Aerogel composite

Abstract

The present invention relates to an aerogel composite which can be used as a thermal insulation material in batteries, electronic devices, automobiles, industrial devices, structures, and the like, and which can maintain an excellent thermal insulation level even when subjected to compressive deformation due to pressure applied by various reasons.

Description

TECHNICAL FIELD

[0001] This application claims priority to Korean Patent Application No. 10-2023-0083943 filed on June 29, 2023, Korean Patent Application No. 10-2023-0097729 filed on July 26, 2023, and U.S. Patent Application Nos. 18 / 386,103 and 18 / 386,108 filed on November 1, 2023, the entire contents of which are incorporated by reference in their entirety.

[0002] The present invention relates to an aerogel composite and its application use as a thermal insulation material. BACKGROUND

[0003] An aerogel is an ultra-porous high specific surface area (≥ 500 m 2 / g) material having a porosity of about 90.0% to 99.9% and a pore diameter of 1 nm to 100 nm, and is a material having excellent properties such as ultra-light weight / ultra-thermal insulation / ultra-low dielectric, etc. Therefore, research on the development of aerogel materials and research on the application use thereof as a transparent thermal insulation material and an environmentally friendly high-temperature thermal insulation material, an ultra-low dielectric thin film for highly integrated devices, a catalyst and a catalyst carrier, an electrode for supercapacitors, and an electrode material for seawater desalination have been actively conducted.

[0004] The greatest advantage of an aerogel is that it has ultra-thermal insulation performance exhibiting a thermal conductivity of about 0.300 W / m·K or less, which is lower than that of a conventional organic thermal insulation material such as foamed polystyrene, thereby solving problems associated with the conventional organic thermal insulation material such as flame vulnerability and generation of harmful gases in the case of fire.

[0005] In general, an aerogel is produced by preparing a hydrogel from a silica precursor such as water glass and an alkoxysilane group (TEOS, TMOS, MTMS, etc.) and removing a liquid component within the hydrogel without destroying the microstructure.

[0006] In particular, the hydrophobic silica aerogel covering layer in which a hydrophobic silica aerogel is formed in the fibers is a functional thermal insulation material that prevents moisture corrosion and is widely used in the building or industrial fields, and in addition, the hydrophobic silica aerogel covering layer can be used as a thermal insulation material, an insulating material, or a non-flammable material for aircrafts, ships, automobiles, batteries, etc. However, when the silica aerogel covering layer is applied to the above-mentioned uses, there is a problem that the aerogel structure collapses when a pressurized environment is provided due to continuous thermal expansion of a device placed adjacent thereto, or when a large pressure is applied from the surrounding environment during installation of the aerogel thermal insulation material, so that the thermal insulation properties are significantly reduced. SUMMARY

[0007] TECHNICAL PROBLEM

[0008] The present application provides an aerogel composite that can maintain constant thermal insulation properties without significant deterioration even when exposed to a pressurized environment.

[0009] However, the technical tasks to be achieved by the present application are not limited to the above-mentioned tasks, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

[0010] Technical solution

[0011] According to some embodiments of the present application, the aerogel composite includes a fibrous base material and an aerogel including one or more pores, wherein when the aerogel composite is compressed by applying a pressure of any one of 24 bar, 30 bar, or 33 bar in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression is not more than 3 times the heat transfer coefficient before compression.

[0012] When the aerogel composite is compressed by applying a pressure of 24 bar, 30 bar, or 33 bar in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression can be greater than 1 times the heat transfer coefficient before compression, and not more than 3 times the heat transfer coefficient before compression.

[0013] When the aerogel composite is compressed by applying a pressure of 3 bar, 9 bar, or 24 bar, respectively, in a horizontal direction (transverse direction) with respect to the aerogel composite, the heat transfer coefficient after compression can be greater than 1 times the heat transfer coefficient before compression, and not more than 1.8 times the heat transfer coefficient before compression.

[0014] When a pressure of 3 bar is applied to the aerogel composite in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression can be not more than 1.45 times the heat transfer coefficient before compression. When a pressure of 3 bar is applied to the aerogel composite in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression can be equal to the heat transfer coefficient before compression or not more than 1.45 times the heat transfer coefficient before compression.

[0015] When a pressure of 9 bar is applied to the aerogel composite in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression can be not more than 1.85 times the heat transfer coefficient before compression. When a pressure of 9 bar is applied to the aerogel composite in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression can be equal to the heat transfer coefficient before compression or not more than 1.85 times the heat transfer coefficient before compression.

[0016] The heat transfer coefficient after compression can be no more than 2.35 times the heat transfer coefficient before compression when a pressure of 15 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite. The heat transfer coefficient after compression can be equal to the heat transfer coefficient before compression or no more than 2.35 times the heat transfer coefficient before compression when a pressure of 15 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite.

[0017] The compression recovery rate represented by Equation 1 below can be 60% or more when a pressure of at least one of 9 bar, 15 bar, 24 bar, 30 bar, or 33 bar is applied to the cross section of the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite.

[0018] [Equation 1]

[0019] Compression recovery rate (%) = {(cross-sectional thickness of the aerogel composite after compression) / (cross-sectional thickness of the aerogel composite before compression)} × 100

[0020] The compression recovery rate represented by Equation 1 can be 60% to 99%, 60% to 98%, 60% to 97%, 60% to 96%, or 60% to 95% when a pressure of at least one of 9 bar, 15 bar, 24 bar, 30 bar, or 33 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite.

[0021] The compression recovery rate represented by Equation 1 above can be 60% or more when a pressure of 3 bar, 9 bar, and 24 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, respectively.

[0022] The heat transfer coefficient obtained after the aerogel composite is compressed at a pressure of at least one of 3 bar, 9 bar, 15 bar, 24 bar, or 30 bar satisfies Equation 3 below.

[0023] [Equation 3]

[0024] (heat transfer coefficient after compression (a) - average value (b) of heat transfer coefficient after compression) = (average value (b) of heat transfer coefficient after compression) × A

[0025] In the above Formula 3, the heat transfer coefficient after compression (a) refers to a heat transfer coefficient obtained after compressing the aerogel composite in the horizontal direction (lateral direction) with respect to the cross section of the aerogel composite at any one of 9 bar, 15 bar, 24 bar, or 30 bar, the average of the heat transfer coefficient after compression (b) refers to an average of heat transfer coefficients obtained after compressing the aerogel composite in the horizontal direction (lateral direction) with respect to the cross section of the aerogel composite at 9 bar, 15 bar, 24 bar, and 30 bar, respectively, and A is a rational number of -0.15 to +0.15.

[0026] In Formula 3, the heat transfer coefficient after compression (a) refers to a heat transfer coefficient obtained after compressing the aerogel composite in the horizontal (lateral) direction with respect to the cross section of the aerogel composite at 3 bar, 9 bar, or 24 bar, the average of the heat transfer coefficient after compression (b) refers to an average of heat transfer coefficients obtained after compressing the aerogel composite in the horizontal (lateral) direction with respect to the cross section at 3 bar, 9 bar, and 24 bar, and A can be a rational number of -0.25 to +0.25.

[0027] The heat transfer coefficient of the aerogel composite before and after compression can satisfy the following Formula 4:

[0028] [Formula 4]

[0029] (Heat transfer coefficient before and after compression (c) - Average of heat transfer coefficient before and after compression (d)) = (Average of heat transfer coefficient before and after compression (d)) × D

[0030] In Formula 4, the heat transfer coefficient before and after compression (c) refers to a heat transfer coefficient obtained after compressing the aerogel composite in the lateral direction at 0 bar, 3 bar, 9 bar, or 24 bar, the average of the heat transfer coefficient before and after compression (d) refers to an average of heat transfer coefficients obtained after compressing the aerogel composite in the lateral direction at 0 bar, 3 bar, 9 bar, and 24 bar, respectively, and D can be a rational number of -0.25 to +0.25.

[0031] For the aerogel composite, the rate of change (B) of the heat transfer coefficient after compression per unit of applied pressure represented by the following Formula 5 can be a rational number of -0.10 to +0.10.

[0032] [Formula 5]

[0033] B = (Heat transfer coefficient after compression at x bar - Heat transfer coefficient after compression at y bar) / (x - y)

[0034] In the above Formula 5, x and y are independently a pressure value (unit: bar) of any one of 3 bar, 9 bar, 15 bar, or 24 bar, and are pressure values different from each other.

[0035] The aerogel can include pores having a pore diameter of 30 nm or less, which account for 30 to 45% of the pore volume of the skeletal structure. The aerogel can include pores having a pore diameter of 0.1 nm to 30 nm, which account for 30 to 45% of the pore volume of the skeletal structure.

[0036] The density of the aerogel composite can be 0.05 g / cm 3 to 0.50 g / cm 3 .

[0037] According to some embodiments of the present application, the thermal insulation member includes the aerogel composite provided in the present application.

[0038] The thermal insulation member can further include a support member disposed on at least one of the upper surface or the lower surface of the aerogel composite.

[0039] Advantageous effects

[0040] When used as a thermal insulation material for a battery, an electronic device, an automobile, an industrial device, a structure, or the like, the aerogel composite provided in the present application can maintain an excellent level of thermal insulation properties without being significantly deteriorated even when compressed and deformed due to a pressure applied to the aerogel composite as a result of expansion or other reasons of various devices or structures placed adjacent thereto.

[0041] Best mode

[0042] According to some embodiments of the present application, the aerogel composite includes a fibrous base material and an aerogel including one or more pores, wherein when the aerogel composite is compressed by applying a pressure of 24 bar, 30 bar, and 33 bar, respectively, in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression is not more than 3 times the heat transfer coefficient before compression.

[0043] When the aerogel composite is compressed by applying a pressure of 3 bar, 9 bar, and 24 bar, respectively, in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression can be not more than 1.8 times the heat transfer coefficient before compression.

[0044] When the aerogel composite is compressed by applying a pressure of 24 bar, 30 bar, and 33 bar, respectively, in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression can be greater than 1 times the heat transfer coefficient before compression, and not more than 3 times the heat transfer coefficient before compression.

[0045] When the aerogel composite is compressed by applying a pressure of 3 bar, 9 bar, and 24 bar, respectively, in a horizontal direction (transverse direction) with respect to a cross section of the aerogel composite, the heat transfer coefficient after compression can be greater than 1 times the heat transfer coefficient before compression, and not more than 1.8 times the heat transfer coefficient before compression.

[0046] When a pressure of 3 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be no more than 1.45 times the heat transfer coefficient before compression.

[0047] When a pressure of 9 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be no more than 1.85 times the heat transfer coefficient before compression.

[0048] When a pressure of 15 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be no more than 2.35 times the heat transfer coefficient before compression.

[0049] When a pressure of 9 bar, 15 bar, 24 bar, 30 bar, or 33 bar is applied to the cross section of the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the compression recovery rate represented by the following Formula 1 can be 60% or more:

[0050] [Formula 1]

[0051] Compression recovery rate (%) = {(cross-sectional thickness of the aerogel composite after compression) / (cross-sectional thickness of the aerogel composite before compression)} x 100

[0052] When a pressure of 3 bar, 9 bar, and 24 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, respectively, the compression recovery rate represented by Formula 1 can be 60% or more.

[0053] The heat transfer coefficient obtained after compressing the aerogel composite at a pressure of 3 bar, 9 bar, 15 bar, 24 bar, or 30 bar can satisfy the following Formula 3.

[0054] [Formula 3]

[0055] (heat transfer coefficient after compression (a) - average value of heat transfer coefficient after compression (b)) = (average value of heat transfer coefficient after compression (b)) x A

[0056] In the above Formula 3, the heat transfer coefficient after compression (a) refers to the heat transfer coefficient obtained after compressing the aerogel composite at any one of the pressure values of 9 bar, 15 bar, 24 bar, or 30 bar in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the average value of the heat transfer coefficient after compression (b) refers to the average value of the heat transfer coefficients obtained after compressing the aerogel composite at the pressures of 9 bar, 15 bar, 24 bar, and 30 bar in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, respectively, and A is a rational number of -0.15 to +0.15.

[0057] In the above Formula 3, the heat transfer coefficient after compression (a) refers to a heat transfer coefficient obtained after compressing the aerogel composite in the horizontal (transverse) direction with respect to the cross-section of the aerogel composite at a pressure of 3 bar, 9 bar, or 24 bar, the average of the heat transfer coefficient before and after compression (b) refers to an average of heat transfer coefficients obtained after compressing the aerogel composite in the horizontal (transverse) direction with respect to the cross-section at pressures of 3 bar, 9 bar, and 24 bar, respectively, and A is a rational number of -0.25 to +0.25.

[0058] The heat transfer coefficient of the aerogel composite before and after compression can satisfy the following Formula 4:

[0059] [Formula 4]

[0060] (Heat transfer coefficient before and after compression (c) - Average of heat transfer coefficient before and after compression (d)) = (Average of heat transfer coefficient before and after compression (d)) × D

[0061] In Formula 4, the heat transfer coefficient before and after compression (c) refers to a heat transfer coefficient obtained after compressing the aerogel composite in the transverse direction at a pressure of 0 bar, 3 bar, 9 bar, or 24 bar, the average of the heat transfer coefficient before and after compression (d) refers to an average of heat transfer coefficients obtained after compressing the aerogel composite in the transverse direction at respective pressure values of 0 bar, 3 bar, 9 bar, and 24 bar, and D can be a rational number of -0.25 to +0.25.

[0062] For the aerogel composite, the rate of change (B) of the heat transfer coefficient after compression per unit of applied pressure represented by the following Formula 5 can be a rational number of -0.10 to +0.10.

