KR20110097252A - Heat insulation articles without segregation of insulating nano-powder and its manufacturing method - Google Patents

Abstract

The present invention provides a variety of molded articles expressing heat insulating properties, especially aerogels, in particular aerogels, more particularly silica aerogels, which are not separated from sheets, mats or molded articles containing them, and various molded articles expressing heat insulating functions and their preparation. It is about a method.
Aerogels are impregnated with organic solvents, mixed with polymer resin melts, and spun by electrospinning. It will not escape between the woven fabrics.
Since the aerogel ultrafine particle powder expressing adiabatic properties does not escape or scatter from the nanofibers, it is not harmful to the human body, and there is no local adiabatic characteristic deviation and deterioration phenomenon in the insulator due to uneven dispersion of the adiabatic particles.
As well as the manufacture of insulators for industrial and construction, it is possible to manufacture a thin insulation molded body using a variety of polymer resins, it is applicable to the production of various types of insulation suits applied to the human body, such as winter clothes, fire fighting suits, winter boots.

Description

Heat insulator in which the insulating nanopowder is not separated from the heat insulator and a method of manufacturing the heat insulator {HEAT INSULATION ARTICLES WITHOUT SEGREGATION OF INSULATING NANO-POWDER AND ITS MANUFACTURING METHOD}

The present invention relates to the manufacture of a heat insulating sheet, a heat insulating mat or a heat insulating molded article, and more particularly, to heat insulating sheet by allowing ultra-sized ultra-fine powders expressing heat insulating performance to be collected in a nano network structure of a nano fiber cloth layer composed of nano fibers. The present invention relates to a thermally insulating sheet, a thermally insulating mat or a thermally insulating molded product which is not separated from, separated from, or scattered from the thermally insulating material.

Insulation and insulation are another most direct way of low carbon green growth. 10% thermal and thermal insulation effect can save 10% energy by simple calculation and have 10% suppression of carbon dioxide generation. For this reason, research on developing high-performance insulation and thermal insulation materials is a very effective task to solve human energy and environmental problems.

Human studies on thermal insulation and insulation have a long history, and various types of silicate minerals with pores as natural materials have been proposed, including aerogels, which are artificially synthesized materials. Among them, aerogel is a solid material composed of a highly porous network having micro-sized and meso-sized pores. In addition to ultra-light and ultra-insulated properties, aerogels are expected to be used for various applications such as catalytic materials, optical and acoustic materials, and low dielectric materials. There are various types of aerogels, and many types of aerogels have been proposed, such as organic aerogels such as polyimide aerogels, metal carbide aerogels, carbon aerogels, silica aerogels, and inorganic aerogels such as alumina aerogels.

Silica aerogel is a material with excellent thermal insulation and heat insulating properties among various airgels. For this reason, numerous patents related to the manufacture of silica aerogels as thermal insulation and thermal insulation materials, such as Korean Patent 10-0680039, US Patent Publication 2009-0247655, US Patent Publication 2008-0311398, US Patent Publication 2007-0167534, US Patent Publication 2004- 0132846, US Patent Publication 2006-0229374, US Patent Publication 2004-0132845, US Patent Publication 2004-0087670, US Patent Publication 2004-0077738, US Patent 4,987,327, US Patent 4,717,708, and various research results have been proposed as well as already The production facilities for mass production of silica aerogels are being built and operated around the world.

However, aerogels, including silica aerogels, are extremely lightweight and ultrafine nanopowders, and thus are limited in their application and application as a fine powder state. Therefore, in order to utilize and utilize the characteristics of the airgel, it is necessary to be able to change from these fine powder states into various forms depending on the use, and to maintain or maintain the shape which is physicochemically, mechanically and stably. Accordingly, numerous patents have been proposed for shaping silica aerogels into various forms for use as thermal insulation and insulation. They are sheet-like, for example, Korean Patent Publication No. 10-2007-0052269, US Patent Publication 2009-0029147, US Patent Publication 2008-0241490, Matt, such as a plate, such as US Patent Publication 2009-0229032, US Patent Publication 2007-0014979, US Patent Publication 2009-0029109, U.S. Patent Publication 2006-0269734, U.S. Patent Publication 2006-0199455, U.S. Patent Publication 2009-0104401, U.S. Patent Publication 2002-0094426, As a bulk form, for example U.S. Patent Publication 2008-0303059, U.S. Patent Publication 2006-0246806, U.S. Patent Application Publication No. 2006-0144013, annular band shape, for example, U.S. Patent Publication 2007-0176282, U.S. Patent Publication 2007-0102055, U.S. Patent Publication 2006-0196568 or a composite that does not maintain a particular form, for example, U.S. Patent Publication 2008-0105373, US Patent Publication 2008-0087870, US Patent Publication 2007-0208124, US Patent Publication 2009-0082479, US Patent Publication 2008-0287561 and the like in a variety of forms. Some of these patents have already been put to practical use by Aspen, Inc., and are produced as products shaped as insulation mats or insulation sheets.

