KR20220053213A - Method of preparing aerogel blanket - Google Patents

Abstract

The present invention relates to a method for preparing an aerogel blanket and an aerogel blanket prepared therefrom, in which gelation is performed while rotating a blanket substrate impregnated with catalyzed sol, thereby simplifying an manufacturing equipment, controlling a manufacturing time regardless of the thickness of the aerogel blanket, and improving manufacturing efficiency, and in which aerogel is uniformly formed and impregnation and drying efficiency are improved so that there is substantially no variation in physical properties such as thermal conductivity, water repellency and thickness by applying the winding to a bobbin in a state where a guide mesh and a substrate blanket are laminated as a substrate for a blanket.

Description

Airgel blanket manufacturing method {METHOD OF PREPARING AEROGEL BLANKET}

The present invention relates to a method for manufacturing a highly insulating airgel blanket.

Airgel 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 ranging from 1 to 100 nm, and has excellent properties such as ultra-lightweight/ultra-insulation/ultra-low dielectric properties. Since it is a material having a .

The biggest advantage of airgel is that it is super-insulation with a thermal conductivity of 0.300 W/m·K or less, which is lower than that of conventional organic insulation materials such as Styrofoam. that it can be solved.

In general, airgel is prepared by preparing a hydrogel from a precursor material, and removing the liquid component inside the hydrogel without destroying the microstructure. The representative airgel form can be divided into three types: powder, granule, and monolith, and is generally prepared in the form of a powder.

In the case of the powder, it is possible to produce a product in the form of an airgel blanket or an airgel sheet by complexing it with fibers, and in the case of a blanket or sheet, it has flexibility and can be bent, folded, or cut into any size or shape. can Accordingly, it is applicable not only to industrial applications such as insulation panels for LNG carriers, industrial insulation materials and space suits, transportation and vehicles, and insulation materials for power generation, but also household goods such as jackets and sports shoes. In addition, when airgel is used in fire doors as well as roofs or floors in houses such as apartments, there is a great effect in preventing fire.

Specifically, the airgel blanket in the present specification is a concept referring to a material impregnated with airgel in a base material for blankets such as fibers, and the method for manufacturing the airgel blanket is a gel casting method and after manufacturing airgel powder or granules. It is divided into a method of depositing on a base material for blanket using a binder.

Products manufactured by the gel casting method account for most of the amount used so far because of their good physical properties, and as a currently commercialized technology, a gel casting method using a roll-to-roll method is known. However, in order to manufacture the airgel blanket by the roll-to-roll technique, a conveyor belt that casts a catalyzed sol on a substrate and enables complete gelation must be included in the equipment, and the conveyor belt must be continued until gelation is complete. Therefore, there is a problem in that the scale of the equipment becomes huge in the mass production stage. In addition, as the length of the airgel blanket to be produced becomes longer, the length of the conveyor belt becomes longer and the gelation time takes longer, which increases the overall manufacturing time. In particular, the thinner the airgel blanket, the longer the length increases. As this length increases, there is a problem that the manufacturing time is affected by the thickness and length of the blanket.

Therefore, in the manufacturing method of the airgel blanket, the manufacturing equipment can be simplified and the manufacturing process efficiency can be increased, and the manufacturing time is not significantly affected by the thickness and length of the airgel blanket, which can be commercialized in the mass production process There is a need for research on a method for manufacturing an airgel blanket.

KR10-2012-0070948A

The present invention has been devised to solve the above conventional problems, and in manufacturing an airgel blanket by a gel casting method, while performing gelation while rotating the substrate for the blanket impregnated with the sol catalyzed in the gelation process, the substrate for the blanket By inserting a guide mesh into the furnace base blanket and utilizing what is wound on the bobbin, the manufacturing time can be greatly reduced, and the thickness and length of the airgel blanket do not affect the manufacturing time, and the uniformity of impregnation and drying Provided is a method for manufacturing an airgel blanket that has substantially no deviation in internal and external physical properties of the airgel blanket, and can simplify manufacturing equipment.

Another problem to be solved by the present invention is to further improve the uniformity of the airgel formed in the blanket substrate by rotating the substrate for the blanket impregnated with the catalyzed sol, so that the airgel can be uniformly formed in the substrate for the blanket. and, thus, the airgel blanket can exhibit uniform thermal conductivity as a whole, and provides an airgel blanket manufacturing method in which the thermal conductivity of the airgel blanket can be improved.

Another problem to be solved by the present invention is to provide a high-insulation airgel blanket manufactured by the airgel blanket manufacturing method.

In order to solve the above problems, the present invention comprises the steps of: 1) putting a catalyzed sol and a blanket substrate into a reaction vessel, and impregnating the blanket substrate with the catalyzed sol; and 2) rotating a substrate for a blanket impregnated with the catalyzed sol to gel, wherein the substrate for the blanket includes a guide mesh and a substrate blanket, and the guide mesh and the substrate blanket are laminated and wound on a bobbin It provides a method for manufacturing an airgel blanket that has been

In the method of manufacturing the airgel blanket, the base material for the blanket may be one wound such that a guide mesh is in contact with the bobbin, and the guide mesh has a mesh size of 1 to 30 mm and a thickness of 0.5 to 10.0 mm.

The manufacturing method of the present invention utilizes a guide mesh and a substrate blanket wound on a bobbin in a laminated state as a substrate for a blanket, and performs gelation by rotating a substrate for a blanket impregnated with a sol catalyzed in the gelation process. The physical properties of the entire blanket are uniform, the manufacturing time can be greatly reduced, and the thickness and length of the airgel blanket do not affect the manufacturing time, and the manufacturing equipment can be simplified. In particular, the present invention is advantageous in that the above-described effect is further maximized when the thickness of the substrate for blanket is thin and the length is long (thin grade), and in this case, in particular, productivity can be greatly increased.

In addition, according to an embodiment of the present invention, as a diffusion path is secured due to the presence of the guide mesh and rotation by the bobbin in the impregnation and drying process, the impregnation and drying efficiency can be greatly improved.

In addition, in the airgel blanket according to an embodiment of the present invention, the airgel is uniformly formed, so that the airgel blanket can appear uniformly without deviation in physical properties as a whole, and the fiber thickness and thermal conductivity of the airgel blanket are substantially improved because there is substantially no deviation. and can be easily used in industrial fields requiring high insulation.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with the above-described content of the invention, so the present invention is limited to the matters described in those drawings It should not be construed as being limited.
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 help the understanding of the present invention. At this time, the terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor appropriately defines the concept of the term in order to describe his invention in the best way. Based on the principle that it can be done, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

1. Manufacturing method of airgel blanket

A method of manufacturing an airgel blanket according to an embodiment of the present invention includes: 1) putting a catalyzed sol and a substrate for blanket into a reaction vessel, and impregnating the substrate for blanket with the catalyzed sol; and 2) rotating a substrate for a blanket impregnated with the catalyzed sol to gel, wherein the substrate for the blanket includes a guide mesh and a substrate blanket, and a bobbin in a state in which the guide mesh and the substrate blanket are stacked It is characterized in that it is wound on.

