A fireproof door filling material and its application

Abstract

The present invention discloses a fireproof door filling material and its application, which is used to solve the technical problem that the compression performance and sound insulation performance of the fireproof door filler in the prior art need to be further improved. The present invention is obtained by the following steps: mixing and stirring a modified mixed filler, polyethylene glycol, a modified phosphate ester and deionized water, adding phosphoric acid to the reaction system to adjust the pH of the system to 3-4, raising the temperature of the reaction system to 70-80 °C, carrying out a heat preservation reaction for 2-3 h, and performing post-treatment to obtain a composite filler; the present invention prepares a composite filler by optimizing the composition of the filler and modifying it, and then mixing it with phthalic anhydride polyester polyol, polyethylene glycol-1000 and hydroxy silicone oil for foaming, which not only effectively improves the compression performance and sound absorption performance of the foaming material, but also improves the flame retardant performance of the material.

Description

Technical Field

[0001] The present invention relates to the technical field of foam filler processing, and particularly relates to a fireproof door filling material and its application. Background Art

[0002] With the continuous progress of modern building technology and the increasing demand for safety by people, as an important safety facility in buildings, the performance requirements for fireproof doors are becoming increasingly strict to ensure that in case of emergencies such as fires, it can effectively prevent the spread of fire, while maintaining the stability and integrity of the structure.

[0003] In the prior art, a preparation method of a brucite-based lightweight fireproof door filler with the publication number of CN107673728A includes raw material preparation, modification of Taxus chinensis bark fiber, modification of brucite, and preparation of the filler. It modifies brucite under specific conditions and has good compatibility in the mixed materials. Due to the synergistic effect of material A and graphite oxide colloid, the obtained filler has improved mechanical properties compared with brucite, and the heat release rate is reduced. The overall material has a fine and uniform microporous structure, which not only reduces the density of the material, but also can play an internal buffering role when undergoing strong thermal expansion and contraction. The fireproof performance reaches non-combustible A1 level, the performance is stable, and at the same time, the application of brucite in the fireproof field is realized. The dry density is 240 - 280 kg / m³, which is convenient for installation and easy to promote and use.

[0004] The fireproof door filler is filled in the framework of the fireproof door. On the one hand, it increases the overall flame retardant performance of the fireproof door. Its more important role is to connect and support the two panels to prevent the panels from being damaged when subjected to external collisions. However, traditional filling materials are mostly foam materials, which are easily compressed when collided, resulting in damage to the panels due to the force. Moreover, fireproof doors are usually installed in corridors adjacent to the outside world and need to have good sound insulation performance to isolate external noise pollution. Therefore, fireproof foam boards are often used as fillers for fireproof doors, but the density of the filler is relatively large, and the sound absorption and insulation effects of the fireproof door filler need to be further improved.

[0005] In view of the technical defects in this regard, a solution is now proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a fireproof door filling material and its application, which are used to solve the technical problem that the compression performance and sound insulation performance of the fireproof door filler in the prior art need to be further improved.

[0007] The purpose of the present invention can be achieved through the following technical solutions: A fireproof door filling material, which is processed by the following steps:

[0008] S1. Mix and stir the modified mixed filler, polyethylene glycol, modified phosphate ester, and deionized water. Add phosphoric acid to the reaction system to adjust the system pH to 3 - 4. Raise the temperature of the reaction system to 70 - 80 °C, hold the reaction for 2 - 3 h, and perform post-treatment to obtain the composite filler.

[0009] S2. Mix the phthalic anhydride polyester polyol, polyethylene glycol, hydroxy silicone oil, composite filler, urea, and foaming aid evenly to obtain the pre-foaming material.

[0010] S3. Under the protection of inert gas, add diisocyanate to the pre-foaming material and stir and disperse it until bubbles are generated in the pre-foaming material to obtain the foaming material.

[0011] S4. Inject the foaming material into the mold, cure and foam it, and then age it to prepare the filling material.

