Aerogel composite coating material for thermal protective textiles and preparation method and application thereof

Abstract

The present invention belongs to the field of thermal protective textiles and discloses an aerogel composite coating material for thermal protective textiles, its preparation method, and application. The raw materials for preparing the aerogel composite coating material are composed of the following components by weight: 1 to 20 parts aerogel powder, 15 to 40 parts water-based polyurethane, 15 to 40 parts water-based polyacrylate, 2 to 6 parts cross-linking agent, 8 to 15 parts flame retardant, 2 to 5 parts foaming agent, 3 to 8 parts foam stabilizer, 1 to 2 parts dispersant, and 10 to 20 parts water; the aerogel powder is obtained by doping ceramic aerogel powder with expanded graphite. The present invention introduces expanded graphite into the aerogel network of ceramic aerogel powder, which not only improves the thermal insulation and protective performance of the aerogel, but also the introduced expanded graphite can maintain the aerogel pore structure through decomposition and vaporization processes in a high-temperature environment and remove heat, thereby improving the thermal protection and thermal stability of the overall material.

Description

Technical Field

[0001] The present invention relates to the field of thermal protective textiles, and in particular to an aerogel composite coating material for thermal protective textiles, and a preparation method and application thereof. Background Art

[0002] Thermal protection is one of the basic protections in extreme working conditions, especially for practitioners of special occupations such as welding, boilers, and smelting, its protection is of great significance.

[0003] Currently, traditional thermal protection materials are primarily based on flame-retardant, insulating textiles made from fibers such as PVC or blended aramid. These textiles have limited thermal insulation performance and typically require increased weight or thicker fabrics to achieve high thermal protection. However, increasing weight and thickness can lead to operational inconvenience and operational issues. Aerogel, a porous nanostructured material, offers advantages such as high porosity, high specific surface area, high-temperature resistance, and thermal insulation and absorption, making it a high-quality thermal protection material. Traditional aerogel-based insulating textile manufacturing processes often utilize textile composite filling technology to introduce aerogel into textiles, which can impart certain thermal protection properties. However, this method only achieves the filling of aerogel powder, which is prone to deformation, pulverization, and slagging during application, making it difficult to meet the requirements for wearable thermal protection. Currently, coating technology is used to introduce aerogel into composite textile coating resins, enabling stable aerogel structures for application. However, its content is still limited, and during the carbonization process of the resin under high temperature, the internal pore structure of the aerogel easily collapses, resulting in a decrease in thermal insulation performance.

[0004] Therefore, there is an urgent need to develop a new type of flame retardant, heat insulating, and high temperature resistant aerogel coating material so that it can meet the use requirements of thermal insulation textiles and can be applied to high temperature thermal protection and other fields. Summary of the Invention

[0005] In order to address the above-mentioned deficiencies in the prior art, the present invention provides an aerogel composite coating material for thermal protective textiles, and a preparation method and application thereof.

[0006] The aerogel composite coating material for thermal protective textiles of the present invention and its preparation method and application are achieved through the following technical solutions:

[0007] The first object of the present invention is to provide an aerogel composite coating material for thermal protective textiles, the raw materials for its preparation being composed of the following components in parts by weight:

[0008] 1 to 20 parts of aerogel powder, 15 to 40 parts of waterborne polyurethane, 15 to 40 parts of waterborne polyacrylate, 2 to 6 parts of crosslinking agent, 8 to 15 parts of flame retardant, 2 to 5 parts of foaming agent, 3 to 8 parts of foam stabilizer, 1 to 2 parts of dispersant and 10 to 20 parts of water.

[0009] It should be noted that to avoid carbonization of the coating material in high-temperature operating environments, which could lead to collapse of the aerogel structure and inability to effectively provide high-temperature thermal protection, the present invention preferably uses aerogel powder obtained by doping ceramic aerogel powder with expanded graphite as one of the raw materials for preparing the coating. By introducing expanded graphite into the aerogel network of the ceramic aerogel powder, the present invention not only improves the thermal insulation and protective properties of the aerogel, but also maintains the aerogel pore structure through decomposition and vaporization processes in high-temperature environments, and removes heat, thereby improving the thermal protection and thermal stability of the overall material.

[0010] The present invention does not limit the specific type of ceramic aerogel powder, which can be selected according to actual conditions. For example, in some preferred embodiments of the present invention, the ceramic aerogel powder used can be selected from one or more of silica aerogel powder, alumina aerogel powder, and titanium oxide aerogel powder.

[0011] In order to ensure that expanded graphite can be introduced into the aerogel network of the ceramic aerogel powder and achieve the above-mentioned technical effects, in some preferred embodiments of the present invention, the aerogel powder used is prepared by the following steps:

[0012] 1) After drying the expanded graphite, grinding is performed until the flake diameter is less than 30 μm to obtain expanded graphite powder.

[0013] 2) preparing a ceramic wet gel solution corresponding to the ceramic aerogel powder.

[0014] 3) mixing the expanded graphite powder and the ceramic wet gel solution to obtain a mixture; aging the mixture at 20° C. to 60° C., and then performing a low-temperature CO2 supercritical drying process to obtain expanded graphite-doped ceramic aerogel powder.

