Aerogel flame-retardant heat-insulating coating and preparation method thereof

Abstract

The invention relates to the technical field of chemical coatings, and particularly discloses an aerogel flame-retardant heat-insulation coating and a preparation method thereof. The aerogel flame-retardant heat-insulation heat-preservation coating is prepared from the following raw materials in parts by weight: 25 to 40 parts of deionized water, 0.1 to 1.0 part of cellulose, 4 to 10 parts of a building additive, 15 to 30 parts of a silicate flame retardant, 20 to 35 parts of an emulsion, 0.5 to 3.0 parts of aerogel and 12 to 25 parts of hollow glass beads, the preparation method comprises the following steps: adding the cellulose into the deionized water, stirring and mixing, then adding the building additive and the silicate flame retardant, stirring and mixing, then adding the emulsion, stirring and mixing, finally adding the aerogel and the hollow glass beads, and uniformly mixing to obtain the aerogel flame-retardant heat-insulation coating. After the aerogel flame-retardant heat-insulation heat-preservation coating is applied, a protective layer formed by the silicate flame retardant used by the aerogel flame-retardant heat-insulation heat-preservation coating at a high temperature can show relatively good closing performance, so that the aerogel flame-retardant heat-insulation heat-preservation coating has excellent heat-insulation heat-preservation performance and flame-retardant performance.

Description

Technical Field

[0001] The present application relates to the technical field of chemical coatings, and more specifically, to an aerogel flame retardant heat insulating coating and a preparation method thereof. Background Art

[0002] Thermal insulation coatings can effectively suppress and shield infrared radiation heat and heat conduction through low thermal conductivity and high thermal resistance. They are widely used in building insulation such as interior walls, exterior walls, roofs, basements, and chemical equipment such as storage tanks, reactors, and pipeline insulation, energy saving, etc.

[0003] With the frequent occurrence of fire incidents, the development of flame retardant properties based on thermal insulation coatings has received increasing attention. By improving the flame retardant properties, the speed of flame spread can be slowed down, and combustion can be prevented within a certain period of time, thereby providing time for fire extinguishing. Thermal insulation coatings use functional fillers in the mixed matrix to obtain thermal insulation properties, and then introduce flame retardants on this basis to further obtain flame retardant properties. For example, the invention patent application document with patent publication number CN116254030A discloses a polymer emulsion intumescent fire retardant coating and its preparation process. The polymer emulsion intumescent fire retardant coating is composed of raw materials: polymer emulsion film former, intumescent flame retardant, non-intumescent inorganic thermal insulation filler, reinforcing fiber, deionized water, coupling agent, thickener, stabilizer, and nano rare earth oxide.

[0004] Regarding the above-mentioned related technologies, the inventors believe that the mechanism of action of coating flame retardants is to react at high temperatures to form a protective layer on the surface of the material to prevent combustion, preventing oxygen from entering the interior of the material, thereby preventing combustion; and thermal insulation fillers are often difficult to form a mixed system with flame retardants that is evenly distributed and has good compatibility, which leads to poor closure of the protective layer formed by the application of flame retardants, making it difficult to achieve the expected flame retardant effect.

[0005] Therefore, it is urgent to propose a solution to solve the above technical problems. Summary of the invention

[0006] In order to solve the problem of poor flame retardancy of existing thermal insulation coatings, the present application provides an aerogel flame retardant thermal insulation coating and a preparation method thereof.

[0007] In the first aspect, the present application provides an aerogel flame retardant heat insulating coating, which adopts the following technical solution: An aerogel flame retardant heat insulating coating is made of the following raw materials in parts by weight: 25-40 parts of deionized water; Cellulose 0.1-1.0 parts; 4-10 parts of building additives; 15-30 parts of silicate flame retardant; Emulsion 20-35 parts; Aerogel 0.5-3.0 parts; Hollow glass microspheres 12-25 parts.

