Aerogel powder composition

Abstract

To provide an aerogel powder composition including aerogel powders excellent in flexibility and hardly-destructive property against compressive force.SOLUTION: An aerogel powder included in the aerogel powder composition in this invention comprises an aerogel which is a hydrolysis condensate of silane compound. The silane compound satisfies 0≤Qx≤70, 30≤Tx≤100 and 0≤Dx<30 (here, Qx+Tx+Dx=100) when defining the mass percentages of 4-, 3- and 2-functional silane compounds as Qx, Tx and Dx, respectively. The fracture rate of the aerogel powder prescribed by fracture rate (%)=[fracture amount (g) / mass (g) of aerogel powder before fracture]×100 is 10% or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an aerogel powder composition containing an aerogel powder that is excellent in flexibility and fracture resistance against compressive force.

Background Art

[0002] Conventionally, a gel dry body having a siloxane bond called an aerogel has been known. Specifically, a sol is formed by hydrolyzing a monomer solution of a silane compound (solvent: water and / or an organic solvent), and after forming a gel (condensation compound) by subjecting the sol to a cross-linking reaction, the gel is dried to obtain an aerogel (gel dry body) having a large number of pores (Patent Document 1).

[0003] Since this aerogel has excellent heat insulation properties, optical properties, and electrical properties, it has been considered for use in various fields. Among them, aerogel powder is obtained by forming an aerogel into a powder form, and an expansion of the usage fields is expected from its form (Patent Documents 2 and 3).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, aerogel powder is very brittle, and when it is processed into a suitable form for use, for example, when it is packed at a high filling rate or added to a paint or the like and kneaded, it is further crushed finer than the original powder particle size, and there is a problem that the expected level of fracture resistance (the property of being difficult to break) cannot be obtained.

[0006] In addition, in the case of aerogel powder that has been surface-treated, when it is crushed finely, untreated portions are exposed, and there is also a problem that the effect of the surface treatment is impaired. These problems are presumed to be due to the insufficient flexibility, particularly flexibility (the property of being elastic and easily deformed with respect to compressive force), of the aerogel powder.

[0007] An object of the present invention is to provide an aerogel powder composition containing an aerogel powder that is excellent in flexibility and fracture resistance with respect to compressive force.

Means for Solving the Problems

[0008] The object of the present invention has been achieved as follows.

[0009] 1. An aerogel powder composition containing at least an aerogel powder, wherein the aerogel powder is composed of an aerogel that is a hydrolysis condensate of a silane compound, and when the mass percentages of a tetrafunctional silane compound, a trifunctional silane compound, and a bifunctional silane compound in the silane compound are Qx, Tx, and Dx, respectively, 0 ≦ Qx ≦ 70, 30 ≦ Tx ≦ 100, 0 ≦ Dx < 30 (where Qx + Tx + Dx = 100), and the aerogel powder has a fracture rate defined by the following formula (1) of 10% or less: an aerogel powder composition. Fracture rate (%) = (amount of fracture (g) / mass of aerogel powder before fracture (g)) × 100 ··· (1) Here, the "amount of fracture" means that 3 ml of aerogel powder adjusted to a particle size range of 250 μm to 1000 μm with a sieve is compressed by a universal testing machine with a cross-sectional area of 1.34 cm 2 , a maximum load of 500 N, and a compressive stress of 371.2 N / m2 It means the total mass (g) of the broken aerogel powder that has been compressed under the following conditions and, after compression, passed through a sieve with an aperture of 250 μm. 2. The aerogel powder of the aerogel powder composition according to item 1 above, wherein the deformation rate defined by the following formula (2) is 15% or more. Deformation rate (%) = {Change in deformation amount (mm) / Filling height of aerogel before deformation (mm)} × 100 ··· (2) Here, the "change in deformation amount" means the change in filling height (mm) when the aerogel powder is filled to a height of 16 mm in a cylindrical cylinder container having a bottom area of 1.34 cm 2 and compressed with a piston at 10 N. The filling height of the aerogel before deformation is 16 mm. 3. The aerogel powder composition according to item 1 above, wherein the silane compound satisfies 0 < Qx ≤ 50, 40 ≤ Tx < 100, 0 ≤ Dx < 30 (where Qx + Tx + Dx = 100), and the destruction rate of the aerogel powder is 6% or less. 4. The aerogel powder composition according to item 3 above, wherein the deformation rate defined by the following formula (2) of the aerogel powder is 20% or more. Deformation rate (%) = {Change in deformation amount (mm) / Filling height of aerogel before deformation (mm)} × 100 ··· (2) Here, the "change in deformation amount" means the change in filling height (mm) when the aerogel powder is filled to a height of 16 mm in a cylindrical cylinder container having a bottom area of 1.34 cm 2 and compressed with a piston at 10 N. The filling height of the aerogel before deformation is 16 mm. 5. The aerogel powder composition according to any one of items 1 to 4 above, wherein the aerogel powder is composed of an aerogel dried by an atmospheric pressure drying method. 6. The aerogel powder composition according to any one of items 1 to 5 above, wherein the aerogel powder composition is a mixture of the aerogel powder and other powder particles. 7. The aerogel powder composition according to any one of 1 to 5 above, wherein the aerogel powder composition is an aerogel powder dispersion in which the aerogel powder is dispersed in a liquid dispersion medium with the aerogel powder as the dispersed phase.

Advantages of the Invention

[0010] According to the present invention, it is possible to provide an aerogel powder composition excellent in flexibility and resistance to destruction against compressive force and the aerogel powder thereof.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described. (1) Aerogel powder composition (1-1) Aerogel The aerogel powder composition of the present invention is an aerogel powder composition containing at least an aerogel powder, and the aerogel powder is composed of an aerogel that is a hydrolysis condensate of a silane compound. When the mass percentages of the tetrafunctional silane compound, trifunctional silane compound, and bifunctional silane compound in the silane compound are Qx, Tx, and Dx, respectively, 0 ≦ Qx ≦ 70, 30 ≦ Tx ≦ 100, 0 ≦ Dx < 30 (however, Qx + Tx + Dx = 100), and the aerogel powder is an aerogel powder composition characterized in that the destruction rate determined by the following formula (1) is 10% or less. Destruction rate (%) = (Amount of destruction (g) / Mass of aerogel powder before destruction (g)) × 100 ··· (1)

[0013] Here, the "amount of destruction" means the total mass (g) of the destroyed aerogel powder that has passed through a sieve with an aperture of 250 μm after 3 ml of aerogel powder adjusted to a particle size range of 250 μm to 1000 μm with a sieve is compressed by a universal testing machine under the conditions of a compression cross-sectional area of 1.34 cm 2 , a maximum load of 500 N, and a compression stress of 371.2 N / m 2 .

