High-strength fireproof door core material and preparation method thereof

Abstract

The application discloses a kind of high-strength fire door core material and preparation method thereof, belong to fire door core material preparation technical field.The preparation method of the high-strength fire door core material, comprising the following steps: step one: composite heat insulation material is dried, then spray coating contains silane coupling agent ethanol solution, while to expanded perlite is dried, then after pretreatment, composite heat insulation material, expanded perlite and glass fiber are added to stirrer, mixed, obtain mixed material;Step two: fire-retardant adhesive is added to mixed material, stir, then add to mold, vibration exhaust, solidification, cutting, obtain high-strength fire door core material.Fire door core material prepared by the method has excellent fire-retardant, heat-insulating, fireproof performance and strength.

Description

Technical Field

[0001] This invention belongs to the field of fireproof door core material preparation technology, specifically relating to a high-strength fireproof door core material and its preparation method. Background Technology

[0002] With the acceleration of urbanization and the large-scale development of high-rise buildings and large public facilities, building fire safety has become a major global issue. As a core component of building fire compartmentation systems, fire doors play a crucial role in preventing the spread of fire, delaying the diffusion of smoke, and buying precious time for evacuation and fire rescue. In recent years, fire accidents have occurred frequently worldwide, especially in high-rise buildings. Due to the rapid spread of fire, short escape windows, and severe property damage, more stringent requirements have been placed on the performance of fire doors. Traditional fire door core materials are mainly inorganic materials such as expanded perlite, vermiculite, and aluminum silicate fiber. Although they can meet the basic fire resistance requirements, their defects such as insufficient mechanical properties, rapid decay of thermal insulation performance, and weak resistance to blast impacts have gradually become apparent. Especially under extreme fire conditions, traditional core materials are prone to structural collapse, thermal insulation failure, and even door deformation and detachment due to high temperatures, seriously threatening the reliability of fire compartments. Therefore, there is an urgent need to develop a new type of fire door core material that combines high strength, high flame retardancy, and long-term thermal insulation performance.

[0003] Patent CN108275951A discloses a high-strength green fireproof door core and its preparation method. The high-strength green fireproof door core comprises the following components in the indicated mass ratios: 400-800 parts aluminate cement, 300-450 parts ceramsite, 2-5 parts fiber, 1-2 parts sodium polyacrylate particles, and 64-160 parts water. When the sodium polyacrylate particles are mixed with aluminate cement, ceramsite, and fiber, they absorb a large amount of water, expanding in volume to tens to hundreds of times their original size. After the primary product is dried, the water is released, causing the particles to shrink and form numerous closed pores. The ceramsite has a honeycomb-like internal structure, characterized by low density, low thermal conductivity, and high strength. Combined with aluminate cement, it can significantly improve the impact resistance of the fireproof door core. However, there is still room for improvement in the heat insulation, flame retardancy, and strength of the fireproof door core prepared by this method. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength fireproof door core material and its preparation method, which solves the technical problems of poor heat insulation, flame retardancy and strength of existing fireproof door core materials.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a method for preparing a high-strength fireproof door core material, comprising the following steps:

[0007] Step 1: Dry the composite insulation material, then spray it with an ethanol solution containing silane coupling agent, and at the same time dry the expanded perlite. Then add the pretreated composite insulation material, expanded perlite and glass fiber into a mixer and mix to obtain a mixture.

[0008] Step 2: Add the flame-retardant adhesive to the mixture, stir, then pour it into the mold, vibrate to remove air, cure, and cut to obtain high-strength fireproof door core material.

[0009] Preferably, in step one, the ratio of the amount of pretreated composite thermal insulation material, expanded perlite and glass fiber is (50-70)g:(15-23)g:(10-18)g; in step two, the ratio of the amount of flame retardant adhesive and mixture is (26-38)g:(78-92)g.

[0010] Preferably, the method for preparing the composite thermal insulation material includes the following steps:

[0011] Q1: Add 1-bromododecane and dimethylaminoethanol to a container, then add acetone, heat and stir to react. After the reaction is complete, cool, filter under reduced pressure, recrystallize, and dry under vacuum to obtain the product; add alumina particles to a container containing deionized water, stir at room temperature, then add the product, urea and hydrochloric acid, and continue stirring to obtain mixed solution 1.

