KR20080047150A - Portable information device having aerogel adiabatic sheet - Google Patents

Abstract

A portable information device embedded with an aerogel adiabatic sheet is provided to reduce heat transfer between a heated part and other parts by installing the aerogel adiabatic sheet between the heated part and an external case, between the heated part and an HDD(Hard Disk Drive), and/or between the heated part and an external extension port. An aerogel adiabatic sheet(10) is installed between a heated part and an external case(40,42), between the heated part and an HDD(60), and/or between the heated part and an external extension port(80). The heated part is at least one of a CPU, a GPU(Graphic Processing Unit), a PCB(Printed Circuit Board)(20) mounting the CPU and the GPU, and a power supply unit. The aerogel adiabatic sheet comprises needle punching nonwoven and aerogel particles charged in the needle punching nonwoven. The needle punching nonwoven is laminated by thermal processing.

Description

Portable information device having aerogel adiabatic sheet

1 to 3 is a perspective view showing a notebook computer as a portable information device embedded with an airgel insulating sheet according to a preferred embodiment of the present invention.

4 to 6 is a perspective view showing a mobile phone as a portable information device embedded with an airgel insulating sheet according to a preferred embodiment of the present invention.

Figure 7 is a view showing a side cross-section of the airgel sheet airgel beads filled in the needle punched nonwoven fabric according to an embodiment of the present invention.

8 is a side cross-sectional view of an airgel sheet filled with a needle punched nonwoven fabric of airgel powder according to another embodiment of the present invention.

9 is a side cross-sectional view of an airgel sheet in which airgel beads and powder are filled in a needle punched nonwoven fabric according to another embodiment of the present invention.

FIG. 10 is a side cross-sectional view of an airgel sheet filled with an IR opaque material in a needle punched nonwoven fabric in another embodiment of the present invention.

11 is a side cross-sectional view of an airgel sheet filled with airgel beads in a needle punched nonwoven fabric formed of two layers according to another embodiment of the present invention.

12 is a view showing an airgel sheet manufacturing process used in the embodiment.

13 is an electron micrograph of the cross section of the airgel sheet prepared in Example 9;

FIG. 14A is a side cross-sectional view of a sample cell used in the apparatus for measuring the adiabatic properties of the airgel in Example 12.

14 (b) is a graph showing the heat insulating properties of the airgel sheet measured in Example 12.

<Explanation of symbols for the main parts of the drawings>

10: airgel insulation sheet 11: needle punch nonwoven fabric

12: airgel bead 13: airgel powder

14: IR opaque material 20: printed circuit board

40: keypad case 42: bottom case

60: hard disk drive 80: external expansion terminal

100: notebook 200: mobile phone

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable information device, and more particularly, to a portable information device incorporating an airgel insulating sheet configured to reduce heat transfer between a heat generating unit and another component.

Recently, due to the rapid development of IT technology, portable information devices such as notebook computers, mobile phones, PDAs, and mobile phones are becoming thin, small, light, high functional, and high quality.

As a result, portable information devices become smaller and thinner, and many unit parts required for high functionality and high quality are mounted in a small space.

Here, the importance of the thermal management of the components of the portable information device is gradually increasing. In other words, the portable information device is precise due to the improved performance, and thus generates a lot of heat during operation.

However, due to the miniaturized size, high heat is transmitted from the heat generating part by reducing the separation distance between the heat generating part and the outer case or between the heat generating part and the other parts, thereby degrading the performance of the product and adversely affecting the human body.

That is, heat generated in the heat generating unit inside the portable information device is transferred to the hard disk drive or the external expansion terminal of the notebook computer, which causes a problem that may cause damage and malfunction of the components.

In addition, if heat of a heat generating unit such as a printed circuit board equipped with a CPU in the portable information device is not effectively controlled, heat generated inside the device is transferred to the external case, in which case the external case of the portable information device and the user's body Because heat is delivered to the direct contact area, there is a problem that can cause discomfort to the user, as well as safety accidents when used for a long time.

On the other hand, due to the trend toward miniaturization and thinning of portable information devices, general insulation materials such as glass wool or polyurethane foam for insulation of these information devices are limited in use. That is, since there is an internal space limitation in the portable information device, the insulation performance of the materials is difficult to control the effective insulation as a thin insulation material in the portable information device occurs.

The present invention was devised to solve the above problems, and has excellent thermal insulation performance between at least one of a heating unit and an external case inside the portable information device, between the heating unit and the hard disk drive, and between the heating unit and the external expansion terminal. It is an object of the present invention to provide a portable information device that is configured to reduce the heat transfer by arranging the airgel insulating sheet having a.

In order to achieve the above object, a portable information device according to a preferred embodiment of the present invention has a built-in airgel insulation sheet configured to reduce heat transfer between a heat generating unit and another component.

