JPH07167377A - Vacuum insulation - Google Patents

Abstract

(57) [Summary] [Structure] Container 1 made of a multilayer film having a metal layer
The opening of 2 is covered with a passing paper 16, and the container 12 and the ventilation paper 1
The space surrounded by 6 is filled with an inorganic powder 17 such as silica, dried at 100 ° C. or higher, and then evacuated to heat the container end 18 and a container lid 18 made of a multilayer film having a metal foil or metal vapor deposition. It will be done. [Effect] The cost can be significantly reduced and the reliability can be improved.

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 material used in freezers, refrigerators and the like.

[0002]

2. Description of the Related Art A conventional vacuum heat insulating material of this type is constructed as shown in FIG. 2. In FIG. 2, 11 is a heat-resistant middle container, and 2 is a vent paper middle container made of non-woven fabric or the like. A space, which is a lid and is formed by heat-welding the entire circumferences of the end portions of the inner container 1 and the inner container lid 2, is filled with an inorganic core material 3 such as silica, and then placed in a drying furnace (not shown). After drying, the outer packaging material container 4 made of a multi-layer film containing aluminum foil is set, the outer packaging material lid 5 is set, and the three edges are heat-welded and placed in a vacuum chamber to be evacuated. The vacuum heat insulating material 9 is formed by heat welding the remaining one side in the vacuum chamber. In FIG. 2, 6 is a protective layer, 7 is a metal foil layer, and 8 is a gas barrier layer.

[0003]

According to the conventional vacuum heat insulating material having the above-mentioned structure, a heat-resistant outer packaging material container is formed by thermoforming, and the opening of the inner container is made of non-woven fabric or the like. Cover with a lid, fill the space surrounded by the inner container and the lid of the inner container with powder such as silica, and after filling and drying in a drying oven, use an outer packaging material container / lid of a gas barrier multi-layer film. There is a drawback that the processing process such as wrapping is complicated and the number of parts is large and the cost is high, and the shape of the middle container and the outer packaging material container does not match due to variations in shrinkage ratio after molding, etc.
There is a drawback that wrinkles occur at corners and the like, and reliability is reduced.

[0004]

DISCLOSURE OF THE INVENTION The vacuum heat insulating material of the present invention eliminates the above-mentioned drawbacks, and has a heat-resistant outer packaging material container of a multi-layer film having a gas barrier property to eliminate the middle container. Is.

[0005]

According to the present invention, in the above structure, the outer container is made of a film having gas barrier property and heat resistance, so that the inner container is eliminated, and the cost is greatly reduced and the reliability is improved. Is.

[0006]

EXAMPLE An example of the vacuum heat insulating material of the present invention will be described below with reference to FIG. In FIG. 1, an outer wrapping material container 12 of a vacuum heat insulating material 11 is a laminated sheet formed by a protective layer 13 of a plastic film, a metal foil layer 14, and a gas barrier layer 15 of a plastic having a gas barrier property and capable of being heat welded. It is formed.

The outer packaging material container 12 maintains the degree of vacuum in the container for a long period of time, and further satisfies the requirements of heat resistance of 100 ° C. or higher, heat welding (heat sealing), and moldability in thermoforming. A film is formed, for example,
A polyester (PET) film or oriented polypropylene (OPP) is used as the protective layer 13, an aluminum foil having a thickness of 5.5 μm is used as the metal foil layer 14, and an inorganic filler 2 such as talc or glass fiber is used as the plastic gas barrier layer 15.
0% polypropylene (PP), adhesive resin (A
D), ethylene vinyl alcohol copolymer (EVO
H), adhesive resin (AD), polypropylene (PP) containing 20% of inorganic filler are co-pressed.

[0008] Then, the entire circumference of the opening of the thermoformed outer packaging material container 12 is heated around the entire circumference of the inner lid 16 made of a non-woven fabric (ventilated paper) smaller than the outer dimensions of the outer packaging material container 12 by an impulse heat welding machine. After welding, the outer packaging material container 12 and the inner lid 16
Silica (SiO ₂ ) as the core material 17 in the space surrounded by
Then, the core material 17 is placed in a drying oven at 120 ° C. for 2 hours to remove water contained in the core material 17.

Next, the outer wrapping material lid 18 which is taken out from the drying furnace and cut into the same size as the outer wrapping material container 12 from the multilayer laminate film having the aluminum vapor deposition layer is set, and the outer sides of the outer wrapping are heat-welded by the impulse heat-welding machine. After that, put it in the vacuum chamber and evacuate from one side that is not heat welded,
When a predetermined degree of vacuum is reached by an impulse heat welding machine provided in the vacuum chamber, heat welding is performed to keep the inside of the container airtight, thereby forming the vacuum heat insulating material 11.

[0010]

EFFECTS OF THE INVENTION Since the vacuum heat insulating material of the present invention has the above-mentioned structure, the inner container can be eliminated, and the cost can be largely reduced. It is possible to improve reliability by eliminating fitting mismatches and wrinkles. Further, since the material composition has good moldability, deformation after molding is eliminated and productivity can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of a vacuum heat insulating material of the present invention.

FIG. 2 is a cross-sectional view of essential parts showing an example of a conventional vacuum heat insulating material.

[Explanation of reference numerals] 11 vacuum heat insulating material 12 outer packaging material container 13 protective layer 14 metal foil layer 15 gas barrier layer 16 inner lid 17 core material 18 outer packaging material lid

Claims (4)

[Claims] 1. An opening of a container made of a multilayer film having a metal layer is covered with a ventilation paper, and a space surrounded by the container and the ventilation paper is filled with an inorganic powder such as silica and dried at 100 ° C. or higher. After that, the container is evacuated, and the container end is thermally welded to the container lid made of a multilayer film having a metal foil or metal vapor deposition. 2. The vacuum heat insulating material according to claim 1, wherein the container of the multilayer film is made of polypropylene, aluminum foil, polypropylene with an inorganic filler, ethylene vinyl alcohol copolymer, polypropylene with an inorganic filler. . 3. The vacuum heat insulating material according to claim 1, wherein the container for the multilayer film is made of polyester, aluminum foil, polypropylene with inorganic filler, ethylene vinyl alcohol copolymer, polypropylene with inorganic filler. . 4. The vacuum heat insulating material according to claim 2 or 3, wherein the content of the filler of the polypropylene containing the inorganic filler is set to 20% or more.