Preparation method of flame-retardant early warning coating for building insulation materials and flame-retardant early warning coating for building insulation materials

Abstract

This application provides a method for preparing a flame-retardant early warning coating for building insulation materials and a flame-retardant early warning coating for building insulation materials. The method for preparing the flame-retardant early warning coating for building insulation materials includes the following steps: mixing graphene oxide dispersion, silicone-acrylic emulsion, ammonium polyphosphate, chitosan, and a synergist evenly; adding deionized water to prepare a mixed solution; and then adding functional additives and mixing evenly to obtain the flame-retardant early warning coating for building insulation materials; wherein the functional additives include leveling agents, wetting agents, dispersants, and defoamers. The above-mentioned flame-retardant early warning coating for building insulation materials is applied to the surface of building insulation materials to prepare a flame-retardant early warning coating for building insulation materials. Using the above preparation method to prepare the flame-retardant early warning coating and the flame-retardant early warning coating for building insulation materials can improve flame-retardant efficiency and shorten fire warning time.

Description

Technical Field

[0001] This application relates to the field of flame-retardant warning coating technology, and in particular to a method for preparing a flame-retardant warning coating for building insulation materials and a flame-retardant warning coating for building insulation materials. Background Technology

[0002] With increasingly stringent requirements for building energy conservation, applying thermal insulation materials to building exterior walls has become a standard practice in construction projects. However, fire safety hazards are becoming increasingly prominent in the actual application of building insulation materials. Most commonly used building insulation materials (such as polystyrene and polyurethane) are flammable, burn rapidly, and produce large amounts of toxic and harmful fumes during combustion. Once a fire breaks out, the flames can easily spread rapidly along the insulation material, quickly forming a large-scale fire and posing significant challenges to evacuation and firefighting.

[0003] Furthermore, existing fire warning systems in buildings primarily monitor open flames inside the building, often only issuing warnings after the fire has significantly expanded. By this time, the optimal window for fire control and suppression has been missed, potentially leading to significant casualties and property damage. Therefore, there is a need to develop a fire-retardant warning coating for building insulation materials that can improve flame-retardant efficiency and shorten fire warning time. Summary of the Invention

[0004] The purpose of this application is to provide a method for preparing a flame-retardant early warning coating for building insulation materials and a flame-retardant early warning coating for building insulation materials, which can improve flame-retardant efficiency and shorten fire warning time. The specific technical solution is as follows:

[0005] The first aspect of this application provides a method for preparing a flame-retardant early warning coating for building insulation materials, which includes the following steps:

[0006] The graphene oxide dispersion, silicone acrylic emulsion, ammonium polyphosphate, chitosan, and synergist are mixed evenly, deionized water is added to make a mixed solution, and then functional additives are added and mixed evenly to obtain a flame-retardant early warning coating for building insulation materials.

[0007] The functional additives include leveling agents, wetting agents, dispersants, and defoamers. Based on the quality of the flame-retardant early warning coating for building insulation materials, the mass percentage of graphene oxide dispersion is 0.0018% to 0.0141%, the mass percentage of silicone-acrylic emulsion is 12% to 16%, the mass percentage of ammonium polyphosphate is 30% to 34%, the mass percentage of chitosan is 8% to 12%, the mass percentage of synergist is 5% to 9%, the mass percentage of deionized water is 33% to 38%, and the mass percentage of functional additives is 1.3% to 1.5%.

[0008] In some embodiments of this application, the synergist includes at least one of titanium dioxide, zinc borate, or halloysite.

[0009] In some embodiments of this application, the graphene oxide dispersion includes a first solute and a first solvent, wherein the first solute is graphene oxide, and the first solvent includes at least one of deionized water, ethanol, N,N-dimethylformamide or N-methylpyrrolidone, and the solid content of the graphene oxide dispersion is 1 wt% to 3 wt%.

[0010] In some embodiments of this application, the silicone-acrylic emulsion includes a second solute and a second solvent, the second solute including organosilicon and polyacrylate, the second solvent including deionized water, and the solid content of the silicone-acrylic emulsion being 45wt% to 48wt%.

[0011] In some embodiments of this application, the leveling agent includes at least one of acrylate copolymers, fluorinated acrylates, or silicone-modified acrylates, and the mass percentage of the leveling agent is 0.4% to 0.6% based on the mass of the flame-retardant warning coating for building insulation materials.