[0063] [Formula 5]

[0064] B = (Heat transfer coefficient after compression at pressure x - Heat transfer coefficient after compression at pressure y) / (x - y)

[0065] In the above Formula 5, x and y are independently pressure values (unit: bar) of any one of 3 bar, 9 bar, 15 bar, or 24 bar, and are pressure values different from each other.

[0066] The aerogel can include pores having a pore diameter of 30 nm or less, which account for 30% to 40% of the pore volume of the skeletal structure of the aerogel.

[0067] The density of the aerogel composite can be 0.05 g / cm 3 to 0.50 g / cm 3 .

[0068] According to some embodiments of the present application, the thermal insulation member includes the aerogel composite provided in the present application.

[0069] The thermal insulation member can further include a support member disposed on at least one of the upper surface or the lower surface of the aerogel composite. DETAILED DESCRIPTION

[0070] The terms and words used in the specification and claims should not be interpreted as being limited to the commonly used meanings and dictionary definitions and should be interpreted in a manner that is most consistent with the concept of the present application based on the principle that the inventor can properly define the meaning of the terms and words to best explain the application.

[0071] According to some embodiments of the present application, the aerogel composite includes a fiber base material and an aerogel including one or more pores.

[0072] The "aerogel" includes a three-dimensional network structure in which a plurality of aerogel particles having a size of about 2 nm to 20 nm are agglomerated or combined to form a plurality of open pores.

[0073] The aerogel can be an inorganic silica aerogel formed from a silicate compound or water glass as a precursor. The aerogel can consist of silica, silylated silica, dimethylsilylated silica, trimethylsilylated silica, or a mixture thereof. The aerogel can be an aerogel in which at least a portion of SiO2 on the surface of the SiO2 network has a bond structure of Si-O-SiO2(CH3), Si-O-SiO(CH3)2, or Si-O-Si(CH3)3. The method for producing the aerogel will be described in detail below.

[0074] The "aerogel particle" is a particle in the form of a single solid unit constituting the aerogel, and can be a powder, a bead, a fine powder material, a granule, a pellet, an agglomerate, a fiber, a flake, etc., and its shape can be spherical, semi-spherical, circular, semi-circular, polygonal, cubic, rod-shaped, polyhedral, irregular, etc. The average particle diameter of the aerogel particle can be about 10 nm to 2000 nm, 10 nm to 1500 nm, or 10 nm to 1000 nm, but is not limited thereto. The average particle diameter can be measured by any means known to those skilled in the art, such as scanning electron microscopy, dynamic light scattering, optical microscopy, size exclusion, etc., but is not limited thereto.

[0075] The aerogel can have a skeletal structure including mesopores, and can include micropores or macropores in addition to the mesopores. Here, a "mesopore" is a pore having an average pore diameter of about 2 nm to about 50 nm, a "macropore" is a pore having an average pore diameter greater than about 50 nm, and a "micropore" is a pore having an average pore diameter less than about 2 nm. The aerogel can include mesopores in a volume of at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% of the pore volume of the skeletal structure. In some embodiments, the aerogel can include mesopores. In some embodiments, the aerogel can include mesopores and micropores. The pore diameter can be measured by any means known to one of ordinary skill in the art, for example, a gas adsorption experiment, mercury intrusion, capillary flow porometry, positron annihilation lifetime spectroscopy (PALS), etc., but is not limited thereto.

[0076] In the aerogel, pores having a pore diameter of 30 nm or less are not destroyed or have a low rate of destruction even when the aerogel is compressed by high pressure (for example, a pressure of 37 bar or less, 33 bar or less, or 30 bar or less). Accordingly, in the present disclosure, by including pores having a pore diameter of 30 nm or less in the aerogel at a predetermined ratio, the heat transfer coefficient of the aerogel composite can be maintained within a predetermined range even under a pressurized environment compared to before pressurization.

[0077] Specifically, the aerogel can include pores having a pore diameter of 30 nm or less, preferably 0.1 nm to 30 nm, in a volume of 25% or more, 26% or more, 27% or more, 28% or more, 29% or more, 30% or more, or 31% or more of the pore volume of the skeletal structure, and can include 50% or less, 49% or less, 48% or less, 47% or less, 46% or less, 45% or less, 44% or less, 43% or less, 41% or less, or 40% or less, preferably 25% to 45%, 25% to 40%, 30% to 45%, or 30% to 40%, of the pores, but is not limited thereto. The aerogel can include 30% to 45% of pores having a pore diameter of 30 nm or less. The aerogel can include 30% to 45% of pores having a pore diameter of 0.1 nm to 30 nm.

[0078] Further, the aerogel can include pores having a pore diameter of more than 30 nm, which account for more than 50%, more than 51%, more than 52%, more than 53%, more than 54%, more than 55%, more than 56%, more than 57%, more than 58%, more than 59%, or more than 60% of the pore volume of the skeletal structure, and can include 75% or less, 74% or less, 73% or less, 72% or less, 71% or less, 70% or less, or 69% or less, preferably 55% to 75%, 60% to 75%, 55% to 70%, or 60% to 70% of the pores, but is not limited thereto.

[0079] The aerogel can have a porosity of more than 80%, more than 85%, more than 88%, more than 89%, more than 90%, more than 91%, more than 92%, more than 93%, more than 94%, more than 95%, more than 96%, more than 97%, more than 98%, or more than 99%, preferably more than 80%, or 99.9% or less, but is not limited thereto.

[0080] The aerogel composite has a structure in which at least some of the plurality of aerogel particles are dispersed (preferably combined) on the surface of a substrate including fibers, and at the same time has a structure in which at least some of the plurality of aerogel particles are dispersed (preferably placed) in the empty space between the discrete fibers in the substrate. Examples of the above-mentioned substrate can be a discrete fiber, a film, a sheet, a web, a fiber, a porous body, a foam, a nonwoven fabric body, or a laminate of two or more layers. Further, depending on its application, the substrate can have a surface roughness formed or patterned on its surface.

[0081] The fiber substrate can be polyester, polyalkylene terephthalate, polyethylene naphthalate, polycarbonate (e.g., rayon, nylon), cotton (e.g., Lycra® manufactured by DuPont), carbon (e.g., graphite), polyacrylonitrile (PAN), oxidized PAN, non-carbonized heat-treated PAN (e.g., those manufactured by SGL Carbon), glass fiber-based materials (S-glass, 901 glass, 902 glass, 475 glass, E-glass, etc.), silica-based fibers such as quartz (e.g., Quartzel® manufactured by Saint-Gobain), Q-Fiber® felt (manufactured by Johns Manville), Saffil® (manufactured by Saffil), Durablanket® (manufactured by Unifrax), and other silica fibers, Duraback® (manufactured by Carborundum), polyaramid fibers such as Kevlar®, Nomex®, and Sontera® (all manufactured by DuPont), CONEX (manufactured by Teijin), polyolefins such as Tyvek® (manufactured by DuPont), Dyneema® (manufactured by DSM), Spectra® (manufactured by Honeywell), other polypropylene fibers such as Typar® and Xavan® (both manufactured by DuPont), fluoropolymers such as PTFE (trade name Teflon®, manufactured by DuPont), Gore-tex® (manufactured by W.L. GORE), silicon carbide fibers such as NICALCON (manufactured by COI Ceramics), ceramic fibers such as NEXTEL (manufactured by 3M), acrylic polymers, wool, silk, hemp, leather, suede fibers, PBO fibers Zylon® (manufactured by Toyobo), liquid crystal materials such as VECTAN (manufactured by Hoechst), Cambrelle fibers (manufactured by DuPont), polyurethane, polyamide, wool fibers, boron, aluminum, iron, stainless steel fibers, and other thermoplastic resins such as PEEK, PES, PET, PEK, PPS, etc., but any fiber can be used without limitation as long as it is a fiber including spaces or voids into which the aerogel can be easily inserted, thereby improving thermal insulation performance.

[0082] The thickness of the fiber substrate can be 0.5 nm to 20 mm, but is not limited thereto.

[0083] The aerogel composite can be a mixture of the fiber substrate and the aerogel from the upper surface thereof to the lower surface thereof, but is not limited thereto.

[0084] Further, at least a part of the upper surface or the lower surface of the aerogel composite, preferably the entire surface, can have a flat shape. Here, the "flat shape" means that no concave-convex portion is formed by an intentional embossing or coating process. By forming the upper surface and the lower surface of the aerogel composite to be flat as described above, it is possible to increase the ease of work for stacking a support member (e.g., a sheet) on the surface of the upper surface and the lower surface in the future, and to increase the adhesion retention rate of the support member. Further, even when the aerogel composite itself is directly used as a thermal insulation member without the support member, it is preferable in terms of reducing the frictional force with the surface of a device located in the vicinity.

[0085] The aerogel composite has excellent elasticity, flexibility, and strength, and thus, even when the aerogel composite is compressed and deformed under a pressurized environment, it has excellent elastic recovery force and can maintain a high level of thermal insulation properties.

[0086] The density of the aerogel composite can be 0.05 g / cm 3 to 0.50 g / cm 3 , 0.05 g / cm 3 to 0.35 g / cm 3 , 0.05 g / cm 3 to 0.30 g / cm 3 , 0.10 g / cm 3 to 0.30 g / cm 3 , or 0.15 g / cm 3 to 0.30 g / cm 3 , but is not limited thereto.

[0087] When a pressure of 1 bar or more, 2 bar or more, 3 bar or more, 4 bar or more, 5 bar or more, 6 bar or more, 7 bar or more, 8 bar or more, 9 bar or more, 10 bar or more, 15 bar or more, 20 bar or more, 25 bar or more, 30 bar or more, 35 bar or more, or 40 bar or more and 50 bar or less, 45 bar or less, 40 bar or less, 35 bar or less, 30 bar or less, 25 bar or less, 20 bar or less, 15 bar or less, 10 bar or less, 9 bar or less, 8 bar or less, 7 bar or less, 6 bar or less, 5 bar or less, 4 bar or less, 3 bar or less, or 2 bar or less is applied to the aerogel composite in the horizontal direction (lateral direction) with respect to the cross section of the aerogel composite, the compression recovery rate can be 45% or more, 50% or more, 55% or more, 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more.

[0088] As shown in Formula 1 below, the "compression recovery rate" refers to the percentage of the cross-sectional thickness of the aerogel composite after a predetermined time after compression with respect to the cross-sectional thickness of the aerogel composite before compression. Here, the predetermined time can be, for example, 1 second or more, 5 seconds or more, 10 seconds or more, 30 seconds or more, 1 minute or more, 5 minutes or more, 10 minutes or more, 20 minutes or more, 30 minutes or more, 40 minutes or more, 50 minutes or more, 1 hour or more, 2 hours or more, 4 hours or more, 6 hours or more, 8 hours or more, 10 hours or more, 12 hours or more, 24 hours or more, 48 hours or more, or 96 hours or more, but is not limited thereto.

[0089] [Formula 1]

[0090] Compression recovery rate (%) = {(cross-sectional thickness of aerogel composite after compression) / (cross-sectional thickness of aerogel composite before compression)} × 100

[0091] The "pressure" value refers to the pressure value actually applied to the unit area of the aerogel composite when pressure is applied in the horizontal direction (lateral direction) with respect to the cross section of the aerogel composite using a pressing device or the like. When pressure is applied in the horizontal direction (lateral direction) with respect to the cross section of the aerogel composite using a pressing device including a cylinder, the actual pressure value can refer to a value obtained by dividing the product of the cross-sectional area of the cylinder and the set pressure value by the area of the sample (as shown in Formula 2 below), but is not limited thereto and can be calculated differently according to each device or the manner set by the manufacturer.

[0092] [Formula 2]

[0093] Actual pressure value = (radius (cm) of pressing device cylinder inner diameter × radius (cm) of pressing device cylinder inner diameter × 3.14 × set pressure value) / (area (cm 2 ))

[0094] In Formula 2 above, the unit of the radius of the cylinder inner diameter can be, for example, cm, the unit of the area of the sample can be, for example, cm 2 , and the unit of the set pressure value can be bar or kgf, but is not limited thereto.

[0095] The time for which the pressure is applied to the aerogel composite is not particularly limited, but can be, for example, 1 second or more, 5 seconds or more, 10 seconds or more, 30 seconds or more, 1 minute or more, 5 minutes or more, 10 minutes or more, 20 minutes or more, 30 minutes or more, 40 minutes or more, 50 minutes or more, 1 hour or more, or 2 hours or more and 24 hours or less, 12 hours or less, 10 hours or less, 8 hours or less, 6 hours or less, 4 hours or less, 2 hours or less, 1 hour or less, 50 minutes or less, 40 minutes or less, 30 minutes or less, 20 minutes or less, 10 minutes or less, 5 minutes or less, 1 minute or less, 30 seconds or less, 10 seconds or less, or 5 seconds or less, but is not limited thereto.

[0096] Applying pressure to the aerogel composite in the lateral direction means applying pressure to the cross section of the aerogel composite in the horizontal direction, particularly in the direction from the upper surface to the lower surface or from the lower surface to the upper surface, i.e., in the thickness direction.

[0097] When a pressure of 3 bar or more is applied to the aerogel composite in the horizontal direction (lateral direction) with respect to the cross section of the aerogel composite, the compression recovery rate can be 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more.

[0098] When a pressure of 5 bar or more, 10 bar or more, 15 bar or more, 20 bar or more, 25 bar or more, 30 bar or more, or 35 bar or more is applied to the aerogel composite in the horizontal direction (lateral direction) with respect to the cross section of the aerogel composite, the compression recovery rate can be 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more.

[0099] When a pressure of 3 bar is applied to the aerogel composite in the horizontal direction (transverse) relative to the cross-section of the aerogel composite, the compression recovery can be 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more, preferably 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, or 92% or more, and more preferably 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, or 92% or more.