[0012] Further, in step S1, the dosage ratio of the modified mixed filler, polyethylene glycol, modified phosphate ester, and deionized water is 3 g: 6 g: 1 g: 50 mL. The polyethylene glycol is PEG-400. The post-treatment includes: after the reaction is completed, lower the temperature of the reaction system to room temperature, perform suction filtration, wash the filter cake with deionized water until it is neutral, then drain it, transfer the filter cake to a drying oven at 65 - 75 °C, and vacuum dry it to constant weight to obtain the composite filler.

[0013] The synthesis reaction mechanism of the composite filler is as follows:

[0014] In the reaction, under acidic conditions, protons are provided to combine with the oxygen atom in the epoxy group, making it positively charged, so it is more vulnerable to the attack of the nucleophilic reagent hydroxyl group, opening the epoxy ring to form a relatively stable carbon ion intermediate. Subsequently, this carbon ion intermediate can further react with another hydroxyl molecule or other nucleophilic reagents to generate alcohol compounds and release water molecules, modifying the polyethylene glycol on the modified mixed filler and modified phosphate ester molecules to prepare a composite filler with polyethylene glycol-modified modified mixed filler and modified phosphate ester.

[0015] Further, in step S2, the weight ratio of the phthalic anhydride polyester polyol, polyethylene glycol, hydroxy silicone oil, composite filler, urea, and foaming aid is 55 - 65: 20 - 30: 8 - 13: 15 - 18: 5 - 7: 10 - 15. The polyethylene glycol is PEG-1000. The foaming aid is composed of monofluorodichloroethane, triethylenediamine, and dipropylene glycol in a dosage ratio of 5 g: 2 g: 7 mL.

[0016] Further, in step S3, the molar amount of the diisocyanate is half of the total molar amount of the hydroxyl groups and amino groups in the pre-expanded material, and the diisocyanate is one or more of isophorone diisocyanate, m-xylylene diisocyanate, o-xylylene diisocyanate, toluene 2,6-diisocyanate, and m-phenylene diisocyanate.

[0017] Further, in step S4, the curing operation includes: placing the foamed and cured foam in a curing box at a temperature of 80 - 90°C and a humidity of 60 - 80% for 10 - 12 h, and then transferring it to a drying oven at a temperature of 60 - 70°C and drying to constant weight to obtain the filling material.

[0018] Further, the modified mixed filler is prepared by the following steps:

[0019] A1. Mix mullite fiber, hollow glass microspheres, and expanded graphite evenly to obtain a mixed filler;

[0020] A2. Mix and stir the mixed filler, tetrahydrofuran, and KH-560, raise the temperature of the reaction system to 55 - 65°C, add a catalyst to the reaction system, keep the temperature for reaction for 90 - 120 min, and perform post-treatment to obtain the modified mixed filler.

[0021] Further, in step A1, the weight ratio of mullite fiber, hollow glass microspheres, and expanded graphite is 5:2:2; in step A2, the dosage ratio of the mixed filler, tetrahydrofuran, KH-560, and the catalyst is 4 g:20 mL:3 g:5 mL, the catalyst is composed of a 0.3 - 0.5 mol / L sodium hydroxide solution and sodium stearate in a dosage ratio of 3 mL:1 g, and the post-treatment includes: after the reaction is completed, lower the temperature of the reaction system to room temperature, perform suction filtration, wash the filter cake with purified water until neutral and then drain it, transfer the filter cake to a drying oven at a temperature of 60 - 70°C, and vacuum dry to constant weight to obtain the modified mixed filler.

[0022] Further, the preparation method of the modified phosphate ester is: under the protection of an inert gas, mix and stir diethyl (chlorocarbonyl difluoromethyl)phosphonate, 1-(oxiran-2-yl)ethane-1,2-diol, tetrahydrofuran, and potassium carbonate, raise the temperature of the reaction system to 40 - 45°C, keep the temperature for reaction for 4 - 6 h, and perform post-treatment to obtain the modified phosphate ester.