[0015] It should be noted that, considering that small-scale expanded graphite is more easily incorporated into the aerogel network, achieving uniform doping of the expanded graphite, the present invention, in some preferred embodiments of the present invention, first grinds the expanded graphite to a flake diameter of less than 30 μm, thereby performing a primary grinding process to further reduce the expanded graphite particle size. To prevent residual moisture in the expanded graphite, which would hinder grinding, the present invention also dries the expanded graphite before grinding.

[0016] In order to ensure that the expanded graphite can be processed into expanded graphite powder with a flake diameter of less than 30 μm by grinding, in some preferred embodiments of the present invention, the expanded graphite is dried in an oven at 80° C. to 90° C. for 12 to 16 hours, then ball-milled at a speed of 6000 to 8000 r / min for 2 hours, passed through a 300-mesh sieve, and then ball-milled at a speed of 4000 to 6000 r / min for 1 to 3 hours, and passed through a 500-mesh sieve to obtain expanded graphite powder with a flake diameter of less than 30 μm.

[0017] The present invention also takes into account the factors of internal intercalation and compatibility of the aerogel network. In some more preferred embodiments of the present invention, the expanded graphite is ground to a sheet diameter of less than 10 μm to achieve expanded graphite embedded doped ceramic aerogel. And in order to ensure that the expanded graphite can be processed into expanded graphite powder with a sheet diameter of less than 10 μm by grinding, in some preferred embodiments of the present invention, the expanded graphite is dried in an oven at 80°C to 90°C for 12h to 16h, ball-milled at a speed of 6000r / min to 8000r / min for 1h to 3h using a fast grinder, passed through a 300-mesh sieve, then ball-milled at a speed of 4000r / min to 6000r / min for 1h to 3h, passed through a 500-mesh sieve, and then ball-milled at a speed of 120r / min to 300r / min using a slow fine grinder for 4h to 6h at a speed of 1500-mesh sieve, washed, and dried to obtain expanded graphite powder with a sheet diameter of less than 10 μm.

[0018] In order to distinguish and introduce the expanded graphite uniformly into the aerogel network structure, the present invention preferably adopts a mixed sol method to prepare the aerogel powder, that is, first according to the type of ceramic aerogel powder selected above, prepare the corresponding ceramic wet gel solution, then mix the ceramic wet gel solution with the expanded graphite, age and dry it to achieve the uniform introduction of the expanded graphite into the aerogel network structure, and obtain the corresponding aerogel powder.

[0019] In some preferred embodiments of the present invention, the ceramic wet gel solution is composed of the following components by weight: 80-100 parts inorganic source, 20-40 parts anhydrous ethanol, 10-20 parts deionized water, 5-10 parts dimethylformamide, 2-5 parts propylene oxide, and 2-4 parts ammonia. The inorganic source is one or more of tetraethyl orthosilicate, hydrated aluminum nitrate, and butyl titanate. Based on actual needs, the corresponding inorganic source is selected and mixed according to the above ratio to prepare the corresponding ceramic wet gel solution. For example, when it is necessary to dope expanded graphite into silica aerogel powder, in some preferred embodiments of the present invention, the ceramic wet gel solution used is composed of the following components by weight: 80-100 parts tetraethyl orthosilicate, 20-40 parts anhydrous ethanol, 10-20 parts deionized water, 5-10 parts dimethylformamide, 2-5 parts propylene oxide, and 2-4 parts ammonia. When it is necessary to dope expanded graphite into alumina aerogel powder, in some preferred embodiments of the present invention, the ceramic wet gel solution used is composed of the following components in parts by weight: 80-100 parts of hydrated aluminum nitrate, 20-40 parts of anhydrous ethanol, 10-20 parts of deionized water, 5-10 parts of dimethylformamide, 2-5 parts of propylene oxide, and 2-4 parts of aqueous ammonia. When it is necessary to dope expanded graphite into titanium oxide aerogel powder, in some preferred embodiments of the present invention, the ceramic wet gel solution used is composed of the following components in parts by weight: 80-100 parts of butyl titanate, 20-40 parts of anhydrous ethanol, 10-20 parts of deionized water, 5-10 parts of dimethylformamide, 2-5 parts of propylene oxide, and 2-4 parts of aqueous ammonia.

[0020] In order to ensure that the ceramic wet gel solution can achieve uniform dispersion of the expanded graphite powder, in some preferred embodiments of the present invention, the usage ratio of the expanded graphite powder to the ceramic wet gel solution is 1 g:100 mL to 1000 mL.

[0021] To ensure thorough mixing of the expanded graphite powder and the ceramic wet gel solution, some preferred embodiments of the present invention utilize ultrasonic mixing to achieve thorough doping and uniform dispersion of the graphite within the gel system. Furthermore, to ensure this effect, in other preferred embodiments, the ultrasonic power is 20W to 50W, the frequency is 20kHz to 50kHz, and the ultrasonic duration is 1h to 3h.