The method of shaping the silica aerogels proposed in these patents, including this practical product, an insulating mat or an insulating sheet, is to make the silica aerogels into a composite with the fibers, or to shape them with an adhesive or to adhere them to the fibers with an adhesive. . Or during the manufacturing process of silica aerogels using aerogels before drying using a method of forming a fibrous and composite phase and drying in a supercritical state and then shaping.

When using a silica airgel to form a molded article for the purpose of thermal insulation, the molded article must meet several conditions. First, you must have a stable image. Second, even if the silica aerogel is inherent in the desired stable molded body, the structure of the silica aerogel should not be destroyed or altered to lose or degrade the original insulation and thermal insulation function. Third, silica aerogels contained in or embedded in stable moldings should not be separated or separated during use.

However, molded articles such as heat-insulated mats or heat-insulated sheets, which are practically applied based on the proposed patent, are easily formed and separated from the molded body due to their low stability even after the silica aerogel is formed in a form suitable for use or the silica aerogel is embedded in the molded body. Since the silica airgel is ultra fine and ultra light, it causes severe scattering when separated from the composition, causing serious work pollution during thermal insulation installation work.

Therefore, the silica airgel should not be separated from the molded body as much as possible. In fact, when the silica airgel is in the form of powder, it is very difficult to stably contain it in the molded body such as mat by using the powder state as it is only nanometer level. . The presently proposed molded articles such as insulation mats containing silica aerogels are contained in glass fibers or carbon fiber nonwoven fabrics during the drying process of silica aerogels, and are manufactured as a heat insulating body and a heat insulator, thereby avoiding the separation of the fine powder. In fact, when the insulation construction work using these insulation mats, the silica airgel is scattered and sticks to the skin, causing severe skin irritation, and in severe cases, it can cause skin disease. Situation.

On the other hand, the proposed method of shaping the molded body in the form of a mass is also a method to use the silica aerogel filled in the mold or structure not leaked, which can solve the problem of forming the molded product in the form of the existing products as described above It may be a plan, but it is difficult to expect practical use due to the lack of convenience.

In addition, as in the case of existing thermal insulation mats and thermal insulation sheets, the production of thermal insulation mats by attaching nanometer-sized silica aerogel particles to the surface of a fibrous substrate or incorporating them into a molded body is inherent in the molded body because the silica aerogel is ultra light and ultra fine. Not only is it difficult to control the amount of the material to be uniformly dispersed in the fibrous mat, so that the local thermal conductivity in the finally produced insulation mat, there is a disadvantage that the product performance is not uniform at every production.

Therefore, ultra-light and ultra-fine silica aerogels expressing the function of thermal insulation are not separated or separated from the molded body, and a certain amount of silica aerogel powder is injected into the insulation, and the insulation sheet and the insulation mat are uniformly dispersed in the insulation mat. Alternatively, the invention of the insulating molded article having a desired form and a method of manufacturing the same is a very urgent problem in the related industry.

The present invention is to solve the conventional problems as described above, an object of the present invention is to quantitatively injected into a molded article of a thermal insulation function, such as a thermal insulation sheet, a thermal insulation mat of various sizes of nano-sized powder having a thermal insulation performance, such as silica airgel In addition, it is possible to uniformly disperse the thermal insulation performance in the thermal insulation mat, so that the ultra-fine powder such as silica aerogel expressing the thermal insulation performance is separated and separated from the thermal insulation molding such as the thermal insulation sheet and the thermal insulation mat. Or to provide a way to manufacture a thermal insulation sheet, a thermal insulation mat or a related type of insulation molded without escape scattering.

A feature of the present invention for achieving the above object is, theoretically, a heat insulating sheet ultra-fine powder having a size of several nanometers or less, in particular aerogel, more specifically, silica aerogel, etc. , Meshes with pores smaller than the size of these ultrafine particles, which are uniformly contained in the insulating mat or the required shaped body, and which can contain these ultrafine particles in order to be contained stably without being separated from these shaped bodies. There is a need for a conjugate having a structure, and in the present invention, a nanofiber having a diameter of several nanometers is used, and a network of fiber cloth having pores smaller than the size of a silica aerogel in which the nanofibers are to be embedded is made. To achieve the desired purpose by laminating All.