[0023] The synthesis reaction formula of the modified phosphate ester is:

[0024] ;

[0025] The synthesis reaction mechanism of the modified phosphate ester is:

[0026] During the reaction process, potassium carbonate was used as a catalyst, and a nucleophilic substitution reaction occurred between the acyl chloride group on the diethyl (chlorocarbonyl difluoromethyl)phosphonate molecule and the hydroxyl group on the 1-(oxiran-2-yl)ethane-1,2-diol molecule to form an ester bond, and a diethyl phosphate modification was formed at the positions of the two phenolic hydroxyl groups of 1-(oxiran-2-yl)ethane-1,2-diol, and a modified phosphate ester was prepared.

[0027] The mass spectrometry analysis data of the modified phosphate ester were: m / z: 532.0886(100.0%), 533.0920(17.3%),

[0028] 534.0929(2.3%), 534.0954(1.4%).

[0029] Furthermore, the dosage ratio of the diethyl (chlorocarbonyl difluoromethyl)phosphonate, 1-(oxiran-2-yl)ethane-1,2-diol and potassium carbonate was 2 mol:1 mol:1.1 mol, the dosage ratio of the diethyl (chlorocarbonyl difluoromethyl)phosphonate and tetrahydrofuran was 1 g:10 mL, and the post-treatment included: keeping the reaction system at 40-45 °C, reducing the pressure to remove low-boiling substances, lowering the temperature of the reaction system to room temperature, adding absolute ethanol to the reaction system, lowering the temperature of the reaction system to 5-10 °C, stirring and dispersing for 20-30 min, filtering by suction, transferring the filtrate to a rotary evaporator with a water bath temperature of 60-70 °C, and reducing the pressure to remove low-boiling substances to obtain the modified phosphate ester.

[0030] The present invention also proposes an application of the fire door filling material, applying the fire door filling material to the manufacture of fire doors.

[0031] The present invention has the following beneficial effects:

[0032] 1. For the fire door filling material of the present invention, the mixed filler is modified by KH-560 to modify epoxy groups on the surface of the inorganic filler, and the modified mixed filler modified with epoxy groups and the modified phosphate ester modified with epoxy groups are compounded to prepare a composite filler with polyethylene glycol-modified mixed filler and modified phosphate ester. Then, the composite filler is used to enhance the mixed material composed of phthalic anhydride polyester polyol, polyethylene glycol-1000, hydroxyl silicone oil and urea, and after foaming treatment with a foaming aid, it reacts with isocyanate to form a foam with a closed-cell structure, obtaining a foam structure with high porosity, improving the sound absorption and noise reduction performance of the filling material. Moreover, the reaction of the active functional groups on the phthalic anhydride polyester polyol, polyethylene glycol-1000, hydroxyl silicone oil and composite filler molecules with isocyanate forms a cross-linked network structure, improving the structural stability of the material and making the material have good compressive stress.

[0033] 2. The fireproof door filling material of the present invention uses a combination of mullite fiber, hollow glass microspheres, and expanded graphite as the mixed filler. With mullite fiber as the skeleton support, the hollow structure of the low-density hollow glass microspheres can absorb and disperse external forces, improving the compression toughness of the material. Expanded graphite is filled between the mullite fiber and hollow glass beads as an inorganic nano-powder, reducing the impact of the incorporation of expanded graphite on the mechanical strength of the material. After modifying the mixed filler and compounding it with polyethylene glycol, a composite filler is prepared to improve the dispersibility of the composite filler in the foaming material, making it easier for the inorganic filler to be evenly dispersed in the foaming material to form a stable support, thereby improving the compression performance of the filling material. By adding a modified phosphate ester to the composite filler, the modified phosphate ester serves as a phosphorus-based flame retardant. Mullite fiber can maintain a stable structure at high temperatures, is not easily combustible, and can absorb a large amount of heat, reducing the combustion temperature of the material. Expanded graphite will rapidly expand at high temperatures to form a dense carbon layer, isolating oxygen and preventing the spread of flames. The three cooperate with each other to improve the flame retardant performance of the filling material.