[0014] And the aerogel powder composition of the present invention satisfying the above configuration can increase the deformation rate defined by the following formula (2) for the aerogel powder contained therein, and can be, for example, 15% or more. Deformation rate (%) = {Change in deformation amount (mm) / Filling height of aerogel before deformation (mm)} × 100 ··· (2) Here, the "change in deformation amount" means the change amount (mm) of the filling height when the aerogel powder is compressed with a piston at 10 N in a cylindrical cylinder container having a bottom area of 1.34 cm 2 and filled to a position with a height of 16 mm, and the filling height of the aerogel before deformation is 16 mm.

[0015] By setting the composition of the silane compound that undergoes hydrolysis and condensation to 0 ≦ Qx ≦ 70, 30 ≦ Tx ≦ 100, 0 ≦ Dx < 30 and setting the destruction rate to 10% or less, an aerogel powder excellent in both flexibility and fracture resistance can be obtained.

[0016] In addition, since the deformation amount of the aerogel depends on the aerogel skeleton, it is related to the ratio of Qx, Tx, and Dx that affect the structure of the aerogel skeleton. The more Qx increases, the more the aerogel loses flexibility and becomes difficult to deform. Therefore, when Qx exceeds 70%, the aerogel powder contained in the aerogel composition of the present invention loses the flexibility characteristic of the aerogel, and the deformation amount becomes small.

[0017] On the one hand, increasing the proportion of Dx results in increased flexibility and easier deformability. However, when Dx exceeds 30%, manufacturing problems such as difficulty in gelation occur.

[0018] Moreover, the aerogel powder composition of a preferred embodiment of the present invention is an aerogel powder composition containing at least aerogel powder. The aerogel powder is composed of an aerogel that is a hydrolytic condensate of a silane compound. The mass percentages of the tetrafunctional silane compound, trifunctional silane compound, and bifunctional silane compound in the silane compound are 0 < Qx ≤ 50, 40 ≤ Tx < 100, and 0 ≤ Dx < 30 (where Qx + Tx + Dx = 100). The aerogel powder preferably has a destruction rate of 6% or less. By adopting this configuration, the aerogel powder has a destruction rate of 6% or less, further improving its resistance to destruction. At the same time, the deformation rate, for example, is 20% or more, so the flexibility can be further improved.

[0019] Furthermore, in the aerogel powder composition of a preferred embodiment of the present invention, the mass percentages of the tetrafunctional silane compound, trifunctional silane compound, and bifunctional silane compound in the silane compound are 0 < Qx < 50, 50 ≤ Tx < 100, and 0 ≤ Dx < 30 (where Qx + Tx + Dx = 100). The aerogel powder preferably has a destruction rate of 4% or less. By adopting this configuration, the aerogel powder has a destruction rate of 4% or less, further improving its resistance to destruction. At the same time, the deformation rate, for example, is 25% or more, so the flexibility can be further improved.

[0020] The inventors of the present invention have found that the structure of the aerogel of the present invention can be identified by solid 29 Si-NMR (DD-MAS method), that is, solid 29The percentages of the Q component, T component, and D component calculated from the signal area integration values derived from the Q component, T component, and D component measured by Si-NMR (DD-MAS method) were confirmed to substantially match the ratios of the mass percentages Qx, Tx, and Dx of the tetrafunctional silane compound, trifunctional silane compound, and bifunctional silane compound, which are the main raw materials for the production of the aerogel constituting the above-described aerogel powder, respectively.

[0021] 29 The measurement conditions of Si-NMR are as follows. Equipment: Solid NMR apparatus (JNM-ECA400 manufactured by JEOL Ltd.) Conditions: Proton resonance frequency: 390 MHz, time: 750 seconds per scan, number of integrations: 48 times, total measurement time: 10 hours; using the magic angle spinning method (DD) and the dipolar decoupling method (Magic Angle Spinning, Dipolar Dephasing method).

[0022] The aerogel powder composition of the present invention can be composed only of the aerogel powder obtained by pulverizing the aerogel, but can also be configured as a mixture or dispersion further containing additives for the purpose of imparting functionality, improving appearance, imparting decorativeness, etc. The content of the aerogel powder contained in the aerogel powder composition is preferably 80% by volume or more, more preferably 85% by volume or more, still more preferably 90% by volume or more, and even more preferably 95% by volume or more of the entire aerogel powder composition.

[0023] The additives to be contained in the aerogel powder composition are not particularly limited, and examples thereof include inorganic fillers such as silica particles, antistatic agents, lubricants, inorganic pigments, organic pigments, inorganic dyes, organic dyes, and the like.

[0024] Here, a tetrafunctional silane compound refers to a silane compound having four siloxane bonds (the number of oxygen atoms bonded to one silicon atom), a trifunctional silane compound refers to a silane compound having three siloxane bonds, and a bifunctional silane compound refers to a silane compound having two siloxane bonds.

[0025] Examples of the tetrafunctional silane compound include tetraalkoxysilane and tetraacetoxysilane. Desirable embodiments of the tetraalkoxysilane include those having 1 to 9 carbon atoms in the alkoxy group.

[0026] For example, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, etc. may be mentioned. These silane compounds may be used alone or in combination of a plurality. In the present invention, it is particularly preferable to use tetramethoxysilane (TMOS) as the tetrafunctional silane compound.

[0027] Examples of the trifunctional silane compound include trialkoxysilane and triacetoxysilane. Desirable embodiments of the trialkoxysilane include those having 1 to 9 carbon atoms in the alkoxy group.

[0028] For example, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, pentyltriethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, etc. may be mentioned.

[0029] These compounds may be used alone or in combination of a plurality. In the present invention, it is particularly preferable to use methyltrimethoxysilane (MTMS) as the trifunctional silane compound.

[0030] Examples of the bifunctional silane compound include dialkoxysilane and diacetoxysilane. Preferred embodiments of the dialkoxysilane include those having 1 to 9 carbon atoms in the alkoxy group.

[0031] Specifically, examples include dimethyldimethoxysilane, diethyldimethoxysilane, diisobutyldimethoxysilane, etc. These compounds may be used alone or in combination of a plurality. In the present invention, it is particularly preferable to use dimethyldimethoxysilane (DMDMS) as the bifunctional silane compound.