In the present invention, the production of nanofibers basically uses the principle of electrospinning to produce nanofibers by applying a high voltage to a polymer solution or a melt to induce a polymer jet. That is, in the present invention, the nano-sized silica aerogel, which is a thermally insulating ultra-fine powder, is mixed in a polymer solution, and the silica aerogel is entrained in the process of spinning the polymer material by electrospinning. Silica airgel is to be uniformly embedded in the air. And in this case, the conditions of the nanofiber spinning to control the size of the diameter of the nanofibers prepared, and the size of the mesh formed on the nanofiber cloth is made smaller than the size of the silica aerogel particles theoretically, the object of the present invention Can be achieved.

According to the present invention, in order to achieve the means of the present invention according to this process, the silica aerogel, which is primarily an ultrafine particle of adiabatic expression, should be uniformly dispersed in the polymer material for spinning, and the nano fine particle powder It is not easy to uniformly introduce into the polymer materials with enormous size difference, and since silica aerogels are extremely low due to their ultra-light weight, they are dissolved in a solvent and then made into a liquid phase and mixed directly. Even if mixed with the polymer is not easy. Therefore, after impregnating and dispersing the silica aerogel in a solvent, it is easy to process the silica aerogel impregnated and dispersed in the solvent into the polymer resin material. In particular, since silica aerogels have strong hydrophobicity, the dispersion itself is almost impossible in water or polar solvents, and solvents in which silica aerogels may be accompanied by chemical reactions with polymer resins are also impossible. The silica aerogel, once impregnated in an organic solvent, is not a problem because the polymer resin can be easily dispersed and mixed on the polymer resin when the polymer resin is in a liquid state or dissolved in another solvent and becomes liquid. It does not matter even if the solvent in which the airgel is dispersed can dissolve the solid polymer resin. However, when the solid resin is melted for spinning, when the boiling point of the solvent impregnated and dispersed in the silica aerogel is lower than the melting temperature for spinning the solid resin, the solvent in which the silica aerogel is dispersed before the spinning of the resin for nanofiber production As it volatilizes, the dispersion efficiency of the silica aerogel in the solid polymer resin is reduced, and in severe cases, the separation from the polymer resin is caused. Therefore, the selection of a suitable solvent to impregnate and uniformly disperse the silica aerogels is very important. In the present invention, a variety of nonpolar solvents are used, including n-Hexane, Cyclohexane, DMF, p-Xylene, toluene, and the like.

According to the present invention, a thermally insulating sheet, a thermally insulating mat, or a related type of thermally insulating sheet, in which the silica aerogel, which is an ultrafine powder having thermal insulation performance, is uniformly dispersed and separated or separated from the thermally insulating body such as an insulating mat containing a certain amount, is not dispersed. It is obtained through the same process. That is, this manufacturing method is

Impregnating the ultra-fine powder, more specifically, silica aerogel, which exhibits adiabatic properties, with the organic solvent in a weight ratio of 0.01 to 10 weight ratio, based on the weight ratio of the organic solvent (step 1-1);

Modifying the surface properties of the silica aerogel impregnated with an organic solvent (step 1-2);

In order to maintain a constant viscosity required for nanospinning the silica aerogel impregnated with the organic solvent, a predetermined amount is introduced into the liquid polymer resin material and mixed uniformly (Step 2-1), or the silica aerogel impregnated with the organic solvent Mixing uniformly by introducing a predetermined amount into the molten polymer resin material by heating so as to maintain a constant viscosity required during nanospinning (step 2-2);

Preparing a sheet or a mat by laminating the silica aerogel together with the nanofibers so as not to be separated from the nanofibers by preparing nanofibers from the polymer resin material containing the silica aerogels uniformly (step 3);

Drying the silica aerogel in the nanofiber spinning cloth in which the nanofibers are laminated to remove the organic solvent in the silica aerogel (step 4); And

Insulating ultrafine powder, characterized in that it comprises a step (5 steps) of heat-treating the nanofiber radiation cloth in which the silica aerogel obtained by the above step 4 is embedded in accordance with the purpose of various purposes, such as low temperature or high temperature conditions, specifically Silica aerogel is a method of manufacturing a heat insulating sheet, a heat insulating mat or a heat insulating molded article is not separated and separated.

