JPH07180794A - Vacuum heat insulating container material and vacuum heat insulating container - Google Patents

Abstract

PURPOSE:To improve heat insulating performance by stabilizing a position and size where metallic foil is omitted without using acid and alkali, and omitting the metallic foil in a band-shape larger than a crack. CONSTITUTION:A thermoplastic synthetic resin layer 4 is provided on one face of a metallic foil 2 whose tensile strength is less than 30N/15mm width through an adhesive agent layer 3, and a thermoplastic synthetic resin layer 6 is provided on the other face of the metallic foil 2 through an adhesive agent layer 5, and an omitted adhesive agent zone 7 is provided on the adhesive agent layer 5. The omitted adhesive agent zone 7 of a vacuum insulating container material 1 is provided so as to correspond to the side wall part of a formed container, and in forming the container, the metallic foil 2 is broken on account of a difference in elongation percentage between the metallic foil and the synthetic resin to form the omitted part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum heat insulating container material and a vacuum heat insulating container.

[0002]

2. Description of the Related Art Conventionally, glass fiber, foamed polyurethane or the like has been used as a heat insulation material for keeping warm and cold, but in view of various performances, foamed polyurethane is predominant. Generally, CFCs are used as the foaming agent in this foamed polyurethane, but due to environmental issues, the use of CFCs is planned to be discontinued, and alternatives to insulation materials using CFCs are being considered. ing.

Under the circumstances as described above, recently, vacuum heat insulating materials have begun to be used. This vacuum heat insulating material is obtained by filling a container or bag with a fibrous material such as glass fiber or ceramic fiber or a porous powder such as pearlite, and evacuating the interior to seal it.

The heat insulating performance of the above heat insulating material depends on the degree of vacuum inside. In order to maintain the vacuum inside the insulation,
If a metal foil such as an aluminum foil having a thickness of 7 μm or more is used for the container or bag, there is almost no infiltration of the foaming agent gas,
Although the degree of vacuum is maintained for a long period of time, the heat insulation performance is deteriorated due to the high thermal conductivity of the metal material.

On the other hand, when a synthetic resin material is used for the container or bag, the thermal conductivity is much smaller than that of the metal foil and there is no problem with the heat insulation performance, but the gas barrier property is worse than that of the metal foil and the degree of vacuum is maintained for a long time. Is difficult.

Therefore, a laminate of a metal foil and a synthetic resin material can be considered as the heat insulating material. However, even in such a configuration, heat conduction occurs through the laminated metal foils,
The heat insulation is reduced. Therefore, in order to prevent heat conduction, a metal foil in which the metal foil is to be adhered to the bag has been proposed (Japanese Utility Model Publication No. 60-142928).

[0007]

As a method of removing a part of a metal foil in this way, the metal foil having unnecessary parts removed in advance is stuck, or after the metal foil is stuck to the entire synthetic resin sheet, A means for removing only the metal foil of the part using acid or alkali is used. In addition, deep drawing using a laminated sheet of synthetic resin sheet and metal foil to break the metal foil by using the difference in elongation between the synthetic resin and the metal material when creating a tray-shaped container, etc. There is also.

However, the method using an acid or an alkali has problems in handling the acid or the alkali and treating the waste liquid thereof. In the latter method of breaking the metal foil, it is difficult to keep the breaking position constant, and the breaking size is a very fine crack, which causes a problem of discontinuity.

Therefore, an object of the present invention is to stabilize the position and size of the metal foil to be removed without using acid or alkali, and to remove the metal foil in a strip shape larger than the crack to improve the heat insulation performance. It is to further improve.

[0010]

In order to solve the above problems, the first invention is to provide one or more thermoplastic synthetic resins with an adhesive layer on at least one surface of a metal foil having a tensile strength of 30 N / 15 mm width or less. In the laminated material provided with layers, the adhesive material layer is provided with a cutout zone at a portion of the laminated material, which is expected to be on the side wall of the container.

The thermoplastic synthetic resin layer preferably comprises a partially saponified product of polyacrylonitrile or ethylene vinyl acetate.

In the second invention, the laminated body of the first invention is vacuum or pressure molded to form a container having a bottom wall and a side wall rising from the peripheral edge thereof.

