Thermal and fire insulation layer and method for manufacturing a multi-layer fire jacket

Abstract

This invention belongs to the technical field of building envelope materials, and discloses a method for preparing a heat-insulating and fire-resistant layer and a multi-layer fire-resistant protective sleeve. The heat-insulating and fire-resistant layer is composed of a compound aerogel material, a modified flame-retardant synergist, a dispersant, and a magnesium oxysulfate gelling agent. The magnesium oxysulfate gelling agent serves as the matrix skeleton, providing basic structural strength and fire resistance. The compound aerogel material provides heat insulation and reduces the thermal conductivity. The modified flame-retardant synergist works synergistically to enhance and broaden the fire resistance rating. The dispersant ensures uniform mixing and a dense structure, achieving a synergistic effect of the multi-layer structure. The protective sleeve, from the inside out, includes a base layer, a transition bonding layer, a core heat-insulating and fire-resistant layer, and a surface protective layer. Each layer works synergistically through specific formulations and preparation processes to achieve excellent performance. It is suitable for high-rise buildings, data centers, and other scenarios with stringent fire and heat insulation requirements, and has both industrial production feasibility and market application value.

Description

Technical Field

[0001] This invention belongs to the technical field of building envelope materials, specifically a method for preparing a heat-insulating and fireproof layer and a multi-layer fireproof sheath. Background Technology

[0002] With the increasing demands for fire safety and energy conservation in the construction industry, building envelope panels, as a core component of the building envelope, have seen their fire resistance, thermal insulation, and long-term stability become key technical indicators. Currently, the mainstream building envelope panels on the market are mainly divided into two categories: one is a composite panel made with ordinary silicate cement as the base material, combined with insulation layers such as polystyrene foam and extruded polystyrene board. Although this type of panel has a lower cost, the fire resistance rating of polystyrene insulation materials is only Class B, making them easily combustible and releasing toxic gases such as styrene and carbon monoxide. Furthermore, the cement base material is heavy and has limited thermal insulation performance (thermal conductivity typically > 0.15 W / (m·K)). The other type is made with a single magnesium-based binder (such as magnesium oxysulfate or magnesium oxychloride) as the base material, combined with rock wool and glass wool. Fireproof boards made from this material have improved fire resistance, but they have performance defects due to the use of a single magnesium-based binder. Magnesium oxysulfate binder has good water resistance but slow early strength development (initial setting time is often <2h, and the construction window is short), while magnesium oxychloride binder has high early strength but poor water resistance (strength loss rate >10% after 24h of immersion). Furthermore, the thermal insulation performance of rock wool and glass wool (thermal conductivity ≈0.04W / (m·K)) still cannot meet the energy-saving requirements of modern buildings. At the same time, interlayer bonding often relies on a single adhesive, which can easily lead to delamination and detachment under high-temperature conditions.

[0003] Existing technologies for optimizing the function of insulation panels often focus on improving a single performance aspect, such as increasing the thickness of the insulation layer to improve thermal insulation or adding a single flame retardant to improve fire resistance. They fail to form a synergistic design encompassing the entire system of "substrate-bonding-function-protection." For example, patent CN111531675A discloses a thermal insulation straw board for exterior walls, its preparation method, and its application. However, the flame retardant used is a traditional mixture of solid and liquid flame retardants, with multiple flame retardants simply compounded. The lack of a tiered protection between gaseous and condensed phase flame retardancy limits the flame retardant efficiency. Liquid flame retardants are prone to migration and volatilization, exhibiting poor long-term stability and insufficient high-temperature resistance. Furthermore, the flame retardant system lacks a high-temperature ceramic coating layer, resulting in limited oxygen barrier capabilities and a short fire resistance time. These issues prevent its widespread use.

[0004] In summary, while thermal insulation and fireproof boards are indeed used in the field of building envelope materials, they still suffer from poor long-term stability, insufficient high-temperature resistance, and limited oxygen barrier capabilities, resulting in short fire protection time. Therefore, it is of great significance to develop a thermal insulation and fireproof layer with excellent thermal insulation and fireproof performance, good water resistance and aging resistance, and strong support, as well as multi-layer fireproof panels. Summary of the Invention

[0005] The purpose of this invention is to provide a heat-insulating and fire-resistant layer. The heat-insulating and fire-resistant layer is composed of a compound aerogel material, a modified flame-retardant synergist, a dispersant, and a magnesium oxysulfate gelling agent. The magnesium oxysulfate gelling agent serves as the matrix framework, providing basic structural strength and fire resistance. The compound aerogel material provides heat insulation and reduces the thermal conductivity. The modified flame-retardant synergist works synergistically to enhance and broaden the fire resistance rating. The dispersant ensures uniform mixing and a dense structure, achieving a multi-layered synergistic effect.

[0006] Another object of the present invention is to provide a method for preparing a multilayer fireproof sheath. The method involves sequentially coating a substrate, an intermediate bonding layer, a heat-insulating and fire-resistant layer, and a surface protective layer to form a multilayer fireproof sheath.

[0007] The objective of this invention is achieved through the following solution: A heat-insulating and fire-resistant layer, the heat-insulating and fire-resistant layer comprising the following components by mass fraction: 70%-85% compound aerogel material, 3%-5% modified flame retardant synergist, 0.5%-1.5% dispersant, and 10%-30% magnesium oxysulfate gelling agent.

[0008] Preferably, the heat-insulating and fire-resistant layer comprises the following components by mass fraction: 75%-82% compound aerogel material, 3.8%-4.2% modified flame retardant synergist, 0.8%-1.2% dispersant, and 12%-18% magnesium oxysulfate gelling agent.

[0009] The compound aerogel material is filled with a nanoporous structure, which can effectively block heat conduction and convection and significantly reduce the thermal conductivity. The modified flame retardant synergist interrupts combustion in a synergistic way through heat absorption, covering and isolation, capturing free radicals, and diluting combustible gases, thereby improving and broadening the fire resistance rating. The dispersant reduces interparticle friction, prevents agglomeration, and ensures that the components are evenly distributed in the matrix to form a homogeneous structure. The magnesium oxysulfate gelling agent hardens in air to form a high-strength matrix that is non-flammable and stable at high temperatures, providing basic structural strength and fire resistance.

