Fireproof flame-retardant rock wool board and preparation method thereof

Abstract

The invention relates to the field of rock wool boards, and provides a fireproof flame-retardant rock wool board and a preparation method thereof. The fireproof flame-retardant rock wool board is prepared from the following raw materials in parts by weight: 70 to 80 parts of basalt fiber, 10 to 15 parts of paraffin and silicon dioxide phase change microcapsules, 12 to 15 parts of bio-based polyurethane / nano TiO2 binder, 5 to 8 parts of polyimide nanofiber, 2 to 3 parts of zinc borate, 1 to 2 parts of magnesium hydroxide, 0.5 to 1 part of silane coupling agent and 10 to 15 parts of deionized water. According to the fireproof flame-retardant rock wool board provided by the invention, various materials are organically combined by reasonably selecting raw materials and a preparation process, the fireproof flame-retardant rock wool board with excellent comprehensive performance is prepared, and the rock wool board not only has A-grade combustion performance, but also has relatively low heat conductivity coefficient, good thickness stability and relatively high tensile strength; the requirement of the market on a high-performance fireproof flame-retardant material is met.

Description

Technical Field

[0001] The present invention relates to the technical field of rock wool boards, and specifically, to a fireproof and flame-retardant rock wool board and a preparation method thereof. Background Art

[0002] In multiple fields such as construction, transportation, and energy, the application of fireproof and flame-retardant materials is becoming increasingly widespread. Especially in places with extremely high safety requirements, such as high-rise buildings, subways, ships, etc., the use of fireproof and flame-retardant materials is indispensable. As a common fireproof and flame-retardant material, rock wool boards are highly favored due to their excellent heat insulation performance and fireproof performance. However, although traditional rock wool boards do not produce open flames when burning, their flame-retardant performance and thermal stability still need to be further improved to meet higher safety requirements.

[0003] Currently, the rock wool boards on the market mainly improve their fireproof performance by adding inorganic flame retardants, but these flame retardants often affect the mechanical properties and processing properties of the materials. At the same time, traditional rock wool boards also have certain limitations in terms of thermal conductivity, thickness stability, and tensile strength, and it is difficult to meet the high requirements for the comprehensive performance of materials in specific application scenarios.

[0004] In recent years, with the development of nanotechnology and phase change materials, researchers have begun to try to apply these new technologies to the preparation of rock wool boards in order to obtain fireproof and flame-retardant materials with more excellent performance. For example, adding nanoparticles can improve the mechanical properties and thermal stability of the materials; using the energy storage and energy release characteristics of phase change materials can adjust the temperature response of the materials and improve their flame-retardant performance.

[0005] However, there are still some problems with the fireproof and flame-retardant rock wool boards in the prior art. On the one hand, the dispersibility and compatibility of nanoparticles are poor, and it is difficult to be evenly distributed in the rock wool board, which affects the performance of the materials; on the other hand, the selection and encapsulation technology of phase change materials are also key factors restricting their application. Improper phase change materials or encapsulation technology may cause the materials to release harmful gases when burning, and even exacerbate the fire. Based on this, the present invention proposes a fireproof and flame-retardant rock wool board and a preparation method thereof. Summary of the Invention

[0006] The present invention proposes a fireproof and flame-retardant rock wool board and a preparation method thereof, which have excellent flame-retardant performance, good mechanical properties and processing properties, and at the same time also have a low thermal conductivity and high thickness stability.

[0007] The technical solution of the present invention is as follows: In a first aspect, the present invention provides a fireproof and flame-retardant rock wool board, which is composed of the following raw materials in parts by weight: 70-80 parts of basalt fiber, 10-15 parts of paraffin@silica phase change microcapsules, 12-15 parts of bio-based polyurethane / nano-TiO₂ binder, 5-8 parts of polyimide nanofibers, 2-3 parts of zinc borate, 1-2 parts of magnesium hydroxide, 0.5-1 part of silane coupling agent, and 10-15 parts of deionized water.