[0012] Q2: Add methyltrimethoxysilane and dimethoxydimethylsilane to mixed solution 1, stir and mix, seal, put into an oven, then add ethanol to the container, continue to put in the oven, dry, calcine, and obtain composite heat insulation material.

[0013] In the above process, 1-bromododecane and dimethylaminoethanol undergo a substitution reaction to obtain the product. The product can then be adsorbed onto the surface of alumina particles by electrostatic interaction to obtain mixed solution 1. Then, methyltrimethoxysilane and dimethoxydimethylsilane are added to mixed solution 1 and undergo a hydrolysis reaction, which in turn leads to a condensation reaction on the surface of alumina to form a substance containing siloxane bonds. Finally, after calcination, a composite thermal insulation material with a three-dimensional structure is obtained.

[0014] Preferably, in Q1, the ratio of 1-bromododecane, dimethylaminoethanol, and acetone is (20-31.2) g : (11.21-15.42) g : (60-80) mL, the heating and stirring reaction temperature is 60-64℃, and the reaction time is 6-8 h; the ratio of alumina particles, deionized water, product, urea, and hydrochloric acid is (0.08-0.32) g : (17-20) mL : (0.3-0.5) g : (10-15) g : (7-9) μL, the stirring time at room temperature is 5-8 h, and the stirring time is continued for 30-45 min.

[0015] Preferably, in Q2, the ratio of methyltrimethoxysilane, dimethoxydimethylsilane and mixed solution 1 is (6-8) mL:(1.91-2.03) mL:(24-29) mL, the stirring time is 2-4 h, the oven temperature is 80-85 °C, after adding ethanol, the oven temperature is maintained at 80-83 °C for 48-52 h, and then maintained at 60-65 °C for 70-75 h, the ethanol is replaced every 8-10 h, the calcination temperatures are 200 °C, 400 °C and 600 °C respectively, and the heating rate is 5 °C / min.

[0016] Preferably, the method for preparing the flame-retardant adhesive includes the following steps:

[0017] S1: Under low temperature conditions, morpholine aqueous solution was slowly added to a mixture of cyanuric chloride and acetone, and the mixture was stirred at low temperature. Then, sodium carbonate aqueous solution was added dropwise, and the mixture was stirred at low temperature for a longer period of time. After the reaction was completed, the mixture was washed and dried to obtain intermediate 1.

[0018] S2: Add 80% hydrazine hydrate to intermediate 1, heat and stir to react. After the reaction is complete, cool, filter, wash and dry to obtain intermediate 2.

[0019] S3: Add intermediate 2 to a container containing dimethylacetamide, then add dicyclohexylmethane diisocyanate and dibutyltin dilaurate. Heat the mixture under an argon atmosphere to obtain a prepolymer. Add hydroxyl-terminated polydimethylsiloxane to the dimethylacetamide, then add it dropwise to the prepolymer. Heat the mixture to react. After the reaction is complete, dry the mixture to obtain a flame-retardant adhesive.

[0020] The synthesis reaction formula for the flame-retardant adhesive in the above process is as follows:

[0021]

[0022] The mass spectrometry analysis results of intermediate 1 were: m / z: 234.01 (100.0%), 236.00 (63.9%), 238.00 (10.3%), 235.01 (7.7%), 237.01 (4.9%), 235.00 (1.5%); the mass spectrometry analysis results of intermediate 2 were: m / z: 226.13 (100.0%), 227.13 (10.6%).

[0023] Preferably, in step S1, the ratio of the amounts of morpholine aqueous solution, cyanuric chloride, acetone, and sodium carbonate aqueous solution is (25-32) mL : (6.12-6.93) g : (140-160) mL : (35-40) mL, the concentration of the morpholine aqueous solution is 0.23 g / mL, the low-temperature environment temperature is -18 to -20℃, the low-temperature stirring reaction temperature is -18 to -20℃, the time is 1-2 h, the concentration of the sodium carbonate aqueous solution is 0.13 g / mL, and the low-temperature stirring reaction continues at -18 to -20℃ for 1-2 h.