[0032] (1-2) Aerogel powder The aerogel powder contained in the aerogel powder composition of the present invention is a powder obtained by mechanically pulverizing an aerogel, and its particle size is 5 nm to 10 mm. This pulverized aerogel powder can be classified using ordinary means such as a sieve or wind power.

[0033] The average particle size of the classified aerogel powder can be appropriately adjusted and selected according to its intended use. For example, when used as a filler, it is preferably 20 μm to 3 mm, and more preferably 50 μm to 1 mm. Further, when the aerogel powder is used as a dispersion medium and dispersed in a liquid dispersion medium such as a paint to form an aerogel powder dispersion, the average particle size of the aerogel powder is preferably 5 to 100 μm, and more preferably 5 to 50 μm.

[0034] Here, the average particle size refers to the average particle size measured by a laser diffraction particle size distribution measuring device SALD-2300 (manufactured by Shimadzu Corporation).

[0035] The aerogel powder can be used by mixing a plurality of types of aerogel powders having different classified average particle sizes, for example, to increase the filling rate.

[0036] The shape of the aerogel powder is usually amorphous because it undergoes a grinding process, but it can be made into specific shapes such as spherical, plate-like, flake-like, fibrous, etc. The shape can be directly observed by SEM.

[0037] The elastic modulus of the aerogel powder is preferably 2.00 - 15.00 MPa, and more preferably 3.00 - 10.00 MPa. Here, the elastic modulus refers to the elastic modulus measured at 23°C and 50% RH atmosphere by a micro compression tester (manufactured by Shimadzu Corporation).

[0038] Since the aerogel powder has an elastic modulus within the above range, it can be highly filled into a predetermined container without being excessively ground by the pressure or high shear during processing. Also, when kneaded into a heat-insulating paint or the like, the desired heat-insulating property can be obtained.

[0039] (1 - 3) Characteristics of Aerogel Powder The aerogel powder composition of the present invention is an aerogel powder composition containing at least aerogel powder, having a breakage rate of 10% or less, preferably 6% or less, and more preferably 4% or less. Further, the aerogel powder composition of the present invention is preferably a uniform and low-turbidity mixture or dispersion when mixed with, for example, polyethylene glycol having a number average molecular weight of 200 of the same volume.

[0040] When the structure of the aerogel, which is the material of the aerogel powder of the present invention, is microscopically observed, it is mainly composed of a bulk part (skeleton part) filled with solids and pore parts penetrating in a three-dimensional network within the bulk part.

[0041] It is presumed that this structure exhibits a remarkable effect on the compressive force as a powder. It is also presumed that it is involved in the compatibility with polyethylene glycol having a number average molecular weight of 200.

[0042] The bulk part is composed of a continuum in which solids form a three-dimensional network by siloxane bonds. When approximating the lattice, which is the minimum unit of the three-dimensional network, as a cube, the average length of one side is 2 nm or more and 25 nm or less.

[0043] Note that the average length of one side is preferably 2 nm or more, 5 nm or more, 7 nm or more, 10 nm or more, and 25 nm or less, 20 nm or less, 15 nm or less.

[0044] Also, the pore part has a tubular shape that penetrates the above-mentioned bulk part. When approximating the pores as tubes and the average inner diameter when approximating the inner diameter of the tube as a circle, it is 5 nm or more and 100 nm or less. Note that the average inner diameter of the pores is preferably 5 nm or more, 7 nm or more, 10 nm or more, 20 nm or more, 30 nm or more, 50 nm or more, and 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less.

[0045] Here, the inner diameter of the above-mentioned tube has a dimension equal to or less than the mean free path (MFP) of the elemental molecules constituting air at atmospheric pressure.

[0046] Also, the porosity of the aerogel, that is, the ratio of the volume of the pore part to the volume of the entire aerogel, is 70% or more. As an example of the porosity, it may be 75% or more, 80% or more, 85% or more, 90% or more.

[0047] As long as the physical properties are satisfied, the aerogel of the present invention may include structures other than the above-mentioned bulk part and pore part. As an example, it may include voids different from the above-mentioned pore part.

[0048] Also, as another example, as long as the physical properties described later are satisfied, it can contain water, organic solvents, surfactants, catalysts, and decomposition products thereof remaining as inevitable components in manufacturing. Further, as another example, it can contain dust mixed in from the manufacturing space and manufacturing equipment as inevitable components in manufacturing.

[0049] The aerogel of the present invention preferably has a density of 0.15 g / cm 3 or less. Here, the density is determined by the mercury intrusion method. Since the aerogel of the present invention has a density of 0.15 g / cm 3 or less, its thermal conductivity is as low as 0.015 W / m·K or less, and it has excellent heat insulation properties.

[0050] The aerogel powder composition of the present invention is a mixture of aerogel powder and other powdery substances (such as pigments, dyes, etc.), and the aerogel powder dispersion of the present invention may also have a uniform dispersion state. Further, the aerogel powder composition of the present invention can be an aerogel powder dispersion in which aerogel powder is dispersed in a liquid dispersion medium with the aerogel powder as the dispersed phase (hereinafter, may be simply referred to as "aerogel powder dispersion"). As the liquid used as the dispersion medium, solvents commonly used in paints, adhesives, etc. such as water, ethyl alcohol, ethylene glycol, ethyl acetate, and toluene can be used. The aerogel powder can also be dispersed in a paint in which pigments, dyes, etc. are already dispersed.

[0051] The aerogel powder dispersion of the present invention can stably maintain a uniform dispersion state. For example, when aerogel powder is mixed and dispersed in polyethylene glycol having a number average molecular weight of 200 with the same volume to form an aerogel powder dispersion, and then the aerogel powder dispersion is allowed to stand for 30 minutes, the aerogel powder dispersion, which is the aerogel powder composition of the present invention, maintains a uniform dispersion state and has a turbidity of 300 degrees or less.

[0052] Here, in the aerogel powder dispersion, the "uniform dispersion state" means a state in which the aerogel powder is uniformly dispersed in the dispersion medium and does not precipitate at the bottom of the container containing the aerogel powder dispersion.

[0053] In addition, the "turbidity" referred to here can be easily determined by comparing a sample solution (aerogel powder dispersion) for measuring turbidity with a formazin turbidity standard solution visually or using a turbidimeter by the transmission scattering method. When the turbidity is close to 300, it can be compared by a turbidimeter. As the polyethylene glycol with a number average molecular weight of 200, which is the dispersion medium of the sample solution, commercially available products with a number average molecular weight of 180 to 220 can be used.