[0034] 3. The fireproof door filling material of the present invention dilutes phthalic anhydride polyester polyol with polyethylene glycol-1000 as the soft segment to reduce the viscosity of the pre-foaming material, making the reaction system easier to mix and process, thereby improving the uniformity and formability of the foam. Hydroxy silicone oil can reduce the surface tension of the system, making it easier for gas to diffuse in the system and form uniform bubbles. Moreover, the silicon-oxygen bond in hydroxy silicone oil has a relatively high bond energy, enabling the foam to still maintain good performance at high temperatures and in harsh environments. Urea is a nitrogen-containing organic compound that can react with isocyanate to generate intermediate products such as urethane formate. These intermediate products can further participate in the formation of polyurethane segments, thereby regulating the speed and process of the entire reaction, reducing the coalescence and rupture of bubbles, improving the uniformity and stability of the foam, increasing the rigidity and strength of the foam. Through curing and aging, the unreacted functional groups in the foam board material continue to react until the reaction is complete, promoting the release and balance of internal stress in the foam board, reducing the risk of deformation and cracking of the foam board, further improving the chemical stability and structural strength of the foam board. Moreover, the addition of urea increases the nitrogen content in the foam material, further increasing the flame retardant performance of the filling material. Detailed implementation manners

[0035] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. 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 belong to the scope of protection of the present invention.

[0036] The phthalic anhydride polyester polyol in this application has a density of 1.55 g / cm³, a viscosity of 2000 - 3000 mPa·s, an acid value of ≤ 3 mgKOH / g, and a hydroxyl value of 300 ± 30 mgKOH / g;

[0037] The hydroxyl silicone oil in this application has a viscosity of 15 - 30 mm 2 / s and a hydroxyl content of 6 - 9%.

[0038] Example 1:

[0039] This example provides a preparation method of a fire door filling material, including the following steps:

[0040] S1. Prepare the modified mixed filler:

[0041] Weigh by weight: 5 parts of mullite fiber, 2 parts of hollow glass microspheres, and 2 parts of expanded graphite, mix them evenly to obtain the mixed filler;

[0042] Mix 0.3 mol / L sodium hydroxide solution and sodium stearate evenly according to the dosage ratio of 3 mL:1 g to obtain the catalyst for standby;

[0043] Weigh: Add 800 g of the mixed filler, 4000 mL of tetrahydrofuran, and 600 g of KH - 560 into a three - necked flask and stir. Raise the temperature of the three - necked flask to 55 °C, add 1000 mL of the catalyst into the three - necked flask, keep the temperature for reaction for 90 min, then lower the temperature of the three - necked flask to room temperature, filter by suction. Wash the filter cake with purified water until neutral and then dry it by suction. Transfer the filter cake to a drying oven at 60 °C and vacuum - dry it to constant weight to obtain the modified mixed filler.

[0044] S2. Prepare the modified phosphate ester:

[0045] Weigh: Add 250.6 g of diethyl (chlorocarbonyl difluoromethyl) phosphonate, 52.1 g of 1 - (oxiran - 2 - yl) ethane - 1,2 - diol, 2506 mL of tetrahydrofuran, and 76.0 g of potassium carbonate into a three - necked flask protected by nitrogen and stir. Raise the temperature of the three - necked flask to 40 °C, keep the temperature for reaction for 4 h, keep the temperature of the three - necked flask at 40 °C, reduce the pressure to remove the low - boiling substances. Lower the temperature of the reaction system to room temperature, add 1500 mL of absolute ethanol into the reaction system, lower the temperature of the three - necked flask to 5 °C, stir and disperse for 20 min, filter by suction. Transfer the filtrate to a rotary evaporator with a water bath temperature of 60 °C and reduce the pressure to remove the low - boiling substances to obtain the modified phosphate ester.

[0046] S3. Prepare the composite filler:

[0047] Weigh: 600 g of modified mixed filler, 1200 g of PEG-400, 200 g of modified phosphate ester and 10000 mL of deionized water and add them to a three-necked flask for stirring. Add phosphoric acid to the three-necked flask to adjust the pH of the system to 3. Raise the temperature of the three-necked flask to 70 °C, keep the temperature for reaction for 2 h, then lower the temperature of the three-necked flask to room temperature, carry out suction filtration. Wash the filter cake with deionized water until it is neutral and then drain it. Transfer the filter cake to a drying oven at 65 °C and dry it under vacuum until it reaches a constant weight to obtain the composite filler.