In the present invention, the heat-insulating fine powder required for preparing the heat-insulating mat will be described for the sake of convenience of the silica aerogel, but this is only a preferable example, and the heat-insulating fine powder should not be construed as being limited to the silica aerogel in the present invention. The present invention, for example, in addition to the silica aerogel as the ultra fine powder, metal carbide aerogels, carbon aerogels, inorganic aerogels such as alumina aerogels, organic aerogels such as polyimide aerogels, porous silica, porous calcite, porous pearlite, porous glass, porous magnesia, Mineral ultrafine powders such as porous basalt can also be used.

Impregnating the appropriate organic solvent in the thermally insulating powder, more specifically, the pores of the silica aerogel in step 1-1, promotes homogeneous dispersion, and as described above, destroys the structure of the silica aerogel during drying and heat treatment. This is to prevent the loss of thermal insulation properties. For this purpose, non-polar organic solvents having no -OH groups such as n-hexane, cyclohexane, DMF, and p-Xylene are preferred, but silica impregnated as described above in a subsequent step following step 1-2 of the present invention. Various organic solvents may be used in which the aerogels are separated or agglomerated from the polymer resin or react with a solvent in which the solid polymer resin is dissolved. The amount of silica air gel to be impregnated may be used in a weight ratio of 0.01 to 10 as a weight ratio with respect to the organic solvent. Preferably, the silica air gel is impregnated with the organic solvent to maintain a flowing sludge and mix well with the polymer resin material. It is appropriate enough. Even if the amount of silica aerogel is less than 0.01 weight ratio with respect to the organic solvent, it does not cause a big problem, but the amount of the silica aerogel to be present in the sheet, mat or molded product to be finally produced may lower the thermal insulation and thermal insulation function. In this condition, since an excessive amount of solvent is used, using an excess amount of an organic solvent is not preferable in terms of economic and environmental aspects because it needs to be dried and removed after nanospinning in the future. If the ratio is 10 weight ratio or more, the viscosity of the whole raw material consisting of silica aerogel, a solvent containing silica aerogel, and a polymer resin becomes too high, making it difficult to supply the raw material toward the raw material outlet during nanospinning.

The purpose of surface modification of the silica aerogel in the 1-2 process is to prevent loss of thermal insulation properties due to structural destruction of the silica aerogel during drying and heat treatment from the spinning process as in the 1-1 process. More specifically, when the silica aerogel contained in the nanofiber lamination has low purity or poor drying treatment in the manufacturing process of the silica aerogel, and moisture or -OH groups remain in the silica aerogel, the spinning process may be performed during the nanofiber manufacturing. This is because pores of the silica aerogel may shrink or break due to evaporation of moisture or reaction between these -OH groups during drying and heat treatment. Therefore, there may be a difference depending on the manufacturing process of the silica airgel, but the surface modification process of 1-2 is high purity and well dried so that the process of 1-1 when using the silica airgel without -OH group in the silica airgel It should be understood as an alternative process because it alone can achieve its purpose. For this surface modification, various types of organosilane compounds such as chromosilane, methylchlorosilane, dimethylchlorosilane and trimethylmethylsilane may be used, and trimethylchlorosilane is preferable. Do. The reason for using such an organosilane compound for surface modification is that these compounds combine with -OH groups by coupling with -OH groups to form -OH groups. This is because the pore breakage of silica airgel can be blocked.

Steps 2-1 and 2-2 are a process of mixing a silica aerogel impregnated with an organic solvent and a polymer resin material, which is a material to be nanofibers after spinning, depending on the characteristics of the polymer resin material to be spun. The process proceeds to either one of steps 2-2.

That is, step 2-1 may be selected when the polymer resin material to be spun into nanofibers is dissolved by an appropriate solvent so that the polymer resin material may be in a liquid phase, and step 2-2 is polymer resin material to be spun into nanofibers. This is a case where a solvent capable of dissolving is not suitable and used to melt the polymer resin material by heating. Therefore, in the case of the 2-2 process, since the melting temperature of the polymer resin material to be heated and made liquid for nanospinning is high, the organic solvent impregnated into the silica aerogel in the process 1-1 also has a boiling point higher than the melting temperature of the polymer resin material. The choice of an appropriate organic solvent, which is not low, is important. In addition, the solvent for dissolving the polymer resin material in step 2-1 may use the same organic solvent as the organic solvent impregnated with the silica aerogel in step 1, and may use another solvent. However, when a different solvent is used, a physicochemical reaction may occur. It is preferable to use the same nonpolar solvent as much as possible.

The third step is a process in which the silica airgel is charged and dispersed between the lamination of the nanofibers while the nanofibers are prepared by electrospinning the polymer resin material containing the silica aerogel.