[0054] Since the above-mentioned aerogel powder dispersion maintains a uniform dispersion state and has a turbidity of 300 degrees or less, it indicates that the aerogel powder as the dispersed substance has a specific compatibility with polyethylene glycol having a number average molecular weight of 200. As a result, the aerogel powder contained in the aerogel powder composition of the present invention can exhibit good dispersibility in solvent paints and the like.

[0055] (2) Method for producing aerogel powder composition (2-1) Method for producing aerogel First, the method for producing aerogel, which is the material of the aerogel powder of the present invention, will be described.

[0056] The method for producing aerogel of the present invention is a method for producing aerogel including a sol generation step of adding a silicon compound to an aqueous solution containing an acid catalyst and hydrolyzing it to generate a sol, wherein the silicon compound contains at least a trifunctional silane compound among a tetrafunctional silane compound, a trifunctional silane compound, and a bifunctional silane compound.

[0057] As a specific method for producing the aerogel powder of the present invention, for example, a case where the sol generation step, the wet gel generation / molding step, the solvent exchange step, and the drying step are performed in this order can be mentioned. Hereinafter, each step will be described in detail.

[0058] (2-2) Sol generation step The sol generation step includes a step of adding various raw materials including a silicon compound (main raw material) into a predetermined solution and stirring and mixing them, thereby generating a sol.

[0059] (2-2-1) Siloxane bond constituent material (main raw material) The method for producing an aerogel of the present invention includes a sol generation step of mixing at least a trifunctional silane compound among a tetrafunctional silane compound, a trifunctional silane compound, and a bifunctional silane compound as a silicon compound serving as a main raw material for producing an aerogel at a predetermined ratio (mass percentage). More specifically, when the mass percentages of the tetrafunctional silane compound, the trifunctional silane compound, and the bifunctional silane compound are Qx, Tx, and Dx, respectively, a ratio satisfying 0 ≦ Qx ≦ 70, 30 ≦ Tx ≦ 100, 0 ≦ Dx < 30, preferably a ratio satisfying 0 < Qx ≦ 50, 40 ≦ Tx < 100, 0 ≦ Dx < 30, and more preferably a ratio satisfying 0 < Qx < 50, 50 ≦ Tx < 100, 0 ≦ Dx < 30 (where Qx + Tx + Dx = 100) is required to be included in the sol generation step.

[0060] (2-2-2) Mixing ratio of main raw materials (mass percentage) In the sol generation step, the silicon compound serving as the main raw material includes a sol generation step of mixing at least a trifunctional silane compound among a tetrafunctional silane compound, a trifunctional silane compound, and a bifunctional silane compound at a predetermined ratio (mass percentage). More specifically, when the mass percentages of the tetrafunctional silane compound, the trifunctional silane compound, and the bifunctional silane compound are Qx, Tx, and Dx, respectively, a ratio satisfying 0 ≦ Qx ≦ 70, 30 ≦ Tx ≦ 100, 0 ≦ Dx < 30, preferably a ratio satisfying 0 < Qx ≦ 50, 40 ≦ Tx < 100, 0 ≦ Dx < 30, and more preferably a ratio satisfying 0 < Qx < 50, 50 ≦ Tx < 100, 0 ≦ Dx < 30 (where Qx + Tx + Dx = 100).

[0061] Figure 1 shows the appropriate ranges of Qx, Tx, and Dx, which are the mass percentages of a preferred tetrafunctional silane compound, trifunctional silane compound, and difunctional silane compound, respectively, mixed in the mixing step of the method for producing an aerogel of the present invention, in a triangular diagram with Qx, Tx, and Dx as the coordinate axes. Note that the line segment (0 ≦ Qx ≦ 40, 30 ≦ Tx ≦ 70, Dx = 30%) connecting the two "○ (open circles)" shown in Figure 1 is indicated by a dashed line, but such a dashed line is not included in either the appropriate range (Region I) or the preferred ranges (Region II and Region III) of the present invention.

[0062] Region I (hatched with an upward slope to the right) shown in Figure 1 represents the appropriate range of the present invention, that is, the region enclosed by 0 ≦ Qx ≦ 70, 30 ≦ Tx ≦ 100, 0 ≦ Dx < 30 (where Qx + Tx + Dx = 100). Also, Region II (hatched with a downward slope to the right) represents the preferred range of the present invention, that is, the range enclosed by 0 < Qx ≦ 50, 40 ≦ Tx < 100, 0 ≦ Dx < 30 (where Qx + Tx + Dx = 100). By mixing silicon compounds at mass percentages that satisfy the ranges of Region I and Region II, defects such as cracks are few, and the density is 0.15 g / cm 3 The following aerogel can be produced. An aerogel powder produced at the mixing ratios of Region I and Region II and having a fracture rate of 10% or less has excellent flexibility and fracture resistance. In particular, Region I shown in Figure 1 is the region where an aerogel powder with a fracture rate of 10% or less and a deformation rate of 15% or more can be obtained. Also, Region II is the region where an aerogel powder with a fracture rate of 6% or less and a deformation rate of 20% or more can be obtained. Furthermore, Region III (hatched with horizontal lines) shown in Figure 1 represents a further preferred range of the present invention, that is, if silicon compounds are mixed at mass percentages that satisfy the range enclosed by 0 < Qx < 50, 50 ≦ Tx < 100, 0 ≦ Dx < 30 (where Qx + Tx + Dx = 100), it is also possible to obtain an aerogel powder with a fracture rate of 4% or less and a deformation rate of 25% or more.

[0063] (2-2-3) Auxiliary materials and sol formation conditions in the sol formation step In the sol generation step, as the main raw materials, a tetrafunctional silane compound, a trifunctional silane compound, and a bifunctional silane compound are mixed at the above-mentioned predetermined mixing ratio and added to a solution containing water and a surfactant. By this preparation, the silane compounds are hydrolyzed and condensed to form a sol containing siloxane bonds. Note that the solution to be prepared may contain an acid, a nitrogen compound, an organic solvent, an organic compound (for example, saccharides) and / or an inorganic compound (for example, salts).

[0064] The surfactant contributes to forming a microphase separation structure during the sol generation process and forming the bulk part and the pore part that constitute the aerogel described later. As the surfactant that can be used in the production of the aerogel, a nonionic surfactant, an ionic surfactant, etc. can be used.

[0065] Examples of the ionic surfactant can include a cationic surfactant, an anionic surfactant, an amphoteric surfactant, etc. It is particularly preferable to use a nonionic surfactant as the surfactant.