[0010] Preferably, in the composite aerogel material, the mass fraction of silica aerogel is 50-65% of the heat insulation and fireproof layer, and the mass fraction of zirconia aerogel is 20-35% of the heat insulation and fireproof layer; the bulk density of the silica aerogel is 50-80 kg / m³. 3 The thermal conductivity is ≤0.018 W / (m·K); the bulk density of the zirconia aerogel is 80-120 kg / m³. 3 .

[0011] The nanoporous structure (pore size 2-50nm) of silica aerogel blocks air convection and thermal radiation, while the high-temperature resistant crystal structure (ZrO2 stable phase) of zirconia aerogel resists high-temperature sintering. After the combination, the thermal conductivity is reduced to 0.012-0.015W / (m·K), and the structure remains stable at a high temperature of 1200℃.

[0012] Preferably, the modified flame retardant synergist contains 1.5-3% by mass of nano-magnesium hydroxide, 0.6-1.5% by mass of zinc borate, and 0.3-1% by mass of melamine cyanurate; the nano-magnesium hydroxide has a particle size of 50-100 nm and a decomposition temperature ≥340℃, and the zinc borate contains ≥98% ZnB2O4.

[0013] Nano-magnesium hydroxide decomposes and releases H2O above 340℃, lowering the ambient temperature. The generated water vapor dilutes the concentration of oxygen and combustible gases. The resulting magnesium oxide is a dense refractory oxide that covers the material surface, isolating heat and oxygen. Zinc borate forms a glassy B2O3 coating at high temperatures, preventing oxygen from contacting combustibles. The hydroxyl groups and other groups in the material react to promote the formation of a stable and dense char layer. At high temperatures, it releases bound water, diluting gases and extending fire resistance time. Melamine cyanurate sublimates directly at 300-400℃, absorbing a large amount of heat and producing non-flammable gases that dilute combustible gases and oxygen. The decomposition of residues promotes charring of the matrix.

[0014] Preferably, the dispersant contains a polycarboxylate dispersant with a mass fraction of 0.3-1.05% of the heat insulation and fireproof layer, and a naphthalene sulfonate formaldehyde condensate with a mass fraction of 0.15-0.6% of the heat insulation and fireproof layer; the polycarboxylate dispersant has a solid content of ≥40%.

[0015] Polycarboxylate dispersants disperse aerogel particles uniformly through electrostatic repulsion (-COO⁻ and the positive charge on the aerogel surface). Simultaneously, their polyether side chains extend in water, forming a three-dimensional barrier to prevent particle proximity, resulting in long-lasting dispersion. This dispersion is less affected by system ion concentration, significantly reduces water surface tension, has a high water reduction rate, greatly improves slurry fluidity and castability, and provides some slump retention, preventing the slurry from thickening too quickly. Naphthalene sulfonate formaldehyde condensate molecules ionize with sulfonic acid groups to generate strong negative charges, creating strong electrostatic repulsion between particles and dispersing them. This results in a high water reduction rate, improved initial fluidity, and increased early density and strength. The synergistic effect of these two agents—naphthalene-based dispersants—leads to rapid adsorption and strong electrostatic disintegration of large aggregates, while the long chains of polycarboxylate provide more robust adsorption and encapsulation, offering lasting spatial stability. This simultaneously enhances the mechanical strength, fire resistance, heat insulation uniformity, and durability of the board.

[0016] This invention discloses a method for preparing a multi-layer fireproof sheath, comprising the following steps: S1: Dry carbon fiber, glass fiber, basalt fiber; high-speed dispersed nano-calcium carbonate, nano-magnesium hydroxide, silicon carbide micro powder; S2: Prepare the base layer, apply an over-adhesion layer to the base layer, lay a heat-insulating and fireproof layer on the over-adhesion layer, and apply a surface protective layer on the heat-insulating and fireproof layer. S3: Place the mold in a curing room at 25-35℃ and 60%-80% relative humidity for 7-10 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product.

[0017] Preferably, the specific steps of S2 are as follows: After adding water to the base layer material, it is stirred with a double-spiral mixer at 500 r / min for 15 min to obtain slurry I, poured into a mold, vibrated at 20-30 Hz and 0.5 mm amplitude for 3-5 min, and then placed in a pre-curing chamber for pre-curing; after adding water to the transition bonding layer material, it is stirred with a planetary mixer at 800 r / min for 8 min to obtain slurry II, which is then coated onto the base layer surface with a scraper at a speed of 0.5-1 m / min and allowed to stand at room temperature for 10-20 min; after adding water to the heat insulation and fireproof layer material... The mixture is stirred for 12 minutes using a plow-type mixer at 300 r / min, and then spread on the surface of the transition bonding layer. It is compacted with a roller at 0.1-0.3 MPa and 0.3-0.5 m / min and placed in a pre-curing chamber for pre-curing. The raw material for the surface protective layer is mixed with water and dispersed and stirred at 1500 r / min for 20 minutes to obtain slurry III. It is then coated with a spraying device with a diameter of 1.5-2 mm and a pressure of 0.3-0.5 MPa. After being trimmed with a scraper, it is vibrated at 15-20 Hz and an amplitude of 0.3 mm for 1-2 minutes.

[0018] The base layer, with its double-helix medium-speed mixing, ensures uniform dispersion of long fibers without excessive shearing, forming the main load-bearing layer and pre-curing to achieve initial strength. The transition bonding layer, with its planetary mixing and high-speed homogenization, ensures high uniformity of the binder. Applying this transition bonding layer seals the pores of the base layer, preventing excessive absorption of moisture from the upper layer and ensuring its hydration. The core heat-insulating and fire-resistant layer, with its plow-like mixing and low-speed agitation, prevents the crushing of lightweight aggregates and damage to the flame retardant structure. This lightweight, porous, and homogeneous layer enhances overall heat insulation and fire resistance. The surface protective layer, with its high-speed dispersion mixing, ensures full dispersion of nanofillers, forming a highly homogeneous and fine slurry. High-pressure spraying achieves a thin and dense coating, resisting environmental erosion such as moisture, ultraviolet radiation, abrasion, and chemical corrosion, providing durability and enhancing overall integrity.