[0008] By adopting the above technical solution, aerogel, as a lightweight nanoporous amorphous solid material, can play an excellent thermal insulation performance in the coating by reducing solid heat conduction, inhibiting air convection heat transfer and effectively blocking radiation heat conduction; hollow glass microspheres are closed hollow spherical particles, which contain a thin gas inside and have a low thermal conductivity, so they can provide excellent thermal insulation effect; aerogel and hollow glass microspheres are used together, so that the coating formed by the aerogel flame retardant thermal insulation coating can achieve good thermal insulation effect after application. The main component of silicate flame retardants is inorganic silicate, which can effectively prevent heat from being transferred from the flame to the protected material after application, and also prevent oxygen from diffusing to the combustion area, thereby reducing or delaying the combustion process and achieving its flame retardant effect. In the aerogel flame retardant, thermal insulation and thermal insulation coating of the present application, silicate flame retardants, aerogels and hollow glass microspheres are used in combination, and the adsorption and conduction effects brought by the nanoscale pore structure of the aerogel are utilized so that when the silicate flame retardant reacts at high temperature, the reaction product can be evenly and rapidly spread through the pore structure of the aerogel, and the hollow glass microspheres act as bearings in this process, making the reaction product more fluid and dispersible, so that the protective layer formed by the silicate flame retardant can show better closure, thereby bringing about a stronger flame retardant effect, ensuring that the final aerogel flame retardant, thermal insulation and thermal insulation coating can take into account both excellent thermal insulation and flame retardant properties, and the overall application quality is excellent.

[0009] Preferably, the raw materials of the aerogel flame retardant heat insulation coating further include 3-7 parts by weight of a functional additive, the functional additive is composed of modified emulsified paraffin and modified polyimide hollow fiber, and the weight ratio of the modified emulsified paraffin to the modified polyimide hollow fiber is 1:(1.6-2.4); Wherein, the modified emulsified paraffin is prepared by the following steps: The paraffin raw material and the graphene powder are mixed in a weight ratio of (20-30):1, heated and melted to mix evenly, and then an emulsifier and glycerin are added. Water is added during the stirring process, and the mixture is evenly mixed and then cooled to obtain a modified emulsified paraffin wax; The modified polyimide hollow fiber is prepared by the following steps: A polyimide hollow fiber raw material is placed in a reaction solution for stirring and reaction. The reaction solution is prepared by mixing β-cyclodextrin, 1,2,3,4-butanetetracarboxylic acid, sodium hypophosphite and water in a weight ratio of (0.15-0.18):(0.08-0.10):(0.03-0.04):1. After the reaction, the raw material is taken out and dried to obtain a modified polyimide hollow fiber.

[0010] By adopting the above technical scheme, in the preparation of modified emulsified paraffin, the use of graphene can reduce the crystallinity of paraffin, so that the obtained modified emulsified paraffin exhibits excellent fluidity; and when the modified emulsified paraffin is applied to the coating, it can utilize its own molecular lubrication effect. When the silicate flame retardant reacts at high temperature, through the carbonization effect of graphene, the protective layer formed by the silicate flame retardant is strengthened by the carbon layer, and the closure of the protective layer is better supplemented to ensure a more excellent flame retardant effect.

[0011] In the preparation of modified polyimide hollow fibers, by combining β-cyclodextrin, 1,2,3,4-butanetetracarboxylic acid and sodium hypophosphite, the obtained modified polyimide hollow fibers exhibit excellent hydrophilicity and dispersibility, and can be fully dispersed in the coating; and when the modified polyimide hollow fibers are applied to the coating, the conduction and dispersion of the reaction products of silicate flame retardants at high temperatures can be enhanced, thereby improving the flame retardant properties.

[0012] At the same time, when modified emulsified paraffin and modified polyimide hollow fiber are used together as functional additives, in addition to the above-mentioned effects, the carbon layer structure formed at high temperature relies on the surface of the modified polyimide hollow fiber, which not only has a reinforcing and complementary effect on the protective layer formed by the silicate flame retardant, but also can act as a skeleton support to maintain the stability and integrity of the closed protective layer structure, thereby significantly improving the performance of the flame retardant effect, thereby significantly improving the application quality of the aerogel flame retardant thermal insulation coating.

[0013] Preferably, the weight ratio of the modified emulsified paraffin to the modified polyimide hollow fiber is 1:2.

[0014] By adopting the above technical scheme, the modified emulsified paraffin and modified polyimide hollow fiber in the above weight ratio have a relatively excellent coordination effect when used, and the flame retardant performance of the aerogel flame retardant thermal insulation coating is also better improved.