The electrospinning process system is largely composed of three areas: a supply discharge part for supplying a polymer resin material, a high voltage forming part for applying a voltage, and a collector for stacking nanofibers. Silica airgel can be charged between the stacked nanofibers because the silica airgel is an ultra-lightweight and nanometer-sized micropowder, which is a dust collecting part for stacking nanofibers from the discharge part supplied with the polymer resin material during the electrospinning process. This is possible because silica aerogels can be entrained in the course of migration.

The nanofiber manufacturing process by electrospinning is a rheological variable such as molecular weight of polymer resin, molecular type, concentration of solution polymerized polymer, viscosity of polymer resin in solution, dielectric constant, etc. Voltage, flow rate, distance between tip and collector, moving speed of collector, etc., and ambient temperature and humidity are also important variables. Therefore, the optimum conditions of these parameters will be determined by the ratio of the organic solvent impregnated with the silica aerogel used, the concentration of the polymer resin to the organic solvent and its viscosity. In the present invention, a mixture of a polymer resin material dissolved in an organic solvent in which a silica aerogel impregnated with an organic solvent mixed according to the steps 1-1, 1-2 and 2-1 and 2-2 is dissolved in a polymer resin. One full mixture (hereinafter referred to as "radioactive material mixture") is charged to the supply discharge of the electrospinning system and spun under a condition of 1,000 to 100,000 Volt to produce and laminate nanofibers so that the silica airgel does not separate from the mat. do. Voltage conditions can be widely determined depending on the type of polymer resin to be nanospun. If the voltage is less than 1,000Volt, nano-radiation is not easy due to the low electric field, and more than 100,000Volt can not expect any further effect considering the polymer resin used so far. In addition, the composition and the resulting viscosity of the raw material mixture is important because it depends on the diameter of the nanofibers and the pores of the laminated nanospun cloth. Depending on their composition ratio, the viscosity can be determined as a whole, and the viscosity is appropriate to contain silica aerogel in the nanospun fabric and not to be separated while maintaining droplets while the droplets are radiated at the distal end of the supply discharge. Can be a condition. In the case of heating and melting the polymer resin material for this spinning process, the viscosity of the raw material mixture may vary depending on temperature, and the viscosity may be adjusted by adding a heating temperature or an organic solvent. In addition, the specific viscosity may also vary depending on the diameter of the discharge port.

In the present invention, since the spinning method applicable to various polymer resin materials may be used as a method for producing nanofibers, the present invention should not be construed as being limited to the electrospinning method as a specific type of nanofiber spinning method, and the present invention. As a spinning method of silver nanofibers, it can be applied to other nanofiber manufacturing methods such as multi-division method, flash method and melt blown method.

In addition, in the present invention, nanofibers made of polypropylene (PP), polyacrylonitrile (PAN), PVA and silica resin, etc. are used in the present invention, but the present invention is limited to a specific type of polymer resin material. It should not be construed as. Materials capable of producing nanofibers that can be applied to the concepts of the present invention include glass fiber, quartz, polystyrene, polybutylene, polystyrene, polyester (PET), polyethylene, polybenzimidazole (PBI), polyphenylbenzo Bisoxazoles (PBO), polyetheretherkedones (PEEK), polyallylates, polyacrylates, polytetrafluoroepylenes (PTFE), polyylmethaphenylenediamines (Nomex), poly-paraphenylene terephthalamides (Kevlar), ultra high molecular weight polyethylene (UHMWPE), phenol resin, nobleoid resin (Kynol), carbon fiber, etc. may also be a raw material for the production of nanofibers.

The fourth step is a step of restoring the thermal insulation properties of the silica aerogel by drying the silica aerogel contained in the nanofiber spinning cloth laminated by the three steps to remove the organic solvent impregnated in the silica aerogel. This drying step is carried out in the first step if the boiling point of the organic solvent impregnated in the silica aerogel or the solvent for dissolving the polymer resin material is different from the organic solvent impregnated in the silica aerogel, the first drying at different temperatures depending on the boiling point of the solvent You can proceed. More specifically, when the solvent impregnated in the silica aerogel and the dissolving solvent of the polymer resin use the same n-nucleic acid, the drying process may restore the silica aerogel to its original state even at room temperature for about 48 hours. At a temperature of ° C, more preferably, about 24 hours in an atmosphere of water blocked under the condition of 60 ° C is restored to the characteristics of the silica aerogel.

