WO2021045483A1 - Method for manufacturing aerogel blanket - Google Patents

Abstract

The present invention relates to a method for manufacturing an aerogel blanket, the method comprising the steps of: 1) introducing a catalyzed sol and a substrate for a blanket into a reaction container to impregnate the substrate for a blanket with the catalyzed sol; and 2) gelling the substrate for a blanket, impregnated with the catalyzed sol, by rotation, wherein the catalyzed sol comprises a silica precursor composition, the silica precursor composition comprising: a silicate containing a hydrophobic group; and a tetraalkyl silicate, and wherein the molar ratio of the silicate containing a hydrophobic group and the tetraalkyl silicate is 60:40 to 98:2.

Description

Airgel blanket manufacturing method

[Mutual citation with related application]

The present invention is based on Korean Patent Application No. 10-2019-0109158 filed on September 3, 2019, Korean Patent Application No. 10-2019-0121147 filed on September 30, 2019, and July 9, 2020. It claims the benefit of priority based on the applied Korean patent application No. 10-2020-0084762, and all contents disclosed in the documents of the Korean patent application are included as part of this specification.

[Technical field]

The present invention relates to a method for manufacturing an airgel blanket, and without performing a surface modification step requiring excessive use of an expensive surface modifier, the hydrophobicity of the produced airgel blanket can be secured, and further, an airgel blanket capable of normal pressure drying. It relates to a manufacturing method.

^{Aerogel is an ultra-porous, high specific surface area (≥500 m 2} /g) material with a porosity of about 90 to 99.9% and a pore size in the range of 1 to 100 nm. Since it is a material having an airgel material, as well as research on the development of aerogel material, application research as a transparent insulation material and environment-friendly high-temperature insulation material, ultra-low dielectric thin film for highly integrated devices, catalyst and catalyst carrier, electrode for super capacitor, and electrode material for seawater desalination are also actively progressing. .

The biggest advantage of airgel is that it is super-insulation, which has a thermal conductivity of 0.300 W/m·K or less, which is lower than that of organic insulation materials such as conventional styrofoam, and that it prevents fire vulnerability, which is a fatal weakness of organic insulation materials, and harmful gas generation in case of fire. Is that it can be solved.

In general, airgels are manufactured by preparing a hydrogel from silica precursors such as water glass and alkoxysilane series (TEOS, TMOS, MTMS, etc.), and removing liquid components inside the hydrogel without destroying the microstructure.

In particular, a hydrophobic silica airgel blanket in which a hydrophobic silica aerogel is formed in a fiber is widely used in construction or industrial sites as a functional insulating material that prevents corrosion by moisture, and such a hydrophobic silica airgel blanket is generally used in the steps of preparing a silica sol solution, It is produced through a gelling step, a aging step, a surface modification step, and a drying step.

However, the surface modification step in the conventional manufacturing method as described above uses a large amount of organic solvent and an expensive surface modifier, and the process is complicated and requires a long process time, so economical efficiency and productivity are not good. The ammonia generated when the surface of the airgel is reformed reacts with carbon dioxide used in the supercritical stage to form ammonium carbonate salts, causing problems such as blocking the piping of the supercritical drying equipment, thereby hindering the efficiency of the process. In addition, since a large amount of ammonia was present in the waste solution generated after drying, it was impossible to immediately reuse the waste solution. In order to reuse the waste solution, it took a long time in the purification process and the purification cost was increased.

In addition, among the conventional manufacturing methods as described above, the drying step is performed by supercritical drying, which corresponds to an expensive process, and it is not easy to secure safety because it is performed under high pressure conditions, and only batch production is possible. As a result, it can be a cause of lowering productivity. Thus, a normal pressure drying method has been proposed to replace supercritical drying, but since the surface modification reaction by the surface modification step starts from the outermost part of the airgel, it is difficult to introduce a sufficient amount of surface modifier to the inside of the airgel. Therefore, in the case of the atmospheric drying method, there is a problem that it is difficult to secure the same physical properties as that of the supercritical drying method due to the adsorption of moisture due to hydrogen bonding between the hydroxyl group present on the surface inside the airgel and the moisture in the solvent.

Meanwhile, the airgel blanket may be manufactured using a gel casting method and a method in which airgel powder or granules are prepared and then immersed in a substrate for a blanket using a binder. As a commercially available technology, a gel casting method using a roll-to-roll method is known. However, in order to manufacture an airgel blanket by the roll-to-roll method, a conveyor belt must be included in the equipment so that the catalyst can be cast and gelled completely, and the conveyor belt must be connected until the gelation is completed. Therefore, there is a problem that the scale of the equipment becomes enormous in the mass production stage. In addition, as the length of the airgel blanket to be produced increases, the length of the conveyor belt becomes longer and the overall manufacturing time becomes longer due to the longer gelation time.In particular, the thinner the airgel blanket is, the longer the length is. Since this becomes longer, there is a problem that the manufacturing time is affected by the thickness and length of the blanket.

[Prior technical literature]

[Patent Literature]

(Patent Document 1) KR10-2012-0070948A

The present invention was conceived to solve the above conventional problems, and in manufacturing an airgel blanket, a large amount of organic solvent and an expensive surface modifier are used, and the process is complicated and requires a long process time, thereby improving economic efficiency and productivity. It is an object of the present invention to provide a method of manufacturing an airgel blanket that can omit the inhibiting surface modification step.

In addition, an object of the present invention is to provide a method for manufacturing a silica airgel blanket that can reduce energy consumption by omitting the surface modification step, and use a simplified manufacturing facility since the surface modification supply facility is not required by omitting the above step. .

In addition, it is an object of the present invention to provide a method of manufacturing an airgel blanket capable of drying in a normal pressure drying method as well as supercritical drying when manufacturing an airgel blanket.

In addition, in the present invention, in manufacturing an airgel blanket by the gel casting method, by performing gelation while rotating the substrate for blanket impregnated with the sol catalyzed in the gelling process, the manufacturing time can be greatly reduced, and It is an object of the present invention to provide an airgel blanket manufacturing method capable of simplifying manufacturing equipment and preventing thickness and length from affecting manufacturing time.

In addition, the present invention further improves the uniformity of the aerogel formed in the blanket substrate by allowing the airgel to be formed uniformly in the blanket substrate by rotating the substrate for blanket impregnated with the catalytic sol. An object of the present invention is to provide a method of manufacturing an airgel blanket in which thermal conductivity may be uniformly displayed throughout the airgel blanket and the thermal conductivity of the airgel blanket may be improved.

In order to solve the above problems, the present invention includes: 1) introducing the catalyzed sol and a blanket substrate into a reaction vessel, and impregnating the catalyst with the blanket substrate with the catalyzed sol; And 2) rotating and gelling a substrate for a blanket impregnated with the catalyzed sol, wherein the catalyzed sol includes a silica precursor composition, and the silica precursor composition includes a silicate and tetrahydrophobic group. It includes an alkyl silicate, and the molar ratio of the silicate including the hydrophobic group and the tetraalkyl silicate is 60:40 to 98:2 provides a method for producing an airgel blanket.

In the case of the airgel blanket manufacturing method according to the present invention, a large amount of organic solvent and an expensive surface modifier are used, and the process is complicated and requires a long process time, so that the surface modification step that hinders economy and productivity can be omitted. In addition, accordingly, energy consumption can be reduced, and since the above step is omitted, a surface modification supply facility is not required, and thus a simplified manufacturing facility can be used.

In addition, in the case of the method of manufacturing an airgel blanket according to the present invention, it is possible to dry in a normal pressure drying method as well as supercritical drying.

In addition, in the case of the method for manufacturing an airgel blanket according to the present invention, by rotating the substrate for blanket impregnated with the sol catalyzed in the gelling process to perform gelation, the manufacturing time can be greatly reduced, and the thickness of the airgel blanket And the length does not affect the manufacturing time, it is possible to simplify the manufacturing equipment. In particular, in the present invention, when the thickness of the blanket substrate is thin and the length is long (thin grade), the above-described effect is further maximized, and in this case, there is an advantage in that productivity can be greatly increased.