[0008] As a further technical solution, the preparation method of the paraffin@silica phase change microcapsules includes: heating paraffin to melting, slowly dropping it into an aqueous surfactant solution, and homogenizing and emulsifying to obtain an oil / water emulsion; adding absolute ethanol to the oil / water emulsion, stirring evenly, slowly dropping tetraethyl orthosilicate, and gradually adding ammonia water to adjust the pH to 9-10, and stirring and reacting to form a silica shell layer wrapping paraffin droplets; centrifugally collecting, washing and drying to obtain.

[0009] As a further technical solution, the preparation method of the oil / water emulsion includes: heating 5-10 g of paraffin to melting, dissolving 1-3 g of sodium dodecyl sulfate in 100-200 mL of deionized water to prepare an aqueous surfactant solution; adding the molten paraffin to the aqueous surfactant solution, and emulsifying in a high-speed homogenizer at 10000-20000 rpm for 20-30 min to form an oil / water emulsion.

[0010] As a further technical solution, the weight ratio of paraffin to tetraethyl orthosilicate is 5-10:10-20.

[0011] As a further technical solution, the preparation method of the bio-based polyurethane / nano-TiO₂ binder includes: mixing castor oil and isophorone diisocyanate, and reacting at 70-80 °C for 3-4 h; adding 1,4-butanediol for chain extension to obtain a prepolymer, adding nano-TiO₂ and mixing with the prepolymer, and performing high-speed shear emulsification at a rotation speed of 10000-11000 rpm for 30-40 min to obtain.

[0012] As a further technical solution, the weight ratio of castor oil, isophorone diisocyanate, 1,4-butanediol and nano-TiO₂ is 65-70:22-28:1.5-2.5:15-25.

[0013] As a further technical solution, the preparation method of the polyimide nanofibers includes: dispersing polyimide in an NMP solvent, stirring at 200 - 300 rpm for 25 - 35 min, adding cetyltrimethylammonium bromide as a dispersant, and performing ultrasonic treatment for 2 - 3 h; performing electrospinning under the conditions of a voltage of 25 - 30 kV, a receiving distance of 10 - 15 cm, and a spinning speed of 1 - 1.2 mL / h, and then drying in vacuo at 50 - 60 °C for 10 - 12 h to finally form polyimide nanofibers with a diameter of 100 - 200 nm.

[0014] As a further technical solution, the weight - part ratio of the polyimide, the NMP solvent, and the cetyltrimethylammonium bromide is 20 - 24:90 - 100:0.5 - 1.

[0015] In a second aspect, the present invention provides a preparation method of a fire - proof and flame - retardant rock wool board. The steps include: drying basalt fibers in an oven at 100 - 110 °C for 2 - 3 h for standby, adding a bio - based polyurethane / nano - TiO₂ binder to deionized water, and adding a silane coupling agent, zinc borate, and magnesium hydroxide thereto, performing high - speed shear emulsification, successively adding basalt fibers, polyimide nanofibers, and paraffin@silica phase - change microcapsules, and stirring at 200 - 240 rpm for 10 - 15 min to form a uniform slurry; injecting the slurry into a mold, pre - pressing at a pressure of 0.5 - 1.0 MPa for 5 minutes, then pressing tightly at a pressure of 4 - 6 MPa, curing at a temperature of 70 - 80 °C for 2 - 3 h, and heating to 140 - 150 °C for curing for 40 - 60 min to obtain the fire - proof and flame - retardant rock wool board.

[0016] As a further technical solution, the rate of the high - speed shear emulsification is 8000 - 9000 rpm, and the time is 20 - 30 min.

[0017] The working principle and beneficial effects of the present invention are as follows: The present invention combines various components such as basalt fibers, paraffin@silica phase - change microcapsules, bio - based polyurethane / nano - TiO₂ binders, polyimide nanofibers, zinc borate, and magnesium hydroxide to construct a new fire - proof and flame - retardant rock wool board system. Among them, basalt fibers, as the matrix material, have high thermal stability and good mechanical properties; paraffin@silica phase - change microcapsules absorb heat through phase change, effectively reducing the temperature of the material in a fire; bio - based polyurethane / nano - TiO₂ binders not only provide good bonding performance but also reduce pore blockage through the photocatalytic effect of nano - TiO₂; polyimide nanofibers enhance the mechanical properties and thickness stability of the material.