The fifth step is a step for maximizing the porosity of the silica aerogel contained in the silica aerogel-containing nanofiber spinning cloth obtained through the four steps. In some cases, the insulating mat can be obtained by only following the above four steps according to the intended use, but by improving the porosity of the silica aerogel contained in the lamination of the nanofiber cloth, the performance of the insulating mat can be improved. In addition, by thermally decomposing the nanofibrillated polymer material into high heat resistant fibers, a high temperature insulation mat usable at high temperatures may be manufactured. The heat treatment conditions such as decomposition temperature, heating duration, temperature rising condition and cooling, which are the conditions of the pyrolysis, depend on the type of the polymer material selected. However, the maximum temperature of the heat treatment conditions can not be applied at a temperature where the structure of the airgel can be destroyed, for example, a temperature of 800 ℃ or more in the case of silica airgel.

Impregnating silica airgel in one step according to the use and application target of the heat insulating sheet or the heat insulating mat in the method of manufacturing a heat insulating sheet or heat-insulating mat that does not separate the silica air gel, and more specifically the above-mentioned heat-insulating properties. The characteristics of organic solvents are different, and the types of polymer resins are different in steps 2-1 and 2-1. The type of organic solvent also varies depending on the type of polymer resin. For example, it is preferable to melt PP, but p-Xylene may be used as a solvent.

They also differ in the organic solvent, depending on how the resin is introduced in the three-spinning process. More specifically, when dissolving the resin as a solvent in order to introduce the polymer resin in the spinning process in three steps, a low boiling point solvent may be used as the solvent used in the first step, but a heat melting method is applied to introduce the polymer resin. In the case of the solvent used in the first step, a solvent whose boiling point is higher than the melting point of the polymer resin or less is to be used. When the heating melting method is used to introduce the polymer resin, when the solvent used in one step is used as an organic solvent having a low boiling point, the organic solvent impregnated in the silica aerogel is evaporated and separation of the silica aerogel and the polymer resin occurs. Therefore, the uniformity of the distribution of the silica aerogels in the stack of the nanofibers may be reduced, which may cause local thermal conductivity deviations in the finally produced insulating mat.

According to the manufacturing method of the insulating sheet or the insulating mat according to the present invention, the ultra-fine particles having a high thermal insulation properties, more specifically, the ultra-fine particles of the nanometer level, such as silica aerogel having a very low thermal conductivity Even if the silica aerogel is separated or separated from the sheet, mat or the desired molded body does not occur. Therefore, when fabricating various molded articles for the purpose of thermal insulation using sheet or mat material exhibiting such heat insulating properties, serious work contamination due to scattering of nano-sized silica aerogel from the nanofiber substrate or scattering due to the separation is fundamental. As well as being blocked, according to the choice of the polymer resin that is the raw material of the nano-radiation cloth, the insulation sheet or insulation mat containing silica airgel is used for various purposes such as industrial, construction, contact areas of the human skin such as cold weather clothing, fire fighting suit, shoe insole, etc. It is possible to manufacture breakthrough insulation pads that can be applied to.

1A and 1B are electron micrographs of the nanofiber lamination fabricated by the present invention in which nano-sized airgel particles are dispersed and confined in pores in a nanofiber lamination fabric composed of nanofibers.
Figure 2a is an electron micrograph of a thermal insulation mat in which a silica airgel is inserted into a conventional glass fiber cloth
Figure 2b is an electron micrograph of a thermal insulation mat inserted silica silica gel in a conventional carbon fiber cloth

Hereinafter will be described in detail with reference to the embodiment of the production method of the ultra-fine powder having a heat insulating property according to the present invention, more specifically, a heat insulating mat does not appear phenomenon such as scattering due to the separation or separation of the silica airgel ultra-fine powder. do.

<Example 1>

2.0 g of silica airgel is impregnated with 10 ml of DMF. Then, 1 ml of silane is added to the surface of the silica aerogel. Also, 3.4 g of PAN is completely dissolved in 15 ml of DMF, and the surface modified and silica air gel impregnated with DMF is added to the PAN solution and stirred well to prepare an electrospinning raw material mixture. The viscosity of the raw material mixture before charging to the discharge section of the electrospinning system is maintained so that droplets can be made without exiting the discharge section. While maintaining the voltage at 30,000V, the nanospinning proceeds and the nanofibers are spun off. The thickness of the laminated fabric can be arbitrarily adjusted according to the intended use. When the thickness of the laminated fabric is 0.2 ~ 0.5mm by taking the nano-spun laminated fabric and dried ^at about 160 ^℃ to obtain a heat insulating sheet formed of PAN resin silica silica gel is not separated from the inside of the laminated fabric.