In addition, in the case of the airgel blanket manufacturing method according to the present invention, by rotating the blanket substrate impregnated with the catalyzed sol, the airgel can be uniformly formed in the blanket substrate, thereby forming in the blanket substrate. The uniformity of the airgel can be further improved.

The following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the contents of the present invention, so that the present invention is limited to the matters described in such drawings. It is limited and should not be interpreted.

1 is a perspective view showing an airgel blanket manufacturing apparatus according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail to aid understanding of the present invention.

Terms and words used in the description and claims of the present invention should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

The present invention provides a method for manufacturing an airgel blanket.

A method for manufacturing an airgel blanket according to an embodiment of the present invention comprises the steps of: 1) introducing the catalyzed sol and a blanket substrate into a reaction vessel, and impregnating the catalyst with the blanket substrate with the catalyzed sol; And 2) rotating and gelling a substrate for a blanket impregnated with the catalyzed sol, wherein the catalyzed sol includes a silica precursor composition, and the silica precursor composition includes a silicate and tetrahydrophobic group. Including an alkyl silicate, the molar ratio of the silicate including the hydrophobic group and the tetraalkyl silicate may be from 60:40 to 98:2.

Hereinafter, the method of manufacturing the airgel blanket of the present invention will be described in detail for each step.

The step 1) according to an embodiment of the present invention is a step of preparing to form an airgel blanket, by impregnating the catalyzed sol into a substrate for the blanket, thereby preparing a catalyzed sol and preparing the prepared catalyzed sol. And impregnating the sol catalyzed into the blanket substrate by introducing the blanket substrate into the reaction vessel.

The term "impregnation" as used in the present invention may be achieved by introducing a catalyzed sol having fluidity into the substrate for blanket, and may refer to the penetration of the catalyzed sol into pores inside the substrate for blanket.

In addition, if the step 1) according to an embodiment of the present invention is to add the blanket substrate and the catalyzed sol to the reaction vessel, the order of the addition is not particularly limited. Specifically, the step 1) is a method of introducing a substrate for blanket into a reaction vessel and then introducing a catalyzed sol, a method of introducing a substrate for blanket after introducing the catalyzed sol into a reaction vessel, and catalyzing a catalyst into the reaction vessel. It may be introduced in any one of the methods of injecting the substrate for the blanket while injecting the sol. Among these, it may be more preferable to introduce the catalyst sol after the blanket substrate is added in view of more uniform impregnation. Specifically, when the blanket substrate is first introduced, a more uniform impregnation may be induced because the blanket substrate can be rotated when the catalyzed sol is introduced.

According to an embodiment of the present invention, the impregnation in step 1) may be performed while the blanket substrate is rotated as described above. When impregnation is performed while rotating the blanket substrate, the sol catalyzed uniformly contacts all surfaces of the blanket substrate to induce uniform impregnation, which is more preferable.

In the present invention, the catalyzed sol may be prepared by mixing a sol and a base catalyst, and the base catalyst serves to promote gelation in step 2) by increasing the pH of the sol.

In this case, the sol is not limited as long as it is a material capable of forming a porous gel through a sol-gel reaction, and specifically, may include an inorganic sol, an organic sol, or a combination thereof. Inorganic sols may include zirconia, yttrium oxide, hafnia, alumina, titania, ceria, silica, magnesium oxide, calcium oxide, magnesium fluoride, calcium fluoride, and combinations thereof, and the organic sol is polyacrylate, Polyolefin, polystyrene, polyacrylonitrile, polyurethane, polyimide, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehyde, resorcinol formaldehyde, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycylate Anurates, polyacrylamides, various epoxies, agar, agarose, and combinations thereof. In addition, in terms of securing excellent miscibility with the substrate for a blanket, further improving porosity when formed into a gel, and manufacturing an aerogel blanket having low thermal conductivity, preferably the sol may be a silica sol.

The sol according to an embodiment of the present invention includes a sol precursor, water, and an organic solvent, and may be prepared by mixing a sol precursor, water, and an organic solvent. When the catalyzed sol according to an embodiment of the present invention is a catalyzed silica sol, the silica sol catalyzed in step 1) may be prepared by mixing a silica sol and a base catalyst, wherein the silica sol Silver may be prepared by mixing a silica precursor composition, water, and an organic solvent. In addition, the silica sol may be hydrolyzed at a low pH to facilitate gelation, and in this case, an acid catalyst may be used to lower the pH.

The silica precursor composition usable for preparing the silica sol may include a silicon-containing alkoxide-based compound, and specifically may include a silicate containing a hydrophobic group and a tetraalkyl silicate.

According to an embodiment of the present invention, the silicate containing the hydrophobic group is for imparting hydrophobicity to the airgel without a surface modification step during the manufacture of the airgel, methyltriethoxysilane (MTES), trimethylethoxysilane (TMES), It may be one or more selected from the group consisting of trimethylsilanol (TMS), methyltrimethoxysilane (MTMS), dimethyldiethoxysilane (DMDEOS), ethyltriethoxysilane (ETES), and phenyltriethoxysilane (PTES). have. In the case of including a silicate containing a hydrophobic group in the silica precursor composition as described above, it is possible to omit the surface modification step, and accordingly, a regeneration process is unnecessary when the solvent is recycled, and the hydrophobic group can be evenly introduced from the inside to the outside of the aerogel. Therefore, hydrophobicity is maximized, and because of this, water having a large surface tension can be easily pushed out, allowing normal pressure drying in the subsequent drying step.

According to an embodiment of the present invention, the tetraalkyl silicate is for reinforcing the strength of the airgel and securing thermal insulation performance, and includes tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate; TEOS), tetrapropyl orthosilicate, tetraisopropyl orthosilicate, tetrabutyl orthosilicate, tetra secondary butyl orthosilicate, tetrater Tetra-tertiary butyl orthosilicate, tetrahexyl orthosilicate, tetracyclohexyl orthosilicate, tetradodecyl orthosilicate, etc. have. Among these, more specifically, the silica precursor according to an embodiment of the present invention may be tetraethyl orthosilicate (TEOS).

According to an embodiment of the present invention, the molar ratio of the silicate containing the hydrophobic group and the tetraalkyl silicate in the silica precursor composition may be 60:40 to 98:2, and the strength of the aerogel during supercritical drying within this range And it is possible to maximize the thermal insulation performance. In addition, in the case of drying under atmospheric pressure, the molar ratio of the silicate containing the hydrophobic group and the tetraalkyl silicate in the silica precursor composition may be 85:15 to 98:2, or 90:10 to 98:2, and this range While securing the strength and heat insulation performance of the airgel inside with high efficiency, it is possible to prevent the occurrence of shrinkage during normal pressure drying, thereby preventing the heat insulation performance from deteriorating.

_{The silica precursor composition may be used in an amount such that the content of silica (SiO 2} ) contained in the silica sol is 3% by weight to 30% by weight, 5% by weight to 20% by weight, or 6% by weight to 12% by weight. . Within this range, the content of the silica airgel in the final manufactured blanket can be sufficiently secured, so that the desired level of thermal insulation effect can be expected, and the formation of excessive silica aerogels prevents the mechanical properties of the blanket, especially the flexibility, from deteriorating. Can be prevented.

In addition, the organic solvent that can be used for the preparation of the sol of the present invention can be used without limitation as long as it has excellent compatibility with a sol precursor and water, and specifically, a polar organic solvent may be used, and more specifically, alcohol is used. It may be to use. Here, the alcohol is specifically a monohydric alcohol such as methanol, ethanol, isopropanol, butanol, and the like; Alternatively, it may be a polyhydric alcohol such as glycerol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and sorbitol, and any one or a mixture of two or more of them may be used. Among these, in consideration of miscibility with water and an airgel to be produced in the future, it may be a monohydric alcohol having 1 to 6 carbon atoms such as methanol, ethanol, isopropanol, butanol, and the like. The organic solvent as described above may be used in an appropriate amount in consideration of the content of the finally produced airgel.