[0019] Preferably, the viscosity of slurry I is 8000-10000 mPa·s, the viscosity of slurry II is 12000-15000 mPa·s, and the bulk density of the mixture is 150-200 kg / m³. 3 The viscosity of slurry III is 6000-8000 mPa·s.

[0020] Preferably, the pre-curing room conditions are a temperature of 20-25℃ and a relative humidity of 60%-70%; the base layer is pre-cured for 2-4 hours, and the heat insulation and fireproof layer is pre-cured for 3-5 hours.

[0021] Preferably, the thickness of the base layer is 8-15 mm, the thickness of the transition bonding layer is 1-3 mm, the thickness of the heat insulation and fireproof layer is 10-25 mm, and the thickness of the surface protective layer is 2-5 mm. Pre-curing of the base layer can induce structuring, and the magnesium oxysulfate gelling agent begins to hydrate and form a preliminary network skeleton, improving the supporting strength. Pre-curing of the heat insulation and fireproof layer allows the magnesium oxysulfate gelling agent to encapsulate and fix aerogel, flame retardant and other components, stabilizing the lightweight porous microstructure and strengthening the interface with the transition layer to improve the strength of the board.

[0022] The beneficial effects of this invention are as follows: (1) The compound preparation of the heat insulation and fireproof layer has extremely high fire resistance limit and high temperature structural stability, and at the same time realizes the "heat insulation" and "fireproof" performance of the board. (2) The sheathing board is multi-layered, and the steps of pre-curing the base layer, scraping, low-pressure compaction, and interlayer pre-curing ensure that the high-strength base layer resists deformation, the dense surface layer blocks water vapor erosion, and the internal functional layer can work for a long time in a dry and stable environment. The interlayer bonding strength is high, and the water resistance and anti-aging performance are excellent. It is suitable for high-rise buildings, data centers and other scenarios with strict fire protection and heat insulation requirements. It has both industrial production feasibility and market application value. Detailed Implementation

[0023] Example 1:

[0024] This embodiment provides a heat-insulating and fire-resistant layer, specifically comprising the following components by mass fraction: The compound aerogel material comprises 80%, modified flame retardant synergist 4%, dispersant 1%, and magnesium oxysulfate gelling agent 15%. The composite aerogel material comprises 58% silica aerogel and 22% zirconia aerogel. The modified flame retardant synergist comprises 2.4% nano-magnesium hydroxide, 1.2% zinc borate, and 0.4% melamine cyanurate; The dispersant contains 0.6% polycarboxylate dispersant and 0.4% naphthalene sulfonate formaldehyde condensate. The mass ratio of water to magnesium oxysulfate gelling agent is 0.5:1.

[0025] This embodiment also provides a multi-layer fireproof sheath panel, specifically including: Base layer formula: 65% magnesium oxysulfate gelling agent, 1.5% carbon fiber, 3% glass fiber, 3.5% basalt fiber, 12% ultrafine talc powder, 12% heavy calcium carbonate, 2% nano calcium carbonate, 1% citric acid; the mass ratio of water to magnesium oxysulfate gelling agent is 0.4:1. Transition bonding layer formulation: 92% magnesium oxychloride adhesive, 4% KH-550 silane coupling agent, 3% titanate coupling agent, 3% epoxy modified polyurethane, 1.5% organobentonite; the mass ratio of water to magnesium oxychloride adhesive is 0.2:1. Surface protective layer formulation: 80% magnesium oxychloride adhesive, 8% intumescent acrylic fire retardant coating, 6% phosphate ester flame retardant coating, 4% UV-P, 3% 1010, 3% silicon carbide micro powder, 11.5% UV-53; water to magnesium oxychloride adhesive mass ratio 0.3:1.

[0026] This embodiment also provides a method for preparing a multi-layer fireproof sheath, which specifically includes the following steps: S1: Place carbon fiber, glass fiber, and basalt fiber in a drying oven at 80℃ for 2 hours to remove moisture; pre-disperse nano-calcium carbonate, nano-magnesium hydroxide, and silicon carbide micro powder using a high-speed disperser at 3000r / min for 10 minutes; place magnesium oxysulfate gelling agent and magnesium oxychloride adhesive at room temperature for 24 hours to balance humidity; S2: The base layer material, after being mixed with water, is stirred for 15 minutes using a double-spiral mixer at 500 r / min to obtain slurry I with a viscosity of 9000 mPa·s. This slurry is poured into a mold and vibrated at 25 Hz with an amplitude of 0.5 mm for 5 minutes. It is then pre-cured for 3 hours in a pre-curing room at 25℃ and 65% relative humidity. The transition bonding layer material, after being mixed with water, is stirred for 8 minutes using a planetary mixer at 800 r / min to obtain slurry II with a viscosity of 13000 mPa·s. This slurry is applied to the base layer surface using a scraper at a speed of 0.8 m / min and allowed to stand at room temperature for 15 minutes. The core heat insulation and fireproof layer material, after being mixed with water, is stirred for 12 minutes using a plow-type mixer at 300 r / min to obtain a mixture with a bulk density of 180 kg / m³. 3 The material is laid on the surface of the transition bonding layer and compacted with a 0.2MPa, 0.2m / min pressure roller. It is then pre-cured in a pre-curing chamber for 4 hours. The raw material for the surface protective layer is mixed with water and dispersed and stirred at 1500r / min for 20min to obtain slurry III with a viscosity of 7000mPa·s. It is then coated with a spraying device with a diameter of 1.5mm and a pressure of 0.4MPa. After being trimmed with a scraper, it is vibrated at 20Hz and an amplitude of 0.3mm for 2min. S3: Place the mold in a curing room at 30℃ and 70% relative humidity for 8 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product. Example 2:

[0027] This embodiment provides a heat-insulating and fire-resistant layer, specifically comprising the following components by mass fraction: The compound aerogel material comprises 80%, modified flame retardant synergist 4%, dispersant 1%, and magnesium oxysulfate gelling agent 15%. The composite aerogel material comprises 55% silica aerogel and 25% zirconia aerogel. The modified flame retardant synergist comprises 1.5% nano-magnesium hydroxide, 2.1% zinc borate, and 0.4% melamine cyanurate; The dispersant comprises 0.6% polycarboxylate dispersant and 0.4% naphthalene sulfonate formaldehyde condensate; The mass ratio of water to magnesium oxysulfate gelling agent is 0.5:1.

