JP6212975B2 - Vacuum insulation material - Google Patents

Description

  The present invention relates to an exterior material for a vacuum heat insulating material.

  Vacuum insulation material wraps the core material with the exterior material, seals the surrounding exterior material with the vacuum around the core material, and seals it, thereby making the thermal conductivity of the gas close to zero as much as possible. It is a heat insulating material with improved performance.

  The exterior material is required to have a gas barrier property in order to maintain the internal vacuum. However, since the conventional vacuum heat insulating material configured as described above uses aluminum foil as a gas barrier film, the heat insulation of the vacuum heat insulating material by the heat conduction that travels through the vacuum heat insulating material, the so-called heat bridge phenomenon. The effect is reduced.

  Therefore, in order to solve the heat bridge phenomenon, there is a vacuum heat insulating material using an exterior material in which the gas barrier film is changed to a gas barrier film having a deposited film instead of a metal foil (for example, Patent Document 1).

  In this vacuum heat insulating material, it is desirable to stack a plurality of gas barrier films in order to improve the gas barrier property of the exterior material (cover material), and furthermore, a material having a high gas barrier property is used as a supporting substrate for the deposited film. It is considered desirable.

  However, in the fin portion composed of the seal portion of the end portion of the exterior material of the vacuum heat insulating material and the portion where the core material is not present and the exterior materials are in close contact with each other in the vicinity of the vacuum, the core material is contained. Since the heat insulation performance is lower than that of the portion, the fin portion is bent to maintain the heat insulation performance. There is a problem that pinholes are generated during the bending, and the function as a vacuum heat insulating material is impaired.

JP 2010-138956 A

  In order to solve the above-mentioned problems, the applicant of the present application disclosed in Japanese Patent Application No. 2013-077604 a vacuum heat insulating material exterior material comprising a surface protective layer, a barrier layer, and a sealant layer. Furthermore, an exterior material constituted by laminating and using a stretched polypropylene film and a stretched nylon film and laminating an aluminum vapor-deposited polyethylene terephthalate film and an aluminum vapor-deposited ethylene-vinyl alcohol copolymer film as a barrier layer was proposed.

  In the exterior material described in the specification of Japanese Patent Application No. 2013-0777604, no pinholes could be confirmed even after repeated twisting as described in the examples.

  As described above, the exterior material described in the specification of Japanese Patent Application No. 2013-077764 does not generate pinholes due to bending, but nevertheless, the gas barrier property decreases after repeated twisting. Therefore, it was found that the desired performance cannot be obtained after bending.

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide an exterior material capable of preventing both the generation of pinholes due to bending and the deterioration of gas barrier properties.

That is, the invention according to claim 1 is an exterior material of a vacuum heat insulating material composed of a surface protective layer, a barrier layer, and a sealant layer in order from the outside,
The surface protective layer is used by laminating a stretched polypropylene film and a stretched nylon film, and the stretched polypropylene film is disposed on the outer surface side,
An exterior material for a vacuum heat insulating material, wherein an inorganic vapor-deposited film having a metal oxide thin film and a metal vapor-deposited film having a metal thin film are laminated on the barrier layer.

The exterior material of the vacuum heat insulating material of the present invention has the above-described configuration , and uses a stretched polypropylene film and a stretched nylon film for the surface protective layer, and the stretched polypropylene film is disposed on the outer surface side . Therefore, the vacuum heat insulating material can be kept in a high vacuum state even if it has high bending resistance and is used for a long period of time.

  In addition, since the barrier layer uses an inorganic vapor-deposited film having a metal oxide thin film and a metal vapor-deposited film having a metal thin film, the barrier property is extremely high, and the gas barrier property does not deteriorate due to bending. The vacuum state can be kept high. Also, since no metal foil is used, pinholes are less likely to occur. Moreover, the heat bridge phenomenon does not occur.

  In the inventions according to claims 2 to 3, the metal oxide thin film and the metal thin film are each specified as a thin film of a specific material.

  That is, the invention according to claim 2 is the vacuum insulation material exterior material according to claim 1, wherein the metal oxide thin film is an aluminum oxide thin film, while the invention according to claim 2 The metal thin film is an aluminum thin film, according to claim 1 or 2, wherein the vacuum heat insulating material is an exterior material.

  Moreover, the invention which concerns on Claims 4-5 specifies the material of the base film of the said inorganic vapor deposition film and the material of the base film of a metal vapor deposition film to the thin film of a specific film, respectively.