[0024] Preferably, in S2, the ratio of intermediate 1 to 80% hydrazine hydrate is (1.5-2.3) g: (90-110) mL, the heating and stirring reaction temperature is 70-73℃, and the reaction time is 10-14 h.

[0025] Preferably, in step S3, the molar ratio of intermediate 2 to dicyclohexylmethane diisocyanate is (0.8-1.2):(0.82-1.21), the heating reaction temperature is 60-80℃, the reaction time is 1-2h, the amount ratio of hydroxyl-terminated polydimethylsiloxane, dimethylacetamide and prepolymer is (0.43-0.52)g:(10-12)mL:(8.01-10.23)g, the heating reaction temperature is 50-60℃, and the reaction time is 1-4h.

[0026] High-strength fireproof door core material is prepared using the aforementioned method.

[0027] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0028] 1. In the process of preparing fireproof door core material, the present invention adds composite heat insulation material and flame retardant adhesive, which can effectively improve the flame retardant performance, fire resistance, heat insulation performance and strength of fireproof door core material.

[0029] 2. This invention adds the prepared composite thermal insulation material to the core material of fireproof doors, which can effectively improve its thermal insulation performance, fire resistance performance and strength. The synergistic effect of alumina and organosilicon structure can effectively prevent heat transfer, and the nanoscale porous structure can reduce the transfer of heat radiation and improve its thermal insulation performance. At the same time, the synergistic effect of organosilicon and alumina can enhance fire resistance performance, and the organosilicon structure can also enhance the bonding force between alumina particles and improve strength.

[0030] 3. This invention adds the prepared flame-retardant adhesive to the fireproof door core material, which can effectively improve its flame-retardant performance and strength. The triazine structure contained in the flame-retardant adhesive can release non-flammable gas and dilute the concentration of flammable gas when a fire occurs. It can also form a carbonized layer on the material surface to prevent the spread of fire and improve the flame-retardant performance of the fireproof door core material. The active groups contained therein can be chemically bonded to the components in the fireproof door core material to improve the bonding strength, make the bonding between the various parts of the core material tighter, and improve its overall strength. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1: This example discloses a method for preparing a composite thermal insulation material, including the following steps:

[0033] Q1: 25.6 g of 1-bromododecane and 13.32 g of dimethylaminoethanol were added to a container, followed by 70 mL of acetone. The mixture was heated and stirred at 62 °C for 6 h. After the reaction was completed, the mixture was cooled, filtered under reduced pressure, recrystallized, and dried under vacuum to obtain the product. 0.2 g of alumina particles were added to a container containing 18.5 mL of deionized water and stirred at room temperature for 6 h. Then, 0.4 g of the product, 12.5 g of urea, and 8 μL of 1 mol / L hydrochloric acid were added, and the mixture was stirred for another 30 min to obtain mixed solution 1.

[0034] Q2: Add 7 mL of methyltrimethoxysilane and 1.97 mL of dimethoxydimethylsilane to 26.5 mL of mixed solution 1, stir and mix for 4 h, seal, and place in an 80 °C oven. Then add ethanol to the container and continue to place it in the oven. Maintain the oven temperature at 80 °C for 48 h, and then at 60 °C for 72 h. Replace the ethanol every 8-10 h. Calcinate at 200 °C, 400 °C, and 600 °C with a heating rate of 5 °C / min to obtain the composite thermal insulation material.

[0035] This embodiment discloses a method for preparing a flame-retardant adhesive, including the following steps:

[0036] S1: At a low temperature of -20℃, 28.5 mL of morpholine aqueous solution with a concentration of 0.23 g / mL was slowly added to a mixture of 6.52 g of cyanuric chloride and 150 mL of acetone. The mixture was stirred at -20℃ for 2 h. Then, 37.5 mL of sodium carbonate aqueous solution with a concentration of 0.13 g / mL was added dropwise. The mixture was stirred at -20℃ for another 2 h. After the reaction was completed, the mixture was washed and dried to obtain intermediate 1.