[0028] This embodiment also provides a multi-layer fireproof sheath panel, specifically including: Base layer formula: 65% magnesium oxysulfate gelling agent, 1.5% carbon fiber, 3% glass fiber, 3.5% basalt fiber, 12% ultrafine talc powder, 12% heavy calcium carbonate, 2% nano calcium carbonate, 1% citric acid; the mass ratio of water to magnesium oxysulfate gelling agent is 0.4:1. Transition bonding layer formulation: 92% magnesium oxychloride adhesive, 4% KH-550 silane coupling agent, 3% titanate coupling agent, 3% epoxy modified polyurethane, 1.5% organobentonite; the mass ratio of water to magnesium oxychloride adhesive is 0.2:1. Surface protective layer formulation: 80% magnesium oxychloride adhesive, 8% intumescent acrylic fire retardant coating, 6% phosphate ester flame retardant coating, 4% UV-P, 3% 1010, 3% silicon carbide micro powder, 11.5% UV-53; water to magnesium oxychloride adhesive mass ratio 0.3:1.

[0029] This embodiment also provides a method for preparing a multi-layer fireproof sheath, which specifically includes the following steps: S1: Place carbon fiber, glass fiber, and basalt fiber in a drying oven at 80℃ for 2 hours to remove moisture; pre-disperse nano-calcium carbonate, nano-magnesium hydroxide, and silicon carbide micro powder using a high-speed disperser at 3000r / min for 10 minutes; place magnesium oxysulfate gelling agent and magnesium oxychloride adhesive at room temperature for 24 hours to balance humidity; S2: The base layer material, after being mixed with water, is stirred for 15 minutes using a double-spiral mixer at 500 r / min to obtain slurry I with a viscosity of 9000 mPa·s. This slurry is poured into a mold and vibrated at 25 Hz with an amplitude of 0.5 mm for 5 minutes. It is then pre-cured for 3 hours in a pre-curing room at 25℃ and 65% relative humidity. The transition bonding layer material, after being mixed with water, is stirred for 8 minutes using a planetary mixer at 800 r / min to obtain slurry II with a viscosity of 13000 mPa·s. This slurry is applied to the base layer surface using a scraper at a speed of 0.8 m / min and allowed to stand at room temperature for 15 minutes. The core heat insulation and fireproof layer material, after being mixed with water, is stirred for 12 minutes using a plow-type mixer at 300 r / min to obtain a mixture with a bulk density of 180 kg / m³. 3 The material is laid on the surface of the transition bonding layer and compacted with a 0.2MPa, 0.2m / min pressure roller. It is then pre-cured in a pre-curing chamber for 4 hours. The raw material for the surface protective layer is mixed with water and dispersed and stirred at 1500r / min for 20min to obtain slurry III with a viscosity of 7000mPa·s. It is then coated with a spraying device with a diameter of 1.5mm and a pressure of 0.4MPa. After being trimmed with a scraper, it is vibrated at 20Hz and an amplitude of 0.3mm for 2min. S3: Place the mold in a curing room at 32℃ and 65% relative humidity for 7 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product. Example 3:

[0030] This embodiment provides a heat-insulating and fire-resistant layer, specifically comprising the following components by mass fraction: The compound aerogel material comprises 70%, modified flame retardant synergist 3%, dispersant 0.5%, and magnesium oxysulfate gelling agent 10%. The composite aerogel material comprises 45% silica aerogel and 25% zirconium oxide aerogel. The modified flame retardant synergist comprises 1.8% nano-magnesium hydroxide, 0.9% zinc borate, and 0.3% melamine cyanurate; The dispersant comprises 0.3% polycarboxylate dispersant and 0.2% naphthalene sulfonate formaldehyde condensate; The mass ratio of water to magnesium oxysulfate gelling agent is 0.5:1.

[0031] This embodiment also provides a multi-layer fireproof sheath panel, specifically including: Base layer formula: 65% magnesium oxysulfate gelling agent, 1.5% carbon fiber, 3% glass fiber, 3.5% basalt fiber, 12% ultrafine talc powder, 12% heavy calcium carbonate, 2% nano calcium carbonate, 1% citric acid; the mass ratio of water to magnesium oxysulfate gelling agent is 0.4:1. Transition bonding layer formulation: 92% magnesium oxychloride adhesive, 4% KH-550 silane coupling agent, 3% titanate coupling agent, 3% epoxy modified polyurethane, 1.5% organobentonite; the mass ratio of water to magnesium oxychloride adhesive is 0.2:1. Surface protective layer formulation: 80% magnesium oxychloride adhesive, 8% intumescent acrylic fire retardant coating, 6% phosphate ester flame retardant coating, 4% UV-P, 3% 1010, 3% silicon carbide micro powder, 11.5% UV-53; water to magnesium oxychloride adhesive mass ratio 0.3:1.

