JP2012057745A - Vacuum heat insulation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum heat insulation material that hardly receives breakage caused by an external force, and has superior handling performance.SOLUTION: The vacuum heat insulation material constituted of a core material which is composed of at least a fiber aggregate and a film-shaped external wrapping material covering the core material and having gas barrier properties is characterized in that: an area of the external wrapping material is larger than an area of the core material; a region which protrudes exceeding a dimension of the core material is pasted by a thermal fusion layer of the external wrapping material when the core material is covered with the external wrapping material; the pasted region is bent in a shape along the core material and fixed to the external wrapping material with an adhesive tape; and the external face of the vacuum heat insulation material is covered with a hot-melt material.

Description

  The present invention relates to a vacuum heat insulating material suitable as a heat insulating material for home appliances, houses, vehicles and the like.

  In recent years, protection of the global environment due to the fear of global warming has been screamed, and energy conservation has been promoted under various circumstances. Not limited to home appliances, various technological innovations are being promoted. For example, in refrigerators, heat insulation materials using rigid urethane foam using chlorofluorocarbons having excellent heat insulation performance have been mainly used. However, due to the suspicion of ozone layer destruction, it has been forced to switch to gases such as isobutane, which have poor performance, and as a result, the structure has been changed to a combination of rigid urethane foam and a vacuum heat insulating material.

  The vacuum heat insulating material has a heat insulating performance that is ten times or more that of rigid urethane foam in terms of unit performance, but it is difficult to produce a free shape, and thus a flat shape is mainly used. In recent years, the trend toward larger and more complex vacuum insulation materials has been increasing for higher performance, but because of this, the surface area has been increasing, and there are many cases where the vacuum insulation material itself is damaged. It was. Such damage causes deterioration of each characteristic of the vacuum heat insulating material, and thus surface protection of the vacuum heat insulating material is required.

  In addition, the vacuum heat insulating material has a bonded portion where the fused portions are bonded together due to the structure, but the bonded portion is an obstacle in improving the performance of the vacuum heat insulating material. For this reason, it is currently folded by a human hand and attached with an adhesive tape, but the process is complicated and requires a lot of work, so the degree of damage is also increasing.

  The characteristics required of the vacuum heat insulating material outer packaging material include gas barrier properties, punching resistance, toughness, wear resistance, and the like. Usually, there is no material that can satisfy such characteristics alone, and therefore, a laminated film composed of components that satisfy each characteristic is used.

  However, due to the characteristics that the film structure and the vacuum heat insulating material itself are not used directly in the table, the satisfactory characteristics are not shown with respect to the direct stress from the outside.

  The following is mentioned as external protection of the conventional vacuum heat insulating material.

  There is a vacuum heat insulating material in which a board-shaped core material is covered with an outer packaging material having a gas barrier property, and a vacuum heat insulating material body in which the inside of the outer packaging material is decompressed and sealed in a vacuum is covered with a storage bag (Patent Document 1).

  There is one in which four sides of the bonded portion of the vacuum heat insulating material are bent to the surface side of the core material, and four corners of the bent bonded portion are covered with a hot melt material (Patent Document 2).

Japanese Patent No. 3680853 JP 2005-106094 A

  The vacuum heat insulating material described in Patent Document 1 has a problem that the work is troublesome twice because the vacuum heat insulating material once formed is further covered with a storage bag.

  The vacuum heat insulating material described in Patent Document 2 is covered with the hot melt material only at the four corners, so that it is strong against contact with the corners, but the outer packaging material surface is defenseless and easily damaged. Moreover, it is necessary to attach a hot-melt material to each of the four corners, and there is a problem that the operation is complicated.

  An object of this invention is to provide the vacuum heat insulating material which reduces the process of a bending process and has low deterioration of the vacuum heat insulating material characteristic by external force.

  In order to solve the above problems, the present invention provides a vacuum heat insulating material comprising at least a core material comprising a fiber assembly and a film-like outer packaging material having a gas barrier property covering the core material, wherein the area of the outer packaging material is the area of the core material. The part that exceeds the core dimension when the core material is covered with the outer packaging material is bonded by the heat-sealing layer of the outer packaging material, and the bonded site is bent into a shape along the core material. It is processed and fixed to the outer packaging material with an adhesive tape, and the outer surface of the vacuum heat insulating material is covered with a hot melt material.

  Further, the entire outer surface of the vacuum heat insulating material is covered with a hot melt material.

  Further, the entire outer surface of the vacuum heat insulating material is covered with a hot melt material, and surface smoothness is imparted by heat processing.

  Further, the entire outer surface of the vacuum heat insulating material is covered with a hot melt material, and the outer packaging material bonding portion is fixed with the hot melt material.

  In addition, the hot melt material is lower than the melting point of the heat sealing layer, and has a characteristic of reducing the residual stress of the outer packaging material by the annealing effect of the entire outer packaging material.

  Moreover, the hot melt material is processed by continuous dipping.

  Moreover, the front and back components were changed during the immersion treatment of the hot melt material.