[0048] S4. Prepare the foaming material:

[0049] Mix 5 g of 1-chloro-1,1-difluoroethane, 2 g of triethylenediamine and 7 mL of dipropylene glycol evenly to obtain the foaming aid for standby;

[0050] Weigh by weight: 55 parts of phthalic anhydride polyester polyol, 20 parts of polyethylene glycol-1000, 8 parts of hydroxy silicone oil, 15 parts of composite filler, 5 parts of urea, 10 parts of foaming aid and add them to a beaker for stirring and mixing evenly to obtain the pre-foaming material;

[0051] Introduce nitrogen into the beaker for protection. Calculate the amount of isophorone diisocyanate according to 1 / 2 of the total molar amount of hydroxyl and amino groups in the pre-foaming material and add it to the beaker containing the pre-foaming material, and stir and disperse until bubbles are generated in the pre-foaming material to obtain the foaming material.

[0052] S5. Prepare the filling material:

[0053] Inject the foaming material into the mold. After foaming and curing, a foam board with a density of 0.15 g / m 3 is obtained. Place the foam board in a curing box at 80 °C and a humidity of 60% for 10 h of aging, and then transfer it to a drying oven at 60 °C and dry it to a constant weight to obtain the filling material.

[0054] Example 2:

[0055] This example provides a preparation method of a fireproof door filling material, including the following steps:

[0056] S1. Prepare the modified mixed filler:

[0057] Weigh by weight: 5 parts of mullite fiber, 2 parts of hollow glass microspheres and 2 parts of expanded graphite, mix them evenly to obtain the mixed filler;

[0058] Mix 0.4 mol / L sodium hydroxide solution and sodium stearate evenly according to the dosage ratio of 3 mL:1 g to obtain the catalyst for standby;

[0059] Weigh: Add 800 g of mixed filler, 4000 mL of tetrahydrofuran, and 600 g of KH-560 into a three-necked flask and stir. Heat the temperature of the three-necked flask to 60 °C, add 1000 mL of catalyst into the three-necked flask, keep the temperature for reaction for 105 min, lower the temperature of the three-necked flask to room temperature, filter by suction. Wash the filter cake with purified water until it is neutral and then drain it. Transfer the filter cake to a drying oven at 65 °C and dry it under vacuum until it reaches a constant weight to obtain the modified mixed filler.

[0060] S2. Prepare the modified phosphate ester:

[0061] Weigh: Add 250.6 g of diethyl (chlorocarbonyl difluoromethyl)phosphonate, 52.1 g of 1-(oxiran-2-yl)ethane-1,2-diol, 2506 mL of tetrahydrofuran, and 76.0 g of potassium carbonate into a three-necked flask protected by nitrogen and stir. Heat the temperature of the three-necked flask to 43 °C, keep the temperature for reaction for 5 h, keep the temperature of the three-necked flask at 43 °C, reduce the pressure to remove the low-boiling substances. Lower the temperature of the reaction system to room temperature, add 1500 mL of absolute ethanol into the reaction system, lower the temperature of the three-necked flask to 7 °C, stir and disperse for 25 min, filter by suction. Transfer the filtrate to a rotary evaporator with a water bath temperature of 65 °C and reduce the pressure to remove the low-boiling substances to obtain the modified phosphate ester.

[0062] S3. Prepare the composite filler:

[0063] Weigh: Add 600 g of modified mixed filler, 1200 g of PEG-400, 200 g of modified phosphate ester, and 10000 mL of deionized water into a three-necked flask and stir. Add phosphoric acid into the three-necked flask to adjust the system pH = 3.5. Heat the temperature of the three-necked flask to 75 °C, keep the temperature for reaction for 2.5 h, lower the temperature of the three-necked flask to room temperature, filter by suction. Wash the filter cake with deionized water until it is neutral and then drain it. Transfer the filter cake to a drying oven at 70 °C and dry it under vacuum until it reaches a constant weight to obtain the composite filler.