[0032] This embodiment also provides a method for preparing a multi-layer fireproof sheath, which specifically includes the following steps: S1: Place carbon fiber, glass fiber, and basalt fiber in a drying oven at 80℃ for 2 hours to remove moisture; pre-disperse nano-calcium carbonate, nano-magnesium hydroxide, and silicon carbide micro powder using a high-speed disperser at 3000r / min for 10 minutes; place magnesium oxysulfate gelling agent and magnesium oxychloride adhesive at room temperature for 24 hours to balance humidity; S2: The base layer material, after being mixed with water, is stirred for 15 minutes using a double-spiral mixer at 500 r / min to obtain slurry I with a viscosity of 9000 mPa·s. This slurry is poured into a mold and vibrated at 25 Hz with an amplitude of 0.5 mm for 5 minutes. It is then pre-cured for 3 hours in a pre-curing room at 25℃ and 65% relative humidity. The transition bonding layer material, after being mixed with water, is stirred for 8 minutes using a planetary mixer at 800 r / min to obtain slurry II with a viscosity of 13000 mPa·s. This slurry is applied to the base layer surface using a scraper at a speed of 0.8 m / min and allowed to stand at room temperature for 15 minutes. The core heat insulation and fireproof layer material, after being mixed with water, is stirred for 12 minutes using a plow-type mixer at 300 r / min to obtain a mixture with a bulk density of 180 kg / m³. 3 The material is laid on the surface of the transition bonding layer and compacted with a 0.2MPa, 0.2m / min pressure roller. It is then pre-cured in a pre-curing chamber for 4 hours. The raw material for the surface protective layer is mixed with water and dispersed and stirred at 1500r / min for 20min to obtain slurry III with a viscosity of 7000mPa·s. It is then coated with a spraying device with a diameter of 1.5mm and a pressure of 0.4MPa. After being trimmed with a scraper, it is vibrated at 20Hz and an amplitude of 0.3mm for 2min. S3: Place the mold in a curing room at 30℃ and 70% relative humidity for 8 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product. Example 4:

[0033] This embodiment provides a heat-insulating and fire-resistant layer, specifically comprising the following components by mass fraction: The compound aerogel material comprises 85%, a modified flame retardant synergist comprises 5%, a dispersant comprises 1.5%, and a magnesium oxysulfate gelling agent comprises 30%. The composite aerogel material comprises 55% silica aerogel and 30% zirconia aerogel. The modified flame retardant synergist comprises 3% nano-magnesium hydroxide, 1.5% zinc borate, and 0.5% melamine cyanurate; The dispersant comprises 1.0% polycarboxylate dispersant and 0.5% naphthalene sulfonate formaldehyde condensate; The mass ratio of water to magnesium oxysulfate gelling agent is 0.5:1.

[0034] This embodiment also provides a multi-layer fireproof sheath panel, specifically including: Base layer formula: 65% magnesium oxysulfate gelling agent, 1.5% carbon fiber, 3% glass fiber, 3.5% basalt fiber, 12% ultrafine talc powder, 12% heavy calcium carbonate, 2% nano calcium carbonate, 1% citric acid; the mass ratio of water to magnesium oxysulfate gelling agent is 0.4:1. Transition bonding layer formulation: 92% magnesium oxychloride adhesive, 4% KH-550 silane coupling agent, 3% titanate coupling agent, 3% epoxy modified polyurethane, 1.5% organobentonite; the mass ratio of water to magnesium oxychloride adhesive is 0.2:1. Surface protective layer formulation: 80% magnesium oxychloride adhesive, 8% intumescent acrylic fire retardant coating, 6% phosphate ester flame retardant coating, 4% UV-P, 3% 1010, 3% silicon carbide micro powder, 11.5% UV-53; water to magnesium oxychloride adhesive mass ratio 0.3:1.

[0035] This embodiment also provides a method for preparing a multi-layer fireproof sheath, which specifically includes the following steps: S1: Place carbon fiber, glass fiber, and basalt fiber in a drying oven at 80℃ for 2 hours to remove moisture; pre-disperse nano-calcium carbonate, nano-magnesium hydroxide, and silicon carbide micro powder using a high-speed disperser at 3000r / min for 10 minutes; place magnesium oxysulfate gelling agent and magnesium oxychloride adhesive at room temperature for 24 hours to balance humidity; S2: The base layer material, after being mixed with water, is stirred for 15 minutes using a double-spiral mixer at 500 r / min to obtain slurry I with a viscosity of 9000 mPa·s. This slurry is poured into a mold and vibrated at 25 Hz with an amplitude of 0.5 mm for 5 minutes. It is then pre-cured for 3 hours in a pre-curing room at 25℃ and 65% relative humidity. The transition bonding layer material, after being mixed with water, is stirred for 8 minutes using a planetary mixer at 800 r / min to obtain slurry II with a viscosity of 13000 mPa·s. This slurry is applied to the base layer surface using a scraper at a speed of 0.8 m / min and allowed to stand at room temperature for 15 minutes. The core heat insulation and fireproof layer material, after being mixed with water, is stirred for 12 minutes using a plow-type mixer at 300 r / min to obtain a mixture with a bulk density of 180 kg / m³. 3 The material is laid on the surface of the transition bonding layer and compacted with a 0.2MPa, 0.2m / min pressure roller. It is then pre-cured in a pre-curing chamber for 4 hours. The raw material for the surface protective layer is mixed with water and dispersed and stirred at 1500r / min for 20min to obtain slurry III with a viscosity of 7000mPa·s. It is then coated with a spraying device with a diameter of 1.5mm and a pressure of 0.4MPa. After being trimmed with a scraper, it is vibrated at 20Hz and an amplitude of 0.3mm for 2min. S3: Place the mold in a curing room at 30℃ and 70% relative humidity for 8 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product. Example 5:

[0036] This embodiment provides a heat-insulating and fire-resistant layer, specifically comprising the following components by mass fraction: The compound aerogel material comprises 80%, modified flame retardant synergist 4%, dispersant 1%, and magnesium oxysulfate gelling agent 15%. The composite aerogel material comprises 58% silica aerogel and 22% zirconia aerogel. The modified flame retardant synergist comprises 2.4% nano-magnesium hydroxide, 1.2% zinc borate, and 0.4% melamine cyanurate; The dispersant contains 0.6% polycarboxylate dispersant and 0.4% naphthalene sulfonate formaldehyde condensate. The mass ratio of water to magnesium oxysulfate gelling agent is 0.5:1.

[0037] This embodiment also provides a multi-layer fireproof sheath panel, specifically including: Base layer formula: 65% magnesium oxysulfate gelling agent, 1.5% carbon fiber, 3% glass fiber, 3.5% basalt fiber, 12% ultrafine talc powder, 12% heavy calcium carbonate, 2% metakaolin, 1% citric acid; the mass ratio of water to magnesium oxysulfate gelling agent is 0.4:1. Transition bonding layer formulation: 92% magnesium oxychloride adhesive, 4% KH-550 silane coupling agent, 3% titanate coupling agent, 3% epoxy modified polyurethane, 1.5% organobentonite; the mass ratio of water to magnesium oxychloride adhesive is 0.2:1. Surface protective layer formulation: 80% magnesium oxychloride adhesive, 8% intumescent acrylic fire retardant coating, 6% phosphate ester flame retardant coating, 4% UV-P, 3% 1010, 4% silicon carbide micro powder, 11.5% UV-53; water to magnesium oxychloride adhesive mass ratio 0.3:1.