The silica sol according to an embodiment of the present invention may contain a silica precursor composition and water in a molar ratio of 1:10 to 1:1. In addition, the silica precursor composition and the organic solvent may be included in a weight ratio of 1:2 to 1:9, and preferably may be included in a weight ratio of 1:2 to 1:6. When the silica precursor composition satisfies the molar ratio or weight ratio of water and organic solvents, the yield of airgel production may be further increased, and thus there is an improvement effect in terms of thermal insulation performance.

In addition, the acid catalyst that may be further included in the sol according to an embodiment of the present invention can be used without limitation as long as the acid catalyst has a pH of 3 or less, and hydrochloric acid, nitric acid, or sulfuric acid may be used as an example. In this case, the acid catalyst may be added in an amount such that the pH of the sol is 3 or less, and may be added in the form of an aqueous solution dissolved in an aqueous medium.

In addition, the base catalyst usable in the catalyzed sol according to an embodiment of the present invention includes inorganic bases such as sodium hydroxide and potassium hydroxide; Or an organic base such as ammonium hydroxide. Specifically, sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH) ₂ ), ammonia (NH ₃ ), ammonium hydroxide (NH ₄ OH; aqueous ammonia), tetramethylammonium hydroxide (TMAH), tetra Ethyl ammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), methylamine, ethylamine, isopropylamine, monoisopropylamine, diethylamine, diiso Propylamine, dibutylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, choline, monoethanolamine, diethanolamine, 2-aminoethanol, 2-(ethylamino)ethanol, 2-(methyl Amino) ethanol, N-methyl diethanolamine, dimethylaminoethanol, diethylaminoethanol, nitrilotriethanol, 2-(2-aminoethoxy)ethanol, 1-amino-2-propanol, triethanolamine, monopropanolamine, It may be one or more selected from the group consisting of dibutanolamine and pyridine, preferably sodium hydroxide, ammonia, ammonium hydroxide, or a mixture thereof.

The base catalyst may be included in an amount such that the pH of the sol is 7 to 11. If the pH of the sol is out of the above range, gelation in step 2) to be described later is not easy, or the gelation rate is too slow, and thus fairness may be lowered. In addition, since the base may be precipitated when introduced into a solid phase, it may be preferably added in the form of an aqueous medium or a solution diluted with the above-described organic solvent. In this case, the dilution ratio of the base catalyst and the organic solvent, specifically alcohol, may be 1:4 to 1:100 on a volume basis.

According to an embodiment of the present invention, additives may be further added to the catalyzed sol as needed, and in this case, all known additives that may be added when preparing an aerogel may be applied, for example, an opacifying agent. And additives such as flame retardants may be used.

The blanket substrate may be introduced in a suitable shape that is easy to input according to the shape of the reaction vessel, and specifically, a blanket substrate wound in a roll shape on a bobbin to facilitate rotation in step 2) to be described later It may be added to the reaction vessel. In this case, the bobbin may be a shaft capable of rotating the blanket substrate, and any one that can wind the blanket substrate may be applied without limitation. As an example, it may be to use a polygonal cylindrical column, preferably a cylindrical column having a size that can fit inside the reaction vessel. In addition, according to an embodiment of the present invention, the bobbin may include a winding rod capable of winding a blanket substrate in a roll form, and a support plate supporting a side portion so that the blanket substrate wound around the winding rod does not separate during rotation. . At this time, it is preferable that there are a number of hollows in the winding rod so that the catalyzed sol is easily impregnated inside the blanket substrate. On the other hand, the support plate may use a mesh type or may include a plurality of hollows so that the sol catalyzed to the side of the blanket substrate can flow. The material of the bobbin may be any material having sufficient strength to support the blanket, and specifically stainless steel, PE, PP, Teflon, etc. may be used.

After winding the substrate for a blanket on the bobbin, it may be placed in a reaction vessel and fixed. Here, the bobbin can be fixed at any position of the reaction vessel, but a lot of the blanket substrate is added in the reaction vessel of the same volume, and thus, in terms of increasing production efficiency, the bobbin is preferably fixed to the center of the reaction vessel. Can be. In addition, it may be to position the bobbin so that the long axis of the bobbin and the long axis of the reaction vessel are parallel to each other.

In addition, the substrate for a blanket according to an embodiment of the present invention may be specifically a porous substrate in terms of improving the thermal insulation properties of the airgel blanket. When a porous blanket substrate is used, the catalyzed sol easily penetrates into the substrate, and thus the airgel blanket formed uniformly forms the airgel inside the blanket substrate, so that the manufactured airgel blanket can have excellent thermal insulation properties.

The blanket substrate that can be used according to an embodiment of the present invention may be a film, sheet, net, fiber, foam, nonwoven fabric, or a laminate of two or more layers thereof. In addition, depending on the use, the surface roughness may be formed or patterned on the surface. More specifically, the blanket substrate may be a fiber capable of further improving thermal insulation performance by including spaces or voids in which the airgel can be easily inserted into the blanket substrate. In addition, it may be desirable that the blanket substrate has a low thermal conductivity.

Specifically, the blanket substrate is polyamide, polybenzimidazole, polyaramid, acrylic resin, phenolic resin, polyester, polyetheretherketone (PEEK), polyolefin (e.g., polyethylene, polypropylene or a copolymer thereof Etc.), cellulose, carbon, cotton, wool, hemp, non-woven fabric, glass fiber or ceramic wool, etc., and more specifically, in the present invention, the substrate for the blanket may be glass fiber (glass felt, glass fiber).

According to an embodiment of the present invention, the reaction vessel may be a reaction vessel for performing gelation, and if a vessel forming a space so that the blanket substrate impregnated with the catalyzed sol can rotate, a polygonal cylinder, a cylindrical shape, etc. Any shape of the container can be used, but it is preferable to have a cylindrical shape in terms of facilitating the introduction of the blanket substrate wound in a roll form, and the rotation of the blanket substrate impregnated with the catalyzed sol during the gelation reaction. A reaction vessel can be used.

When the sol catalyzed in step 1) is added, the blanket base material may be lightly pressed so as to be sufficiently impregnated in order to improve the bonding between the blanket base material and the catalyzed sol. After that, by pressing the substrate for the blanket to a predetermined thickness with a constant pressure to remove excess sol, it is also possible to reduce the drying time. In another embodiment, when the catalyst is added to the reaction vessel, the blanket substrate is sufficiently impregnated and the remaining sol may be recovered when the liquid level in the reaction vessel is no longer changed. Silver may be recovered by opening a drain valve connected to the reaction vessel.

In addition, the catalyzed sol and the substrate for the blanket may each be added in an amount of 1 to 100% of the volume of the reaction vessel, specifically, the inner volume of the reaction vessel, shortening the gelation time in step 3) and the inside of the blanket substrate. In terms of uniformly forming the airgel in the reaction vessel, an amount of preferably 1 to 60% of the volume of the reaction vessel, more preferably 10 to 60%, and even more preferably 30 to 60% of the volume of the reaction vessel is respectively added. I can.

According to an embodiment of the present invention, the catalyzed sol may be added in an amount of 80 to 120%, preferably 90 to 110%, based on the volume of the blanket substrate. In addition, preferably, the amount of the blanket substrate and the catalyzed sol may be one that satisfies the above-mentioned ratio of each other under the condition of satisfying the amount of injection compared to the reaction vessel. When the catalyzed sol satisfies the input ratio (input amount) to the volume of the blanket substrate, the aerogel blanket produced by impregnating the catalyst sol more evenly into the blanket substrate may have more uniform physical properties, and the catalyzed sol Since all of this blanket substrate can be impregnated, loss of raw materials can be prevented and the problem of gelation of the catalyzed sol alone can be prevented.

Step 2) according to an embodiment of the present invention is for preparing a wet gel blanket composite (wet gel blanket), and may be performed by rotating and gelling a blanket substrate impregnated with a catalyzed sol.

Any method and apparatus can be used as long as the catalyst for the blanket substrate impregnated with the catalyzed sol is rotated while gelling in the reaction vessel. Specifically, the blanket substrate is wound around a bobbin in step 1). In the case of input and fixation, the substrate for blanket impregnated with the catalyzed sol exists in the reaction vessel while being wound around the bobbin, so that the substrate for blanket impregnated with the catalyzed sol is rotated by rotating the bobbin. I can.