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

Step 1

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 in a substrate for a blanket, and preparing the catalyzed sol and prepared catalyzed sol and impregnating the catalyzed sol into the blanket substrate through inputting the blanket substrate into the reaction vessel.

The term "impregnation" used in the present invention can be made by injecting a catalyzed sol having fluidity into the substrate for a blanket, and may indicate that the catalyzed sol penetrates into pores inside the substrate for a blanket.

In addition, in step 1) according to an embodiment of the present invention, if the blanket substrate and the catalyzed sol are added to the reaction vessel, the order of the input is not particularly limited. Specifically, in step 1), a method of introducing a substrate for blanket into the reaction vessel and then catalyzed sol, a method of introducing a catalyzed sol into the reaction vessel and then introducing a substrate for blanket into the reaction vessel, and catalyzing the reaction vessel It may be input by any one of the methods of inputting the base material for the blanket while inputting the old sol. Among them, a method of introducing a catalyzed sol after inputting a base material for a blanket in terms of more uniform impregnation may be more preferable. Specifically, when the base material for the blanket is input first, since the base material for the blanket can be rotated when the catalyzed sol is added, more uniform impregnation can be induced.

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

According to an embodiment of the present invention, the substrate for the blanket includes a guide mesh and a substrate blanket, and the guide mesh and the substrate blanket are wound on a bobbin in a stacked state and put into a reaction vessel.

In the case of the conventional roll-to-roll method, physical property deviation between the initial reaction sample and the final reaction sample occurs severely during product production. In the roll-to-roll method, the substrate for blanket in a normal winding state moves along the conveyor belt as the winding is unwound, and the sol is sprayed from the top during movement, or an impregnation tank is placed so that the base material for the blanket passes through the impregnation tank so that the sol is impregnated and gelled. After the gelation is completed, the wet gel-blanket composite is rewound again, and then processes such as aging, surface modification, and drying are performed. In this process, since the loads applied to the innermost blanket and the outermost blanket in contact with the bobbin are inevitably different, there are problems such as separation of the wet gel in the innermost blanket or collapse of the structure when all processes are not completed. As a result, deviations in physical properties occur, and in particular, as apparent physical properties, there is a problem in that there is a large deviation in thickness and water repellency.

However, as in the manufacturing method according to an embodiment of the present invention, by performing the impregnation process in a state in which the substrate for the blanket is wound on the bobbin from the beginning before the sol is impregnated in the substrate for the blanket, the amount of airgel in the substrate for the blanket is maximized It is possible to reduce the amount lost while increasing the

In this process, in the case of the roll-to-roll method, since the post-process is performed by rewinding after the sol is impregnated and gelled on the blanket substrate, the insertion of the guide mesh during rewinding has a significant effect on the fluid flow in the subsequent process. may not be able to give However, in the case of the manufacturing method according to the present invention, impregnation and gelation occur in a state in which the substrate for blanket is wound on the bobbin, and in this case, gelation proceeds in the form of an aggregate, and between the surface and the surface of the substrate for the blanket in a wound state The space may disappear, and this loss of space has the potential to impede the flow of fluid in the back-end process, thereby reducing efficiency.

In order to solve this problem, as in the present invention, a guide mesh inserted as a base material for a blanket may be used. Specifically, when a guide mesh is laminated on a substrate blanket and wound on a bobbin is used as a substrate for a blanket, the substrate blanket is said to be wound on the bobbin during the process leading to impregnation, gelation, aging, surface modification, and drying. Even if the guide mesh is inserted between the substrate blankets, there may be no parts in contact with each other between the substrate blankets.

In this form, in the impregnation process, the sol can penetrate to the innermost substrate blanket close to the bobbin, and the portions that should be in contact between the substrate blankets are spaced apart due to the guide mesh and penetrate uniformly throughout the thickness direction of the substrate blanket. A possible path can be secured. In addition to this, in the drying process, a path through which air or carbon dioxide in a supercritical state can penetrate into the innermost part of the bobbin and the entire thickness direction of the substrate blanket may be sufficiently secured.

Through this, the diffusion effect can be maximized along with maximizing the contact area between the sol or drying medium and the substrate blanket, and the deviation of physical properties inside and outside the airgel blanket product, or the physical properties at both ends of the total area of the airgel blanket product Not only can the deviation be substantially eliminated, but also the effect of improving the overall physical properties can be expected.

In other words, the roll-to-roll method has a limitation in that the sol is inevitably rich in the lower part under the influence of gravity until gelation occurs during the impregnation process, and thus the deviation in physical properties, especially the water repellency, is severe. However, as in the present invention, when the sol is impregnated and gelled while being wound on the bobbin as in the present invention, the water repellency deviation can be reduced and the Through insertion, the fluid path is sufficiently secured, and thus, it is possible to implement to a level where there is substantially no deviation in physical properties, and it is possible to improve the overall physical properties.

According to an embodiment of the present invention, in the process of preparing the substrate for the blanket in a state wound on the bobbin, in order to maximize the improvement of the effect as described above, it is preferable to wind the guide mesh so that the guide mesh is located in the innermost part in contact with the bobbin. can do. That is, after laminating the substrate blanket and the guide mesh, the inner surface may be a guide mesh when the laminate is wound on the bobbin.

In addition, the guide mesh may have a mesh size of 1 mm to 40 mm. The mesh size may preferably be between 1 mm and 30 mm, or between 3 mm and 25 mm, more preferably between 5 mm and 20 mm. When the mesh size is within the range of 1 mm to 40 mm, the force to maintain the gap between the winding substrate blankets is sufficient, and the optimal effect can be realized in maximizing the contact area and securing the diffusion path.

In addition, the guide mesh may have a thickness that is less than or equal to the thickness of the substrate blanket, specifically, may be 0.5 mm to 10.0 mm, preferably 1.0 mm to 8.0 mm, and more preferably 2.5 mm to 7.0 mm. mm, most preferably from 3.0 mm to 6.0 mm. In the case of the above range, it is possible to realize the optimal effect of maximizing the contact area and securing the diffusion path in the same way as the mesh size, and furthermore, it is possible to further reduce the deviation of thermal conductivity among the physical properties, and it is possible to easily recover the solvent used in the process Therefore, a solvent recovery effect can also be expected. In addition, in consideration of the desired process yield, that is, the production amount of the airgel blanket that can be produced in one cycle, it may be preferable to select a thickness of the guide mesh that is not too thick.