[0038] This embodiment also provides a method for preparing a multi-layer fireproof sheath, which specifically includes the following steps: S1: Place carbon fiber, glass fiber, and basalt fiber in a drying oven at 80℃ for 2 hours to remove moisture; pre-disperse nano-calcium carbonate, nano-magnesium hydroxide, and silicon carbide micro powder using a high-speed disperser at 3000r / min for 10 minutes; place magnesium oxysulfate gelling agent and magnesium oxychloride adhesive at room temperature for 24 hours to balance humidity; S2: The base layer material, after being mixed with water, is stirred for 15 minutes using a double-spiral mixer at 500 r / min to obtain slurry I with a viscosity of 9000 mPa·s. This slurry is poured into a mold and vibrated at 25 Hz with an amplitude of 0.5 mm for 5 minutes. It is then pre-cured for 4 hours in a pre-curing room at 25℃ and 65% relative humidity. The transition bonding layer material, after being mixed with water, is stirred for 8 minutes using a planetary mixer at 800 r / min to obtain slurry II with a viscosity of 13000 mPa·s. This slurry is applied to the base layer surface using a scraper at a speed of 0.8 m / min and allowed to stand at room temperature for 15 minutes. The core heat insulation and fireproof layer material, after being mixed with water, is stirred for 12 minutes using a plow-type mixer at 300 r / min to obtain a mixture with a bulk density of 180 kg / m³. 3 The material is laid on the surface of the transition bonding layer and compacted with a 0.2MPa, 0.2m / min pressure roller. It is then pre-cured in a pre-curing chamber for 5 hours. The raw material for the surface protective layer is mixed with water and dispersed and stirred at 1500r / min for 20 minutes to obtain slurry III with a viscosity of 7000mPa·s. It is then coated with a spraying device with a diameter of 1.5mm and a pressure of 0.4MPa. After being trimmed with a scraper, it is vibrated at 20Hz and an amplitude of 0.3mm for 2 minutes. S3: Place the mold in a curing room at 28℃ and 75% relative humidity for 9 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product.

[0039] Comparative Example 1: This comparative example provides an insulation layer, which is rock wool with a thickness of 20 mm.

[0040] This comparative example also provides a multi-layer fireproof sheath panel, specifically including: Base layer formulation: 80% magnesium oxysulfate gelling agent, 10% glass fiber, 10% talc powder; base layer thickness is 12mm; the mass ratio of water to magnesium oxysulfate gelling agent is 0.4:1. Surface protective layer formulation: 90% magnesium oxychloride adhesive, 10% intumescent acrylic fire retardant coating; water to magnesium oxychloride adhesive mass ratio 0.3:1.

[0041] This comparative example also provides a method for preparing a multi-layer fireproof sheath, which specifically includes the following steps: S1: Place the glass fiber in a drying oven at 80℃ for 2 hours to remove moisture; place the magnesium oxysulfate gelling agent and magnesium oxychloride adhesive at room temperature for 24 hours to balance the humidity; S2: After adding water to the base material, stir with a double spiral agitator at 500 r / min for 15 min to obtain slurry I with a viscosity of 9000 mPa·s. Pour into a mold and vibrate at 25 Hz and 0.5 mm amplitude for 5 min. Pre-cur in a pre-curing room at 25 ℃ and 65% relative humidity for 2 h. Rock wool is directly pasted onto the base surface. After adding water to the surface protective layer material, disperse and stir at 1500 r / min for 20 min to obtain slurry II with a viscosity of 7000 mPa·s. Apply with a spraying device with a diameter of 1.5 mm and a pressure of 0.4 MPa. After scraping, vibrate at 20 Hz and 0.3 mm amplitude for 2 min. S3: Place the mold in a curing room at 30℃ and 70% relative humidity for 7 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product.

[0042] Comparative Example 2: This comparative example provides a heat-insulating and fire-resistant layer, specifically comprising the following components by mass fraction: The compound aerogel material comprises 80%, modified flame retardant synergist 4%, dispersant 1%, and magnesium oxysulfate gelling agent 15%. The composite aerogel material comprises 58% silica aerogel and 22% zirconia aerogel. The modified flame retardant synergist comprises 2.4% nano-magnesium hydroxide, 1.2% zinc borate, and 0.4% melamine cyanurate; The dispersant contains 0.6% polycarboxylate dispersant and 0.4% naphthalene sulfonate formaldehyde condensate. The mass ratio of water to magnesium oxysulfate gelling agent is 0.5:1.

[0043] This comparative example also provides a multi-layer fireproof sheath panel, specifically including: Base layer formula: 65% magnesium oxysulfate gelling agent, 1.5% carbon fiber, 3% glass fiber, 3.5% basalt fiber, 12% ultrafine talc powder, 12% heavy calcium carbonate, 2% nano calcium carbonate, 1% citric acid; the mass ratio of water to magnesium oxysulfate gelling agent is 0.4:1. Surface protective layer formulation: 80% magnesium oxychloride adhesive, 8% intumescent acrylic fire retardant coating, 6% phosphate ester flame retardant coating, 4% UV-P, 3% 1010, 3% silicon carbide micro powder, 11.5% UV-53; water to magnesium oxychloride adhesive mass ratio 0.3:1.

