JPS60174639A - Heat-insulating board - 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 Field of Industrial Application The present invention relates to a heat insulating board used as a heat insulator for refrigerators, freezers, hot storages, frozen prefabricated refrigerators, portable cold storages, and the like.

Structure of the conventional example and its problems The first column shows a conventional heat insulating board. The configuration of this conventional example will be explained below with reference to FIG.

In the figure, 1 is a heat insulating board, and after inserting a foam 2 having open cells, such as a phenolic resin foam, into a bag 32 made of a plastic laminate film or the like, the inside of the bag 3 is heated to 0. After reducing the pressure to about 0.05 Torr, the opening of the bag 3 is sealed by heat sealing.

However, in the above conventional example, the foam 2 is brittle, and the surface of the foam 2 in particular is easily powdered, so when inserting the foam into the bag 3, powder adheres to the opening of the bag 3, causing heat fusion. This may result in incomplete sealing, allowing gas to enter from the heat-sealed area. Furthermore, since the bag 3 itself is not made of a completely gas-impermeable material, gas may sometimes enter the bag due to aging. As a result, the pressure inside the depressurized bag 3 increases, the thermal conductivity of the heat insulating plate 1 increases, and the heat insulating performance of the heat insulating plate deteriorates.

OBJECTS OF THE INVENTION The present invention eliminates the drawbacks of the above-mentioned conventional examples, and aims to prevent the deterioration of the heat insulation performance over time and further improve the heat insulation performance.

Structure of the Invention In order to achieve the above object, the present invention uses a foam having open air bubbles injected and foamed between two shielding plates having metallic luster, and a plastic laminate film or the like for the shielding plate. By inserting the foam into a bag whose main component is plastic, reducing the pressure inside the bag, and sealing the opening of the bag, the surface of the foam does not turn into powder, and the powder adheres to the opening of the bag, resulting in thermal fusion. This is to prevent defects.

Furthermore, the gas impermeability of the bag is apparently improved, gas infiltration is reduced, and the deterioration of the heat insulating performance over time is reduced.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. Note that the same configurations as those of the prior art are given the same numbers and detailed explanation thereof will be omitted.

In the figure, 4 is a heat insulating board, 5 is an aluminum foil shielding board, and 6 is a phenol resin foam. 250m
m, cut out into a square with a width of 250 mm and housed in a bag 3 made of plastic laminate film, etc. After reducing the pressure inside the bag 3 to 0.05 Torr, the opening is sealed by heat fusion to form a heat insulating board 4. are doing.

In producing the heat insulating board 4, most of the surface of the foam 6 is covered with the shielding plate 6, so that the surface of the foam 6 is not powdered when the foam 6 is placed in the bag 3. Therefore, the powder does not adhere to the opening of the bag 3 and the heat sealing is completed, so that gas does not enter from the heat sealing part. In addition, since the shielding plate 5 is in close contact with the bag 3, the gas impermeability of the bag 3 is apparently improved, and the amount of gas intruding into the inside of the bag 3 is reduced.
This has the advantage that the pressure increase inside the bag 3 is suppressed, and the deterioration of the heat insulation performance of the heat insulation board 4 over time is reduced.

In addition, the shielding plate 5 also blocks radiant heat due to the mirror effect caused by the metallic luster and prevents heat transfer by radiation, so the heat insulating plate 5
It has the advantage of reducing thermal conductivity and providing excellent heat insulation performance.

Furthermore, since the shielding plate 6 has a metallic luster and has low frictional resistance on the surface, the foam 6 is injected between the two shielding plates 5 and then spreads between the shielding plates 5 while foaming. Since the surface becomes smooth, bubbles are generated uniformly, and the bubble diameter becomes smaller. As the diameter of the bubbles 6' becomes minute, heat transfer by convection of the gas 9 in the foam 6 is hindered, the thermal conductivity of the heat insulating plate 4 decreases, and there is an advantage that excellent heat insulating performance can be obtained. . Furthermore, since the bubble diameter becomes minute, the effect of reducing thermal conductivity due to pressure reduction can be obtained from a relatively low vacuum, so there is an advantage that the time required for pressure reduction is shortened and production efficiency is improved.

In this embodiment, aluminum foil was used for the shielding plate 6, but metals such as copper, iron, and stainless steel, or plastics to which metallic luster was added using means such as vapor deposition, sputtering, and plating, may also be used. It is possible. In addition, the foam 6
Although phenol resin was used, other resins such as urethane resin can be used without any limitation as long as they can be injected and foamed between the two shielding plates 5.

Effects of the Invention As described above, the present invention includes a foam having open cells injected between two shielding plates having a metallic luster, and inserting the shielding plate into a bag mainly made of plastic, and then inserting the shielding plate into a bag mainly made of plastic. By sealing the opening of the bag after reducing the pressure, the following effects can be obtained.

(a) Since most of the surface of the foam is covered with a shielding plate, the surface of the foam does not powder when the foam is placed in a bag, and powder does not adhere to the opening of the bag. The bag opening is completely heat-sealed, and gas does not enter through the heat-sealed portion.

(b) In addition, since the shielding plate is in close contact with the bag, the gas impermeability of the bag is apparently improved, and the amount of gas intruding into the inside of the bag is reduced, so the increase in pressure inside the bag is suppressed. The aging deterioration of the heat insulating performance of the heat insulating board is reduced, and the heat insulating board can maintain excellent heat insulating performance over a long period of time.

(0) The shielding plate blocks radiant heat due to its mirror effect due to metallic luster and prevents heat transfer by radiation, thereby reducing the thermal conductivity of the heat insulating plate, making it possible to obtain a heat insulating plate with extremely excellent heat insulation performance.

(d) Since the frictional resistance of the surface of the shielding plate is small, when the foam is injected between the two shielding plates and spreads between the shielding plates while foaming, the flow becomes smooth and the air bubbles become The bubbles are generated uniformly and the bubble diameter is miniaturized.

(e) As the cell diameter becomes minute, heat transfer due to gas convection within the foam is hindered and the thermal conductivity of the insulation board decreases, making it difficult to obtain a insulation board with extremely excellent insulation performance. can.

(f) Furthermore, because the bubble diameter becomes minute, the effect of reducing thermal conductivity due to reduced pressure can be obtained at a relatively low vacuum.
This has the advantage of shortening the time required for depressurization and improving production efficiency.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional heat insulating board, Fig. 2 is a sectional view of a heat insulating board according to an embodiment of the present invention, and Fig. 3 is a perspective view of a foam injected and foamed between the shielding boards in Fig. 2. be. 6... Shielding plate, 6... Foam, 3...
...Bag, 4...Insulation board. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Δ

Claims (1)

[Claims] Two shielding plates with metallic luster, a foam having open cells injected and foamed between the two shielding plates, and a bag mainly made of plastic that houses the shielding plates and the foam and reduces pressure. A heat insulating board made of.