JPH0325510Y2 - - Google Patents

Description

[Detailed explanation of the idea]

"Industrial Application Field" The present invention relates to a vacuum heat insulating material that is used by being embedded in a heat insulating wall of a refrigerator or the like. "Prior art and its problems" Vacuum insulation materials are made by housing a core material made of a heat-insulating material such as powder, porous molded body, or glass fiber in a vacuum insulation bag (hereinafter referred to as a packaging bag). The inside of the tank was vacuumed under reduced pressure. By the way, the heat insulating performance of a vacuum heat insulating material depends on the degree of vacuum inside the material, so this type of heat insulating material has a property that the heat insulating performance decreases as the degree of vacuum decreases. If a metal material is used for the above-mentioned packaging bag, since the metal material hardly allows gas to pass through, the degree of vacuum within the insulation material can be maintained well, and a vacuum insulation material with little change in insulation performance over time can be obtained. However, in the case of such a vacuum insulation material made of a metal packaging bag, there is a disadvantage that a thermal bridge is formed by the metal at the side face portion parallel to the heat flow, and the insulation performance of the vacuum insulation material is deteriorated. On the other hand, when a wrapping bag made of plastic film is used, since plastic has a low thermal conductivity, it is possible to prevent a decrease in insulation performance due to thermal bridges. However, since plastic film has much higher gas permeability than metal materials, the vacuum retention properties of plastic film packaging bags are inferior.
There is a problem in that the insulation performance of vacuum insulation materials deteriorates significantly over time. Therefore, a plastic film with relatively low gas permeability (for example, a film made of polyester, polyvinyl alcohol, polyvinylidene chloride, etc.) is vapor-deposited with aluminum, and then a metal layer such as low-density polyethylene or high-density polyethylene is laminated as a heat-sealing layer. A wrapping bag made of a vapor-deposited laminate film has been proposed. However, since there are many pinholes in the metal-deposited layer, even if the vacuum insulation material is made of a package made of metal-deposited laminate film, it cannot sufficiently prevent gas permeation, and its service life is unsatisfactory. It wasn't. In order to deal with such problems, it has been proposed to produce vacuum insulation bags using a film laminated with aluminum foil. however,
Even when such a wrapping bag is used, the laminated aluminum foil forms a thermal bridge, so in order to prevent the thermal insulation performance from deteriorating due to this thermal bridge, it is necessary to use aluminum foil as thin as possible (maximum 30 μm). If the aluminum foil is made thin like this, the number of pinholes in the foil will increase significantly, so even if the vacuum insulation material is made of such a wrapping bag, the lifespan of the insulation material will be shortened. It was not possible to fully satisfy both the heat insulation performance and the heat insulation performance. ``Means for solving the problem'' Therefore, in the present invention, a metal foil laminate film laminated with metal foil and a metal vapor-deposited laminate film formed by vapor-depositing metal are joined and integrated at their peripheral edges. At the same time, the above-mentioned problems can be solved by using a vacuum insulation bag (wrapping bag) in which a metal foil laminate film is laminated with metal foil on the metal vapor-deposited laminate film side except for the above-mentioned jointed and integrated part. I planned. "Example" Hereinafter, the vacuum insulation material of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the vacuum heat insulating material of the present invention, in which reference numeral 1 indicates a core material made of a heat insulating material;
Reference numeral 2 is a packaging bag (vacuum insulation bag). The core material 1 is made of a heat insulating material, and the heat insulating material used for the core material 1 is powder made of inorganic materials such as fine perlite powder, calcium silicate powder, diatomaceous earth powder, aerosil, silica powder, or glass fiber. , fibrous bodies made of inorganic materials such as ceramic fibers, molded bodies of inorganic materials such as calcium silicate molded bodies and pearlite molded bodies, molded bodies made of organic materials such as hard urethane foam and styrene foam, or plastic powder, etc. , various types with low thermal conductivity can be used. The packaging bag 2 is made by integrally bonding a metal foil laminate film 3 and a metal vapor-deposited laminate film 4 at their peripheral edges, and further laminating a metal foil laminate film 5 on the metal vapor-deposited laminate film 4 side. This packaging 2 contains 1x
It is said to be in a reduced pressure vacuum state of about 10 <sup>-1</sup> Torr to 5 × 10 <sup>-1</sup> Torr. The metal foil laminate film 3 forming the wrapping bag 2
is made by laminating one or more metal foils, and in this example, as shown in FIG. 2, the outermost layer is a synthetic resin film 3a and a metal foil layer 3b.
and a heat-sealing layer 3c forming the innermost layer. The synthetic resin film 3a is made of a polyester film, a nylon film, a polyvinylidene chloride film, a biaxially oriented polypropylene film, a polyethylene terephthalate film, etc., each having a diameter of about 12 μm to 25 μm. In addition, metal foil layer 3b
