Flame-retardant early warning coating, preparation method thereof and application thereof

Abstract

The application belongs to the technical field of flame-retardant materials and composite boards, and particularly relates to a flame-retardant early warning coating and a preparation method and application thereof, and comprises the following steps: dissolving melamine Mel and adenosine triphosphate ATP in deionized water respectively; adding the prepared ATP solution drop by drop into the Mel solution, and performing reaction under reflux heating and stirring after dropwise addition is completed; after the reaction is completed, the reaction mixture is cooled to room temperature and left to obtain a precipitate product, and the precipitate product is washed, filtered, dried and ground to obtain modified ATP powder; the modified ATP powder, cellulose nanofiber powder CNF and graphene oxide powder GO are mixed and dispersed in deionized water to obtain a mixed solution, and the flame-retardant early warning coating is obtained through concentration and is applied to the surface of wood. The application has the advantages of efficient flame retardation, intelligent fire early warning, environmental friendliness, simple preparation process and the like.

Description

Technical Field

[0001] This invention belongs to the technical field of flame-retardant materials and composite panels, and particularly relates to a flame-retardant early warning coating, its preparation method, and its application. Background Technology

[0002] As an environmentally friendly and renewable natural resource, wood is widely used in construction, interior and exterior decoration, and papermaking due to its advantages such as low production cost, graded and porous structure, ease of processing, and biodegradability. However, its inherent flammability is one of the key issues that urgently need to be addressed in application development. The difficulties in solving the fire safety of wood and its products are mainly reflected in two aspects: (1) wood is flammable and the flame spreads rapidly when burning, posing a great potential fire hazard; (2) the warning time of traditional fire smoke sensors is usually greater than 100 seconds, and the sensitivity is low, resulting in a delayed warning response.

[0003] Fire-retardant early warning coatings are widely used on the surfaces of various flammable substrates such as wood and textiles as a convenient, economical, and effective method, simultaneously achieving both active early warning response and passive flame-retardant protection. Compared to traditional fire detectors that need to be installed in specific locations, intelligent fire-retardant coatings significantly increase the contact area with flames, making them of significant application value in improving early warning efficiency and wood fire safety.

[0004] Graphene oxide (GO) possesses a unique two-dimensional sheet structure, with its carbon atom planes modified by numerous oxygen-containing groups such as hydroxyl, carboxyl, and epoxy groups. This modification disrupts the conjugated structure of graphene, causing GO to exhibit an electrically insulating state at room temperature. However, GO's excellent thermal resistance response mechanism makes it a superior material for fire warning coatings. Once a fire occurs and the material surface temperature reaches the ignition temperature (220–500°C), the GO in the coating undergoes a reduction reaction to form reduced graphene oxide (RGO). The oxygen-containing functional groups (hydroxyl, carboxyl, etc.) on the surface are gradually lost, causing a rapid decrease in resistance between electrodes near the ignition point, thus establishing a conductive circuit and enabling timely fire warning. However, RGO has poor thermal stability under atmospheric conditions and can completely burn under flame attack. Therefore, fire warning coatings based on pure GO are insufficient to provide adequate fire warning time. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a flame-retardant early warning coating, its preparation method, and its application. This invention solves the technical problems of current flame-retardant early warning coating materials, such as high effective temperature, slow thermal reduction rate, short-lasting alarm signal, and the use of strong acids and strong oxidants, resulting in a high environmental impact.

[0006] The technical solution provided by this invention is as follows:

[0007] This invention provides a method for preparing a flame-retardant early warning coating, comprising the following steps:

[0008] Melamine (Mel) and adenosine triphosphate (ATP) were dissolved separately in deionized water;

[0009] The prepared ATP solution was added dropwise to the Mel solution. After the addition was complete, the reaction was carried out under reflux, heating and stirring.

[0010] After the reaction was completed, the reaction mixture was cooled to room temperature and allowed to stand to obtain a precipitate. The precipitate was then washed, filtered, dried and ground to obtain modified ATP powder.

[0011] Modified ATP powder, cellulose nanofiber (CNF) powder, and graphene oxide (GO) powder were mixed and dispersed in deionized water to obtain a mixed solution, which was then concentrated to obtain a flame-retardant warning coating.

[0012] Furthermore, the molar ratio of ATP to Mel in the reaction is 1:1 to 2.

[0013] Furthermore, the method for dissolving Mel in deionized water includes stirring at 80–100°C for 20–30 minutes.