[0100] When a pressure of 9 bar is applied to the aerogel composite in the horizontal direction (transverse) relative to the cross-section of the aerogel composite, the compression recovery can be 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more, preferably 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, or 92% or more, and more preferably 70% or more, 72% or more, 74% or more, 76% or more, or 78% or more.

[0101] When a pressure of 15 bar is applied to the aerogel composite in the horizontal direction (transverse) relative to the cross-section of the aerogel composite, the compression recovery can be 55% or more, 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more, preferably 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, or 92% or more, and more preferably 70% or more, 72% or more, 74% or more, or 76% or more.

[0102] The compression recovery rate can be 55% or more, 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more, preferably 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, or 92% or more, and more preferably 70% or more, 72% or more, 74% or more, or 76% or more, when a pressure of 24 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite.

[0103] The compression recovery rate can be 53% or more, 55% or more, 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more, preferably 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, or 92% or more, and more preferably 68% or more, 70% or more, 72% or more, 74% or more, or 76% or more, when a pressure of 30 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite.

[0104] When a pressure of 33 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the compression recovery rate can be 53% or more, 55% or more, 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more, preferably 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, or 92% or more, and more preferably 68% or more, 70% or more, 72% or more, 74% or more, or 76% or more.

[0105] When a pressure of 37 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the compression recovery rate can be 50% or more, 55% or more, 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, 92% or more, 94% or more, 95% or more, 96% or more, 97% or more, 98% or more, or 99% or more, preferably 55% or more, 60% or more, 62% or more, 64% or more, 66% or more, 68% or more, 70% or more, 72% or more, 74% or more, 76% or more, 78% or more, 80% or more, 82% or more, 84% or more, 86% or more, 88% or more, 90% or more, or 92% or more, and more preferably 55% or more, 60% or more, or 62% or more.

[0106] The thickness of the aerogel composite before compression can be 20 mm or less, 15 mm or less, 14 mm or less, 13 mm or less, 12 mm or less, 11 mm or less, 10 mm or less, 9 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, or 1 mm or less and 0.5 mm or more, 1 mm or more, or 2 mm or more, and the thickness can be appropriately adjusted by adjusting the thickness of the substrate or the amount of the aerogel sol impregnated into the substrate according to the application of the aerogel composite.

[0107] When a pressure of 1 bar or more, 2 bar or more, 3 bar or more, 4 bar or more, 5 bar or more, 6 bar or more, 7 bar or more, 8 bar or more, 9 bar or more, 10 bar or more, 15 bar or more, 20 bar or more, 25 bar or more, 30 bar or more, 35 bar or more, or 40 bar or more and 50 bar or less, 45 bar or less, 40 bar or less, 35 bar or less, 30 bar or less, 25 bar or less, 20 bar or less, 15 bar or less, 10 bar or less, 9 bar or less, 8 bar or less, 7 bar or less, 6 bar or less, 5 bar or less, 4 bar or less, 3 bar or less, or 2 bar or less is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 3 times or less, 2.9 times or less, 2.8 times or less, 2.7 times or less, 2.6 times or less, 2.5 times or less, 2.4 times or less, 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less and 1 times or more or more than 1 times the heat transfer coefficient before compression.

[0108] The "heat transfer coefficient" refers to heat transfer from the air layer through the solid object to the air layer, and refers to the amount of heat flowing when the cross-sectional area of 1 m 2 at a temperature difference of 1℃ per unit time, which is a value obtained by dividing the thermal conductivity of the object by the thickness of the object. The amount of heat transfer of the object is affected by the thermal conductivity and the thickness of the object, and the greater the thermal conductivity and the thinner the thickness, the greater the amount of heat transfer. Therefore, in order to achieve good thermal insulation performance, a small thermal conductivity is required, and a large thickness is required. However, when a pressure is applied to an elastic object (for example, an aerogel composite), the thermal conductivity can change after the pressure is applied, and the thickness can also change. In other words, unless the object is a completely elastic material, its thickness inevitably decreases after the pressure is applied, but if the thermal conductivity does not change, the total amount of heat transfer increases due to the decrease in thickness. In other words, it is inevitable that the thermal insulation performance will decrease. Therefore, whether the thermal insulation performance is maintained after the pressure is applied is not only confirmed by the thermal conductivity after the pressure is applied, but also by the heat transfer coefficient, which takes into account the thermal conductivity after the pressure is applied and the thickness after the pressure is applied. Even if the thermal conductivity decreases or remains after the pressure is applied, if the thickness significantly decreases after the pressure is applied, the heat transfer coefficient and the total amount of heat transfer inevitably significantly increase.

[0109] Even after the pressure is applied, the thermal conductivity and the thickness of the aerogel composite do not significantly change, so that the increase rate of the heat transfer coefficient is not high compared to before the pressure is applied, and even after the pressure is applied, the thermal insulation performance can be maintained at an excellent level without significant deterioration.

[0110] The "heat transfer coefficient after compression" refers to the ratio of the thermal conductivity measured after a predetermined time after compression to the cross-sectional thickness of the aerogel composite, by applying a certain level of pressure to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite. Here, the predetermined time can be, for example, 1 second or more, 5 seconds or more, 10 seconds or more, 30 seconds or more, 1 minute or more, 5 minutes or more, 10 minutes or more, 20 minutes or more, 30 minutes or more, 40 minutes or more, 50 minutes or more, 60 minutes or more, 2 hours or more, 4 hours or more, 6 hours or more, 8 hours or more, 10 hours or more, 12 hours or more, 24 hours or more, 48 hours or more, or 96 hours or more, but is not limited thereto.

[0111] The time for which the pressure is applied to the aerogel composite is not particularly limited, but can be, for example, 1 second or more, 5 seconds or more, 10 seconds or more, 30 seconds or more, 1 minute or more, 5 minutes or more, 10 minutes or more, 20 minutes or more, 30 minutes or more, 40 minutes or more, 50 minutes or more, 1 hour or more, or 2 hours or more and 24 hours or less, 12 hours or less, 10 hours or less, 8 hours or less, 6 hours or less, 4 hours or less, 2 hours or less, 1 hour or less, 50 minutes or less, 40 minutes or less, 30 minutes or less, 20 minutes or less, 10 minutes or less, 5 minutes or less, 1 minute or less, 30 seconds or less, 10 seconds or less, or 5 seconds or less, but is not limited thereto.

[0112] When a pressure of 3 bar or more, 5 bar or more, 10 bar or more, 15 bar or more, 20 bar or more, 25 bar or more, 30 bar or more, or 35 bar or more is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 3 times or less, 2.9 times or less, 2.8 times or less, 2.7 times or less, 2.6 times or less, 2.5 times or less, 2.4 times or less, 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression.

[0113] When a pressure of any one pressure value among 3 bar to 33 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 2.0 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression.

[0114] When a pressure of any one pressure value among 3 bar to 24 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression.

[0115] When a pressure of any one pressure value among 3 bar to 9 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression.

[0116] When a pressure of any one pressure value among 9 bar to 33 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression.

[0117] When a pressure of any one pressure value among 15 bar to 33 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, or 1.05 times or less of the heat transfer coefficient before compression.

[0118] When a pressure of any one pressure value among 15 bar to 30 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, or 1.05 times or less of the heat transfer coefficient before compression.

[0119] When a pressure of any one pressure value among 24 bar to 33 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 2.7 times or less, 2.6 times or less, 2.5 times or less, 2.4 times or less, 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, or 1.1 times or less of the heat transfer coefficient before compression.

[0120] When a pressure of any one pressure value among 24 bar to 30 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 2.7 times or less, 2.6 times or less, 2.5 times or less, 2.4 times or less, 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, or 1.1 times or less of the heat transfer coefficient before compression.

[0121] When a pressure of any one pressure value among 30 bar to 33 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 3 times or less, 2.9 times or less, 2.8 times or less, 2.7 times or less, 2.6 times or less, 2.5 times or less, 2.4 times or less, 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, or 1.1 times or less of the heat transfer coefficient before compression.

[0122] When a pressure of 3 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 1.45 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression, preferably 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less.

[0123] When a pressure of 3 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 1.45 times or less of the heat transfer coefficient before compression. When a pressure of 3 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be equal to the heat transfer coefficient before compression or 1.45 times or less of the heat transfer coefficient before compression. When a pressure of 3 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be greater than the heat transfer coefficient before compression or 1.45 times or less of the heat transfer coefficient before compression.

[0124] When a pressure of 9 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 1.85 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression, preferably 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less.

[0125] When a pressure of 9 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 1.85 times or less of the heat transfer coefficient before compression. When a pressure of 9 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be equal to the heat transfer coefficient before compression or 1.85 times or less of the heat transfer coefficient before compression. When a pressure of 9 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be greater than the heat transfer coefficient before compression or 1.85 times or less of the heat transfer coefficient before compression.

[0126] When a pressure of 15 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 2.35 times or less, 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression, preferably 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, or 1.05 times or less, and more preferably 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, or 1.1 times or less.

[0127] When a pressure of 15 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 2.35 times or less of the heat transfer coefficient before compression. When a pressure of 15 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be equal to the heat transfer coefficient before compression or 2.35 times or less of the heat transfer coefficient before compression. When a pressure of 15 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be greater than the heat transfer coefficient before compression or 2.35 times or less of the heat transfer coefficient before compression.

[0128] When a pressure of 24 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 2.7 times or less, 2.6 times or less, 2.5 times or less, 2.4 times or less, 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression, preferably 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, or 1.05 times or less, and more preferably 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, or 1.1 times or less.

[0129] When a pressure of 24 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression in the transverse direction can be no more than 2.7 times the heat transfer coefficient before compression. When a pressure of 24 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be equal to the heat transfer coefficient before compression or no more than 2.7 times the heat transfer coefficient before compression. When a pressure of 24 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be greater than the heat transfer coefficient before compression or no more than 2.7 times the heat transfer coefficient before compression.

[0130] When a pressure of 30 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 3 times less, 2.9 times less, 2.8 times less, 2.7 times less, 2.6 times less, 2.5 times less, 2.4 times less, 2.3 times less, 2.2 times less, 2.1 times less, 2 times less, 1.9 times less, 1.8 times less, 1.7 times less, 1.6 times less, 1.5 times less, 1.4 times less, 1.3 times less, 1.2 times less, 1.1 times less, 1.05 times less, 1.04 times less, 1.03 times less, 1.02 times less, or 1.01 times less than the heat transfer coefficient before compression, preferably 2.3 times less, 2.2 times less, 2.1 times less, 2 times less, 1.9 times less, 1.8 times less, 1.7 times less, 1.6 times less, 1.5 times less, 1.4 times less, 1.3 times less, 1.2 times less, 1.1 times less, or 1.05 times less, and more preferably 1.7 times less, 1.6 times less, 1.5 times less, 1.4 times less, 1.3 times less, 1.2 times less, or 1.1 times less.

[0131] When a pressure of 30 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression in the transverse direction can be no more than 3 times the heat transfer coefficient before compression. When a pressure of 30 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be equal to the heat transfer coefficient before compression or no more than 3 times the heat transfer coefficient before compression. When a pressure of 30 bar is applied to the aerogel composite in the horizontal direction (transversely) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be greater than the heat transfer coefficient before compression or no more than 3 times the heat transfer coefficient before compression.

[0132] When a pressure of 33 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 3 times or less, 2.9 times or less, 2.8 times or less, 2.7 times or less, 2.6 times or less, 2.5 times or less, 2.4 times or less, 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression, preferably 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, or 1.1 times or less, and more preferably 2.0 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, or 1.2 times or less.

[0133] When a pressure of 33 bar is applied to the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, the heat transfer coefficient after compression can be 3 times or less, 2.9 times or less, 2.8 times or less, 2.7 times or less, 2.6 times or less, 2.5 times or less, 2.4 times or less, 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, 1.1 times or less, 1.05 times or less, 1.04 times or less, 1.03 times or less, 1.02 times or less, or 1.01 times or less of the heat transfer coefficient before compression, preferably 2.3 times or less, 2.2 times or less, 2.1 times or less, 2 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, 1.2 times or less, or 1.1 times or less, and more preferably 2.0 times or less, 1.9 times or less, 1.8 times or less, 1.7 times or less, 1.6 times or less, 1.5 times or less, 1.4 times or less, 1.3 times or less, or 1.2 times or less.

[0134] When the aerogel composite is compressed by applying at least one pressure of 3 bar, 9 bar, and 24 bar in the transverse direction with respect to the aerogel composite, the heat transfer coefficient after compression can be equal to or 1.8 times or less of the heat transfer coefficient before compression.

[0135] When the aerogel composite is compressed by applying pressures of 3 bar, 9 bar, and 24 bar, respectively, in the transverse direction with respect to the aerogel composite, the heat transfer coefficient after compression can be equal to or 1.8 times or less of the heat transfer coefficient before compression.

[0136] When the aerogel composite is compressed by applying pressures of 3 bar, 9 bar, and 24 bar, respectively, in the transverse direction with respect to the aerogel composite, the heat transfer coefficient after compression can be greater than or 1.8 times or less of the heat transfer coefficient before compression.

[0137] When measuring the recovery rate or the heat transfer coefficient after compression using a compression device or the like as described above, the measurement can be performed by preparing a single sample from the aerogel composite; however, in the case where the width or length dimension of the aerogel composite is smaller than the pressure applying portion of the measurement apparatus, the measured value of the compression recovery rate or the heat transfer coefficient is considered to be substantially the same as those obtained from a single sample as follows: after cutting the aerogel composite into two or more pieces and rearranging the pieces so that both the width and the length thereof are larger than the pressure applying apparatus, the compression recovery rate or the heat transfer coefficient is measured.