In this case, the airgel insulating sheet is preferably disposed between at least one of the heating unit and the case, between the heating unit and the hard disk drive (HDD), between the heating unit and the external extension terminal.

The heat generating unit may be one selected from a central processing unit (CPU), a graphics processing unit (GPU), a printed circuit board (PCB) on which the central processing unit and the graphic processing unit are mounted, and a power supply unit.

The airgel insulation sheet, needle punched nonwoven fabric; And airgel particles filled in the needle punching nonwoven fabric.

The airgel insulating sheet, the step of scattering the airgel particles on the needle punched nonwoven web; Preneeling the airgel onto the scattered nonwoven web; Needle punching the pre-needle punched web; And laminating the surface of the needle punched web by heat treatment.

Or, the airgel insulating sheet, the step of scattering the airgel particles on the needle punched nonwoven web; Laminating a needle punched nonwoven web on the scattered airgel; Preneedle punching the laminate of the needle punched nonwoven web; Needle punching the pre-needle punched web; And laminating the surface of the punched web by heat treatment.

1 to 3 is a perspective view showing a notebook computer as a portable information device embedded with an airgel insulating sheet according to a preferred embodiment of the present invention.

Referring to the drawings, the notebook computer 100 has a built-in airgel heat insulating sheet 10 having an excellent heat insulating function, for example, to reduce the heat transfer between the heat generating portion and other components of the notebook computer 100, It is installed between the heat generating portion of the notebook computer 100 and the cases 40 and 42 or other components.

In this case, the heat generating unit may include a central processing unit (CPU), a graphic processing unit (GPU), a printed circuit board on which the central processing unit and the graphic processing unit are mounted. It is preferably one selected from a printed circuit board 20 and a power supply.

Here, the central processing unit may increase the surface temperature to about 100 ℃ when used for a long time.

In particular, FIGS. 1 to 3 illustrate an example in which the heating unit of the notebook computer 100 is the printed circuit board 20.

In the case of Figure 1, the airgel insulating sheet 10 is disposed between the printed circuit board 20 and the case 40, 42 which is a heat generating portion. At this time, the case 40, 42 is composed of a keypad case 40 located on the upper side of the notebook computer 100 and a bottom case 42 located on the lower side.

In addition, in the case of FIG. 2, the airgel insulating sheet 10 is disposed between the printed circuit board 20, which is a heating unit, and the hard disk drive 60, and in the case of FIG. 3, the airgel insulating sheet 10. Shows that the heat generator is disposed between the printed circuit board 20 and the external expansion terminal 80.

On the other hand, Figures 4 to 6 is a perspective view showing a mobile phone 200 as a portable information device with a built-in aerogel insulating sheet according to a preferred embodiment of the present invention.

Referring to the drawings, the mobile phone 200 is a case in which the heat generating unit is a printed circuit board 120, like the notebook computer 100, and the aerogel heat insulating sheet 10 having excellent heat insulating functions is a printed circuit board 120. ) And between the case 140 and 142, between the printed circuit board 120 and the hard disk drive 160, and between the printed circuit board 120 and the external extension terminal 180.

In addition, the portable information device 100, 200 of the present invention, the airgel heat insulating sheet 10 as shown in the drawing between the heat generating portion and the case 40, 42, 140, 142, respectively, the heat generating portion and the hard disk It is not limited to being disposed between one of the drives 60 and 160 and between the heat generating unit and the external expansion terminal 80 and 180, and may be disposed to two or both selected from the group.

As a result, according to the present invention, between the heat generating unit and the case 40, 42, 140, 142 inside the portable information device 100, 200, between the heat generating unit and the hard disk drive 60, 160 And the airgel insulating sheet 10 having excellent heat insulating performance between at least one of the heat generating part and the external extension terminals 80 and 180 to reduce heat transfer, thereby preventing damage and malfunction of components. In addition, it prevents safety accidents that can occur to the user when used for a long time, and can effectively control insulation as a thin-walled insulation in a small internal space.

7 to 11 is a view showing a side cross-section of the airgel insulating sheet according to an embodiment of the present invention. As shown in FIGS. 7 to 11, the airgel insulating sheet 10 of the present invention may be a needle punched nonwoven fabric 11 and airgel particles filled in the needle punched nonwoven fabric, for example, an airgel bead 12 and / or an airgel. Powder 13.

The type and physical properties of the needle punched nonwoven fabric filled with the airgel particles are not particularly limited.

The short fibers used in the needle punched nonwoven fabric may be made of a composite fiber including two or more kinds of polymers having different melting points. In the case where a needle punched nonwoven fabric made of a composite fiber is used, it is preferable in that it can be laminated by heating to a melting point temperature of a fiber having a low melting point among two composite fibers when laminating by heat treatment.