[0066] The addition amount of the surfactant to the solution to be prepared depends on the type and mixing ratio of the silane compounds and the type of the surfactant, but it is preferably in the range of 0.001 to 100 parts by mass, more preferably in the range of 0.01 to 90 parts by mass, and still more preferably in the range of 0.1 to 80 parts by mass with respect to 100 parts by mass of the total amount of the silane compounds as the main raw materials.

[0067] The acid acts as a catalyst during hydrolysis and can accelerate the reaction rate of hydrolysis. Specific examples of the acid include inorganic acids, organic acids, and organic acid salts.

[0068] Examples of the inorganic acid include hydrochloric acid, sulfuric acid, sulfurous acid, nitric acid, hydrofluoric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, bromic acid, chloric acid, chlorous acid, hypochlorous acid, etc.

[0069] Examples of the organic acid include carboxylic acids such as acetic acid, formic acid, propionic acid, oxalic acid, malonic acid, succinic acid, citric acid, malic acid, adipic acid, azelaic acid, etc.

[0070] Examples of the organic acid salts include aluminum acid phosphate, magnesium acid phosphate, zinc acid phosphate, etc. These acids may be used alone or in combination of two or more. In the present invention, it is preferable to use acetic acid, which is an organic acid, as the acid.

[0071] Also, the addition concentration of the acid with respect to the entire solution to be prepared is preferably in the range of 0.0001 mol / L to 0.1 mol / L, more preferably in the range of 0.0005 mol / L to 0.05 mol / L, and still more preferably in the range of 0.001 mol / L to 0.01 mol / L.

[0072] The nitrogen compound can also be used as a compound that generates a basic catalyst during heating in the wet gel formation and shaping process. Specifically, examples include amide compounds such as urea, formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and heterocyclic compounds such as hexamethylenetetramine. In particular, urea can be preferably used in terms of contributing to the formation of the fine pore structure of the aerogel and realizing homogeneous gelation.

[0073] The addition amount of the nitrogen compound is not particularly limited. For example, with respect to 100 parts by mass of the total amount of the silane compound as the main raw material, the addition amount of the nitrogen compound is preferably in the range of 1 to 200 parts by mass, and more preferably in the range of 2 to 150 parts by mass.

[0074] As the organic solvent, alcohols such as methanol, ethanol, n-propanol, 2-propanol, n-butanol, 2-butanol, and t-butanol can be used. These may be used alone or in combination of two or more. Also, from the viewpoint of compatibility, the addition amount of the organic solvent with respect to the solution to be prepared is more preferably in the range of 0 to 10 mol, particularly 0 to 9 mol, and still more preferably in the range of 0 to 8 mol with respect to 1 mol of the total amount of the silicon compound as the main raw material.

[0075] The solution temperature and time required for the sol generation process depend on the types and amounts of silane compounds, surfactants, water, acids, nitrogen compounds, organic solvents, etc. in the mixed solution. For example, in a temperature environment of 0°C to 70°C, a range of 0.05 hours to 48 hours is acceptable, and it is preferably treated at a temperature environment of 20 to 50°C for 0.1 hours to 24 hours.

[0076] When urea has already been added as the nitrogen compound, in order to make urea function as a gelation catalyst, the solution temperature in the sol generation process is preferably carried out at less than 40°C from the viewpoint of suppressing the hydrolysis of urea (the reaction that releases ammonia and carbon dioxide proceeds at about 50°C or higher).

[0077] Through the sol generation process carried out under such conditions, the silane compound is hydrolyzed, and a liquid sol can be generated as a whole. In addition, the auxiliary materials and / or decomposition products of the auxiliary materials used in the sol generation process may be mixed as inevitable components in the manufactured aerogel.

[0078] (2-3) Wet gel generation and shaping process The wet gel generation and shaping process can be roughly divided into a process of adding a basic catalyst to the liquid sol manufactured in the above-mentioned sol generation process, a process of pouring the liquid sol into a mold to obtain a desired shape, and a process of generating a wet gel by curing the liquid sol poured inside the mold. When a nitrogen compound has already been added as a compound that generates a basic catalyst in the sol generation process, the process of adding a basic catalyst to the liquid sol can also be omitted.

[0079] Examples of the basic catalyst include ammonium compounds such as ammonium hydroxide, ammonium fluoride, ammonium chloride, ammonium bromide, tetramethylammonium, tetraethylammonium, tetrapropylammonium (including isomers), tetrabutylammonium (including isomers), etc.; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, etc.; basic sodium phosphate salts such as sodium metaphosphate, sodium pyrophosphate, sodium polyphosphate, etc.; aliphatic amines such as allylamine, diallylamine, triallylamine, isopropylamine, diisopropylamine, ethylamine, diethylamine, triethylamine, 2-ethylhexylamine, 3-ethoxypropylamine, diisobutylamine, 3-(diethylamino)propylamine, di-2-ethylhexylamine, 3-(dibutylamino)propylamine, tetramethylethylenediamine, t-butylamine, sec-butylamine, propylamine, 3-(methylamino)propylamine, 3-(dimethylamino)propylamine, 3-methoxyamine, dimethylethanolamine, methyldiethanolamine, diethanolamine, triethanolamine, etc.; and nitrogen-containing heterocyclic compounds such as morpholine, N-methylmorpholine, 2-methylmorpholine, piperazine and its derivatives, piperidine and its derivatives, imidazole and its derivatives. The basic catalyst may be used alone or in combination of two or more.

[0080] The addition amount of the basic catalyst is preferably 0.001 to 5 parts by mass, and particularly preferably 0.01 to 4 parts by mass, based on 100 parts by mass of the total amount of the main raw materials. When the addition amount is less than 0.001 part by mass, the reaction from the sol to the wet gel tends not to be sufficiently promoted. When it exceeds 5 parts by mass, the formed siloxane bond may be cleaved, resulting in a delay in the gelation time and heterogeneity. In particular, an aqueous solution of tetramethylammonium is preferable in that it has a high reaction-promoting effect as a catalyst and can form the reaction from the sol to the wet gel in a short time with few defects.

[0081] The step of pouring the solution added with the basic catalyst into the mold is a step for obtaining the shape of the desired aerogel product. As the mold, any of metal, synthetic resin, wood, and paper can be used, but it is preferable to use a synthetic resin in terms of both flatness of the shape and releasability. Examples of the synthetic resin include polystyrene, polyethylene, polypropylene, polyethylene terephthalate (PET), polycarbonate (PC), silicone, and polytetrafluoroethylene (PTFE).