[0022] Taking into account the stability of the gel framework system, the present invention first ages the mixture of expanded graphite powder and ceramic wet gel solution to achieve a relatively stable wet gel state and reduce unstable solvent volatilization that could cause damage to the aerogel structure. The mixture is then dried at low temperature using CO2 supercritical drying to achieve the desired aerogel structure.

[0023] In order to ensure that the above effects can be achieved through aging treatment, in some preferred embodiments of the present invention, the temperature of the aging treatment is 20° C. to 60° C., and the time is 6 h to 36 h.

[0024] In order to ensure that the above-mentioned effects can be achieved through low-temperature CO2 supercritical drying, in some preferred embodiments of the present invention, the process parameters of the low-temperature CO2 supercritical drying are:

[0025] The temperature of the gel static cooler is -3°C to 3°C; the drying control conditions are: drying temperature is 30°C to 55°C, pressure is 8MPa to 15MPa, and time is 6h to 24h.

[0026] A second object of the present invention is to provide a method for preparing the above-mentioned aerogel composite coating material, comprising the following steps:

[0027] Step 1: According to the ratio of the aerogel composite coating material of the present invention, weigh the corresponding masses of various preparation raw materials and set them aside.

[0028] Step 2: After mixing the weighed aerogel powder, waterborne polyurethane, waterborne polyacrylate, crosslinking agent, flame retardant, foaming agent, foam stabilizer, dispersant and water, stir at room temperature until foaming occurs to obtain a slurry-like aerogel composite coating material.

[0029] It should be noted that in order to ensure that the various raw materials can be fully mixed, in some preferred embodiments of the present invention, a stirring pump is used for stirring, and the stirring temperature is room temperature, the stirring speed is 2500r / min~3500r / min, and the stirring time is 0.5h~1.5h, so that the various raw materials are fully foamed to obtain a uniform and stable aerogel coating slurry solution, that is, an aerogel composite coating material.

[0030] The present invention takes into account the factors of system adaptation. In some preferred embodiments of the present invention, the water-based polyurethane used is the water-based polyurethane resin AH-1720A produced by Anhui Dawei Huatai New Material Technology Co., Ltd.

[0031] The present invention takes into account the factors of system adaptation. In some preferred embodiments of the present invention, the water-based polyacrylate used is Bayhydrol A2770 produced by Guangzhou Haoyi New Materials Technology Co., Ltd.

[0032] In some preferred embodiments of the present invention, the cross-linking agent used is one or more of polyisocyanates, aziridines, and polycarbodiimides.

[0033] The present invention takes into account the factors of system adaptation. In some preferred embodiments of the present invention, the flame retardant used is one or more of phosphates, cyanates, and silicates. Among them, the phosphate ester is specifically DTFR-6007 water-based phosphate ester halogen-free liquid flame retardant produced by Suzhou Dongtuo Chemical Co., Ltd.

[0034] The present invention takes into account the factors of system adaptation. In some preferred embodiments of the present invention, the foaming agent used is L580 produced by Changzhou Zhuolian Zhichuang Polymer Materials Co., Ltd.

[0035] The present invention takes into account the factors of system adaptation. In some preferred embodiments of the present invention, the foam stabilizer used is SKD-550 produced by Tongxiang Haotian Chemical Co., Ltd.

[0036] The present invention takes into account the factors of system adaptation. In some preferred embodiments of the present invention, the dispersant used is 5040 dispersant from Guangzhou Runhong Chemical Co., Ltd.

[0037] The third object of the present invention is to provide an application of the above-mentioned aerogel composite coating material in the preparation of thermal protective textiles.

[0038] In order to ensure that the aerogel composite coating material of the present invention can be used to prepare thermal protective textiles, the present invention further provides a flame retardant and thermal insulating aerogel coated textile based on the aerogel composite coating material of the present invention, which is prepared by the following steps:

[0039] S1. According to the ratio of each raw material for preparing the aerogel composite coating material of the present invention, weigh corresponding masses of each raw material for preparation and set aside.

[0040] S2, mixing the weighed aerogel powder, water-based polyurethane, water-based polyacrylate, crosslinking agent, flame retardant, foaming agent, foam stabilizer, dispersant and water, and stirring at room temperature until foaming to obtain a slurry-like aerogel composite coating material.

[0041] S3, using a scraper coating method, scraping the slurry aerogel composite coating material onto the surface of the underlying base fabric, and then curing it at 100°C to 160°C to allow the slurry aerogel composite coating material to solidify on the surface of the underlying base fabric and form a layer of aerogel composite coating, thereby obtaining the flame retardant and heat-insulating aerogel coated textile.

[0042] It should be noted that the above S1 and S2 are actually the preparation steps of the aerogel composite coating material of the present invention, so the issues that need to be paid attention to are the same as those emphasized in the preparation method of the aerogel composite coating material, and will not be repeated here.

[0043] When the slurry aerogel composite coating material is scraped onto the surface of the underlying base fabric, in order to ensure the uniformity of the coating and at the same time ensure that the coated aerogel composite coating material can achieve the modification treatment of the underlying base fabric so that it can achieve the flame retardant and heat insulation effect, in some preferred embodiments of the present invention, the scraping amount of the slurry aerogel composite coating material is 5g / m 2 ~100g / m 2 .

