JP4251463B2 - Thermal insulation sheet and thermal insulation - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat insulating sheet and insulation using heat-reflecting and vacuum insulation.
[0002]
[Prior art]
Conventionally, the structure which laminated | stacked the heat ray reflective sheet through the air layer is well-known as a heat insulating body (Unexamined-Japanese-Patent No. 5-26391). This heat insulator has an action of reflecting the heat rays radiated from the heat source with the heat ray reflecting sheet, while insulating the heat from the heat source with the air layer.
[0003]
One method for improving the heat insulation performance of such a heat insulator is to improve the heat insulation performance of the air layer portion. For example, the structure which improves heat insulation can be considered by attaching highly heat-insulating hollow vacuum particles whose inside is reduced in vacuum to the surface of the heat ray reflective sheet and replacing a part of the air layer with vacuum hollow particles.
[0004]
[Problems to be solved by the invention]
However, when the hollow vacuum particles are attached to the surface of the heat ray reflective sheet, the hollow vacuum particles are less likely to adhere uniformly, and the ratio of the hollow vacuum particles covering the surface of the heat ray reflective sheet is reduced. There was a problem that the effect of was difficult to increase.
[0005]
The present invention, in consideration of such problems of the conventional thermal insulator, and to provide a more excellent heat insulating properties and heat insulating sheet and the heat insulating member as compared with the prior art.
[0006]
[Means for Solving the Problems]
The first aspect of the present invention is a heat ray reflective sheet;
A mesh-like sheet formed on the heat ray reflective sheet;
Hollow vacuum particles disposed in voids in the mesh sheet surface;
A thermal insulation sheet having
The hollow vacuum particles are heat insulating sheets having a particle size larger than the thickness of the mesh sheet.
The second of the present invention, the hollow vacuum particles are heat insulation sheet of the first aspect of the present invention in contact said hollow vacuum particles adjacent to each other.
The third aspect of the present invention is the heat insulating sheet according to the first or second aspect of the present invention, wherein the mesh sheet is a woven fabric composed of weft lines and warp lines.
The fourth aspect of the present invention is the heat insulating sheet according to any one of the first to third aspects of the present invention, wherein the surface of the mesh sheet is made of a heat-sealing adhesive resin.
The fifth aspect of the present invention is the heat insulating sheet according to any one of the first to third aspects, wherein an adhesive layer is formed on the surface of the heat ray reflective sheet.
According to a sixth aspect of the present invention, the material for the adhesive layer is any one of a photocurable resin, a radiation curable resin, and a thermosetting resin. It is a heat insulation sheet.
The seventh aspect of the present invention is a heat insulating body comprising one or a plurality of the heat insulating sheets of the first to sixth aspects of the present invention.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
The conceptual diagram of the heat insulation sheet which comprises the heat insulating body which is one embodiment of this invention is shown in FIG. That is, as shown in the figure, in the heat insulating sheet 1 of the present embodiment, the mesh sheet 3 is laminated on the heat ray reflective sheet 2, and the vacuum hollow particles 4 are formed in the voids in the surface of the mesh sheet 3. Is arranged.
[0011]
Since the mesh sheet 3 is laminated on the heat ray reflective sheet 2 and the void portions are regularly arranged in the surface of the mesh sheet 3, the hollow vacuum particles 3 are placed in the void portions when the hollow vacuum particles 4 are arranged. Since the position of the hollow vacuum particles 4 is easily fixed by fitting in at least a part of the gaps, the hollow vacuum particles 4 are densely arranged on the surface of the heat ray reflective sheet 2 corresponding to the gaps. Is done.
[0012]
Although the heat insulation body of this invention can also comprise a heat insulation sheet only by 1 layer, in the case of the structure which laminated | stacked the heat insulation sheet, still higher heat insulation is acquired. A heat insulating body in which the heat insulating sheet 1 is multilayered can be configured by stacking the cut heat insulating sheets 1. In addition, since the heat insulating sheet 1 in the present invention has flexibility, for example, the heat insulating sheet 1 is wound around the heat source 5 in multiple layers as shown in FIG. Thus, it is possible to easily form a multilayer structure by providing a heat insulating body formed by bending a plurality of heat insulating sheets 1 on the surface of the heat source 5. 2 and 3 are schematic side views of the heat insulator.