[0018] In the present invention, zinc borate and magnesium hydroxide are used as flame retardants, which act synergistically with the rock wool matrix to improve the flame retardant performance of the material. When heated, zinc borate and magnesium hydroxide decompose, absorb heat and release water vapor, forming a heat insulation layer to prevent the spread of fire. At the same time, they act synergistically with the basalt fiber matrix to improve the overall flame retardant performance of the material.

[0019] In the present invention, paraffin@silica phase change microcapsules are applied to rock wool boards for the first time. Through the dual effects of phase change energy storage and nano-pores, the thermal conductivity of the material is significantly reduced. Paraffin absorbs a large amount of heat during the phase change process, effectively slowing down the heat transfer; the silica shell layer acts as a heat insulation barrier, further blocking heat conduction. At the same time, the nano-pore structure of the phase change microcapsules also increases the thermal resistance of the material, thereby reducing the thermal conductivity.

[0020] In the present invention, bio-based polyurethane is used as a binder, and nano-TiO2 is added for modification to improve the rigidity and interfacial properties of the binder. This bio-based polyurethane has good environmental protection performance and bonding performance; the addition of nano-TiO2 enhances the rigidity of the binder and improves the tensile strength of the material. At the same time, the dispersion of nano-TiO2 in the binder may affect the microstructure of the binder through its small size effect and interfacial effect, reducing the heat conduction path, thereby indirectly reducing the thermal conductivity. In addition, although the photocatalytic effect of nano-TiO2 is not mainly used for photocatalytic degradation here, its presence may help to improve the heat resistance of the binder and indirectly enhance the overall fire protection performance.

[0021] In the present invention, polyimide nanofibers are prepared by electrospinning technology and applied to rock wool boards, significantly improving the mechanical properties and thickness stability of the material. Polyimide nanofibers have high strength and high modulus, and can form a "bridging" effect to enhance the tensile strength and thickness stability of the material. At the same time, the uniform distribution of nanofibers also helps to improve the overall performance of the material. Detailed implementation mode

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of the present invention.

[0023] It should be noted that in the present invention, the average diameter of basalt fibers is 6μm and the average length is 50mm, purchased from Hebei Huanneng Rock Wool Co., Ltd.; the model of nano-TiO2 is Aeroxide P25; the silane coupling agent is KH550.