[0044] In order to ensure that the slurry-like aerogel composite coating material can be cured on the surface of the underlying base fabric through the curing treatment and form a layer of aerogel composite coating, in some preferred embodiments of the present invention, the curing treatment temperature is 100°C to 160°C, and the curing treatment is 10min to 25min.

[0045] The present invention does not limit the specific type of the bottom base fabric. The corresponding bottom base fabric can be selected according to actual needs, as long as the bottom base fabric has a certain flame retardant function. For example, in some preferred embodiments of the present invention, the bottom base fabric used can be selected from fiber fabric materials that have been flame retardant modified or have intrinsic flame retardant function. In some more preferred embodiments of the present invention, the bottom base fabric used can be selected from composite fiber fabrics of one or more of flame retardant polyester fiber, flame retardant nylon, flame retardant acrylic fiber, flame retardant vinylon, flame retardant chloroprene fiber, flame retardant spandex, and flame retardant aramid fiber, and the processing forms include woven, knitted, non-woven, etc.

[0046] The present invention also provides a flame-retardant and heat-insulating aerogel-coated textile prepared by the above-mentioned preparation method, and the flame-retardant and heat-insulating aerogel-coated textile of the present invention comprises a bottom base fabric and an aerogel composite coating loaded on the bottom base fabric.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The present invention uses aerogel powder obtained by doping ceramic aerogel powder with expanded graphite as one of the raw materials for preparing the coating. By introducing expanded graphite into the aerogel network of the ceramic aerogel powder, not only can the thermal insulation and protection performance of the aerogel be improved, but the introduced expanded graphite can also maintain the aerogel pore structure through decomposition and vaporization processes in a high-temperature environment and remove heat, thereby improving the thermal protection and thermal stability of the overall material.

[0049] The present invention utilizes a unique expanded graphite-aerogel structural design and slurry formulation to enable the aerogel composite coating material of the present invention to effectively avoid the carbonization of the coating material in a high-temperature working environment, which would cause the aerogel structure to collapse and prevent the effective high-temperature thermal protection from occurring.

[0050] The present invention combines the aerogel composite coating material with an underlying base fabric to form a flame-retardant and thermally insulating aerogel-coated textile by coating and then curing. This method features a simple preparation process, low energy consumption, and high slurry utilization, enabling green production. Furthermore, the flame-retardant and thermally insulating aerogel-coated textile exhibits excellent flame retardancy and thermal insulation properties, and the aerogel structure is stable, suggesting broad application prospects in thermal protection applications such as arc heat and high-temperature heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a scanning electron microscope image of the flame retardant and thermal insulating aerogel coated textile of Example 8. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present invention will be described clearly and completely below. It should be noted that in the following embodiments of the present invention, the water-based polyurethane used is the water-based polyurethane resin AH-1720A produced by Anhui Dawei Huatai New Material Technology Co., Ltd., the water-based polyacrylate used is Bayhydrol A2770 produced by Guangzhou Haoyi New Material Technology Co., Ltd., the foaming agent used is L580 produced by Changzhou Zhuolian Zhichuang Polymer Materials Co., Ltd., the foam stabilizer used is SKD-550 produced by Tongxiang Haotian Chemical Co., Ltd., and the dispersant used is 5040 dispersant produced by Guangzhou Runhong Chemical Co., Ltd.

[0053] Example 1

[0054] This embodiment provides an aerogel composite coating material, which is prepared by the following steps:

[0055] 1) Preparation of expanded graphite powder:

[0056] The expanded graphite was dried in an oven at 85° C., ball-milled, passed through a 300-mesh sieve, ball-milled again, passed through a 500-mesh sieve, ball-milled again, further passed through a 1500-mesh sieve, washed, and dried to obtain expanded graphite powder.

[0057] 2) Preparation of ceramic wet gel solution:

[0058] 100 parts of ethyl orthosilicate, 20 parts of anhydrous ethanol, 20 parts of deionized water, 5 parts of dimethylformamide, 5 parts of propylene oxide and 4 parts of aqueous ammonia were mixed to obtain a ceramic wet gel solution.

[0059] 3) Mixing expanded graphite powder and ceramic wet gel solution:

[0060] The expanded graphite powder obtained above was mixed with the ceramic wet gel solution obtained above at a mixing mass / volume ratio of 1 g:100 mL, and ultrasonically stirred for 2 h to obtain a mixture.

[0061] 4) Low temperature CO2 supercritical drying:

[0062] The obtained mixture was aged at 20°C for 36 hours, and then dried for 12 hours under low-temperature CO2 supercritical drying process conditions with a gel cooler temperature of 0°C, a drying temperature of 40°C, and a pressure of 12 MPa to obtain expanded graphite-doped ceramic aerogel powder.