In the present invention, the gelation may be the formation of a network structure from a catalyzed sol, and the network structure is a specific polygon having one or more kinds of atomic arrangement. It may represent a structure in the form of a flat net or a structure that forms a three-dimensional skeleton structure by sharing the vertices, edges, and faces of a specific polyhedron.

According to an embodiment of the present invention, after sealing a reaction vessel in which the catalyzed sol and a substrate for a blanket are added, the gelling reaction may be performed. In addition, according to an embodiment of the present invention, the long axis may be disposed in a transverse direction, that is, in a horizontal direction to rotate. If the reaction vessel (body) is a cylindrical reaction vessel, the cylindrical reaction vessel may be laid down and rotated. That is, the rotation axis of the reaction vessel of the present invention may be in a horizontal direction, but is not limited thereto.

According to an embodiment of the present invention, if it is an apparatus for manufacturing an airgel blanket including the reaction vessel (body) and capable of rotating the blanket substrate impregnated with the catalyzed sol present in the reaction vessel, the type is not limited. However, any known device may be used as long as it is a device capable of rotating. Specifically, any known device may be used as long as the position of the bobbin can be fixed to the reaction vessel and the position of the bobbin is rotated. An example of an apparatus for manufacturing an airgel blanket applicable in the present invention will be described later.

In addition, according to an embodiment of the present invention, after completing step 1), step 2) may be initiated to sequentially perform step 1) and step 2).

According to another embodiment of the present invention, the step 2) may be initiated and performed before step 1) is completed. In this way, when step 2) is performed before step 1) is completed, Until the gelation is completed, specifically, the catalyst may be all injected into the reaction vessel until the gelation is completed.

According to an embodiment of the present invention, the rotational speed in step 2) is applicable without limitation in terms of rotational speed that enables uniform formation of the airgel in the blanket, and for example, 1 rpm to 300 rpm, preferably 5 It may be to perform gelation while rotating at a rotation speed of rpm to 150 rpm, 5 rpm to 100 rpm, more preferably 10 rpm to 30 rpm. If the reaction vessel satisfies the above range of rotational speed, the sol in the blanket substrate may be evenly impregnated, so that the aerogel is formed more evenly during gelation, and thus, very uniform thermal conductivity can be secured throughout the airgel blanket and the reaction There is an advantage of increasing the safety of the airgel blanket manufacturing process by increasing the stability of the container and the device that rotates it.

In the present invention, as an aerogel blanket is manufactured by putting both the catalytic sol and the blanket substrate in the reaction vessel and gelling it, unlike the conventional roll-to-roll method, a moving element such as a conveyor belt is not separately required. There is an advantage that can save a lot of money. In addition, as in the roll-to-roll method, when a blanket substrate is placed on a moving element and a catalyzed sol is applied to the blanket substrate to gel while continuing to move the moving element, gelation is performed simultaneously on the entire blanket substrate. The gelling process according to an embodiment of the present invention, even if a blanket substrate having the same thickness and length is used because gelling is inevitable sequentially according to the passage of time while continuously supplying the blanket substrate and the catalyzed sol. A problem occurs that takes significantly longer than that. In particular, the longer the blanket substrate is, the more pronounced the problem of lengthening the gelling process time in order to achieve sufficient gelation throughout the blanket substrate.According to an embodiment of the present invention, gelation of the sol is simultaneously performed in the entire blanket substrate. Because of this, the manufacturing time can be remarkably reduced, and since the length and thickness of the blanket substrate do not affect the gelation time, even if a long blanket substrate is used, the manufacturing time can be significantly reduced, thereby maximizing process efficiency.

In addition, according to an embodiment of the present invention, since centrifugal force and centripetal force act by performing gelation while rotating the reaction vessel, the reaction vessel is not rotated, or the airgel is more uniformly dispersed compared to the roll-to-roll method of gelling on a moving element. Since the airgel blanket can be manufactured, the thickness of the airgel blanket to be manufactured is the same as or extremely similar to the thickness of the substrate for the blanket, and there is an effect of excellent thermal insulation properties.

Additionally, in the manufacturing method according to an embodiment of the present invention, the wet gel blanket composite is left at an appropriate temperature to complete the chemical change, and the aging step may be performed, and the aging step further enhances the formed network structure. Since it can be formed firmly, the mechanical stability of the airgel blanket of the present invention can be enhanced.

The aging step of the present invention may be carried out by leaving the wet gel blanket complex itself at an appropriate temperature, and as another example, in the presence of the wet gel blanket complex, sodium hydroxide (NaOH), potassium hydroxide (KOH), and ammonium hydroxide (NH ₄ OH), triethylamine, pyridine, etc. can be carried out by adding a solution obtained by diluting a basic catalyst such as 1 to 10% concentration in an organic solvent. In this case, by inducing Si-O-Si bonding in the airgel to the maximum, the network structure of the silica gel is made more solid, and thus the maintenance of the pore structure in the fast drying process to be performed later is more easily effective. In this case, the organic solvent may be the aforementioned alcohol (polar organic solvent), and specifically, may include ethanol.

In addition, the aging step should be carried out at an appropriate temperature range for reinforcing the optimal pore structure. The aging step of the present invention is performed by allowing it to stand at a temperature of 30 to 70° C. for 1 to 20 hours, regardless of whether or not a basic catalyst is added. Can be. If the aging temperature is less than 30 ℃, there may be a problem that the aging time is too long, leading to an increase in the overall process time, resulting in a decrease in productivity. If the aging temperature is more than 70 ℃, it is out of the boiling point of ethanol, so the solvent by evaporation There may be a problem of increasing the loss of raw materials and increasing the cost of raw materials.

In addition, according to an embodiment of the present invention, the aging step may be performed in a separate reaction vessel after recovering the gelled silica wet gel blanket, or may be performed inside the reaction vessel in which gelation was performed, In terms of process efficiency and simplification of equipment, the aging step may be preferably performed in the reaction vessel in which gelation has been performed. In addition, when performing the aging step in the reaction vessel in which gelation has been performed, the wet gel blanket composite prepared in step 3) may be rotated, and when aging is performed while rotating, the aging solvent may penetrate better. And, since the dispersion can be made better in the wet gel blanket composite after penetration, there is an advantage that the aging efficiency is greatly improved.

In addition, the manufacturing method according to an embodiment of the present invention may perform a solvent replacement step prior to the drying step for manufacturing an airgel blanket from the wet gel blanket composite. The wet gel of the wet gel blanket composite has pores filled with a solvent including water and/or an organic solvent, and when the solvent is removed by performing the step of drying the wet gel blanket composite, the liquid solvent vaporizes into a gas phase. Shrinkage and cracking of the pore structure occur due to the surface tension of the solvent at the gas/liquid interface. As a result, a decrease in specific surface area and a change in pore structure in the final produced silica airgel occur. Therefore, in order to maintain the pore structure of the wet gel, it is necessary to minimize the surface tension of the solvent, and for this, it is necessary to replace water having high surface tension with a solvent having low surface tension.

As the substituted solvent, a solvent that can be mixed with silica gel after gelation may be a hydrophilic polar organic solvent, and a specific example may be an alcohol. Specifically, the alcohol is a monohydric alcohol such as methanol, ethanol, isopropanol, butanol; Alternatively, it may be a polyhydric alcohol such as glycerol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and sorbitol, and any one or a mixture of two or more of them may be used. Among these, in consideration of miscibility with water and a hydrophobic airgel, it may be a monohydric alcohol having 1 to 6 carbon atoms such as methanol, ethanol, isopropanol, butanol, and the like.

The manufacturing method according to an embodiment of the present invention may perform a step of drying to manufacture an airgel blanket from the wet gel blanket composite.

The drying step according to an embodiment of the present invention may be performed through a process of removing the solvent while maintaining the pore structure of the aged gel, and the drying step may be performed by a supercritical drying process or an atmospheric drying process. .

The supercritical drying process may be performed using supercritical carbon dioxide. Carbon dioxide (CO ₂ ) is in a gaseous state at room temperature and pressure, but when it exceeds the limit of a certain temperature and high pressure called the supercritical point, the evaporation process does not occur, and it becomes a critical state in which gas and liquid cannot be distinguished. Carbon dioxide in the state is called supercritical carbon dioxide. Although supercritical carbon dioxide has a molecular density close to that of a liquid, its viscosity is low, it has a property close to that of a gas, has a fast diffusion, high thermal conductivity, high drying efficiency, and can shorten a drying process time.