[0012] In some embodiments of this application, the wetting agent includes at least one of fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether, and the mass percentage of the wetting agent is 0.4% to 0.6% based on the mass of the flame-retardant warning coating for building insulation materials.

[0013] In some embodiments of this application, the dispersant includes at least one of acrylate polymers, polyurethane polymers, or polyamide polymers, and the mass percentage of the dispersant is 0.2% to 0.4% based on the mass of the flame-retardant warning coating for building insulation materials.

[0014] In some embodiments of this application, the defoamer includes at least one of mineral oil defoamer, polyether defoamer, or polyether-modified organosilicon, and the mass percentage of the defoamer is 0.2% to 0.4% based on the mass of the flame-retardant warning coating for building insulation materials.

[0015] The second aspect of this application provides a flame-retardant warning coating for building insulation materials. The flame-retardant warning coating, prepared by the method provided in the first aspect of this application, is uniformly coated on one surface of the building insulation material. The coating amount of the flame-retardant warning coating is 150 g / m². 2 Up to 600g / m 2 Then it is dried and cured to obtain a flame-retardant early warning coating for building insulation materials.

[0016] In some embodiments of this application, the drying and curing temperature is 24°C to 26°C, and the drying and curing time is 6 to 8 days.

[0017] In some embodiments of this application, the thickness of the flame-retardant warning coating on the building insulation material is 0.9 mm to 1.1 mm.

[0018] The beneficial effects of this application are:

[0019] This application provides a method for preparing a flame-retardant early warning coating for building insulation materials and a flame-retardant early warning coating for building insulation materials. The method for preparing the flame-retardant early warning coating for building insulation materials includes the following steps: mixing graphene oxide dispersion, silicone acrylic emulsion, ammonium polyphosphate, chitosan, and a synergist evenly, adding deionized water to prepare a mixed solution, and then adding functional additives and mixing evenly to obtain the flame-retardant early warning coating for building insulation materials; wherein, the functional additives include leveling agents, wetting agents, dispersants, and defoamers; based on the mass of the flame-retardant early warning coating for building insulation materials, the mass percentage of graphene oxide dispersion is 0.0018% to 0.0141%, the mass percentage of silicone acrylic emulsion is 12% to 16%, the mass percentage of ammonium polyphosphate is 30% to 34%, the mass percentage of chitosan is 8% to 12%, the mass percentage of synergist is 5% to 9%, the mass percentage of deionized water is 33% to 38%, and the mass percentage of functional additives is 1.3% to 1.5%. A flame-retardant warning coating for building insulation materials was prepared using the above-mentioned preparation method. This flame-retardant warning coating was then applied to the surface of building insulation materials to obtain a flame-retardant warning coating layer. Specifically, a silicone-acrylic emulsion was used as the film-forming agent. Ammonium polyphosphate and chitosan were combined to form a ternary intumescent system with an acid source, a gas source, and a carbon source. A synergist played a role in catalyzing char formation, densifying and stabilizing the layer, and enhancing smoke suppression. Graphene oxide dispersion served as the warning particles. This multi-component blend of ammonium polyphosphate, chitosan, synergist, and graphene oxide dispersion formed a synergistic intumescent flame-retardant coating that, during pyrolysis, enhances the flame-retardant effect on building insulation materials. A relatively stable porous cross-linked carbon layer forms on the surface of the material, which can effectively isolate the transmission of heat and oxygen, thus exhibiting high flame retardant efficiency. At the same time, when the pyrolysis temperature of the graphene oxide in the flame retardant warning coating of the building insulation material exceeds about 110℃, the hydroxyl and carboxyl groups grafted on the graphene oxide decompose, and the material pyrolysis surface accumulates abundant C-C bonds, causing the resistance of the flame retardant warning coating of the building insulation material to drop rapidly. This allows the warning device connected to the flame retardant warning coating of the building insulation material to quickly detect the instantaneous change in resistance signal and quickly issue a fire warning, thereby shortening the fire warning time.

[0020] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these accompanying drawings.

[0022] Figure 1 The graphs show the heat release rate versus combustion time for Examples 1, 2, 3, 4, Comparative Example 1, and Comparative Example 2 of this application.

[0023] Figure 2 The graph shows the resistance changing over time during the early warning performance test of Embodiment 1 of this application.

[0024] Figure 3 The graph shows the resistance changing over time during the early warning performance test of Embodiment 2 of this application.