[0063] 5) Preparation of aerogel coating slurry:

[0064] According to weight parts, 1 part of expanded graphite-doped aerogel powder, 15 parts of aqueous polyurethane, 15 parts of aqueous polyacrylate, 2 parts of polyisocyanate crosslinking agent, 8 parts of phosphate flame retardant, 2 parts of foaming agent, 3 parts of foam stabilizer, 1 part of dispersant and 10 parts of deionized water were mixed, and stirred at room temperature at 3000 r / min for 1 hour to fully foam to obtain a uniform and stable aerogel coating slurry solution, which was stored at room temperature away from light.

[0065] Example 2

[0066] This embodiment provides an aerogel composite coating material, which is prepared by the following steps:

[0067] 1) Preparation of expanded graphite powder:

[0068] The expanded graphite was dried in an oven at 85° C., ball-milled, passed through a 300-mesh sieve, ball-milled again, passed through a 500-mesh sieve, ball-milled again, further passed through a 1500-mesh sieve, washed, and dried to obtain expanded graphite powder.

[0069] 2) Preparation of ceramic wet gel solution:

[0070] 80 parts of butyl titanate, 40 parts of anhydrous ethanol, 10 parts of deionized water, 10 parts of dimethylformamide, 2 parts of propylene oxide and 2 parts of aqueous ammonia were mixed to obtain a ceramic wet gel solution.

[0071] 3) Mixing expanded graphite powder and ceramic wet gel solution:

[0072] The expanded graphite powder obtained above was mixed with the ceramic wet gel solution obtained above at a mixing mass / volume ratio of 1 g:1000 mL, and ultrasonically stirred for 2 h to obtain a mixture.

[0073] 4) Low temperature CO2 supercritical drying:

[0074] The mixture obtained above was aged at 60°C for 6 hours, and then dried for 6 hours under low-temperature CO2 supercritical drying process conditions with a gel cooler temperature of -3°C, a drying temperature of 30°C, and a pressure of 8 MPa to obtain expanded graphite-doped ceramic aerogel powder.

[0075] 5) Preparation of aerogel coating slurry:

[0076] According to weight parts, 20 parts of expanded graphite-doped aerogel powder, 40 parts of waterborne polyurethane, 40 parts of waterborne polyacrylate, 6 parts of aziridine crosslinking agent, 15 parts of cyanate flame retardant, 5 parts of foaming agent, 8 parts of foam stabilizer, 2 parts of dispersant and 20 parts of deionized water were mixed, and stirred at room temperature at 3000 r / min for 1 hour to fully foam to obtain a uniform and stable aerogel coating slurry solution, which was stored at room temperature away from light.

[0077] Example 3

[0078] This embodiment provides an aerogel composite coating material, which is prepared by the following steps:

[0079] 1) Preparation of expanded graphite powder:

[0080] The expanded graphite was dried in an oven at 85° C., ball-milled, passed through a 300-mesh sieve, ball-milled again, passed through a 500-mesh sieve, ball-milled again, further passed through a 1500-mesh sieve, washed, and dried to obtain expanded graphite powder.

[0081] 2) Preparation of ceramic wet gel solution:

[0082] Mix 90 parts of hydrated aluminum nitrate, 30 parts of anhydrous ethanol, 15 parts of deionized water, 8 parts of dimethylformamide, 3 parts of propylene oxide and 3 parts of aqueous ammonia to obtain a ceramic wet gel solution.

[0083] 3) Mixing expanded graphite powder and ceramic wet gel solution:

[0084] The expanded graphite powder obtained above was mixed with the ceramic wet gel solution obtained above at a mixing mass / volume ratio of 1 g:500 mL, and ultrasonically stirred for 2 h to obtain a mixture.

[0085] 4) Low temperature CO2 supercritical drying:

[0086] The obtained mixture was aged at 40°C for 24 hours, and then dried for 24 hours under low-temperature CO2 supercritical drying process conditions with a gel cooler temperature of 3°C, a drying temperature of 55°C, and a pressure of 15 MPa to obtain expanded graphite-doped ceramic aerogel powder.

[0087] 5) Preparation of aerogel coating slurry:

[0088] According to weight parts, 10 parts of expanded graphite-doped aerogel powder, 20 parts of waterborne polyurethane, 25 parts of waterborne polyacrylate, 4 parts of polycarbodiimide crosslinking agent, 10 parts of silicate flame retardant, 3 parts of foaming agent, 6 parts of foam stabilizer, 2 parts of dispersant and 15 parts of deionized water were mixed, and stirred at room temperature at 3000 r / min for 1 hour to fully foam to obtain a uniform and stable aerogel coating slurry solution, which was stored at room temperature away from light.

[0089] Example 4

[0090] This embodiment provides an aerogel composite coating material, which is prepared by the following steps:

[0091] 1) Preparation of expanded graphite powder:

[0092] The expanded graphite was dried in an oven at 85° C., ball-milled, passed through a 300-mesh sieve, ball-milled again, passed through a 500-mesh sieve, ball-milled again, further passed through a 1500-mesh sieve, washed, and dried to obtain expanded graphite powder.

[0093] 2) Preparation of ceramic wet gel solution:

[0094] Mix 95 parts of ethyl orthosilicate, 25 parts of anhydrous ethanol, 10 parts of deionized water, 6 parts of dimethylformamide, 3 parts of propylene oxide and 2 parts of aqueous ammonia to obtain a ceramic wet gel solution.