[0138] The recovery rate after compression or the heat transfer coefficient after compression can be measured with respect to a rectangular aerogel composite sample having a width and a length of 20 cm x 20 cm. Here, if the width or length dimension of the produced aerogel composite is smaller than 20 cm, two or more samples can be rearranged side by side so that the dimension of the sample becomes 20 cm x 20 cm, and then the measurement can be performed with respect to the sample.

[0139] Even when the aerogel composite is pressurized (or compressed) at a pressure of any strength, the heat transfer coefficient remains within a certain range after compression, so that the thermal insulation performance can be maintained at an excellent level without being significantly deteriorated.

[0140] Specifically, the heat transfer coefficient obtained after compressing the aerogel composite at a pressure of at least one of 3 bar to 30 bar can satisfy the following Equation 3.

[0141] [Equation 3]

[0142] (Heat transfer coefficient after compression (a) - average value of heat transfer coefficient after compression (b)) = (average value of heat transfer coefficient after compression (b)) x A

[0143] In Equation 3 above, the heat transfer coefficient after compression (a) refers to the heat transfer coefficient obtained after compressing in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite at a pressure of at least one of 3 bar to 30 bar. The heat transfer coefficient after compression (a) can refer to the heat transfer coefficient obtained after compression at a pressure of 3 bar, 9 bar, 15 bar, 24 bar, or 30 bar. Alternatively, the heat transfer coefficient after compression (a) can refer to the heat transfer coefficient obtained after compression at a pressure of 3 bar, 9 bar, or 24 bar. Alternatively, the heat transfer coefficient after compression (a) can refer to the heat transfer coefficient obtained after compression at a pressure of 9 bar, 15 bar, 24 bar, or 30 bar.

[0144] Further, the average of the heat transfer coefficients after compression (b) refers to an average of the heat transfer coefficients obtained after compression at a pressure of at least two pressure values among 3 bar to 30 bar in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite. The average of the heat transfer coefficients after compression (b) can refer to an average of the heat transfer coefficients obtained after compression at a pressure of 3 bar, 9 bar, and 24 bar, respectively. Alternatively, the average of the heat transfer coefficients after compression (b) can refer to an average of the heat transfer coefficients obtained after compression at a pressure of 9 bar, 15 bar, 24 bar, and 30 bar, respectively.

[0145] A can be a rational number of -0.25 to +0.25, a rational number of -0.24 to +0.24, a rational number of -0.23 to +0.23, a rational number of -0.22 to +0.22, a rational number of -0.21 to +0.21, a rational number of -0.20 to +0.20, a rational number of -0.19 to +0.19, a rational number of -0.15 to +0.15, a rational number of -0.14 to +0.14, a rational number of -0.13 to +0.13, a rational number of -0.12 to +0.12, a rational number of -0.11 to +0.11, or a rational number of -0.10 to +0.10.

[0146] The heat transfer coefficient obtained after compression of the aerogel composite at a pressure of 9 bar, 15 bar, 24 bar, or 30 bar can satisfy the above Equation 3. At this time, in Equation 3 above, the heat transfer coefficient after compression (a) can refer to a heat transfer coefficient obtained after compression at a pressure of 9 bar, 15 bar, 24 bar, or 30 bar in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite, and the average of the heat transfer coefficients after compression (b) can refer to an average of the heat transfer coefficients obtained after compression at a pressure of any two pressure values among 9 bar, 15 bar, 24 bar, and 30 bar in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite.

[0147] The heat transfer coefficient obtained after compressing the aerogel composite at each of 9 bar, 15 bar, 24 bar, and 30 bar can satisfy the above-described Equation 3. At this time, in the above-described Equation 3, the heat transfer coefficient after compression (a) can refer to a heat transfer coefficient obtained after compressing the aerogel composite at any one of 9 bar, 15 bar, 24 bar, or 30 bar with respect to the cross section of the aerogel composite in the horizontal direction (lateral direction), and the average of the heat transfer coefficient after compression (b) can refer to an average of heat transfer coefficients obtained after compressing the aerogel composite at 9 bar, 15 bar, 24 bar, and 30 bar, respectively, with respect to the cross section of the aerogel composite in the horizontal direction (lateral direction). At this time, A can be a rational number of -0.15 to +0.15, a rational number of -0.14 to +0.14, a rational number of -0.13 to +0.13, a rational number of -0.12 to +0.12, a rational number of -0.11 to +0.11, or a rational number of -0.10 to +0.10.

[0148] The heat transfer coefficient obtained after compressing the aerogel composite at a pressure of 3 bar, 9 bar, or 24 bar can satisfy Equation 3. At this time, in Equation 3, the heat transfer coefficient after compression (a) refers to a heat transfer coefficient obtained after compressing the aerogel composite at a pressure of 3 bar, 9 bar, or 24 bar with respect to the cross section of the aerogel composite in the horizontal direction (lateral direction), and the average of the heat transfer coefficient after compression (b) can refer to an average of heat transfer coefficients obtained after compressing the aerogel composite at at least two of 3 bar, 9 bar, and 24 bar with respect to the cross section in the horizontal direction (lateral direction).

[0149] The heat transfer coefficient obtained after compressing the aerogel composite at a pressure of 3 bar, 9 bar, or 24 bar can satisfy Equation 3. At this time, in Equation 3, the heat transfer coefficient after compression (a) refers to a heat transfer coefficient obtained after compressing the aerogel composite at a pressure of 3 bar, 9 bar, or 24 bar with respect to the cross section of the aerogel composite in the horizontal direction (lateral direction), and the average of the heat transfer coefficient after compression (b) can refer to an average of heat transfer coefficients obtained after compressing the aerogel composite at at least two of 3 bar, 9 bar, and 24 bar with respect to the cross section in the horizontal direction (lateral direction).

[0150] Further, even when the aerogel composite is pressurized (or compressed) at any strength of pressure, the heat transfer coefficient is maintained within a certain range before and after compression, so that the thermal insulation performance can be maintained at an excellent level without being significantly deteriorated.

[0151] Specifically, the heat transfer coefficient obtained after compressing the aerogel composite at at least one pressure value of 0 to 24 bars can satisfy the following Equation 4:

[0152] [Equation 4]

[0153] (Heat transfer coefficient (c) before and after compression - Average value (d) of heat transfer coefficient before and after compression) = (Average value (d) of heat transfer coefficient before and after compression) × D

[0154] In Equation 4, "heat transfer coefficient (c) before and after compression" refers to a heat transfer coefficient obtained after compressing the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite at at least one pressure value of 0 to 24 bars. The heat transfer coefficient (c) before and after compression can refer to a heat transfer coefficient obtained after compressing the aerogel composite at a pressure of 0 bar, 3 bars, 9 bars, or 24 bars. Here, the pressure of 0 bar indicates a state without pressure application (uncompressed), and thus the heat transfer coefficient obtained after compression at a pressure of 0 bar indicates the heat transfer coefficient of the aerogel composite without pressure application.

[0155] Further, "average value (d) of heat transfer coefficient before and after compression" refers to an average value of heat transfer coefficients including the heat transfer coefficient of the aerogel composite without pressure application (or compression) and the heat transfer coefficients obtained after compressing the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite at at least two pressure values greater than 0 bar and equal to or less than 24 bars. The average value (d) of heat transfer coefficient before and after compression can refer to an average value of heat transfer coefficients obtained after compressing the aerogel composite at at least two pressure values of 0 bar, 3 bars, 9 bars, and 24 bars.

[0156] D can be a rational number of -0.30 to +0.30, a rational number of -0.25 to +0.25, a rational number of -0.24 to +0.24, a rational number of -0.23 to +0.23, a rational number of -0.22 to +0.22, a rational number of -0.21 to +0.21, a rational number of -0.20 to +0.20, a rational number of -0.19 to +0.19, a rational number of -0.15 to +0.15, a rational number of -0.14 to +0.14, a rational number of -0.13 to +0.13, a rational number of -0.12 to +0.12, a rational number of -0.11 to +0.11, or a rational number of -0.10 to +0.10.

[0157] The heat transfer coefficient of the aerogel composite without compression (0 bar compression) can satisfy Equation 4. At this time, the average value (d) of the heat transfer coefficients before and after compression can mean the average value of the heat transfer coefficient of the aerogel composite without compression and the heat transfer coefficients obtained after compressing the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite at at least two pressure values of 3 bar, 9 bar, and 24 bar.

[0158] The heat transfer coefficient obtained after compressing the aerogel composite at a pressure of 3 bar, 9 bar, or 24 bar can satisfy Equation 4. At this time, the average value (d) of the heat transfer coefficients before and after compression can mean the average value of the heat transfer coefficient of the aerogel composite without compression and the heat transfer coefficients obtained after compressing the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite at at least two pressure values of 3 bar, 9 bar, and 24 bar.

[0159] The average value (d) of the heat transfer coefficients before and after compression means the average value of the heat transfer coefficient of the aerogel composite without compression (0 bar compression) and the heat transfer coefficients obtained after compressing the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite at respective pressures of 3 bar, 9 bar, and 24 bar, respectively, and D can be a rational number of -0.30 to +0.30, a rational number of -0.25 to +0.25, a rational number of -0.24 to +0.24, a rational number of -0.23 to +0.23, a rational number of -0.22 to +0.22.

[0160] The average value (d) of the heat transfer coefficients before and after compression means the average value of the heat transfer coefficient of the aerogel composite without compression (0 bar compression) and the heat transfer coefficients obtained after compressing the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite at respective pressures of 3 bar, 9 bar, and 24 bar, respectively, and D can be a rational number of -0.30 to +0.30, a rational number of -0.25 to +0.25, a rational number of -0.24 to +0.24, a rational number of -0.23 to +0.23, a rational number of -0.22 to +0.22.

[0161] The heat transfer coefficient obtained after compressing the aerogel composite at a pressure of 0 bar, 3 bar, 9 bar, or 24 bar can satisfy Equation 4. Here, the average value (b) of the heat transfer coefficients before and after compression means the average value of the heat transfer coefficient of the aerogel composite without compression (0 bar compression) and the heat transfer coefficients obtained after compressing the aerogel composite in the horizontal direction (transverse direction) with respect to the cross section of the aerogel composite at at least two pressure values of 3 bar, 9 bar, and 24 bar. At this time, D can be a rational number of -0.25 to +0.25.

[0162] Further, a rate of change (B) of the heat transfer coefficient after compression per unit of applied pressure represented by the following Formula 5 for the aerogel composite can be a rational number of -0.10 or more, -0.09 or more, -0.08 or more, -0.07 or more, -0.06 or more, -0.05 or more, -0.04 or more, -0.03 or more, -0.02 or more, or -0.01 or more, and can be a rational number of +0.10 or less, +0.09 or less, +0.08 or less, +0.07 or less, +0.06 or less, +0.05 or less, +0.04 or less, +0.03 or less, +0.02 or less, or +0.01 or less. Preferably, the rate of change (B) can be a rational number of -0.10 to +0.10, a rational number of -0.09 to +0.09, a rational number of -0.08 to +0.08, a rational number of -0.07 to +0.07, a rational number of -0.06 to +0.06, or a rational number of -0.05 to +0.05.

[0163] [Formula 5]

[0164] B = (heat transfer coefficient after compression at x pressure - heat transfer coefficient after compression at y pressure) / (x - y)

[0165] In the above Formula 5, x and y are independently a pressure value (unit: bar) of any one of 3 bar to 24 bar, and are pressure values different from each other.

[0166] In the above Formula 5, x and y can be independently any one of a pressure value of 3 bar, 9 bar, 15 bar, or 24 bar.

[0167] In the above Formula 5, x can be 24 bar, and y can be 3 bar.

[0168] In the above Formula 5, x can be 24 bar, and y can be 9 bar.

[0169] In the above Formula 5, x can be 15 bar, and y can be 9 bar.

[0170] In the above Formula 5, x can be 24 bar, and y can be 15 bar.

[0171] The rate of change (B) of the heat transfer coefficient after compression per unit of applied pressure can be a rational number of -0.10 to +0.10.

[0172] The aerogel composite has a compression strength of 20 kPa to 80 kPa, 20 kPa to 70 kPa, 30 kPa to 80 kPa, 30 kPa to 70 kPa, 35 kPa to 80 kPa, or 35 kPa to 70 kPa at 10% of deformation, and can have excellent mechanical strength. Here, the compression strength can be measured by preparing a sample according to the ASTM C165 standard.

[0173] The aerogel composite has a tensile strength of 30 N / cm 2 to 60 N / cm 2 , 40 N / cm 2 to 55 N / cm 2 or 45 N / cm 2 to 55 N / cm 2 , and can have excellent flexibility. Here, the tensile strength can be measured by preparing a sample according to the ASTM D638 standard.

[0174] The aerogel composite can generally be formed by preparing a silica sol, impregnating a fibrous substrate with the silica sol, then performing gelation thereon, and drying the same. Hereinafter, each step will be described. However, the specific preparation method or examples thereof described herein should not be limited to any particular type of aerogel or preparation method thereof. The present invention can include any aerogel formed by any related preparation method known to one of ordinary skill in the art.

[0175] Preparation of silica sol

[0176] In the present invention, a silica precursor composition and a catalyst composition can be mixed to prepare a silica sol.

[0177] The silica precursor composition can include water and / or a polar organic solvent in the silica precursor.

[0178] The silica precursor can be used without limitation as long as it is a precursor that can be used to form a silica aerogel, and can be, for example, a silicon alkoxide-based compound. Specifically, the silica precursor can be a tetraalkyl orthosilicate, such as tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), methyltriethyl orthosilicate, dimethyldiethyl orthosilicate, tetrapropyl orthosilicate, tetraisopropyl orthosilicate, tetrabutyl orthosilicate, tetra-sec-butyl orthosilicate, tetra-t-butyl orthosilicate, tetrahexyl orthosilicate, tetracyclohexyl orthosilicate, and tetradodecyl orthosilicate. Among them, more specifically, the silica precursor can be tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), or a mixture thereof.