[0013]
Since the heat insulator of the present invention has heat ray reflectivity, it is effective for heat insulation to be disposed adjacent to the heat source. Moreover, the heat insulation effect can be further improved by arranging another heat insulator such as plastic foam or glass wool on the side opposite to the heat source with respect to the heat insulator of the present invention.
[0014]
The heat ray reflective sheet of the present invention needs to be able to reflect and insulate at least infrared rays having a wavelength of about 2 μm or more, which becomes radiant heat from a heat source. Examples of the heat ray reflective sheet include a metal foil such as aluminum or copper, a sheet deposited with semiconductor or metal, or a sheet coated with semiconductor or metal fine particles. If the heat ray reflective layer has a thickness of about several hundred nm, a sufficient heat ray reflection effect can be obtained. Since the heat ray reflective layer has good heat conductivity, if the film thickness is large, the heat conduction in the heat ray reflective layer part will deteriorate the heat insulation performance of the heat insulator, and therefore attention should be paid.
[0015]
The mesh-like sheet of the present invention needs to have finely divided void portions regularly and densely in the sheet surface in order to arrange the hollow vacuum particles at a high density. The specific size of the void portion is preferably in the range of several μm to several mm when expressed by the square root of the void portion area. Moreover, in order to suppress the deterioration of the heat insulation performance due to heat conduction in the mesh sheet as much as possible, the hole of the void portion penetrates the sheet, and the total area of the void portion with respect to the area of the entire sheet is increased. is necessary. Similarly, the thickness of the sheet needs to be as small as possible from the viewpoint of suppressing a decrease in heat insulation performance due to heat conduction in the sheet.
[0016]
There is no particular limitation on the form of the mesh-like sheet, but when a woven fabric composed of weft and warp wires is used as the mesh-like sheet, it has flexibility and easily achieves the necessary conditions for the mesh-like sheet. can do. It is also possible to form a mesh sheet by printing the mesh sheet directly on the surface of the heat ray reflective sheet.
[0017]
The material of the mesh sheet is not particularly limited as long as it is a flexible material, and plastic or metal is used. In order to suppress a decrease in heat insulation due to absorption of heat rays in the mesh sheet, the surface of the mesh sheet preferably has heat ray reflectivity. Examples of a method for imparting heat ray reflectivity include a method in which the mesh sheet is made of a heat ray reflective material, or a surface treatment is performed with a heat ray reflective material by vapor deposition or coating. In particular, when the mesh-like sheet is a woven fabric, it can be easily configured using a metal fine wire such as a stainless fine wire, a copper fine wire, or an aluminum fine wire. It is also possible to form a thin film of metal such as aluminum, copper, silver or gold on the surface of the thin plastic wire.
[0018]
The hollow vacuum particles of the present invention need to be able to effectively insulate compared with air by being in a hollow vacuum state. In general, the heat insulation performance of the gas in the hollow portion is determined by the degree of vacuum in the hollow vacuum particles and the hollow diameter. That is, the heat insulation performance is determined by the mean free path of the gas remaining in the hollow vacuum particles at a certain degree of vacuum and the hollow diameter. As the degree of vacuum is increased as much as possible and the hollow diameter is decreased, a heat insulating effect can be obtained. For example, if the degree of vacuum is about 10 ⁻¹ torr, a remarkable heat insulation effect can be obtained by reducing the hollow diameter to about 500 μm. If the degree of vacuum is about 10 ⁻² torr, the hollow diameter can be reduced to about 5 mm. A remarkable thermal insulation effect is obtained.