[0015] Preferably, the silicate flame retardant is pretreated before use, and the pretreatment steps are as follows: The silicate flame retardant is placed in a sodium stearate solution with a mass fraction of 4-6%, and the solid-liquid ratio of the silicate flame retardant to the sodium stearate solution is 1g:(3-5mL), and the silicate flame retardant is treated at 75-85°C for 70-80min, then taken out and dried to obtain the pretreated silicate flame retardant.

[0016] By adopting the above technical scheme, after the silicate flame retardant is modified as above, sodium stearate reacts with the non-bridging hydroxyl group on the surface of silicate or is adsorbed on its surface, which can reduce the agglomeration of the silicate flame retardant and has higher dispersion stability; at the same time, the pretreated silicate flame retardant can also form a mixed system with aerogel and hollow glass microspheres that is uniformly distributed and has good compatibility, and can then exert more excellent flame retardant properties in subsequent applications, bringing a significant improvement in the flame retardant properties of aerogel flame retardant thermal insulation coatings.

[0017] Preferably, the aerogel is silica aerogel with a particle size of 20-50 nm; the particle size of the hollow glass microspheres is 30-100 μm.

[0018] By adopting the above technical scheme, the silica aerogel and hollow glass microspheres of the above specifications, when used, can not only play an excellent and stable thermal insulation role, but can also more easily cooperate with silicate flame retardants that react at high temperatures to play a corresponding role, thereby bringing about relatively excellent and stable flame retardant performance, which is conducive to obtaining aerogel flame retardant thermal insulation coatings with excellent application quality.

[0019] Preferably, the construction additive is one or a combination of film-forming additives, wetting agents, dispersants, defoamers, preservatives, bactericides, antifreeze agents and thickeners.

[0020] By adopting the above technical scheme, the above types of building additives are all suitable for the mixed system of aerogel flame retardant thermal insulation coatings and can give full play to their own functions. At the same time, they can also be selected and combined according to the needs of actual application scenarios, which can improve the diversity of the application of aerogel flame retardant thermal insulation coatings.

[0021] Preferably, the emulsion is one or a combination of several of acrylate emulsion, VAE emulsion, styrene-butadiene emulsion, polyvinyl acetate emulsion, styrene-modified acrylate emulsion, water-based fluorocarbon resin emulsion and water-based polyurethane emulsion.

[0022] By adopting the above technical scheme, according to different application environments and scenarios, a combination of one or several of the above components can be selected for use as an emulsion, and they can all be suitable for the excellent effects of the combination of silicate flame retardants, aerogels and hollow glass microspheres, thereby obtaining an aerogel flame retardant, heat insulating and thermal insulation coating with excellent and stable application quality.

[0023] In a second aspect, the present application provides a method for preparing an aerogel flame retardant heat insulating coating, using the following technical solution: A method for preparing an aerogel flame retardant heat insulating coating comprises the following steps: (1) preparing raw materials including deionized water, cellulose, building additives, silicate flame retardant, emulsion, aerogel and hollow glass microspheres according to a ratio; (2) adding the cellulose in step (1) into deionized water and stirring and mixing, then adding a building additive and a silicate flame retardant and stirring and mixing, then adding the emulsion and stirring and mixing, and finally adding aerogel and hollow glass microspheres and mixing evenly to obtain an aerogel flame retardant heat insulating coating.

[0024] By adopting the above technical scheme, the above method is simple to operate, and the raw materials are mixed and used in steps, which is conducive to quality control during the operation. It is not only suitable for large-scale industrial production, but also conducive to obtaining aerogel flame-retardant heat-insulating coatings with excellent and stable quality.

[0025] In summary, this application has the following beneficial effects: 1. The present application uses silicate flame retardants, aerogels and hollow glass microspheres to make the reaction products of silicate flame retardants at high temperature be spread evenly and quickly, so that the protective layer formed by the silicate flame retardants exhibits better closure, so that it is easier to approach the expected flame retardant effect, and finally obtain an aerogel flame retardant thermal insulation coating with excellent thermal insulation performance and flame retardant performance; 2. The present application uses a functional additive composed of modified emulsified paraffin and modified polyimide hollow fibers, which can not only strengthen and supplement the protective layer formed by the silicate flame retardant, but also act as a skeleton support to maintain the stability and integrity of the closed protective layer structure, thereby significantly improving the flame retardant properties of the aerogel flame retardant, thermal insulation and thermal insulation coating; 3. The present application pretreats the silicate flame retardant before use, thereby reducing the agglomeration of the silicate flame retardant and improving the dispersion stability of the silicate flame retardant, and enables the pretreated silicate flame retardant to form a uniformly distributed and compatible mixed system with aerogel and hollow glass microspheres, thereby enabling the aerogel flame retardant, thermal insulation and thermal insulation coating to exhibit better flame retardant properties after application. DETAILED DESCRIPTION