Various metal foils such as aluminum foil, iron, stainless steel, and tin can be used for the vacuum foil layer 3b, but generally the vacuum foil layer 3b has a thickness of 9 μm, 15 μm, 20 μm,
It is formed from aluminum foil with a thickness of about 30 μm or more. The thermal adhesive layer 3c is usually made of polyolefin-based low density polyethylene (LDPE),
It is made of high-density polyethylene (HDPE), polypropylene (PP), etc. The metallized laminate film 4 forming the wrapping bag 2 has a metallized layer 4a, and in this example, as shown in FIG. 3, the metallized layer 4a,
Two layers of 4a are provided. This metal vapor-deposited laminate film 4 is made by laminating two films 4b and 4c provided with a metal vapor-deposited layer 4a, and a heat-sealing layer 4d is provided as the innermost layer. The films 4b and 4c suitably used here include:
Examples include aluminum-deposited polyester film, aluminum-deposited stretched polyvinyl alcohol film, and aluminum-deposited polyethylene terephthalate film with a thickness of about 12 μm to 25 μm. In addition, when the metal vapor deposition layer 4a is only one layer, the film 4
A polyvinyl alcohol film or the like having a thickness of about 12 μm to 25 μm can also be used for either of b and 4c. The metal vapor deposited layer 4a is formed by vapor depositing metal such as aluminum or nickel on a base film to a thickness of about 0.025 to 0.070 μm. Further, the heat sealing layer 4d of this metal vapor-deposited laminate film 4 is made of LDPE, similar to the heat sealing layer 3c of the metal foil laminate film 3 described above.
Made of HDPE, PP, etc. This metal vapor-deposited laminate film 4 and the metal foil laminate film 3 have heat-sealing layers 3c and 4d.
By heat-sealing, as shown in FIGS. 4 and 5, their peripheral edges 3d and 4e are joined and integrated to form the wrapping bag 2. A metal foil laminate film 5 is laminated on the metal vapor-deposited laminate film 4. This metal foil laminate film 5 is laminated on a surface A perpendicular to the heat flow direction (a in FIG. 5) of the vacuum heat insulating material, that is, on the central portion of the metal vapor-deposited laminate film 4 excluding the peripheral edge 4e. As shown in FIG. 3, this metal foil laminate film 5 is formed by laminating metal foils 5a, and in this example, a protective film 5b, a metal foil 5a, and an adhesive layer 5 are laminated together.
A structure in which c and c are sequentially laminated is used. As the protective film 5b constituting the metal foil laminate film 5, 12 μm polyester film, nylon film, polyvinylidene chloride film, biaxially oriented polypropylene (OPP) film, etc. are generally used. Further, various metal foils can be used for the metal foil 5a, including 9 μm, 15 μm,
Aluminum foil with a thickness of about 20 μm, 30 μm or more is preferably used. The adhesive layer 5c is for laminating the metal laminate film 5 on the metal vapor-deposited laminate film 4, and is made of an adhesive, a dry lamination adhesive, or the like. When this vacuum insulation material is housed in a double wall such as a refrigerator and fixed with urethane foam, the adhesive layer 5c is exposed to Freon gas, so this adhesive layer 5c is made of polyurethane that is not likely to be deteriorated by Freon gas. It is preferable to use a type adhesive or the like. "Function" With the vacuum insulation material having such a structure, gas permeation from the side of the metal foil laminate film 3 forming the packaging bag 2 is almost completely prevented, and gas permeation from the side of the vacuum evaporated laminate film 4 is also prevented. Most of this is prevented by the laminated metal foil laminate film 5, thereby significantly preventing the deterioration of the heat insulation performance over time. Moreover, the metal foil laminate film 5 is provided only on the surface A perpendicular to the heat flow direction a of the metal vapor-deposited laminate film 4, and the peripheral edge 3
Since the metal foil laminate films 3 and 5 do not extend to the integrated joint portions d and 4e, a thermal bridge is not formed by the metal foil laminate films 3 and 5 at the side frame portion B of the vacuum insulation material (see Fig. 5). This prevents deterioration of insulation performance due to ``Example'' A wrapping bag 2 which is a vacuum insulation material of the present invention was produced as a prototype, and its effectiveness was investigated. The following films were used for each of the films 3, 4, and 5 forming the wrapping bag 2. As the metal foil laminate film 3,
A film in which 12 μm polyethylene terephthalate film (PET), 9 μm aluminum foil, and 60 μm HDPE were sequentially laminated was used. Metal vapor deposited laminate film 4 has a thickness of 12 μm.
A film in which two aluminum-deposited polyethylene terephthalate films (VM-PET) and 60 μm HDPE were sequentially laminated was used. Metal foil laminate film 5 has 12μmET
Film and 9μm aluminum foil are laminated, adhesive layer 5
A material coated with a dry laminating adhesive was used as c. A metal foil laminate film 5 corresponding to 70% of the area of the metal foil laminate film 4 is dry-laminated on the central part of the metal evaporated laminate film 4, and then this metal evaporated laminate film 4 and the metal foil laminate film 3 are heat-sealed at the peripheral parts 3d and 4e. Then, a bag was made into a packaging bag 2. For comparison, a wrapping bag without the metal foil laminate film 5 was also created. The moisture permeability and CO ₂ permeability of the packaging bag of the present invention and the packaging bag of a comparative example were measured. The results are shown in the table below.