[0064] S4. Prepare the foaming material:

[0065] Mix 1,1-dichloro-1-fluoroethane, triethylenediamine, and dipropylene glycol evenly according to the dosage ratio of 5 g:2 g:7 mL to obtain the foaming aid for standby;

[0066] Weigh by weight: Add 60 parts of phthalic anhydride polyester polyol, 25 parts of polyethylene glycol-1000, 10 parts of hydroxyl silicone oil, 17 parts of composite filler, 6 parts of urea, and 13 parts of foaming aid into a beaker and stir and mix evenly to obtain the pre-foaming material;

[0067] Pass nitrogen into the beaker for protection, calculate the dosage of isophthaloyl diisocyanate according to 1 / 2 of the total molar amount of hydroxyl and amino groups in the pre-foaming material, and add it into the beaker containing the pre-foaming material, stir and disperse until bubbles are generated in the pre-foaming material to obtain the foaming material.

[0068] S5. Preparation of filling material:

[0069] Inject the foaming material into the mold. After foaming and curing, a foam board with a density of 0.17 g / m 3 is obtained. Place the foam board in a curing box at a temperature of 85 °C and a humidity of 70% for 11 h of aging. Then transfer it to a drying oven at a temperature of 65 °C and dry it to a constant weight to obtain the filling material.

[0070] Example 3:

[0071] This example provides a preparation method of a fireproof door filling material, including the following steps:

[0072] S1. Preparation of modified mixed filler:

[0073] Weigh by weight: 5 parts of mullite fiber, 2 parts of hollow glass microspheres and 2 parts of expanded graphite, mix them evenly to obtain a mixed filler;

[0074] Mix 0.5 mol / L sodium hydroxide solution and sodium stearate evenly according to the dosage ratio of 3 mL:1 g to obtain a catalyst for standby;

[0075] Weigh: 800 g of mixed filler, 4000 mL of tetrahydrofuran, and 600 g of KH-560 and add them to a three-necked flask for stirring. The temperature of the three-necked flask is raised to 65 °C. Add 1000 mL of the catalyst to the three-necked flask, keep the temperature for reaction for 120 min, then lower the temperature of the three-necked flask to room temperature, carry out suction filtration, wash the filter cake with purified water until neutral and then drain it. Transfer the filter cake to a drying oven at a temperature of 70 °C and vacuum dry it to a constant weight to obtain the modified mixed filler.

[0076] S2. Preparation of modified phosphate ester:

[0077] Weigh: 250.6 g of bis(2,2,2-trifluoroethyl) (chlorocarbonyl)phosphonate, 52.1 g of 1-(oxiran-2-yl)ethane-1,2-diol, 2506 mL of tetrahydrofuran and 76.0 g of potassium carbonate and add them to a three-necked flask under nitrogen protection for stirring. The temperature of the three-necked flask is raised to 45 °C and keep the temperature for reaction for 6 h. Keep the temperature of the three-necked flask at 45 °C, reduce the pressure to remove low-boiling substances, lower the temperature of the reaction system to room temperature, add 1500 mL of absolute ethanol to the reaction system, lower the temperature of the three-necked flask to 10 °C, stir and disperse for 30 min, carry out suction filtration, and transfer the filtrate to a rotary evaporator with a water bath temperature of 70 °C to reduce the pressure to remove low-boiling substances to obtain the modified phosphate ester.

[0078] S3. Preparation of composite filler:

[0079] Weigh: Add 600 g of modified mixed filler, 1200 g of PEG-400, 200 g of modified phosphate ester and 10000 mL of deionized water into a three-necked flask and stir. Add phosphoric acid to the three-necked flask to adjust the pH of the system to 4. Raise the temperature of the three-necked flask to 80 °C, keep the temperature for 3 h, then lower the temperature of the three-necked flask to room temperature, filter by suction. Wash the filter cake with deionized water until it is neutral and then drain it by suction. Transfer the filter cake to a drying oven at 75 °C and dry it under vacuum until it reaches a constant weight to obtain the composite filler.