The composite fiber is also called conjugated yarn, and is made by extruding polymer materials having two different components from the same spinneret. The cross section of the fiber shows a structure in which the two components are joined in two layers.

The form of the composite fiber is typically a side-by-side (sheath-core), etc., but is not limited thereto. In the present invention, it is preferable that the composite fiber contains two or more kinds of polymers selected from the group consisting of polyester, polyamide and polyolefin.

More preferably, the composite fiber includes polyethylene terephthalate (PET) and a polyolefin-based polymer having a lower melting point than that of the PET. The polyolefin-based polymer is most preferably polyethylene or polypropylene. On the other hand, in the field where heat resistance is required, it is more preferable to include polyester-based fibers.

Furthermore, the composite fiber used in the present invention may have a non-circular shaped cross section, such as a circle or a triangle, an ellipse, a star, or the like.

In the airgel heat insulating sheet of the present invention, the higher the content of the airgel shows excellent heat insulating properties, in the present invention, the airgel particles 10-90wt%, preferably 30-70wt% based on the total weight of the airgel heat insulating sheet It is desirable to be filled in a punched nonwoven. If the airgel content is less than 10wt%, the heat insulating property is lowered, and it is not preferable. If the airgel content is more than 90wt%, it is not preferable in terms of processing difficulty and product strength.

In the present invention, the physical properties, the form, and the manufacturing method of the airgel filled in the needle punching nonwoven fabric are not particularly limited, and any airgel generally known may be used. Although not limited to this, airgel particles having a diameter of approximately sub μm (less than 1 μm) to several mm in size, specifically, an average particle diameter of about sub μm-5 mm may be used. This is the size of the aerogels generally obtained in the preparation of aerogels.

In addition, the density of the airgel affects the thermal conductivity and processability of the airgel, and it is preferable to use an airgel having a density of about 0.01-0.5 g / cm 3. If the density is less than about 0.01 g / cm 3, the particle filling rate is not preferable because of the difficulty in processing, and an airgel having a density of more than 0.5 g / cm 3 may not be preferable because of its low thermal insulation property.

Furthermore, it is preferable to use an airgel hydrophobically treated as airgel particles. In the present invention, as the airgel, in particular, water glass or alkoxy silane is prepared as a raw material, a surface hydrophobized by a silyl group may be used.

Hydrophobic treatment of the surface of the airgel is a silylation treatment, represented by the formula R _{1 4-n-} SiX _n or R ₃ Si-O-SiR ₃ , where n is 1-3 and R ₁ is C ₁ -C ₁₀ , preferably C ₁ -C ₅ alkyl or aromatic, heteroaromatic alkyl Or hydrogen, X is a halogen element selected from F, Cl, Br, I, preferably Cl or an alkoxy group of C ₁ -C ₁₀ , preferably C ₁ -C ₅ , or an aromatic alkoxy group, heteroaromatic An alkoxy group, R ₃ groups are the same or different and C ₁ -C ₁₀ Preference is given to using silica airgel particles hydrophobized with silylating agents of alkyl or aromatic alkyl, heteroaromatic alkyl or hydrogen).

Specific examples of the silylating agent include, but are not limited to, hexamethyldisilane, ethyltrimethoxysilane, ethyltriethoxysilane, triethylethoxysilane, trimethylethoxysilane, methyltrimethoxysilane, ethyltrimeth At least one kind selected from the group consisting of methoxysilane, methoxytrimethylsilane, trimethylchlorosilane and triethylchlorosilane may be used.

In addition, the hydrophobic surface-modified airgel used in the airgel heat insulating sheet of the present invention is not limited thereto, but is hydrophobic surface by the method of Korean Patent Application No. 10-2006-87884 or Korean Patent Application No. 10-2006-98634 Modified airgel particles or powders can be used.

For example, the hydrophobically surface-modified airgel particles may be added with water silicate (sodium silicate) to HCl at 30-90 ° C. until pH 3-5, as described in Korean Patent Application No. 2006-87884. After the silica gel was formed under acidic conditions of pH 3-5, the formed silica gel was washed with distilled water and filtered, and then the surface of the silica gel was silylated, and the surface silylated silica gel was solvented with n-butanol. Substitution may be performed by simultaneously removing the moisture and the reaction residue in the silica gel and drying the silica gel.

In addition, the hydrophobic surface-modified airgel particles may be prepared by the method described in Korean Patent Application No. 10-2006-98634. That is, water silica (sodium silicate) is added to HCl at 30-90 ° C. until pH 3-5 is formed to form silica gel under acidic condition of pH 3-5, and then the formed silica gel is distilled water using a mixer. Wash and filter. Meanwhile, a silylating agent solvent diluted with butanol is prepared, and the washed and filtered silica gel is brought to pH 1-5 using an acid selected from hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid, and thus silyl diluted with the prepared butanol. It can be prepared by adding a solvent to the silylation and solvent substitution process at the same time, followed by drying the silica gel.