[0025] Figure 4 The graph shows the resistance changing over time during the early warning performance test of Embodiment 3 of this application.

[0026] Figure 5 The graph shows the resistance changing over time during the early warning performance test of Embodiment 4 of this application.

[0027] Figure 6 The graph shows the resistance change over time during the early warning performance test of Comparative Example 2 of this application. Detailed Implementation

[0028] The technical solutions of this application will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0029] The first aspect of this application provides a method for preparing a flame-retardant early warning coating for building insulation materials, which includes the following steps:

[0030] Graphene oxide dispersion (GOs), silicone acrylic emulsion, ammonium polyphosphate (APP), chitosan (CS), and synergist are mixed evenly, deionized water is added to prepare a mixed solution, and then functional additives are added and mixed evenly to obtain a flame-retardant early warning coating for building insulation materials.

[0031] The functional additives include leveling agents, wetting agents, dispersants, and defoamers. Based on the quality of the flame-retardant early warning coating for building insulation materials, the mass percentage of graphene oxide dispersion is 0.0018% to 0.0141%, the mass percentage of silicone-acrylic emulsion is 12% to 16%, the mass percentage of ammonium polyphosphate is 30% to 34%, the mass percentage of chitosan is 8% to 12%, the mass percentage of synergist is 5% to 9%, the mass percentage of deionized water is 33% to 38%, and the mass percentage of functional additives is 1.3% to 1.5%.

[0032] For example, the mass percentage of graphene oxide dispersions can be 0.0018%, 0.003%, 0.0043%, 0.0055%, 0.0067%, 0.008%, 0.0092%, 0.0104%, 0.0116%, 0.0129%, 0.0141%, or a range of any two of these values; the mass percentage of silicone-acrylic emulsions can be 12%, 12.4%, 12.8%, 13.2%, 13.6%. The mass percentages of ammonium polyphosphate can be 30%, 30.4%, 30.8%, 31.2%, 31.6%, 32%, 32.4%, 32.8%, 33.2%, 33.6%, 34%, or any two of these values; the mass percentage of chitosan can be 8%, 8.4%, 8.8%. The mass percentages of the following ingredients are: 9.2%, 9.6%, 10%, 10.4%, 10.8%, 11.2%, 11.6%, 12%, or any two of these values; the mass percentages of the synergist are: 5%, 5.4%, 5.8%, 6.2%, 6.6%, 7%, 7.4%, 7.8%, 8.2%, 8.6%, 9%, or any two of these values; the mass percentages of the deionized water are: 33%, 33.4%, 33.8%, 34.2%, 34.6%, 35%, 35.4%, 35.8%, 36.2%, 36.6%, 37%, 37.4%, 38%, or any two of these values; the mass percentages of the functional additives are: 1.3%, 1.32%, 1.34%, 1.36%, 1.38%, 1.4%, 1.42%, 1.44%, 1.46%, 1.48%, 1.5%, or any two of these values.

[0033] The inventors discovered that a flame-retardant warning coating for building insulation materials can be prepared using the above-mentioned preparation method. This flame-retardant warning coating is then applied to the surface of the building insulation material to obtain a flame-retardant warning coating layer. Specifically, a silicone-acrylic emulsion is used as the film-forming agent. Ammonium polyphosphate and chitosan are combined to form a ternary intumescent system with an acid source, a gas source, and a carbon source. A synergist plays a role in catalyzing char formation, densifying and stabilizing the layer, and enhancing smoke suppression. Graphene oxide dispersion serves as the warning particles. This multi-component blend of ammonium polyphosphate, chitosan, synergist, and graphene oxide dispersion forms a synergistic intumescent flame-retardant coating that exhibits [further properties] during pyrolysis. The surface of building insulation materials forms a relatively stable pore-like cross-linked carbon layer, which can effectively block the transmission of heat and oxygen, thus exhibiting high flame retardant efficiency. Simultaneously, when the pyrolysis temperature of graphene oxide in the flame retardant warning coating of the building insulation material exceeds approximately 110℃, the hydroxyl and carboxyl groups grafted onto the graphene oxide decompose, resulting in abundant C-C bonds accumulating on the pyrolysis surface of the material. This causes a rapid decrease in the resistance of the flame retardant warning coating, enabling the warning device connected to the coating to quickly detect the instantaneous change in resistance and rapidly issue a fire warning, thereby shortening the fire warning time.