[0019]
In general, the hollow vacuum particles preferably have a particle size larger than the thickness of the mesh sheet as shown in FIG. When the heat insulating body of the present invention is laminated, if the thickness of the mesh sheet is larger than the particle diameter, the heat ray reflective sheet and the mesh sheet are in line contact between the layers of the heat insulating body. When the diameter is larger, the heat ray reflective sheet and the hollow vacuum particles are in point contact and the heat insulation effect is improved. However, when a woven fabric is used as the mesh-like sheet, the thickness of the mesh-like sheet increases at the point where the weft lines and the warp lines intersect. For this reason, the mesh-like sheet and the heat ray reflective sheet are in contact with each other at a crossing point in a state close to point contact, so that there is no particular restriction on the particle size of the hollow vacuum particles.
[0020]
In the hollow vacuum particles of the present invention, the wall material of the particles is preferably made of a gas barrier material in order to maintain the vacuum state inside the particles. As the material, glass, ethylene vinyl alcohol copolymer, acrylonitrile-butadiene-styrene copolymer, polyvinylidene chloride, and the like can be used.
[0021]
The heat insulating sheet in the heat insulating body of the present invention requires that the heat ray reflective sheet, the mesh sheet, and the hollow vacuum particles are bonded and integrated. The bonding method is not particularly limited, but there are the following two types as relatively efficient manufacturing methods.
[0022]
(1) A type in which the surface of the mesh sheet is made of an adhesive resin, and the heat ray reflective sheet and the hollow vacuum particles are bonded and integrated via the adhesive resin (hereinafter referred to as a first type).
[0023]
(2) A type in which the heat ray reflective sheet and the mesh sheet, and the heat ray reflective sheet and the hollow vacuum particles are bonded and integrated by an adhesive layer formed on the surface of the heat ray reflective sheet (hereinafter referred to as a second type). ).
[0024]
Hereinafter, regarding the first and second types, the configuration of the heat insulator is described with reference to the drawings, and an embodiment of the manufacturing method thereof is also described.
[0025]
That is, FIG. 5 shows the state of adhesion in the first type.
[0026]
As shown in the figure, the heat ray reflective sheet 2 and the hollow vacuum particles 4 are bonded and integrated through a mesh sheet 53 whose surface is made of an adhesive resin. In this case, since the bonding is performed on the surface of the mesh sheet 53, the size of the gap of the mesh sheet 53 or the particle size of the hollow vacuum particles 4 is set so that the mesh sheet 53 and the hollow vacuum particles 4 are particularly in contact with each other. Need to optimize.
[0027]
As a specific manufacturing method in this case, after the mesh-like sheet 53 whose surface is made of a heat-sealing adhesive resin is overlaid on the heat ray reflective sheet 2, the hollow vacuum particles 4 are placed in the voids of the mesh-like sheet. After the arrangement, the method of performing the process of heating and fusing the heat-fusing adhesive resin is preferable because adhesion and integration can be realized in a dry manner. The mesh sheet 53 includes a method of forming the mesh sheet with a heat-fusible adhesive resin in addition to the method of coating the surface of the mesh sheet with a heat-sealing adhesive resin by post-processing. In particular, when the mesh sheet is a woven fabric, a thin line made of a heat-fusible resin can be used for the weft line or the warp line. Examples of the heat-fusible resin include polyethylene, linear low density polyethylene, and polypropylene.
[0028]
Next, FIG. 6 shows the state of adhesion in the second type described above.
[0029]
As shown in the figure, the mesh sheet 3 and the hollow vacuum particles 4 are bonded and integrated by the adhesive layer 6 formed on the heat ray reflective sheet 2.
[0030]
A specific manufacturing method in this case will be described with reference to FIG. After forming the adhesive layer 6 on the surface of the heat ray reflective sheet 2 (corresponding to the step marked with A in the figure), the mesh layer 3 and the heat ray are left in the adhesive layer 6 in an uncured state, leaving adhesiveness. After the reflecting sheet 2 was bonded to the reflective sheet 2 via the adhesive layer 6 (corresponding to the step marked B in the figure), the hollow vacuum particles 4 were adhered to the voids of the mesh sheet 3 (the figure). The method of performing the step of curing the adhesive layer 6 by the exposure apparatus 7 (indicated by D in the figure) after the step C) is relatively simple and preferable. In particular, in order to perform adhesion and integration while leaving the adhesive layer 6 with the adhesiveness left, the positions of the mesh sheet 3 and the hollow vacuum particles 4 are temporarily fixed on the heat ray reflective sheet 2 and are easy to handle. Further, if necessary, a pressure roll is provided between the step C and the step D, and the temporarily fixed mesh-like sheet 3 and the hollow vacuum particles 4 are pressure-bonded to the heat ray reflective sheet 2 so as to adhere. Is performed more reliably.