The guide mesh may be a material different from that of the base blanket, and may be a non-absorbent material. In the case of a substrate blanket, a material capable of absorbing the catalyzed sol is required to facilitate the impregnation and gelation reaction. Therefore, the ability to secure a fluid path may be lost. Accordingly, it is preferable that the material is non-hygroscopic while having pores in the form of a mesh.

The guide mesh may include polyvinyl chloride, polyurethane, polyamide, polybenzimidazole, polyaramid, acrylic resin, phenolic resin, silicone resin, polyester, polyetheretherketone (PEEK), or polyolefin (e.g., polyethylene , polypropylene or a copolymer thereof, etc.), and more specifically, in the present invention, the guide mesh may be made of a material of polyolefin.

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

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

Specifically, the base blanket is polyamide, polybenzimidazole, polyaramid, acrylic resin, phenol resin, polyester, polyether ether ketone (PEEK), polyolefin (e.g., polyethylene, polypropylene, or copolymers thereof, etc.) ), cellulose, carbon, cotton, wool, hemp, nonwoven fabric, glass fiber or ceramic wool, etc., more specifically, in the present invention, the substrate blanket may be glass fiber (glass felt, glass fiber).

The base material for the blanket may be put in an appropriate form that is easy to put in according to the shape of the reaction vessel, and specifically, the base material for the blanket wound in a roll form on a bobbin to facilitate rotation in step 2) to be described later. may be introduced into the reaction vessel. At this time, the bobbin may be a shaft capable of rotating the substrate for the blanket, and any one capable of winding the substrate for the blanket may be applied without limitation. As an example, it may be to use a polygonal cylindrical column of a size that can fit inside the reaction vessel, preferably a cylindrical column. In addition, according to an embodiment of the present invention, the bobbin may include a winding rod capable of winding the blanket substrate in a roll shape, and a support plate for supporting the side portion so that the blanket substrate wound on the winding rod does not separate during rotation. . At this time, it is preferable that the winding rod has a plurality of hollows so that the catalyzed sol is also easily impregnated inside the blanket substrate. Meanwhile, the support plate may use a mesh type or include a plurality of hollows to allow the catalyzed sol to flow into the side of the blanket substrate. 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 in the reaction vessel, but in the reaction vessel of the same volume, a large amount of a blanket substrate is put in, and thus, in terms of increasing production efficiency, it is preferably fixed to the center of the reaction vessel it could be In addition, the bobbin may be positioned so that the long axis of the bobbin and the long axis of the reaction vessel are parallel to each other.

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 by a sol-gel reaction, and may specifically include an inorganic sol, an organic sol, or a combination thereof. The inorganic sol may comprise zirconia, yttrium oxide, hafnia, alumina, titania, ceria, silica, magnesium oxide, calcium oxide, magnesium fluoride, calcium fluoride, and combinations thereof, and the organic sol comprises a polyacrylate, Polyolefin, polystyrene, polyacrylonitrile, polyurethane, polyimide, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehyde, resorcinol formaldehyde, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polish anurate, polyacrylamide, various epoxies, agar, agarose, and combinations thereof. In addition, in terms of securing excellent compatibility with the blanket substrate, porosity can be further improved when formed into a gel, and manufacturing an airgel blanket having low thermal conductivity, the sol may preferably 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 the 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, water, and an organic solvent. In addition, the silica sol may be hydrolyzed at a low pH to facilitate gelation, and at this time, an acid catalyst may be used to lower the pH.

The silica precursor usable for preparing the silica sol may be a silicon-containing alkoxide-based compound, and specifically, tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), methyltri methyl triethyl orthosilicate, dimethyl diethyl orthosilicate, tetrapropyl orthosilicate, tetraisopropyl orthosilicate, tetrabutyl orthosilicate orthosilicate), tetra secondary butyl orthosilicate, tetra tertiary butyl orthosilicate, tetrahexyl orthosilicate, tetracyclohexyl orthosilicate ), tetradodecyl orthosilicate, and the like. More specifically, the silica precursor according to an embodiment of the present invention may be tetraethyl orthosilicate (TEOS).

The silica precursor may be used in an amount such that the content of silica (SiO ₂ ) included in the silica sol is 3 wt% to 30 wt%. If the content of silica is less than 3% by weight, the content of silica airgel in the finally manufactured blanket is too low, and a problem that the desired level of thermal insulation effect cannot be expected may occur, and if it exceeds 30% by weight, excessive silica airgel There is a risk that the mechanical properties, particularly flexibility, of the blanket may be deteriorated due to the formation.

In addition, the organic solvent that can be used for preparing the sol of the present invention can be used without limitation as long as it has excellent compatibility with the sol precursor and water, and specifically, it may be a polar organic solvent, and more specifically, alcohol may be using Here, the alcohol is specifically a monohydric alcohol such as methanol, ethanol, isopropanol, butanol; Or 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 thereof may be used. Among them, it may be a monohydric alcohol having 1 to 6 carbon atoms, such as methanol, ethanol, isopropanol, butanol, etc. in consideration of compatibility with water and airgel to be manufactured in the future.

The organic solvent as described above may be used in an appropriate amount in consideration of the content of the final manufactured airgel.

The silica sol according to an embodiment of the present invention may contain a silica precursor and water in a molar ratio of 1:4 to 1:1. In addition, the silica precursor and the organic solvent may be included in a weight ratio of 1:2 to 1:9, preferably 1:4 to 1:6 by weight. When the silica precursor meets the molar ratio or weight ratio with water and the organic solvent, the airgel production yield can be further increased, so 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 it is an acid catalyst that allows the pH to be 3 or less, and for example, hydrochloric acid, nitric acid or sulfuric acid may be used. In this case, the acid catalyst may be added in an amount such that the pH of the sol is 3 or less, or may be added in the form of an aqueous solution dissolved in an aqueous solvent.

In addition, examples of the base catalyst that can be used in the catalyzed sol according to an embodiment of the present invention include 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 Ethylammonium 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-(ethyl amino)ethanol, 2-(methyl Amino) ethanol, N-methyl diethanolamine, dimethylaminoethanol, diethylaminoethanol, nitrilotriethanol, 2-(2-aminoethoxy)ethanol, 1-amino-2-propanol, triethanolamine, monopropanolamine, It may be at least one selected from the group consisting of dibutanolamine and pyridine, and 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, there is a fear that the gelation in step 2) to be described later is not easy, or the gelation rate is too slow to reduce fairness. In addition, since there is a possibility that the base is precipitated when added as a solid phase, it may be preferable to be added as a solution diluted by an aqueous solvent or the above-mentioned organic solvent. At this time, the dilution ratio of the base catalyst and the organic solvent, specifically alcohol, may be 1:4 to 1:100 by volume.