[0037] S2: Add 100 mL of 80% hydrazine hydrate to 1.9 g of intermediate 1, heat and stir at 72 °C for 12 h. After the reaction is complete, cool, filter, wash and dry to obtain intermediate 2.

[0038] S3: Add 2.38g of intermediate 2 to a container containing 10mL of dimethylacetamide, then add 2.62g of dicyclohexylmethane diisocyanate and 0.02g of dibutyltin dilaurate. Under an argon atmosphere, heat at 75℃ for 2h to obtain a prepolymer. Add 0.47g of hydroxyl-terminated polydimethylsiloxane to 11mL of dimethylacetamide, then add dropwise to 9.11g of the prepolymer. Heat at 60℃ for 4h. After the reaction is complete, dry to obtain a flame-retardant adhesive.

[0039] This embodiment discloses a method for preparing a high-strength fireproof door core material, including the following steps:

[0040] Step 1: Dry the composite thermal insulation material, then spray it with an ethanol solution containing silane coupling agent, and at the same time dry the expanded perlite. Then add 6.0 kg of pretreated composite thermal insulation material, 1.9 kg of expanded perlite and 1.4 kg of glass fiber into a mixer and mix to obtain a mixture.

[0041] Step 2: Add 3.2kg of flame-retardant adhesive to 8.5kg of mixture, stir, then pour into a mold, vibrate to remove air, cure, and cut to obtain high-strength fireproof door core material.

[0042] Example 2: This example discloses a method for preparing a composite thermal insulation material, including the following steps:

[0043] Q1: Add 20g of 1-bromododecane and 11.2g of dimethylaminoethanol to a container, then add 80mL of acetone, heat and stir at 62℃ for 6h. After the reaction is complete, cool, filter under reduced pressure, recrystallize, and dry under vacuum to obtain the product; add 0.08g of alumina particles to a container containing 17mL of deionized water, stir at room temperature for 6h, then add 0.5g of the product, 10g of urea and 7μL of 1mol / L hydrochloric acid, and continue stirring for 30min to obtain mixed solution 1;

[0044] Q2: Add 6 mL of methyltrimethoxysilane and 1.91 mL of dimethoxydimethylsilane to 29 mL of mixed solution 1, stir and mix for 4 h, seal, and place in an 80 °C oven. Then add ethanol to the container and continue to place it in the oven. Maintain the oven temperature at 80 °C for 48 h, and then at 60 °C for 72 h. Replace the ethanol every 8-10 h. Calcinate at 200 °C, 400 °C, and 600 °C with a heating rate of 5 °C / min to obtain the composite thermal insulation material.

[0045] This embodiment discloses a method for preparing a flame-retardant adhesive, including the following steps:

[0046] S1: At a low temperature of -20℃, 25 mL of morpholine aqueous solution with a concentration of 0.23 g / mL was slowly added to a mixture of 6.12 g of cyanuric chloride and 140 mL of acetone. The mixture was stirred at -20℃ for 2 h. Then, 35 mL of sodium carbonate aqueous solution with a concentration of 0.13 g / mL was added dropwise. The mixture was stirred at -20℃ for another 2 h. After the reaction was completed, the mixture was washed and dried to obtain intermediate 1.

[0047] S2: Add 110 mL of 80% hydrazine hydrate to 1.5 g of intermediate 1, heat and stir at 72 °C for 12 h. After the reaction is complete, cool, filter, wash and dry to obtain intermediate 2.

[0048] S3: Add 1.81g of intermediate 2 to a container containing 10mL of dimethylacetamide, then add 2.15g of dicyclohexylmethane diisocyanate and 0.02g of dibutyltin dilaurate. Under an argon atmosphere, heat at 75℃ for 2h to obtain a prepolymer. Add 0.43g of hydroxyl-terminated polydimethylsiloxane to 10mL of dimethylacetamide, then add dropwise to 8.01g of the prepolymer. Heat at 60℃ for 4h. After the reaction is complete, dry to obtain a flame-retardant adhesive.

[0049] This embodiment discloses a method for preparing a high-strength fireproof door core material, including the following steps:

[0050] Step 1: Dry the composite insulation material, then spray it with an ethanol solution containing silane coupling agent, and at the same time dry the expanded perlite. Then add 5.0 kg of pretreated composite insulation material, 1.5 kg of expanded perlite and 1.8 kg of glass fiber into a mixer and mix to obtain a mixture.