[0024] Example 1 In this embodiment, a fireproof and flame-retardant rock wool board is provided, which is composed of the following raw materials in parts by weight: 75 parts of basalt fiber, 12 parts of paraffin@silica phase change microcapsule, 13 parts of bio-based polyurethane / nano-TiO₂ binder, 6 parts of polyimide nanofiber, 2.5 parts of zinc borate, 1.5 parts of magnesium hydroxide, 0.7 part of silane coupling agent, and 13 parts of deionized water; Among them, the preparation method of the paraffin@silica phase change microcapsule includes: heating 7 g of paraffin to melting, dissolving 2 g of sodium dodecyl sulfate in 150 mL of deionized water to prepare an aqueous solution; slowly adding the molten paraffin into the surfactant aqueous solution, and emulsifying in a high-speed homogenizer at 15000 rpm for 25 min to form an oil / water emulsion; Adding 80 mL of absolute ethanol to the oil / water emulsion, stirring evenly, slowly dropping 15 g of tetraethyl orthosilicate, and maintaining the stirring speed at 350 rpm; gradually dropping ammonia water with a mass concentration of 26% to adjust the pH to 9.5, controlling the reaction temperature at 30 °C, and continuously stirring and reacting for 9 hours. Tetraethyl orthosilicate hydrolyzes and condenses to form a silica shell layer to wrap the paraffin droplets; After the reaction is completed, centrifuge at 6000 rpm for 11 min, collect the microcapsules, wash them alternately with deionized water and ethanol 3 times, and dry the product in a vacuum drying oven at 45 °C for 22 hours to obtain white powdery paraffin@silica microcapsules; Among them, the preparation method of the bio-based polyurethane / nano-TiO₂ binder includes: mixing castor oil and isophorone diisocyanate, and reacting at 75 °C for 3.5 h; adding 1,4-butanediol for chain extension to obtain a prepolymer, adding nano-TiO₂ and mixing with the prepolymer, and carrying out high-speed shear emulsification at a rotation speed of 10500 rpm for 35 min to obtain it; the weight ratio of castor oil, isophorone diisocyanate, 1,4-butanediol, and nano-TiO₂ is 67:26:2:20; Among them, the preparation method of the polyimide nanofiber includes: dispersing polyimide in an NMP solvent, stirring at 250 rpm for 30 min, adding cetyltrimethylammonium bromide as a dispersant, and ultrasonic treatment for 2.5 h; carrying out electrospinning under the conditions of a voltage of 27 kV, a receiving distance of 13 cm, and a spinning speed of 1.1 mL / h, and then vacuum drying at 55 °C for 11 h to finally form polyimide nanofibers with a diameter of 150 nm; the weight ratio of polyimide, NMP solvent, and cetyltrimethylammonium bromide is 22:95:0.7; Preparation method of fireproof and flame-retardant rock wool board, the steps include: placing basalt fibers in an oven at 105°C for drying for 2.5 hours for standby, adding bio-based polyurethane / nano-TiO₂ binder to deionized water, and adding silane coupling agent, zinc borate, and magnesium hydroxide thereto, and performing high-speed shear emulsification at a rate of 8500 rpm for 25 min. Then, successively add basalt fibers, polyimide nanofibers (length 30 mm), and paraffin@silica phase change microcapsules, and stir at 220 rpm for 12 min to form a uniform slurry; inject the slurry into a mold, pre-press at a pressure of 0.7 MPa for 5 minutes, then compact under a pressure of 5 MPa, cure at a temperature of 75°C for 2.5 h, and then cure at a temperature of 145°C for 50 min to obtain the fireproof and flame-retardant rock wool board.

[0025] Example 2 In this example, a fireproof and flame-retardant rock wool board is provided, which is composed of the following raw materials in parts by weight: 70 parts of basalt fibers, 10 parts of paraffin@silica phase change microcapsules, 12 parts of bio-based polyurethane / nano-TiO₂ binder, 5 parts of polyimide nanofibers, 2 parts of zinc borate, 1 part of magnesium hydroxide, 0.5 part of silane coupling agent, and 10 parts of deionized water; Among them, the preparation method of paraffin@silica phase change microcapsules includes: heating 5 g of paraffin to melting, dissolving 1 g of sodium dodecyl sulfate in 100 mL of deionized water to prepare an aqueous solution; slowly adding the molten paraffin to the surfactant aqueous solution, and emulsifying in a high-speed homogenizer at 10000 rpm for 20 min to form an oil / water emulsion; Adding 60 mL of absolute ethanol to the oil / water emulsion, stirring evenly, slowly dropping 10 g of tetraethyl orthosilicate, and maintaining the stirring speed at 200 rpm; gradually dropping ammonia water with a mass concentration of 25% to adjust the pH to 9, controlling the reaction temperature at 25°C, and continuously stirring and reacting for 6 hours. Tetraethyl orthosilicate hydrolyzes and condenses to form a silica shell layer to wrap the paraffin droplets; After the reaction is completed, centrifuge at 5000 rpm for 10 min, collect the microcapsules, wash them alternately with deionized water and ethanol 3 times, and dry the product in a vacuum drying oven at 40°C for 20 hours to obtain white powdery paraffin@silica microcapsules; Among them, the preparation method of bio-based polyurethane / nano-TiO₂ binder includes: mixing castor oil and isophorone diisocyanate, and reacting at 70°C for 3 h; adding 1,4-butanediol for chain extension to obtain a prepolymer, adding nano-TiO₂ and mixing with the prepolymer, and performing high-speed shear emulsification at a rotation speed of 10000 rpm for 30 min to obtain; the weight ratio of castor oil, isophorone diisocyanate, 1,4-butanediol, and nano-TiO₂ is 65:22:1.5:15; Among them, the preparation method of polyimide nanofibers includes: dispersing polyimide in NMP solvent, stirring at 200 rpm for 25 min, adding cetyltrimethylammonium bromide as a dispersant, and performing ultrasonic treatment for 2 h; performing electrospinning under the conditions of a voltage of 25 kV, a receiving distance of 10 cm, and a spinning speed of 1 mL / h, and then drying in vacuum at 50 °C for 10 h to finally form polyimide nanofibers with a diameter of 100 nm; the weight ratio of polyimide, NMP solvent, and cetyltrimethylammonium bromide is 20:90:0.5; The preparation method of this fireproof and flame-retardant rock wool board includes the steps of: placing basalt fibers in an oven at 100 °C and drying for 2 h for standby, adding a bio-based polyurethane / nano-TiO₂ binder to deionized water, and adding a silane coupling agent, zinc borate, and magnesium hydroxide thereto, and performing high-speed shear emulsification at a rate of 8000 rpm for 20 min. Then, successively add basalt fibers, polyimide nanofibers (length 30 mm), and paraffin@silica phase change microcapsules, and stir at 200 rpm for 10 min to form a uniform slurry; inject the slurry into a mold, pre-press at a pressure of 0.5 MPa for 5 min, then compact under a pressure of 4 MPa, cure at a temperature of 70 °C for 2 h, and raise the temperature to 140 °C and cure for 40 min to obtain the fireproof and flame-retardant rock wool board.

