JPH08233193A - Heat insulating panel - Google Patents

Abstract

PURPOSE: To obtain a panel having superior adiabatic performance by constituting an adiabatic panel formed by thermally fusing a pair of laminated films at their insides, and using an outer wrapping body, an outer shape retaining material, and a plastic film as each inner layer side, and a metal film as each outside layer by using a metal film having thermal conductivity lower than that of aluminum. CONSTITUTION: An outer wrapping body 4 consists of a pair of top and bottom laminated films 8, 10. The inside peripheral edges of plastic films, 8a, 10a, innermost layers, are abutted to each other and are thermally fused to reduce internal pressure to a vacuum state. A material for constituting outer wrapping metal films 8b, 10b uses lead, tin, lead-based or tin-based alloy, preferably, chromium nickel steel, nickel chromium alloy, etc., having thermal conductivity lower than that of aluminum. Unlike the use of aluminum, interrupting movement of heat on the surface of the outer wrapping body 4 requires no removal of the metal located on the peripheral edge parts, 12, 14, sloped parts 16, 18. Thus, adiabatic performance is dramatically enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an outer envelope whose inside is substantially depressurized to a vacuum state in order to insulate heat from the outside for keeping heat or cold, and the outer envelope is low. The present invention relates to a heat insulation panel having a structure in which an outer shape maintaining member is inserted inside the outer envelope body in order to prevent the outer envelope body from being deformed by internal pressure and maintain its outer shape.

[0002]

2. Description of the Related Art Conventionally, glass fibers and urethane foam have been used as heat insulating materials for keeping warm and cold. While glass fiber has excellent heat resistance, it has a low heat insulating effect in terms of high thermal conductivity. Some urethane foams have low thermal conductivity and have a heat insulating effect, but there is a limit to improvement of heat insulating properties. When the expanded perlite powder is vacuum-sealed in a plastic container, the movement of heat on the plastic surface is reduced, but the degree of vacuum is reduced quickly. On the other hand, when a foil such as aluminum is put in, the degree of vacuum is less deteriorated (deteriorated), but the heat is transferred through the metal part to lower the heat insulating property. Then, as one of the prior arts for solving this, there is a heat insulating panel as described in, for example, Japanese Patent Laid-Open No. 61-144492.

In the following, referring to FIG. 5, not only the technique described in this publication, the inside is evacuated in order to secure a low thermal conductivity, and therefore a gas barrier (gas impermeable) film is used. A conventional heat insulation panel will be described.
Although this heat insulating panel is used for a refrigerator, its planar shape is not shown in the figure, but it is suitable for the shape of a refrigerator door or outer wall. The heat insulation panel whose cross section is shown in FIG. 5 includes an outer envelope body 4 and an outer shape maintaining member 6 for maintaining the outer shape of the outer envelope body 4. The outer envelope body 4 has a predetermined outer shape suitable for being used as a heat insulation panel of the refrigerator, and its internal pressure is reduced to a vacuum state so as to obtain a predetermined heat insulation state. This outer casing 4 is also made of a plastic film 8 which can be heat-welded.
a, 10a on the innermost layer side, aluminum foil (film) 8b, 10b as a metal film on the intermediate layer side, and plastic films 8c, 10c for protection on the outermost layer side, a three-layer laminated film 8, A pair of upper and lower layers 10 and the innermost plastic film 8a, 10a
After abutting the peripheral edges (portions 12 and 14 in the figure) of the inner surface of the above, heat-welding a required portion on the peripheral edge, and vacuuming the unheated welded portion to reduce the internal pressure to a vacuum state,
The non-heat-welded portion is heat-welded and sealed.

The outer shape maintaining member 6 is inserted inside the outer envelope body 4 before heat-sealing the outer envelope body 4 and is a constituent material for maintaining the outer shape of the outer envelope body 4 against the internal pressure. It is composed of fine powder 6a for fulfilling the function, and an appropriate breathable paper 6b for containing fine powder 6a and preventing scattering of fine powder 6a during the depressurization process in outer casing 4.

[0005]

In the conventional heat insulating panel, since it is necessary to maintain the internal pressure in a high vacuum state in order to obtain the heat insulating state, the permeation of gas into the inside which hinders the maintenance is suppressed. Therefore, an aluminum film is used in addition to the plastic film. Aluminum is a metal and is extremely effective in suppressing gas permeation, but aluminum is made thicker in order to sufficiently suppress gas permeation in order to maintain thermal insulation performance for a long period of time.

However, aluminum has a very large thermal conductivity of 175 kcal / m · hr · ° C., and as the wall thickness increases, the heat transferred to the surface of the panel through aluminum increases, and the heat insulation performance is increased. However, there was a problem in that

As a measure for solving the problem due to the heat transfer, the peripheral portion 1 of the outer envelope body 4 which protrudes horizontally in the figure.
It is necessary to remove the aluminum located in the parts 2 and 14 and the slanted parts 16 and 18, so that the gas easily permeates from the part where the aluminum is removed, and the outer casing 4
This causes a decrease in the internal pressure of the product, resulting in a marked decrease in its heat insulating performance. In this way, when the heat insulating panel is used as a heat insulating panel for a refrigerator, for example, improvement of the heat insulating performance is desired.