Specifically, in the supercritical drying process, a wet gel blanket that has been aged in a supercritical drying reactor is placed, and then a liquid CO ₂ is filled and the alcohol solvent in the wet gel is replaced _{with CO 2.} After that, after raising the temperature to 40 to 70° C. at a rate of constant temperature increase, specifically, 0.1° C./min to 1° C./min, a pressure equal to or higher than the pressure at which carbon dioxide becomes a supercritical state, specifically 100 bar to 150 bar By maintaining the pressure of carbon dioxide in a supercritical state, it is maintained for a certain period of time, specifically 20 minutes to 1 hour. In general, carbon dioxide becomes supercritical at a temperature of 31 °C and a pressure of 73.8 bar. Carbon dioxide is maintained at a constant temperature and pressure at a supercritical state for 2 to 12 hours, more specifically for 2 to 6 hours, and then the pressure is gradually removed to complete the supercritical drying process to manufacture an airgel blanket. I can.

In addition, in the case of the normal pressure drying process, it may be performed according to conventional methods such as hot air drying and IR drying under a temperature of 70 to 200° C. and atmospheric pressure (1±0.3 atm).

As a result of the drying process as described above, a blanket including a porous airgel having nano-sized pores may be manufactured. In particular, the silica airgel according to an embodiment of the present invention has excellent physical properties with high hydrophobicity, particularly low density and high porosity, and the silica airgel-containing blanket including the same has low thermal conductivity and excellent mechanical flexibility.

In addition, a pressing process to adjust the thickness before or after the drying process and to make the internal structure and surface shape of the blanket uniform, a molding process to have an appropriate shape or morphology according to the use, or a lamination process of laminating a separate functional layer And the like may be further performed.

The present invention provides an airgel blanket manufacturing apparatus for carrying out the above airgel blanket manufacturing method.

The airgel blanket manufacturing apparatus according to an embodiment of the present invention is provided with a bobbin 100 on which a blanket is wound, and a gelation tank 210 accommodating the bobbin 100, as shown in FIG. 1. The main body 200, a driving member 300 for rotating the bobbin 100 accommodated in the gelling tank 210, and a catalyzed sol supply member 400 for injecting the catalyzed sol into the gelling tank 210 , An aging member (not shown) for injecting an aging solution into the gelling tank 210, and a drying member (not shown) for drying the blanket by increasing the temperature of the gelling tank 210.

Here, the blanket may mean a blanket substrate before the catalyzed sol is introduced, a blanket substrate impregnated with the catalyzed sol, and/or a wet gel blanket after gelation. It can be interpreted appropriately according to.

The bobbin is for winding the blanket in a roll-shape, and includes a winding rod on which the blanket is wound in a roll shape, and a support plate coupled to both ends of the winding rod and supporting the sides of the blanket wound on the winding rod.

The winding rod has a cylindrical shape in which a hollow penetrated in the longitudinal direction is formed, and a blanket in the form of a long sheet is wound in a roll shape on an outer circumferential surface.

On the other hand, the outside of the blanket wound on the winding rod can be quickly impregnated with the catalyzed sol, so that the catalyst can be stably gelled, but the inside of the blanket has a problem that it takes a lot of time to impregnate the catalyst. To prevent this, the outer circumferential surface of the winding rod includes a plurality of connection holes connected to the hollow.

That is, the winding rod has a hollow inside so as to introduce the catalyzed sol injected into the gelation tank, and the catalyzed sol introduced into the hollow flows out of the winding rod and impregnates the inside of the blanket wound on the winding rod. A plurality of connection holes so as to be formed are formed. Accordingly, the outer and inner sides of the blanket can be gelled by simultaneously impregnating the catalyzed sol, and as a result, the time required for gelling of the blanket can be greatly shortened, and as a result, the entire blanket can be uniformly gelled. .

Meanwhile, the plurality of connection holes have a diameter of 3 to 5 mm, and are formed at regular intervals on the outer circumferential surface of the winding rod. Accordingly, the sol catalyzed uniformly can be supplied to the entire blanket wound on the outer circumferential surface of the winding rod, and accordingly, the entire inner side of the blanket can be uniformly gelled.

The support plate supports the blanket wound around the winding rod so that it is not wound irregularly, has a disk shape, is coupled to both ends of the winding rod, and supports side portions of the blanket wound around the winding rod.

Meanwhile, the support plate includes a fastening groove to which an end of the winding rod is coupled, and a fastening hole formed on a bottom surface of the fastening groove. That is, the support plate may be coupled to the end of the winding rod through the fastening groove.

On the other hand, the support plate has a plurality of open holes, and the plurality of open holes can introduce the catalyzed sol to the side of the blanket wound on the winding rod, thereby stably gelling the side of the blanket.

Therefore, the bobbin includes a winding rod and a support plate, and accordingly, the blanket can be wound in a roll form.

The body is provided with a gelling tank accommodating a bobbin, and includes a gelling tank and a first installation member 220 on which the gelling tank is installed.

The gelling tank is for gelling the blanket contained in the bobbin, and includes a gelling chamber provided inside and accommodating the bobbin, an outlet provided at the outer lower end and connected to the gelling chamber, and an inlet provided at the outer upper end and connected to the gelling chamber do.

In particular, the gelation chamber of the gelation tank has a'U'-shaped cross-sectional shape with a curvature corresponding to that of the blanket wound on the winding rod and the upper part of the gelation chamber opened by the cover. Accordingly, when silica sol flows into the gelation chamber, The contact force between the blanket and the blanket can be increased, and as a result, the gelation of the blanket can be increased.

On the other hand, the gelation tank is provided on both walls of the gelation chamber, and is coupled to both ends of the bobbin and includes a rotating member for rotatably installing the bobbin in the gelation chamber.

The rotating member is rotatably installed in through-holes formed on both walls of the gelling chamber, and ends of the bobbin accommodated in the gelling chamber are installed to transmit power.

For example, a straight coupling protrusion is formed on one surface of the rotating member, and a straight coupling groove to which the coupling protrusion is coupled is formed at an end of the bobbin. That is, the bobbin can be rotated in the same direction when the rotating member is rotated through the coupling of the coupling protrusion and the coupling groove. As a result, the bobbin can be installed rotatably inside the gelation tank.

On the other hand, the main body further includes a second installation member 230 in which a catalyzed sol supply member is installed, and the second installation member is installed on the bottom piece 231 and on the top of the bottom piece to supply the catalyzed sol. It includes an installation table 232 installed so that the member is positioned higher than the gelation tank, and a staircase 233 installed at one end of the bottom piece.

Meanwhile, the gelation tank includes a rotation handle that rotates the bobbin while being coupled with the other rotation member provided in the gelation tank, and the rotation handle may manually rotate the bobbin from the outside.

Meanwhile, a maturing member and a drying member are further installed on the mounting table of the second mounting member.

The driving member is for rotating the bobbin accommodated in the gelling tank, and is connected to the other rotating member provided in the gelling tank so as to transmit power. That is, when the driving member rotates the rotating member, the bobbin accommodated in the gelling tank can be rotated in conjunction with the rotating member.

The catalyzed sol supply member is for gelling the blanket by impregnating the blanket wound on the bobbin by injecting silica sol into the gelation tank.It is installed on the mounting table, and the catalyzed sol is gelled through the inlet of the gelling tank. Supply to the Japanese style room.

The aging member is for aging the blanket wound on the bobbin by injecting the aging solution into the gelation tank, and is installed on the mounting table, and supplies the aging solution to the gelation chamber through the inlet of the gelation tank.

The drying member is for drying the blanket wound on the bobbin by supplying high-temperature hot air to the gelling tank, and is installed on the mounting table and drying the blanket accommodated in the gelling tank by increasing the temperature of the gelling tank.