[0026] Example 3 In this example, a fireproof and flame-retardant rock wool board is provided, which is composed of the following raw materials in parts by weight: 80 parts of basalt fibers, 15 parts of paraffin@silica phase change microcapsules, 15 parts of bio-based polyurethane / nano-TiO₂ binder, 8 parts of polyimide nanofibers, 3 parts of zinc borate, 2 parts of magnesium hydroxide, 1 part of silane coupling agent, and 15 parts of deionized water; Among them, the preparation method of paraffin@silica phase change microcapsules includes: heating 10 g of paraffin to melting, dissolving 3 g of sodium dodecyl sulfate in 200 mL of deionized water to prepare an aqueous solution; slowly adding the molten paraffin to the surfactant aqueous solution, and emulsifying in a high-speed homogenizer at 20000 rpm for 30 min to form an oil / water emulsion; Adding 100 mL of absolute ethanol to the oil / water emulsion, stirring evenly, slowly dropping 20 g of tetraethyl orthosilicate, and maintaining the stirring speed at 500 rpm; gradually dropping ammonia water with a mass concentration of 28% to adjust the pH to 10, controlling the reaction temperature at 35 °C, and continuously stirring and reacting for 12 h, and tetraethyl orthosilicate hydrolyzes and condenses to form a silica shell layer to wrap the paraffin droplets; After the reaction is completed, centrifuge at 8000 rpm for 12 min, collect the microcapsules, wash them alternately with deionized water and ethanol 3 times, and dry the product in a vacuum drying oven at 50 °C for 24 h to obtain white powdery paraffin@silica microcapsules; Among them, the preparation method of the bio-based polyurethane / nano-TiO₂ binder includes: mixing castor oil and isophorone diisocyanate, reacting at 80 °C for 4 h; adding 1,4-butanediol for chain extension to obtain a prepolymer, adding nano-TiO₂ and mixing with the prepolymer, and performing high-speed shear emulsification at a rotation speed of 11,000 rpm for 40 min to obtain it; the weight ratio of castor oil, isophorone diisocyanate, 1,4-butanediol and nano-TiO₂ is 70:28:2.5:25; Among them, the preparation method of polyimide nanofibers includes: dispersing polyimide in NMP solvent, stirring at 300 rpm for 35 min, adding cetyltrimethylammonium bromide as a dispersant, and performing ultrasonic treatment for 3 h; performing electrospinning at a voltage of 30 kV, a receiving distance of 15 cm, and a spinning speed of 1.2 mL / h, and then drying in vacuum at 60 °C for 12 h to finally form polyimide nanofibers with a diameter of 200 nm; the weight ratio of polyimide, NMP solvent and cetyltrimethylammonium bromide is 24:100:1; The preparation method of this fireproof and flame-retardant rock wool board includes the steps of: placing basalt fibers in an oven at 110 °C and drying for 3 hours for standby, adding the bio-based polyurethane / nano-TiO₂ binder to deionized water, and adding silane coupling agent, zinc borate, and magnesium hydroxide thereto, performing high-speed shear emulsification at a rate of 9000 rpm for 30 min, sequentially adding basalt fibers, polyimide nanofibers (length 30 mm) and paraffin@silica phase change microcapsules, and stirring at 240 rpm for 15 min to form a uniform slurry; injecting the slurry into a mold, pre-pressing at a pressure of 1.0 MPa for 5 minutes, then compacting under a pressure of 6 MPa, curing at a temperature of 80 °C for 3 h, and raising the temperature to 150 °C and curing for 60 min to obtain the fireproof and flame-retardant rock wool board.