1 is an electron micrograph of the nanofiber fabric prepared in Example 1. As can be seen from this photograph, the nanometer-sized silica aerogel is caught in the pore gap formed in the laminated fabric composed of nanofibers. have.

Figure 2 is an electron micrograph of a prototype insulation mat prepared on the basis of the existing patent containing silica airgel on glass fiber or carbon fiber in order to compare with these results. Existing heat insulating mat in the form as shown in Figure 2 silica aerogel is contained on the surface of the fibrous, such as easily detached from the mat and causes severe scattering phenomenon.

<Example 2>

2.0 g of silica airgel is impregnated with 10 ml of DMF. Then, 1 ml of trimethylchlorosiren is added to the surface of the silica aerogel. Also, 3.5 g of polypropylene resin is completely dissolved in 20 ml of p-Xylene ^at 120 ^{° C.} , and the surface of the polypropylene resin solution is added to the silica aerogel impregnated with DMF and stirred well to prepare an electrospinning raw material mixture. The viscosity of the raw material mixture before charging to the discharge section of the electrospinning system is such that droplets can be produced without exiting the discharge section. The voltage is maintained at 30,000V to proceed with nanospinning and the nanofibers are emitted. The thickness of the laminated fabric can be arbitrarily adjusted according to the intended use. When the thickness of the laminated fabric is 0.2 ~ 0.5mm, the nano-spun laminated fabric is taken and dried for 2 hours at 0.5 atm and 80 ^{° C} to evaporate DMF and p-Xylene and dry first. Then, the temperature was maintained ^at 0.5 atm and 100 ^{° C.} , followed by secondary drying and heat treatment to completely evaporate DMF and p-xylene for 2 hours. Get the mat. When the primary drying is carried out at normal pressure, the temperature is increased, and as a result, thermal damage of the nanospun polymer resin material may occur, and thus the pressure is lowered at a lower pressure than normal pressure.

<Example 3>

2.0 g of silica airgel is impregnated with 5 ml of DMF. Then, 1 ml of trimethyl chlorosiren is added to modify the surface of the silica aerogel. Heat 3.5 g of polypropylene to dissolve it and keep the liquid phase warm. Silica aerogel impregnated with the DMF was added to this liquid polypropylene, followed by stirring sufficiently. In the sludge state, polypropylene containing silica airgel is charged to the discharge part of the electrospinning system to prepare the electrospinning, where the viscosity of the raw material mixture is sufficient to make droplets without flowing out of the discharge part before the electrospinning. Maintain the temperature of the discharge part. The voltage is maintained at 30,000V to proceed with nanospinning and the nanofibers are emitted. The thickness of the laminated fabric can be arbitrarily adjusted according to the intended use. When the thickness of the laminated fabric is 0.2 ~ 0.5mm, the nano-spun laminated fabric is taken and dried at 0.5 atmosphere of 100 ^℃ for 2 hours to evaporate DMF and dry first. Then, the temperature was maintained ^at 0.5 at 12.degree.

<Example 4>

2.0 g of silica airgel is impregnated with 5 ml of DMF. Then, 1 ml of trimethyl chlorosiren is added to modify the surface of the silica aerogel. 3.5 g of PVA and silica are dissolved by heating, and the liquid phase is kept warm. Silica aerogel impregnated with n-hexane is added to this liquid PVA and silica mixed solution, followed by stirring sufficiently. The mixture of PVA and silica containing silica aerogel in the sludge state is charged to the discharge part of the electrospinning system to prepare the electrospinning, and before the electrospinning, the viscosity of the raw material mixture does not flow out of the discharge part to make droplets. Maintain the temperature of the discharge portion as much as possible. The voltage is maintained at 30,000V to proceed with nanospinning and the nanofibers are emitted. The thickness of the laminated fabric can be arbitrarily adjusted according to the intended use. When the thickness of the laminated fabric is 0.2 ~ 0.5mm, the nano-spun laminated fabric is taken and dried at 150 ^{° C.} for 1 hour to evaporate the DMF and dry first. The temperature is again maintained at 18O &^lt; 0 &^gt; ^C and secondary dried for 2 hours to completely evaporate residual DMF. And if the second heat treatment and then dried for 1hr at 500 ^℃ Raise the temperature at a heating rate of 2 ^℃ / min again to obtain a high temperature for the heat insulating mat 500 ^℃ silica airgel is not detached from the inside laminated fabric.