[0031]
Although a general adhesive material can be used for the adhesive layer 6, an adhesive selected from a photocurable resin, a radiation curable resin, and a thermosetting resin is particularly preferable in terms of handling. Examples of the photocurable resin include an ultraviolet curable resin and an infrared curable resin. Examples of radiation curable resins include X-ray curable resins and electron beam curable resins. In order to minimize the absorption of heat rays from the heat source in the adhesive layer 6, the thickness of the adhesive layer 6 is preferably as thin as possible so that the mesh-like sheet 3 and the hollow vacuum particles 4 can be bonded, and is preferably about several μm.
[0032]
Next, since the heat insulation sheet of the said 1st and 2nd type was manufactured and the heat insulation performance was confirmed, the specific example is further demonstrated.
[0033]
(Specific example 1)
Here, the first type heat insulating sheet will be described.
[0034]
As the heat ray reflective sheet, a sheet laminated with polyethylene terephthalate (12 μm), polyethylene (13 μm), aluminum foil (9 μm), and polyethylene (40 μm) was used.
[0035]
As the mesh sheet, a woven fabric in which the weft and warp wires were composed of polyethylene thin wires (diameter of 50 μm), which is a heat-sealable adhesive resin (void portion: 300 μm × 300 μm), was used.
[0036]
As the hollow vacuum particles, those made of glass having an average hollow diameter of 500 μm and a degree of vacuum of about 0.01 torr were used.
[0037]
After stacking the mesh sheet on the polyethylene layer side of the heat ray reflective sheet, after placing the hollow vacuum particles in the gap of the mesh sheet, the entire sheet is crimped and integrated while heating to about 100 ° C to form a heat insulating sheet did.
[0038]
When the surface of the heat insulating sheet was observed with a microscope, it was confirmed that almost 100% hollow vacuum particles were arranged in the void portion of the mesh sheet.
[0039]
(Comparative Example 1)
In Specific Example 1, without arranging a mesh-like sheet, after arranging hollow vacuum particles on the surface of the polyethylene layer of the heat ray reflective sheet, the whole sheet was pressure-bonded and integrated while heating to about 100 ° C., and heat insulation as Comparative Example 1 A sheet was constructed.
[0040]
When the surface of this heat insulating sheet was observed with a microscope, a part of the arranged hollow vacuum particles fell from the surface of the polyethylene layer, so that the number of particles per unit area in the heat ray reflective sheet was about 50% with respect to Example 1. Reduced.
[0041]
When the heat insulation sheet created in Specific Example 1 and Comparative Example 1 was wound 10 times around a cylindrical heat source (80 ° C.) and a heat insulator was formed around each heat source, the heat insulation sheet created in Comparative Example 1 was used. Compared with the case where it was, the heat insulation performance was improved about 20% by using the heat insulation sheet created in the specific example 1.
[0042]
(Specific example 2)
Here, the second type heat insulating sheet will be described.
[0043]
As a heat ray reflective sheet, aluminum was vapor-deposited with a thickness of 0.5 μm on polyethylene terephthalate (12 μm).
[0044]
As the mesh sheet, a woven fabric in which weft and warp wires were made of stainless steel wires (30 μm diameter) was used (void portion: 300 μm × 300 μm).
[0045]
The same hollow vacuum particles as those in Example 1 were used.
[0046]
After forming an adhesive layer (3 μm) made of UV curable resin on the polyethylene terephthalate side of the heat ray reflective sheet, the mesh layer and the heat ray reflective sheet are pasted with the adhesive layer while leaving the adhesive layer uncured. After being combined, the hollow vacuum particles are adhered to the voids of the mesh-like sheet, and then the sheet surface is pressure-bonded with a pressure roll, and then the adhesive layer is cured by irradiating the sheet surface with ultraviolet rays. Configured.