[0027] Example 4 In this example, a fireproof and flame-retardant rock wool board is provided, which is composed of the following raw materials in parts by weight: 70 parts of basalt fibers, 15 parts of paraffin@silica phase change microcapsules, 12 parts of bio-based polyurethane / nano-TiO₂ binder, 8 parts of polyimide nanofibers, 2 parts of zinc borate, 2 parts of magnesium hydroxide, 0.5 part of silane coupling agent and 15 parts of deionized water; Among them, the preparation method of the paraffin@silica phase change microcapsules includes: heating 5 g of paraffin to melting, dissolving 3 g of sodium dodecyl sulfate in 100 mL of deionized water to prepare an aqueous solution; slowly adding the molten paraffin to the surfactant aqueous solution, and emulsifying in a high-speed homogenizer at 10,000 rpm for 30 min to form an oil / water emulsion; Add 60 mL of absolute ethanol to the oil / water emulsion, stir evenly, slowly dropwise add 20 g of tetraethyl orthosilicate, and maintain the stirring speed at 200 rpm; dropwise add ammonia water with a mass concentration of 28% to adjust the pH to 9, control the reaction temperature at 25 °C, continuously stir and react for 12 hours, and tetraethyl orthosilicate hydrolyzes and condenses to form a silica shell layer to wrap the paraffin droplets; After the reaction is completed, centrifuge at 5000 rpm for 12 min, collect the microcapsules, wash them alternately with deionized water and ethanol 3 times, and dry the product in a vacuum drying oven at 40 °C for 24 hours to obtain white powdery paraffin@silica microcapsules; Among them, the preparation method of the bio-based polyurethane / nano-TiO₂ binder includes: mixing castor oil and isophorone diisocyanate, reacting at 70 °C for 4 h; adding 1,4-butanediol for chain extension to obtain a prepolymer, adding nano-TiO₂ and mixing with the prepolymer, and performing high-speed shear emulsification at a rotation speed of 10000 rpm for 30 min to obtain; the weight ratio of castor oil, isophorone diisocyanate, 1,4-butanediol and nano-TiO₂ is 70:22:2.5:15; Among them, the preparation method of polyimide nanofibers includes: dispersing polyimide in NMP solvent, stirring at 300 rpm for 25 min, adding cetyltrimethylammonium bromide as a dispersant, and performing ultrasonic treatment for 3 h; performing electrospinning at a voltage of 25 kV, a receiving distance of 15 cm, and a spinning speed of 1 mL / h, and then vacuum drying at 60 °C for 10 h to finally form polyimide nanofibers with a diameter of 200 nm; the weight ratio of polyimide, NMP solvent and cetyltrimethylammonium bromide is 20:100:0.5; The preparation method of this fireproof and flame-retardant rock wool board includes the steps: placing basalt fibers in an oven at 110 °C and drying for 2 hours for standby, adding the bio-based polyurethane / nano-TiO₂ binder to deionized water, and adding silane coupling agent, zinc borate and magnesium hydroxide thereto, performing high-speed shear emulsification at a rate of 9000 rpm for 20 min, sequentially adding basalt fibers, polyimide nanofibers (length 30 mm) and paraffin@silica phase change microcapsules, stirring at 240 rpm for 10 min to form a uniform slurry; injecting the slurry into a mold, pre-pressing at a pressure of 1.0 MPa for 5 minutes, then pressing tightly at a pressure of 6 MPa, and curing at a temperature of 70 °C for 3 h, and then heating to 140 °C and curing for 60 min to obtain the fireproof and flame-retardant rock wool board.