  That is, the invention according to claim 4 is the vacuum heat insulating material exterior material according to any one of claims 1 to 3, wherein a vapor deposition base material of the inorganic vapor deposition film is a polyethylene terephthalate film. The invention according to Item 5 is the exterior material for a vacuum heat insulating material according to any one of Claims 1 to 4, wherein the deposition base of the metal deposition film is an ethylene-vinyl alcohol copolymer film. . Polyethylene terephthalate film is excellent in strength and water resistance, and ethylene-vinyl alcohol copolymer film is inferior in water resistance, but has excellent oxygen barrier properties. And when an ethylene-vinyl alcohol copolymer film is used as a vapor deposition base material of a metal vapor deposition film, water resistance and oxygen barrier property can be improved over a long period of time.

Next, the invention according to claim 6 is characterized in that the sealant layer is a linear low density polyethylene film having a density of 0.935 g / cm ³ or less. It is the exterior material of the vacuum heat insulating material. Since the exterior material according to the present invention uses a linear low density polyethylene film having a density of 0.935 g / cm ³ or less for the sealant layer, the sealant layer is also flexible and the exterior material of the vacuum heat insulating material. As a result, the bending resistance is improved.

  The vacuum insulation material of the present invention is excellent in bending resistance, and since there is no generation of pinholes due to bending or deterioration of gas barrier properties, the vacuum insulation material using this exterior material can be used for a long period of time. Even in this case, a high vacuum state can be maintained, and the heat insulating performance can be maintained.

It is sectional drawing which showed typically an example of the exterior material of the vacuum heat insulating material of this invention. FIG. 3 is a cross-sectional view schematically showing a vacuum heat insulating material using an example of a vacuum heat insulating material of the present invention. It is sectional drawing explaining the bending part of the vacuum heat insulating material which used an example of the exterior material of the vacuum heat insulating material of this invention. FIG. 3 is a plan view schematically showing a vacuum heat insulating material using an example of a vacuum heat insulating material of the present invention.

  Hereinafter, embodiments for carrying out the present invention will be described.

  FIG. 1 is a cross-sectional view schematically showing an example of the vacuum insulation material of the present invention.

  The vacuum insulating material exterior material 1 of this example is configured by laminating a surface protective layer 10, a barrier layer 20, and a sealant layer 30 in order from the outside. The surface protective layer 10 is formed by laminating a stretched polypropylene film 11 on the outer surface and a stretched nylon film 12 on the inside thereof. By using such a two-layer surface protective layer 10, high bending resistance can be obtained. Although the stretched polypropylene film 11 has high bending resistance, the abrasion resistance is also improved by forming the stretched polypropylene film 11 on the outer surface. By using the stretched nylon film 12, the toughness is increased and the bending resistance is improved.

  The barrier layer 20 is configured by laminating an inorganic vapor deposition film 21 and a metal vapor deposition film 22 from the outside. By using the barrier layer 20 having such a two-layer structure, an extremely high barrier property can be obtained, and further, pinholes caused by bending and a decrease in barrier property can be prevented. Thereby, the heat bridge phenomenon can be solved.

  The inorganic vapor deposition film 21 is formed by forming a metal oxide thin film on the vapor deposition base material. As this metal oxide, silicon oxide, aluminum oxide (alumina), or the like can be used. Aluminum oxide (alumina) is preferable. Such a thin film of metal oxide can be formed by, for example, a vapor deposition method such as a vacuum deposition method, a sputtering method, or a CVD method. As a vapor deposition base material of the inorganic vapor deposition film 21, a polyamide film, a polyethylene terephthalate film, a polyvinyl chloride film, an ethylene-vinyl alcohol copolymer film, or the like can be used.

  Moreover, the metal vapor deposition film 22 forms the metal thin film in the vapor deposition base material. Aluminum can be used as this metal. The thin film can be formed by the vapor phase growth method. As the vapor deposition base material of the metal vapor deposition film 22, a polyamide film, a polyethylene terephthalate film, a polyvinyl chloride film, an ethylene-vinyl alcohol copolymer film, or the like can be used in the same manner as the vapor deposition base material of the inorganic vapor deposition film 21. it can.

In addition, it is desirable to use a polyethylene terephthalate film as the vapor deposition substrate of the inorganic vapor deposition film 21 and to use an ethylene-vinyl alcohol copolymer film as the vapor deposition substrate of the metal vapor deposition film 22. In this case, water resistance and oxygen barrier properties can be improved over a long period of time.

For the sealant layer 30, various polyethylene resins, polypropylene, and the like can be used. In particular, it is preferable to use a linear low density polyethylene film having a density of 0.935 g / cm ³ or less. The thickness is preferably 30 to 80 μm. If the density is higher than 0.935 g / cm ³ , for example, if the density is as high as 0.94 g / cm ³ , the bending resistance is deteriorated, which is not preferable.