[0014] Furthermore, the method of adding the prepared ATP solution dropwise to the Mel solution includes: controlling the ATP solution to be added dropwise within 20 to 30 minutes;

[0015] The heating and stirring are carried out at 80-100℃ for 4-6 hours.

[0016] Furthermore, the settling time is 8 to 10 hours.

[0017] Furthermore, the washing, filtering, drying, and grinding of the precipitated product includes:

[0018] The precipitate was washed and filtered multiple times with ultrapure water, and then vacuum dried at 40–50°C for 10–12 hours. The dried precipitate was then ball-milled for 4–6 hours.

[0019] Furthermore, the modified ATP powder has a mass of 2.5 to 10 wt% of GO, the CNF has a mass of 10 wt% of GO, and the modified ATP powder, CNF powder, and GO powder are dispersed in deionized water by ultrasonic treatment to obtain a mixed solution.

[0020] Furthermore, the mixed solution is concentrated to a concentration of 2-3% by evaporating the solvent.

[0021] The present invention also provides a flame-retardant warning coating, characterized in that it is prepared according to the preparation method of the flame-retardant warning coating described above.

[0022] The present invention also provides an application of the flame-retardant warning coating described above in improving the flame-retardant warning performance of wood, wherein the flame-retardant warning coating is applied to the wood by means of coating.

[0023] Beneficial effects

[0024] (1) The coating prepared by mixing the modified ATP powder of the present invention with cellulose nanofibers and graphene oxide exhibits highly efficient flame retardant behavior. Moreover, the assembly process does not use strong acids or strong oxidants, and the preparation and assembly process is green and environmentally friendly with a low environmental impact. At the same time, the data also shows that the limiting oxygen index (LOI) of pure wood is 24.3%. After coating three layers of graphene oxide / cellulose nanofiber coating, the LOI of the smart wood increases to 32.2%. When the modified ATP powder is added to the coating, the LOI of the wood is further increased to 67.4%, and it can reach the V-0 level in the vertical burning test, indicating that the coating with modified ATP powder has excellent flame retardant effect on wood.

[0025] (2) When the flame-retardant early warning coating prepared by this invention is applied to wood, tests show that when the wood is attacked by flames, it can trigger a fire alarm in 1.8 seconds, and the fire warning response time is as long as 58 minutes. This achieves an ultra-sensitive early warning response speed, which solves the limitations of the existing pure graphene oxide coating in fire early warning, such as short response time and unstable warning signal. This expands the application value and practical scope of graphene oxide-based fire early warning coatings. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating a flame-retardant early warning coating and its preparation method according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the flame-retardant warning coating applied to wood according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the fire-retardant early warning wood triggering an early warning according to an embodiment of the present invention. Detailed Implementation

[0029] This invention provides a method for preparing a flame-retardant early warning coating, comprising the following steps:

[0030] Step 1: Dissolve melamine (Mel) and adenosine triphosphate (ATP) separately in deionized water;

[0031] Step 2: Add the prepared ATP solution dropwise to the Mel solution. After the addition is complete, reflux and heat with stirring to carry out the reaction.

[0032] Step 3: After the reaction is complete, the reaction mixture is cooled to room temperature and allowed to stand to obtain a precipitate. The precipitate is then washed, filtered, dried and ground to obtain modified ATP powder.

[0033] Step 4: Mix and disperse modified ATP powder, cellulose nanofiber CNF powder and graphene oxide GO powder in deionized water to obtain a mixed solution, and then concentrate it to obtain a flame retardant warning coating.

[0034] In this embodiment, the specific steps for dissolving Mel in deionized water in step 1 are as follows: stirring at 80-100°C for 20-30 minutes.

[0035] In this embodiment, in step 2, the molar ratio of ATP to Mel is 1:1 to 2, the ATP solution is added dropwise within 20 to 30 minutes, and the heating and stirring are carried out at 80 to 100°C for 4 to 6 hours.

[0036] In this embodiment, in step 3, the settling time is 8-10 hours, the precipitated product is washed and filtered multiple times with ultrapure water, and vacuum dried at 40-50°C for 10-12 hours. The dried precipitated product is then ball-milled for 4-6 hours.

[0037] In this embodiment, in step 4, the mass of the modified ATP powder is 2.5 to 10 wt% of the GO mass, the mass of the CNF is 10 wt% of the GO mass, and the modified ATP powder, CNF powder and GO powder are dispersed in deionized water by ultrasonic treatment to obtain a mixed solution; the mixed solution is concentrated to a concentration of 2 to 3% by evaporating the solvent.