In the present invention, the use of a metal different from aluminum eliminates the need to remove the metal at the peripheral portion of the outer envelope, effectively suppressing gas permeation into the interior of the outer envelope as a whole, and thus achieving a vacuum degree. The purpose of the invention is to provide a heat-insulating panel that can maintain high heat insulation performance.

[0009]

In order to achieve such an object, in the heat insulation panel of the present invention, an outer package having a predetermined outer shape and the inside of which is decompressed to a predetermined heat insulating state, and the outer package. An outer shape maintaining member that is inserted into the body to maintain the outer shape of the outer envelope body against the reduced pressure, wherein the outer envelope body has a heat-weldable plastic film on the inner layer side and a metal film on the outer layer side. Which is composed of a pair of laminated films of at least two layers, and the inner peripheral edges of the respective plastic films are heat-welded to each other in a state where the inner layer sides of the laminated films are opposed to each other, and the metal film is made of aluminum rather than aluminum. It is characterized by being made of a metal material having a low thermal conductivity.

The outer shape maintaining member preferably contains an inorganic fine powder as a reinforcing material, and a breathable material for containing the fine powder to prevent the inorganic fine powder from scattering during a pressure reduction process inside the outer package. Composed of things.

The outer shape maintaining member is preferably composed of an open cell organic foam.

The metal material constituting the metal film having a lower thermal conductivity than aluminum is preferably lead, a lead-based alloy, tin, a tin-based alloy, an alloy containing lead and tin, or in terms of thermal conductivity. Composed of similar metals.

[0013]

When aluminum is conventionally used as the metal for preventing gas permeation in the outer package, heat is transferred to the surface of the outer package through the aluminum because of its high thermal conductivity. Since the heat insulation performance is easily deteriorated, aluminum was removed from the outer edge of the outer package in order to block the transfer heat.Therefore, internal pressure rise due to gas permeation from the aluminum removed part. It was unavoidable that the heat insulation performance deteriorated.

In the present invention, since a film made of a metal having a smaller thermal conductivity than aluminum is used, not only the heat insulation performance is superior to the case where aluminum is used, but also an outer envelope such as aluminum is used. Since the moving heat is greatly reduced, it is no longer necessary to remove the metal on the peripheral edge of the outer package to shut off the heat,
As a result, the outer package has no portion through which gas easily permeates, and the heat insulation performance is further improved by that much.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view of a heat insulating panel according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. With reference to these drawings, the heat insulation panel 2 of the first embodiment
Is used for, for example, a refrigerator door or an outer wall, and as a basic configuration, the outer envelope body 4 whose internal pressure is reduced to a vacuum state so as to be in a predetermined heat insulating state, and the outer shape of the outer envelope body is set to the inner pressure. External shape maintaining member 6 for resisting and maintaining
It consists of

The outer envelope body 4 is composed of a pair of laminated films 8 and 10 which are vertically arranged. The laminated films 8 and 10 are heat-weldable plastics such as polyethylene, polypropylene, polyacrylonitrile and polyvinyl chloride. Metal films 8b, 10 made of a metal having a thermal conductivity lower than that of aluminum with the films 8a, 10a on the innermost layer side.
b is the intermediate layer side, and the plastic films 8c and 10c of nylon, polyethylene terephthalate, etc., which have excellent puncture strength for protecting the outer surface of the outer package, are the outermost layer side, so that a three-layer structure is formed. The number of layers may be the number of the metal films 8b and 10b. If the number of layers of the plastic film is at least one on the inner layer side, the outer layer for protection may be omitted. Also, the number of layers of the plastic film may be arbitrary.

In the outer envelope body 4, the inner edges of the plastic films 8a, 10a of the innermost layer (12 and 14 in the figure) are butted against each other, and the three sides which are required portions of the edges are heat-welded. Then, the remaining one side which is the non-heat-welded portion is evacuated to reduce the internal pressure to a vacuum state in the vacuum chamber, and the non-heat-welded portion is heat-welded and sealed by the heat seal device provided in the vacuum chamber. It has a different structure.

The outer shape maintaining member 6 is inserted into the outer envelope body 4 before heat-sealing the outer envelope body 4 and serves as a constituent material for maintaining the outer shape of the outer envelope body 4 against the internal pressure. When the pressure is reduced in the outer envelope body 4 by accommodating the precipitated silica fine powder or the inorganic fine powder such as perlite fine powder 6a for performing the function or the fiber glass as the other, and storing the fine powder 6a in the form of a bag. Such as kraft paper 6b which prevents the fine powder 6a from scattering and which is breathable.
In addition, it is made of non-woven fabric or other air-permeable paper that has air permeability and heat sealability.

