fireproof and heat-insulating material, the preparation method of which is as follows: Mixing process: Inorganic resin is added to a stirred tank, followed by calcium-based modifier Ca(OH)2 and ceramic fiber, and then dispersed at 3000 rpm / min for 6 min. Foaming treatment: Add composite foaming agent, stir at 700 rpm / min at 5℃, and control the final slurry viscosity at 1200 mPa·s; the mass ratio of the inorganic resin, calcium-based modifier, ceramic fiber and composite foaming agent is 70:10:15:2. Frozen forming: Using a polytetrafluoroethylene mold, the mold is pre-cooled to -10℃, and frozen in stages. The first stage is 5℃ / min (0→-20℃), and the second stage is 3℃ / min (-20→-40℃). A temperature gradient of 25℃ / cm is established, and the temperature is held at -40℃ for 4 hours. Vacuum drying: The cold trap temperature is controlled at -55℃, the vacuum degree is 8Pa, and the drying is carried out in stages, with -20℃ maintained for 6 hours, 0℃ maintained for 10 hours, and 20℃ maintained for 4 hours. The moisture content of the material is 0.4%. CO2 carbonization treatment: Introduce CO2 gas with a purity ≥99.5%, control the pressure at 0.8±0.05MPa, control the temperature at 40℃ for 1 hour, 60℃ for 2 hours, and 80℃ for 2 hours, and the gas flow rate is 0.8L / min; Post-processing: Allow to cool naturally to below 40℃, slowly depressurize to atmospheric pressure, dry at 60℃ for 2 hours, and control the final moisture content to be no more than 0.3%.

[0025] Example 3 Example 3 provides an inorganic resin fireproof and heat-insulating material, the preparation method of which is as follows: Mixing process: Inorganic resin is added to a mixing tank, followed by calcium-based modifier CaO, hollow glass fiber and ceramic fiber, and ultrasonically dispersed for 12 minutes. Foaming treatment: Add composite foaming agent, stir at 700 rpm / min at 15℃ until the volume expands by 2.2 times, and control the final slurry viscosity at 800 mPa·s; the mass ratio of inorganic resin, calcium-based modifier, reinforcing fiber and composite foaming agent is 70:10:15:2, and the mass ratio of hollow glass fiber and ceramic fiber in the reinforcing fiber is 1:1; Frozen forming: Using a polytetrafluoroethylene mold, the mold is pre-cooled to -10℃, and frozen in stages. The first stage is 5℃ / min (0→-20℃), and the second stage is 3℃ / min (-20→-40℃). A temperature gradient of 25℃ / cm is established, and the temperature is held at -40℃ for 5 hours. Vacuum drying: The cold trap temperature is controlled at -55℃, the vacuum degree is 10Pa, and the drying is carried out in stages, with -20℃ maintained for 6 hours, 0℃ maintained for 10 hours, and 20℃ maintained for 4 hours. The moisture content of the material is 0.2%. CO2 carbonization treatment: Introduce CO2 gas with a purity ≥99.5%, control the pressure at 1±0.05MPa, control the temperature at 40℃ for 2 hours, 60℃ for 3 hours, and 80℃ for 3 hours, and the gas flow rate is 0.8L / min; Post-processing: Allow to cool naturally to below 40℃, slowly depressurize to atmospheric pressure, dry at 60℃ for 2 hours, and control the final moisture content to be no more than 0.3%.

[0026] Comparative Example 1 Compared with Example 1, the only difference is that no composite foaming agent was added, the "foaming treatment" step was not included, and the liquid obtained from the "mixing process" was directly frozen and molded.

[0027] Comparative Example 2 Compared with Example 1, the only difference is that CO2 carbonization and post-treatment were not performed after freeze forming and vacuum drying.

[0028] The performance test results of Examples 1-3 and Comparative Examples 1-2 are shown in Table 1.

[0029] Table 1

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an inorganic resin fireproof and heat-insulating material, characterized in that, Includes the following steps: (1) Inorganic resin, calcium-based modifier and reinforcing fiber are mixed evenly and foamed in foaming agent to obtain slurry; (2) The slurry is freeze-dried to form a porous preform; (3) The porous preform is carbonized under a CO2 atmosphere to obtain the final product.

2. The preparation method according to claim 1, characterized in that, The mass ratio of the inorganic resin, calcium-based modifier, reinforcing fiber, and foaming agent is 60~80:5~15:10~20:1~3.

3. The preparation method according to claim 1 or 2, characterized in that, The inorganic resin is silica sol with a solid content of 20-40 wt%. The calcium-based modifier is Ca(OH)2 or CaO.

4. The preparation method according to claim 1 or 2, characterized in that, The reinforcing fiber is hollow glass fiber or ceramic fiber, with a fiber diameter of 3~15μm and a length of 100~500μm.

5. The preparation method according to claim 1 or 2, characterized in that, The foaming agent consists of sodium dodecyl sulfonate, polyethylene glycol, and silicone oil in a mass ratio of 2~5: 8~15: 0.5~2.

6. The preparation method according to claim 1 or 2, characterized in that, In step (1), the foaming process specifically involves stirring at 300-700 rpm at 5-15℃ until the slurry viscosity is 800-1200 mPa·s.

7. The preparation method according to claim 1 or 2, characterized in that, In step (2), the freeze-drying process includes the following steps: A. Freeze-forming: First, cool to -22 to -18°C at 4~6°C / min, then cool to -42 to -38°C at 2~4°C / min, and hold for 4-6 hours; B. Vacuum drying: The vacuum degree is controlled below 10Pa. First, the temperature is raised to -22~-18℃ and held for 5-8 hours. Then, the temperature is raised to -2~2℃ and held for 10-12 hours. Finally, the temperature is raised to 18~22℃ and held until the moisture content of the material is ≤0.5%.

8. The preparation method according to claim 1 or 2, characterized in that, In step (3), the carbonization conditions are: CO2 pressure 0.1~1MPa, temperature 40~80℃, and processing time 2~8 hours.

9. An inorganic resin fireproof and heat-insulating material, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8; Preferably, the inorganic resin fireproof and heat-insulating material has a porosity of 85-95%; Among them, macropores with a pore size in the range of 50~300μm account for 60~80% of the total volume of all pores, and micropores with a pore size in the range of 1~100nm account for 20~40% of the total volume of all pores.

10. The application of the inorganic resin fireproof and thermal insulation material prepared by the preparation method according to any one of claims 1 to 8 or the inorganic resin fireproof and thermal insulation material according to claim 9 in building exterior wall insulation or industrial pipeline insulation.

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