[0038] This invention also provides a flame-retardant warning coating, which is prepared according to the above-described method for preparing flame-retardant warning coatings.

[0039] This invention also provides an application of the flame-retardant warning coating described above in improving the flame-retardant warning performance of wood, wherein the flame-retardant warning coating is applied to the wood by coating.

[0040] The following detailed description of the preparation method and application of a flame-retardant early warning coating provided by the present invention, in conjunction with embodiments (see Table 1), should not be construed as limiting the scope of protection of the present invention.

[0041] The test methods for the performance indicators involved in the following embodiments and comparative examples are as follows:

[0042] (1) Limiting oxygen index (LOI) test: Wood samples were tested using an oxygen index meter (JF-3, Nanjing Jiangning District Analytical Instrument Factory) in accordance with GB / T 2406.2-2009 "Test method for burning performance of plastics - oxygen index method".

[0043] (2) Vertical burning test (UL-94): Wood samples were tested in accordance with GB / T 2408-2008 "Determination of the flammability of plastics - Horizontal and vertical methods". V-0 and V-1 are the V-level fire resistance test levels, of which V-0 is better than V-1. NR indicates that the test was not passed.

[0044] (3) Fire warning test (FWT): The test was conducted using a self-made fire warning device in the laboratory, which mainly consists of an adjustable low-voltage power supply (20.0V), a warning light, an alcohol lamp and several wires.

[0045] Example 1

[0046] like Figure 1-3 As shown in the figure, this embodiment provides a method for preparing and applying a flame-retardant early warning coating. The specific steps are as follows:

[0047] (1) Dissolve 7.605g of adenosine triphosphate (ATP) powder in 30mL of deionized water and stir at room temperature for 30 minutes to obtain an ATP solution; dissolve 3.78g of melamine (Mel) powder in 30mL of deionized water, place the solutions in a 250mL three-necked flask, and heat to 80℃, then reflux at 500r·min. -1 A uniformly dispersed Mel solution was obtained by magnetic stirring at a stirring speed of 0.5 for 30 minutes.

[0048] (2) Using a dropping funnel, slowly and evenly add the prepared ATP solution drop by drop into a three-necked flask over 30 minutes. After the addition is complete, magnetically stir the Mel-ATP mixture at 80°C for 2 hours to allow the reaction to proceed fully.

[0049] (3) After the reaction is completed, the product is allowed to stand at room temperature for 8 hours to obtain a precipitate. The precipitate is washed multiple times with ultrapure water to remove surface impurities and filtered. The washed precipitate is collected in a glass petri dish, sealed with a sealing film with pores left on the surface of the sealing film, and placed in a vacuum dryer at 40°C for 12 hours to obtain a pure and dry modified ATP solid. The solid is ball-milled for 6 hours to obtain modified ATP powder.

[0050] (4) 0.05g of modified ATP powder, 0.2g of cellulose nanofibers (CNF) powder and 2g of graphene oxide (GO) powder were dispersed in 200mL of deionized water solvent by ultrasonic treatment to obtain a mixed solution. The concentration of the mixed solution was concentrated to 3% by evaporating the solvent to obtain a flame retardant warning coating.

[0051] (5) Apply the above flame-retardant warning coating to wood flame-retardant warning, specifically: saw the wood into 3mm×6mm×100mm wood samples, sand the surface of the wood samples, clean them with deionized water, and dry them in a convection environment at 70-80℃ for 3-4 hours; apply a coating amount of 32-40g / m². 2 The coating is evenly applied to the surface of a clean wood sample and dried in a convective environment at 60–70°C for 2–3 hours to form the first flame-retardant warning layer. The coating process is repeated three times to finally obtain a complete warning flame-retardant layer.

[0052] Example 2

[0053] like Figure 1-3 As shown in the figure, this embodiment provides a method for preparing and applying a flame-retardant early warning coating. The specific steps are as follows:

[0054] (1) Dissolve 7.605g of ATP powder in 30mL of deionized water and stir at room temperature for 30 minutes to obtain an ATP solution; dissolve 3.78g of Mel powder in 30mL of deionized water, and place the solution in a 250mL three-necked flask. Heat the solution to 80℃ and maintain the temperature at 500r·min. -1 A uniformly dispersed Mel solution was obtained by magnetic stirring at a stirring speed of 0.5 for 30 minutes.