[0034] In some embodiments, the preparation method of flame-retardant early warning coatings for building insulation materials may include the following steps:

[0035] First, the graphene oxide dispersion and silicone-acrylic emulsion are mixed under ultrasonic vibration for 25 to 35 minutes to prepare an intermediate solution. Then, the intermediate solution, ammonium polyphosphate, chitosan, synergist, and deionized water are stirred for 50 to 70 minutes to obtain a mixed solution. Functional additives are then added to the mixed solution and stirred for 50 to 70 minutes to ensure uniform mixing, thus obtaining a flame-retardant early warning coating for building insulation materials.

[0036] The functional additives include leveling agents, wetting agents, dispersants, and defoamers. Based on the quality of the flame-retardant early warning coating for building insulation materials, the mass percentage of graphene oxide dispersion is 0.0018% to 0.0141%, the mass percentage of silicone-acrylic emulsion is 12% to 16%, the mass percentage of ammonium polyphosphate is 30% to 34%, the mass percentage of chitosan is 8% to 12%, the mass percentage of synergist is 5% to 9%, the mass percentage of deionized water is 33% to 38%, and the mass percentage of functional additives is 1.3% to 1.5%.

[0037] This application does not impose any particular limitation on the stirring equipment, as long as it can achieve the purpose of this application. For example, stirring can be carried out in a grinder or a mixer. This application does not impose any particular limitation on the stirring speed, as long as it can achieve the purpose of this application. For example, the stirring speed can be from 550 rpm to 950 rpm.

[0038] In this application, after adding functional additives to the mixed solution and stirring to make it uniform, the slurry can be filtered through sieves of different mesh sizes to obtain a flame-retardant early warning coating for building insulation materials. This application has no particular limitations, as long as the purpose of this application can be achieved.

[0039] In some embodiments of this application, the synergist includes at least one of titanium dioxide (TiO2), zinc borate (ZnB), or halloysite (Hal). The selection of such synergist facilitates catalytic char formation, and the synergistic intumescent flame-retardant coating, when blended with ammonium polyphosphate, chitosan, and graphene oxide dispersion, forms a relatively stable porous cross-linked char layer on the surface of building insulation materials during pyrolysis. This effectively blocks the transfer of heat and oxygen, thereby improving flame-retardant efficiency.

[0040] In some embodiments of this application, the graphene oxide dispersion comprises a first solute and a first solvent, wherein the first solute is graphene oxide, and the first solvent comprises at least one selected from deionized water, ethanol, N,N-dimethylformamide, or N-methylpyrrolidone, and the solid content of the graphene oxide dispersion is from 1 wt% to 3 wt%. For example, the solid content of the graphene oxide dispersion may be 1 wt%, 1.2 wt%, 1.4 wt%, 1.6 wt%, 1.8 wt%, 2 wt%, 2.2 wt%, 2.4 wt%, 2.6 wt%, 2.8 wt%, 3 wt%, or a range consisting of any two of these values. The aforementioned graphene oxide dispersion is selected as the warning particle. The multi-component blend of ammonium polyphosphate, chitosan, synergist, and graphene oxide dispersion forms a relatively stable pore-like cross-linked carbon layer on the surface of building insulation materials during pyrolysis. This effectively blocks the transmission of heat and oxygen, thus exhibiting high flame retardant efficiency. Simultaneously, when the pyrolysis temperature exceeds approximately 110°C, the hydroxyl and carboxyl groups grafted onto the graphene oxide decompose, resulting in abundant C-C bonds accumulating on the pyrolysis surface of the material. This causes a rapid decrease in the resistance of the flame retardant warning coating on the building insulation material. Consequently, the warning device connected to the flame retardant warning coating can quickly detect the instantaneous change in resistance and issue a rapid fire warning, thereby shortening the fire warning time.

[0041] In some embodiments of this application, the silicone-acrylic emulsion includes a second solute and a second solvent. The second solute includes organosilicon and polyacrylate, and the second solvent includes deionized water. The solid content of the silicone-acrylic emulsion is 45 wt% to 48 wt%. For example, the solid content of the silicone-acrylic emulsion can be 45 wt%, 45.3 wt%, 45.6 wt%, 45.9 wt%, 46.2 wt%, 46.5 wt%, 46.8 wt%, 47.1 wt%, 47.4 wt%, 47.7 wt%, 48 wt%, or a range consisting of any two of these values. Using the above-mentioned silicone-acrylic emulsion as a film-forming agent is beneficial for forming a coating with a physical structure on the surface of building insulation materials.