[Table] From the results in the above table, the vacuum insulation material packaging bag 2 of the present invention
It was found that the vacuum insulation material of the present invention has excellent performance, with moisture permeation and gas permeation reduced to about 1/3 of that of the comparative example, and the vacuum insulation material of the present invention has a long service life. "Effects of the invention" As explained above, the vacuum insulation material of the invention has
In the vacuum insulation bag, a metal foil laminate film laminated with metal foil and a metal vapor-deposited laminate film on which metal is vapor-deposited are joined and integrated at their peripheral parts, and the above-mentioned joined and integrated part of this metal vapor-deposited laminate film is excluded. Since it is formed by laminating metal foil laminate films in which parts are laminated with metal foil, gas permeation is almost completely prevented, and the formation of thermal bridges is also prevented. Therefore, the vacuum heat insulating material of the present invention is an excellent heat insulating material that exhibits little change in heat insulating performance over time, has a long service life, and has good heat insulating performance. In addition, since the envelope that forms the vacuum insulation material of this invention has low gas permeation, it is possible to significantly reduce the use of expensive adsorbents that are conventionally added to vacuum insulation materials to maintain the vacuum level. It is possible to reduce the manufacturing cost of the heat insulating material.

[Brief explanation of drawings]

FIG. 1 is a partially sectional perspective view showing an embodiment of the vacuum insulation material of the present invention, and FIG. 2 is a sectional view showing a metal foil laminate film forming the wrapping bag of the same embodiment.
Fig. 3 is a cross-sectional view showing the metallized laminate film on which the metal foil laminate film of the packaging bag of the same example is laminated, Fig. 4 is a plan view showing the vacuum insulation material of the same example, and Fig. 5 is a cross-sectional view showing the vacuum insulation material of the same example. It is a sectional view showing the side part of a heat insulating material. 1...Core material, 2...Vacuum insulation bag (wrapping bag),
3...metal foil laminate film, 3b...metal foil layer, 3d...periphery, 4...metal vapor deposited laminate film, 4a...metal vapor deposited layer, 4e...periphery, 5...metal foil laminate film, 5a...
Metal foil, A...plane, a...heat flow direction.

Claims (1)

[Scope of Claim for Utility Model Registration] A vacuum insulation material made by housing a core material made of a heat insulating material in a vacuum insulation bag and evacuating the inside of the vacuum insulation bag, wherein the vacuum insulation bag is laminated with metal foil. A metal foil laminate film and a metal vapor-deposited laminate film on which a metal is vapor-deposited are integrally bonded at their peripheral edges, and a metal foil is laminated on a portion of the metal-vapor-deposited laminate film other than the above-mentioned jointed and integrated portion. A vacuum insulation material characterized by being formed by laminating foil laminate films.