Insulation mat provided in the present invention is not a phenomenon that the ultra-fine powder expressing the thermal insulation properties are scattered by the departure or departure from the mat, various applications and purposes by selecting a polymer material or a material corresponding to the nanofibers Applicable to Specifically, insulation process mats for industrial processes such as thermal insulation mats for chemical processes, thermal insulation mats for low temperature tanks, thermal insulation materials for construction, etc., as well as winter clothing, fire fighting suits, thermal shoes, etc. It can be used as a material.

In the scope of the basic technical spirit of the present invention, many modifications are possible to those skilled in the art, and the scope of the present invention should be interpreted based on the claims which will be described later. .

Claims (16)

As a method of manufacturing a heat insulating sheet, a heat insulating mat or a desired heat insulating molded article in which ultra-fine powder expressing a heat insulating property does not show scattering phenomenon due to detachment or separation,
Method for producing a thermally insulating sheet, a thermally insulating mat, or an insulating molded article in which ultra-fine powder expressing the thermal insulation property is confined in the nanometer-level pores formed by laminating nanofibers to have nanometer-level pores. The method of claim 1, wherein the ultra-fine powder expressing the heat insulating properties is a silica airgel. Impregnating the ultrafine powder expressing the adiabatic property to the nonpolar organic solvent in a ratio of 0.01 to 10% by weight relative to the organic solvent to be impregnated with the ultrafine powder (step 1-1);
Mixing the ultrafine powder impregnated with the organic solvent with the molten polymer resin (step 2);
Nanofibers are prepared from polymer resin mixed with ultra-fine powder and laminated to have nanometer-level pores, and the ultra-fine powder is contained in the nanometer-level pores and laminated together with nanofibers so as not to be separated from the pores. Preparing a nanofiber spinner sheet or mat (3 steps); And
Drying the ultrafine powder in the nanofiber spinning cloth in which the nanofibers are laminated to remove the organic solvent in the ultrafine powder (step 4);
Ultra-fine powder of the expression of heat insulation properties, characterized in that it comprises a method of producing a thermal insulation sheet, a thermal insulation mat or a heat insulating molded article is not scattered due to separation or separation. 4. The method of claim 3, further comprising modifying the surface properties of the ultra-fine powder impregnated with the organic solvent after the step 1-1 (step 1-2). 5. Way. The method of claim 4, further comprising a step (5 step) of heat-treating the nanofiber yarns in which the ultra-fine powder is embedded after the step 4 (5). The method of claim 5, wherein the ultra fine powder is characterized in that any one of silica aerogel, metal carbide aerogel, carbon aerogel, alumina aerogel, polyimide aerogel, porous silica, porous calcite, porous pearlite, porous glass, porous magnesia, porous basalt Method for producing a thermal insulation sheet, thermal insulation mat or insulation molded product. The method of claim 6, wherein the ultra-fine powder is a silica aerogel is more preferable. The method of claim 7, wherein the non-polar organic solvent impregnated with the silica aerogel uses a non-polar organic solvent having no -OH group, including n-hexane, cyclohexane, DMF, and the like. . The method of claim 4, wherein a coupling agent comprising methyltrichlorosiren or TiCl ₄ is used as a surface modifier for surface modification of the ultra fine powder. 8. The polymer resin of claim 7, wherein the polymer resin is nanofibers and contains silica aerogels. Polyacrylonitrile, polypropylene, polyacrylate, polyolefin, polystyrene, polyurethane, polyimide, polyfurfural alcohol, polyvinyl alcohol, polycyanurate Method for producing a heat insulating sheet, a heat insulating mat or a heat insulating molded article, characterized in that any one of the rate, polyacrylamide. The method of manufacturing a heat insulating sheet, a heat insulating mat, or a heat insulating molded product according to claim 3, wherein the nanofiber spinning method is performed by a multi-splitting method, a flash method, a melt blown method, or an electrospinning method. 12. The method of claim 11, wherein the spinning method of the nanofibers is more preferably electrospinning or melt blown method. The method according to claim 11 and 12, characterized in that an electric field of 1,000 ~ 100,000 volts is used as the voltage at the time of electrospinning. The method of claim 7, wherein the molten polymer resin of the second step is a polymer resin melted with an organic solvent or melted by heating a polymer resin. The method according to claim 14, wherein the organic solvent for dissolving the polymer resin is the same solvent as the nonpolar organic solvent impregnated in the ultrafine powder. Insulation sheet, insulating mat, characterized in that the ultra-fine powder of the expression of heat insulating properties contained in the interior of the 3 to 15, characterized in that the ultra-fine powder is not scattered due to detachment or detachment Or thermal insulation.

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