In the flexible airgel insulating sheet according to the present invention, an airgel is filled in a needle punch nonwoven fabric, and the airgel may be filled with airgel beads and / or airgel powder. FIG. 7 is a side cross-sectional view of the airgel insulating sheet 10 in which the needle punch nonwoven fabric 11 is filled with the airgel beads 12. 8 is a side cross-sectional view of the airgel insulating sheet 10 filled with the airgel powder 13 in the needle punch nonwoven fabric 11 according to another embodiment of the present invention.

In another embodiment of the present invention, when the needle punch nonwoven fabric is filled with an airgel having a large particle diameter and an airgel having a small particle diameter, for example, an airgel bead and an airgel powder, the pores of the airgel beads having a large particle size have a small particle size. Since the airgel powder is filled, it is possible to increase the filling degree of the airgel particles. 9 is a side cross-sectional view showing an airgel insulating sheet 10 filled with an airgel bead 12 and an airgel powder 13 in a needle punch nonwoven fabric 11 according to another embodiment of the present invention.

Further, by filling the needle punch non-woven fabric with an IR opaque material (block) together to block heat transfer by radiation, it is possible to further strengthen the thermal insulation of the airgel thermal insulation sheet, the air opaque sheet 14 filled with IR opaque material (10) A cross-sectional side view of the cross-section is shown in FIG. As an IR opaque material, it is not limited to this, for example, carbon black, titanium dioxide, iron oxide or zirconium dioxide, or a mixture thereof can be used.

Furthermore, the airgel heat insulating sheet of the present invention can be used by making an airgel heat insulating sheet laminated in two or more layers as necessary. The number of laminations of the airgel insulation sheet is not particularly limited, and for example, the airgel insulation sheet of the present invention is manufactured to a thickness of about 1-10 mm, and laminated to the thickness required in the application where such airgel insulation sheet is used. Can be used.

11 shows an airgel heat insulating sheet 10 having two airgel layers. The laminated airgel insulation sheet may be prepared by manufacturing an airgel insulation sheet having a single airgel layer or an airgel insulation sheet having a plurality of airgel layers, and then laminating them, or alternately laminating a needle punch nonwoven fabric and an airgel layer. have. In the laminated airgel insulating sheet, airgel particles may be used in one layer and airgel powder in the other layer.

In addition, the needle punched nonwoven fabric is laminated on the surface of the heat to prevent the airgel inside is separated to the outside.

In the present invention, "laminating" means that only the fibers present on the surface of the nonwoven fabric is melt-fixed to form a three-dimensional network structure. The laminating may be performed using a device such as, for example, a "flat-bed laminating machine", but is not limited thereto.

Furthermore, the surface protection sheet is laminated in one layer or two or more layers on one or both surfaces of the flexible airgel insulating sheet according to the present invention, thereby preventing the airgel insulating sheet surface from being damaged by external force.

The surface protective sheet may be a nonwoven fabric, a film or a foam, and the like. The surface protective sheet may be one that is generally known, and a particular kind and physical properties are not particularly limited.

Furthermore, one or both sides of the flexible airgel insulating sheet may be water repellent, coated and / or sealed as necessary.

In the airgel insulating sheet used in the present invention, after scattering the airgel particles on the needle punched nonwoven web, the pre-needle punching and bone needle punching of the airgel-scattered nonwoven web and heat-treating the surface of the punched web It can be prepared by a method of manufacturing a flexible airgel insulating sheet for laminating.

Further, the flexible airgel insulating sheet is to scatter the airgel particles on the needle punched nonwoven web, then to laminate the needle punched nonwoven web on the airgel particle layer, preliminary needle punching and bone needle punching, the surface of the punched web It can be produced by laminating by heat treatment.

By additionally laminating the needle punched nonwoven web on the airgel particle layer, the airgel filling rate and mechanical strength of the airgel insulation sheet can be increased, and when used as a product, there is an advantage of reducing the durability reduction due to particle loss of the airgel insulation sheet.

Such a method for manufacturing an aerogel insulation sheet is referred to as a 'direct loaded carded web process'.

Since the needle punch nonwoven web is difficult to achieve a desired level of basis weight at a time in the forming step, it is preferable that the needle punch nonwoven web is manufactured by a cross lapping method in which the web is laminated several times by changing the lamination direction of the web. The needle punch nonwoven web may be made of one type of fiber or two types of composite fibers as described above.

The needle punch nonwoven fabric has a large space between the fibers by carding the airgel particles so that the airgel particles can be easily accommodated, and a nonwoven fabric having a fiber pillar formed by needle punching is used.