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

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

When the catalyzed sol is added in step 1), the blanket substrate may be lightly pressed to ensure sufficient impregnation in order to improve bonding between the blanket substrate and the catalyzed sol. Thereafter, the drying time may be reduced by pressing the base material for the blanket to a predetermined thickness with a constant pressure to remove excess sol. In another embodiment, when the catalyzed sol is introduced into the reaction vessel, the remaining sol may be recovered when the substrate for the blanket is sufficiently impregnated to no longer change the liquid level in the reaction vessel, and at this time, the remaining sol 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 be input in an amount corresponding to 1% to 100% of the volume of the reaction vessel, specifically, the internal volume of the reaction vessel, shortening the gelation time in step 3) and reducing the amount of the substrate for the blanket In terms of uniformly forming the airgel therein, the amount is preferably 1% to 60% of the volume of the reaction vessel, more preferably 10% to 60%, even more preferably 30% to 60%. Each may be input.

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 substrate for the blanket. In addition, preferably, the input amount of the blanket base material and the catalyzed sol may satisfy the above-mentioned mutual input ratio under the conditions satisfying the input amount compared to the above-mentioned reaction vessel. When the catalyzed sol satisfies the input ratio (input amount) to the volume of the blanket substrate, the airgel blanket prepared by impregnating the catalyzed sol more evenly in 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 that the catalyzed sol is gelled alone can be prevented.

Step 2)

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

Any method and apparatus can be used as long as the rotation of the substrate for the blanket impregnated with the catalyzed sol is rotated during gelation in the reaction vessel. Specifically, in step 1), the substrate for the blanket is wound on a bobbin. When the catalyzed sol-impregnated blanket substrate is present in the reaction vessel in a state wound around the bobbin, when the catalyzed sol is impregnated and fixed, rotating the bobbin rotates the catalyzed sol-impregnated blanket substrate. can

In the present invention, the gelation may be to form a network structure from a catalyzed sol, and the network structure is a series of specific polygons having one or more types of atomic arrangement. It may indicate a structure in a planar network shape or a structure in which a three-dimensional skeletal structure is formed by sharing vertices, corners, faces, etc. of a specific polyhedron.

According to an embodiment of the present invention, the gelation reaction may be performed after sealing the reaction vessel into which the catalyzed sol and the substrate for the blanket are put. In addition, according to an embodiment of the present invention, the long axis may be rotated by arranging it in a horizontal direction, that is, in a horizontal direction. If the reaction vessel (body) is a cylindrical reaction vessel, it may be rotated by laying down the cylindrical reaction vessel. 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 substrate for the blanket impregnated with the catalyzed sol present in the reaction vessel, the type is not limited. Any device known in the art can be used as long as it can be rotated. Specifically, any known device may be used as long as it is capable of fixing the position of the bobbin in the reaction vessel and rotating the bobbin having the fixed position. 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 step 1) is completed, step 2) may be started, and step 1) and step 2) may be sequentially performed.

According to another embodiment of the present invention, it may be to start and perform step 2) before step 1) is completed. Until the gelation is completed, specifically, the catalyzed sol may be fully introduced 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 as far as rotational speed that allows the airgel in the blanket to be uniformly formed, for example 1 rpm to 300 rpm, preferably 5 The gelation may be performed while rotating at a rotation speed of rpm to 150 rpm, 5 rpm to 100 rpm, and more preferably 10 rpm to 30 rpm. When the reaction vessel satisfies the rotation speed in the above range, the sol in the blanket substrate can be evenly impregnated, so the airgel is more uniformly formed during gelation. There is an advantage of increasing the safety of the airgel blanket manufacturing process by increasing the stability of the container and the device for rotating it.

In the present invention, as the airgel blanket is manufactured by putting all of the catalyzed sol and the blanket substrate in the reaction vessel and gelling it, unlike the conventional roll-to-roll method, a separate moving element such as a conveyor belt is not required. has the advantage of significant savings. 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 form a gel while continuously moving the moving element, the entire substrate for blanket is simultaneously gelled. The gelation process according to an embodiment of the present invention, even if a blanket substrate having the same thickness and length is used because gelation cannot but be made sequentially according to the passage of time while continuously supplying the blanket substrate and the catalyzed sol. A problem arises that takes significantly longer time. In particular, as the blanket substrate lengthens, the problem that the gelation process time becomes longer in order to achieve sufficient gelation as a whole of the blanket substrate becomes more prominent. Since the length and thickness of the blanket base material do not affect the gelation time, even if a long blanket base material is used, the manufacturing time can be significantly reduced to maximize the 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 airgel is more uniformly dispersed than the roll-to-roll method in which the reaction vessel is not rotated or gelled on a moving element. It is possible to manufacture an airgel blanket, so that the thickness of the airgel blanket to be manufactured is the same as or extremely similar to the thickness of the base material for the blanket, and there is an excellent heat insulation effect.

In addition, according to an embodiment of the present invention, the rotation of step 2) may be performed with the rotation axis of the base material for the blanket in the transverse direction. Here, the lateral direction may mean a direction horizontal to the ground. When the rotation is carried out with the rotation axis of the blanket base material in the longitudinal direction (direction perpendicular to the paper surface) or diagonal direction (direction having a constant angle between the direction horizontal and vertical to the paper surface), catalyzed by gravity Apart from the fact that the sol or the catalyzed sol impregnated in the blanket substrate may be driven in the direction of the ground, uniform impregnation and gelation are induced in the direction perpendicular to the rotation axis of the blanket substrate by centrifugal force. In a direction horizontal to the rotation axis of the substrate for blanket, a problem in which non-uniform impregnation and gelation is induced may occur. Therefore, in order to induce uniform impregnation and gelation by uniformly contacting the catalyzed sol on all sides of the substrate for blanket, that is, both in the direction perpendicular to the axis of rotation of the substrate for blanket as well as in the horizontal direction, step 2) The rotation of the blanket may be preferably carried out with the axis of rotation of the base material for the blanket in the transverse direction.

ripening stage

Additionally, in the manufacturing method according to an embodiment of the present invention, the aging step may be performed as a process for allowing the wet gel blanket complex to be left at an appropriate temperature to completely effect a chemical change, and the aging step further enhances the formed network structure. It can be formed firmly, and it is possible to enhance the mechanical stability of the airgel blanket of the present invention.