  By covering the outermost part of the vacuum heat insulating material with the hot melt material, even if stress is applied due to contact with other members, the stress is absorbed by the hot melt material, so the influence on the vacuum heat insulating material itself is not affected. It can be minimized and damage can be suppressed. Moreover, although it is a vacuum heat insulating material with a rough surface normally, an unevenness | corrugation is relieve | moderated considerably by a hot-melt material.

  Or surface smoothness can be easily provided by surface processing, such as a heat roller.

  Or, when the outside of the vacuum insulation is covered with a hot melt material, the heat of the vacuum insulation is affected by the heat of fusion before the inside of the vacuum insulation is affected by the heat of foaming during urethane foaming in the refrigerator manufacturing process. The temperature rise of the main body is suppressed and thermal deterioration can be prevented.

  Or, by changing the front and back components at the time of immersion, it is possible to change the heat resistance and stickability according to the specifications.

Sectional drawing of the vacuum heat insulating material of this invention. Sectional drawing which shows the example of provision of the surface smoothness of the vacuum heat insulating material by this invention. The state figure of hot-melt material application | coating of the front and back by this invention. The heat insulation box sectional drawing filled with the foam heat insulating material. Sectional drawing of the vacuum heat insulating material outer packaging material by this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional view of the vacuum heat insulating material of the present invention, and FIG. 2 is a cross-sectional view showing an example of imparting surface smoothness to the vacuum heat insulating material of the present invention. FIG. 3 is a state diagram when a hot melt material is immersed in a vacuum heat insulating material. FIG. 4 shows a cross-sectional view of the heat insulation box filled with the foam heat insulating material. FIG. 5 is a cross-sectional view of the outer packaging material used in this example.

  A vacuum heat insulating material 1 shown in FIG. 1 includes an outer packaging material 2, an inner bag 3, a core material 4, an adsorbing material 5, and a hot melt material 10.

  FIG. 5 is a cross-sectional view of the outer packaging material used in this example. As the outer packaging material 2, a laminated film composed of four layers of the outermost layer 6, the moisture-proof layer 7, the gas barrier layer 8, and the heat sealing layer 9 in Example 1 was used. Specifically, the outermost layer 6 uses a stretched polypropylene resin having a low hygroscopicity of 30 μm, the moisture-proof layer 7 has a polyethylene terephthalate resin of 12 μm that is vapor-deposited on the inner surface as a vapor deposition layer 7a, and the gas barrier layer 8 has a vapor barrier layer 8a on the outer surface. 500 μm aluminum-deposited ethylene vinyl alcohol copolymer 12 μm, and the heat-sealing layer 9 were linear low density polyethylene 50 μm.

  Each element includes, for example, a polyamide resin as the outermost layer 6, a polyacrylic acid resin as the gas barrier layer 8, and vapor deposited films of inorganic materials such as silica as the vapor deposited films 7a and 8a. There is also a method of using a metal foil instead of the vapor-deposited film, but the metal foil is excellent in permeation resistance, but is not recommended because it has a disadvantage that the thermal conductivity is extremely high. Resins that can be thermally welded, such as high-density polyethylene resin, polypropylene resin, and polybutylene terephthalate resin, can be applied to the heat-sealing layer 9, respectively.

  Each component is bonded by a dry laminating method via a two-component curable urethane adhesive. However, a plastic material such as a melted polyethylene resin or polypropylene resin is used as an adhesive, or heat is applied to a plastic film by heat. There are no particular limitations on the adhesive or the laminating method, such as laminating or laminating with a biodegradable adhesive.

  The inner bag 3 is used for holding the core material 4 of the vacuum heat insulating material 1 and may be made of polyethylene resin, polypropylene resin, polyethylene terephthalate resin, polybutylene terephthalate resin, or the like that can be thermally welded. It is possible to use. The material of the inner bag 3 is preferably as low in hygroscopicity as possible and less outgas.

For the core material 4, a glass wool aggregate (density: 250 (kg / m ³ )) having an ultrafine fiber and an average fiber diameter of 4.1 μm was used.

  For the adsorbent 5, synthetic zeolite (Molecular Sieves 13X) was used. However, as long as it adsorbs moisture and gas, physical adsorption types such as silica gel and activated carbon, and chemicals such as calcium oxide, calcium chloride, and strontium oxide are used. It is also possible to use a reaction type adsorption type or the like.

  As a manufacturing method of the vacuum heat insulating material, the glass wool aggregate of the core material 4 was cut into a predetermined shape, and water was removed (dried at about 300 ° C./1 h). Further, the treated core material 4 was put in the inner bag 3 and compressed to a predetermined thickness. Next, the core material 4 is put into the outer packaging material 2 together with the adsorbent 5 for residual gas adsorption, and further heated to remove residual moisture as much as possible and put into a vacuum chamber until the internal pressure of the chamber becomes 1.3 Pa. After exhausting with a rotary pump and a diffusion pump, the end portion of the outer packaging material 2 was heat-sealed, and a vacuum heat insulating material 1 (size: 500 mm × 500 mm × 10 mm) was produced by vacuum sealing. At that time, the heat-adhered portion was bent into a shape along the core material and fixed to the outer packaging material with an adhesive tape. However, the fixing method is not limited to the adhesive tape.