[0051] Step 2: Add 2.6kg of flame-retardant adhesive to 7.8kg of mixture, stir, then pour into a mold, vibrate to remove air, cure, and cut to obtain high-strength fireproof door core material.

[0052] Example 3: This example discloses a method for preparing a composite thermal insulation material, including the following steps:

[0053] Q1: 31.2 g of 1-bromododecane and 15.42 g of dimethylaminoethanol were added to a container, followed by 60 mL of acetone. The mixture was heated and stirred at 62 °C for 6 h. After the reaction was completed, the mixture was cooled, filtered under reduced pressure, recrystallized, and dried under vacuum to obtain the product. 0.32 g of alumina particles were added to a container containing 20 mL of deionized water and stirred at room temperature for 6 h. Then, 0.3 g of the product, 15 g of urea, and 9 μL of 1 mol / L hydrochloric acid were added, and the mixture was stirred for another 30 min to obtain mixed solution 1.

[0054] Q2: Add 8 mL of methyltrimethoxysilane and 2.03 mL of dimethoxydimethylsilane to 24 mL of mixed solution 1, stir and mix for 4 h, seal, and place in an 80 °C oven. Then add ethanol to the container and continue to place it in the oven. Maintain the oven temperature at 80 °C for 48 h, and then at 60 °C for 72 h. Replace the ethanol every 8-10 h. Calcinate at 200 °C, 400 °C, and 600 °C with a heating rate of 5 °C / min to obtain the composite thermal insulation material.

[0055] This embodiment discloses a method for preparing a flame-retardant adhesive, including the following steps:

[0056] S1: At a low temperature of -20℃, 32 mL of morpholine aqueous solution with a concentration of 0.23 g / mL was slowly added to a mixture of 6.93 g of cyanuric chloride and 160 mL of acetone. The mixture was stirred at -20℃ for 2 h. Then, 40 mL of sodium carbonate aqueous solution with a concentration of 0.13 g / mL was added dropwise. The mixture was stirred at -20℃ for another 2 h. After the reaction was completed, the mixture was washed and dried to obtain intermediate 1.

[0057] S2: Add 90 mL of 80% hydrazine hydrate to 2.3 g of intermediate 1, heat and stir at 72 °C for 12 h. After the reaction is complete, cool, filter, wash and dry to obtain intermediate 2.

[0058] S3: Add 2.72g of intermediate 2 to a container containing 10mL of dimethylacetamide, then add 2.17g of dicyclohexylmethane diisocyanate and 0.02g of dibutyltin dilaurate. Under an argon atmosphere, heat at 75℃ for 2h to obtain a prepolymer. Add 0.47g of hydroxyl-terminated polydimethylsiloxane to 11mL of dimethylacetamide, then add dropwise to 9.11g of the prepolymer. Heat at 60℃ for 4h. After the reaction is complete, dry to obtain a flame-retardant adhesive.

[0059] This embodiment discloses a method for preparing a high-strength fireproof door core material, including the following steps:

[0060] Step 1: Dry the composite thermal insulation material, then spray it with an ethanol solution containing silane coupling agent, and at the same time dry the expanded perlite. Then add 7.0 kg of pretreated composite thermal insulation material, 2.3 kg of expanded perlite and 1.0 kg of glass fiber into a mixer and mix to obtain a mixture.

[0061] Step 2: Add 3.8kg of flame-retardant adhesive to 9.2kg of mixture, stir, then pour into a mold, vibrate to remove air, cure, and cut to obtain high-strength fireproof door core material.

[0062] Example 4: This example discloses a method for preparing a composite thermal insulation material, including the following steps:

[0063] Q1: 22.3 g of 1-bromododecane and 12.11 g of dimethylaminoethanol were added to a container, followed by 65 mL of acetone. The mixture was heated and stirred at 62 °C for 6 h. After the reaction was completed, the mixture was cooled, filtered under reduced pressure, recrystallized, and dried under vacuum to obtain the product. 0.12 g of alumina particles were added to a container containing 18 mL of deionized water and stirred at room temperature for 6 h. Then, 0.35 g of the product, 11 g of urea, and 7.5 μL of 1 mol / L hydrochloric acid were added, and the mixture was stirred for another 30 min to obtain mixed solution 1.