The aging step of the present invention is a solution obtained by diluting a basic catalyst such as sodium hydroxide (NaOH), potassium hydroxide (KOH), ammonium hydroxide (NH ₄ OH), triethylamine, and pyridine in an organic solvent to a concentration of 1% to 10%. By adding, Si-O-Si bonding is maximally induced in the airgel to make the network structure of silica gel more robust, thereby making it easier to maintain the pore structure in the rapid drying process to be performed later. In this case, the organic solvent may be the above-mentioned alcohol (polar organic solvent), and specifically may include ethanol.

In addition, the aging step should be performed in an appropriate temperature range for optimal pore structure reinforcement, and the aging step of the present invention may be performed by allowing it to stand at a temperature of 30° C. to 70° C. for 1 hour to 10 hours. If the aging temperature is less than 30 ℃, there may be a problem that the aging time is excessively long, leading to an increase in the overall process time, leading to a decrease in productivity, and when the aging temperature is more than 70 ° C. There may be a problem of increasing the loss of raw materials and increasing the cost of raw materials.

Surface modification step (hydrophobization step)

In addition, according to an embodiment of the present invention, as for manufacturing a hydrophobic airgel blanket, a surface modification step may be further performed.

When a hydrophilic functional group present on the surface of the airgel is substituted with a hydrophobic functional group, it is possible to minimize the shrinkage of pores due to the surface tension of the solvent during drying of the airgel by the repulsive force between the hydrophobic functional groups. The dried airgel maintains low thermal conductivity immediately after drying, but a hydroxyl functional group present on the surface of the airgel, such as a hydrophilic silanol group (Si-OH) present on the silica surface when the airgel is a silica airgel, absorbs water in the air. There is a disadvantage in that the thermal conductivity gradually increases by absorption. Therefore, in order to maintain low thermal conductivity, it is necessary to modify the airgel surface to be hydrophobic.

Accordingly, the surface modification according to an embodiment of the present invention may be performed by a surface modifier including a polar solvent and an organosilane compound.

The polar solvent may be methanol, ethanol or isopropyl alcohol, and the like, and the organosilane compound is trimethylchlorosilane (TMCS), hexamethyldisilazane (HMDS), methyltrimethoxysilane. , trimethylethoxysilane, ethyltriethoxysilane, or phenyltriethoxysilane may be used, and specifically, hexamethyldisilazane may be used.

The surface modification is preferably mixed in a volume ratio of 1 to 10 with respect to the gel in the case of a solvent, and 0.1 to 10 by volume in the case of an organosilane compound with respect to the gel. When the volume ratio of the organosilane compound is less than 0.1, the reaction time becomes excessively long and the surface modification efficiency may decrease. can cause

In addition, according to an embodiment of the present invention, the aging step and the surface modification step may be performed in a separate reaction vessel after recovering the gelled silica wet gel blanket, or performed inside the gelling reaction vessel. In view of the efficiency of the process and the simplification of equipment, the aging and surface modification steps may be performed in the reaction vessel in which the gelation is preferably performed. In addition, when performing the aging and surface modification steps in the reaction vessel in which gelation is performed, the wet gel-blanket complex prepared in step 3) may be rotating, and aging and surface modification are performed while rotating. Since the solvent and the surface modifier can penetrate better, and the dispersion within the wet gel blanket composite after penetration can be made better, there is an advantage in that the aging efficiency and the surface modification efficiency are greatly improved.

After performing the surface modification step, a hydrophobic wet gel blanket composite can be obtained.

drying and washing steps

In addition, the wet gel blanket composite according to an embodiment of the present invention may be dried to manufacture an airgel blanket.

On the other hand, the manufacturing method according to an embodiment of the present invention may further perform the washing step before drying. The washing removes impurities (sodium ions, unreacted products, by-products, etc.) generated during the reaction and residual ammonia that may react with CO ₂ during supercritical drying to generate an ammonium carbonate salt, thereby obtaining a high-purity hydrophobic silica airgel For this purpose, it can be carried out by a dilution process or an exchange process using a non-polar organic solvent.

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 as it is, and the drying step may be performed by supercritical drying or atmospheric drying process. .

The supercritical drying process may be performed using supercritical carbon dioxide. Carbon dioxide (CO2) is in a gaseous state at room temperature and pressure, but when it exceeds the limit of a certain temperature and high pressure called a supercritical point, the evaporation process does not occur and it becomes a critical state, in which gas and liquid cannot be distinguished. The carbon dioxide in it is called supercritical carbon dioxide.

Supercritical carbon dioxide has a molecular density close to that of a liquid, but has a gas-like property due to low viscosity, fast diffusion, high thermal conductivity, high drying efficiency, and shortening of the drying process time.

Specifically, in the supercritical drying process, a wet gel blanket aged in a supercritical drying reactor is put, and then liquid CO ₂ is filled and a solvent replacement process of replacing the alcohol solvent in the wet gel with CO ₂ is performed. After that, after raising the temperature to 40°C to 70°C at a constant temperature increase rate, specifically 0.1°C/min to 1°C/min, a pressure equal to or greater than the pressure at which carbon dioxide becomes a supercritical state, specifically 100 bar to 150 bar By maintaining a pressure of bar, it is maintained in a supercritical state of carbon dioxide for a certain time, specifically, for 20 minutes to 1 hour. In general, carbon dioxide becomes a supercritical state at a temperature of 31° C. and a pressure of 73.8 bar. The airgel blanket can be manufactured by maintaining the carbon dioxide at a constant temperature and pressure at which the carbon dioxide becomes supercritical for 2 hours to 12 hours, more specifically, for 2 hours to 6 hours, and then gradually removing the pressure to complete the supercritical drying process. can

In addition, in the case of the atmospheric drying process, it may be performed according to a conventional method such as hot air drying or IR drying at a temperature of 70° C. 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, particularly low tap density and high porosity along with high hydrophobicity, and the silica airgel-containing blanket including the same has excellent mechanical flexibility with low thermal conductivity.

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

After all of the above series of processes are completed, the step of removing the guide mesh may be additionally performed. In the case of the above processes, since the base material for the blanket is wound on the bobbin, the guide mesh can be naturally removed from the blanket when the winding is unwound, which can be simply performed in the final productization process.

2. Airgel blanket manufacturing device

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

Here, the blanket may mean a substrate for a blanket before the catalyzed sol is added, a substrate for a blanket impregnated with the catalyzed sol, and/or a wet gel blanket after gelation, and the state of the substrate for the blanket is determined by each step. can be properly interpreted accordingly.

bobbin

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

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

On the other hand, the outside of the blanket wound on the winding rod can be rapidly impregnated with the catalyzed sol to stably gel, but there is a problem in that it takes a lot of time for the inside of the blanket to be impregnated with the catalyzed sol. In order to prevent this, the outer peripheral surface of the winding rod includes a plurality of connection holes connected to the hollow.