[0026] The present application is further described in detail below in combination with preparation examples, embodiments and comparative examples.

[0027] Unless otherwise specified, the raw materials used in the preparation examples, embodiments and comparative examples of the present application are commercially available: Cellulose was purchased from hydroxyethyl cellulose from Jinan Kaichuang Chemical Co., Ltd. The silicate flame retardant was purchased from BYK layered silicate BYK-MAX CT 4260 silicone flame retardant; Acrylate emulsion was purchased from Guangzhou Batai New Material Technology Co., Ltd., model BT-6509; The film-forming aid was purchased from Wuhan Runxingyuan Technology Co., Ltd., which is a film-forming aid alcohol ester twelve; The dispersant was purchased from BASF as Dispex AA4140; The defoamer was purchased from Evonik Tego Foamex 810; The paraffin raw material is 48# refined paraffin; Graphene powder was purchased from Qingdao Hexinda Carbon Materials Co., Ltd. Industrial-grade graphene with a particle size of 0.07 mm; Emulsifier NP-15 was purchased from Xingtai Xinlanxing Technology Co., Ltd.; The polyimide hollow fiber raw material was purchased from Jiangsu Xiannuo New Material Technology Co., Ltd., model number is S0T.

[0028] Preparation examples of raw materials and / or intermediates Preparation Example 1 A modified emulsified paraffin is prepared by the following steps: Take paraffin raw material and graphene powder in a weight ratio of 25:1, mix them, heat to 85°C to melt and mix evenly, add emulsifier and glycerol, add water during stirring at 600r / min, mix evenly for 10 minutes, then cool to room temperature 25°C to obtain modified emulsified paraffin.

[0029] Note: In the above operation, the amount of emulsifier used is 35% of the weight of the paraffin raw material, the amount of glycerol used is 5% of the weight of the paraffin raw material, and the amount of water used is 40% of the weight of the paraffin raw material.

[0030] Preparation Example 2 A modified emulsified paraffin, which is different from Preparation Example 1 in that the weight ratio of the paraffin raw material to the graphene powder is 20:1.

[0031] Preparation Example 3 A modified emulsified paraffin, which is different from Preparation Example 1 in that the weight ratio of the paraffin raw material to the graphene powder is 30:1.

[0032] Preparation Example 4 A modified polyimide hollow fiber is prepared by the following steps: The polyimide hollow fiber raw material was placed in a reaction solution and stirred at 200 r / min for 2 hours. The reaction solution was obtained by mixing β-cyclodextrin, 1,2,3,4-butanetetracarboxylic acid, sodium hypophosphite and water in a weight ratio of 0.165:0.09:0.035:1. After the reaction, the raw material was taken out and dried at 100°C for 5 minutes to obtain a modified polyimide hollow fiber.

[0033] Note: In the above operation, the weight ratio of the polyimide hollow fiber raw material to the reaction solution is 1:10.

[0034] Preparation Example 5 A modified polyimide hollow fiber is different from Preparation Example 4 in that the reaction solution is obtained by mixing β-cyclodextrin, 1,2,3,4-butanetetracarboxylic acid, sodium hypophosphite and water in a weight ratio of 0.15:0.08:0.03:1.

[0035] Preparation Example 6 A modified polyimide hollow fiber is different from Preparation Example 4 in that the reaction solution is obtained by mixing β-cyclodextrin, 1,2,3,4-butanetetracarboxylic acid, sodium hypophosphite and water in a weight ratio of 0.18:0.10:0.04:1.