[0095] 3) Mixing expanded graphite powder and ceramic wet gel solution:

[0096] The expanded graphite powder obtained above was mixed with the ceramic wet gel solution obtained above at a mixing mass / volume ratio of 1 g:800 mL, and ultrasonically stirred for 2 h to obtain a mixture.

[0097] 4) Low temperature CO2 supercritical drying:

[0098] The obtained mixture was aged at 50°C for 18 hours, and then dried for 12 hours under low-temperature CO2 supercritical drying process conditions with a gel cooler temperature of 0°C, a drying temperature of 40°C, and a pressure of 10 MPa to obtain expanded graphite-doped ceramic aerogel powder.

[0099] 5) Preparation of aerogel coating slurry:

[0100] According to weight parts, 20 parts of expanded graphite-doped aerogel powder, 15 parts of aqueous polyurethane, 40 parts of aqueous polyacrylate, 2 parts of polycarbodiimide crosslinking agent, 15 parts of silicate flame retardant, 5 parts of foaming agent, 6 parts of foam stabilizer, 2 parts of dispersant and 20 parts of deionized water were mixed, and stirred at room temperature at 3000 r / min for 1 hour to fully foam to obtain a uniform and stable aerogel coating slurry solution, which was stored at room temperature away from light.

[0101] Example 5

[0102] This embodiment provides a flame-retardant and heat-insulating aerogel-coated textile, which is prepared by the following steps:

[0103] The aerogel coating slurry solution obtained in Example 1 was applied to the surface of the underlying base fabric by a blade coating method, and then cured at 160°C for 10 minutes to solidify the slurry-like aerogel composite coating material on the surface of the underlying base fabric and form an aerogel composite coating layer to obtain a flame-retardant and heat-insulating aerogel coated textile.

[0104] In this embodiment, the base fabric weight is 150g / m 2 , coating weight 100g / m 2 .

[0105] Example 6

[0106] This embodiment provides a flame-retardant and heat-insulating aerogel-coated textile, which is prepared by the following steps:

[0107] The aerogel coating slurry solution obtained in Example 3 was applied to the surface of the underlying base fabric by a blade coating method, and then cured at 100°C for 20 minutes to solidify the slurry-like aerogel composite coating material on the surface of the underlying base fabric and form an aerogel composite coating layer to obtain a flame-retardant and heat-insulating aerogel coated textile.

[0108] In this embodiment, the base fabric weight is 150g / m 2 , coating weight 5g / m 2 .

[0109] Example 7

[0110] This embodiment provides a flame-retardant and heat-insulating aerogel-coated textile, which is prepared by the following steps:

[0111] The aerogel coating slurry solution obtained in Example 4 was applied to the surface of the underlying base fabric by a blade coating method, and then cured at 120°C for 15 minutes to cure the slurry-like aerogel composite coating material on the surface of the underlying base fabric and form an aerogel composite coating layer to obtain a flame-retardant and heat-insulating aerogel coated textile.

[0112] In this embodiment, the base fabric weight is 150g / m 2 , coating weight 40g / m 2 .

[0113] Example 8

[0114] This embodiment provides a flame-retardant and heat-insulating aerogel-coated textile, which is prepared by the following steps:

[0115] The aerogel coating slurry solution obtained in Example 4 was applied to the surface of the underlying base fabric by a blade coating method, and then cured at 140°C for 15 minutes to cure the slurry-like aerogel composite coating material on the surface of the underlying base fabric and form a layer of aerogel composite coating to obtain a flame-retardant and heat-insulating aerogel coated textile.

[0116] In this embodiment, the base fabric weight is 150g / m 2 , coating weight 70g / m 2 .

[0117] Comparative Example 1

[0118] This comparative example provides an aerogel composite coating material, which is prepared by the following steps:

[0119] 1) Preparation of ceramic wet gel solution:

[0120] 100 parts of ethyl orthosilicate, 20 parts of anhydrous ethanol, 20 parts of deionized water, 5 parts of dimethylformamide, 5 parts of propylene oxide and 4 parts of aqueous ammonia were mixed to obtain a ceramic wet gel solution.

[0121] 2) Low temperature CO2 supercritical drying:

[0122] The ceramic wet gel solution obtained above was aged at 20°C for 36 hours, and then dried for 12 hours under low-temperature CO2 supercritical drying process conditions with a gel cooler temperature of 0°C, a drying temperature of 40°C, and a pressure of 10 MPa to obtain ceramic aerogel powder.

[0123] 3) Preparation of aerogel coating slurry:

[0124] According to weight parts, 1 part of ceramic aerogel powder, 15 parts of waterborne polyurethane, 15 parts of waterborne polyacrylate, 2 parts of polyisocyanate crosslinking agent, 8 parts of phosphate flame retardant, 2 parts of foaming agent, 3 parts of foam stabilizer, 1 part of dispersant and 10 parts of deionized water were mixed, and stirred at room temperature at 3000 r / min for 1 hour to fully foam to obtain a uniform and stable aerogel coating slurry solution, which was stored at room temperature away from light.