[0042] In some embodiments of this application, the leveling agent includes at least one selected from acrylate copolymers, fluorinated acrylates, or silicone-modified acrylates. Based on the mass of the flame-retardant warning coating for building insulation materials, the mass percentage content of the leveling agent is 0.4% to 0.6%. For example, the mass percentage content of the leveling agent can be 0.4%, 0.42%, 0.44%, 0.46%, 0.48%, 0.5%, 0.52%, 0.54%, 0.56%, 0.58%, 0.6%, or a range consisting of any two of these values. Using the above-mentioned leveling agent and controlling its mass percentage within the above range is beneficial for improving the leveling performance and coating performance of the flame-retardant warning coating for building insulation materials.

[0043] In some embodiments of this application, the wetting agent includes at least one of fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether, and the mass percentage of the wetting agent is 0.4% to 0.6% based on the mass of the flame-retardant warning coating for building insulation materials. For example, the mass percentage of the wetting agent can be 0.4%, 0.42%, 0.44%, 0.46%, 0.48%, 0.5%, 0.52%, 0.54%, 0.56%, 0.58%, 0.6%, or a range consisting of any two of these values. Using the above-mentioned wetting agent and controlling its mass percentage within the above range is beneficial to improving the wetting performance and coating performance of the flame-retardant warning coating for building insulation materials.

[0044] In some embodiments of this application, the dispersant includes at least one of acrylate polymers, polyurethane polymers, or polyamide polymers. Based on the mass of the flame-retardant warning coating for building insulation materials, the mass percentage of the dispersant is 0.2% to 0.4%. For example, the mass percentage of the dispersant can be 0.2%, 0.22%, 0.24%, 0.26%, 0.28%, 0.3%, 0.32%, 0.34%, 0.36%, 0.38%, 0.4%, or a range consisting of any two of these values. The aforementioned acrylate polymer may include acrylate-methyl acrylate copolymers. Using the above-mentioned dispersant and controlling its mass percentage within the above range is beneficial for improving the dispersion performance of graphene oxide dispersion, silicone-acrylic emulsion, ammonium polyphosphate, chitosan, and synergists, thereby improving the coating performance of the flame-retardant warning coating for building insulation materials.

[0045] In some embodiments of this application, the defoamer includes at least one of mineral oil-based defoamers, polyether-based defoamers, or polyether-modified silicone. Based on the mass of the flame-retardant warning coating for building insulation materials, the mass percentage of the defoamer is 0.2% to 0.4%. For example, the mass percentage of the defoamer can be 0.2%, 0.22%, 0.24%, 0.26%, 0.28%, 0.3%, 0.32%, 0.34%, 0.36%, 0.38%, 0.4%, or a range consisting of any two of these values. Using the above-mentioned defoamer and controlling its mass percentage within the above range is beneficial to improving the coating performance of the flame-retardant warning coating for building insulation materials, thereby improving the physicochemical properties of the flame-retardant warning coating.

[0046] In some embodiments, the functional additives may also include film-forming aids. This application does not impose any particular restrictions on the type and mass percentage of film-forming aids, as long as they can achieve the purpose of this application.

[0047] The second aspect of this application provides a flame-retardant warning coating for building insulation materials. The flame-retardant warning coating, prepared by the method provided in the first aspect of this application, is uniformly coated on one surface of the building insulation material. The coating amount of the flame-retardant warning coating is 150 g / m². 2 Up to 600g / m 2 Then it is dried and cured to obtain a flame-retardant early warning coating for building insulation materials.

[0048] For example, the application rate of flame-retardant early warning coatings for building insulation materials can be 150g / m². 2 250g / m 2 350g / m 2 450g / m 2 460g / m 2 470g / m2 480g / m 2 490g / m 2 500g / m 2 510g / m 2 520g / m 2 530g / m 2 540g / m 2 550g / m 2 560g / m 2 570g / m 2 580g / m 2 590g / m 2 600g / m 2 Or it may be a range consisting of any two of these values. This application does not impose any particular limitation on building insulation materials, as long as they can achieve the purpose of this application. For example, building insulation materials may include at least one of molded polystyrene (EPS), extruded polystyrene (XPS), or polyurethane (PU).