[0179] Further, the silica precursor can be a water glass solution. Here, the water glass solution can be a diluted solution in which distilled water is added to water glass and then mixed therewith; and the water glass can be sodium silicate (Na2SiO3), which is an alkali metal silicate obtained by melting silicon dioxide (SiO2) and an alkali.

[0180] Further, the silica precursor can include pre-hydrolyzed TEOS (HTEOS). HTEOS is a silicate ester oligomer material having a wide molecular weight distribution, and when synthesized from TEOS monomers in an oligomer form, can adjust physical properties such as gelation time, and thus can be easily applied according to the user's reaction conditions. In addition, there is an advantage in that reproducible physical properties of the final product can be produced. HTEOS can generally be synthesized through a condensation reaction of TEOS that undergoes a partial hydration step under acidic conditions. In other words, HTEOS is a form of an oligomer prepared by condensing TEOS, in which the oligomer is partially hydrated.

[0181] The silica precursor composition can further include a silicate including a hydrophobic group. The type of the silicate including a hydrophobic group is not limited as long as it is an alkylsilane compound including an alkyl group inducing hydrophobization and a silane functional group capable of reacting with the -Si-O- functional group of the wet gel, but specific examples thereof can include one or more selected from the group consisting of methyltriethoxysilane (MTES), trimethylethoxysilane (TMES), trimethylsilanol (TMS), methyltrimethoxysilane (MTMS), dimethyldiethoxysilane (DMDEOS), ethyltriethoxysilane (ETES), and phenyltriethoxysilane (PTES), but are not limited thereto.

[0182] When the silicate including a hydrophobic group is included in the silica precursor composition, the molar ratio of the contained silicate including a hydrophobic group and tetraalkyl silicate (molar ratio of the silicate including a hydrophobic group to the tetraalkyl silicate) can be 2:98 to 98:2. Within the above range, the strength and thermal insulation performance of the aerogel can be efficiently secured, and shrinkage can be prevented during atmospheric pressure drying, thereby preventing deterioration of the thermal insulation performance.

[0183] The silica concentration of the silica precursor composition can be 10 kg / m 3 to 100 kg / m 3 , 20 kg / m 3 to 80 kg / m 3 , 30 kg / m 3 to 70 kg / m 3 , 30 kg / m 3 to 60 kg / m 3 , or 35 kg / m 3 to 45 kg / m 3 , but is not limited thereto. The silica concentration is the concentration of the silica included in the silica precursor with respect to the silica precursor composition, and can be appropriately adjusted by changing the contents of the silica precursor, the organic solvent, and water.

[0184] The amount of the silica precursor can be such that the content of silica contained in the silica sol becomes 0.1 to 30% by weight, but is not limited thereto. When the content of silica satisfies the above range, it is preferable in terms of securing mechanical physical properties, particularly flexibility of the aerogel composite at an excellent level, while having an effect of improving thermal insulation.

[0185] The polar organic solvent can include an alcohol, and specific examples thereof can include monohydric alcohols (e.g., methanol, ethanol, isopropanol, and butanol), polyhydric alcohols (e.g., glycerol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and sorbitol), or a combination thereof, but other solvents known to those skilled in the art can also be used without limitation. When considering miscibility with water and the aerogel, the polar organic solvent can be a monohydric alcohol having 1 to 6 carbon atoms, such as methanol, ethanol, isopropanol, and butanol, and can be, for example, ethanol.

[0186] Those skilled in the art can use the polar organic solvent in an appropriate amount, considering the degree of hydrophobicity in the finally produced aerogel composite while promoting the surface modification reaction.

[0187] To prepare the pre-hydrolyzed silica precursor in preparing the silica precursor composition, the silica precursor and the organic solvent can be mixed and prepared in a weight ratio of 1:0.1-1.5, 1:0.5-1.5, or 1:0.5-1.2, but are not limited thereto.

[0188] Further, to prepare the pre-hydrolyzed silica precursor in preparing the silica precursor composition, the silica precursor and water can be mixed and prepared in a molar ratio of 1:0.1-10, 1:1-8, or 1:2-6, but are not limited thereto.

[0189] Further, when the pre-hydrolyzed TEOS is included as the silica precursor in preparing the silica precursor composition, the pre-hydrolyzed TEOS and the organic solvent can be mixed in a weight ratio of 1:2-10, 1:3-8, or 1:3-6, but are not limited thereto.

[0190] The silica precursor composition can further include an acid catalyst, and specifically, when an alkoxysilane-based compound that is not a hydrolysis product is applied as a precursor, it can further include an acid catalyst. At this time, the acid catalyst can be used without limitation as long as it is an acid catalyst allowing the pH to be 3 or less, and in some embodiments, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, oxalic acid, or acetic acid can be used. At this time, the amount of addition of the acid catalyst allows the pH of the sol to be 3 or less, and it can be added in the form of an aqueous solution in which the acid catalyst is dissolved in an aqueous solvent.

[0191] The catalyst composition can include an inorganic base (e.g., sodium hydroxide or potassium hydroxide) or an organic base (e.g., ammonium hydroxide) as an alkali catalyst. Specific examples thereof can include sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH)2), ammonia (NH3), ammonium hydroxide (NH4OH; aqueous ammonia), tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), methylamine, ethylamine, isopropylamine, mono-isopropylamine, diethylamine, diisopropylamine, dibutylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, choline, monoethanolamine, diethanolamine, 2-aminoethanol, 2-(ethylamino)ethanol, 2-(methylamino)ethanol, N-methyldiethanolamine, dimethylaminoethanol, diethylaminoethanol, nitrilotriethanol, 2-(2-aminoethoxy)ethanol, 1-amino-2-propanol, triethanolamine, monopropanolamine, dibutanolamine, pyridine, or a combination thereof, etc., but are not limited thereto.

[0192] The content of the alkali catalyst can allow the pH of the sol to be 5 to 9. If the pH of the sol exceeds the above range, it can not be easy to achieve gelation, or the gelation rate can be too low, such that processability can decrease. In addition, since the alkali can be precipitated when introduced in a solid phase, it can be preferred that the alkali is added in a solution phase diluted with an aqueous solvent or the above-described organic solvent. At this time, the dilution ratio of the alkali catalyst and the organic solvent (particularly, alcohol) can be 1:4 to 1:100 based on the volume, but is not limited thereto.

[0193] Since the catalyst composition further includes an alkoxysilane-based compound having a hydrophobic group, the hydrophobic agent and the silica wet gel can react to reinforce the structure and perform surface modification.

[0194] The type of the alkoxysilane-based compound having a hydrophobic group is not limited, as long as it is an alkylsilane compound including an alkyl group inducing hydrophobization and a silane functional group capable of reacting with the -Si-O- functional group of the wet gel, but specific examples thereof can include one or more selected from the group consisting of trimethylethoxysilane (TMES), trimethylsilanol (TMS), trimethylchlorosilane (TMCS), methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), dimethyldiethoxysilane (DMDEOS), ethyltriethoxysilane, and phenyltriethoxysilane, but are not limited thereto.

[0195] The content of the alkoxysilane-based compound having a hydrophobic group can be 3 parts by weight to 15 parts by weight, 5 parts by weight to 10 parts by weight, or 6 parts by weight to 8 parts by weight, based on 100 parts by weight of the silica sol, but is not limited thereto.

[0196] However, when the catalyst composition includes an alkoxysilane compound having a hydrophobic group, water may be included to facilitate the surface modification reaction. Based on 1 equivalent of the hydrophobic agent, the catalyst composition may contain 3 to 8 equivalents, 4 to 8 equivalents, or 5 to 6 equivalents of water.

[0197] To prepare silica sol, the silica precursor composition and the catalyst composition can be mixed in volume ratios of 1:0.01-10.0, 1:0.01-5.0, or 1:0.01-2.0, but are not limited thereto.

[0198] If necessary, additives can be further added to the silica sol. At this point, all known additives that can be added when preparing the aerogel can be applied as additives, and additives such as opacifiers and flame retardants can be used, for example.

[0199] Based on the silica content of the aerogel, the amount of additive added can be from 0.1% to 10% by weight, 0.1% to 7% by weight, 0.5% to 7% by weight, or 0.5% to 5% by weight, but is not limited thereto.

[0200] Gelation of silica sol

[0201] In this invention, after the silica sol is impregnated into the substrate, the silica sol can be gelled.

[0202] The impregnation process involves allowing the catalytic silica sol to penetrate into the pores within the substrate. This can be performed by introducing the catalytic silica sol and the substrate into a reaction vessel, or by spraying the catalytic silica sol onto the substrate moving on a conveyor belt according to a roll-to-roll process. To improve the bonding between the substrate and the silica sol, the substrate can be gently pressed downwards for thorough impregnation. Subsequently, the substrate can be pressed to a predetermined thickness using a predetermined pressure to remove excess silica sol, thereby reducing drying time.

[0203] The temperature of the silica sol in the reaction vessel can be 1°C to 40°C, 20°C to 40°C, 25°C to 40°C, 30°C to 40°C, or 35°C to 45°C. When the temperature of the silica sol in the reaction vessel meets the above ranges, it is preferable to achieve an appropriate viscosity range for the catalytic sol, and to achieve the desired viscosity range even with a relatively short retention time.

[0204] Catalytic silica sol can be impregnated into the substrate at a volume ratio of 0.1-10:1 (catalytic silica sol: substrate), 0.1-1:1, 0.3-1:1, 0.5-1:1, or 0.7-1:1, but is not limited thereto.

[0205] The silica sol impregnated into the substrate can be gelled simultaneously with the impregnation process of the silica sol, or sequentially after the impregnation process.

[0206] The substrate impregnated with the catalytic sol can be gelled on a moving element such as a conveyor belt.

[0207] "Gelation" can refer to a sol-gel reaction, and the "sol-gel reaction" can be a formation of a network structure from a silicon unit precursor material. Here, the network structure can be a planar mesh structure in which specific polygons having one or more types of atomic arrangements are linked to each other, or a structure in which specific polyhedrons share their vertices, edges, faces, etc. with each other to form a three-dimensional skeletal structure.

[0208] The gelation can be performed at an atmosphere temperature of 20°C to 40°C, 20°C to 30°C, 25°C to 40°C, 30°C to 40°C, or 35°C to 40°C, and the gelation time can be 1 minute to 120 minutes, 1 minute to 100 minutes, 1 minute to 60 minutes, 5 minutes to 60 minutes, 5 minutes to 40 minutes, 10 minutes to 40 minutes, 10 minutes to 30 minutes, or 10 minutes to 20 minutes, but is not limited thereto.

[0209] Aging of the gelled wet gel composite

[0210] If necessary, an aging step, which is to allow the wet gel composite obtained by the gelation as described above to stand at an appropriate temperature to achieve complete chemical change, can also be included. In the aging step, the network structure formed by the gelation can be formed more firmly, and thus the mechanical stability of the aerogel composite can be improved.

[0211] The aging step can be performed by allowing the gelled wet gel composite to stand at an appropriate temperature, or can be performed by adding a compound that promotes cross-linking.

[0212] Further, the aging step can be performed by adding a solution in which an alkali catalyst such as sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonium hydroxide (NH4OH), triethylamine, pyridine, etc. is diluted to a concentration of 1% to 10% in an organic solvent, in the presence of the wet gel composite. In this case, Si-O-Si bonding in the aerogel is maximally induced, so that the network structure of the silica gel can be more firmly, and thus there is an effect of promoting the maintenance of the pore structure in the later drying process. At this time, the organic solvent can be the above-described alcohol, and specifically can include ethanol.

[0213] The aging step can be performed by allowing the gelled wet gel composite to stand at a temperature of 30 to 80℃, 40 to 80℃, or 50 to 80℃ for 0.1 to 20 hours, 0.5 to 15 hours, 0.5 to 10 hours, 0.5 to 7 hours, or 1 to 5 hours to enhance the pore structure, and within this range, the production cost can be prevented from increasing by preventing the loss of solvent due to evaporation, while preventing the productivity from decreasing.

[0214] Further, the aging step can be performed by allowing the gelled wet gel composite to be subjected to a primary aging at 30 to 80℃ for 0.1 to 5 hours to enhance the pore structure in the presence of a solution in which an alkali catalyst is diluted to a concentration of 1 to 10% in an organic solvent, and then subjected to a secondary aging at 30 to 80℃ for 0.1 to 20 hours, 0.5 to 15 hours, 0.5 to 10 hours, 0.5 to 7 hours, or 1 to 5 hours.

[0215] Further, in the aging step (secondary aging if performed in two stages), a mixed solution of an alkoxysilane-based compound and an alcohol can be added to provide an additional sol precursor source as well as unreacted sol, so as to induce additional gelation in the silica gel network structure, thereby further enhancing the gel structure. At this time, the content of the alkoxysilane-based compound can be 0.5 to 9.5 parts by weight, 1.0 to 9.5 parts by weight, or 1.5 to 9.5 parts by weight, based on a total of 100 parts of the aging solution.

[0216] The alkoxysilane-based compound can include one or more selected from the group consisting of tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), methyltriethyl orthosilicate, dimethyldiethyl orthosilicate, tetrapropyl orthosilicate, tetraisopropyl orthosilicate, tetrabutyl orthosilicate, tetra-sec-butyl orthosilicate, tetra-t-butyl orthosilicate, tetrahexyl orthosilicate, tetracyclohexyl orthosilicate, tetradodecyl orthosilicate, methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), trimethylethoxysilane (TMES), trimethylsilanol (TMS), trimethylchlorosilane (TMCS), ethyltriethoxysilane (ETES), dimethyldiethoxysilane (DMDEOS), and phenyltriethoxysilane.