[0125] That is, the key difference between this comparative example and Example 1 is that:

[0126] In this comparative example, no expanded graphite was added.

[0127] Comparative Example 2

[0128] This comparative example provides an aerogel composite coating material, which is prepared by the following steps:

[0129] According to weight parts, 15 parts of waterborne polyurethane, 15 parts of waterborne polyacrylate, 2 parts of polyisocyanate crosslinking agent, 8 parts of phosphate flame retardant, 2 parts of foaming agent, 3 parts of foam stabilizer, 1 part of dispersant and 10 parts of deionized water were mixed, and stirred at 3000 r / min at room temperature for 1 hour to fully foam to obtain a uniform and stable aerogel coating slurry solution, which was stored at room temperature away from light.

[0130] That is, the key difference between this comparative example and Example 1 is that:

[0131] In this comparative example, no expanded graphite-doped ceramic aerogel powder was added.

[0132] Comparative Example 3

[0133] This comparative example provides a flame retardant and heat insulating aerogel coated textile, which is prepared by the following steps:

[0134] The aerogel coating slurry solution obtained in Comparative Example 1 was applied to the surface of the underlying base fabric by a blade coating method, and then cured at 140°C for 15 minutes to cure the slurry-like aerogel composite coating material on the surface of the underlying base fabric and form a layer of aerogel composite coating to obtain a flame retardant and heat-insulating aerogel coated textile.

[0135] In this comparative example, the base fabric weight is 150g / m 2 , coating weight 100g / m 2 .

[0136] Comparative Example 4

[0137] This comparative example provides a flame retardant and heat insulating aerogel coated textile, which is prepared by the following steps:

[0138] The aerogel coating slurry solution obtained in Comparative Example 2 was applied to the surface of the underlying base fabric by a blade coating method, and then cured at 140°C for 15 minutes to cure the slurry-like aerogel composite coating material on the surface of the underlying base fabric and form a layer of aerogel composite coating to obtain a flame retardant and heat-insulating aerogel coated textile.

[0139] In this comparative example, the base fabric weight is 150g / m 2 , coating weight 100g / m 2 .

[0140] Experimental part

[0141] (1) Heat penetration performance test

[0142] The present invention takes the flame retardant and heat insulating aerogel coated textiles obtained in Examples 5 to 8 and Comparative Examples 3 and 4 as examples, and tests their heat penetration properties, respectively. The test results are shown in Table 1.

[0143] The present invention adopts the following method to test the heat penetration performance:

[0144] The coated textile was placed on a heated substrate at 90°C and the time required for the surface penetration temperature to reach 80°C was calculated to evaluate the heat penetration performance.

[0145] Table 1 Thermal penetration performance test results

[0146] Example 5 Example 6 Example 7 Example 8 Comparative Example 3 Comparative Example 4 Heat penetration performance / s 6.8 3.8 5.6 9.8 2.8 1.9

[0147] As can be seen from the test results in Table 1, Example 8 exhibits the best heat penetration shielding performance, indicating that the appropriate amount of expanded graphite-doped ceramic aerogel powder and a certain coating thickness provide it with excellent low thermal conductivity and significantly reduce the heat penetration time. In addition, although the coating thickness of Example 6 is only 5g / m2, it still exhibits better heat shielding performance than Comparative Examples 3 and 4, verifying the key role of expanded graphite-doped ceramic aerogel powder in the heat shielding protection of the present invention.

[0148] (2) Afterburning time test

[0149] The present invention takes the flame retardant and heat insulating aerogel coated textiles obtained in Examples 5 to 8 and Comparative Examples 3 and 4 as examples, and tests their afterflame time, and the test results are shown in Table 2.

[0150] Table 2 Afterburning time test results

[0151] Example 5 Example 6 Example 7 Example 8 Comparative Example 3 Comparative Example 4 Afterburning time / s 0 0 0 0 3.5 8.6

[0152] The present invention adopts the following method to test the afterburning time:

[0153] The sample to be tested should be placed vertically, that is, the length direction of the sample to be tested is perpendicular to the horizontal line. The combustion source is ignited below the sample to be tested. After the combustion source is removed, the after-flaming time of the sample to be tested is counted to evaluate the flame retardant performance through the after-flaming time.

[0154] It can be seen from the test results in Table 2 that the comparative samples lacking expanded graphite or containing expanded graphite doped with ceramic aerogel powder exhibited a longer afterflame time, demonstrating poor high-temperature flame retardancy.

[0155] (3) Arc thermal protection performance test

[0156] The flame-retardant and heat-insulating aerogel-coated textiles obtained in Examples 5 to 8 and Comparative Examples 3 and 4 were used as examples to test their arc heat protection performance according to the test method in standard ASTM F1959. The test results are shown in Table 3.