[0049] The inventors discovered that by applying the aforementioned flame-retardant warning coating to the surface of building insulation materials, a flame-retardant warning coating for building insulation materials is prepared. In this coating, silicone-acrylic emulsion is used as the film-forming agent, and ammonium polyphosphate and chitosan are combined to form a ternary intumescent system with an acid source, a gas source, and a carbon source. A synergist plays a role in catalyzing char formation, densifying and stabilizing the layer, and enhancing smoke suppression. Graphene oxide dispersion serves as the warning particles. This multi-component blend of ammonium polyphosphate, chitosan, synergist, and graphene oxide dispersion forms a relatively stable flame-retardant coating on the surface of the building insulation material during pyrolysis. The solid, porous, cross-linked carbon layer effectively blocks the transfer of heat and oxygen, thus exhibiting high flame-retardant efficiency. Simultaneously, when the graphene oxide in the flame-retardant warning coating of the building insulation material reaches a pyrolysis temperature exceeding approximately 110°C, the hydroxyl and carboxyl groups grafted onto the graphene oxide decompose, resulting in a rich accumulation of C-C bonds on the pyrolysis surface. This causes a rapid decrease in the resistance of the flame-retardant warning coating, enabling the warning device connected to the coating to quickly detect the instantaneous resistance change and issue a rapid fire warning, thereby shortening the fire warning time.

[0050] In some embodiments of this application, the drying and curing temperature is 24°C to 26°C, and the drying and curing time is 6 to 8 days. For example, the drying and curing temperature can be 24°C, 24.3°C, 24.7°C, 25°C, 25.3°C, 25.7°C, 26°C, or a range of any two of these values; the drying and curing time can be 6 days, 7 days, 8 days, or a range of any two of these values.

[0051] This application does not impose any particular limitation on the ambient humidity for drying and curing, as long as the purpose of this application can be achieved. For example, the ambient humidity for drying and curing can be from 40%RH to 50%RH.

[0052] In some embodiments of this application, the thickness of the flame-retardant warning coating on the building insulation material is from 0.9 mm to 1.1 mm. For example, the thickness of the flame-retardant warning coating on the building insulation material can be 0.9 mm, 0.92 mm, 0.94 mm, 0.96 mm, 0.98 mm, 1 mm, 1.02 mm, 1.04 mm, 1.06 mm, 1.08 mm, 1.1 mm, or a range of any two of these values. By adjusting the thickness of the flame-retardant warning coating on the building insulation material within the above range, the flame-retardant warning coating on the building insulation material can have a high flame-retardant efficiency and can shorten the fire warning time.

[0053] Example

[0054] The embodiments and comparative examples provided below illustrate the implementation of this application in more detail. Various tests and evaluations were conducted according to the methods described below. Furthermore, unless otherwise specified, "parts" and "%" are quality standards.

[0055] Test methods and equipment:

[0056] Combustion performance test:

[0057] The sample was tested according to the international standard "Tests for reaction to fire—Heat release, smoke production and mass loss rate—Part 1: Heat release rate (cone calorimeter method)" (ISO 5660-1). The sample was a building insulation material coated with a flame-retardant warning coating. The sample size was 100mm × 100mm × 5mm. The sample surface was 25mm away from the cone heater, and the heat flux was kept constant at 50kW / m². 2 The heat release rate (HRR) and total heat release (THR) of the sample were obtained.

[0058] HRR and THR characterize the combustion performance of materials. The higher the HRR and THR values, the greater the potential fire hazard of the material, indicating poorer flame retardant properties; the lower the HRR and THR values, the lower the potential fire hazard of the material, indicating better flame retardant properties.

[0059] Early warning performance test:

[0060] Building insulation material coated with a flame-retardant warning coating was used as a sample. A 50mm × 15mm × 10mm sample was connected to a fire warning circuit consisting of a semiconductor thyristor, two power supplies, and an alarm lamp. The sample was exposed to an alcohol lamp flame to establish the correspondence between the sample and the fire warning trigger time and duration, as well as the correspondence between voltage, resistance, and temperature changes. When testing the relationship between the resistance change of the flame-retardant warning coating after contact with flame and time, the coating was continuously and repeatedly exposed to flame, and the resistance change over time under different conditions was recorded. In the fire warning performance signal output test when the building insulation material was exposed to flame, the flame was removed after each contact with the flame-retardant warning coating lasted 10 seconds; each sample was exposed to flame 5 times, and the fire signal output and the time when the resistance began to decrease were recorded.