[0082] Since the mold is for obtaining the shape of the desired aerogel product, it has a concavo-convex shape corresponding to the concavo-convex of the shape of the desired aerogel product. For example, when the shape of the desired aerogel product is plate-shaped (rectangular parallelepiped), a concave tray with one end open can be used as the mold. Also, the mold may be a combined mold composed of a plurality of molds, such as a so-called injection mold.

[0083] As an example, there is a two-piece combined mold in which a concave mold and a convex mold are used facing each other, and the combined mold may be such that the inner surface of the concave mold and the outer surface of the convex mold are separated at a predetermined interval. As a result, the solution (solution composed of sol and basic catalyst) may be poured into the internal space of the combined mold and sealed for a predetermined time.

[0084] Also, when a concave tray with one end open is used as the mold, a flat plate (plate) covering the entire open (flat) surface of the concave tray may be prepared as the second mold, and it may be used as a two-piece combined mold such that the open surface of the concave tray and the second mold face each other. As a result, the solution (solution composed of sol and basic catalyst) may be poured into the inside of the combined mold and sealed for a predetermined time.

[0085] Following the step of filling the mold with the solution added with the basic catalyst, there is an aging step of promoting the crosslinking reaction of the solution inside the mold to generate a wet gel and curing it.

[0086] Curing involves promoting the cross-linking reaction of the wet gel with a predetermined amount of energy over a predetermined period of time. An example of the energy is heat (temperature), and heating at 30 to 90 °C, preferably 40 to 80 °C, is used. The heating may be by heater heating or steam heating with water or an organic solvent.

[0087] Another example of the energy includes the application of electromagnetic waves such as infrared rays, ultraviolet rays, microwaves, gamma rays, and the application of electron beams. These energies may be used alone or in combination with multiple means.

[0088] The time required for curing depends on the composition of the silicon compound, the types and amounts of surfactants, water, acids, nitrogen compounds, organic solvents, basic catalysts, etc., and further on the type and density of the energy, but it is in the period between 0.01 hours and 7 days. When the type of the basic catalyst and the type of the energy are optimized, gelation may be completed in 0.01 hours to 24 hours.

[0089] Also, the curing may be a curing in which heat (temperature) and time are changed in multiple steps. Note that the materials used in the wet gel generation / molding step and / or the decomposition products of the materials may be mixed as inevitable components in the produced aerogel.

[0090] (2-4) Gel pulverization step In the gel pulverization step, the gel obtained in the above step is pulverized to a predetermined size. The above gel can be pulverized, for example, by a Henschel mixer under appropriate conditions (rotation speed and time).

[0091] The gel may be generated in the mixer and pulverized as it is. Alternatively, the gel may be generated in a sealable container and an oscillation device such as a shaker may be used. A jet mill, a roller mill, or a bead mill can also be used to adjust the particle size. The pulverized gel may be washed to reduce impurities such as unreacted substances and by-products.

[0092] (2-5) Solvent exchange step The solvent exchange step is an essential step in the method for producing an aerogel of the present invention for producing an aerogel by exchanging water and / or an organic solvent present on the surface and inside of a wet gel with an organic solvent that can be dried at normal pressure. In order to reduce the capillary force expressed by the Young-Laplace equation as much as possible and suppress the shrinkage of the gel due to drying, it is a step of substituting with an organic solvent (hydrocarbon solvent) having a low surface energy. Further, the solvent exchange step may be performed after taking out from the above-described mold, or may be performed inside the mold.

[0093] Since the hydrocarbon solvent used for solvent exchange is immiscible with water, in the solvent exchange step, first, water and / or an organic solvent present on the surface and inside of the wet gel is exchanged with an intermediate solvent such as alcohol that is miscible with the hydrocarbon solvent, and then this intermediate solvent is exchanged with an organic solvent (hydrocarbon solvent) having a low surface energy.

[0094] Examples of the alcohol used as the intermediate solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol (IPA), and butanol.

[0095] In the solvent exchange step, in order to suppress the shrinkage damage of the gel in the subsequent drying step, water (or organic solvent) on the surface and inside of the wet gel is replaced with an organic solvent having a surface tension of 45 mN / m or less at 20°C.

[0096] For example, dimethyl sulfoxide (43.5 mN / m), cyclohexane (25.2 mN / m), isopropyl alcohol (21 mN / m), heptane (20.2 mN / m), pentane (15.5 mN / m), etc. can be mentioned.

[0097] The organic solvent used in the solvent exchange step may have a surface tension at 20°C of 45 mN / m or less, 40 mN / m or less, 35 mN / m or less, 30 mN / m or less, 25 mN / m or less, 20 mN / m or less, 15 mN / m or less, and may be 5 mN / m or more, 10 mN / m or more, 15 mN / m or more, 20 mN / m or more.

[0098] Among these, it is particularly preferable to use an organic solvent containing an aliphatic hydrocarbon having a surface tension at 20 °C in the range of 18 to 40 mN / m. The organic solvent can be used alone or in combination of two or more.

[0099] The amount of the solvent used in the solvent exchange step depends on the temperature and apparatus (container) for the solvent exchange, but it is desirable to use an amount 2 to 100 times the volume of the wet gel. The solvent exchange is not limited to once and may be performed multiple times. Also, as the method of solvent exchange, any of total replacement, partial replacement, and circulation replacement methods may be used.

[0100] Also, when performing the solvent exchange multiple times, for each time, the type of the organic solvent, temperature, and treatment time may be set independently. Note that the materials used in the solvent exchange step and / or the decomposition products of the materials may be mixed as inevitable components in the produced aerogel.

[0101] As an example of a specific embodiment, the solvent exchange step can be performed according to the following procedure. First, the wet gel is immersed in a methanol (MeOH) solution corresponding to 5 times the volume of the wet gel and the solvent exchange is performed under the conditions of 60 °C for 8 hours. The solvent exchange using the MeOH solution is preferably repeated multiple times (for example, 5 times). The purpose of the solvent exchange using the MeOH solution is to remove the moisture, unreacted components of the raw materials, and by-products in the wet gel.

[0102] Next, the wet gel after performing the solvent exchange using the MeOH solution is immersed in an IPA / Hep mixed solution corresponding to 5 times the volume of the wet gel, which is a mixture of isopropyl alcohol (IPA) and heptane (Hep) in a volume ratio of 1:4 to 1:3, and further solvent exchange is performed under the conditions of 60 °C for 8 hours. Since MeOH does not directly mix with Hep, the MeOH in the wet gel can be removed using the IPA / Hep mixed solution.