  Examples of the hot-melt material include polyvinyl acetate and synthetic rubber, but polyvinyl acetate is preferable from the viewpoint of surface strength and handleability. However, when performing the process of attaching the vacuum heat insulating material itself, use of a synthetic rubber system is also conceivable.

  As a dipping method for the hot melt material 10, the vacuum heat insulating material 1 is sequentially fed by a continuous feeding device into a hot melt tank in which the vinyl acetate hot melt material is melted. At this time, when the hot melt material 10 of the same material on both sides is used, the vacuum heat insulating material 1 is immersed on the entire surface. When changing the material of the one-side front-side hot melt material 10a and the other back-side hot-melt material 10b, after immersing the entire surface in the hot-melt melting tank as shown in FIG. Or dipping treatment on only one side as shown in FIG. 3 (b). In this way, it is possible to use a composite method in which the front side is polyvinyl acetate and the back side is synthetic rubber.

(Comparative Example 1)
In this comparative example 1, as a process of the conventional product, the bonded part was bent manually and all the parts were held with an adhesive tape.

(Comparative Example 2)
In this comparative example 2, hot melt material was attached only to four corners, and workability and external stress were confirmed.

(Comparative Example 3)
In this comparative example 3, the vacuum heat insulating material 1 was put in the outer packaging material 2 to confirm the workability as a double structure.

(Comparison of embodiments)
Compared to the example, in Comparative Example 1, since the work of attaching all the bonded portions with tape occurs, there is a problem that the amount of work increases and it is easy to receive external stress during the work.

  In Comparative Example 2, the amount of sticking other than the four corners is not much different from Comparative Example 1, and the amount of work is large. Also, since many of the vacuum insulation materials are not protected, the handling precautions did not decrease much.

  In Comparative Example 3, in addition to an increase in the number of steps, there was a problem that the amount of the outer packaging material doubled.

  As described above, the vacuum heat insulating material 1 according to the present invention covers the entire vacuum heat insulating material 1 with the hot melt material 10 to thereby protect the vacuum heat insulating material itself and simplify the bonding part bending process procedure. Compared with the conventional method, the process can be greatly reduced and the defect rate can be reduced.

  Further, when the foam heat insulating material 21 is filled in the refrigerator, since the surface smoothness is improved, the fluidity at the time of filling the foam heat insulating material 21 is not hindered by the vacuum heat insulating material 1, and the foam heat insulating material is not disturbed. The good heat insulation box 20 which does not produce the 21 unfilled part can be shape | molded.

  Moreover, according to this invention, since the vacuum heat insulating material is covered with the hot-melt material, the vacuum heat insulating material is protected, and the defect of the vacuum heat insulating material is reduced. Therefore, it is possible to provide refrigerators, water heaters, and other household appliances that are required to have high thermal insulation performance with excellent cost performance.

DESCRIPTION OF SYMBOLS 1 Vacuum heat insulating material 2 Outer packaging material 3 Inner bag 4 Core material 5 Adsorbent material 6 Outermost layer 7 Moisture-proof layer 7a, 8a Deposition layer 8 Gas barrier layer 9 Hot melt layer 10 Hot melt material 10a Surface side hot melt material 10b Back surface side hot melt Material 11 Heat roller 20 Heat insulation box 21 Foam heat insulation

Claims (7)

In a vacuum heat insulating material comprising a core material comprising at least a fiber assembly and a film-like outer packaging material having a gas barrier property covering the core material,
The area of the outer packaging material is larger than the area of the core material,
When the core material is covered with the outer packaging material, the portion protruding beyond the core material size is bonded by the heat-sealing layer of the outer packaging material,
The bonded part is bent into a shape along the core material, and fixed to the outer packaging material with an adhesive tape,
An outer surface of the vacuum heat insulating material is covered with a hot melt material.   The vacuum heat insulating material according to claim 1, wherein an entire outer surface of the vacuum heat insulating material is covered with the hot melt material.   3. The vacuum heat insulating material according to claim 1, wherein the entire outer surface of the vacuum heat insulating material is covered with the hot melt material, and surface smoothness is provided by heat processing.   4. The vacuum heat insulation according to claim 1, wherein the entire outer surface of the vacuum heat insulating material is covered with the hot melt material, and the outer packaging material bonding portion is fixed with the hot melt material. Wood.   The hot-melt material is lower than the melting point of the heat-sealing layer, and has a characteristic of reducing the residual stress of the outer packaging material by the annealing effect of the entire outer packaging material. Vacuum insulation.   The vacuum heat insulating material according to claim 1, wherein the hot melt material is processed by continuous dipping.   The vacuum heat insulating material according to any one of claims 1 to 6, wherein components of the front and back surfaces are changed during the immersion treatment of the hot melt material.

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