[0028] Comparative Example 1 Based on Example 1 with adjustments, different from Example 1, in Comparative Example 1, paraffin@silica is replaced with silica.

[0029] Comparative Example 2 Based on Example 1, with the adjustment that, different from Example 1, paraffin@silica phase change microcapsules were not added in Comparative Example 2.

[0030] Comparative Example 3 Based on Example 1, with the adjustment that, different from Example 1, the bio-based polyurethane / nano-TiO2 binder in Comparative Example 3 was replaced with bio-based polyurethane, that is, nano-TiO2 was not added during the preparation of the bio-based polyurethane / nano-TiO2 binder.

[0031] Comparative Example 4 Based on Example 1, with the adjustment that, different from Example 1, the polyimide nanofibers in Comparative Example 4 were replaced with commercially available polyimide (model PI-2611).

[0032] Comparative Example 5 Based on Example 1, with the adjustment that, different from Example 1, polyimide nanofibers were not added in Comparative Example 5.

[0033] Test Example 1: The fireproof and flame-retardant rock wool boards (with a thickness of 150 mm and a density of 140 kg / m 3 ) prepared in the aforementioned Examples 1-4 and Comparative Examples 1-5 were tested as follows: Combustion performance: The combustion performance was tested with reference to GB 8624-2012 "Classification of the combustion performance of building materials and products"; Thermal conductivity: The test was carried out with reference to GB / T 10294; Thickness stability: The test was carried out with reference to GB / T 8811; Tensile strength perpendicular to the surface: The test was carried out with reference to GB / T30804-2014 "Determination of the tensile strength perpendicular to the surface of thermal insulation products for building use"; The results are shown in Table 1 below: Table 1

[0034] As can be seen from the foregoing, all the examples and comparative examples meet the Class A non-combustibility standard (GB 8624-2012), indicating that the synergistic effect of the zinc borate / magnesium hydroxide flame retardant system and the rock wool matrix is stable and effective, and the fire resistance can still be maintained even when some components are adjusted. Examples 1-4: The thermal conductivity is 0.022-0.026 W / (m·K), which is significantly better than that of traditional rock wool (0.040 W / (m·K)). The paraffin@silica phase change microcapsules absorb heat through phase change and block heat conduction through nano-pores, which is the key to reducing the thermal conductivity. The thermal conductivity of Comparative Example 1 increased to 0.038 W / (m·K), and the lack of phase change energy storage led to a decrease in thermal resistance; the thermal conductivity of Comparative Example 2 further increased to 0.045 W / (m·K), verifying the necessity of the phase change material. The thermal conductivity of Comparative Example 3 slightly increased to 0.028 W / (m·K), and the photocatalytic effect of TiO2 can reduce pore blockage, indirectly optimizing the thermal insulation performance.

[0035] In addition, the thickness change of Examples 1-4 is ≤0.4%, which is attributed to the toughening effect of polyimide nanofibers and the thermal stress buffering of phase change microcapsules. The thickness stability of Comparative Examples 1 / 2 deteriorated to 1.2-1.5%, and deformation was caused by the difference in thermal expansion coefficient. The thickness change of Comparative Examples 4 / 5 increased to 0.7-1.0%, indicating that fiber reinforcement is crucial for suppressing shrinkage. The tensile strength of Examples 1-4 is 145-150 MPa, and the synergistic strengthening effect of polyimide nanofibers and nano-TiO2 is significant. The strength of Comparative Example 3 decreased to 120 MPa because TiO2 can increase the rigidity of the binder. The strength of Comparative Examples 4 / 5 decreased to 80-105 MPa, proving that the "bridging" effect of nanofibers is irreplaceable.

[0036] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fire-retardant rock wool board, characterized in that: It is composed of the following raw materials in parts by weight: 70-80 parts of basalt fiber, 10-15 parts of paraffin@silicon dioxide phase change microcapsules, 12-15 parts of bio-based polyurethane / nano-TiO2 binder, 5-8 parts of polyimide nanofiber, 2-3 parts of zinc borate, 1-2 parts of magnesium hydroxide, 0.5-1 parts of silane coupling agent and 10-15 parts of deionized water.