[0061] Example 1

[0062] <Preparation of Flame-Retardant Early Warning Coatings for Building Insulation Materials>

[0063] First, mix GOs and silicone-acrylic emulsion under ultrasonic vibration for 30 minutes to prepare an intermediate solution. Then, add the intermediate solution, ammonium polyphosphate, chitosan, synergist TiO2, and deionized water to a grinder and stir for 60 minutes at 600 rpm to obtain a mixed solution. Pour the mixed solution into a beaker and add leveling agent fluorinated acrylate, wetting agent alkylphenol polyoxyethylene ether, dispersant acrylate-methyl acrylate copolymer, and defoamer polyether modified organosilicon. Place the beaker in a stirrer and stir for 60 minutes to ensure uniform mixing. Filter the slurry through a 200-mesh sieve to obtain a flame-retardant warning coating for building insulation materials.

[0064] The first solute of GOs is graphene oxide, the first solvent is deionized water, and the solid content of GOs is 2 wt%. The second solute of the silicone-acrylic emulsion includes organosilicon and polyacrylate, the second solvent is deionized water, and the solid content of the silicone-acrylic emulsion is 46 wt%. Based on the quality of the flame-retardant early warning coating for building insulation materials, the mass percentage of graphene oxide dispersion is 0.007%, the mass percentage of silicone-acrylic emulsion is 14%, the mass percentage of ammonium polyphosphate is 31.6%, the mass percentage of chitosan is 10%, the mass percentage of synergist is 7%, the mass percentage of deionized water is 35.993%, the mass percentage of leveling agent is 0.4%, the mass percentage of wetting agent is 0.4%, the mass percentage of dispersant is 0.3%, and the mass percentage of defoamer is 0.3%.

[0065] <Preparation of Flame-Retardant Early Warning Coating for Building Insulation Materials>

[0066] The flame-retardant warning coating for building insulation material prepared above is uniformly applied to one surface of the building insulation material EPS. The coating amount of the flame-retardant warning coating is 500 g / m². 2 Then, it is dried and cured at a temperature of 25°C for 7 days at an ambient humidity of 45%RH to obtain a flame-retardant warning coating for building insulation materials. The thickness of the flame-retardant warning coating for building insulation materials is 1mm.

[0067] Examples 2 to 6

[0068] Except for adjusting the relevant preparation parameters according to Table 1, everything else is the same as in Example 1.

[0069] Comparative Example 1

[0070] Except for not applying a flame-retardant warning coating to the EPS building insulation material, the rest is the same as in Example 1.

[0071] Comparative Examples 2 to 3

[0072] Except for adjusting the relevant preparation parameters according to Table 1, everything else is the same as in Example 1.

[0073] The preparation and performance parameters of each embodiment and comparative example are shown in Table 1.

[0074] Table 1

[0075] Note: In Table 1, " / " indicates that there are no relevant preparation parameters.

[0076] As can be seen from Examples 1 to 6 and Comparative Examples 1 to 3, when the flame-retardant warning coating for building insulation materials is prepared using the preparation method of this application, and the flame-retardant warning coating is applied to the surface of the building insulation material to obtain a flame-retardant warning coating, the tested peak heat release rate is low, the total heat release is low, and the time for the resistance to begin decreasing is short, indicating that the flame-retardant efficiency is effectively improved and the fire warning time is shortened. In Comparative Examples 1 to 3, Comparative Example 1 did not have a flame-retardant warning coating on the surface of the building insulation material, and the mass percentage of graphene oxide dispersion in Comparative Examples 2 and 3 was not within the range of this application. The tested peak heat release rate was high, the total heat release was high, and the time for the resistance to begin decreasing was long, indicating that the flame-retardant efficiency of Comparative Examples 1 to 3 was low and the fire warning time was long.

[0077] Depend on Figure 1It can be seen that the EPS building insulation material in Comparative Example 1 was not coated with a flame-retardant warning coating. Comparative Example 1 reached a peak heat release rate of 410 kW / m² after a combustion time of 50 seconds. 2 The flame-retardant early warning coating for building insulation materials in Comparative Example 2 does not contain graphene oxide dispersion, and the peak heat release rate of Comparative Example 2 is 320.87 kW / m². 2 In contrast, the introduction of graphene oxide dispersion as warning particles into the flame-retardant warning coatings for building insulation materials in Examples 1 to 4 resulted in a decrease in the peak heat release rate of Examples 1 to 4. Among them, the peak heat release rate of Example 1 was the lowest at 213.39 kW / m³. 2 This demonstrates that the flame retardant performance of Examples 1 to 4 was effectively improved.