[0013]

[Function] Since the adhesive layer for laminating the metal foil and the thermoplastic synthetic resin layer is provided with the cut-out zone, the metal foil and the synthetic resin layer are not separated during the vacuum or pressure forming in which the intended side wall is stretched. While the metal foil suppresses the elongation in the joined part, both parts show free movement in the unjoined part, i.e., the vacant zone, and the thermoplastic resin layer may grow greatly according to its original characteristics. And On the other hand, the elongation of the metal foil is so small that it cannot follow the elongation of the thermoplastic synthetic resin layer and the foil is broken. This phenomenon occurs over the entire length of the strip of the adhesive layer. Therefore, a strip-shaped cutout portion of the metal foil is formed on the side wall of the molded container.

The tensile strength of the metal foil is 30 N / 15.
When the width exceeds the mm width, the metal foil is largely broken, the thermoplastic synthetic resin layer after molding becomes too thin, and in some cases, the metal synthetic resin layer is broken, and a container which cannot be practically used is completed.

[0015]

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

As shown in FIGS. 1 and 2, the vacuum heat insulating container material 1 according to the present invention has a first thermoplastic synthetic resin layer 4 on one surface of a metal foil 2 with a first adhesive layer 3 interposed therebetween. The second thermoplastic synthetic resin layer 6 is provided on the other surface of the metal foil 2 via the second adhesive layer 5, and the adhesive deficient zone 7 is provided on the second adhesive layer 5. It is provided.

When the container material 1 is molded, the cut-out zone 7 is provided so as to correspond to a portion of the side wall 9 formed on the peripheral edge of the container bottom wall 8.

The metal foil 2 may be made of aluminum, copper, iron or the like, but is preferably a soft foil, particularly an aluminum soft foil. Its tensile strength is 3-30N / 15mm
The width and thickness are in the range of about 4 μm to about 30 μm. 3N /
If the width is less than 15 mm, many cracks occur in other parts of the metal foil during molding, while if it exceeds 30 N / 15 mm width, it breaks too much and causes problems in heat insulation, or thermoplastic synthetic resin of the outer layer. This is because the layer 4 or 6 may be too thin or may be broken. The preferred tensile strength is 5 to 10 N / 15 mm width and thickness of about 5 μ.
˜about 7 μ.

Polyester, polypropylene, polyethylene and the like are used for the first and second synthetic resin layers 4 and 6, but a partially saponified product of ethylene vinyl acetate or polyacrylonitrile which is excellent in gas barrier property is preferable. The thickness may be appropriately selected according to the size of the container, but is, for example, about 10 to 400 μm. Also,
The layers 4 and 6 are not limited to a single layer and may be a multilayer. The lamination method may be any method such as co-extrusion in addition to bonding with an adhesive.

An example of the preferred material 1 is a thickness of 20 μm.
Stretched polypropylene and tensile strength 5.9N / 15mm
Laminate of aluminum foil of width, partially saponified product of ethylene vinyl acetate of thickness 30μ and unstretched polypropylene (heat seal surface) of thickness 100μ, polyethylene terephthalate of thickness 12μ and tensile strength 6N / 15m
Examples include an aluminum foil having a width of m and a polyacrylonitrile having a thickness of 300 μ (heat-sealing surface).

Various kinds of adhesive can be used for the adhesive layer 3 or 5 for laminating the metal foil 2 and the synthetic resin layer 4 or 6, but urethane adhesive is preferable.

The first synthetic resin layer 4 can be formed by coating the metal foil 2. Further, the resin layer 4 may be omitted.

As shown in FIG. 3, adhesive deficient zones 7 and 7a may be formed on both the first and second adhesive layers 3 and 5. These cut-out zones 7 and 7a are provided at substantially corresponding positions in the illustrated case, but they can be provided so as to be displaced within the range of the portion planned for the side wall 9.

As shown in FIGS. 4 and 5, two strips of adhesive deficient strip 7, 7b may be provided. Of course, it may be more. Also in this case, as in the case of FIG. 3, the first adhesive layer 3 can be provided with one or more strips of adhesive deficient zone 7a.