Therefore, the airgel blanket manufacturing apparatus according to an embodiment of the present invention can greatly shorten the manufacturing time of the airgel blanket, greatly increase the productivity of the airgel blanket, and as a result, mass-produce the airgel blanket.

In particular, the airgel blanket manufacturing apparatus according to an embodiment of the present invention can induce stable gelation regardless of the thickness and length of the blanket by rotating the blanket, and since the bobbin rotates, the entire blanket wound around the bobbin is uniformly Gelation is possible, and the shape of the gelation tank is not limited because only the bobbin rotates without rotating the gelation tank. In addition, as the gelation chamber of the gelation tank is formed in a'U' cross-sectional shape, the blanket wound around the bobbin can be gelled more effectively.

In addition, according to an embodiment of the present invention, the airgel blanket manufacturing apparatus includes a bobbin on which a blanket is wound, and the bobbin may include a winding rod and a support plate. Here, the outer circumferential surface of the winding rod may include a fixing clip that is inserted and fixed at the winding point of the blanket.

That is, the fixing clip has a pin shape having an elastic restoring force, one end is fixed to the outer circumferential surface of the winding rod and the other end is elastically supported on the outer circumferential surface of the winding rod. Accordingly, when the starting point of the blanket is inserted between the other end of the fixing clip and the winding rod, the blanket can be fixed to the starting point of the winding rod by the elastic force of the fixing clip, and as a result, the blanket can be easily wound on the outer circumferential surface of the winding rod.

The present invention provides an airgel blanket manufactured from the method for manufacturing an airgel blanket. The airgel blanket has low thermal conductivity and low moisture impregnation rate. In this case, the airgel blanket is characterized in that the thermal conductivity in the blanket is 21.0 mW/mK or less. In addition, the airgel blanket may have a moisture impregnation rate of 2.0% by weight or less or 1.5% by weight or less in the blanket. The thermal conductivity is a characteristic that can appear all in an arbitrarily cut airgel blanket, specifically, it may be a thermal conductivity value measured in an area ^{of 0.01 m 2} to 10.0 m ² , and more specifically, an area of 0.36 m ² to 5.0 m ^2. .

For example, the thermal conductivity of the airgel blanket may be obtained by obtaining a sample having a certain size in the airgel blanket, and measuring the thermal conductivity at room temperature (23±5°C) for each sample using the HFM 436 Lambda equipment of NETZSCH have.

In addition, according to an embodiment of the present invention, the airgel blanket includes an airgel and a substrate for a blanket, and specifically, the airgel may be formed inside and on the surface of the blanket substrate, for example, on the inside and the surface of the blanket substrate. It may be that a large amount of airgel particles are formed evenly.

Accordingly, the airgel blanket of the present invention can be usefully used as a thermal insulation material, a thermal insulation material, or a non-combustible material, such as an aircraft, ship, automobile, building structure, as well as a plant facility for thermal insulation such as pipes or industrial furnaces of various industrial facilities.

Example

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

Example 1

<Production of catalyzed sol>

A silica precursor composition was prepared by mixing methyltetraethoxysilane (MTES) and tetraethylorthosilicate (TEOS) at a molar ratio of 95:5. The silica precursor composition and water were mixed at a molar ratio of 1:10, and a silica precursor composition and ethanol having a weight ratio of 1:2 were added to prepare a silica sol. Hydrochloric acid was added so that the silica sol had a pH of 3 or less to accelerate hydrolysis. A silica sol was prepared _{by mixing 0.2 parts by weight of TiO 2 as} an opacifying agent and 0.2 parts by weight of a flame retardant Ultracarb (LKAB) based on 100 parts by weight of the silica sol and stirring for 30 minutes. Separately, a 1 vol% ammonia ethanol solution (base catalyst solution) was prepared. The silica sol and the base catalyst solution were mixed in a volume ratio of 9:1 to prepare a catalyzed sol.

<Manufacture of wet gel blanket>

A bobbin wound with 10T (10 mm) glass fiber was fixed to the reaction vessel. The prepared catalyzed sol was put into a reaction vessel, and the bobbin wound around the glass fiber was rotated to perform gelation. At this time, the rate of addition of the catalyzed sol was adjusted so that all of the catalyzed sol could be added before the gelation was completed. When the fiber was sufficiently impregnated and the liquid level in the reaction vessel no longer changed, the remaining sol was recovered by opening the drain valve coupled to the reaction vessel. After 60 minutes, gelation was completed, and aged at a temperature of 60° C. for 20 hours. When the aging was completed, ethanol was added to the reaction vessel at a temperature of 60° C. to replace the solvent.

<Drying process>

Thereafter, the wet gel blanket was placed in a convection oven, and then dried at 150° C. for 2 to 5 hours under normal pressure to completely remove the solvent and moisture to prepare a hydrophobic silica airgel blanket.

Example 2

In Example 1, in the preparation of the catalyzed sol, except that the silica precursor composition was prepared by mixing methyltetraethoxysilane (MTES) and tetraethylorthosilicate (TEOS) at a molar ratio of 90:10. It was carried out in the same manner as in Example 1.

Example 3

In Example 1, except for preparing a silica precursor composition by mixing methyltetraethoxysilane (MTES) and tetraethylorthosilicate (TEOS) at a molar ratio of 98:2 when preparing the catalyzed sol. It was carried out in the same manner as in Example 1.

Example 4

In Example 1, during the drying process, the wet gel blanket was put into a supercritical extractor, CO ₂ was injected, the temperature in the extractor was raised to 50 °C over 1 hour, and supercritical drying was performed at 50 °C and 100 bar. Thereafter, the same as in Example 1, except that the hydrophobic silica airgel blanket having been completed supercritical drying was dried in an oven at 200° C. for 2 hours at atmospheric pressure to completely remove the solvent and moisture to prepare a hydrophobic silica airgel blanket. It was carried out by the method.

Example 5

In Example 2, during the drying process, the wet gel blanket was put into a supercritical extractor, CO ₂ was injected, the temperature in the extractor was raised to 50 °C over 1 hour, and supercritical drying was performed at 50 °C and 100 bar. Thereafter, the same as in Example 2, except that the hydrophobic silica airgel blanket having been completed supercritical drying was dried in an oven at 200° C. for 2 hours at atmospheric pressure to completely remove the solvent and moisture to prepare a hydrophobic silica airgel blanket. It was carried out by the method.

Example 6

In Example 3, during the drying process, the wet gel blanket was put into a supercritical extractor, CO ₂ was injected, the temperature in the extractor was raised to 50° C. over 1 hour, and supercritical drying was performed at 50° C. and 100 bar. Thereafter, the same as in Example 3, except that the hydrophobic silica airgel blanket having supercritical drying was completed in an oven at 200° C. for 2 hours under normal pressure to completely remove the solvent and moisture to prepare a hydrophobic silica airgel blanket. It was carried out by the method.

Example 7

In Example 1, when preparing the catalyzed sol, methylmethraethoxysilane (MTES) and tetraethylorthosilicate (TEOS) were mixed at a molar ratio of 60:40 instead of 95:5 to prepare a silica precursor composition. In the manufacturing and drying process, the wet gel blanket was put into a supercritical extractor, CO ₂ was injected, the temperature in the extractor was raised to 50° C. over 1 hour, and supercritical drying was performed at 50° C. and 100 bar, followed by supercritical drying. It was carried out in the same manner as in Example 1, except that the hydrophobic silica airgel blanket having completed critical drying was dried in an oven at 200°C for 2 hours at atmospheric pressure to completely remove the solvent and moisture to prepare a hydrophobic silica airgel blanket. I did.

Comparative Example 1

<Production of catalyzed sol>

A silica sol was prepared by mixing tetraethylorthosilicate (TEOS) and water at a molar ratio of 1:10, and adding TEOS and ethanol having a weight ratio of 1:2. Hydrochloric acid was added so that the silica sol had a pH of 3 or less to accelerate hydrolysis. A silica sol was prepared _{by mixing 0.2 parts by weight of TiO 2 as} an opacifying agent and 0.2 parts by weight of Ultracarb (LKAB) as a flame retardant based on 100 parts by weight of the silica sol and stirring for 30 minutes to prepare a silica sol. Base catalyst solution) was prepared. The silica sol and the base catalyst solution were mixed in a volume ratio of 9:1 to prepare a catalyzed sol.