The airgel particles in the needlepunch nonwoven web are scattered at 10-90% by weight, preferably 30-70% by weight, based on the total weight of the airgel insulation sheet. If the airgel content is less than 10wt%, the heat insulating property is lowered, and it is not preferable. If the airgel content is more than 90wt%, it is not preferable in terms of processing difficulty and product strength. As the airgel, an airgel as described in the above-described flexible airgel insulating sheet may be used.

Preliminary needle punching step is to entangle in the thickness direction to facilitate the transfer of the scattered web of the airgel, the other needle in the airgel particle layer of the scattered nonwoven web or airgel particles scattered non-woven web After laminating the punched nonwoven web, it is pre-needle punched. The preliminary needle punching process is preferably treated at 50 stroke / min to 300 stroke / min so as to have sufficient tension in web feeding.

The needle punching of the pre-needle punched web allows the fibers and airgel particles of the nonwoven fabric or the nonwoven fabric of the upper and lower layers to be sufficiently kneaded and simultaneously immobilized. The needle punching process is preferably treated at 100 stroke / min to 500 stroke / min so that the fibers and airgel particles are sufficiently kneaded and fully immobilized.

In addition, the surface of the needle punched web may be laminated by heat treatment to prevent airgel particles from being separated from the nonwoven surface layer. The laminating is a surface treatment in order to prevent the airgel particles contained in the nonwoven fabric out of the outside, it is preferable to be treated according to the traveling speed of the nonwoven web at a temperature of 120 to 250 ℃. If it is less than 120 ° C., lamination may not be performed completely, and thus airgel particles may come out of the nonwoven fabric surface layer. If the temperature exceeds 250 ° C., the nonwoven fabric surface layer may be over-fused to damage the surface.

As for the laminating, it is more preferable to use a belt-type laminating apparatus in order to preserve the form of the nonwoven fabric.

On the other hand, by laminating as described above, the airgel particles are fused between one or two layers of the needle punched nonwoven fabrics with or without a separate needle punched nonwoven fabric on the airgel particle layer, as shown in FIGS. 7 to 9. One airgel insulating sheet 10 may be prepared. As described above, the airgel insulating sheet of FIG. 10 by scattering the airgel particles having different particle diameters, for example, airgel beads and / or powders, as well as IR opacifying agents together with the airgel particles on the needle punched nonwoven fabric. It can be manufactured as (10).

Furthermore, as described above, the airgel heat insulating sheet of the present invention may be a laminated form in which two or more airgel particle layers and a nonwoven fabric are alternately stacked, which is prepared after the airgel heat insulating sheet having a single layer or several layers of airgel particle layers is prepared. It may be prepared by laminating or sequentially laminating a needle punched nonwoven fabric and an airgel particle layer. When composed of multiple layers, the particle size of the airgel constituting the airgel particle layer and the inclusion of IR opaque material may be different, and the needle punching nonwoven fabric is also the same or different when the multiple layers are used. Can be.

The airgel insulation sheet thus prepared may be used by bending as it is, or may be used as an airgel insulation sheet in combination with other types of nonwoven fabric as needed.

As described above, the flexible airgel insulating sheet is filled with airgel particles between the interposed pores formed by needle punching. Thus, unlike the conventional technology of using a binder when manufacturing an airgel insulating sheet, an airgel insulating sheet is manufactured without a separate binder. can do. Since a separate adhesive is not used, the blockage of the airgel nanoporosity is prevented when forming the aerogel insulation sheet or the composite due to the use of a conventional adhesive. In addition, since the airgel particles are separately manufactured and filled in the needle punched nonwoven fabric, the gelation and supercritical drying process together with the fiber are not required as in the conventional wet process, thereby making the process simple and inexpensive.

In addition, the airgel thermal insulation sheet is a nonwoven fabric formed by needle punching, the airgel particles are firmly fixed in the nonwoven fabric, even if a separate binder is not used, and the upper and lower layers of the needlepunch nonwoven fabric When is used, the upper and lower layers of nonwoven are firmly attached by needle punching. In addition, needle punching allows the airgel insulation sheet to withstand pressure and load, thereby preventing deformation of the airgel insulation sheet due to breakage of the airgel during use that may occur in the conventional airgel insulation sheet.

Furthermore, the airgel insulating sheet according to the present invention exhibits excellent heat insulating properties, and exhibits thermal conductivity of 40 mW / mk or less, and thus can be used in the portable information device of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples do not limit the present invention.