[0080] S4. Prepare the foaming material:

[0081] Mix 5 g of 1-chloro-1,1-difluoroethane, 2 g of triethylenediamine and 7 mL of dipropylene glycol evenly to obtain the foaming aid for standby;

[0082] Weigh by weight: Add 65 parts of phthalic anhydride polyester polyol, 30 parts of polyethylene glycol-1000, 13 parts of hydroxy silicone oil, 18 parts of composite filler, 7 parts of urea and 15 parts of foaming aid into a beaker and stir to mix evenly to obtain the pre-foaming material;

[0083] Introduce nitrogen into the beaker for protection. Calculate the amount of phthalic diisocyanate based on half of the total molar amount of hydroxyl and amino groups in the pre-foaming material, and add it to the beaker containing the pre-foaming material, and stir and disperse until bubbles are generated in the pre-foaming material to obtain the foaming material.

[0084] S5. Prepare the filling material:

[0085] Inject the foaming material into the mold. After foaming and curing, a foam board with a density of 0.18 g / m 3 is obtained. Place the foam board in a curing box at 90 °C and 80% humidity for 12 h, and then transfer it to a drying oven at 70 °C and dry it to a constant weight to obtain the filling material.

[0086] Comparative Example 1:

[0087] The difference between this comparative example and Example 3 is that expanded graphite is not added to the mixed filler in step S1.

[0088] Comparative Example 2:

[0089] The difference between this comparative example and Example 3 is that step S2 is cancelled and modified phosphate ester is not added in step S3.

[0090] Comparative Example 3:

[0091] The difference between this comparative example and Example 3 is that PEG-400 is not added in step S3.

[0092] Comparative Example 4:

[0093] The difference between this comparative example and Example 3 is that in step S4, urea was not added.

[0094] Performance test:

[0095] Refer to the standard GB 8624-2012 "Classification of the burning behavior of building materials and products" to determine the burning behavior grades of the filling materials prepared in Examples 1-3 and Comparative Examples 1-4;

[0096] Refer to the standard GB / T 8813-2020 "Rigid cellular plastics - Determination of compressive properties" to determine the compressive stress of the filling materials prepared in Examples 1-3 and Comparative Examples 1-4 when the relative deformation is 10%;

[0097] Refer to the standard GB / T 18696.2-2002 "Acoustics - Measurement of sound absorption coefficient and acoustic impedance in impedance tubes - Part 2: Transfer function method" to determine the sound absorption coefficients of the filling materials prepared in Examples 1-3 and Comparative Examples 1-4. The specific test results are shown in Table 1 below.

[0098] Table 1 - Data sheet for performance detection of specimens:

[0099] ;

[0100] Data analysis:

[0101] By comparing and analyzing the data in Table 1 above, the compressive stress of the filling material prepared by the present invention reaches 1905 kPa, the sound absorption coefficient reaches 0.84, and the burning behavior grade reaches A1 level. All performance parameters are superior to those of the comparative examples. The present invention optimizes the composition of the filler, modifies it with polyethylene glycol after mixing it with phosphate ester to prepare a composite filler, and then foams it after mixing it with phthalic anhydride polyester polyol, polyethylene glycol-1000, and hydroxy silicone oil, which not only effectively improves the compressive performance and sound absorption performance of the foaming material, but also improves the flame retardant performance of the material.

[0102] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only the specific embodiments. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments to better explain the principle and practical application of the present invention, so that those skilled in the relevant technical field can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A fire door filling material, characterized in that: The fire door filling material is obtained by processing the following steps: S1, mixing and stirring the modified mixed filler, polyethylene glycol, modified phosphate ester and deionized water, adding phosphoric acid to the reaction system, adjusting the system pH to 3-4, raising the temperature of the reaction system to 70-80°C, keeping the temperature for reaction for 2-3h, and post-treating to obtain a composite filler; S2, mixing phthalic anhydride polyester polyol, polyethylene glycol, hydroxy silicone oil, composite filler, urea, and foaming aid to obtain a pre-foamed material; S3, under the protection of inert gas, adding diisocyanate to the pre-foamed material, stirring and dispersing until the pre-foamed material is generated by bubbles, to obtain a foamed material; S4, injecting the foaming material into the mold, and curing after foaming to prepare a filling material; The preparation method of the modified phosphate ester is as follows: under the protection of an inert gas, diethyl (chlorocarbonyldifluoromethyl)phosphonate, 1-(oxirane-2-yl)ethane-1,2-diol, tetrahydrofuran and potassium carbonate are mixed and stirred, the temperature of the reaction system is increased to 40-45° C., the reaction is kept warm for 4-6 hours, and post-processed to obtain the modified phosphate ester; The modified mixed filler is processed by the following steps: A1, mixing mullite fiber, hollow glass microspheres and expanded graphite uniformly to obtain a mixed filler; A2. Mix and stir the mixed filler, tetrahydrofuran and KH-560, raise the temperature of the reaction system to 55-65°C, add a catalyst to the reaction system, keep the temperature for 90-120 minutes, and post-treat to obtain a modified mixed filler.