[0036] Preparation Example 7 A pretreated silicate flame retardant is prepared by pretreating the silicate flame retardant through the following steps: The silicate flame retardant was placed in a sodium stearate solution with a mass fraction of 5%, and the solid-liquid ratio of the silicate flame retardant to the sodium stearate solution was 1g:4mL. After treating at 80°C for 75min, the pretreated silicate flame retardant was taken out and dried at 100°C for 5min to obtain the pretreated silicate flame retardant.

[0037] Preparation Example 8 A pretreated silicate flame retardant, which is different from Preparation Example 7 in that the silicate flame retardant is prepared by the following pretreatment steps: The silicate flame retardant was placed in a sodium stearate solution with a mass fraction of 4%, and the solid-liquid ratio of the silicate flame retardant to the sodium stearate solution was 1g:5mL. After treating at 75°C for 80min, the pretreated silicate flame retardant was taken out and dried at 100°C for 5min to obtain the pretreated silicate flame retardant.

[0038] Preparation Example 9 A pretreated silicate flame retardant, which is different from Preparation Example 7 in that the silicate flame retardant is prepared by the following pretreatment steps: The silicate flame retardant was placed in a sodium stearate solution with a mass fraction of 6%, and the solid-liquid ratio of the silicate flame retardant to the sodium stearate solution was 1g:3mL. After treating at 85°C for 70min, the pretreated silicate flame retardant was taken out and dried at 100°C for 5min to obtain the pretreated silicate flame retardant. Example

[0039] Example 1 An aerogel flame retardant heat insulating coating, the weight of raw materials used in its preparation is shown in Table 1, and it is prepared by the following steps: (1) preparing raw materials including deionized water, cellulose, building additives, silicate flame retardant, emulsion, aerogel and hollow glass microspheres according to a ratio; (2) Add the cellulose in step (1) to deionized water and stir at 300 r / min for 5 min, then add the building additive and silicate flame retardant and stir at 500 r / min for 10 min, then add the emulsion and stir at 500 r / min for 10 min, finally add the aerogel and hollow glass microspheres and stir at 1500 r / min for 30 min to obtain an aerogel flame retardant heat insulating coating.

[0040] Note: The construction additives are film-forming additives, dispersants and defoamers in a weight ratio of 4:3:1; the emulsion is acrylic emulsion; the aerogel is silica aerogel with a particle size of 35nm; the particle size of the hollow glass microspheres is 65μm.

[0041] Example 2-3 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 1 in that the weights of the raw materials used in its preparation are shown in Table 1.

[0042] Table 1 Raw materials used in the preparation of Examples 1-3 and their corresponding weights (kg / portion) raw material Example 1 Example 2 Example 3 Deionized water 32.5 25 40 Cellulose 0.55 0.1 0.0 Building additives 7 4 10 Silicate flame retardants 22.5 15 30 Lotion 27.5 20 35 Aerogel 1.75 0.5 3.0 Hollow glass microspheres 18.5 12 25 Example 4 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 1 in that the aerogel is a silicon dioxide aerogel with a particle size of 20 nm; and the particle size of the hollow glass microspheres is 30 μm.

[0043] Example 5 An aerogel flame retardant heat insulating and thermal insulation coating is different from Example 1 in that the aerogel is a silicon dioxide aerogel with a particle size of 50 nm; and the particle size of the hollow glass microspheres is 100 μm.

[0044] Example 6 An aerogel flame retardant, heat insulating and thermal insulation coating is different from Example 1 in that 5 parts by weight of a functional additive are also added to the raw materials of the aerogel flame retardant, heat insulating and thermal insulation coating, and the functional additive is composed of modified emulsified paraffin and modified polyimide hollow fiber in a weight ratio of 1:2, the modified emulsified paraffin is obtained by Preparation Example 1, and the modified polyimide hollow fiber is obtained by Preparation Example 4, and in the preparation of the aerogel flame retardant, heat insulating and thermal insulation coating, the functional additive is added and used together with the aerogel and hollow glass microspheres.

[0045] Example 7 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the weight parts of the functional additive added is 3 parts.

[0046] Example 8 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the weight parts of the functional additive added is 7 parts.

[0047] Example 9 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the functional additive consists of modified emulsified paraffin and modified polyimide hollow fiber in a weight ratio of 1:1.6.

[0048] Example 10 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the functional additive is composed of modified emulsified paraffin and modified polyimide hollow fiber in a weight ratio of 1:2.4.