Example  1: hydrophobic with water glass Surface modified Airgel  Produce

To 1 L of 1N hydrochloric acid solution at 60 ° C, water glass solution (a solution of 35% sodium silicate solution diluted three times with water) is added with a little stirring until pH 4. At this time, the temperature of the reactor is 60 ℃, the reaction was stirred for 2 hours under acidic conditions of pH 4 to prepare a wet silica gel. The wet gel thus prepared is sufficiently washed after being washed several times with a sufficient amount of distilled water to remove Na ions present in the gel. Subsequently, 400 g of the silica wet gel was immersed in 500 ml of diluted silane solution mixed with 90% by weight of methanol (MeOH) and 10% by weight of hexamethyl-di-silane (HMDS), and then refluxed at 120 to 150 ° C for 4 hours. reflux) to modify the airgel surface hydrophobicly. Thereafter, 400 g of the surface-modified silica gel was immersed in 500 ml of n-butanol and refluxed again at 120 to 150 ° C. for 4 hours to remove water in the gel through solvent replacement. The wet gel from which water was removed by solvent treatment was dried at 120 ° C. for 2 hours. The hydrophobic surface-modified airgel thus prepared had a thermal conductivity of 9 mW / m · K. The prepared airgel had a particle size of about 0.3 μm to 500 mm and a density of about 0.03 to 0.04 g / cm 3.

Example  2: hydrophobic with water glass Surface modified Airgel  Produce

A surface-modified airgel was prepared in the same manner as in Example 1 except that ethyltriethoxysilane (ETES) was used as the surface modifier. The hydrophobic surface-modified airgel thus prepared had a thermal conductivity of 11 mW / m · K. The prepared airgel had a particle size of about 0.3 um to 500 mm and a density of about 0.03 to 0.04 g / cm 3.

Example  3: hydrophobic with water glass Surface modified Airgel  Produce

A surface-modified airgel was prepared in the same manner as in Example 1 except that ethyltrimethoxysilane (ETMS) was used as the surface modifier. The hydrophobic surface-modified airgel thus prepared had a thermal conductivity of 11 mW / m · K. The prepared airgel had a particle size of about 0.3 um to 500 mm and a density of about 0.03 to 0.04 g / cm 3.

Example  4: hydrophobic with water glass Surface modified Airgel  Produce

A surface-modified airgel was prepared in the same manner as in Example 1 except that ethyltriethoxysilane (ETES) was used as the surface modifier. The hydrophobic surface-modified airgel thus prepared had a thermal conductivity of 11 mW / m · K. The prepared airgel had a particle size of about 0.3 um to 500 mm and a density of about 0.03 to 0.04 g / cm 3.

Example  5: hydrophobic with water glass Airgel  Produce

To 1 L of 1N hydrochloric acid solution, a water glass solution (a solution of 35% sodium silicate solution diluted three times with water) is added little by little, and the acidity of the solution is adjusted to pH 4. At this time, the temperature of the reactor is 80 ℃, the reaction was stirred for about 2 hours under acidic conditions of pH 3.5 to prepare a wet gel. The wet gel thus prepared is placed in a mixer to remove Na ions present in the gel and washed with distilled water several times for 4 hours. At this time, the amount of Na ions of the washed wet gel was 2000ppm. Washed silica gel uses a silane compound and butanol to simultaneously perform permanent hydrophobic treatment of the surface and water removal in the gel. To this end, the wet gel is immersed in a butanol solution diluted to 5 wt% of ethyl-tri-methoxy-silane (ETES) at an acidic condition of pH 3.5, and then refluxed at 120 to 150 ° C. for 4 hours. The butanol treated wet gel is dried at 150 ° C. for 2 hours to remove butanol present on the gel surface. The thermal conductivity of the powder thus prepared was 9 mW / m · K. The prepared airgel had a particle size of about 0.3 um to 500 mm and a density of about 0.03 to 0.04 g / cm 3.

Example  6: water glass Surface modified  Hydrophobic Airgel  Produce

A surface-modified airgel was prepared in the same manner as in Example 5 except that methoxytrimethylsilane (MTMS) was used as the surface modifier. The hydrophobic surface-modified airgel thus prepared had a thermal conductivity of 11 mW / m · K. The prepared airgel has a particle size of about 0.3 μm-500 mm and a density of about 0.03 to 0.04 g / cm 3.

Example  7: TEOS Using Surface modified  Hydrophobic Airgel  Produce

Tetraethylorthosilicate (TEOS) is mixed with H ₂ O at 1: 6 and adjusted to pH 2 by addition of HCl, an acid catalyst. When mixed at pH 2, TEOS and H ₂ O are hydrolyzed and mixed in a single solution. When the base catalyst NH ₄ OH is added to the hydrolyzed solution and adjusted to pH 8, gelation proceeds and a wet gel can be obtained. The wet gel thus prepared is aged at 50 ° C. for 24 hours, and the wet gel is crushed by a crusher after aging. The granulated wet gel is added to an alcohol solution containing 5% by weight of ethyl trimethoxysilane (ETMS) and refluxed at 150 ° C. for surface hydrophobization. After the reaction, the wet gel is washed with MeOH and dried in a 100bar, 35 ° C supercritical equipment.