[0217] Further, the alcohol can be specifically a monohydric alcohol such as methanol, ethanol, isopropanol, and butanol, or a polyhydric alcohol such as glycerol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and sorbitol, preferably a monohydric alcohol having 1 to 6 carbon atoms such as methanol, ethanol, isopropanol, and butanol, and can be, for example, ethanol, but is not limited thereto.

[0218] The aging step can be performed in a separate reaction vessel after recovering the gelled wet gel composite, or can be performed within the reaction vessel in which the gelation step has been performed.

[0219] Surface modification of the aged wet gel composite

[0220] In the present application, if necessary, a surface modification step of hydrophobizing the surface of the wet gel composite or the surface of the aged wet gel composite obtained by the gelation as described above can be further included in the presence of a surface modifier.

[0221] As the surface modifier, a compound that hydrophobizes the surface of the wet gel can be applied without limitation, which can be, for example, a silane-based compound, a siloxane-based compound, a silanol-based compound, a silazane-based compound, or a combination thereof. Specific examples thereof can be a silane-based compound such as trimethylchlorosilane (TMCS), dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane (MTMS), methyltriethoxysilane (MTES), trimethylethoxysilane (TMES), vinyltrimethoxysilane, ethyltriethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, tetraethoxysilane, dimethyldichlorosilane, and 3-aminopropyltriethoxysilane; a siloxane-based compound such as polydimethylsiloxane, polydiethylsiloxane, and octamethylcyclotetrasiloxane; a silanol-based compound such as trimethylsilanol, triethylsilanol, triphenylsilanol, and t-butyldimethylsilanol; a silazane-based compound such as 1,2-diethyldisilazane, 1,1,2,2-tetramethyldisilazane, 1,1,3,3-tetramethyldisilazane, 1,1,1,2,2,2-hexamethyldisilazane (HMDS), 1,1,2,2-tetraethyldisilazane, and 1,2-diisopropyldisilazane; or a combination thereof, but is not limited thereto.

[0222] The surface modifier can be used in a solution phase in which the surface modifier is diluted in an organic solvent. Here, the organic solvent can be an alcohol (organic solvent), and at this time, the surface modifier can be diluted to 1% to 15% by volume based on the total volume of the diluted solution.

[0223] Further, the surface modifier can be added in an amount of 0.01% to 90% by volume with respect to the wet gel composite to achieve a sufficient surface modification effect, but is not limited thereto.

[0224] The surface modification step can be performed at a temperature of 50°C to 90°C or 50°C to 80°C for 1 hour to 24 hours, but is not limited thereto.

[0225] Drying step

[0226] In the present invention, a drying step can be included to obtain the aerogel composite from the surface-modified wet gel composite.

[0227] Drying is performed as a process of removing only the solvent while maintaining the pore structure of the aged gel, and can be performed, for example, by supercritical drying or atmospheric pressure drying.

[0228] The supercritical drying process is performed using supercritical carbon dioxide, and can be performed, for example, by placing the aged wet gel composite in a supercritical drying reactor, filling the reactor with liquid CO2, performing a solvent replacement process of replacing the alcohol solvent within the wet gel with CO2, then increasing the temperature at a predetermined temperature increase rate (for example, at a rate of 0.1℃ / min to 1℃ / min) to a temperature of 40℃ to 70℃, then maintaining a pressure equal to or higher than the pressure at which carbon dioxide becomes supercritical (for example, a pressure of 100 bar to 150 bar), thereby maintaining the supercritical state of carbon dioxide for a predetermined period of time, in particular, 20 minutes to 1 hour. Generally, carbon dioxide becomes supercritical at a temperature of 31℃ and a pressure of 73.8 bar. After maintaining the predetermined temperature and the predetermined pressure at which carbon dioxide becomes supercritical for 2 hours to 12 hours, more specifically, 2 hours to 6 hours, the pressure is gradually removed to complete the supercritical drying process, thereby producing an aerogel composite, but the present invention is not limited thereto.

[0229] In addition, the atmospheric pressure drying process can be performed according to a general method, for example, hot air drying or infrared drying at a temperature of 70℃ to 200℃ and atmospheric pressure (1±0.3 atm), but is not limited thereto.

[0230] In addition to the above-described methods, the present invention also includes acidifying a basic metal oxide precursor (for example, sodium silicate) in water to prepare a hydrogel. The salt byproduct can be removed from the silicate precursor by ion exchange and / or subsequent washing of the formed gel with water. The removal of water from the pores of the gel can be performed by exchange with a polar organic solvent (for example, ethanol, methanol, or acetone). Subsequently, the liquid phase in the gel is at least partially extracted using an innovative processing and extraction technique.

[0231] In addition to the above-described methods, the present invention also includes chemically transforming the wet gel state of the matrix material by converting the surface hydroxyl groups into hydrophobic trimethylsilyl ethers, thereby reducing the damaging capillary forces at the solvent / pore interface, enabling the extraction of the liquid phase from the gel material at temperatures and pressures below the solvent critical point.

[0232] In addition to the above method, in the present application, the liquid (solvent) in the gel material is frozen at a lower temperature, and then a sublimation process is performed so that the solvent can be removed from the gel material. The removal or drying of the solvent from the gel material is understood to be within the scope of the present application. This removal largely retains the gel structure, resulting in an aerogel having unique properties.

[0233] The aerogel composite provided in the present application can be used as a thermal or cold insulating material, or a non-flammable material for aircraft, ships, automobiles, electronic devices and batteries, and for plant facilities for thermal or cold insulation, such as pipes or industrial furnaces of various industrial facilities.

[0234] According to some embodiments of the present application, the thermal or cold insulating member includes the aerogel composite provided in the present application.

[0235] The thermal or cold insulating member can include the aerogel composite as described above, and a support member disposed on at least one of the upper surface or the lower surface of the aerogel composite.

[0236] The support member can be, for example, a film-like support member, a sheet-like support member, a foil-like support member, a porous support member, etc.

[0237] The film-like support member is formed by molding a polymer raw material into a thin film, and examples thereof can include organic films such as PET and polyimide, glass films, etc. (including metal deposition films).

[0238] The sheet-like support member is formed by molding an organic, inorganic or metal fiber raw material, and examples thereof can include paper, non-woven fabric (including glass mat), organic fiber fabric, glass cloth, etc.

[0239] The foil-like support member is formed by molding a metal raw material into a thin film, and examples thereof can include aluminum foil, copper foil, etc.

[0240] The porous support member has a porous structure made of an organic, inorganic or metal raw material, and examples thereof can include porous organic materials such as polyurethane foam, porous inorganic materials such as zeolite sheet, porous metal materials such as porous metal sheet, porous aluminum sheet, etc.

[0241] The thickness of the support member is not particularly limited, and can be, for example, 0.1 μm to 100 μm or 1 μm to 50 μm.

[0242] The thermal or cold insulating member can also be applied to applications such as thermal or cold insulating materials, thermal or cold insulating materials, or non-flammable materials, etc. in the fields of construction, aviation, automobiles, batteries, home appliances, semiconductors, industrial facilities, etc.

[0243] Hereinafter, the present application will be described in detail with reference to the following examples. However, the following examples are illustrative of the present application and the scope of the present application is not limited by the following examples.

[0244] Example

[0245] Example 1

[0246] Tetraethyl orthosilicate (TEOS) and water were mixed at a molar ratio of 1:4, and to this, ethanol was added at a weight ratio of 1:1 to TEOS to prepare a silica precursor solution. To promote hydrolysis of the silica precursor solution, an acid was added so that the pH of the silica precursor solution was 3 or less, and stirring was performed for 2 hours or more to prepare a hydrated TEOS solution. Ethanol was added at a weight ratio of 1:6 to the hydrated TEOS solution to prepare a silica sol. A base catalyst solution (5 wt% NaOH aqueous solution) was added at a volume ratio of 99:1 to the silica sol to prepare a catalyzed sol. After filling a dip tank with 33.3 L of the catalyzed sol, a fiber (glass fiber mat, 10 mm) as a substrate was passed therethrough to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was impregnated into the fiber mat at a volume ratio (catalyzed silica sol: fiber) of 1:1. The fiber was passed through the dip tank to allow the catalyzed sol to infiltrate therein, and the fiber was gelled for 10 minutes while moving on a conveyor belt at a predetermined rate. At this time, the ambient atmospheric temperature above the conveyor belt was maintained at 35°C. Thereafter, 109 vol% of a solution (obtained by diluting methyltriethoxysilane (MTES) to 2.9 wt% in ethanol having a water content of 10 wt%) as an aging solution was added to the gelled wet gel composite based on the volume of the wet gel composite, so as to be aged at a temperature of 75°C for 1 hour. 90 vol% of a hexamethyldisilazane (HMDS) / ethanol solution (volume ratio of 5:95) as a surface modifier was added to the aged wet gel composite based on the volume of the wet gel composite, and then surface modification was performed at a temperature of 75°C for 4 hours. Thereafter, supercritical drying was performed under conditions of CO2, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.177 g / cc.

[0247] Example 2

[0248] A tetraethyl orthosilicate (TEOS) and water were mixed at a molar ratio of 1 :4, and to this, ethanol was added at a weight ratio of 1 : 1 to the TEOS to prepare a silica precursor solution. To promote hydrolysis of the silica precursor solution, an acid was added so that the pH of the silica precursor solution was 3 or less, and stirring was performed for 2 hours or more to prepare a hydrated TEOS solution. Ethanol was added at a weight ratio of 1 :4 to the hydrated TEOS solution to prepare a silica sol. An alkali catalyst solution (5 wt% NaOH aqueous solution) was added at a volume ratio of 99: 1 to the silica sol to prepare a catalyzed sol. After filling a dip tank with 33.3 L of the catalyzed sol, a fiber (glass fiber mat, 10 mm) as a substrate was passed therethrough to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was infiltrated into the fiber mat at a volume ratio (catalyzed silica sol: fiber) of 0.7: 1. The fiber was passed through the dip tank to allow the catalyzed sol to infiltrate therein, and the fiber was moved on a conveyor belt at a predetermined rate while being gelled for 10 minutes. At this time, the ambient atmospheric temperature above the conveyor belt was maintained at 40°C. Thereafter, to the gelled wet gel composite, 109 vol% of a solution (which was obtained by diluting methyltriethoxysilane (MTES) to 2.9 wt% in ethanol having a water content of 10 wt%) as an aging solution was added based on the volume of the wet gel composite, so as to be aged at a temperature of 75°C for 1 hour. To the aged wet gel composite, 90 vol% of a hexamethyldisilazane (HMDS) / ethanol solution (volume ratio of 5:95) as a surface modifier was added based on the volume of the wet gel composite, and then surface modification was performed at a temperature of 75°C for 4 hours. Thereafter, supercritical drying was performed under conditions of C02, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.187 g / cc.

[0249] Example 3

[0250] Methyltriethoxysilane (MTES) and TEOS were mixed at a molar ratio of 97:3 to prepare a silica precursor composition. The silica precursor composition and water were mixed at a molar ratio of 1:10, and to this, ethanol was added at a weight ratio of 1:2 to the silica precursor composition to prepare a silica sol. In order to promote hydrolysis, hydrochloric acid was added so that the pH of the silica sol was 3 or less. An alkali catalyst solution (10 wt% NaOH aqueous solution) was added at a volume ratio of 99:1 to the silica sol to prepare a catalyzed silica sol. After filling a dip tank with 33.3 L of the catalyzed sol, a fiber (glass fiber mat, 5 mm) as a substrate was passed therethrough to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was infiltrated into the fiber mat at a volume ratio (catalyzed silica sol: fiber) of 0.5:1. The fiber was passed through the dip tank to allow the catalyzed sol to infiltrate therein, and the fiber was moved on a conveyor belt at a predetermined rate while being gelled for 10 minutes. At this time, the ambient atmospheric temperature above the conveyor belt was maintained at 35°C. Thereafter, to the gelled wet gel composite, 109 vol% of a solution obtained by diluting ammonia water in ethanol to 2.4 wt% as an aging solution was added based on the volume of the wet gel composite so as to be aged at a temperature of 75°C for 1 hour. To the aged wet gel composite, 90 vol% of a hexamethyldisilazane (HMDS) / ethanol solution (volume ratio of 5:95) as a surface modifier was added based on the volume of the wet gel composite, and then surface modification was performed at a temperature of 75°C for 4 hours. Thereafter, supercritical drying was performed under conditions of CO2, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.170 g / cc.

[0251] Example 4

[0252] Methyltriethoxysilane (MTES) and TEOS were mixed at a molar ratio of 97:3 to prepare a silica precursor composition. The silica precursor composition and water were mixed at a molar ratio of 1:10, and to this, ethanol was added at a weight ratio of 1:2 to the silica precursor composition to prepare a silica sol. In order to promote hydrolysis, hydrochloric acid was added so that the pH of the silica sol was 3 or less. An alkali catalyst solution (10 wt% NaOH aqueous solution) was added at a volume ratio of 99:1 to the silica sol to prepare a catalyzed silica sol. After filling a dip tank with 33.3 L of the catalyzed sol, a fiber (glass fiber mat, 5 mm) as a substrate was passed therethrough to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was infiltrated into the fiber mat at a volume ratio (catalyzed silica sol: fiber) of 0.7:1. The fiber was passed through the dip tank to allow the catalyzed sol to infiltrate therein, and the fiber was moved on a conveyor belt at a predetermined rate while being gelled for 10 minutes. At this time, the ambient atmospheric temperature above the conveyor belt was maintained at 40°C. Thereafter, to the gelled wet gel composite, 109 vol% of a solution obtained by diluting ammonia water in ethanol to 2.4 wt% as an aging solution was added based on the volume of the wet gel composite so as to be aged at a temperature of 75°C for 1 hour. To the aged wet gel composite, 90 vol% of a hexamethyldisilazane (HMDS) / ethanol solution (volume ratio of 5:95) as a surface modifier was added based on the volume of the wet gel composite, and then surface modification was performed at a temperature of 75°C for 4 hours. Thereafter, supercritical drying was performed under conditions of CO2, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.190 g / cc.