  As a method of laminating each layer constituting the vacuum heat insulating material exterior material 1 of this example, a method by dry lamination using a two-component curable urethane adhesive and a method by extrusion lamination can be adopted.

  Hereinafter, a method of creating the vacuum heat insulating material 2 using the vacuum heat insulating material 1 of this example will be described.

  First, the two rectangular vacuum insulation materials 1 are sealed with the sealant layer 30 faced, three sides are heat-sealed in a bag shape, the core material 3 is inserted therein, and the vacuum is drawn to open the opening. It heat-seals and the heat sealing | fusion part 4 is provided in a periphery.

  As the core material 3, inorganic fibers such as glass fibers and organic fibers such as polystyrene fibers can be used. Moreover, what hardened powder and made into a board and a foamed resin can also be used. Moreover, you may use powder, such as foaming pearlite.

  When the core material 3 is inserted and evacuated to provide the heat fusion part 4, the heat fusion part 4 and the core material 3 are separated as shown in the cross-sectional view of FIG. A close contact portion 5 in which the front and back exterior materials 1 are in direct contact is formed. In the close contact part 5 and the heat fusion part 4, heat insulation cannot be expected.

  Therefore, as shown in the cross-sectional view of FIG. 3, the close contact portion 5 and the heat fusion portion 4 are bent to the outside air side so as not to come to the cold insulation or heat insulation side. A portion where the close contact portion 5 and the heat fusion portion 4 are bent is stopped with a flame retardant tape 6 as shown in FIG. In this way, a vacuum heat insulating material is completed.

  Even if the bent portion is made in this way, the vacuum insulation material 1 of the vacuum insulation material of this example is used, so the bending insulation is high and the vacuum insulation material is kept in a high vacuum state even when used for a long period of time. can do.

(Example)
A 20 μm-thick stretched polypropylene film 11 and a 15 μm-thick stretched nylon film 12 are used as the surface protective layer 10. A 12 μm-thick alumina-deposited polyethylene terephthalate film 21 and a 15 μm-thick aluminum-deposited ethylene-vinyl alcohol copolymer are used as the barrier layer 20. The combined film 22 was laminated and bonded in this order by a dry lamination method using a two-component curable urethane adhesive.

Subsequently, the sealant layer 30 having a thickness of 50 μm and a linear low density polyethylene film having a density of 0.923 g / cm ³ and an aluminum-deposited ethylene-vinyl alcohol copolymer film surface of the laminate are two-component curable. Using a urethane adhesive, bonding is performed by a dry lamination method to create a vacuum heat insulating material exterior material 1 composed of a surface protective layer 10, a barrier layer 20, and a sealant layer 30. The material was obtained.

(Comparative Example 1)
In the above example, an exterior material was manufactured in the same manner as in the example except that the stretched polypropylene film 11 was not used and the stretched nylon film 12 having a thickness of 15 μm was used as the surface protective layer 10.

(Comparative Example 2)
In the above embodiment, by using an aluminum-deposited polyethylene terephthalate film having a thickness of 12 μm instead of the alumina-deposited polyethylene terephthalate film 21 having a thickness of 12 μm, the barrier layer 20 has a thickness of the aluminum-deposited polyethylene terephthalate film 21 having a thickness of 12 μm. Except that the 15 μm aluminum vapor-deposited ethylene-vinyl alcohol copolymer film 22 was used, an exterior material was produced in the same manner as in the example.

  This exterior material is the same as the exterior material described in Japanese Patent Application No. 2013-0777604.

(Test method)
As an evaluation of the bending resistance of the vacuum insulation material of the example and the comparative example, the number of pinholes after being subjected to the gelboflex tester is measured, and the oxygen permeability is measured to measure the bending resistance. As a comparative evaluation.

  That is, first, the exterior materials of the vacuum heat insulating materials of the example and the comparative example were each cut into 210 mm × 297 mm, both ends of the 297 mm were bonded together, rounded into a cylindrical shape, and a cylindrical test piece was created.

  Hold both ends of this test piece with the fixed head and drive head of the Gelboflex tester, and while adding a 440 degree twist, narrow the distance between the fixed head and the drive head from 7 inches to 3.5 inches, and add a twist. While maintaining the state, the head interval is reduced to 1 inch, then the head interval is increased to 3.5 inches, and the head interval is increased to 7 inches while returning the twist. The test was performed 300 times at 25 ° C.