[0055] (2) Using a dropping funnel, slowly and evenly add the prepared ATP solution drop by drop into a three-necked flask over 30 minutes. After the addition is complete, magnetically stir the Mel-ATP mixture at 80°C for 2 hours to allow the reaction to proceed fully.

[0056] (3) After the reaction is completed, the product is allowed to stand at room temperature for 8 hours to obtain a precipitate. The precipitate is washed multiple times with ultrapure water to remove surface impurities and filtered. The washed precipitate is collected in a glass petri dish, sealed with a sealing film with pores left on the surface of the sealing film, and placed in a vacuum dryer at 40°C for 12 hours to obtain a pure and dry modified ATP solid. The solid is ball-milled for 6 hours to obtain modified ATP powder.

[0057] (4) Disperse 0.1g of modified ATP powder, 0.2g of CNF powder and 2g of GO powder in 200mL of deionized water solvent by ultrasonic treatment to obtain a mixed solution. Concentrate the mixed solution to 3% by evaporating the solvent to obtain a flame retardant warning coating.

[0058] (5) Apply the above flame-retardant warning coating to wood flame-retardant warning, specifically: saw the wood into 3mm×6mm×100mm wood samples, sand the surface of the wood samples, clean them with deionized water, and dry them in a convection environment at 70-80℃ for 3-4 hours; apply a coating amount of 32-40g / m². 2 The coating is evenly applied to the surface of a clean wood sample and dried in a convective environment at 60–70°C for 2–3 hours to form the first flame-retardant warning layer. The coating process is repeated three times to finally obtain a complete warning flame-retardant layer.

[0059] Example 3

[0060] like Figure 1-3 As shown in the figure, this embodiment provides a method for preparing and applying a flame-retardant early warning coating. The specific steps are as follows:

[0061] (1) Dissolve 7.605g of ATP powder in 30mL of deionized water and stir at room temperature for 30 minutes to obtain an ATP solution; dissolve 3.78g of Mel powder in 30mL of deionized water, and place the solution in a 250mL three-necked flask. Heat the solution to 80℃ and maintain the temperature at 500r·min. -1 A uniformly dispersed Mel solution was obtained by magnetic stirring at a stirring speed of 0.5 for 30 minutes.

[0062] (2) Using a dropping funnel, slowly and evenly add the prepared ATP solution drop by drop into a three-necked flask over 30 minutes. After the addition is complete, magnetically stir the Mel-ATP mixture at 80°C for 2 hours to allow the reaction to proceed fully.

[0063] (3) After the reaction is completed, the product is allowed to stand at room temperature for 8 hours to obtain a precipitate. The precipitate is washed multiple times with ultrapure water to remove surface impurities and filtered. The washed precipitate is collected in a glass petri dish, sealed with a sealing film with pores left on the surface of the sealing film, and placed in a vacuum dryer at 40°C for 12 hours to obtain a pure and dry modified ATP solid. The solid is ball-milled for 6 hours to obtain modified ATP powder.

[0064] (4) Disperse 0.15g of modified ATP powder, 0.2g of CNF powder and 2g of GO powder in 200mL of deionized water solvent by ultrasonic treatment to obtain a mixed solution. Concentrate the mixed solution to 3% by evaporating the solvent to obtain a flame retardant warning coating.

[0065] (5) Apply the above flame-retardant warning coating to wood flame-retardant warning, specifically: saw the wood into 3mm×6mm×100mm wood samples, sand the surface of the wood samples, clean them with deionized water, and dry them in a convection environment at 70-80℃ for 3-4 hours; apply a coating amount of 32-40g / m². 2 The coating is evenly applied to the surface of a clean wood sample and dried in a convective environment at 60–70°C for 2–3 hours to form the first flame-retardant warning layer. The coating process is repeated three times to finally obtain a complete warning flame-retardant layer.

[0066] Example 4

[0067] like Figure 1-3 As shown in the figure, this embodiment provides a method for preparing and applying a flame-retardant early warning coating. The specific steps are as follows:

[0068] (1) Dissolve 7.605g of ATP powder in 30mL of deionized water and stir at room temperature for 30 minutes to obtain an ATP solution; dissolve 3.78g of Mel powder in 30mL of deionized water, and place the solution in a 250mL three-necked flask. Heat the solution to 80℃ and maintain the temperature at 500r·min. -1 A uniformly dispersed Mel solution was obtained by magnetic stirring at a stirring speed of 0.5 for 30 minutes.