Supercritical drying conditions used in this example are as follows. First, the autoclave containing the solvent-substituted sample was purged with carbon dioxide and then heated to 35 to 40 ° C. During heating, the autoclave internal pressure was increased to approximately 1,500 psig. After maintaining this temperature and pressure for 1 to 2 hours, venting with a pressure relief valve while maintaining above the supercritical temperature of carbon dioxide (31 ° C.), the autoclave was operated for 2 to 3 hours at a rate of 15 to 25 psi / min. The pressure was reduced. When the pressure in the autoclave dropped below 100 psig, the autoclave heater was turned off and the remaining alcohol was discharged using nitrogen during cooling.

As a result of drying the prepared wet gel using a supercritical apparatus, an airgel powder having a thermal conductivity of 14 to 15 mW / mK was obtained. The prepared airgel had a particle size of about 0.3 um to 500 mm and a density of about 0.03 to 0.04 g / cm 3.

Example  8: Airgel  Preparation of Sheet Using Particles

12 shows a method for manufacturing an airgel insulating sheet of the present invention.

According to the process shown in FIG. 12, fineness 4d (d is denier of fiber, fiber diameter when making 9,000 m of fiber at 1 g.), Cis-core type polyethylene-polyethylene terephthalate having an average fiber length of 40 mm The composite short fibers were opened and carded and cross-laped to form a web of 100 GSM.

Thereafter, the needle punched nonwoven web was scattered to 40 wt% of the airgel filling amount prepared in Example 1 based on the total weight of the airgel insulation sheet, and then preliminary needle punching was performed at a speed of 200 stroke / min, and 300 After punching the needle at the speed of stroke / min, the surface of the nonwoven fabric was laminated at 180 ° C. for 2 minutes to prepare an airgel insulating sheet. In this embodiment, the process speed of the airgel insulation sheet manufacturing process was 3.5 m / min.

Example  9: Airgel  Preparation of Sheet Using Particles

The filling amount of the airgel particles prepared in Example 5 was used as 50wt%, and after scattering the airgel particles, the needle punching nonwoven web used as the lower layer in Example 8 was again laminated to the airgel particle layer, followed by preneedle punching. Except for the airgel insulation sheet was prepared in the same manner as in Example 8. A micrograph (magnification of 150 times) of the prepared airgel insulating sheet is shown in FIG. 13.

As shown in Figure 13, the airgel heat insulating sheet used in the present invention is aerogel is tightly fixed between the intersected fiber pillars.

Example  10: to the second floor Stacked  Preparation of Airgel Insulation Sheet

An airgel insulating sheet was prepared in the same manner as in Example 8 except that the airgel particles prepared in Example 2 were used. On the other hand, another airgel insulating sheet was prepared by the method of Example 9 except that the airgel prepared in Example 7 was used.

Thereafter, the airgel heat insulating sheet and another airgel heat insulating sheet were laminated and laminated at 100 ° C. for 5 minutes to prepare an airgel heat insulating sheet having two layers of airgel.

Example  11. Preparation of Airgel Insulation Sheet

The airgel prepared in Example 3 and the airgel prepared in Example 4 were mixed and used in a 1: 1 weight ratio, and carbon black having a particle diameter of 1 μm or less was scattered together with the airgel particles at 10 parts by weight per 100 parts by weight of the airgel particles. Except that aerogel insulating sheet was prepared by the method of Example 8.

Example  12. Measurement of insulation properties of airgel insulation sheet

Insulation characteristics of the airgel insulation sheet prepared in Example 8 were measured as follows. After inserting the airgel insulation sheet having a thickness of 3 mm prepared in Example 8 between the lower plate having a heating wire and the upper plate having a temperature sensor, the upper plate was lowered to closely adhere the airgel insulating sheet between the two plates. Prepare a sample cell of a). Then, after heating the temperature of the lower plate to 200 ℃, at this time the temperature of the upper plate was measured to evaluate the heat insulating properties of the airgel heat insulating sheet used in the present invention. On the other hand, for comparison, the needle punch nonwoven fabric used in manufacturing the airgel insulation sheet of Example 8 was placed between the upper and lower plates in the same manner as described above and adhered to each other, and then the temperature of the upper plate was measured and shown in FIG. 14 (b). It was.

As can be seen in Figure 14 (b), the flexible airgel insulating sheet of Example 8 used in the present invention exhibits a significantly lower temperature in the top plate than in the case of the nonwoven sheet, and thus, the flexable used in the present invention. It can be seen that an airgel insulating sheet exhibits excellent insulating properties.