  Then, a penetrating flaw detection liquid was applied to the test piece after performing the gelbo test and checked to confirm the number of pinholes. Ten test pieces were used, and the average value was defined as the average number of pinholes.

  Moreover, about the test piece after performing the gelbo test, oxygen permeability was measured according to JISK7126-2. Table 1 shows the average number of pinholes and oxygen permeability before and after the gelbo test.

（考察）
まず実施例と比較例１とを対比して考察する。表面保護層１０として延伸ナイロンフィルム１２を使用した比較例１は、ゲルボ試験後の平均ピンホール数が１であるのに対して、表面保護層１０として延伸ポリプロピレンフィルムと延伸ナイロンフィルム１２との積層体を使用した実施例では平均ピンホール数が０である。この結果から、延伸ポリプロピレンフィルムの有無とピンホール数とが相関関係があることが分かる。

(Discussion)
First, the example and the comparative example 1 will be compared and considered. In Comparative Example 1 using the stretched nylon film 12 as the surface protective layer 10, the average number of pinholes after the gelbo test is 1, whereas the surface protective layer 10 is a laminate of a stretched polypropylene film and a stretched nylon film 12. In an embodiment using a body, the average number of pinholes is zero. From this result, it can be seen that there is a correlation between the presence or absence of a stretched polypropylene film and the number of pinholes.

Next, an example and comparative example 2 are compared and considered. In both Examples and Comparative Example 2, the average number of pinholes after the gelbo test was 0, but a laminate of an aluminum vapor-deposited polyethylene terephthalate film and an aluminum vapor-deposited ethylene-vinyl alcohol copolymer film was used as the barrier layer. In Comparative Example 2, the oxygen permeability is reduced, whereas in the example using a laminate of an alumina-deposited polyethylene terephthalate film and an aluminum-deposited ethylene-vinyl alcohol copolymer film, the decrease in oxygen permeability is suppressed. It has been. From this result, it can be seen that there is a correlation between the kind of the deposited film and the decrease in oxygen permeability.

  As is clear from the examples, a stretched polypropylene film and a stretched nylon film are laminated on the surface protective layer, and an alumina vapor-deposited polyethylene terephthalate film and an aluminum vapor-deposited ethylene-vinyl alcohol copolymer film are laminated on the barrier layer. When used, pinholes do not occur and the gas barrier properties do not deteriorate.

  As described above, the vacuum insulation material according to the present invention is excellent in bending resistance, and suppresses the generation of pinholes and gas barrier properties caused by manufacturing folds, thereby reducing high-quality vacuum insulation. Material can be provided.

  Therefore, the vacuum heat insulating material using the vacuum heat insulating material of the present invention can be applied to any device or facility that needs to be kept cold or warm, such as a refrigerator, a freezer, a water heater, or a vending machine. Is possible. And it can contribute to a significant energy-saving and space-saving by using the exterior material of the vacuum heat insulating material of this invention.

DESCRIPTION OF SYMBOLS 1 ... exterior material 2 ... vacuum heat insulating material 3 ... core material 4 ... heat fusion part 5 ... adhesion part 6 ... flame-retardant tape 10 ... -Surface protective layer 20 ... Barrier layer 30 ... Sealant layer 11 ... Stretched polypropylene film 12 ... Stretched nylon film 21 ... Inorganic vapor-deposited film 22 having a metal oxide thin film ... Metal thin film Metal vapor deposition film

Claims (6)

In order from the outside, a vacuum insulation material consisting of a surface protective layer, a barrier layer, and a sealant layer,
The surface protective layer is used by laminating a stretched polypropylene film and a stretched nylon film, and the stretched polypropylene film is disposed on the outer surface side,
An exterior material for a vacuum heat insulating material, wherein an inorganic vapor deposition film having a metal oxide thin film and a metal vapor deposition film having a metal thin film are laminated on the barrier layer.   The vacuum insulation material exterior material according to claim 1, wherein the metal oxide thin film is an aluminum oxide thin film.   The vacuum insulating material exterior material according to claim 1, wherein the metal thin film is an aluminum thin film.   The vacuum insulating material exterior material according to any one of claims 1 to 3, wherein a vapor deposition substrate of the inorganic vapor deposition film is a polyethylene terephthalate film.   The vacuum insulating material exterior material according to any one of claims 1 to 4, wherein a vapor deposition base material of the metal vapor deposition film is an ethylene-vinyl alcohol copolymer film. The sealant layer, the outer package of the vacuum heat insulating material according to any of claims 1 to 5, wherein the density is less linear low density polyethylene film 0.935 g / cm ^3.

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