[0103] After that, the wet gel that has undergone solvent exchange using an IPA / Hep mixed solution is immersed in a Hep solution corresponding to 5 times the volume of the wet gel, and further solvent exchange is performed under the conditions of 60°C for 8 hours. The solvent exchange using the Hep solution is preferably repeated a plurality of times (for example, 2 times). The purpose of the solvent exchange using the Hep solution is to replace all the solvents in the wet gel with the Hep solution, which is a dry solvent.

[0104] (2-6) Drying step The drying step is a step of drying the above-described solvent-exchanged wet gel to obtain an aerogel in a predetermined state. The drying method is not particularly limited, but the supercritical drying method has problems such as the equipment becoming large-sized and the manufacturing cost being extremely high, making mass production difficult. Therefore, in the drying step of the present invention, the supercritical drying method is not applied, and the atmospheric pressure drying method or the freeze-drying method is used, and particularly the atmospheric pressure drying method is preferable. By using this drying method, an aerogel powder with a lower compression fracture rate than the supercritical drying method can be obtained.

[0105] Note that the atmospheric pressure refers to the surface atmospheric pressure of 300 hPa to 1100 hPa, and there is no limitation on the altitude at which the present invention is implemented as long as it is the surface. In other words, as a drying method, drying by reducing the pressure to about 300 hPa is also included in the present invention.

[0106] From the above, by going through the above-described steps (2-1) to (2-6), the aerogel of the present invention can be manufactured at a low density (0.15 g / cm 3 or less) with a high elastic modulus.

[0107] (2-7) Final pulverization step In order to adjust the average particle size of the aerogel powder, a final pulverization step can also be provided. The pulverization in the final pulverization step can be performed by using the apparatus used in the step (2-4) and appropriately determining the pulverization conditions. It is also preferable to perform classification by sieving or wind power. The gel pulverization step (2-4) can be omitted and pulverized only in this step.

[0108] (2-8) Aerogel powder composition adjustment process An aerogel powder composition can be produced by appropriately adding necessary additives to the aerogel powder obtained in the previous process.

[0109] (2-9) Uses of the aerogel powder composition The aerogel powder composition of the present invention can be applied in various ways, for example, by filling it into heat-insulating windows, heat-insulating building materials (paints, heat-insulating boards), etc.

[0110] What has been described above is merely an example of an embodiment of this invention, and various modifications can be made within the scope of the claims.

Examples

[0111] Hereinafter, the examples of the present invention will be specifically described. The evaluation was carried out in an atmosphere of 23°C and 50% RH unless otherwise specified.

[0112] <Examples 1 to 11> 3.28 g of a nonionic surfactant (Pluronic PE9400, manufactured by BASF) was dissolved in 28.96 g of a 0.005 mol / L acetic acid aqueous solution, and then 4.00 g of urea (manufactured by Nacalai Tesque) as a hydrolyzable compound was further added and dissolved. After adding 10.00 g of a silicon compound as the main raw material to this aqueous solution, it was stirred and mixed at room temperature for 60 minutes to cause a hydrolysis reaction of the silicon compound to generate a sol (sol generation step).

[0113] The silicon compound was selected from tetramethoxysilane, a tetrafunctional silane compound (methyl orthosilicate manufactured by Tama Chemical Industry Co., Ltd., hereinafter may be abbreviated as "TMOS"), methyltrimethoxysilane, a trifunctional silane compound (DOWSIL Z-6366 Silane manufactured by Toray Dow Corning Co., Ltd., hereinafter may be abbreviated as "MTMS"), and dimethyldimethoxysilane, a bifunctional silane compound (manufactured by Tokyo Chemical Industry Co., Ltd., product code: D1052, hereinafter may be abbreviated as "DMDMS"), and added in terms of the mass percentage Qx of the tetrafunctional silane compound, the mass percentage Tx of the trifunctional silane compound, and the mass percentage Dx of the bifunctional silane compound shown in Table 1.

[0114] Note that both TMOS and MTMS were purified by vacuum distillation before use. Thereafter, the produced sol was allowed to stand at 60°C in a sealed container to be gelled. Thereafter, the wet gel was aged by continuously allowing it to stand for 96 hours (wet gel formation and molding process).

[0115] The wet gel was immersed in a methanol (MeOH) solution corresponding to 5 times its volume, and the solvent exchange was repeated 5 times under the condition of 60°C for 8 hours. Thereafter, it was immersed in an IPA / Hep mixed solution corresponding to 5 times the volume of the wet gel, in which isopropyl alcohol (IPA) and heptane (Hep) were mixed at a volume ratio of 1:4 to 1:3, and the solvent exchange was further performed under the condition of 60°C for 8 hours. Thereafter, it was immersed in a Hep solution corresponding to 5 times the volume of the wet gel, and the solvent exchange was further repeated 2 times under the condition of 60°C for 8 hours.

[0116] Note that both methanol and isopropyl alcohol used for the solvent exchange were those manufactured by Nacalai Tesque.

[0117] The wet gel was dried under atmospheric pressure (atmospheric pressure drying) by the following method. As the low surface tension solvent, heptane (manufactured by Nacalai Tesque) was used, and the solvent in the wet gel was exchanged (replaced) with the low surface tension solvent.

[0118] The wet gel was placed in a low surface tension solvent in an amount sufficient for the wet gel to be fully immersed, heated to near 55°C of the boiling point, and refluxed for 8 hours. After refluxing, it was cooled to room temperature, and then the low surface tension solvent in the container was removed, replaced with a fresh low surface tension solvent, and further refluxed. This operation was repeated more than 3 times to complete the solvent exchange with the low surface tension solvent (solvent exchange step).

[0119] Next, after the solvent in the wet gel was exchanged (replaced) with a low surface tension solvent, it was placed in a container (dryer) capable of controlling the evaporation rate, and drying was started. Drying was terminated when the gel mass became constant, and an aerogel was produced (drying step).

[0120] The obtained aerogel was pulverized with a Henschel mixer to obtain the aerogel powders of Examples 1 to 11. At this time, for the levels where Dx was not 0, the particle size of the powder was visually more uniform. Also, the elastic modulus of the aerogel powders of Examples 1 to 11 was all in the range of 2.00 to 15.00 MPa (final pulverization step).

[0121] For reference, Comparative Example 1 was prepared by using a main raw material composed of a tetrafunctional silane compound and a bifunctional silane compound at a mass percentage outside the proper range (Region I in FIG. 1) of the present invention and producing an aerogel powder by the same production method as in Example 1. Also, Comparative Example 2 was prepared by drying by the supercritical method to produce an aerogel powder.