[0049] Embodiment 11 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the functional auxiliary agent does not use modified emulsified paraffin.

[0050] Example 12 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the functional auxiliary agent does not use modified polyimide hollow fibers.

[0051] Example 13 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the modified emulsified paraffin is obtained from Preparation Example 2.

[0052] Embodiment 14 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the modified emulsified paraffin is obtained from Preparation Example 3.

[0053] Embodiment 15 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the modified polyimide hollow fiber is obtained from Preparation Example 5.

[0054] Example 16 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 6 in that the modified polyimide hollow fiber is obtained from Preparation Example 6.

[0055] Embodiment 17 An aerogel flame retardant, heat insulating and thermal insulation coating, which is different from Example 1 in that the silicate flame retardant is replaced by a pretreated silicate flame retardant, and the pretreated silicate flame retardant is obtained by Preparation Example 7.

[0056] Embodiment 18 An aerogel flame retardant heat insulating coating, which is different from Example 17 in that the pretreated silicate flame retardant is obtained from Preparation Example 8.

[0057] Embodiment 19 An aerogel flame retardant heat insulating coating, which is different from Example 17 in that the pretreated silicate flame retardant is obtained from Preparation Example 9.

[0058] Comparative Example Comparative Example 1 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 1 in that the aerogel is replaced by hollow glass microspheres.

[0059] Comparative Example 2 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 1 in that the mass of hollow glass microspheres is replaced by aerogel.

[0060] Comparative Example 3 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 1 in that hollow glass microspheres and aerogel are replaced with expanded perlite.

[0061] Comparative Example 4 An aerogel flame retardant heat insulating and thermal insulation coating, which is different from Example 1 in that hollow glass microspheres and aerogel are replaced with quartz powder.

[0062] Performance testing test samples: The aerogel flame retardant heat insulating and thermal insulation coatings obtained in Examples 1-19 were used as test samples 1-19, and the aerogel flame retardant heat insulating and thermal insulation coatings obtained in Comparative Examples 1-4 were used as control samples 1-4.

[0063] Test method: (1) Thermal insulation performance test: According to the requirements of GB / T10295-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Insulating Materials - Heat Flow Meter Method", the thermal conductivity of test samples 1-19 and control samples 1-4 was tested. When the thermal conductivity is ≤0.035, it means that the aerogel flame retardant thermal insulation coating has relatively excellent thermal insulation performance; (2) Combustion performance test: According to the requirements of GB / T14402-2007 "Combustion performance of building materials and products - Determination of calorific value", GB / T20284-2006 "Single combustion test of building materials or products", and GB 8624-2012 "Combustion performance classification of building materials and products", the combustion growth rate index (FIGRA) of test samples 1-19 and control samples 1-4 was measured. 0.2mJ , W / s) test; when the monomer is burning, a 12mm thick calcium silicate board is used as the backboard, and the sample coating amount is 700g / m 2 ; The smaller the combustion growth rate index, the better the flame retardant performance.

[0064] Table 2 Test results of test samples 1-19 and control samples 1-4 Combining Examples 1-3 and Comparative Examples 1-4 with Table 2, it can be seen that the use of silicate flame retardants in aerogel flame retardant thermal insulation coatings in combination with aerogel and hollow glass microspheres can take into account both excellent thermal insulation and flame retardant properties; at the same time, it is also found that if any one of aerogel and hollow glass microspheres is used alone as a thermal insulation filler, or other thermal insulation fillers such as expanded perlite and quartz powder are used, it is found that the flame retardant properties of the aerogel flame retardant thermal insulation coating will be greatly discounted, and the combustion growth rate index obtained by the test will be significantly increased, indicating that only when aerogel and hollow glass microspheres are matched, can the protective layer formed by the silicate flame retardant show more outstanding closure, and the flame retardant performance is more outstanding.

[0065] It can be seen from Example 1 and Examples 6-16 and Table 2 that by adding and using a functional additive composed of modified emulsified paraffin and modified polyimide hollow fiber, the flame retardant properties of the aerogel flame retardant thermal insulation coating can be further improved, and the combustion growth rate index obtained by the above test is also significantly reduced; at the same time, if any one of the modified emulsified paraffin and the modified polyimide hollow fiber is used alone as a functional additive, although it can bring about an improvement in flame retardant properties, the improvement effect is limited, and the sum of the improvement effects brought by the use of the two alone is far less than the excellent effect brought by the combination of the two. It can be seen that the combination of modified emulsified paraffin and modified polyimide hollow fiber can bring significant improvement effects.