2. A fire door filling material according to claim 1, characterized in that: In step S1, the amount ratio of the modified mixed filler, polyethylene glycol, modified phosphate and deionized water is 3g:6g:1g:50mL, the polyethylene glycol is PEG-400, and the post-treatment includes: after the reaction is completed, the temperature of the reaction system is lowered to room temperature, filtered, the filter cake is washed with deionized water until it is neutral and then dried, the filter cake is transferred to a drying oven at a temperature of 65-75°C, and vacuum dried to constant weight to obtain a composite filler.

3. A fire door filling material according to claim 1, characterized in that: In step S2, the weight ratio of the phthalic anhydride polyester polyol, polyethylene glycol, hydroxy silicone oil, composite filler, urea and foaming aid is 55-65:20-30:8-13:15-18:5-7:10-15, the polyethylene glycol is PEG-1000, and the foaming aid is composed of monofluorodichloroethane, triethylenediamine and dipropylene glycol in a dosage ratio of 5g:2g:7mL.

4. A fire door filling material according to claim 1, characterized in that: In step S3, the molar amount of the diisocyanate is half of the total molar amount of the hydroxyl group and the amino group in the pre-foamed material, and the diisocyanate is one or more of isophorone diisocyanate, meta-phenylenediisocyanate, o-phenylenediisocyanate, toluene 2,6-diisocyanate, and meta-phenylenediisocyanate.

5. The fire door filling material according to claim 1, characterized in that: In step S4, the aging operation includes: placing the foamed and cured foam in a curing box at a temperature of 80-90°C and a humidity of 60-80% for aging for 10-12 hours, and then transferring it to a drying box at a temperature of 60-70°C and drying it to constant weight to obtain a filling material.

6. A fire door filling material according to claim 1, characterized in that: In step A1, the weight ratio of mullite fiber, hollow glass microsphere and expanded graphite is 5:2:2; in step A2, the amount ratio of the mixed filler, tetrahydrofuran, KH-560 and catalyst is 4g:20mL:3g:5mL, the catalyst is composed of 0.3-0.5mol / L sodium hydroxide solution and sodium stearate in an amount ratio of 3mL:1g, and the post-treatment includes: after the reaction is completed, the temperature of the reaction system is lowered to room temperature, filtered, the filter cake is washed with purified water until neutral and then dried, the filter cake is transferred to a drying oven at a temperature of 60-70°C, and vacuum dried to constant weight to obtain a modified mixed filler.

7. A fire door filling material according to claim 1, characterized in that: The dosage ratio of the diethyl (chlorocarbonyldifluoromethyl)phosphonate, 1-(oxirane-2-yl)ethane-1,2-diol and potassium carbonate is 2 mol:1 mol:1.1 mol, the dosage ratio of the diethyl (chlorocarbonyldifluoromethyl)phosphonate and tetrahydrofuran is 1 g:10 mL, and the post-treatment comprises: keeping the reaction system at 40-45° C., removing low-boiling substances under reduced pressure, lowering the temperature of the reaction system to room temperature, adding anhydrous ethanol to the reaction system, lowering the temperature of the reaction system to 5-10° C., stirring and dispersing for 20-30 minutes, filtering, transferring the filtrate to a rotary evaporator with a water bath temperature of 60-70° C., and removing low-boiling substances under reduced pressure to obtain a modified phosphate.

8. An application of a fire door filling material, characterized in that: The fire door filling material according to any one of claims 1 to 7 is applied to the manufacture of fire doors.