That is, the winding rod has a hollow formed therein 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 is impregnated inside the blanket wound on the winding rod. A plurality of connection holes are formed so that it becomes possible. Accordingly, it is possible to gel the outside and inside of the blanket by simultaneously impregnating the catalyzed sol, as a result, the time required for the gelation of the blanket can be greatly reduced, and as a result, the entire blanket can be uniformly gelled. .

On the other hand, the plurality of connection holes have a diameter of 3 to 5 mm, and are formed at regular intervals on the outer peripheral surface of the winding rod. Accordingly, it is possible to uniformly supply the catalyzed sol to the entire blanket wound on the outer circumferential surface of the winding rod, and thus the entire inside of the blanket can be uniformly gelled.

The support plate supports the blanket wound on the winding rod not to be wound irregularly, has a disk shape, is coupled to both ends of the winding rod, respectively, and supports the side of the blanket wound on 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 in 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 is formed with 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.

Accordingly, the bobbin includes a winding rod and a support plate, and thus the blanket can be wound in a roll shape.

main body

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

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

In particular, the gelation chamber of the gelation tank has a U'-shaped cross-sectional shape with a curvature corresponding to the blanket wound on the winding rod and the upper part being opened by a cover, and accordingly, when silica sol flows into the gelation chamber, silica sol The contact force of 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 wall surfaces 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 the through-holes formed in both wall surfaces of the gelation chamber, and the end of the bobbin accommodated in the gelation chamber is installed to transmit power.

For example, a straight-line coupling protrusion is formed on one surface of the rotating member, and a straight-line 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 rotatably installed inside the gelation tank.

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

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

On the other hand, the aging member, the surface modifying member and the drying member are further installed on the mounting table of the second installation member.

drive member

The driving member is for rotating the bobbin accommodated in the gelation tank, and is connected to the other rotating member provided in the gelation tank to transmit power. That is, when the driving member rotates the rotating member, it can rotate the bobbin accommodated in the gelation tank in conjunction with the rotating member.

Catalyzed sol supply member

The catalyzed sol supply member is to gel the blanket by impregnating the blanket wound on the bobbin by injecting silica sol into the gelation tank. supply to the firebox.

Absence of ripening

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.

surface modification member

The surface modifying member is for modifying the surface of the blanket wound on the bobbin by injecting a surface modifying agent into the gelation tank.

drying member

The drying member is for drying the blanket wound on the bobbin by supplying high-temperature hot air to the gelation tank, and is installed on the mounting table and increases the temperature of the gelation tank to dry the blanket accommodated in the gelation 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, and can greatly increase the productivity of the airgel blanket, and as a result, the airgel blanket can be mass-produced.

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 because the bobbin rotates, the entire blanket wound on the bobbin is uniformly It can be gelled, 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'-shaped cross-section, the blanket wound on the bobbin can be more effectively gelled.

Further, 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 peripheral surface of the winding rod may include a fixing clip to which the winding point of the blanket is fitted and fixed.

That is, the fixing clip has a pin shape with 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 starting point of the winding rod of the blanket can be fixed 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.

3. Airgel blanket

The present invention provides an airgel blanket with significantly improved insulation as a whole through the formation of uniform water repellency and thermal conductivity in the blanket and uniform thickness of the blanket.

At this time, the airgel blanket is characterized in that the thermal conductivity deviation within the blanket is 3.0 mW/mK or less, and preferably 2.0 mW/mK or less or 1.0 mW/mK or less. At this time, having a value of 0 because there is no difference, that is, having the same thermal conductivity in the blanket may be included in the scope of the present invention.

In addition, the airgel blanket may have a thickness deviation of 1.5 mm or less, 1.2 mm or less, 0.7 mm or less, preferably 0.5 mm or less.

The thermal conductivity and thickness deviation are characteristics that can appear in all arbitrarily cut airgel blankets, specifically in an area of 0.01 m ² to 10.0 m ² , more specifically in an area of 0.36 m ² to 5.0 m ² , both ends It may be the difference between values measured in an area each 30 cm apart from.

As an example, the thermal conductivity and thickness of the airgel blanket are obtained by obtaining a plurality of samples having a constant size in the airgel blanket at regular intervals, and for each sample, NETZSCH's HFM 436 Lambda equipment is used at room temperature (23±5° C.) ) was measured for thermal conductivity. In a plurality of samples, it may be shown by comparing the thermal conductivity values measured in an area each 30 cm apart from both ends.

At this time, the number of samples in the airgel blanket may vary depending on the length of the airgel blanket, and the number is not limited, and may be 2 to 20, 3 to 10, 3 to 5, for example.

Specifically, in the case of an airgel blanket roll with a length of 3.5 m, 5 samples having a size of 30 cm X 30 cm were obtained at a regular interval of 50 cm from the innermost side to the outermost side of the airgel blanket roll, and the thermal conductivity for each sample was determined. can be measured In this case, the thermal conductivity may be measured by a method to be described later.

In addition, according to an embodiment of the present invention, the airgel blanket includes airgel and a base material for a blanket, and specifically, airgel may be formed inside and on the surface of the base material for the blanket, for example, on the inside and surface of the base material for the blanket A large amount of airgel particles may be uniformly formed, and the airgel blanket may have an improved thermal conductivity of 10 mW/mK to 20 mW/mK.

The above thermal conductivity is a value measured at room temperature (23±5° C.) according to a heat flow method using NETZSCH's HFM 436 Lambda equipment.

Accordingly, the airgel blanket of the present invention can be usefully used as a heat insulating material, a heat insulating material, or a non-combustible material for plant facilities for thermal insulation and cold storage such as piping of various industrial facilities or industrial furnaces, as well as aircraft, ships, automobiles, and building structures.

Example

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

Preparation Example: Preparation of Silica Sol and Catalyst Solution

Tetraethyl orthosilicate (TEOS) and water were mixed in a molar ratio of 1:4, and ethanol having a weight ratio of TEOS and 1:5 was added to prepare a silica sol. Hydrochloric acid was added so that the pH of the silica sol was 3 or less to promote hydrolysis. A silica sol was prepared by mixing 0.2 parts by weight of an opacifying agent TiO ₂ and 0.2 parts by weight of a flame retardant, Ultracarb (LKAB, Inc.) with respect to 100 parts by weight of the silica sol and stirring for 30 minutes, and separately from this, a 1% by volume ammonia ethanol solution ( base catalyst solution). A catalyzed sol is prepared by mixing the silica sol and the base catalyst solution in a volume ratio of 9:1.