In the present invention, the metal films 8b and 10b are made of a metal having a thermal conductivity lower than that of aluminum. As this metal, most preferably lead, a lead-based alloy, tin, a tin-based alloy, an alloy of lead and tin, in terms of excellent workability into a film shape.
Alternatively, an alloy containing lead-based and tin-based, preferably permalloy, amber, chrome nickel steel in terms of low thermal conductivity,
Nickel chrome alloy, silicon steel, tungsten steel, manganese steel, cyclomal, cast iron, malleable cast iron, wrought iron, carbon steel,
Examples include chrome steel, nickel steel, and galvanized steel.

In the first embodiment, the film 8b made of a metal whose thermal conductivity is smaller than that of aluminum,
Since 10b is used, as in the case of using aluminum, the peripheral portion 12,
It is not necessary to remove the metal located at 14 and the slanted portions 16 and 18, and as a result, the outer envelope body 4 entirely has no portion through which gas easily permeates. Compared with the case where it is used, the heat insulation performance is remarkably improved.

FIG. 3 is a perspective view of a heat insulating panel according to a second embodiment of the present invention, FIG. 4 is a sectional view taken along the line BB of FIG. 3, and portions corresponding to FIGS. The same reference numerals are attached. In the heat insulating panel 20 of the second embodiment, the outer shape maintaining member 6 inserted into the outer envelope body 4 is used as the first embodiment.
Unlike, a closed cell organic foam, such as a open cell urethane foam, is sealed. In Example 1, the outer package 4 is the laminated film 8, 10 which is the innermost plastic film 8
In the second embodiment, the outer envelope 4 is the plastic film 8a of the innermost layer and the metal film 8 of the intermediate layer.
b, only the laminated film 8 composed of three layers of the outermost plastic film 8c has a three-sided shape in which three sides are heat-welded.

The other structure of the second embodiment is similar to that of the first embodiment. The sealing of the outer package is basically the same as that of the first embodiment, and the description thereof will be omitted.

In the second embodiment, since the open-cell urethane foam is used as the outer shape maintaining member 6, the structure as the outer shape maintaining member is simple and the structure is easier to manufacture than the first embodiment in which fine powder is inserted. Becomes

Although the heat insulating panel of the above-mentioned embodiment has a rectangular planar shape, it is not limited to this planar shape, and the planar shape may be arbitrary as long as it is a panel shape.

Although the heat insulating panel of the above-described embodiment has been described as an example of the heat insulating panel used for the refrigerator wall,
It is used as a heat insulation panel in places where heat insulation is required, such as machines and devices that require heat insulation and cold insulation. Furthermore, the internal pressure of the heat insulating panel includes not only a vacuum heat insulating panel that is completely vacuumed but also a heat insulating panel that has various internal vacuum pressures depending on the degree of heat insulation even if the internal pressure is not completely vacuum.

[0027]

As described above, according to the present invention, since a film made of a metal having a smaller thermal conductivity than aluminum is used, not only is the heat insulation performance superior to the case where aluminum is used, but also aluminum is used. There is no easy transfer of heat on the surface of the outer envelope when using, which eliminates the need to remove the metal located at the periphery of the outer envelope to block the heat, and as a result, the entire surface of the outer envelope is free of gas. Since there is no portion that easily permeates, the heat insulating performance is further improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a heat insulating panel according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view of a heat insulating panel according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along the line BB of FIG.

FIG. 5 is a cross-sectional view of a conventional heat insulation panel.

[Explanation of symbols]

 2,20 Heat-insulating panel 4 Outer package 6 External shape maintaining member 8 Laminated film 8a, 8c, Plastic film 8b, 10b Metal film 8c, 10c Plastic film

Claims (4)

[Claims] 1. An outer envelope body having a predetermined outer shape and a reduced pressure inside thereof in a predetermined heat insulation state, and an outer shape inserted into the outer envelope body for maintaining the outer shape of the outer envelope body against the reduced pressure. The outer envelope comprises a pair of at least two laminated films each having a heat-weldable plastic film on the inner layer side and a metal film on the outer layer side, and the inner layer side of each laminated film. The heat insulation panels are formed by heat-sealing the inner peripheral edges of the plastic films in a state of facing each other, and the metal film is made of a metal material having a thermal conductivity lower than that of aluminum. 2. The outer shape maintaining member includes an inorganic fine powder as a reinforcing material, and a breathable material for containing the fine powder and preventing the inorganic fine powder from scattering during a depressurization process inside the outer package. The heat insulation panel according to claim 1, wherein: 3. The heat insulation panel according to claim 1, wherein the outer shape maintaining member is made of an open-cell organic foam. 4. The metal material constituting the metal film having a lower thermal conductivity than aluminum is lead, a lead-based alloy,
The heat insulation panel according to any one of claims 1 to 3, which is made of tin, a tin-based alloy, an alloy containing lead and tin, or a metal similar thereto.