[0157] Table 3 Arc thermal protection performance test results

[0158] Example 5 Example 6 Example 7 Example 8 Comparative Example 3 Comparative Example 4 <![CDATA[Arc thermal protection performance value (cal / cm 2 )]]> 18.7 8.4 15.9 25.8 7.6 5.1

[0159] From the test results in Table 3, it can be seen that the arc thermal protection performance and the heat penetration performance time results are relatively consistent and corresponding. Example 8 has the best arc thermal protection performance resin, indicating that its appropriate amount of expanded graphite doped ceramic aerogel powder and a certain coating thickness provide it with excellent thermal protection performance and improve the arc thermal protection performance value; In addition, although the coating thickness of Example 6 is only 5g / m 2 However, it still shows better thermal protection performance than Comparative Example 3 and Comparative Example 4, verifying the key role of expanded graphite-doped ceramic aerogel powder in the thermal protection performance of the present invention.

[0160] In summary, the flame-retardant and thermal-insulating aerogel-coated textiles obtained in the present invention are significantly better than the control samples in tests such as heat penetration performance, afterburning time, and arc thermal protection performance value.

[0161] The present invention also takes the flame retardant and heat insulating aerogel coated textile of Example 8 as an example and performs a scanning electron microscope test on it, and the test results are as follows: Figure 1 As shown, it can be seen that the surface of the flame-retardant and heat-insulating aerogel-coated textile of Example 8 has a large number of aerogel particles and expanded graphite is embedded in the coating. This structure can effectively block heat and achieve thermal protection function.

[0162] Obviously, the above embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. An aerogel composite coating material for thermal protective textiles, characterized in that: Its preparation raw materials are composed of the following components by weight: 1-20 parts of aerogel powder, 15-40 parts of waterborne polyurethane, 15-40 parts of waterborne polyacrylate, 2-6 parts of crosslinking agent, 8-15 parts of flame retardant, 2-5 parts of foaming agent, 3-8 parts of foam stabilizer, 1-2 parts of dispersant and 10-20 parts of water; The aerogel powder is obtained by doping expanded graphite with ceramic aerogel powder; Wherein, the ceramic aerogel powder is one or more of silicon oxide aerogel powder, aluminum oxide aerogel powder and titanium oxide aerogel powder; The aerogel powder is prepared by the following steps: After drying the expanded graphite, grinding is performed until the flake diameter is less than 30 μm to obtain expanded graphite powder; preparing a ceramic wet gel solution corresponding to the ceramic aerogel powder; Mixing the expanded graphite powder and the ceramic wet gel solution to obtain a mixture; The mixture is subjected to an aging treatment at 20° C. to 60° C., and then subjected to a low-temperature CO2 supercritical drying treatment to obtain expanded graphite-doped ceramic aerogel powder; The ceramic wet gel solution is composed of the following components in parts by weight: 80-100 parts of inorganic source, 20-40 parts of anhydrous ethanol, 10-20 parts of deionized water, 5-10 parts of dimethylformamide, 2-5 parts of propylene oxide and 2-4 parts of ammonia water; The inorganic source is one or more of tetraethyl orthosilicate, hydrated aluminum nitrate and butyl titanate.

2. The aerogel composite coating material according to claim 1, wherein The usage ratio of the expanded graphite powder to the ceramic wet gel solution is 1 g:100 mL to 1000 mL.

3. The aerogel composite coating material according to claim 1, wherein The process parameters of the low-temperature CO2 supercritical drying process are: The temperature of the gel cooler is -3℃~3℃; The drying temperature is 30℃~55℃, the pressure is 8MPa~15MPa, and the time is 6h~24h.

4. The aerogel composite coating material according to claim 1, wherein The aging treatment time is 6h~36h.

5. A method for preparing the aerogel composite coating material according to any one of claims 1 to 4, characterized in that: The following steps are involved: According to the ratio of the aerogel composite coating material, weigh the corresponding mass of each preparation raw material and set aside; The weighed aerogel powder, waterborne polyurethane, waterborne polyacrylate, crosslinking agent, flame retardant, foaming agent, foam stabilizer, dispersant and water are mixed, and stirred at room temperature until foaming to obtain a slurry-like aerogel composite coating material.

6. Use of the aerogel composite coating material according to any one of claims 1 to 5 in the preparation of thermal protective textiles.

7. A method for preparing flame-retardant and heat-insulating aerogel-coated textiles, characterized in that: The following steps are involved: According to the ratio of the aerogel composite coating material according to any one of claims 1 to 5, weigh the corresponding mass of each preparation raw material and set aside; The aerogel powder, waterborne polyurethane, waterborne polyacrylate, crosslinking agent, flame retardant, foaming agent, foam stabilizer, dispersant and water are mixed and stirred at room temperature until foaming occurs to obtain a slurry-like aerogel composite coating material; The slurry-like aerogel composite coating material is applied to the surface of the underlying base fabric by a blade coating method, and then cured at 100° C. to 160° C. to solidify the slurry-like aerogel composite coating material on the surface of the underlying base fabric and form an aerogel composite coating layer, thereby obtaining the flame-retardant and heat-insulating aerogel coated textile. The scraping amount of the slurry-like aerogel composite coating material is 5 g / m 2 ~100g / m 2 .

8. A flame-retardant and heat-insulating aerogel-coated textile prepared by the preparation method according to claim 7.

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