[0069] (2) Using a dropping funnel, slowly and evenly add the prepared ATP solution drop by drop into a three-necked flask over 30 minutes. After the addition is complete, magnetically stir the Mel-ATP mixture at 80°C for 2 hours to allow the reaction to proceed fully.

[0070] (3) After the reaction is completed, the product is allowed to stand at room temperature for 8 hours to obtain a precipitate. The precipitate is washed multiple times with ultrapure water to remove surface impurities and filtered. The washed precipitate is collected in a glass petri dish, sealed with a sealing film with pores left on the surface of the sealing film, and placed in a vacuum dryer at 40°C for 12 hours to obtain a pure and dry modified ATP solid. The solid is ball-milled for 6 hours to obtain modified ATP powder.

[0071] (4) Disperse 0.2g of modified ATP powder, 0.2g of CNF powder and 2g of GO powder in 200mL of deionized water solvent by ultrasonic treatment to obtain a mixed solution. Concentrate the mixed solution to 3% by evaporating the solvent to obtain a flame retardant warning coating.

[0072] (5) Apply the above flame-retardant warning coating to wood flame-retardant warning, specifically: saw the wood into 3mm×6mm×100mm wood samples, sand the surface of the wood samples, clean them with deionized water, and dry them in a convection environment at 70-80℃ for 3-4 hours; apply a coating amount of 32-40g / m². 2The coating is evenly applied to the surface of a clean wood sample and dried in a convective environment at 60–70°C for 2–3 hours to form the first flame-retardant warning layer. The coating process is repeated three times to finally obtain a complete warning flame-retardant layer.

[0073] Comparative Example 1

[0074] For untreated wood, specifically: saw the wood into 3mm×6mm×100mm wood samples, sand the surface of the wood samples, clean them with deionized water, and then dry them in a convection dryer at 70-80℃ for 3-4 hours.

[0075] Comparative Example 2

[0076] (1) 0.2g CNF powder and 2g GO powder were dispersed in 200mL deionized water solvent by ultrasonic treatment to obtain a mixed solution. The concentration of the mixed solution was concentrated to 3% by evaporation of the solvent to obtain a flame retardant warning coating.

[0077] (2) Apply the above flame-retardant warning coating to wood flame-retardant warning, specifically: saw the wood into 3mm×6mm×100mm wood samples, sand the surface of the wood samples, clean them with deionized water, and dry them in a convection dryer at 70-80℃ for 3-4 hours; apply a coating amount of 32-40g / m². 2 The coating is evenly applied to the surface of a clean wood sample and dried in a convective environment at 60–70°C for 2–3 hours to form the first flame-retardant warning layer. The coating process is repeated three times to finally obtain a complete warning flame-retardant layer.

[0078] To evaluate the fire warning function of flame-retardant early warning coatings applied to wood, this invention designs a fire warning device, such as... Figure 3 As shown, the specific operating steps are as follows: First, saw the wood into 1mm×10mm×20mm wood samples, sand the surface of the wood samples, clean them with deionized water, and then convection dry them at 60-70℃ for 0.5-1 hour; then, apply the flame-retardant warning coating at a coating amount of 32-40g / m². 2 The coating is evenly applied to the surface of a clean wood sample and dried in a convective environment at 60–70°C for 1–2 hours to form the first flame-retardant warning layer. This coating process is repeated three times to obtain the complete flame-retardant warning layer. Finally, the flame-retardant warning wood, an alarm light, and a low-voltage DC power supply (20.0V) are connected sequentially by wires to form a complete fire warning device. When an alcohol lamp flame attacks the flame-retardant warning wood, the graphene oxide in the coating undergoes a thermal reduction reaction at high temperature, forming a conductive network, thus triggering the alarm light. The response time from the flame attacking the sample to the alarm light triggering is denoted as t. a The sustained warning time of different coatings due to their varying flame-retardant properties under flame attack is denoted as t. b .