<Manufacture of wet gel blanket>

A bobbin wound with 10T (10 mm) glass fiber was fixed to the reaction vessel. The prepared catalyzed sol was put into a reaction vessel, and the bobbin wound around the glass fiber was rotated to perform gelation. At this time, the rate of addition of the catalyzed sol was adjusted so that all of the catalyzed sol could be added before the gelation was completed. When the fiber was sufficiently impregnated and the liquid level in the reaction vessel no longer changed, the remaining sol was recovered by opening the drain valve coupled to the reaction vessel. After 30 minutes, when the gelation was completed, the aging solution was added to the reaction vessel, and the bobbin was rotated to proceed with aging. At this time, the aging solution was a 5 vol% ammonia ethanol diluted solution, and was aged for 20 hours at a temperature of 60°C. When the aging was completed, the drain valve was opened to recover the aging solution. Thereafter, the surface modification solution was added to the reaction vessel to perform surface modification while rotating the bobbin, and after completion, the surface modification solution was recovered. At this time, the surface modification solution was a 10 vol% of hexamethyldisilazane (HMDS) ethanol diluted solution, and an amount having the same volume ratio as that of the wet gel blanket composite was added. Surface modification (hydrophobicization) was performed at room temperature for 8 hours.

<Drying process>

Thereafter, the wet gel blanket was placed in a convection oven, and then dried at 150° C. for 2 to 5 hours under normal pressure to completely remove the solvent and moisture to prepare a hydrophobic silica airgel blanket.

Comparative Example 2

In Example 1, when preparing the catalyzed sol, methyltetraethoxysilane (MTES) and tetraethylorthosilicate (TEOS) were not mixed, except that methyltetraethoxysilane (MTES) was used alone. Was carried out in the same manner as in Example 1.

Comparative Example 3

In Example 1, when preparing the catalyzed sol, methyltetraethoxysilane (MTES) and tetraethylorthosilicate (TEOS) were not mixed, except that tetraethylorthosilicate (TEOS) was used alone. Was carried out in the same manner as in Example 1.

Comparative Example 4

In Comparative Example 1, during the drying process, the wet gel blanket was put into a supercritical extractor, CO ₂ was injected, the temperature in the extractor was raised to 50° C. over 1 hour, and supercritical drying was performed at 50° C. and 100 bar. Thereafter, the same as in Comparative Example 1, except that the hydrophobic silica airgel blanket having been completed supercritical drying was dried in an oven at 200° C. for 2 hours at atmospheric pressure to completely remove the solvent and moisture to prepare a hydrophobic silica airgel blanket. It was carried out by the method.

Comparative Example 5

In Comparative Example 2, during the drying process, the wet gel blanket was put into a supercritical extractor, CO ₂ was injected, the temperature in the extractor was raised to 50° C. over 1 hour, and supercritical drying was performed at 50° C. and 100 bar. Thereafter, the same as in Comparative Example 2, except that the hydrophobic silica airgel blanket having supercritical drying was completed in an oven at 200° C. for 2 hours at atmospheric pressure to completely remove the solvent and moisture to prepare a hydrophobic silica airgel blanket. It was carried out by the method.

Comparative Example 6

In Comparative Example 3, during the drying process, the wet gel blanket was put into a supercritical extractor, CO ₂ was injected, the temperature in the extractor was raised to 50° C. over 1 hour, and supercritical drying was performed at 50° C. and 100 bar. Thereafter, the same as in Comparative Example 3, except that the hydrophobic silica airgel blanket having been completed supercritical drying was dried in an oven at 200° C. for 2 hours at atmospheric pressure to completely remove the solvent and moisture to prepare a hydrophobic silica airgel blanket. It was carried out by the method.

Comparative Example 7

In Example 1, when manufacturing the wet gel blanket, it was carried out in the same manner as in Example 1, except that the following was carried out.

<Manufacture of wet gel blanket>

Using a roll-to-roll device equipped with a conveyor belt, the prepared catalyzed sol was cast and impregnated into 10T (10 mm) glass fiber, and gelation was performed. After the gelation was completed, it was aged for 20 hours at a temperature of 60°C. When the aging was completed, ethanol was added to the reaction vessel at a temperature of 60° C. to replace the solvent.

Comparative Example 8

In Example 2, when manufacturing the wet gel blanket, it was carried out in the same manner as in Example 2, except that the following was carried out.

<Manufacture of wet gel blanket>

Using a roll-to-roll device equipped with a conveyor belt, the prepared catalyzed sol was cast and impregnated into 10T (10 mm) glass fiber, and gelation was performed. After the gelation was completed, it was aged for 20 hours at a temperature of 60°C. When the aging was completed, ethanol was added to the reaction vessel at a temperature of 60° C. to replace the solvent.

Comparative Example 9

In Example 3, when manufacturing the wet gel blanket, it was carried out in the same manner as in Example 3, except that it was carried out as follows.

<Manufacture of wet gel blanket>

Using a roll-to-roll device equipped with a conveyor belt, the prepared catalyzed sol was cast and impregnated into 10T (10 mm) glass fiber, and gelation was performed. After the gelation was completed, it was aged for 20 hours at a temperature of 60°C. When the aging was completed, ethanol was added to the reaction vessel at a temperature of 60° C. to replace the solvent.

Experimental example

For the silica airgel blankets prepared in Examples 1 to 6 and Comparative Examples 1 to 9, thermal conductivity and moisture impregnation rate were measured as follows, and are shown in Tables 1 and 2, respectively.

* Room temperature thermal conductivity (mW/mK): In the silica airgel blanket prepared in each Example and Comparative Example, 5 samples having a size of 30 cm X 30 cm were prepared for each blanket, and HFM 436 Lambda of NETZSCH company for the sample The thermal conductivity was measured at room temperature (23±5° C.) using the equipment. At this time, five samples were obtained by cutting at regular intervals of 50 cm from the innermost side to the outermost side of the airgel blanket rolls prepared in each of the Examples and Comparative Examples. After measuring the thermal conductivity of each of the five samples, the values were compared to show the highest and lowest values of the thermal conductivity.

* Moisture impregnation rate (wt%): For the silica airgel blanket prepared in each Example and Comparative Example, a 100 mm x 100 mm size specimen was floated on distilled water at 21±2 °C, and a 6.4 mm mesh screen was placed on the specimen. ) Was raised and soaked up to 127 mm below the water surface and impregnated. After 15 minutes, the mesh screen was removed, and when the specimen floated, the specimen was picked up with a clamp and suspended vertically for 60 ± 5 seconds. After that, the weight before and after impregnation is measured, and the weight increase rate is checked, and it is expressed as the moisture impregnation rate. The lower the moisture impregnation rate, the higher the degree of hydrophobicity of the airgel blanket.

division		Example
		One	2	3	4	5	6	7
Silica precursor composition	(Kinds)	MTES:TEOS	MTES:TEOS	MTES:TEOS	MTES:TEOS	MTES:TEOS	MTES:TEOS	MTES:TEOS
	(Molar ratio)	95:5	90:10	98:2	95:5	90:10	98:2	60:40
Gelation step		rotation	rotation	rotation	rotation	rotation	rotation	rotation
Surface modification step		X	X	X	X	X	X	X
Drying step		Normal pressure	Normal pressure	Normal pressure	Supercritical	Supercritical	Supercritical	Supercritical
Thermal conductivity peak value	(mW/mK)	20.3	20.8	20.7	19.8	19.5	20.1	19.9
Lowest value of thermal conductivity	(mW/mK)	19.4	20.1	19.9	18.5	18.3	18.9	18.4
Moisture impregnation rate	(wt%)	1.2	1.4	0.9	1.1	1.4	0.8	1.5

division		Comparative example
		One	2	3	4	5	6	7	8	9
Silica precursor composition	(Kinds)	TEOS	MTES	TEOS	TEOS	MTES	TEOS	MTES:TEOS	MTES:TEOS	MTES:TEOS
	(Molar ratio)	100	100	100	100	100	100	95:5	90:10	98:2
Gelation step		rotation	rotation	rotation	rotation	rotation	rotation	Roll to roll	Roll to roll	Roll to roll
Surface modification step		O	X	X	O	X	X	X	X	X
Drying step		Normal pressure	Normal pressure	Normal pressure	Supercritical	Supercritical	Supercritical	Normal pressure	Normal pressure	Normal pressure
Thermal conductivity peak value	(mW/mK)	30.3	23.8	36.0	19.6	21.1	23.0	25.6	28.2	26.1
Lowest value of thermal conductivity	(mW/mK)	28.5	22.5	34.8	18.0	20.0	22.3	19.5	20.0	20.2
Moisture impregnation rate	(wt%)	3.7	1.1	X	2.3	0.9	X	1.5	2.0	1.5

As shown in Table 1, a silica precursor composition containing MTES, a silicate containing a hydrophobic group, and TEOS, a tetraalkyl silicate, in a specific molar ratio in the catalyzed sol, while rotating the bobbin on which the blanket substrate is wound It was confirmed that the gelation of Examples 1 to 7 was excellent in both the thermal conductivity and the moisture impregnation rate regardless of the drying conditions.