[0047]
When the surface of the heat insulating sheet was observed with a microscope, it was confirmed that almost 100% hollow vacuum particles were arranged in the void portion of the mesh sheet.
[0048]
(Comparative Example 2)
In Specific Example 2, without using a mesh-like sheet, hollow vacuum particles are arranged on the surface of the heat-curing reflective sheet in an uncured state, and then the sheet surface is pressure-bonded with a pressure roll, and then ultraviolet rays are applied to the sheet surface. By irradiating, the adhesive layer was hardened, and the heat insulation sheet as the comparative example 2 was comprised.
[0049]
When the surface of the heat insulating sheet was observed with a microscope, the hollow vacuum particles were unevenly arranged, and the number of particles per unit area in the heat ray reflective sheet was reduced to about 70% with respect to the specific example 2.
[0050]
Folding the heat-insulating sheets created in Specific Example 2 and Comparative Example 2 respectively constituted heat-insulating bodies laminated in 10 layers. When these heat insulators are stacked on a heat source composed of a planar heating element (50 ° C.), heat insulation is achieved by using the heat insulation sheet created in specific example 2 as compared to the case where the heat insulation sheet created in comparative example 2 is used. The performance was improved by about 5%.
[0051]
As described above, a heat insulating sheet characterized by having a heat insulating sheet in which a mesh sheet is laminated on a heat ray reflective sheet and a plurality of hollow vacuum particles are arranged in a gap portion in the mesh sheet surface. By the operation, the hollow vacuum particles can be densely arranged on the surface of the heat ray reflective sheet, the coverage on the heat ray reflective sheet by the hollow vacuum particles can be improved, and excellent heat insulation performance can be obtained.
[0052]
【The invention's effect】
As apparent from the above description, the present invention has an advantage that it is more excellent in heat insulation.
[Brief description of the drawings]
FIG. 1 is a perspective view of a heat insulating sheet according to an embodiment of the heat insulator of the present invention. FIG. 2 is an explanatory view showing an embodiment of the heat insulator of the present invention. FIG. 4 is a perspective view of a heat insulating sheet showing an embodiment of the heat insulator of the present invention. FIG. 5 is a schematic cross-sectional view showing an embodiment of the heat insulator of the present invention. FIG. 7 is a schematic cross-sectional view showing an embodiment of a heat insulator of the present invention. FIG. 7 is a schematic process diagram showing an embodiment of a method of manufacturing the heat insulator of the present invention.
DESCRIPTION OF SYMBOLS 1 Heat insulator 2 Heat ray reflective sheet 3 Mesh-like sheet 4 Hollow vacuum particle 5 Heat source 6 Adhesive layer 7 Exposure apparatus

Claims (7)

A heat ray reflective sheet ;
A mesh-like sheet formed before Symbol heat reflecting sheet,
A hollow vacuum particles disposed in the gap portion of the front Symbol mesh sheet plane,
A thermal insulation sheet having,
The heat insulating sheet, wherein a particle diameter of the hollow vacuum particles is larger than a thickness of the mesh sheet . Before SL hollow vacuum particles, insulation sheet according to claim 1, characterized in that in contact said hollow vacuum particles adjacent to each other. The heat insulating sheet according to claim 1 or 2, wherein the mesh sheet is a woven fabric composed of weft lines and warp lines. The heat insulating sheet according to any one of claims 1 to 3, wherein a surface of the mesh sheet is made of a heat-fusing adhesive resin . The heat insulating sheet according to any one of claims 1 to 3, wherein an adhesive layer is formed on a surface of the heat ray reflective sheet. The heat insulating sheet according to claim 5, wherein the material of the adhesive layer is any one of a photocurable resin, a radiation curable resin, and a thermosetting resin. A heat insulator comprising one or more layers of the heat insulating sheet according to any one of claims 1 to 6.

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