2. The fireproof and flame-retardant rock wool board according to claim 1, characterized in that: The preparation method of the paraffin@silica phase change microcapsules comprises: heating paraffin to melt, slowly dropping it into a surfactant aqueous solution, homogenizing and emulsifying to obtain an oil / water emulsion; adding anhydrous ethanol to the oil / water emulsion, stirring evenly, slowly dropping ethyl orthosilicate, and adding ammonia water dropwise to adjust the pH to 9-10, stirring and reacting to form a silica shell layer to wrap the paraffin droplets; and collecting by centrifugation, washing and drying to obtain the microcapsules.

3. The fireproof and flame retardant rock wool board according to claim 2, characterized in that: The preparation method of the oil / water emulsion comprises: heating 5-10 g of paraffin wax until it is melted, dissolving 1-3 g of sodium dodecyl sulfate in 100-200 mL of deionized water to prepare a surfactant aqueous solution; adding the molten paraffin wax to the surfactant aqueous solution, and emulsifying in a high-speed homogenizer at 10000-20000 rpm for 20-30 minutes to form an oil / water emulsion.

4. The fireproof and flame retardant rock wool board according to claim 2, characterized in that: The weight ratio of the paraffin wax to ethyl orthosilicate is 5-10:10-20.

5. The fireproof and flame retardant rock wool board according to claim 1, characterized in that: The preparation method of the bio-based polyurethane / nano-TiO2 binder comprises: mixing castor oil and isophorone diisocyanate, reacting at 70-80°C for 3-4h; adding 1,4-butanediol to extend the chain to obtain a prepolymer, adding nano-TiO2 to mix with the prepolymer, and performing high-speed shear emulsification at a rotation speed of 10000-11000rpm for 30-40min to obtain the binder.

6. The fireproof and flame retardant rock wool board according to claim 5, characterized in that: The weight ratio of castor oil, isophorone diisocyanate, 1,4-butanediol and nano-TiO2 is 65-70:22-28:1.5-2.5:15-25.

7. The fireproof and flame retardant rock wool board according to claim 1, characterized in that: The preparation method of the polyimide nanofiber comprises: dispersing polyimide in NMP solvent, stirring at 200-300 rpm for 25-35 min, adding hexadecyltrimethylammonium bromide as a dispersant, and ultrasonically treating for 2-3 h; performing electrostatic spinning at a voltage of 25-30 kV, a receiving distance of 10-15 cm, and a spinning speed of 1-1.2 mL / h, and then vacuum drying at 50-60° C. for 10-12 h, finally forming polyimide nanofibers with a diameter of 100-200 nm.

8. The fireproof and flame retardant rock wool board according to claim 7, characterized in that: The weight ratio of the polyimide, NMP solvent and hexadecyltrimethylammonium bromide is 20-24:90-100:0.5-1.

9. A method for preparing a fireproof and flame-retardant rock wool board according to any one of claims 1 to 8, characterized in that the steps include: The basalt fiber is placed in an oven at 100-110°C and dried for 2-3 hours for later use; a bio-based polyurethane / nano-TiO2 binder is added to deionized water, and a silane coupling agent, zinc borate, and magnesium hydroxide are added thereto, high-speed shear emulsification is performed, and basalt fiber, polyimide nanofiber, and paraffin@silica phase change microcapsule are added in sequence, and stirred at 200-240 rpm for 10-15 minutes to form a uniform slurry; the slurry is injected into a mold, pre-pressed at a pressure of 0.5-1.0 MPa, and then compacted at a pressure of 4-6 MPa, cured at a temperature of 70-80°C for 2-3 hours, and cured at a temperature of 140-150°C for 40-60 minutes to obtain the fire-retardant rock wool board.

10. The method for preparing the fireproof and flame retardant rock wool board according to claim 9, characterized in that: The high-speed shear emulsification rate is 8000-9000 rpm, and the time is 20-30 min.

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