[0064] Q2: Add 6.5 mL of methyltrimethoxysilane and 1.94 mL of dimethoxydimethylsilane to 25 mL of mixed solution 1, stir and mix for 4 h, seal, and place in an 80 °C oven. Then add ethanol to the container and continue to place it in the oven. Maintain the oven temperature at 80 °C for 48 h, and then at 60 °C for 72 h. Replace the ethanol every 8-10 h. Calcinate at 200 °C, 400 °C, and 600 °C with a heating rate of 5 °C / min to obtain the composite thermal insulation material.

[0065] This embodiment discloses a method for preparing a flame-retardant adhesive, including the following steps:

[0066] S1: At a low temperature of -20℃, 26 mL of morpholine aqueous solution with a concentration of 0.23 g / mL was slowly added to a mixture of 6.27 g of cyanuric chloride and 145 mL of acetone. The mixture was stirred at -20℃ for 2 h. Then, 36 mL of sodium carbonate aqueous solution with a concentration of 0.13 g / mL was added dropwise. The mixture was stirred at -20℃ for another 2 h. After the reaction was completed, the mixture was washed and dried to obtain intermediate 1.

[0067] S2: Add 95 mL of 80% hydrazine hydrate to 1.7 g of intermediate 1, heat and stir at 72 °C for 12 h. After the reaction is complete, cool, filter, wash and dry to obtain intermediate 2.

[0068] S3: Add 1.99g of intermediate 2 to a container containing 10mL of dimethylacetamide, then add 2.38g of dicyclohexylmethane diisocyanate and 0.02g of dibutyltin dilaurate. Under an argon atmosphere, heat at 75℃ for 2h to obtain a prepolymer. Add 0.47g of hydroxyl-terminated polydimethylsiloxane to 11mL of dimethylacetamide, then add dropwise to 9.11g of the prepolymer. Heat at 60℃ for 4h. After the reaction is complete, dry to obtain a flame-retardant adhesive.

[0069] This embodiment discloses a method for preparing a high-strength fireproof door core material, including the following steps:

[0070] Step 1: Dry the composite thermal insulation material, then spray it with an ethanol solution containing silane coupling agent, and at the same time dry the expanded perlite. Then add 5.5 kg of pretreated composite thermal insulation material, 1.8 kg of expanded perlite and 1.2 kg of glass fiber into a mixer and mix to obtain a mixture.

[0071] Step 2: Add 2.8kg of flame-retardant adhesive to 8.1kg of mixture, stir, then pour into a mold, vibrate to remove air, cure, and cut to obtain high-strength fireproof door core material.

[0072] Comparative Example 5: This embodiment discloses a method for preparing a composite thermal insulation material, including the following steps:

[0073] Q1: 28.7g of 1-bromododecane and 14.78g of dimethylaminoethanol were added to a container, followed by 75mL of acetone. The mixture was heated and stirred at 62℃ for 6h. After the reaction was completed, the mixture was cooled, filtered under reduced pressure, recrystallized, and dried under vacuum to obtain the product. 0.28g of alumina particles were added to a container containing 19mL of deionized water and stirred at room temperature for 6h. Then, 0.45g of the product, 14g of urea, and 8.5μL of 1mol / L hydrochloric acid were added, and the mixture was stirred for another 30min to obtain mixed solution 1.

[0074] Q2: Add 7.5 mL of methyltrimethoxysilane and 1.99 mL of dimethoxydimethylsilane to 28 mL of mixed solution 1, stir and mix for 4 h, seal, and place in an 80 °C oven. Then add ethanol to the container and continue to place it in the oven. Maintain the oven temperature at 80 °C for 48 h, and then at 60 °C for 72 h. Replace the ethanol every 8-10 h. Calcinate at 200 °C, 400 °C, and 600 °C with a heating rate of 5 °C / min to obtain the composite thermal insulation material.