The portable information device according to the present invention has a built-in aerogel insulation sheet configured to reduce heat transfer between the heat generating unit and other parts, thereby preventing damage and malfunction of the parts, and preventing safety accidents that may occur to the user during long-term use. In addition, it is possible to effectively control the heat insulation as a thin thickness heat insulating material in a small internal space.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

Claims (25)

Portable information device, characterized in that the built-in airgel insulation sheet is configured to reduce the heat transfer between the heating portion and the other parts. The method of claim 1, The airgel insulating sheet is portable information device, characterized in that disposed between at least one of the heating unit and the case, between the heating unit and the hard disk drive (HDD), and between the heating unit and the external expansion terminal. The method according to claim 1 or 2, The heating unit is a portable information device, characterized in that selected from the central processing unit (CPU), graphics processing unit (GPU), a printed circuit board (PCB) equipped with the central processing unit and graphics processing unit, a power supply device. . The method according to claim 1 or 2, The portable information device is a portable information device, characterized in that the notebook computer or a mobile phone. The method of claim 1, The airgel insulating sheet, Needle punched nonwovens; And Airgel particles filled in the needle punched nonwoven fabric Portable information device comprising a. The method of claim 5, The needle punching nonwoven fabric is a portable information device, characterized in that the lamination by heat. The method of claim 5, The needle punched nonwoven fabric is a portable information device, characterized in that the composite fiber comprising two or more kinds of polymers having different melting points. The method of claim 7, wherein The composite fiber is a portable information device, characterized in that it comprises at least two polymers selected from the group consisting of polyester, polyamide, and polyolefin. The method of claim 8, The composite fiber is a polyethylene terephthalate (PET) and a portable information device comprising a polyolefin-based polymer having a lower melting point than the PET. The portable information device of claim 5, wherein the airgel particles are filled in the needle punched nonwoven fabric at 10-90 wt%. The portable information device of claim 5, wherein the airgel particles are hydrophobic surface-modified airgels. The method of claim 11, The hydrophobic surface-modified airgel particles of formula R _{1 4-n} -SiX _n or R ₃ Si-O-SiR ₃ Wherein n is 1 to 3, R ₁ is C ₁ -C ₁₀ , preferably C ₁ -C ₅ alkyl or aromatic, heteroaromatic alkyl or hydrogen, X is selected from F, Cl, Br, I A halogen element, preferably Cl or C ₁ -C ₁₀ , preferably C ₁ -C ₅ alkoxy group, or aromatic alkoxy group, heteroaromatic alkoxy group, R ₃ groups are the same or different and C ₁ -C ₁₀ And hydrophobized with a silylating agent of alkyl or aromatic alkyl, heteroaromatic alkyl or hydrogen. The method of claim 12, The silylating agent is hexamethyldisilane, ethyltrimethoxysilane, ethyltriethoxysilane, triethylethoxysilane, trimethylethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methoxytrimethylsilane, trimethyl And at least one member selected from the group consisting of chlorosilanes and triethylchlorosilanes. The method of claim 5, And the airgel particles have a density of 0.01-0.5 g / cm 3. The method of claim 5, Portable needle device, characterized in that the needle punched non-woven fabric additionally filled with an IR opaque (opacifier). The method of claim 15, The IR opaque material is a portable information device, characterized in that at least one selected from the group consisting of carbon black, titanium dioxide, iron oxide and zirconium dioxide. The method of claim 5, The airgel insulating sheet is a portable information device, characterized in that the needle punched nonwoven fabric filled with airgel particles are laminated more than two layers. The method of claim 5, The airgel insulating sheet is a portable information device, characterized in that the thermal conductivity is 40mW / mk or less. The method of claim 5, The airgel insulating sheet is a portable information device characterized in that it further comprises one or more layers of surface protection sheet on one side or both sides. The method of claim 5, The airgel insulating sheet is a portable information device, characterized in that one or both surfaces are water-repellent, coating and / or sealing treatment. The method of claim 1, The airgel insulating sheet, Scattering the airgel particles into the needlepunching nonwoven web; Preneeling the airgel onto the scattered nonwoven web; Needle punching the pre-needle punched web; And Laminating the surface of the needle punched web by heat treatment; Portable information device characterized in that it is manufactured, including. The method of claim 1, The airgel insulating sheet, Scattering the airgel particles into the needlepunching nonwoven web; Laminating a needle punched nonwoven web on the scattered airgel; Preneedle punching the laminate of the needle punched nonwoven web; Needle punching the prepunched web; And Laminating the surface of the punched web by heat treatment; Portable information device characterized in that it is manufactured, including. The method of claim 21 or 22, The preliminary needle punching condition is a portable information device, characterized in that 100 to 300 stroke / min. The method of claim 21 or 22, The needle punching condition is a portable information device, characterized in that 200 to 500 stroke / min. The method of claim 21 or 22, The laminating is a portable information device, characterized in that performed for 1 to 10 minutes at a temperature of 150 to 250 ℃.

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