[0066] It can be seen from Example 1 and Examples 17-19 and Table 2 that the present application can improve the flame retardant properties of the aerogel flame retardant thermal insulation coating only by pretreating the silicate flame retardant before use, indicating that the pretreated silicate flame retardant can also form a mixed system with aerogel and hollow glass microspheres that is uniformly distributed and has good compatibility, thereby being able to exert a better flame retardant effect.

[0067] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An aerogel flame retardant heat insulation coating, characterized in that: Made from the following raw materials in parts by weight: 25-40 parts of deionized water; Cellulose 0.1-1.0 parts; 4-10 parts of building additives; 15-30 parts of silicate flame retardant; 20-35 parts of emulsion; Aerogel 0.5-3.0 parts; Hollow glass microspheres 12-25 parts.

2. The aerogel flame retardant heat insulating coating according to claim 1, characterized in that: The raw materials of the aerogel flame retardant heat insulation coating are further added with 3-7 parts by weight of a functional additive, the functional additive is composed of modified emulsified paraffin and modified polyimide hollow fiber, and the weight ratio of the modified emulsified paraffin to the modified polyimide hollow fiber is 1: (1.6-2.4); Wherein, the modified emulsified paraffin is prepared by the following steps: Take paraffin raw material and graphene powder in a weight ratio of (20-30):1, mix them, heat and melt them until they are evenly mixed, add emulsifier and glycerin, add water during stirring, mix them evenly and then cool them to obtain modified emulsified paraffin; The modified polyimide hollow fiber is prepared by the following steps: A polyimide hollow fiber raw material is placed in a reaction solution and stirred for reaction. The reaction solution is prepared by mixing β-cyclodextrin, 1,2,3,4-butanetetracarboxylic acid, sodium hypophosphite and water in a weight ratio of (0.15-0.18): (0.08-0.10): (0.03-0.04):

1. After the reaction, the raw material is taken out and dried to obtain a modified polyimide hollow fiber.

3. The aerogel flame retardant heat insulating coating according to claim 2 is characterized in that: The weight ratio of the modified emulsified paraffin to the modified polyimide hollow fiber is 1:

2.

4. The aerogel flame retardant heat insulating coating according to claim 1, characterized in that: The silicate flame retardant is pretreated before use, and the pretreatment steps are as follows: The silicate flame retardant is placed in a sodium stearate solution with a mass fraction of 4-6%, and the solid-liquid ratio of the silicate flame retardant to the sodium stearate solution is 1g: (3-5mL). After treating at 75-85°C for 70-80min, the silicate flame retardant is taken out and dried to obtain the pretreated silicate flame retardant.

5. The aerogel flame retardant heat insulating coating according to claim 1, characterized in that: The aerogel is silicon dioxide aerogel with a particle size of 20-50 nm; the particle size of the hollow glass microsphere is 30-100 μm.

6. The aerogel flame retardant heat insulating coating according to claim 1, characterized in that: The construction additive is one or a combination of film-forming additives, wetting agents, dispersants, defoamers, preservatives, bactericides, antifreeze agents and thickeners.

7. The aerogel flame retardant heat insulating coating according to claim 1, characterized in that: The emulsion is one or a combination of several of acrylate emulsion, VAE emulsion, styrene-butadiene emulsion, polyvinyl acetate emulsion, styrene-modified acrylate emulsion, water-based fluorocarbon resin emulsion and water-based polyurethane emulsion.

8. The method for preparing the aerogel flame retardant heat insulating coating according to claim 1, characterized in that: The following steps are involved: (1) preparing raw materials including deionized water, cellulose, building additives, silicate flame retardant, emulsion, aerogel and hollow glass microspheres according to the proportions; (2) Add the cellulose in step (1) to deionized water and stir to mix, then add the building additive and silicate flame retardant and stir to mix, then add the emulsion and stir to mix, finally add the aerogel and hollow glass microspheres and mix evenly to obtain an aerogel flame retardant heat insulation coating.

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