[0075] This embodiment discloses a method for preparing a flame-retardant adhesive, including the following steps:

[0076] S1: At a low temperature of -20℃, 31 mL of morpholine aqueous solution with a concentration of 0.23 g / mL was slowly added to a mixture of 6.73 g of cyanuric chloride and 155 mL of acetone. The mixture was stirred at -20℃ for 2 h. Then, 38 mL of sodium carbonate aqueous solution with a concentration of 0.13 g / mL was added dropwise. The mixture was stirred at -20℃ for another 2 h. After the reaction was completed, the mixture was washed and dried to obtain intermediate 1.

[0077] S2: Add 105 mL of 80% hydrazine hydrate to 2.1 g of intermediate 1, heat and stir at 72 °C for 12 h. After the reaction is complete, cool, filter, wash and dry to obtain intermediate 2.

[0078] S3: Add 2.47g of intermediate 2 to a container containing 10mL of dimethylacetamide, then add 3.01g of dicyclohexylmethane diisocyanate and 0.02g of dibutyltin dilaurate. Under an argon atmosphere, heat at 75℃ for 2h to obtain a prepolymer. Add 0.47g of hydroxyl-terminated polydimethylsiloxane to 11mL of dimethylacetamide, then add dropwise to 9.11g of the prepolymer. Heat at 60℃ for 4h. After the reaction is complete, dry to obtain a flame-retardant adhesive.

[0079] This embodiment discloses a method for preparing a high-strength fireproof door core material, including the following steps:

[0080] Step 1: Dry the composite thermal insulation material, then spray it with an ethanol solution containing silane coupling agent, and at the same time dry the expanded perlite. Then add 6.5 kg of pretreated composite thermal insulation material, 2.1 kg of expanded perlite and 1.6 kg of glass fiber into a mixer and mix to obtain a mixture.

[0081] Step 2: Add 3.6kg of flame-retardant adhesive to 8.8kg of mixture, stir, then pour into a mold, vibrate to remove air, cure, and cut to obtain high-strength fireproof door core material.

[0082] Comparative Example 1: Compared with Example 2, Comparative Example 1 does not add composite heat insulation material in the process of preparing high-strength fireproof door core material, and all other conditions remain unchanged.

[0083] Comparative Example 2: Compared with Example 2, Comparative Example 2 used sodium silicate instead of flame-retardant adhesive in the process of preparing high-strength fireproof door core material, while other conditions remained unchanged.

[0084] The high-strength fireproof door core materials prepared according to Examples 1-5 and Comparative Examples 1-2 were subjected to performance tests. The combustion performance of the samples was tested according to GB 8624-2012, the fire resistance performance was tested according to GB / T 7633-2008, and the strength and thermal insulation performance were tested according to JC / T 2568-2020. The test results are shown in Table 1.

[0085] Table 1

[0086] project Combustion performance rating Fire resistance time / min Compressive strength / MPa Thermal conductivity / [W / (m·K)] Example 1 A 72 0.68 0.024 Example 2 A 69 0.66 0.031 Example 3 A 66 0.63 0.028 Example 4 A 68 0.64 0.029 Example 5 A 69 0.62 0.026 Comparative Example 1 A 54 0.54 0.12 Comparative Example 2 B1 67 0.56 0.026

[0087] As shown in Table 1, the fireproof door core materials prepared according to Examples 1-5 possess excellent flame retardant, fireproof, heat insulation, and strength properties. A comparison between Comparative Example 1 and Examples 1-5 reveals that the use of composite heat insulation materials can effectively improve the fireproof, heat insulation, and strength properties of the fireproof door core materials. A comparison between Comparative Example 2 and Examples 1-5 shows that the use of flame-retardant adhesives can effectively improve the flame retardant properties and strength of the fireproof door core materials.