[0253] Example 5

[0254] Methyltriethoxysilane (MTES) and TEOS were mixed at a molar ratio of 97:3 to prepare a silica precursor composition. The silica precursor composition and water were mixed at a molar ratio of 1:10, and to this, ethanol was added at a weight ratio of 1:2 to the silica precursor composition to prepare a silica sol. In order to promote hydrolysis, hydrochloric acid was added so that the pH of the silica sol was 3 or less. An alkali catalyst solution (10 wt% NaOH aqueous solution) was added at a volume ratio of 99:1 to the silica sol to prepare a catalyzed silica sol. After filling a dip tank with 33.3 L of the catalyzed sol, a fiber (glass fiber mat, 5 mm) as a substrate was passed therethrough to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was infiltrated into the fiber mat at a volume ratio (catalyzed silica sol: fiber) of 0.7:1. The fiber was passed through the dip tank to allow the catalyzed sol to infiltrate therein, and the fiber was gelled for 10 minutes while moving on a conveyor belt at a predetermined rate. At this time, the ambient atmospheric temperature above the conveyor belt was maintained at 40°C. Thereafter, to the gelled wet gel composite, 109 vol% of a solution (obtained by diluting trimethylethoxysilane (TMES) in ethanol to 2.4 wt%) as an aging solution was added based on the volume of the wet gel composite, so as to be aged at a temperature of 75°C for 1 hour. To the aged wet gel composite, 90 vol% of a hexamethyldisilazane (HMDS) / ethanol solution (volume ratio of 5:95) as a surface modifier was added based on the volume of the wet gel composite, and then surface modification was performed at a temperature of 75°C for 4 hours. Thereafter, supercritical drying was performed under conditions of C02, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.211 g / cc.

[0255] Example 6

[0256] Methyltriethoxysilane (MTES) and TEOS were mixed in a molar ratio of 97:3 to prepare a silica precursor composition. The silica precursor composition and water were mixed in a molar ratio of 1:10, and to this, ethanol was added in a weight ratio of 1:2 to the silica precursor composition to prepare a silica sol. In order to promote hydrolysis, hydrochloric acid was added so that the pH of the silica sol was 3 or less. An alkali catalyst solution (10 wt% NaOH aqueous solution) was added in a volume ratio of 99:1 to the silica sol to prepare a catalyzed silica sol. After filling a dip tank with 33.3 L of the catalyzed sol, a fiber (glass fiber mat, 5 mm) as a substrate was passed therethrough to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was infiltrated into the fiber mat in a volume ratio (catalyzed silica sol: fiber) of 1:1. The fiber was passed through the dip tank to allow the catalyzed sol to infiltrate therein, and the fiber was moved on a conveyor belt at a predetermined rate while being gelled for 10 minutes. At this time, the ambient atmospheric temperature above the conveyor belt was maintained at 35°C. Thereafter, 109 vol% of a solution obtained by diluting trimethylethoxysilane (TMES) in ethanol to 2.4 wt% as an aging solution was added to the gelled wet gel composite based on the volume of the wet gel composite so as to be aged at a temperature of 75°C for 1 hour. 90 vol% of a hexamethyldisilazane (HMDS) / ethanol solution (volume ratio of 5:95) as a surface modifier was added to the aged wet gel composite based on the volume of the wet gel composite, and then surface modification was performed at a temperature of 75°C for 4 hours. Thereafter, supercritical drying was performed under the conditions of CO2, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.206 g / cc.

[0257] Example 7

[0258] A tetraethyl orthosilicate (TEOS) and water were mixed at a molar ratio of 1:4, and to this, ethanol and the TEOS were added at a weight ratio of 1:1 to prepare a silica precursor solution. To promote hydrolysis of the silica precursor solution, an acid was added so that the pH of the silica precursor solution was 3 or less, and stirring was performed for 2 hours or more to prepare a hydrated TEOS solution. Ethanol and the hydrated TEOS solution were added at a weight ratio of 1:4 to prepare a silica sol. An alkali catalyst solution (5 wt% NaOH aqueous solution) and the silica sol were added at a volume ratio of 99:1 to prepare a catalyzed silica sol. After filling a dip tank with 33.3 L of the catalyzed sol, a fiber (glass fiber mat, 3 mm) as a substrate was passed therethrough to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was infiltrated into the fiber mat at a volume ratio (catalyzed silica sol:fiber) of 0.7:1. The fiber was passed through the dip tank to allow the catalyzed sol to infiltrate therein, and the fiber was moved on a conveyor belt at a predetermined rate while being gelled for 10 minutes. At this time, the ambient atmospheric temperature above the conveyor belt was maintained at 35°C. After the gelling was completed, stabilization was performed for 10 minutes at room temperature (25°C), and then a first aging was performed in an oven at 70°C for 50 minutes. Thereafter, a mixture of ethanol and ammonia water (volume ratio of 98:2) was prepared and added to the gelled wet gel composite in an amount of 1.6 times the volume of the silica sol, and then a second aging was performed in an oven at 70°C for 1 hour. To the aged wet gel composite, a solution (obtained by diluting trimethylethoxysilane (TMES) in ethanol, 2 vol%) as a surface modifier was added at 90 vol% based on the volume of the wet gel composite, and then surface modification was performed at a temperature of 75°C for 2 hours. Thereafter, supercritical drying was performed under conditions of CO2, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.189 g / cc.

[0259] Example 8

[0260] A tetraethyl orthosilicate (TEOS) and water were mixed at a molar ratio of 1 :4, and to this, ethanol was added at a weight ratio of 1 : 1 to the TEOS to prepare a silica precursor solution. To promote hydrolysis of the silica precursor solution, an acid was added so that the pH of the silica precursor solution was 3 or less, and stirring was performed for 2 hours or more to prepare a hydrated TEOS solution. Ethanol was added at a weight ratio of 1 :6 to the hydrated TEOS solution to prepare a silica sol. An alkali catalyst solution (5 wt% NaOH aqueous solution) was added at a volume ratio of 99: 1 to the silica sol to prepare a catalyzed silica sol. After filling a dip tank with 33.3 L of the catalyzed sol, a fiber (glass fiber mat, 3 mm) as a substrate was passed therethrough to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was infiltrated into the fiber mat at a volume ratio (catalyzed silica sol: fiber) of 0.7: 1. The fiber was passed through the dip tank to allow the catalyzed sol to infiltrate therein, and the fiber was moved on a conveyor belt at a predetermined rate while being gelled for 10 minutes. At this time, the ambient atmospheric temperature above the conveyor belt was maintained at 25°C. After the gelling was completed, stabilization was performed for 10 minutes at room temperature (25°C), and then a first aging was performed for 50 minutes in an oven at 70°C. Thereafter, a solution (obtained by diluting methyltriethoxysilane (MTES) to 2.9 wt% in ethanol having a water content of 10 wt%) was added to the gelled wet gel composite at 109 vol% based on the volume of the wet gel composite so as to perform a second aging for 1 hour at a temperature of 75°C. A solution (2 vol%, obtained by diluting trimethylethoxysilane (TMES) in ethanol) was added to the aged wet gel composite as a surface modifier at 90 vol% based on the volume of the wet gel composite, and then surface modification was performed for 2 hours at a temperature of 75°C. Thereafter, supercritical drying was performed under conditions of CO2, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.192 g / cc.

[0261] Example 9

[0262] A tetraethyl orthosilicate (TEOS) and water were mixed at a molar ratio of 1 :4, and to this, ethanol was added at a weight ratio of 1 : 1 to the TEOS to prepare a silica precursor solution. To promote hydrolysis of the silica precursor solution, an acid was added so that the pH of the silica precursor solution was 3 or less, and stirring was performed for 2 hours or more to prepare a hydrated TEOS solution. Ethanol was added at a weight ratio of 1 :6 to the hydrated TEOS solution to prepare a silica sol. An alkali catalyst solution (5 wt% NaOH aqueous solution) was added at a volume ratio of 99: 1 to the silica sol to prepare a catalyzed silica sol. After filling a dip tank with 33.3 L of the catalyzed sol, a fiber (glass fiber mat, 5 mm) as a substrate was passed therethrough to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was infiltrated into the fiber mat at a volume ratio (catalyzed silica sol: fiber) of 0.7: 1. The fiber was passed through the dip tank to allow the catalyzed sol to infiltrate therein, and the fiber was moved on a conveyor belt at a predetermined rate while being gelled for 10 minutes. At this time, the ambient atmospheric temperature above the conveyor belt was maintained at 35°C. After the gelling was completed, stabilization was performed for 10 minutes at room temperature (25°C), and then a first aging was performed in an oven at 70°C for 50 minutes. Thereafter, to the gelled wet gel composite, 109 vol% of a solution (which was obtained by diluting methyltriethoxysilane (MTES) to 2.9 wt% in ethanol having a water content of 10 wt%) was added based on the volume of the wet gel composite, so as to perform a second aging at a temperature of 75°C for 1 hour. Thereafter, supercritical drying was performed under conditions of CO2, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.204 g / cc.

[0263] Comparative Example 1

[0264] A pre-hydrolyzed TEOS (silica content: 20 wt%, HTEOS), ethanol and distilled water were added in a weight ratio of 1 :2:0.22, respectively, and then mixed to prepare a silica precursor composition. Ethanol, NaOH (5 wt% aqueous solution) and trimethylethoxysilane (TMES) were added in a weight ratio of 1 :0.3:1, respectively, and then mixed to prepare a catalyst composition. In a reactor, the silica precursor composition and the catalyst composition prepared above were mixed in a volume ratio of 9:1 to prepare a catalyzed silica sol. A fiber (glass fiber mat, 10 mm) as a substrate was passed through to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was impregnated in a volume ratio of 1 :1 (catalyzed silica sol: glass fiber mat) with respect to the volume of the glass fiber mat, and then gelation was performed thereon after 10 minutes to prepare a wet gel composite. The fiber was passed through an impregnation tank to infiltrate the catalyzed sol, and the fiber was left to stand at room temperature for 24 hours to perform gelation, aging and surface modification. Thereafter, supercritical drying was performed under conditions of CO2, 150 bar and 70°C to produce an aerogel composite having a density of about 0.206 g / cc.

[0265] Comparative Example 2

[0266] A tetraethyl orthosilicate (TEOS) and water were mixed at a molar ratio of 1:4, and to this, ethanol was added at a weight ratio of 1:1 to the TEOS to prepare a silica precursor solution. To promote hydrolysis of the silica precursor solution, an acid was added so that the pH of the silica precursor solution was 3 or less, and stirring was performed for 2 hours or more to prepare a hydrated TEOS solution. Ethanol was added to the hydrated TEOS solution at a weight ratio of 1:4 to prepare a silica sol. An alkali catalyst solution (5 wt% NaOH aqueous solution) was added to the silica sol at a volume ratio of 99:1 to prepare a catalyzed sol. A fiber (glass fiber mat, 10 mm) as a substrate was passed through to infiltrate the catalyzed sol into the fiber, wherein the catalyzed silica sol was impregnated at a volume ratio of 0.3:1 (catalyzed silica sol: glass fiber mat) with respect to the volume of the glass fiber mat, and then gelation was performed thereon after 10 minutes to prepare a wet gel composite. The fiber was passed through an impregnation tank to infiltrate the catalyzed sol therein, and the fiber was gelled for 10 minutes while moving at a predetermined rate on a conveyer belt. At this time, the ambient atmospheric temperature above the conveyer belt was maintained at 35°C. Thereafter, the gelled wet gel composite was aged in a chamber at 70°C for 24 hours. Thereafter, to the aged wet gel composite, a hexamethyldisilazane (HMDS) / ethanol solution (volume ratio of 5:95) as a surface modifier was added at 90 vol%, and then surface modification was performed at a temperature of 75°C for 4 hours. Thereafter, supercritical drying was performed under conditions of CO2, 150 bar, and 70°C to produce an aerogel composite having a density of about 0.142 g / cc.

[0267] Comparative Example 3

[0268] Tetraethyl orthosilicate (TEOS) and water were mixed at a molar ratio of 1:4, and ethanol and TEOS were added thereto at a weight ratio of 1:1 to prepare a silica precursor solution. To promote hydrolysis of the silica precursor solution, an acid was added so that the pH of the silica precursor solution was 3 or less, and stirring was performed for 2 hours or more to prepare a hydrated TEOS solution. Ethanol and the hydrated TEOS solution were added at a weight ratio of 1:4 to prepare a silica sol. An alkali catalyst solution (5 wt% NaOH aqueous solution) and the silica sol were added at a volume ratio of 99:1 to prepare a catalyzed sol. A fiber (glass fiber mat, 3 mm) as a substrate was passed through to infiltrate the catalyzed sol into the fiber, in which the catalyzed silica sol was impregnated at a volume ratio (catalyzed silica sol: glass fiber mat) of 0.5:1 with respect to the volume of the glass fiber mat, and then gelation was performed thereon after 10 minutes, to prepare a wet gel composite. The fiber was passed through an impregnation tank to infiltrate the catalyzed sol therein, and the fiber was gelated for 10 minutes while moving at a predetermined rate on a conveyor belt. After the gelation was completed, stabilization was performed for 10 minutes at room temperature (25℃), and then primary aging was performed in an oven at 70℃ for 50 minutes. Thereafter, a mixture of ethanol and ammonia water (volume ratio of 98:2) was prepared and added to the gelated wet gel composite in an amount of 1.6 times the volume of the silica sol, and then secondary aging was performed in an oven at 70℃ for 1 hour. Thereafter, supercritical drying was performed under conditions of CO2, 150 bar, and 70℃ to produce an aerogel composite having a density of about 0.168 g / cc.