In addition, Examples 1 to 7 showed a very small deviation of the maximum and minimum values of thermal conductivity from the innermost to the outermost of the airgel blanket roll, 1.5 mW/mK or less, so that the aerogel in the blanket substrate was uniformly formed. there was.

Particularly, Examples 1 to 3 show the same level of thermal conductivity and moisture impregnation rate compared to Examples 4 to 7 by supercritical drying while drying at atmospheric pressure when manufacturing an airgel blanket by drying the wet gel blanket. I could confirm.

However, as shown in Table 2, in the case of Comparative Examples 1, 3, 4 and 6 using only TEOS as a silica precursor in the catalyzed sol, Comparative Example 4 additionally performing the surface modification step was performed through supercritical drying. Although the thermal conductivity was similar to that of the Example, it was confirmed that the moisture impregnation rate was increased. In addition, it was confirmed that the thermal conductivity was poor and the moisture impregnation rate was increased in Comparative Example 1, which was dried under normal pressure by only different from Comparative Example 4 and drying conditions. This is due to the fact that even if the surface modification step is additionally performed, a sufficient amount of surface modifier is not introduced to the interior of the airgel, and moisture adsorption by hydrogen bonding between the hydroxy group present on the surface of the airgel and the moisture in the solvent occurs. I think it is. In addition, in the case of Comparative Examples 3 and 6, in which the surface modification step was not additionally performed, the thermal conductivity was poor regardless of the drying conditions, and the silica airgel blanket itself exhibited hydrophilicity, so that the moisture impregnation rate could not be measured. Impregnated with. In particular, in the case of Comparative Example 3 without additionally performing the surface modification step and drying at normal pressure, the thermal conductivity was extremely poor.

In addition, in the case of Comparative Examples 2 and 5 using only MTES, which is a silicate containing a hydrophobic group as a silica precursor in the catalyzed sol, the thermal conductivity is lowered compared to Examples 1 to 3 and Examples 4 to 7 each performed the same drying step. I was able to confirm it.

In addition, even if a silica precursor composition containing MTES, a silicate containing a hydrophobic group, and TEOS, a tetraalkyl silicate, in a specific molar ratio in the catalyzed sol, the substrate for a blanket does not proceed with gelation while rotating the wound bobbin, In the case of Comparative Examples 7 to 9 in which the gelling step was performed by the roll-to-roll method, the thermal conductivity was poor compared to Examples 1 to 3 in which the same drying step was performed, the moisture impregnation rate was lowered, and the difference between the highest and lowest values of the thermal conductivity Was very large, 5.9 mW/mK or more, and it was confirmed that the airgel in the blanket substrate was formed unevenly. It is believed that this is due to the evaporation of the solvent upon gelation. In addition, in the case of Comparative Examples 7 to 9, the gelation time was lengthened due to MTES, which is a silicate containing a hydrophobic group, and accordingly, there was a problem that the apparatus for carrying out the roll-to-roll method was enlarged. Specifically, as in Comparative Examples 7 to 9, in the case of a roll-to-roll method, a conveyor belt for casting a catalytic sol or the like on a substrate and allowing gelation to occur completely must be included in the equipment, and the conveyor belt is gelled. There is a problem that the scale of the equipment becomes enormous in the mass production stage because it must be continued until it is completely achieved. In addition, as the length of the airgel blanket to be produced increases, the length of the conveyor belt becomes longer and the overall manufacturing time becomes longer due to the longer gelation time.In particular, the thinner the airgel blanket is, the longer the length is. Since this becomes longer, there is a problem that the manufacturing time is affected by the thickness and length of the blanket.

From the above experimental results, in the case of using a silica precursor composition containing a silicate containing a hydrophobic group and a tetraalkyl silicate in a specific molar ratio as a silica precursor when preparing an airgel blanket, a large amount of an organic solvent and an expensive surface modifier were used. , As the process is complicated and requires a long process time, it was possible to omit the surface modification step that hinders economical efficiency and productivity, and it was confirmed that even normal pressure drying showed the same level of physical properties as supercritical drying.

In addition, in the case of gelation while rotating the blanket substrate impregnated with the sol that is catalyzed in the gelling process of the airgel blanket, the airgel in the blanket is uniformly formed to have excellent thermal conductivity, and the physical properties for each position within the airgel blanket It was confirmed that the quality could be improved because this did not change significantly.

The above description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains will be able to understand that other specific forms can be easily modified without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects.

Claims (12)

1) adding the catalyzed sol and the blanket substrate to the reaction vessel, and impregnating the catalyst with the blanket substrate with the catalyst; And

2) rotating the substrate for a blanket impregnated with the catalyzed sol to gel,

The catalyzed sol comprises a silica precursor composition,

The silica precursor composition comprises a silicate containing a hydrophobic group and a tetraalkyl silicate,

The molar ratio of the silicate containing the hydrophobic group and the tetraalkyl silicate is 60:40 to 98:2.

The method of claim 1,

The molar ratio of the silicate containing the hydrophobic group and the tetraalkyl silicate is 85:15 to 98:2.

The method of claim 1,

The silicate containing the hydrophobic group is methyltriethoxysilane (MTES), trimethylethoxysilane (TMES), trimethylsilanol (TMS), methyltrimethoxysilane (MTMS), dimethyldiethoxysilane (DMDEOS), ethyl Triethoxysilane (ETES) and phenyl triethoxysilane (PTES) at least one selected from the group consisting of an airgel blanket manufacturing method.

The method of claim 1,

The blanket substrate is put into a reaction vessel in a state wound on a bobbin,

The method of manufacturing an airgel blanket by rotating the bobbin to rotate the substrate for blanket impregnated with the catalyzed sol.

The method of claim 1,

Injecting the catalyzed sol and the blanket substrate of step 1),

A method of injecting the catalyzed sol after putting the substrate for a blanket into the reaction vessel, a method of introducing the catalyzed sol into the reaction vessel and then introducing the blanket substrate, and Airgel blanket manufacturing method that is performed by any one of the methods of introducing the substrate.

The method of claim 1,

In step 1), the impregnation is performed while the substrate for the blanket is rotated.

The method of claim 1,

To perform step 2) before completion of step 1),

In the case of performing step 2) before completion of step 1), all of the catalyzed sol is added to the reaction vessel until gelation is completed.

The method of claim 1,

The method of manufacturing an airgel blanket is rotated at a speed of 1 rpm to 300 rpm in the blanket substrate impregnated with the catalyzed sol.

The method of claim 1,

The method for producing an airgel blanket that the catalyzed sol is a catalyzed silica sol.

The method of claim 1,

The catalyzed sol comprises a silica sol and a base catalyst,

The silica sol is a method of manufacturing an airgel blanket comprising a silica precursor composition, water and an organic solvent.

The method of claim 10,

The method of manufacturing an airgel blanket wherein the silica sol further comprises an acid catalyst.

The method of claim 1,

Further comprising the step of drying after step 2),

The drying is performed by supercritical drying, or an atmospheric drying process at 1±0.3 atm pressure and a temperature of 70°C to 200°C.

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