Example 1

In the reaction vessel, 3T (3.0 mm) guide mesh and 10T (10.0 mm) glass fiber made of polyethylene material having a mesh size of 7.0 mm are wound on a bobbin, and wound so that the guide mesh is in contact with the bobbin. fixed. The catalyzed sol prepared in Preparation Example was put into a reaction vessel, and gelation was performed while rotating a bobbin wound with a substrate for blanket. At this time, the feed rate 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 was no longer changed, the remaining sol was recovered by opening a drain valve coupled to the reaction vessel. After 30 minutes, after the gelation was completed, the aging solution was added to the reaction vessel, and the bobbin was rotated to perform aging. At this time, the aging solution was a dilution of 5% by volume of ammonia ethanol, and was aged at a temperature of 70° C. for 100 minutes. When the aging is completed, the drain valve is opened to recover the aging solution. Thereafter, the surface modification solution was introduced into the reaction vessel to perform surface modification while rotating the bobbin, and the surface modification solution was recovered after completion. At this time, the surface modification solution is a 10 vol% hexamethyldisilazane (HMDS) dilution in ethanol, and an amount having the same volume ratio as that of the wet gel-blanket complex is added. Surface modification (hydrophobization) is performed at room temperature for 8 hours. After completion of the surface modification reaction, the wet gel blanket was placed in a supercritical extractor, CO ₂ was injected, and the temperature in the extractor was raised to 60 °C over 1 hour, and supercritical drying was performed at 60 °C and 100 bar. The hydrophobic silica airgel blanket on which supercritical drying was completed was dried under atmospheric pressure in an oven at 200° C. for 2 hours to completely remove the remaining salt and moisture to prepare a hydrophobic silica airgel blanket.

Example 2

The same method as in Example 1, except that in Example 1, a 5T (5.0 mm) guide mesh made of polyethylene having a mesh size of 16.0 mm was used instead of a 3T (3.0 mm) guide mesh made of polyethylene having a mesh size of 7.0 mm. to prepare a hydrophobic silica airgel blanket.

Example 3

The same method as in Example 1, except that in Example 1, a 7T (7.0 mm) guide mesh made of polyethylene having a mesh size of 12.0 mm was used instead of a 3T (3.0 mm) guide mesh made of polyethylene having a mesh size of 7.0 mm. to prepare a hydrophobic silica airgel blanket.

Example 4

The same method as in Example 1, except that in Example 1, a 5T (5.0 mm) guide mesh made of polyethylene having a mesh size of 40.0 mm was used instead of a 3T (3.0 mm) guide mesh made of polyethylene having a mesh size of 7.0 mm. to prepare a hydrophobic silica airgel blanket.

Comparative Example 1

A hydrophobic silica airgel blanket was prepared in the same manner as in Example 1, except that only glass fibers (substrate blanket) without a guide mesh were wound on the bobbin when preparing the substrate for the blanket in Example 1.

Comparative Example 2

A hydrophobic silica airgel blanket was prepared in the same manner as in Example 1, except that the catalyzed sol was sufficiently introduced into the reaction vessel so that the substrate for the blanket was completely immersed in the catalyzed sol without rotating the bobbin in Example 1 did

Comparative Example 3

A hydrophobic silica airgel blanket was prepared in the same manner as in Comparative Example 1, except that in Comparative Example 1, the catalyzed sol was sufficiently introduced into the reaction vessel so that the substrate for the blanket was completely submerged in the catalyzed sol without rotating the bobbin. did

Comparative Example 4

The catalyzed sol prepared in Preparation Example is sprayed so that the sol is sufficiently impregnated into the substrate for blanket moving along the conveyor belt, and the wet gel-blanket complex in which the sol is impregnated into the substrate for blanket through a roller at the end of the conveyor belt was wound. The substrate for the blanket impregnated with the catalyzed sol in the wound state was put into the reaction vessel, and then aging, surface modification, and drying processes were performed in the same manner as in Example 1 to prepare a hydrophobic silica airgel blanket.

Experimental Example 1. Evaluation of the physical properties of the airgel blanket

Thermal conductivity, thickness, and moisture impregnation rate were measured for the hydrophobic silica airgel blankets prepared in Examples and Comparative Examples, but in each airgel blanket, the innermost (in) and outermost (out) in the state wound on the bobbin Each of the points was measured at a distance of 30 cm in the longitudinal direction from this as both ends.

1) Room temperature thermal conductivity (mW/mK) and thickness (mm)

In the airgel blankets prepared in Examples and Comparative Examples, 5 samples having a size of 30 cm X 30 cm were prepared for each blanket, and the samples were prepared at room temperature (23±5° C.) using NETZSCH’s HFM 436 Lambda equipment. Thermal conductivity was measured. 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 roll prepared in each Example and Comparative Example. The thermal conductivity of each of the five samples was measured.

The thermal conductivity is measured by a heat flux transducer in the equipment measuring the heat flow of a sample located between a hot plate and a cold plate, and through this, the thermal conductivity value A calibration factor (N) can be obtained from a known reference material, and the calculated value of thermal conductivity is obtained from the value of N and the measured heat flow of the sample. In this process, the thickness of the sample is also derived as a measurement value of the device.

2) Moisture impregnation rate measurement (wt%)

The moisture impregnation rate of the silica airgel blanket prepared in each Example and Comparative Example was measured.

Specifically, according to ASTM C1511, a specimen having a size of 25.4 cm x 25.4 cm was floated on distilled water at 21 ± 2 °C, and a 6.4 mm mesh screen was placed on the specimen and submerged to 127 mm below the water level. After 15 minutes, remove the screen, and when the specimen floats, pick up the specimen with a clamp and hang it vertically for 60 ± 5 seconds.

The lower the moisture impregnation rate, the higher the degree of hydrophobicity of the airgel blanket.

Fiber thickness (mm) Moisture impregnation rate (wt%) Thermal Conductivity (mW/mK) in out in out in out Example 1 9.9 10.3 2.2 1.7 17.9 18.1 Example 2 9.7 10.0 2.6 2.2 17.5 17.2 Example 3 9.9 10.1 2.3 2.0 17.7 17.9 Example 4 9.7 10.2 2.3 2.4 17.7 18.3 Comparative Example 1 8.8 10.1 4.9 4.6 22.6 20.7 Comparative Example 2 7.3 12.6 89.7 1.9 23.5 17.9 Comparative Example 3 8.0 13.1 93.3 5.1 24.4 21.3 Comparative Example 4 9.5 10.1 4.3 3.1 18.7 17.7

As shown in Table 1, in the case of Examples 1 to 4, it can be seen that both the water repellency and the thermal conductivity are superior to those of Comparative Example 1, and the deviation is also very small. In addition, the fiber thickness deviation is also about 0.5 mm in Examples 1 to 4, but in Comparative Example 1, it can be seen that the deviation is relatively severe at a level exceeding 1.0 mm.