[0088] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0089] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a high-strength fireproof door core material, characterized in that, Includes the following steps: Step 1: Dry the composite insulation material, then spray it with an ethanol solution containing silane coupling agent, and at the same time dry the expanded perlite. Then add the pretreated composite insulation material, expanded perlite and glass fiber into a mixer and mix to obtain a mixture. Step 2: Add the flame-retardant adhesive to the mixture, stir, then pour it into the mold, vibrate to remove air, cure, and cut to obtain high-strength fireproof door core material; The preparation method of the flame-retardant adhesive includes the following steps: S1: Under low temperature conditions, morpholine aqueous solution was slowly added to a mixture of cyanuric chloride and acetone, and the mixture was stirred at low temperature. Then, sodium carbonate aqueous solution was added dropwise, and the mixture was stirred at low temperature for a longer period of time. After the reaction was completed, the mixture was washed and dried to obtain intermediate 1. S2: Add 80% hydrazine hydrate to intermediate 1, heat and stir to react. After the reaction is complete, cool, filter, wash and dry to obtain intermediate 2. S3: Add intermediate 2 to a container containing dimethylacetamide, then add dicyclohexylmethane diisocyanate and dibutyltin dilaurate. Heat the mixture under an argon atmosphere to obtain a prepolymer. Add hydroxyl-terminated polydimethylsiloxane to the dimethylacetamide, then add it dropwise to the prepolymer. Heat the mixture to react. After the reaction is complete, dry the mixture to obtain a flame-retardant adhesive.

2. The method for preparing a high-strength fireproof door core material according to claim 1, characterized in that, In step one, the ratio of the amount of pretreated composite thermal insulation material, expanded perlite and glass fiber is (50-70) g: (15-23) g: (10-18) g; in step two, the ratio of the amount of flame retardant adhesive and mixture is (26-38) g: (78-92) g.

3. The method for preparing a high-strength fireproof door core material according to claim 1, characterized in that, The preparation method of the composite thermal insulation material includes the following steps: Q1: Add 1-bromododecane and dimethylaminoethanol to a container, then add acetone, heat and stir to react. After the reaction is complete, cool, filter under reduced pressure, recrystallize, and dry under vacuum to obtain the product; add alumina particles to a container containing deionized water, stir at room temperature, then add the product, urea and hydrochloric acid, and continue stirring to obtain mixed solution 1. Q2: Add methyltrimethoxysilane and dimethoxydimethylsilane to mixed solution 1, stir and mix, seal, put into an oven, then add ethanol to the container, continue to put in the oven, dry, calcine, and obtain composite heat insulation material.

4. The method for preparing a high-strength fireproof door core material according to claim 3, characterized in that, In Q1, the ratio of 1-bromododecane, dimethylaminoethanol, and acetone is (20-31.2) g : (11.21-15.42) g : (60-80) mL; the ratio of alumina particles, deionized water, product, urea, and hydrochloric acid is (0.08-0.32) g : (17-20) mL : (0.3-0.5) g : (10-15) g : (7-9) μL.

5. The method for preparing a high-strength fireproof door core material according to claim 3, characterized in that, In Q2, the ratio of the amounts of methyltrimethoxysilane, dimethoxydimethylsilane and mixed solution 1 is (6-8) mL: (1.91-2.03) mL: (24-29) mL.

6. The method for preparing a high-strength fireproof door core material according to claim 1, characterized in that, In S1, the ratio of the amounts of morpholine aqueous solution, cyanuric chloride, acetone and sodium carbonate aqueous solution is (25-32) mL : (6.12-6.93) g : (140-160) mL : (35-40) mL, the concentration of morpholine aqueous solution is 0.23 g / mL, and the concentration of sodium carbonate aqueous solution is 0.13 g / mL.

7. The method for preparing a high-strength fireproof door core material according to claim 1, characterized in that, In S2, the ratio of intermediate 1 to 80% hydrazine hydrate is (1.5-2.3) g: (90-110) mL.

8. The method for preparing a high-strength fireproof door core material according to claim 1, characterized in that, In S3, the molar ratio of intermediate 2 and dicyclohexylmethane diisocyanate is (0.8-1.2):(0.82-1.21), and the ratio of hydroxyl-terminated polydimethylsiloxane, dimethylacetamide and prepolymer is (0.43-0.52) g:(10-12) mL:(8.01-10.23) g.

9. A high-strength fireproof door core material is prepared by the preparation method described in any one of claims 1-8.

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