The contours of the adhesive deficient zones 7, 7a, 7b are substantially quadrangular in the illustrated case, but various polygonal shapes, circular shapes, elliptical shapes, etc. can be selected according to the shape of the container. . Further, although the cut-out zone has a completely continuous and closed shape, it may be discontinuous in some cases.
Further, a resin having a weak adhesive force may be filled in the lacking zone.

The actual heat insulating material 1 is a long web as shown in FIG. 6, and adhesive deficient zones 7 are provided at equal intervals in this web.

The container material 1 as described above is formed into a tray-like container with a flange by vacuum forming, pressure forming, or a combination of vacuum forming and pressure forming. At this time, as shown in FIG. 7, since the elongation rates of the metal foil and the synthetic resin are different, the portion of the synthetic resin layer 6 corresponding to the adhesive deficient zone 7 is not restricted by the metal foil 2 and the original elongation. Since the metal foil 2 cannot follow the elongation, the metal foil 2 breaks,
The strip-shaped metal foil lacking portion 10 is formed.

Since the adhesive deficient zone 7 is formed at the portion corresponding to the side wall 9 as described above, the side wall 9 of the finished container 11 extends laterally as shown in FIG. The strip-shaped metal foil lacking portion 10 is formed. Therefore, heat conduction is blocked at this portion, so that the heat insulating performance is improved.

FIG. 9 shows an example of forming a heat insulating material for a heat and cold storage using the container 11 described above. As shown in the figure, a porous powder A such as pearlite is stored, a woven or non-woven fabric B such as glass fiber is placed on the inner circumference of the opening, charged into a vacuum chamber C, and heat-sealed with a lid 12. This lid 12 is also the heat insulating material 1
It has the same configuration as. The finished container 11 is stored in the partition wall of the heat insulation box.

[0030]

According to the present invention, as described above, an adhesive deficient zone is provided when the metal foil and the thermoplastic synthetic resin are bonded together, and the difference in elongation between the two is utilized during molding. Since the metal foil of the part corresponding to the missing zone is broken, fine cracks do not occur, and it is possible to reliably form a discontinuous part of a relatively large metal foil at a specific position. The performance can be further improved.

Further, since the cutout portion of the metal foil can be formed without using acid or alkali, it is advantageous in terms of pollution prevention and the like.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a material for a vacuum heat insulating container of the present invention.

FIG. 2 is a transverse sectional view of the same.

FIG. 3 is a cross-sectional view showing another example of the above.

FIG. 4 is a plan view showing another example of a material for a vacuum heat insulating container.

FIG. 5 is a transverse sectional view of the above.

FIG. 6 is a plan view showing an example of a web of a vacuum heat insulating container material.

FIG. 7 is a partially enlarged vertical sectional view showing an example of a vacuum heat insulating container.

FIG. 8 is a front view showing an example of a vacuum heat insulating container.

FIG. 9 is a cross-sectional view showing an example of further vacuum-sealing the same container.

[Explanation of symbols]

 1 Material for Vacuum Insulation Container 2 Metal Foil 3 First Adhesive Layer 4 First Thermoplastic Synthetic Resin Layer 5 Second Adhesive Layer 6 Second Thermoplastic Synthetic Resin Layer 7, 7a, 7b Adhesive Absence Belt 8 Bottom wall 9 Side wall 10 Strip-shaped metal foil cutaway portion 11 Vacuum heat insulation container

Claims (3)

[Claims] 1. A laminated material in which one or more thermoplastic synthetic resin layers are provided on at least one side of a metal foil having a tensile strength of 30 N / 15 mm width or less through an adhesive layer, and a container side wall of the laminated material is planned. A material for a vacuum heat insulating container, characterized in that a cutout zone of the adhesive layer is formed in a portion. 2. The thermoplastic synthetic resin layer is polyacrylonitrile, a partially saponified product of ethylene vinyl acetate,
Alternatively, the material for a vacuum insulated container according to claim 1, which is composed of one of unstretched polypropylene coextrudates. 3. The vacuum heat insulating container material according to claim 1 or 2 is molded to form a bottom wall and a side wall rising from the peripheral edge thereof, and a strip-shaped cutout portion of the metal foil is provided along the entire circumference of the side wall. Vacuum insulation container.