In addition, in the case of Comparative Examples 2 and 3, the process was performed without rotation during impregnation and gelation, and it can be seen that the fiber thickness, water repellency, and thermal conductivity are very different in all physical properties, which is a blanket in the catalyzed sol. Although the substrate was completely submerged, it was confirmed that the result was very poor as described above due to the problem that the sol was concentrated in the direction of gravity and did not penetrate to the innermost part of the bobbin.

In addition, in the case of Comparative Example 4, it is by the conventional roll-to-roll method, but overall physical properties themselves are inferior to Examples 1 to 4, and in Examples 1 to 4 in water repellency, the deviation is within 20%, but in Comparative Example 4 In this case, it can be seen that the deviation is about 30%. In addition, it can be inferred that the deviation of the physical properties shown in Comparative Example 4 cannot be reduced even by inserting a guide mesh, which is a result in contrast to the examples according to the present invention.

Through this, it can be seen that when the manufacturing method according to the present invention is applied, the physical property deviation can be eliminated as well as the physical property improvement.

Experimental Example 2. Evaluation of solvent recovery rate

Solvent recovery rates were additionally confirmed for Examples 1 to 4 and Examples 5 and 6 below.

Example 5

The same as in Example 1 except that in Example 1, a 0.2T (0.2 mm) guide mesh made of polyethylene having a mesh size of 0.6 mm was used instead of a 3T (3.0 mm) guide mesh made of polyethylene having a mesh size of 7.0 mm. A hydrophobic silica airgel blanket was prepared by this method.

Example 6

The same as in Example 1 except that in Example 1, a 0.2T (0.2 mm) guide mesh made of polyethylene having a mesh size of 7.0 mm was used instead of a 3T (3.0 mm) guide mesh made of polyethylene having a mesh size of 7.0 mm. A hydrophobic silica airgel blanket was prepared by this method.

1) Solvent recovery (%)

In each Example and Comparative Example, the weight of the wet gel-blanket complex before supercritical drying and the weight of the airgel blanket after supercritical drying were measured to calculate the weight of the solvent before supercritical drying, and the wet gel-blanket complex was recovered from the solvent. was measured and expressed by the following formula.

[Equation 1]

Solvent recovery rate (%) = [(weight of solvent recovered after drying) / {(weight of wet gel-blanket complex before drying)-(weight of airgel blanket after drying)}] x 100

Here, the wet gel-blanket composite and the airgel blanket are the weights of the state in which the bobbin and the guide mesh are removed.

Solvent recovery (%) Example 1 99.1 Example 2 99.3 Example 3 98.6 Example 4 98.8 Example 5 91.5 Example 6 90.3

Referring to Table 2, the thickness of the guide mesh is smaller than or equal to the thickness of the substrate blanket in terms of solvent recovery rate, looking at Examples 5 and 6 to which the 0.2T guide mesh is applied, independently of the physical properties of the airgel blanket. It can be confirmed that it is preferable to apply at least 0.5T (0.5 mm) or more.

100: bobbin 110: winding rod
120: support plate 200: body
210: gelation tank 212: discharge unit
213: inlet 214: cover
215: rotating member 216: rotating handle
220: first installation member 230: second installation member
231: bottom 232: mounting table
233: stairs 300: driving member
400: catalyzed sol supply member

Claims (15)

1) putting the catalyzed sol and a substrate for blanket into a reaction vessel, and impregnating the substrate for blanket with the catalyzed sol; and
2) rotating the substrate for a blanket impregnated with the catalyzed sol to gel it;
The substrate for the blanket includes a guide mesh and a substrate blanket, and the guide mesh and the substrate blanket are wound on a bobbin in a stacked state.
According to claim 1,
The method for manufacturing an airgel blanket, wherein the substrate for the blanket is wound such that the guide mesh is in contact with the bobbin.
According to claim 1,
The guide mesh is a method of manufacturing an airgel blanket having a mesh size of 1 mm to 40 mm.
According to claim 1,
The thickness of the guide mesh is less than or equal to the thickness of the base blanket, the method of manufacturing an airgel blanket.
According to claim 1,
The method for producing an airgel blanket is that the base material for the blanket is rotated by rotation of the bobbin.
According to claim 1,
In step 1), the impregnation is a method of manufacturing an airgel blanket that is performed while the base material for the blanket rotates.
According to claim 1,
to perform step 2) before completion of step 1),
When step 2) is performed before completion of step 1), the method for producing an airgel blanket is to inject all of the catalyzed sol into the reaction vessel until gelation is complete.
According to claim 1,
The rotation of step 2) is a method of manufacturing an airgel blanket that is carried out with the axis of rotation of the base material for the blanket in the transverse direction.
According to claim 1,
The method for producing an airgel blanket, wherein the catalyzed sol-impregnated blanket substrate is rotated at a speed of 1 rpm to 300 rpm.
According to claim 1,
The method for producing an airgel blanket is that the catalyzed sol is added in an amount of 80% to 120% based on the volume of the base material for the blanket.
According to claim 1,
The method for producing an airgel blanket, wherein the catalyzed sol is a catalyzed silica sol.
According to claim 1,
The catalyzed sol is one comprising a precursor solution and a base catalyst,
The precursor solution is a method of manufacturing an airgel blanket comprising a precursor, water and an organic solvent.
According to claim 1,
After step 2), aging; and surface-modifying; further comprising,
The aging and surface modification are performed while rotating the wet gel-blanket complex prepared in step 2) in the reaction vessel.
According to claim 1,
Step 2) followed by drying; and removing the guide mesh; further comprising
The drying is supercritical drying, or 1±0.3 atm pressure and a method of manufacturing an airgel blanket that is performed by an atmospheric drying process at a temperature of 70 ℃ to 200 ℃.
According to claim 1,
After step 2),
Aging the wet gel-blanket complex prepared in step 2);
surface-modifying the aged wet gel-blanket complex to make it hydrophobic;
drying the hydrophobized wet gel-blanket composite by supercritical drying, or atmospheric drying at a pressure of 1±0.3 atm and a temperature of 70° C. to 200° C.; and
The method of manufacturing an airgel blanket further comprising; removing the guide mesh from the dried wet gel-blanket complex.

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