[0044] This comparative example also provides a method for preparing a multi-layer fireproof sheath, which specifically includes the following steps: S1: Place carbon fiber, glass fiber, and basalt fiber in a drying oven at 80℃ for 2 hours to remove moisture; pre-disperse nano-calcium carbonate, nano-magnesium hydroxide, and silicon carbide micro powder using a high-speed disperser at 3000r / min for 10 minutes; place magnesium oxysulfate gelling agent and magnesium oxychloride adhesive at room temperature for 24 hours to balance humidity; S2: After adding water to the base material, slurry I is obtained by stirring with a double-spiral mixer at 500 r / min for 15 min, with a viscosity of 9000 mPa·s. It is then poured into a mold and vibrated at 25 Hz with an amplitude of 0.5 mm for 5 min, and pre-cured in a pre-curing chamber at 25℃ and 65% relative humidity for 3 h. The core insulation and fireproof layer material is also obtained by adding water to the base material and stirring with a plow-type mixer at 300 r / min for 12 min, with a bulk density of 180 kg / m³. 3 The material is laid on the base surface and compacted with a 0.2MPa, 0.2m / min roller. It is then pre-cured in a pre-curing chamber for 4 hours. The raw material for the surface protective layer is mixed with water and dispersed and stirred at 1500r / min for 20 minutes to obtain slurry II with a viscosity of 7000mPa·s. It is then coated with a spraying device with a diameter of 1.5mm and a pressure of 0.4MPa. After being trimmed with a scraper, it is vibrated at 20Hz and an amplitude of 0.3mm for 2 minutes. S3: Place the mold in a curing room at 30℃ and 70% relative humidity for 8 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product.

[0045] Comparative Example 3: This comparative example provides a heat-insulating and fire-resistant layer, specifically comprising the following components by mass fraction: The compound aerogel material comprises 80% a dispersant, 1% magnesium oxysulfate gelling agent, and 15% magnesium oxysulfate gelling agent. The composite aerogel material contains 80% silica aerogel. The dispersant contains 0.6% polycarboxylate dispersant and 0.4% naphthalene sulfonate formaldehyde condensate. The mass ratio of water to magnesium oxysulfate gelling agent is 0.5:1.

[0046] This comparative example also provides a multi-layer fireproof sheath panel, specifically including: Base layer formula: 65% magnesium oxysulfate gelling agent, 1.5% carbon fiber, 3% glass fiber, 3.5% basalt fiber, 12% ultrafine talc powder, 12% heavy calcium carbonate, 2% nano calcium carbonate, 1% citric acid; the mass ratio of water to magnesium oxysulfate gelling agent is 0.4:1. Transition bonding layer formulation: 92% magnesium oxychloride adhesive, 4% KH-550 silane coupling agent, 3% titanate coupling agent, 3% epoxy modified polyurethane, 1.5% organobentonite; the mass ratio of water to magnesium oxychloride adhesive is 0.2:1. Surface protective layer formulation: 80% magnesium oxychloride adhesive, 8% intumescent acrylic fire retardant coating, 6% phosphate ester flame retardant coating, 4% UV-P, 3% 1010, 3% silicon carbide micro powder, 11.5% UV-53; water to magnesium oxychloride adhesive mass ratio 0.3:1.

[0047] This comparative example also provides a method for preparing a multi-layer fireproof sheath, which specifically includes the following steps: S1: Place carbon fiber, glass fiber, and basalt fiber in a drying oven at 80℃ for 2 hours to remove moisture; pre-disperse nano-calcium carbonate, nano-magnesium hydroxide, and silicon carbide micro powder using a high-speed disperser at 3000r / min for 10 minutes; place magnesium oxysulfate gelling agent and magnesium oxychloride adhesive at room temperature for 24 hours to balance humidity; S2: The base layer material, after being mixed with water, is stirred for 15 minutes using a double-spiral mixer at 500 r / min to obtain slurry I with a viscosity of 9000 mPa·s. This slurry is poured into a mold and vibrated at 25 Hz with an amplitude of 0.5 mm for 5 minutes. It is then pre-cured for 3 hours in a pre-curing room at 25℃ and 65% relative humidity. The transition bonding layer material, after being mixed with water, is stirred for 8 minutes using a planetary mixer at 800 r / min to obtain slurry II with a viscosity of 13000 mPa·s. This slurry is applied to the base layer surface using a scraper at a speed of 0.8 m / min and allowed to stand at room temperature for 15 minutes. The core heat insulation and fireproof layer material, after being mixed with water, is stirred for 12 minutes using a plow-type mixer at 300 r / min to obtain a mixture with a bulk density of 180 kg / m³. 3 The material is laid on the surface of the transition bonding layer and compacted with a 0.2MPa, 0.2m / min pressure roller. It is then pre-cured in a pre-curing chamber for 4 hours. The raw material for the surface protective layer is mixed with water and dispersed and stirred at 1500r / min for 20min to obtain slurry III with a viscosity of 7000mPa·s. It is then coated with a spraying device with a diameter of 1.5mm and a pressure of 0.4MPa. After being trimmed with a scraper, it is vibrated at 20Hz and an amplitude of 0.3mm for 2min. S3: Place the mold in a curing room at 30℃ and 70% relative humidity for 8 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product.

[0048] Test Example 1: This test example is a performance test of the multi-layer fireproof sheathing panels prepared in Examples 1-5 and Comparative Examples 1-3. The specific results are shown in Table 1. Compared with existing technologies (Comparative Example 1): The fire resistance rating of Examples 1-5 was improved from B1 to A. This is due to the use of silica / zirconia composite aerogel to construct a full-temperature-range thermal insulation barrier, and the synergistic flame-retardant system composed of nano-magnesium hydroxide, zinc borate, and MCA, achieving a highly efficient fusion of physical insulation and chemical flame retardancy. The fire resistance limit time was significantly increased from 60 minutes to 116-130 minutes. Because the nanoporous aerogel replaced the fiber structure of traditional rock wool, it greatly hindered heat conduction and convection, significantly reducing the thermal conductivity from 0.038 W / (m·K) to 0.013-0.016 W / (m·K), a reduction of 58%-66%. Due to the multi-element synergistic reinforcement of carbon fiber / glass fiber / basalt fiber and the multi-layered sheath, the interlayer bond strength increased from 0.42 MPa to 1.02-1.12 MPa, an increase of 143%-167%, and the flexural strength increased from 8.5 MPa to 12.6-13.2 MPa. MPa, increased by 48%-55%; due to stable matrix and dense surface protection, 24h water resistance mass loss rate decreased from 3.2% to 0.7%-1.1%, a reduction of 66%-78%; fully demonstrating the advantages of this invention in fire resistance, heat insulation, mechanical properties and durability; comparison with the absence of a transition bonding layer (Comparative Example 2): interlayer bond strength in Examples 1-5 increased from 0.68 MPa to 1.02-1.12 MPa. MPa, an increase of 50% to 65%, mainly due to the lack of coupling agent "bridging effect" and toughening agent stress buffering effect. The interface bonding degenerates from chemical-physical composite effect to fragile mechanical interlocking, proving the key role of the transition bonding layer in interlayer stability. Comparison of single aerogel + no flame retardant synergist (Comparative Example 3): The fire protection time of Examples 1-5 increased from 95 minutes to 116-130 minutes, an extension of 22% to 37%, and the thermal conductivity increased by 13% to 20%. The lack of zirconia aerogel in Comparative Example 3 led to a decrease in high temperature resistance, and the lack of flame retardant synergist weakened the high temperature flame retardant effect, verifying the necessity of the core layer compound design.