[0078] Depend on Figures 2 to 6 It can be seen that the resistance began to decrease at 60s during the warning performance test of Example 1, at 150s during the warning performance test of Example 2, at 100s during the warning performance test of Example 3, at 150s during the warning performance test of Example 4, and at 180s during the warning performance test of Comparative Example 2. Among them, the resistance of Example 1 started to decrease earliest during the warning performance test compared with Examples 2 to 4 and Comparative Example 2. This may be because when the mass percentage of graphene oxide dispersion is 0.007%, the GOs particles have good dispersion performance in the flame-retardant warning coating of building insulation materials. When in contact with flame, the oxygen reduction reaction of GOs is more concentrated, and the resistance of the flame-retardant warning coating of building insulation materials decreases rapidly.

[0079] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or article that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or article.

[0080] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0081] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a flame-retardant early warning coating for building insulation materials, comprising the following steps: The graphene oxide dispersion, silicone acrylic emulsion, ammonium polyphosphate, chitosan, and synergist are mixed evenly, deionized water is added to prepare a mixed solution, and then functional additives are added and mixed evenly to obtain the flame-retardant early warning coating for building insulation materials. The functional additives include leveling agents, wetting agents, dispersants, and defoamers; based on the mass of the flame-retardant early warning coating for building insulation materials, the mass percentage of graphene oxide dispersion is 0.0018% to 0.0141%, the mass percentage of silicone-acrylic emulsion is 12% to 16%, the mass percentage of ammonium polyphosphate is 30% to 34%, the mass percentage of chitosan is 8% to 12%, the mass percentage of the synergist is 5% to 9%, the mass percentage of deionized water is 33% to 38%, and the mass percentage of the functional additives is 1.3% to 1.5%.

2. The preparation method according to claim 1, wherein, The synergist includes at least one of titanium dioxide, zinc borate, or halloysite.

3. The preparation method according to claim 1, wherein, The graphene oxide dispersion comprises a first solute and a first solvent, wherein the first solute is graphene oxide and the first solvent comprises at least one of deionized water, ethanol, N,N-dimethylformamide or N-methylpyrrolidone, and the solid content of the graphene oxide dispersion is 1 wt% to 3 wt%.

4. The preparation method according to claim 1, wherein, The silicone-acrylic emulsion includes a second solute and a second solvent. The second solute includes organosilicon and polyacrylate, and the second solvent includes deionized water. The solid content of the silicone-acrylic emulsion is 45 wt% to 48 wt%.

5. The preparation method according to claim 1, wherein, The leveling agent includes at least one of acrylate copolymers, fluorinated acrylates, or silicone-modified acrylates, and the mass percentage of the leveling agent is 0.4% to 0.6% based on the mass of the flame-retardant warning coating for the building insulation material.

6. The preparation method according to claim 1, wherein, The wetting agent includes at least one of fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether, and the mass percentage of the wetting agent is 0.4% to 0.6% based on the mass of the flame-retardant warning coating of the building insulation material.

7. The preparation method according to claim 1, wherein, The dispersant includes at least one of acrylate polymers, polyurethane polymers, or polyamide polymers, and the mass percentage of the dispersant is 0.2% to 0.4% based on the mass of the flame-retardant warning coating for the building insulation material.

8. The preparation method according to claim 1, wherein, The defoamer includes at least one of mineral oil defoamer, polyether defoamer, or polyether-modified organosilicon, and the mass percentage of the defoamer is 0.2% to 0.4% based on the mass of the flame-retardant warning coating of the building insulation material.

9. A flame-retardant warning coating for building insulation materials, wherein the flame-retardant warning coating for building insulation materials prepared by the method described in any one of claims 1 to 8 is uniformly coated on one surface of the building insulation material, and the coating amount of the flame-retardant warning coating for building insulation materials is 150 g / m². 2 Up to 600g / m 2 Then, it is dried and cured to obtain the flame-retardant early warning coating of the building insulation material.

10. The flame-retardant early warning coating for building insulation materials according to claim 9, wherein, The drying and curing temperature is 24°C to 26°C, and the drying and curing time is 6 to 8 days.

11. The flame-retardant early warning coating for building insulation materials according to claim 9, wherein, The thickness of the flame-retardant warning coating on the building insulation material is 0.9 mm to 1.1 mm.

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