JPS61241593A - Heat-insulating panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 111 Industrial application fields The present invention relates to a heat insulating panel.

(2) Conventional examples and their problems Conventionally, inorganic materials such as glass fiber and perlite, and organic materials such as foamed polyurethane and foamed borostyrene have been known as materials having a heat insulating effect.

As a low-temperature insulation material, hard polyurethane foam is generally used, and it alone has 0.015 kcal/inh'
Although a thermal conductivity of C has been achieved, it is difficult to further improve the thermal insulation performance. Also, as a cold insulating material for cryogenic temperatures such as liquefied nitrogen containers and refrigerators, a powder vacuum insulation method is known in which foamed perlite or the like is filled into the gap of a double-walled container and evacuated to a high vacuum. 1
In order to obtain a thermal conductivity of 5 kcal/mh'C or less, it is necessary to evacuate to a high vacuum with an internal pressure of f70.01 torr or less. Applying such a high vacuum to a container has technical and economical problems that require ultra-high performance vacuum pumps and special equipment that is completely leak-proof.

(3) Purpose of the Invention The present invention addresses the above-mentioned problems, namely, in a heat insulating panel formed by evacuating the inside of a container filled with a heat insulating material, the vacuum is evacuated to a level as high as in the past. The purpose is to provide a heat insulating panel with good heat insulating performance.

(4) Structure of the Invention The present invention provides a heat insulating panel formed by filling a sealable container with a heat insulating material and evacuating the container to vacuum. This is an insulating panel featuring the following.

(51 Effects □ According to the present invention, by replacing the air with a gas that has a lower thermal conductivity than air, a high-performance product with a lower thermal conductivity can be achieved without having to evacuate to a higher vacuum than when no gas replacement is performed.) A heat insulating panel is obtained.

(6) Description of examples The present invention will be explained below with reference to the drawings.

FIG. 1 is a sectional view of the basic structure of an embodiment of the heat insulating panel of the present invention. A heat insulating material 2 is filled in a container 1,
``The inside of the container 1 is evacuated after being replaced with a gas having low thermal conductivity, and the container 1 is sealed.

Container 1 may be a metal container made of iron, copper, stainless steel, aluminum, etc., phenol resin, poly-11 ester resin, vinyl chloride resin, poly-11 styrene, poly-11 ethylene, poly-11
Plastic containers such as propylene poly-11amide can be used, but from a practical standpoint, considering the fact that they can be easily vacuum-sealed and the high-performance heat insulation properties, it is preferable to use a plastic container with a heat-adhesive layer. Plastic laminated film containers are preferred.

The heat insulating material 2 is a powder of calcium silicate, 711, magnesium carbonate, perlite, etc., a hollow spherical shell powder such as silica microballoon, foamed perlite, or inorganic fiber such as glass wool or ceramic wool. When filling the heat insulating material 2, use it after thoroughly drying it.

An example of a gas with low thermal conductivity used for substitution is chlorofluorocarbon gas, and fluorocarbon=12 (dichlorodifluoromethane, chemical formula: Cc12F2) is effective. The thermal conductivity of Freon-12 is 0.010 kcal/m
h'C, and the thermal conductivity of air is o, o 19kca
Since it is fmh'C, it is effective in blocking the heat transfer of residual gas.

Next, the present invention will be explained in more detail using specific examples.

In this implementation, the thermal conductivity was measured using Showa Denko's R,T'M thermal conductivity measuring device, according to ASTM-
Thermal conductivity at a temperature difference of 15°C and 55°C was measured by a method based on C518.

<Example> Expanded pearlite pulverized powder (average particle size 6-μm) was
Fill it into an ester non-woven bag and it'? After vacuum drying at 150° C., the mixture was brought to room temperature in an atmosphere of 100% Freon-12 and stored for 24 hours, and the spaces between the crushed expanded pearlite powders were replaced with Freon-12. The inner layer is made of polyethylene (60 μm thick), the middle layer is aluminum (9 μm thick), and the surface layer is boroethylene tereflate (12 μm thick). 0.5 torrQ
(m, vertical width 25Crrt insulation panel was obtained.Thermal conductivity of the obtained insulation panel was o, oO7kcal/mh
It was o.

Comparative Example> On the other hand, the thermal conductivity of a heat insulating panel obtained in the same manner as in the example without replacing with Freon-12 gas was o, 012
kcal/mh'C, and similarly Freon-12
Thermal conductivity of a heat insulating panel obtained in the same manner as in the example without replacing with gas and evacuating the inside of the laminate film container to a vacuum level of 0.01 torr was 0, OO7.
It was kcal/mh'C.

(71 Effects of the Invention As described above, the present invention is characterized in that, in a heat insulating panel formed by filling a sealable container with a heat insulating material and evacuating the container, the interior of the container is replaced with flocci gas before being evacuated to a vacuum. By using fluorocarbon gas, a gas with lower thermal conductivity than air, high-performance insulation panels with low thermal conductivity can be obtained without having to be evacuated to a high vacuum. Extremely large.

[Brief explanation of drawings]

The drawing is a sectional view showing the basic structure of the heat insulating panel of the present invention.

Claims (1)

[Claims] 1) A heat insulating panel characterized by filling a sealable container with a heat insulating material, replacing the inside of the container with a gas having low thermal conductivity, and then evacuating the container to a vacuum. 2) The heat insulating panel according to claim 1, wherein the gas having low thermal conductivity is dichlorodifluoromethane.