[0049] In summary, this invention, through multi-layered structural synergy and formula optimization, is significantly superior to existing technologies and solutions lacking single functions, and has industrial application value.

Claims

1. A heat-insulating and fire-resistant layer, characterized in that, The heat insulation and fireproof layer comprises the following components by mass fraction: 70%-85% compound aerogel material, 3%-5% modified flame retardant synergist, 0.5%-1.5% dispersant, and 10%-30% magnesium oxysulfate gelling agent.

2. The heat-insulating and fire-resistant layer according to claim 1, characterized in that, The heat insulation and fireproof layer comprises the following components by mass fraction: 75%-82% compound aerogel material, 3.8%-4.2% modified flame retardant synergist, 0.8%-1.2% dispersant, and 12%-18% magnesium oxysulfate gelling agent.

3. The heat-insulating and fire-resistant layer according to claim 1 or 2, characterized in that, In the composite aerogel material, the mass fraction of silica aerogel is 50-65% of the heat insulation and fireproof layer, and the mass fraction of zirconia aerogel is 20-35% of the heat insulation and fireproof layer; the bulk density of the silica aerogel is 50-80 kg / m³. 3 The thermal conductivity is ≤0.018 W / (m·K); the bulk density of the zirconia aerogel is 80-120 kg / m³. 3 .

4. The heat-insulating and fire-resistant layer according to claim 1 or 2, characterized in that, The modified flame retardant synergist contains 1.5-3% by mass of nano-magnesium hydroxide, 0.6-1.5% by mass of zinc borate, and 0.3-1% by mass of melamine cyanurate. The nano-magnesium hydroxide has a particle size of 50-100 nm and a decomposition temperature of ≥340℃, and the zinc borate contains ≥98% ZnB2O4.

5. The heat-insulating and fire-resistant layer according to claim 1 or 2, characterized in that, The dispersant contains polycarboxylate dispersant at a mass fraction of 0.3-1.05% of the heat insulation and fireproof layer, and naphthalene sulfonate formaldehyde condensate at a mass fraction of 0.15-0.6% of the heat insulation and fireproof layer; the solid content of the polycarboxylate dispersant is ≥40%.

6. A method for preparing a multi-layer fireproof sheath based on the heat-insulating and fireproof layer according to any one of claims 1-5, characterized in that, Includes the following steps: S1: Dry carbon fiber, glass fiber, basalt fiber; high-speed dispersed nano-calcium carbonate, nano-magnesium hydroxide, silicon carbide micro powder; S2: Prepare the base layer, apply an over-adhesion layer to the base layer, lay a heat-insulating and fireproof layer on the over-adhesion layer, and apply a surface protective layer on the heat-insulating and fireproof layer. S3: Place the mold in a curing room at 25-35℃ and 60%-80% relative humidity for 7-10 days, sprinkling water once a day; after curing, remove the mold and trim the edges to obtain the finished product.

7. The method for preparing the multi-layer fireproof sheathing according to claim 6, characterized in that, The specific steps of S2 are as follows: After adding water to the base layer material, stir with a double-spiral mixer at 500 r / min for 15 minutes to obtain slurry I. Pour into a mold and vibrate at 20-30 Hz and 0.5 mm amplitude for 3-5 minutes. Place in a pre-curing room for pre-curing. After adding water to the transition bonding layer material, stir with a planetary mixer at 800 r / min for 8 minutes to obtain slurry II. Apply to the base layer surface with a scraper at a speed of 0.5-1 m / min and let stand at room temperature for 10-20 minutes. After adding water to the heat insulation and fireproof layer material, stir with a 3... The mixture is stirred for 12 minutes at 00 r / min using a plow-type mixer. It is then spread on the surface of the transition bonding layer, compacted with a roller at 0.1-0.3 MPa and 0.3-0.5 m / min, and placed in a pre-curing chamber for pre-curing. The raw material for the surface protective layer is mixed with water and dispersed and stirred at 1500 r / min for 20 minutes to obtain slurry III. It is then coated with a spraying device with a diameter of 1.5-2 mm and a pressure of 0.3-0.5 MPa. After being trimmed with a scraper, it is vibrated at 15-20 Hz and an amplitude of 0.3 mm for 1-2 minutes.

8. The method for preparing the multi-layer fireproof sheathing according to claim 7, characterized in that, The viscosity of slurry I is 8000-10000 mPa·s, the viscosity of slurry II is 12000-15000 mPa·s, and the bulk density of the mixture is 150-200 kg / m³. 3 The viscosity of slurry III is 6000-8000 mPa·s.

9. The method for preparing the multi-layer fireproof sheathing according to claim 7, characterized in that, The pre-curing chamber conditions are a temperature of 20-25℃ and a relative humidity of 60%-70%; the base layer is pre-cured for 2-4 hours, and the heat insulation and fireproof layer is pre-cured for 3-5 hours.

10. The method for preparing the multi-layer fireproof sheathing according to claim 7, characterized in that, The thickness of the base layer is 8-15mm, the thickness of the transition bonding layer is 1-3mm, the thickness of the heat insulation and fireproof layer is 10-25mm, and the thickness of the surface protective layer is 2-5mm.

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