[0079] The flame retardant warning performance of the embodiments and comparative examples was tested, and the test data are shown in Table 1:

[0080] Table 1 Flame Retardant Warning Performance Test Data

[0081]

[0082] As shown in Table 1, the pure wood sample in Comparative Example 1 is easily degraded and burned when exposed to fire, failing to achieve the fire warning function. The wood sample coated with the GO / CNF coating (Comparative Example 2) triggered a fire alarm signal after approximately 7.0 seconds of exposure to flame. However, due to the poor thermal stability of the GO / CNF coating in flame, the alarm signal of Comparative Example 2 disappeared after 1.75 minutes of continuous exposure to flame. With the addition of modified ATP flame retardant in the coating formulation, the fire warning response time of Examples 1-4 showed a trend of first shortening and then lengthening. Example 3 triggered a fire warning signal only 1.8 seconds after contact with the fire source, indicating that the addition of modified ATP in the coating formulation significantly improved the sensitivity of the fire warning response of the wood sample. Furthermore, compared to Comparative Example 2, the fire warning times of Examples 1-4 were extended to 11, 21, 58, and 38 minutes, respectively, indicating that the fire resistance of the wood sample was greatly enhanced with the addition of modified ATP in the coating formulation. As shown in Table 1, based on Comparative Examples 1 and 2, the limiting oxygen index (LOI) of the wood samples after coating with the GO / CNF coating increased from 24.3% to 32.2%, and neither could pass the vertical burning (UL-94) test. With the addition of modified ATP flame retardant to the coating formulation, the LIO of the wood samples increased significantly. Based on Example 3 and Comparative Example 2, when the mass of modified ATP in the coating formulation was 7.5% of the mass of GO, the LIO of the wood samples increased from 32.2% to 54.3%, achieving the V-0 rating in the vertical burning test, demonstrating its excellent thermal stability and flame retardant properties. In summary, the embodiments of this application combine modified ATP powder with CNF and GO to form a smooth, flat, well-bonded flame-retardant warning layer of a certain thickness, enabling it to generate internal free electrons to form a conductive circuit upon contact with a fire source, thus achieving fire warning. The wood sample of this invention can trigger an early warning signal and exhibit an early warning time of up to 58 minutes after contact with a fire source of 1.8. It has reliable fire early warning and flame retardant properties such as fast fire response speed and strong fire resistance, and has important potential application value in practical fire prevention and protection.

[0083] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a flame-retardant warning coating for wood, characterized in that, Includes the following steps: Dissolve 3.78g of melamine (Mel) powder and 7.605g of adenosine triphosphate (ATP) powder separately in 30mL of deionized water; The prepared ATP solution was added dropwise to the Mel solution. After the addition was complete, the reaction was carried out under reflux, heating and stirring. After the reaction was completed, the reaction mixture was cooled to room temperature and allowed to stand to obtain a precipitate. The precipitate was then washed, filtered, dried and ground to obtain modified ATP powder. Modified ATP powder, cellulose nanofiber CNF powder and graphene oxide GO powder were mixed and dispersed in deionized water to obtain a mixed solution, which was then concentrated to obtain a flame-retardant warning coating. The modified ATP powder has a mass of 7.5 wt% of GO, and the CNF has a mass of 10 wt% of GO. The modified ATP powder, CNF powder, and GO powder are dispersed in deionized water by ultrasonic treatment to obtain a mixed solution. The mixed solution is concentrated to a concentration of 2-3% by evaporating the solvent.

2. The method for preparing the flame-retardant early warning coating for wood according to claim 1, characterized in that, The method for dissolving Mel in deionized water includes stirring at 80-100°C for 20-30 minutes.

3. The method for preparing a flame-retardant warning coating for wood according to claim 1, characterized in that, The method of adding the prepared ATP solution dropwise to the Mel solution includes: controlling the ATP solution to be added dropwise within 20-30 minutes; The heating and stirring are carried out at 80~100℃ for 4~6 hours.

4. The method for preparing a flame-retardant warning coating for wood according to claim 1, characterized in that, The settling time is 8-10 hours.

5. The method for preparing a flame-retardant early warning coating for wood according to claim 1, characterized in that, The washing, filtering, drying, and grinding of the precipitated product includes: The precipitate was washed and filtered multiple times with ultrapure water, and then vacuum dried at 40-50°C for 10-12 hours. The dried precipitate was then ball-milled for 4-6 hours.

6. A flame-retardant warning coating for wood, characterized in that, The flame-retardant warning coating for wood is prepared according to any one of claims 1 to 5.

7. The application of the flame-retardant warning coating for wood according to claim 6 in improving the flame-retardant warning performance of wood, characterized in that, The flame-retardant warning coating is applied to the wood.

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