[0122] Regarding the obtained aerogel powder, the evaluation of the fracture rate (%) in the following compression fracture test and the deformation rate (%) in the compression deformation test was carried out. The evaluation was carried out in an atmosphere of 23°C and 50% RH unless otherwise specified. The evaluation results are shown in Table 1.

[0123] (Evaluation method)

[0124] <Compression fracture test> The prepared aerogel powder was sieved through a sieve with an aperture of 250 μm and a sieve with an aperture of 1000 μm, and only the aerogel powder having a particle size in the range of 250 μm to 1000 μm was collected. 3 ml of the collected aerogel powder was weighed, and the weighed aerogel powder was compressed by a universal testing machine (compression fracture testing machine) shown in Fig. 2. The compression cross-sectional area was 1.34 cm 2 , the maximum load was 500 N, and the compression stress was 371.2 N / m 2 . After compression, it was sieved through a sieve with an aperture of 250 μm, and the amount of the broken powder (breakage amount) that passed through the sieve was measured. The measured breakage amount (g) was substituted into the following formula (1) to calculate the breakage rate (%). Then, the breakage resistance (the property of being difficult to break) was evaluated from the numerical value of this breakage rate (%). Breakage rate (%) = (breakage amount (g) / mass of aerogel powder before breakage (g)) × 100 ·· (1)

[0125] <Compression deformation test> The prepared aerogel powder was filled in a cylindrical cylinder container having a bottom area of 1.34 cm 2 up to a height of 16 mm, and using a piston having substantially the same area as the bottom area, the change amount (mm) of the filling height when compressed with a 10 N load by this piston was measured. The filling height of the aerogel before deformation was 16 mm. The same universal testing machine as that used in the compression fracture test was used for the apparatus. After measurement, the deformation amount was measured by the following formula (2), and the measured deformation amount was substituted into the following formula to calculate the deformation rate. Then, the flexibility was evaluated from the numerical value of this deformation rate. Deformation rate (%) = {change amount of deformation (mm) / filling height of aerogel before deformation (mm)} × 100 ·· (2)

[0126]

Table 1

[0127] <Dispersibility evaluation: uniformity and turbidity> The monolithic aerogel was crushed, and the aerogel powder was sieved and classified so that the average particle size became 50 to 60 μm. 5 ml of the thus adjusted aerogel powder was added to 5 ml of polyethylene glycol 200 as a dispersion medium and stirred to prepare an aerogel powder dispersion. Then, it was allowed to stand for 30 minutes, and the uniform state of the dispersion at that time was visually confirmed. The turbidity was visually compared with a formazin standard solution having a turbidity of 300. As the polyethylene glycol 200, a first-grade product of Fuji Film Wako Pure Chemical Industries, Ltd. was used.

[0128] The aerogel powder dispersions prepared using the aerogel powders of Examples 1 to 11 and Comparative Example 1 of the present invention had a uniform dispersion state and low turbidity. However, the aerogel powder dispersion prepared using the aerogel powder of Comparative Example 2 had a non-uniform dispersion state and high turbidity. Also, the aerogel powders of Examples 1 to 11 were not destroyed during stirring in the dispersion medium.

[0129] As described above, it can be seen that the aerogel powder contained in the aerogel powder composition of the present invention is excellent in flexibility and resistance to breakage against compressive force, and has a uniform and stable dispersion state in a dispersion medium such as polyethylene glycol having an average molecular weight of 200, low turbidity, and good compatibility.

Explanation of Reference Numerals

[0130] 1 Universal testing machine 2 Aerogel powder P Pressure

Claims

1. An aerogel powder composition containing at least aerogel powder, wherein the aerogel powder is composed of an aerogel which is a hydrolytic condensate of a silane compound, and when the mass percentages of the tetrafunctional silane compound, trifunctional silane compound, and bifunctional silane compound in the silane compound are Qx, Tx, and Dx, respectively, 0 ≦ Qx ≦ 70, 30 ≦ Tx ≦ 100, 0 ≦ Dx < 30 (where Qx + Tx + Dx = 100); the aerogel powder has a destruction rate defined by the following formula (1) of 10% or less; the aerogel has a skeleton part forming a three-dimensional network by siloxane bonds and a pore part penetrating in a three-dimensional network shape within the skeleton part, the aerogel powder composition. Destruction rate (%) = (amount of destruction (g) / mass of aerogel powder before destruction (g)) × 100... (1) Here, the "destruction amount" means the total mass (g) of the broken aerogel powder that has passed through a sieve with an opening of 250 μm after 3 ml of aerogel powder adjusted to a particle size range of 250 μm to 1000 μm by a sieve is compressed under the conditions of a compression cross-sectional area of 1.34 cm ２ , a maximum load of 500 N, and a compression stress of 371.2 N / m ２ by a universal testing machine and then sieved through a sieve with an opening of 250 μm after compression.

2. The aerogel powder composition according to claim 1, wherein the aerogel powder has a deformation rate defined by the following formula (2) of 15% or more. Deformation rate (%) = {amount of deformation change (mm) / filling height of aerogel before deformation (mm)} × 100... (2) Here, the "amount of deformation change" refers to the change amount (mm) of the filling height when the aerogel powder is filled up to a position of 16 mm in height in a cylindrical cylinder container having a bottom area of 1.34 cm ２ and compressed with a piston at 10 N. The filling height of the aerogel before deformation is 16 mm.

3. The silane compound is 0 < Qx ≦ 50, 40 ≦ Tx < 100, 0 ≦ Dx < 30 (where Qx + Tx + Dx = 100), and the aerogel powder has a destruction rate of 6% or less, the aerogel powder composition according to claim 1.

4. The aerogel powder composition according to claim 3, wherein the aerogel powder has a deformation rate defined by the following formula (2) of 20% or more. Deformation rate (%) = {amount of deformation change (mm) / filling height of aerogel before deformation (mm)} × 100... (2) Here, the "amount of deformation change" refers to the change amount (mm) of the filling height when the aerogel powder is filled up to a position of 16 mm in height in a cylindrical cylinder container having a bottom area of 1.34 cm ２ and compressed with a piston at 10 N. The filling height of the aerogel before deformation is 16 mm.

5. The aerogel powder composition according to any one of claims 1 to 4, wherein the aerogel powder is composed of an aerogel dried by an atmospheric pressure drying method.

6. The aerogel powder composition according to any one of claims 1 to 5, wherein the aerogel powder composition is a mixture of the aerogel powder and other powder particles.

7. The aerogel powder composition according to any one of claims 1 to 5, wherein the aerogel powder composition is an aerogel powder dispersion in which the aerogel powder is dispersed as a dispersed phase in a liquid dispersion medium.

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