[0269] Experimental Example 1. Measurement of density and pore size specific distribution

[0270] 1. Density

[0271] For the silica aerogel composite produced in each of the examples and comparative examples, five samples each having a size of 10 cm x 10 cm were prepared, and then the weight of each sample was measured, and the thickness of each sample was measured using an HFM436 device of NETZSCH GmbH. The density was calculated using the measured weight, thickness, and size, and the average density of the 5 samples was determined as the final density, the results of which are shown in Table 1 below.

[0272] 2. Volume ratio (%) of effective pores having a pore diameter of 30 nm or less

[0273] For each of the silica aerogel composites prepared in the respective examples and comparative examples, the specific surface area, pore volume, and pore diameter were measured by analyzing the amount of nitrogen adsorption and desorption according to partial pressure (0.11 < p / p0 < 1) using an ASAP 2010 apparatus (Micromeritics Inc.). From the measured pore volume, the volume ratio of pores (effective pores) having a diameter in the range of 30 nm or less was calculated, and the results are shown in Table 1 below.

[0274] [Table 1]

[0275]

[0276] Experimental Example 2. Measurement of recovery rate after compression and heat transfer coefficient of aerogel composite

[0277] 1. Compression recovery rate

[0278] Samples each having a size of 20 cm x 20 cm were prepared using the aerogel composites obtained in the examples and comparative examples. Here, if the width or length dimension of the produced aerogel composite is less than 20 cm, two or more samples can be rearranged side by side so that the size of the sample becomes 20 cm x 20 cm, and then the sample can be measured. Each of the prepared samples was then pressed for 10 minutes under the respective pressure conditions using a QM900A-15T press apparatus of QMESYS Co., Ltd. Before pressing and 1 hour after completion of pressing, the thickness of each aerogel composite was measured using an HFM436 apparatus of Netzsch Co., Ltd., and the compression recovery rate was calculated according to Equation 1 below, and the results are shown in Table 2 below. However, the pressure values shown in Table 2 below are pressure values applied to each unit area of the sample, and refer to values obtained by multiplying the barrel area of the press apparatus by the set pressure value and dividing the product by the area of the sample, as shown in Equation 2 below. The barrel radius of the QM900A-15T press apparatus used in this experiment was 6.25 cm, and the barrel size was 12.5 cm.

[0279] [Equation 1]

[0280] Compression recovery rate (%) = {(cross-sectional thickness of the aerogel composite after compression) / (cross-sectional thickness of the aerogel composite before compression)} x 100

[0281] [Equation 2]

[0282] Actual pressure value = (radius (cm) of the inner diameter of the press apparatus barrel x radius (cm) of the inner diameter of the press apparatus barrel x 3.14 x set pressure value) / (area (cm 2 ))

[0283] 2. Evaluation of change in heat transfer coefficient after compression (1)

[0284] The experiment was performed in the same manner as in the above 1, and the thermal conductivity of each aerogel composite was measured using the HFM436 device of Netzsch Co., Ltd. before compression and 1 hour after completion of compression, and then the heat transfer coefficient was calculated, and the increase rate of the heat transfer coefficient compared to before compression was evaluated, and the results are shown in Table 3 below.

[0285] Further, in order to confirm the degree of change in the heat transfer coefficient after compression, the average value (b) of the heat transfer coefficient measured after compression at a pressure of 9 to 30 bar was calculated, and as shown in the following Equation 3, the difference between the heat transfer coefficient (a) measured after compression at a pressure of 9 to 30 bar and the average value (b) was calculated, and the value A obtained by dividing the difference by the average value (b) of the heat transfer coefficient was calculated, and the results are shown in Table 4.

[0286] [Equation 3]

[0287] (Heat transfer coefficient after compression (a) - average value (b) of heat transfer coefficient after compression) = (average value (b) of heat transfer coefficient after compression) x A

[0288] Each of the result values shown in Tables 2 to 4 is rounded off from three decimal places and expressed to two decimal places.

[0289] [Table 2]

[0290]

[0291]

[0292] [Table 3]

[0293]

[0294]

[0295]

[0296] [Table 4]

[0297]

[0298]

[0299] 3. Evaluation of change in heat transfer coefficient after compression (2)

[0300] Further, to examine the change in the heat transfer coefficient after compression in the range of 3 bar to 24 bar, the average value (b) of the heat transfer coefficient measured after compression at the pressures of 3 bar, 9 bar, and 24 bar was calculated. As shown in Equation 3, the difference between the heat transfer coefficient (a) measured after compression at the pressure of 3 bar, 9 bar, or 24 bar and the average value (b) was calculated, and the value A obtained by dividing the difference by the average value (b) of the heat transfer coefficient was calculated, the results of which are shown in Table 5 below. After rounding to the third decimal place, each of the result values shown in Table 5 was rounded to the second decimal place.

[0301] [Table 5]

[0302]

[0303] 4. Evaluation of the change in the heat transfer coefficient before and after compression

[0304] Further, to examine the change in the heat transfer coefficient before and after compression, the average value (d) of the heat transfer coefficient measured after compression of the aerogel composite at the pressures of 0 bar (uncompressed), 3 bar, 9 bar, and 24 bar was calculated. As shown in Equation 4 below, the difference between the heat transfer coefficient (c) measured before and after compression at the respective pressures of 0 bar, 3 bar, 9 bar, and 24 bar and the average value (d) of those heat transfer coefficients was calculated, and the value D obtained by dividing the difference by the average value (d) of the heat transfer coefficient, the results of which are shown in Table 6 below. After rounding to the third decimal place, each of the result values shown in Table 6 was rounded to the second decimal place.

[0305] [Equation 4]

[0306] (Heat transfer coefficient before and after compression (c) - Average value of heat transfer coefficient before and after compression (d)) = (Average value of heat transfer coefficient before and after compression (d)) × D

[0307] [Table 6]

[0308]

[0309]

[0310] As shown in Tables 2 to 6, it was confirmed that the aerogel composites of Examples 1 to 9 prepared according to the present application had a higher compression recovery rate than the aerogel composites of Comparative Examples 1 to 3. Further, it was confirmed that the aerogel composites of Examples 1 to 9 according to the present application exhibited a smaller increase in the heat transfer coefficient after compression than before compression, and the change in the heat transfer coefficient was small even when compressed at various pressure values at low or high pressures, and the thermal insulation performance was maintained at an excellent level.

[0311] It is confirmed from the results that the aerogel composite of the present application has excellent elasticity, flexibility and strength of pores, and thus has excellent resilience even after high-pressure compression, and thus it has been confirmed that the sharp deterioration of the thermal insulation performance caused by the destruction of the pores, particularly the destruction of the pores having a size of 30 nm or less, is prevented, and the thermal insulation performance is maintained excellent even after compression.

[0312] As described above, specific portions of the present application have been described in detail; however, it is obvious that such detailed description is provided to the preferred embodiments for the person skilled in the art only for the purpose of illustration, and the scope of the present application is not limited thereto. Therefore, the substantial scope of the present application should be defined by the appended claims and equivalents thereof.

[0313] Industrial applicability

[0314] The present application relates to an aerogel composite which can maintain excellent thermal insulation performance without a significant decrease in thermal insulation capacity even when compressed under external pressure, and to the use of the aerogel composite as a thermal insulation material. The thermal insulation material can be applied to a battery, an electronic device, an automobile, an industrial device, or a structure.

Claims

1. An aerogel composite comprising a fibrous substrate and an aerogel comprising one or more pores, wherein, When the aerogel composite is compressed by applying a pressure of 24 bar, 30 bar and 33 bar in the lateral direction with respect to the aerogel composite, respectively, the heat transfer coefficient after compression is not more than 3 times the heat transfer coefficient before compression.

2. The aerogel composite of claim 1, wherein, When the aerogel composite is compressed by applying a pressure of 24 bar, 30 bar and 33 bar in the lateral direction with respect to the aerogel composite, respectively, the heat transfer coefficient after compression is more than 1 times the heat transfer coefficient before compression, and not more than 3 times the heat transfer coefficient before compression.

3. The aerogel composite of claim 1, wherein, When a pressure of 3 bar is applied to the aerogel composite in the lateral direction with respect to the aerogel composite, the heat transfer coefficient after compression is not more than 1.45 times the heat transfer coefficient before compression.

4. The aerogel composite of claim 3, wherein, When a pressure of 3 bar is applied to the aerogel composite in the lateral direction with respect to the aerogel composite, the heat transfer coefficient after compression is equal to or not more than 1.45 times the heat transfer coefficient before compression.

5. The aerogel composite of claim 1, wherein, When a pressure of 9 bar is applied to the aerogel composite in the lateral direction with respect to the aerogel composite, the heat transfer coefficient after compression is not more than 1.85 times the heat transfer coefficient before compression.

6. The aerogel composite of claim 1, wherein, When a pressure of 9 bar is applied to the aerogel composite in the lateral direction with respect to the aerogel composite, the heat transfer coefficient after compression is equal to or not more than 1.85 times the heat transfer coefficient before compression.

7. The aerogel composite of claim 1, wherein, When a pressure of 15 bar is applied to the aerogel composite in the lateral direction with respect to the aerogel composite, the heat transfer coefficient after compression is not more than 2.35 times the heat transfer coefficient before compression.

8. The aerogel composite of claim 7, wherein, When a pressure of 15 bar is applied to the aerogel composite in the lateral direction with respect to the aerogel composite, the heat transfer coefficient after compression is equal to or not more than 2.35 times the heat transfer coefficient before compression.

9. The aerogel composite of claim 1, wherein, When a pressure of 9 bar, 15 bar, 24 bar, 30 bar and 33 bar is applied to the aerogel composite in the lateral direction with respect to the aerogel composite, respectively, the compression recovery rate represented by the following Formula 1 is 60% or more: [Formula 1] Compression recovery rate (%) = {(cross-sectional thickness of the aerogel composite after compression) / (cross-sectional thickness of the aerogel composite before compression)} x 100.

10. The aerogel composite of claim 9, wherein, When a pressure of 9 bar, 15 bar, 24 bar, 30 bar and 33 bar is applied to the aerogel composite in the lateral direction with respect to the aerogel composite, respectively, the compression recovery rate represented by Formula 1 is 60% to 99%.

11. The aerogel composite of claim 1, wherein, The heat transfer coefficient obtained after the aerogel composite is compressed at a pressure of 9 bar, 15 bar, 24 bar and 30 bar, respectively, satisfies the following Formula 3: [Formula 3] (heat transfer coefficient after compression (a) - average value of heat transfer coefficient after compression (b)) = (average value of heat transfer coefficient after compression (b)) x A wherein the heat transfer coefficient after compression (a) is a heat transfer coefficient obtained after compression at a pressure of any one of 9 bar, 15 bar, 24 bar and 30 bar in the lateral direction with respect to the aerogel composite; The average value (b) of the heat transfer coefficients after compression is an average value of the heat transfer coefficients obtained after compression at pressures of 9 bar, 15 bar, 24 bar, and 30 bar, respectively, in the lateral direction with respect to the aerogel composite; and A is a rational number of -0.15 to +0.

15.

12. The aerogel composite of claim 1, wherein, The heat transfer coefficient after compression is not more than 1.8 times the heat transfer coefficient before compression when the aerogel composite is compressed by applying pressures of 3 bar, 9 bar, and 24 bar, respectively, in the lateral direction with respect to the aerogel composite, where the heat transfer coefficients before and after compression for the aerogel composite satisfy the following formula 4: [Formula 4] (Heat transfer coefficient before and after compression (c) - Average value of heat transfer coefficients before and after compression (d)) = (Average value of heat transfer coefficients before and after compression (d)) x D where the heat transfer coefficient before and after compression (c) is a heat transfer coefficient obtained after compression at a pressure of 0 bar, 3 bar, 9 bar, or 24 bar in the lateral direction with respect to the aerogel composite; The average value of the heat transfer coefficients before and after compression (d) is an average value of the heat transfer coefficients obtained after compression at pressures of 0 bar, 3 bar, 9 bar, and 24 bar, respectively, in the lateral direction with respect to the aerogel composite; and D is a rational number of -0.25 to +0.

25.

13. The aerogel composite of claim 1, wherein, For the aerogel composite, the rate of change (B) of the heat transfer coefficient after compression per unit of applied pressure represented by the following formula 5 is a rational number of -0.10 to +0.10: [Formula 5] B = (Heat transfer coefficient after compression at pressure x - Heat transfer coefficient after compression at pressure y) / (x - y) where in the above formula 5, x and y are independently pressure values (unit: bar) of any one of 9 bar, 15 bar, or 24 bar, and are pressure values different from each other.

14. The aerogel composite of claim 1, wherein, The aerogel contains pores having a pore diameter of 30 nm or less, which account for 30% to 45% of the pore volume of the skeletal structure of the aerogel.

15. The aerogel composite of claim 13, wherein, The aerogel contains pores having a pore diameter of 0.1 nm to 30 nm, which account for 30% to 45% of the pore volume of the skeletal structure of the aerogel.

16. The aerogel composite of claim 1, wherein, The aerogel composite has a density of 0.05 g / cm 3 to 0.50 g / cm 3 .

17. The aerogel composite of claim 1, wherein, The aerogel is a silica aerogel.

18. The aerogel composite of claim 1, wherein, The heat transfer coefficient after compression is measured 1 hour after the completion of the compression.

19. A thermal insulation member comprising the aerogel composite according to any one of claims 1 to 18.

20. The insulating means of claim 19, wherein, The thermal insulation member further comprises a support member placed on at least one of the upper surface or the lower surface of the aerogel composite. The heat transfer coefficient after compression is measured 1 hour after the completion of the compression.

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